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高永立
个人简介

高永立

“千人计划”特聘教授、博士生导师,超微结构与超快过程湖南省重点实验室主任,中南大学先进材料超微结构与超快过程研究所所长,高等研究中心主任。中南大学学士、美国普渡大学博士,美国罗切斯特大学终身教授,美国国家科学基金会那佛尔德大学(Norfold)CREST研究中心顾问,美国国家科学基金会项目评议委员。研究领域主要包括有机半导体表面及界面电子结构、有机半导体薄膜形成,金属及半导体中时间分辨的动力学过程及有机半导体界面的电子自旋注入。迄今已应邀请纂写学科综述文章或书籍专章8篇, 发表论文300余篇于自然-材料(Nature Materials),自然-光子学(Nature Photonics),物理评论快报(Physical Review Letters),物理评论(Physical Review B),应用物理快报(Applied Physics Letters)等世界知名刊物上。


1. 教育背景

1981/09 – 1986/06,Purdue大学,物理系,博士

1977/09 – 1981/06,中南矿冶学院(现中南大学),物理系,学士


2. 工作经历

2010年-至今,中南大学,超微结构与超快过程湖南省重点实验,教授。

1999年-至今,美国罗切斯特大学,教授

1994年-1999年,美国罗切斯特大学,副教授

1988年-1994年,美国罗切斯特大学,助理教授

1986年- 1988年,美国明尼苏达大学,博士后副研究员


3. 毕业研究生及去向

曹宁通 14级硕士 杭州士兰集成电路有限公司

万 闻 14级硕士 厦门大学(攻读博士学位)

吕 路 15级硕士 德国凯泽斯劳滕工业大学(攻读博士学位)

张 雷 15级硕士 新加坡国立大学(攻读博士学位)

欧阳俊 16级博士 中南大学(科学研究部)

谢海鹏 16级博士 中南大学(讲师)

张 红 16级硕士 湖南移动岳阳分公司

刘 鹏 16级硕士 杭州士兰集成电路有限公司


欢迎本科生、硕士生、博士生、博士后加盟!

E-mail:ygao@csu.edu.cn

xhpxhpxhp89@csu.edu.cn

Tel:18229992614(谢老师)


科研方向
_________________________________________________________________________________________

1. 研究方向

有机半导体表面及界面的电子结构

有机半导体薄膜的的形成和形态

有机半导体界面的电子自旋注入


2. 主持项目

1)2014/01 - 2018/12,国家自然科学基金重点项目,有机半导体二维自旋输运及原型器件研究(11334014) ,320 万;

2)2012/01 - 2015/12,国家自然科学基金面上项目,有机半导体自旋的注入和反转机理(51173205),60 万;


3. 近期的研究

Angle-resolved energy distributions curves of CH3NH3PbBr3, measured along ΓX and along ΓM.We studied the electronic structure of CH3NH3PbBr3 single crystal (001) surface with ARPES and IPES. The high quality of the smooth surface was confirmed by AFM and SEM. The elemental composition was investigated by XPS with a ratio close to the ideal value. Highly reproducible dispersive features of valence bands were observed with symmetry at the BZ center and boundaries. The four VB peaks are composed of Pb-s and Br-p orbitals as theoretical models predicted, and had different band dispersion widths. The largest dispersion came from the lowest binding energy band, being ~0.73 eV and ~0.98 eV for ΓX and ΓM directions, respectively. The measured band dispersions correspond to an effective hole mass as ~0.59 m0 and a lower limit of the hole mobility of 33.90 cm2V-1s-1 from the tight-binding fitting (C.C. Wang et al.,Phys. Chem. Chem. Phys., in press).


The UPS and XPS spectra of LSMO substrate.(a) Cut-off region of UPS, (b) O 1s core level, and (c) Mn2p1/2 core level of XPS. Inset: LEED pattern of LSMO. We investigated the energy level alignment and electronic structure evolution of the C60/LSMO interface. A total upward band bending of 0.72 eV was observed when the C60 film thickness increases from 0.5 to 8.0 nm, indicating an n-type to p-type transition of the film. The oxygen is proven to diffuse from LSMO to the C60 film. The n-p transition is ascribed to the diffused oxygen that acts as p-dopant of the C60 over layer (H.P. Xieet al. Appl. Phys. Lett.108, 011603 (2016)).

We have investigated the degradation mechanisms ofCH3NH3PbI3 using XPS and XRD. CH3NH3PbI3 films with the right atomic ratio and crystal structure were successfully fabricated by co-evaporation. We find that the CH3NH3PbI3film is not sensitive to oxygen. It is quite sensitive to moisture, and the interactions can be characterized in two stages. The first stage is for H2O exposure less than about 2 × 1010L, in which H2O acts as an n-dopant and the integrity of the perovskite remains intact. The first stage ends when the surface of the perovskite becomes highly n-doped. Higher exposure leads to the second stage when the perovskite quickly decomposes. The decomposition is characterized by the complete removal of N and part of I. The remnants of the film on the surface are crystalline PbI2, hydrocarbon complex, and O, the latter of which most likely from the adsorption of H2O on the surface. A model of water-catalyzed vaporization (WCAV) is proposed based on our observations (Y.Z. Liet al., J. Phys. Chem. C 119, 23996 (2015)).


Schematic energy level alignment at the NPB/MoO3/PEN/C60/LiF/Alq3 interfaces and proposed mechanisms of holes and electrons generation. We investigated the interfacial electronic structure and the energy level alignment of MoO3 and LiFmodifiedPEN/C60-based CGL using UPS. As the charge generation unit, a dipole and a band bending were observed at the PEN/C60 interface. The energy level offset between the LUMO of C60 and the HOMO of PEN was measured to be 0.83 eV, which was in fact significantly smaller after considering the Urbach tail states. It was very beneficial for charges to generate and transport. High-density electrons and holes accumulated on the n-type C60 and p-type PEN, respectively, in the vicinity of the PEN/C60junction, would be swept away from the PEN/C60interface in opposite directions under external electric field and built-in field (X. Liu et al., Org. Elec. 17, 325 (2015)).


Criteria for MoOx to be effective with different organicmaterials. The horizontal dashed lines from the top to the bottom are criteria for one day air exposed, 450 _C vacuum annealed after 1 h air exposure, and as deposited MoOx, respectively. If the HOMO of a given organic material is above one of the lines, it will enjoy the full benefit for hole injection/extraction by the MoOx insertion layer treated corresponding to the lines (C.G. Wang et al., J. Vac. Sci. Tech.B32, 040801 (2014)).


学术成果
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学术成果


1、论文推荐

【1】Cinchetti, M., Heimer, K., Wüstenberg, J.-P., Andreyev, O., Bauer, M., Lach, S., Ziegler, C., Gao, Y. & Aeschlimann, M., Determination of spin injection and transport in a ferromagnet/organic semiconductor heterojunction by two-photon photoemission, Nature Material, 8, 115 (2009).

【2】Gao,Y., Surface Analytical Studies of Interfaces in Organic Semiconductor Devices, Materials Sci. Engr. Rep. 68, 39 (2010). (应邀学科综述)



2、年度期刊论文

2017年

[1] Congcong Wang, Benjamin R. Ecker, Haotong Wei, Jinsong Huang, Jian-Qiao Meng, and Yongli Gao, “Valence Band Dispersion Measurements of Perovskite Single Crystal with Angle-resolved Photoemission Spectroscopy,” Phys. Chem. Chem. Phys., in press.

[2] Chuan Qian, Jia Sun, Ling-An Kong, Guangyang Gou, Menglong Zhu, Yongbo Yuan, Han Huang, Yongli Gao, and Junliang Yang, “High-Performance Organic Heterojunction Phototransistors Based on Highly Ordered Copper Phthalocyanine/para-Sexiphenyl Thin Films,” Adv. Funct. Mater. 2017, 1604933 (2017).


2016年

[3] Shuigen Li, Bingchu Yang, Runsheng Wu, Chen Zhang, Chujun Zhang, Xiao-Fang Tang, Gang Liu, Peng Liu, Conghua Zhou, Yongli Gao, Jian-Qiao Meng, Junliang Yang, “High-quality CH3NH3PbI3 thin film fabricated via intramolecular exchange for efficient planar heterojunction perovskite solar cells,” Org. Elec. 39, 304 (2016).

[4] Xiaohong Li, Kunhong Hu, Bosai Lyu, Jingdi Zhang, Yingwei Wang, Peng Wang, Si Xiao, Yongli Gao, and Jun He, “Enhanced Nonlinear Optical Response of Rectangular MoS2 and MoS2/TiO2 in Dispersion and Film,” J. Phys. Chem. C120, 18243 (2016).

[5] Guangyang Gou, Guozhang Dai, Chuan Qian, Yufeng Liu, Yan Fu, Zhenyang Tian, Yinke He, Lingan Kong, Junliang Yang, Jia Sun, and Yongli Gao, “High-performance ultraviolet photodetectors based on CdS/CdS:SnS2 superlattice nanowires,” Nanoscale 8, 14580 (2016).

[6] Han Huang, Yingbao Huang, Shitan Wang, Menglong Zhu, Haipeng Xie Lei Zhang, Xiaoming Zheng, Qiliang Xie, DongmeiNiu, and Yongli Gao, “Van DerWaalsHeterostructures between Small Organic Molecules and Layered Substrates,” Crystals 6, 113 (2016).

[7] Zhang Yu-He, Niu Dong-Mei, Lü Lu, Xie Hai-Peng, Zhu Meng-Long, Zhang Hong, Liu Peng, Cao Ning-Tong, and Gao Yong-Li, “Adsorption, film growth, and electronic structures of 2,7-dioctyl[1]benzothieno-[3,2-b][1]benzothiophene (C8-BTBT) on Cu (100),” ActaPhysicaSinica 65, 157901 (2016).

[8] Xiaotao Hu, Jia Sun, Chuan Qian, Fangmei Liu, Junliang Yang, Guang-hua Guo and Yongli Gao, “Low contact resistance in solid electrolyte-gated ZnO field-eect transistors with ferromagnetic contacts,” J. Mater. Chem. C4, 150 (2016).

[9] Lin Li, Xiaoliang Liu, Lu Lyu, Runsheng Wu, Peng Liu, Yuhe Zhang, Yuan Zhao, Hongyang Wang, DongmeiNiu, Junliang Yang, and Yongli Gao, “Modification of Ultrathin NPB Interlayer on the Electronic Structures of the CH3NH3PbI3/NPB/MoO3 Interface,” J. Phys. Chem. C120, 17863 (2016).

[10] Qiao Hu, Han Wu, Jia Sun, Donghang Yan, Yongli Gao, and Junliang Yang, “Large-area perovskite nanowire arrays fabricated by large-scale roll-to-roll micro-gravure printing and doctor blading,” Nanoscale 8, 5350 (2016).

[11] Song Hao, Bingchu Yang, and Yongli Gao, “Quenching induced fracture behaviors of CVD grown polycrystalline molybdenum disulfide films,” RCA Adv. 6, 59816 (2016).

[12] Jun Ouyang, Mengqiu Long, Xiaojiao Zhang, Dan Zhang, Jun He, and Yongli Gao, “Modulating the spin transport behaviors in ZBNCNRs by edge hydrogenation and position of BN chain,” AIP Adv. 6, 035116 (2016).

[13] Dan Zhang, Mengqiu Long, Fang Xie, Jun Ouyang, Hui Xu, and Yongli Gao, "Hydrogenations and electric field induced magnetic behaviors in armchair silicene nanoribbons," Sci. Rep. 6, 23677 (2016).

[14] F.M. Liu, C. Qian, J. Sun, P. Liu, Y.L. Huang, Y.L. Gao, and J.L. Yang, "Solution-Processed Lithium-Doped Zinc Oxide Thin-Film Transistors at Low Temperature between 100 and 300 C," Appl. Phys. A 122:311 (2016).

[15] X.F. Yu, W.J. Han, B.S. Lv, X.H. Li, S. Xiao, Y.L. Gao, and J. He, “Broadband spatial self-phase modulation of black phosphorous,” Opt. Let. 41, 1704 (2016).

[16] Yingwei Wang, Haoran Mu, Xiaohong Li, Jian Yuan, Jiazhang Chen, Si Xiao, Qiaoliang Bao, Yongli Gao, and Jun He, “Observation of large nonlinear responses in a graphene-Bi2Te3 heterostructure at a telecommunication wavelength,” Appl. Phys. Let. 108, 221901 (2016).

[17] Song Hao, Bingchu Yang, and Yongli Gao, “Fracture-induced nanoscrolls from CVD-grown monolayer molybdenum disulfide,” Phys. Status Solidi RRL 10, 549 (2016).

[18] Zhouming Zheng, Jie Jiang, Junjie Guo, Junliang Yang, and Yongli Gao, “Bio-inspired coplanar-gate-coupled ITO-free oxide-based transistors employing natural nontoxic bio-polymer electrolyte,” Org. Elec. 37, 474 (2016).

[19] Yulan Huang, Jia Sun, Jidong Zhang, Shitan Wang, Han Huang, Jian Zhang, Donghang Yan, Yongli Gao, Junliang Yang, “Controllable thin-film morphology and structure for 2,7-dioctyl[1] benzothieno[3,2-b][1]benzothiophene (C8BTBT) based organic field-effect transistors, ” Org. Elec. 36, 73 (2016).

[20] H.T. Wei, Y.J. Fang, P. Mulligan, W. Chuirazzi, H.H. Fang, C.C. Wang, B.R. Ecker, Y.L. Gao, M.A. Loi, L. Cao, and J.S. Huang, “Sensitive X-ray detectors made of methylammonium lead tribromide perovskite single crystals,” Nature Photonics 10, 333 (2016).

[21] Chenghao Cao, Chujun Zhang, Junliang Yang, Jia Sun, Shuping Pang, Han Wu, Runsheng Wu, Yongli Gao, and Chengbin Liu, “Iodine and Chlorine Element Evolution in CH3NH3PbI3xClx Thin Films for Highly Efficient Planar Heterojunction Perovskite Solar Cells,” Chem. Mat. 28, 2742-2749 (2016).

[22] H.P. Xie, D.M. Niu, L. Lyu, H. Zhang, Y.H. Zhang, P. Liu, P. Wang, D. Wu, and Y.L. Gao, “Evolution of the electronic structure of C60/La0.67Sr0.33MnO3 interface,” Appl. Phys. Lett. 108, 011603 (2016).

[23] Runsheng Wu, Bingchu Yang, Chujun Zhang, Yulan Huang, Yanxia Cui, Peng Liu, Conghua Zhou, YuyingHao, Yongli Gao, and Junliang Yang, “Prominent Efficiency Enhancement in Perovskite Solar Cells Employing Silica-Coated Gold Nanorods,” J. Phys. Chem. 120, 6996-7004 (2016).

[24] H. Zhang, D.M. Niu, L. Lyu, H.P. Xie, Y.H. Zhang, P. Liu, H. Huang, and Y.L. Gao, “Thickness dependence of interface electronic structure in C8-BTBT/Ni(100),” ACTA Phys. Sinica 65, 047902 (2016).

[25] Jian Xiong, Bingchu Yang, Runsheng Wu, Yulan Huang, Jia Sun, Shaohua Tao, Yongli Gao, and Junliang Yang, “Interface Degradation of Perovskite Solar Cells and its Modification using an Annealing-free TiO2 NPs Layer,” Org. Elec. 30, 30-35 (2016).

[26] Haipeng Xie, Xiaoliang Liu, Lu Lyu, DongmeiNiu, Qi Wang, Jinsong Huang, and Yongli Gao, “Effects of precursor ratios and annealing on electronic structure and surface composition of CH3NH3PbI3 perovskite films,” J. Phys. Chem. C120, 215-220 (2016).

[27] Peng Wang, Si Xiao, Xiaohong Li, Bosai Lyu, Yingbao Huang, Shubo Cheng, Han Huang, Jun He, and YongliGao, “Investigation of the dynamic bending properties of MoS2 thin films by interference colours,”Sci. Rep. 5, 18441,DOI: 10.1038/srep18441 (2016).

[28] C.C. Wang, Y.Z. Li, X.M. Xu, C.G. Wang, F.Y. Xie, and Y.L. Gao, “Degradation of Co-Evaporated Perovskite Thin Film in Air,” Chem. Phys. Lett. 649, 151 (2016).

[29] Lu Lyu, DongmeiNiu, Haipeng Xie, Ningtong Cao, Hong Zhang, Yuhe Zhang, Peng Liu, and Yongli Gao, “Orientation-dependent energy level alignment and film growth of 2,7diocty[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) on HOPG,” J. Chem. Phys. 144, 034701 (2016); doi: 10.1063/1.4939839


2015年

[30] Chuan Qian, Jia Sun, Lei Zhang, Haipeng Xie, Han Huang, Junliang Yang, and Yongli Gao, "Air-stable and high-performance organic field-effect transistors based on ordered, large-domain phthalocyanine copper thin film," Synth. Met. 210, 336 (2015).

[31] Peng Liu, Xiaoliang Liu, Lu Lyu,1 Haipeng Xie, Hong Zhang, DongmeiNiu, Han Huang, Cheng Bi, Zhengguo Xiao, Jinsong Huang, and Yongli Gao, “Interfacial electronic structure at the CH3NH3PbI3/MoOx interface,” Appl. Phys. Lett. 106, 193903 (2015).

[32] Y.Z. Li, X.M. Xu, C.C. Wang, C.G. Wang, F.Y. Xie, and Y.L. Gao, “Degradation by Exposure of Co-Evaporated CH3NH3PbI3 Thin Films,” J. Phys. Chem. C 119, 23996 (2015).

[33] L. Lyu, D.M. Niu, H.P. Xie, N.T. Cao, and Y.L. Gao, “Interface energy level alignment and thin film growth of C8-BTBT on MoS2,” Chinese J. Lumin. 36, 875 (2015).

[34] L. Ciammaruchi, C. Wang, Y. Gao, and C.W. Tang, “Delineation of degradation patterns of C-60-based organic solar cells under different environments,” J. Appl. Phys. 117, 245504 (2015); doi: 10.1063/1.4923091

[35] Y.Z. Li, X.M. Xu, C.C. Wang, C.G. Wang, F.Y. Xie, J.L. Yang, and Y.L. Gao, “Investigation on thermal evaporated CH3NH3PbI3 thin films,” AIP Adv. 5, 097111 (2015). doi:10.1063/1.4930545

[36] R.S. Wu, J. Xiong, P. Liu, C. Zhou, H. Huang, Y.L. Gao, B.C. Yang, J.L. Yang, “Efficient Electron-Blocking Layer-Free Planar Heterojunction Perovskite Solar Cells with a High Open-Circuit Voltage,” Org. Elec. 26, 265 (2015).

[37] C. Wang, X.L. Liu, C.C. Wang, J. Kauppi, and Y. Gao, “Electronic Structure Evolution in Doping of Fullerene (C60) by ultra-thin layer Molybdenum Trioxide,” J. Appl. Phys. 118, 085304 (2015).

[38] H. Xie, H. Huang, N. Cao, C. Zhou, D.-M. Niu, and Yongli Gao, “Effects of annealing on structure and composition of LSMO thin films,” Phys. B447, 14 (2015).

[39] Chuan Qian, Jia Sun, Lei Zhang, Han Huang, Junliang Yang, and Yongli Gao, “Crystal-Domain Orientation and Boundary of Organic Semiconductor Thin Film Investigated by in-situ Kelvin Probe Force Microscopy,” J. Phys. Chem. C119, 14965 (2015).

[40] Lei Zhang, Yingguo Yang, Lu Lvyu, Hong Zhang, Ningtong Cao, Haipeng Xie, Xingyu Gao, DongmeiNiu, Han Huang, and Yongli Gao, “Thickness Dependent Air-Exposure Induced Phase Transition of CuPc Ultra-Thin Films to Well-Ordered One-Dimensional Nanocrystals on Layered Substrates,” J. Phys. Chem. C119, 4217 (2015).

[41] Youzhen Li, Xuemei Xu, Chenggong Wang, Congong Wang, Fangyan Xie, Jinsong Huang, and Yongli Gao, “Surface Analytical Investigation on Organometal Triiodide Perovskit,” MRS Proceedings, in press.

[42] Jian Xiong, Bingchu Yang, Runsheng Wu, Chenghao Cao, Yulan Huang, Chengbin Liu, Zhikun Hu, Han Huang, Yongli Gao, and Junliang Yang, “Efficient and Non-hysteresis CH3NH3PbI3/PCBM Planar Heterojunction Solar Cells,” Org. Elec. 24, 106 (2015).

[43] Chenggong Wang, Xiaoliang Liu, and Yongli Gao, “Molecular Orientation of Copper Phthalocyanine (CuPc) Thin Films on Different Monolayers of Fullerene (C60) on SiO2/ Highly Oriented Pyrolytic Graphite (HOPG),” Appl. Phys. Lett. 106, 121603 (2015).

[44] Jin Xiao, Mengqiu Long, Xiaojiao Zhang, Jun Ouyang, Hui Xu, and Yongli Gao, “Theoretical predictions on the electronic structure and charge carrier mobility in 2D Phosphorus sheets,” Science Rep. 5, 9961 (2015).

[45] Fangmei Liu, Jia Sun, Si Xiao, Wenglong Huang, Shaohua Tao, Yi Zhang, Yongli Gao, and Junliang Yang, “Controllable Fabrication of Copper Phthalocyanine Nanostructure Crystals,” Nanotech. 26, 225601 (2015).

[46] Chuan Qian, Jia Sun, Junliang Yang, and Yongli Gao, “Flexible organic field-effect transistors on biodegradable cellulose paper with efficient reusable ion gel dielectrics,” RSC Adv. 5, 14567 (2015).

[47] I. Irfan and Y. Gao, “Improvement of Charge Transfer Between Electrode and Semiconductor by Thin Metal Oxide Insertion,” in Progress in High-Efficient Solution Process Organic Photovoltaic Devices, Ed. Y. Yang and G. Li, 67-99 (Springer-Verlag, Berlin, 2015).

[48] Chenggong Wang, Xiaoliang Liu, Congcong Wang, Zhengguo Xiao, Cheng Bi, Yuchuan Shao, and Jinsong Huang, and Yongli Gao, “Surface Analytical Investigation on Organometal Triiodide Perovskite,” J. Vac. Sci. Tech. B33, 032401 (2015).

[49] Chenggong Wang, Congcong Wang, Xiaoliang Liu, John Kauppi, Yuchuan Shao, Zhengguo Xiao, Cheng Bi, Jinsong Huang, and Yongli Gao, “Electronic Structure Evolution of Fullerene on CH3NH3PbI3,” Appl. Phys. Lett. 106, 111603 (2015).

[50] C. Fu, K. Savino, A. Zeng, B. Guan, D. Olvera, C. Wang, B. Song, H. Awad, Y. Gao, and M. Z. Yates, “Large Stored Charge in Electrochemically Synthesized Hydroxyapatite,” Chem. Mater. 27, 1164 (2015).

[51] X. Liu, C.G. Wang, C.C. Wang, I. Irfan, and Y. Gao, “Interfacial Electronic Structures of Buffer-modified C60/Pentacene-Based Charge Generation Layer,” Org. Elec. 17, 325 (2015).

[52] HaichaoDuan, Junliang Yang, Lin Fu, JianXiong, Bingchu Yang, Jun Ouyang, Conghua Zhou, Han Huang, and Yongli Gao, “Interface modification of organic photovoltaics by combining molybdenum oxide (MoOx) and molecular template layer,” Thin Solid Film 547, 146 (2015).

[53] J. Xiong, B. Yang, J. Yuan, L. Fan, X. Hu, H. Xie, L. Lv, R. Cui, Y. Zou, C. Zhou, D.-M. Niu, Y. Gao, and J.L. Yang, “Efficient organic photovoltaics using solution-processed, annealing- free TiO2 nanocrystalline particles as an interface modification layer,” Org. Elec. 17, 253 (2015).

[54] X. Liu, C.G. Wang, L. Lyu, C.C. Wang, Z.G. Xiao, C. Bi, J.S. Huang, and Y. Gao, “Electronic structures at the interface between Au and CH3NH3PbI3,” Phys. Chem. Chem. Phys. 17, 896 (2015).


2014年

[55] C.G. Wang, I. Irfan, and Y. Gao, “Protection of MoO3 High Work Function by Organic Thin Film,” Appl. Phys. Lett. 105, 181602 (2014).

[56] C.G. Wang, Irfan, and Y. Gao, “Manipulation of interface electronic structure by thin metal oxide films,” MRS Online Proceedings Library 1537, mrss13-1537-b03-06 (2014). (Invited paper)

[57] C.G. Wang and Y. Gao, “Electronic Structure Evolution in Doping of Fullerene (C60) by Molybdenum Trioxide,” Appl. Phys. Lett. 105, 111601 (2014).

[58] Qi Wang, Yuchuan Shao, Haipeng Xie, Lu Lyu, Xiaoliang Liu, Yongli Gao, and Jinsong Huang, “Qualifying composition dependent p and n self-doping in CH3NH3PbI3,” Appl. Phys. Lett. 105, 163508 (2014).

[59] W. Xia, H. Lin, H.N. Wu, Irfan, C. Wang, Y. Gao, and C.W. Tang, “Te/Cu Bi-layer: A Low Resistence Contact Buffer for Thin Film CdS/CdTe Solar Cell,” Sol. En. Mater. Sol. Cell 128, 411 (2014).

[60] N.T. Cao, L. Zhang, L. Lu, H.P. Xie, H. Huang, D.-M. Niu, and Y.L. Gao, “Van der Waals heterostructure of CuPc/MoS2(0001),” ACTA Phys. Sinica 63, 167903 (2014).

[61] C. Bi, Y. Shao, Y. Yuan, Z. Xiao, C. Wang, Y. Gao, and J. Huang, “Understanding the formation and evolution of interdiffusion grown organolead halide perovskite thin films by thermal annealing,” J. Mater. Chem. A2, 18508 (2014).

[62] S.L. Yan, M.Q. Long, X.-M. Li, Q.-T. Zhang, H. Xu, and Y.L. Gao, “Spin-filtering, rectifying and negative differential resistance behavior in Co(dmit)2 molecular devices with monoatomic (C, Fe, Au) electrodes,” Spin 116, 1440016 (2014).

[63] C. Wang, Irfan, X.L. Liu, and Y. Gao, “The Role of Molybdenum Oxide for Organic Electronics: Surface Analytical Studies,” J. Vac. Sci. Tech. 32, 040801 (2014). (Invited review)

[64] Z. Xiao, C. Bi, Y. Shao, Q. Dong, Q. Wang, Y. Yuan, C.G. Wang, Y. Gao, and J.S. Huang, “Efficient, high yield perovskite photovoltaic devices grown by interdiffusion of solution-processed precursor stacking layers,” Ener. Envir. Sci. 7, 2619 (2014).

[65] W. Huang, B. Yang, J. Sun, B. Liu, J. Yang, Y. Zou, J. Xiong, C. Zhou, and Y. Gao, “Organic field-effect transistor and its photoresponse using a benzo 1,2-b: 4,5-b ' difuran-based donor-acceptor conjugated polymer,” Org. Elec. 15, 1050 (2014).

[66] Y. Zhou, T. Kurosawa, W. Ma, Y. Guo, L. Fang, K. Vandewal, Y. Diao, C.G. Wang, Q. Yan, J. Reinspach, J. Mei, A.L. Appleton, G.I. Koleilat, Y.L. Gao, S.A Salleo, H. Ade, Dahui Zhao, and Z. Bao, “High Performance All-Polymer Solar Cell via Polymer Side-Chain Engineering,” Adv. Mat. 26, 3767 (2014).

[67] J. Xiong, B. Yang, C. Zhou, J. Yang, H. Duan, W. Huang, X. Zhang, X. Xia, L. Zhang, H. Huang, and Y. Gao, “Enhanced efficiency and stability of polymer solar cells with TiO2 nanoparticles buffer layer,” Org. Elec. 15, 835-843 (2014).

[68] Jin Xiao, Meng-Qiu Long Xinmei Li, Hui Xu, Han Huang, and Yongli Gao, “Theoretical Prediction of Electronic Structure and Carrier Mobility in Single-walled MoS2 Nanotubes,” Scientific Reposts 4, 4327 (2014).

[69] X. Liu, S.J. Yi, C.G. Wang, C.C. Wang, and Y. Gao, “Electronic Structure Evolution and Energy Level Alignment at C60/TAPC/MoOx/ITO Interfaces,” J. Appl. Phys. 115, 163708 (2014).

[70] H. Wang, P. Wei, Y. Li, J. Han, H.R. Lee, B.D. Naab, N. Liu, C. Wang, E. Adijanto, B.C. K. Tee, S. Morishita, Q. Li, Y. Gao, Y. Cui, and Z. Bao, “Tuning the threshold voltage of carbon nanotube transistors by n-type molecular doping for robust and flexible complementary circuits,” PNAS 111, 4776 (2014).

[71] X. Liu, C.G. Wang, Irfan, S.J. Yi, and Yongli Gao, “Effect of oxygen plasma treatment on air exposed MoOx thin film,” Org. Elec. 15, 977 (2014).

[72] W. Wan, H. Li, H. Huang, S. L. Wong, L. Lv, Y. L. Gao, and A. T. S. Wee, “Incorporating Isolated Molybdenum (Mo) Atoms into Bilayer Epitaxial Graphene on 4H-SiC(0001),” ACS Nano 8, 970 (2014)

[73] Jia Sun, Chuan Qian, Wenlong Huang, Junliang Yang, and Yongli Gao, “Ion-dependent gate dielectric characteristics of ion-1084conducting SiO2 solid-electrolytes in oxide field-effect transistors,” Phys. Chem. Chem. Phys. 16, 7455 (2014).

[74] J. Sun, W.L. Huang, C. Qian, J.L. Yang, and Y.L. Gao, “Mobility enhancement of SnO2 nanowire transistors gated with nanogranular SiO2 solid electrolyte,” Phys. Chem. Chem. Phys. 16, 1084 (2014).

[75] H. Ding and Yongli Gao, “Photoemission Studies of the Electronic Structure of Alkali Metal Doped Molecular Organic Semiconductors,” in Doping: Properties, Mechanisms and Applications, 107-220, Ed. L. Yu (Nova Science Publishers, New York, 2014).


2013年

[76] C.G. Wang and Y. Gao, “Manipulation of interface electronic structure by thin metal oxide films,” MRS Proc. 1537, 306 (2013).

[77] C.G. Wang, Irfan and Y. Gao, “Effect of air exposure of MoO3 film underneath thin CuPc layers,” MRS Proc. 1493, 287 (2013).

[78] B.C. Yang, H.C. Duan, C.H. Zou, Y.L. Gao, and J.L. Yang, “Ordered Nanocolumn-Array Organic Semiconductor Thin Films with Controllable Molecular Orientation,” Appl. Surf. Sci. 286, 104-108 (2013).

[79] Chenggong Wang, Irfan, Alexander Turinske, and Yongli Gao, “Orientation-dependent ionization potential of CuPc and energy level alignment at C60/CuPc interface,” Appl. Phys. B113, 361 (2013).


2012年

[80] M. Vosgueritchian, M. Ramuz, P. Wei, C. Wang, Y. Gao, and Z. Bao, “Evaluation of Solution Processable Carbon Based Electrodes for all Carbon Solar Cells,” ACS Nano, 6, 10384 (2012).

[81] C.G. Wang, Irfan, and Y. Gao, “Methods to Protect and Recover Work Function of Air Exposed Metal Oxide Films,” Proceedings of 2012 MRS Fall Meeting 1493 (2012) DOI: mrsf12-1493-h0809.

[82] Chenggong Wang, Irfan, Alexander Turinske, and Yongli Gao, “Pinning of fullerene lowest unoccupied molecular orbital edge at the interface with standing up copper phthalocyanine,” Thin Solid Film 525, 64 (2012).

[83] Irfan Irfan, Sachiko Graber, Franky So, and Yongli Gao,“Interplay of cleaning and de-doping in oxygen plasma treated high work function indium tin oxide (ITO),” Org. Elec. 13, 2028 (2012).

[84] Irfan, A.J. Turinske, Zhenan Bao, and Yongli Gao, “Work function recovery of air exposed molybdenum oxide thin films,” Appl. Phys. Lett. 101, 093305 (2012).

[85] Sondra L. Hellstrom, Michael Vosgueritchian, Randall M. Stoltenberg, Irfan Irfan, Mallory Hammock, Bril Wang, ChuangchengJia, Xuefeng Guo, Yongli Gao, Zhenan Bao, “Strong and stable doping of carbon nanotubes and graphene by MoOx for transparent electrodes,” Nano Lett. 12, 3574 (2012). DOI: 10.1021/nl301207e.

[86] H. Lin, W. Xia, H.N. Wu, C.W. Tang, I. Irfan, Y. Gao, “MoOx as an Efficient and Stable Back Contact Buffer for Thin Film CdTe Solar Cells,” MRS Online Proc. 1447 DOI: http://dx.doi.org/10.1557/opl.2012.1164 (2012).

[87] Irfan, H. Ding, Yongli Gao,W. Xia, H. Lin, and C. W. Tang, “Nitric-phosphoric acid etching effects on the surface chemical composition of CdTe thin film,” Thin Solid Films 520, 1988 (2012).

[88] Irfan and Y. Gao, “Metal-Oxides Hole Injection/Extraction Layer in Organic Semiconductor Devices,” ECS Transactions 35(19), 11 (2012).

[89] Irfan, Y. Gao, “Effects of exposure and air annealing on MoOx thin films,” J. Photonics for Energy 2, 021213-12 (2012).

[90] JegadesanSubbiah, Chad M. Amb, Irfan Irfan, Yongli Gao, John R. Reynolds, and Franky So, “High-Efficiency Inverted Polymer Solar Cells with Double Interlayer,” ACS Appl. Mater. Interf. 4, 866 (2012).

[91] Irfan Irfan, H. Lin, W. Xia, H. S. Wu, C. W. Tang, and Y. Gao, “The effect of MoOx inter-layer on thin film CdTe/CdS solar cell”, Sol. Ener. Mater. Sol. Cells 105, 86 (2012).

[92] Irfan, C.G. Wang, A.J. Turinske, and Y. Gao, “Methods to protect and recover work function of air exposed transition metal oxide thin films,” Proc. SPIE 8476, 847616 (2012).

[93] Hao Lin, Irfan, Wei Xia, Hsiang N. Wu, Yongli Gao, Ching W. Tang, “MoOx back contact for CdS/CdTe thin film solar cells: Preparation, device characteristics, and stability,” Sol. En. Mat. Sol. Cells, 99, 349 (2012).


2011年

[94] Irfan, H. Ding, and Y Gao, "Photoemission Spectroscopy Characterization of Attempts to Deposit MoO2 Thin Film," Int. J. Photoenergy, 2011, 314702, (2011). doi:10.1155/2011/314702

[95] Irfan, M. Zhang, H. Ding, C. W. Tang and Y. Gao, "Strong interface p-doping and band bending in C60 on MoOx", J. Org. Elec. 12, 1588 (2011).

[96] Irfan, H. Ding, F. So, and Y. Gao, “Oxide insertion layer in organic semiconductor devices,” J. Photo. Energy 1, 011105 (2011).

[97] H. Ding and Yongli Gao, “Rubrene electronic structure, interface energy level alignment, and growth dynamics,” Proc. SPIE 7778, 77780J (2011).


2010年

[98] H. Ding, Irfan, F. So, and Yongli Gao, “Interface study of insertion layers in organic semiconductor devices,” Proc. SPIE 7415, 74150J-74150J-14(2010).

[99] Irfan, H. Ding, Yongli Gao, C. Small, D.Y. Kim, J. Subbiah, and F. So, “Energy level evolution of air and oxygen exposed molybdenum trioxide films,” Appl. Phys. Lett. 96, 243307 (2010).

[100] M. Zhang, Irfan, H. Ding, Yongli Gao, and C. W. Tang, “Organic Schottky barrier solar cells based on MoOX/C60 junction,” Appl. Phys. Lett. 96, 183301 (2010).

[101] H. Ding, C. Reese, A. J. Mkinen, Z. Bao, and Y. Gao, “Angle-resolved photoemission study of rubrene single crystal,” Appl. Phys. Lett. 96, 222106 (2010).

[102] Irfan, H. Ding, and Yongli Gao, D.-Y. Kim, J. Subbiah, G. Sarasqueta, and F. So, “Energy level evolution of molybdenum trioxide inter-layer between indium-tin-oxide (ITO) and organic semiconductor,” Appl. Phys. Lett., 96, 073304 (2010).

[103] H. Ding and Y. Gao, “Evolution of the electronic structure of alkali-metal-doped copper-phthalocyanine (CuPc) on different metal substrates,” J. Org. Elec. 11, 1786 (2010).


2009年

[104] C. C. Zhao, X. H. Chen, C. Gao, M. K. Ng, H. Ding, K. Park, and Y. Gao, “New organic semiconductors for thin-film transistors: Synthesis, characterization, and performance of 4H-indeno[1,2-b]thiophene derivatives,” Synthetic Metals, 159, 995, (2009).

[105] Yasuhiro Shirai, Jason M. Guerrero, Takashi Sasaki, Tao He, Huanjun Ding, Guillaume Vives, Byung-Chan Yu, Long Cheng, Austen K. Flatt, Priscilla G. Taylor, Yongli Gao, and James M. Tour, “Fullerene/Thiol-Terminated Molecules,” J. Org. Chem. 74, 7885 (2009).

[106] Y. Gao, “Surface Analytical Studies of Interfaces in Organic Semiconductor Devices,” Materials Sci. Engr. Rep. 68, 39 (2009).

[107] Y. Gao, “Interface in Organic Semiconductor Devices: Dipole, Doping, Band Bending, and Growth,” in Organic Electronics :Materials, Processing, Devices, and Applications, Ed. F. So, 141 (Taylor & Francis CRC Press, New York, 2009).

[108] D.Y. Kim, F. So, and Y. Gao, “Aluminum phthalocyanine chloride/C-60 organic photovoltaic cells with high open-circuit voltages,” Sol. E. Mat. Sol. Cells 93, 1688 (2009).

[109] Do Young Kim, JegadesanSubbiah, Galileo Sarasqueta, and Franky So, Huanjun Ding, Irfan and Yongli Gao, “The effect of molybdenum oxide interlayer on organic photovoltaic cells,” Appl. Phys. Lett. 95, 093304 (2009).

[110] J. H. Wei, Y.L. Gao, and X.R.Wang, “Inverse Square-Root Field Dependence of Conductivity in Organic Field-Effect Transistors,” Appl. Phys. Lett. 94, 073301 (2009).

[111] Huanjun Ding, Kiwan Park, Yongli Gao, Do Young Kim and Franky So, “Electronic structure and interactions of LiF doped tris (8-hydroxyquinoline) aluminum (Alq),” Chem. Phys. Lett. 473, 92 (2009).

[112] H.J. Ding, Kiwan Park, and Y. Gao, “Evolution of the Unoccupied States in Alkali Metal-doped Organic Semiconductor,” J. Elec. Spec. Relat. Phen. 174, 45 (2009).

[113] H. Ding and Y. Gao, “Electronic structure at rubrene metal interfaces,” Appl. Phys. A95, 89 (2009).

[114] M. Cinchetti, K. Heimer, J.-P. Wüstenberg, O. Andreyev, M. Bauer, S. Lach, C. Ziegler, Y. Gao, and M. Aeschlimann, “Determination of spin injection and transport in a ferromagnet/organic semiconductor heterojunction by two-photon photoemission,” Nature Material, 8, 115 (2009).


2008年

[115] Y. Gao, “Organic/Metal Interface Properties,” in Introduction to Organic Optoelectronic Materials and Devices, Ed. S. Sun and L. Dalton, 637 (Taylor & Francis CRC Press, New York, 2008).

[116] H.J. Ding, Y. Gao, H. Wang, and D. Yan, “Band Bending and Debye Screening in F16CuPc/BP2T Ambipolar Organic Thin Film Transistor,” SPIE Proc. 7054, 70540C, (2008).

[117] K. Park, H. Ding, F. So and Y. Gao, “Mechanism of LiF interlayer for electron injection,” SPIE Proc. 7051, 70511V (2008).

[118] H. Ding, K.W. Park, and Y. Gao, “Electronic structure of doping in organic semiconductor,” SPIE Proc. 7051, 705111 (2008).

[119] Z.L. Zhang, T. Asano, H. Uno, R. Tero, M. Suzui, S. Nakao, T. Kaito, K. Shibasaki, M. Tominaga, Y. Utsumi, Y.L. Gaof, T. Urisu, “Fabrication of Si-based planar type patch clamp biosensor using silicon on insulator substrate,” Thin Solid Films 516, 2813 (2008).

[120] H. Ding, Y. Gao, M. Cinchetti, J.-P. Wustenberg, M. Sanchez-Albaneda, O. Andreyev, M. Bauer, and M. Aeschlimann, “Spin Injection and Spin Dynamics at the CuPc/GaAs Interface,” Phys. Rev. B78, 075311 (2008).

[121] H. Ding, K.W. Park, and Y. Gao, “Unoccupied State Evolution in Cs-Doped Copper Phthalocyanine,” MRS Proc. 1029, F04-03 (2008).

[122] H. Ding and Y. Gao, “Energy level alignment at the rubrene/metal interface,” MRS Proc., 1029, F04-03 (2008).

[123] H. Ding and Y. Gao, “Modification on the Electronic Structure of Organic Semiconductors by Alkali Metal,” ECS Trans. 11, 1 (2008).

[124] H. Ding, H. Wang, D. Yan, and Y. Gao, “Ambipolar Organic Thin Film Transistor and Electronic Structure of Interfaces,” ECS Trans. 11, 15 (2008).

[125] H. Ding and Y. Gao, “The role of LiF for the electron injection in tris-(8-hydroxyquinoline) aluminum” , ECS Trans. 11, 25 (2008).

[126] H. Ding, K. Green, and Y. Gao, “Electronic Structure Modification of Copper Phthalocyanine (CuPc) Induced by Intensive Na Doping,” Chem. Phys. Lett., 454, 229, (2008).

[127] T. He, H. Ding, N. Peor, M. Lu, D.A. Corley, B. Chen, Y. Ofir, Y. Gao, S. Yitzchaik, and J. Tour, “Silicon/Molecule Interfacial Electronic Modifications,” J. Am. Chem. Soc. 130, 1699 (2008).

[128] H. Ding and Y. Gao, “Evolution of the Unoccupied State in Cs-Doped Copper Phthalocyanine,” Appl. Phys. Lett. 92, 053309 (2008).


2007年以前

[129] H. Ding, Y. Gao, M. Sanchez-Albaneda, J.-P. Wustenberg, M. Cinchetti, O. Andreyev, M. Bauer, and M. Aeschlimann, “Spin Injection and Spin Dynamics at CuPc/GaAs(100) Interface,” MRS Proc. 965, S09-49 (2007).

[130] H. Ding and Y. Gao, “Photoemission Study of Oxygen and Au Modification of Doped Copper Phthalocyanine,” J. Appl. Phys. 102, 043703 (2007).

[131] H. Ding and Y. Gao, “Au/LiF/tris-(8-hydroxyquinoline) aluminum interfaces,” Appl. Phys. Lett. 91, 172107 (2007).

[132] Y. Gao, H. Ding, H. Wang, and D. Yan, “Electronic structure of interfaces between hexadecafluoro-phthalocyanine and 2,5-bis(4-biphenylyl) bithiophene,” Appl. Phys. Lett. 91, 142112 (2007).

[133] H. Ding and Y. Gao, “Reversal of Doping Induced Energy Level Shift in Organic Semiconductors,” Internat. J. Nanosci. 6, 125 (2007).

[134] H. Ding, S. Zorba, Y. Gao, L.P. Ma, and Y. Yang, “Photoemission study of tris(8-hydroxyquinoline) aluminum/aluminum oxide/tris(8-hydroxyquinoline) aluminum interface,” J. Appl. Phys. 100, 113706 (2006).

[135] N. J. Watkins, A. J. Mkinen, Y. Gao, M. Uchida, and Z. H. Kafafi, “Direct observation of the evolution of occupied and unoccupied energy levels of two silole derivatives at their interfaces with magnesium,” J. Appl. Phys. 100, 103706 (2006).

[136] S. Zorba, Y. Shapir, and Y. Gao, "Fractal-mound growth of pentacene thin films," Phys. Rev. B74, 245410 (2006).

[137] H. Ding and Y. Gao, “Alkali Metal Doping and Energy Level Shift in Organic Semiconductor Surfaces,” Appl. Surf. Sci. 252, 3943 (2006).

[138] B.H. Hamadani, H. Ding, Y. Gao, and D. Natelson, “Doping dependent chargeinjection in organic field-effect transistors,” Phys. Rev. B72, 235302 (2005).

[139] S. Pyo, L.P. Ma, J. He, Q.F. Xu, Y. Yang, and Y. Gao, “Experimental study on thickness-related electrical characteristics in organic/metal-nanocluster/organic systems,” J. Appl. Phys. 98, 54303 (2005).

[140] A. Tanaka, L. Yan, N.J. Watkins, Y. Gao, “Femtosecond Time-resolved Two-photon Photoemission Study of Organic Semiconductor Copper Phthalocyanine Film,” J. Elec. Spec. Relat. Phen.144, 327 (2005).

[141] H. Ding and Y. Gao, “Reversal of Doping Induced Energy Level Shift: Au on Cs-doped Alq,” Appl. Phys. Lett. 87, 851918 (2005).

[142] H. Ding and Y. Gao, “Electronic Structure of Cs Doping in Alq,” Appl. Phys. Lett. 86, 213508 (2005).

[143] S. Zorba and Y. Gao, “Feasibility of Static Induction Transistor with Organic Semiconductors,” Appl. Phys. Lett. 86, 193508 (2005).

[144] R. Krishnan, Q. Xie, J. Kulik, X.D. Wang, S. Lu, M. Molinari, Y. Gao, T.D. Krauss, P.M. Fauchet, “Effect of Oxidation on Charge Localization and Transport in a Single Layer of Silicon Nanocrystals,” J. Appl. Phys. 96, 654 (2004).

[145] S. Zorba and Y. Gao, “Growth Kinetics of Ordered Pentacene Thin Films,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

[146] N.J. Watkins and Y. Gao, “Energy Level Alignment of Pentacene and Dielectric Materials,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

[147] L. Yan, N.J. Watkins, S. Zorba, and Y. Gao, “Metal-Organic Interface Dipole and Thermodynamic Equilibrium,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

[148] Y. Gao and L. Yan, “Energy Level Shift in CuPc,” in Proc. Int. Conf. Synth. Metals 2004, (University of Wollongong, 2004).

[149] Y. Gao, “Interface Electronic Structure and Organic Photovoltaic Devices,” in Organic Photovoltaics, Ed. S. Sun and N. Sariciftci, 421 (Taylor and Francis, New York, 2004).

[150] N.J. Watkins, S. Zorba, and Y. Gao, “Interface Formation of Pentacene with Al2O3,” J. Appl. Phys. 96, 425 (2004).

[151] Serkan Zorba and Yongli Gao, “Organic Nanofilm Growth,” in Encyclopedia of Nanoscience and Nanotechnology, Ed. H.S. Nalwa, Vol 8, 271 (2004).

[152] N.J. Watkins and Y. Gao, “Interface Formation and Energy Level Alignment of Pentacene on SiO2,” J. Appl. Phys. 94, 5782 (2003).

[153] Y. Gao and Li Yan, “Cs Doping and Energy Level Shift in CuPc,” Chem. Phys. Lett. 380, 451 (2003).

[154] N.J. Watkins and Y. Gao, “Vacuum level alignment of pentacene on LiF/Au,” J. Appl. Phys. 94, 1289 (2003).

[155] A. Tanaka, N.J. Watkins, and Yongli Gao, “Hot-Electron Relaxation in the Layered Semiconductor 2H-MoS2 Studied by Time-Resolved Two-Photon Photoemission Spectroscopy,” Phys. Rev. B67, 113315 (2003).

[156] XiaoweiTeng, Donald Black, Neil J. Watkins, Yongli Gao, and Hong Yang, “Platinum-Maghemite Core-Shell Nanoparticles Using a Sequential Synthesis,” Nano Let. 3, 261 (2003).

[157] Serkan Zorba, Li Yan, Neil J. Watkins, and Yongli Gao, “Kinetic Roughening Study of Perylene on Glass and Au Substrates,” MRS Proc., in press.

[158] Li Yan, N.J. Watkins, C. W. Tang, and Yongli Gao, “Fermi Level Pinning in Cs Doped CuPc,” Synth. Met. 137, 1037 (2003).

[159] N. J. Watkins, Li Yan, S. Zorba, and Yongli Gao, “Photoemission spectroscopy study of the interface formation in organic thin film transistors,” SPIE Proc. 4800, 192 (2003).

[160] Serkan Zorba, Li Yan, Neil J. Watkins, and Yongli Gao, “Growth Front Kinetics of Perylene on Glass and Au Substrates,” SPIE Proc. 4801, 136 (2003).

[161] N. J. Watkins, Li Yan, S. Zorba, Yongli Gao, and C. W. Tang, “Evidence of Electron and Hole Transfer in Metal/CuPc Interfaces,” SPIE Proc. 4800, 248 (2002).

[162] Akinori Tanaka, TazumiNagasawa, Yuitsu Takeda, Neil J. Watkins and Yongli Gao, “Time-Resolved Two-Photon Photoemission Study of Dodecanethiolate-Passivated Ag Nanoparticles,” J. Phys. Soc. Japan 71, 3098 (2002).

[163] Serkan Zorba, Li Yan, Neil J. Watkins, and Yongli Gao, “Kinetic Roughening Study of Perylene on Glass and Au Substrates,” Appl. Phys. Lett. 81, 5195 (2002).

[164] N.J. Watkins, S. Zorba, L. Yan, and Y. Gao, “A Photoemission Spectroscopic Study of the Interface Formation in Organic Thin Film Transistors,” MRS Proc. 708, BB2.3 (2002).

[165] Li Yan, N. J. Watkins, S. Zorba, Yongli Gao, and C. W. Tang, "Thermodynamic Equilibrium and Metal-Organic Interface Dipole," Appl. Phys. Lett. 81, 2752 (2002).

[166] N. J. Watkins, Li Yan, and Yongli Gao, "Symmetry of Interfaces between Pentacene and Metals," Appl. Phys. Lett. 80, 4384 (2002).

[167] L. Yan and Y. Gao, "Interfaces in Organic Light-Emitting Diodes," Thin Solid Films 417, 101 (2002).

[168] Serkan Zorba, Quoc Toan Le, Neil J. Watkins, Li Yan, and Yongli Gao, "Morphology and Current-Voltage Measurement Studies of Pentacene by Atomic Force Microscopy," J. Nanosci. Nanotech. 1, 317 (2001).

[169] N. J. Watkins, Quoc Toan Le, S. Zorba, Li Yan, Yongli Gao, S. F. Nelson, C. S. Kuo, and T. N. Jackson, "Photoemission Characterization of Interfaces between Au and Pentacene," SPIE Proc. 4466, 1 (2001).

[170] Li Yan, N. J. Watkins, S, Zorba, Yongli Gao, and C. W. Tang, "Direct Observation of Fermi Level Pinning in Cs Doped CuPc Film," Appl. Phys. Lett. 79, 4148 (2001).

[171] Y. Nonogaki, Y. Gao, H. Mekaru, T. Miyamae, and T. Urisu, “STM observation of surface nanostructures on Si(111) formed after synchrotron radiation stimulated cleaning,” Transactions MRS Japan, 26, 751 (2001).

[172] Y. Nonogaki, Y. Gao, H. Mekaru, and T. Urisu, "Nanostructure Formation on Si(111) Surface Assisted by Synchrotron Radiation Illumination -Characterization by Scanning Tunneling Microscopy," J. Elec. Spec. Relat. Phen. 119, 241 (2001).

[173] Serkan Zorba, Q. Toan Le, Neil J. Watkins, Li Yan, and Yongli Gao, "Current-Voltage Measurements as a Function of Applied Tip Force on Pentacene by Conducting Probe Microscopy," MRS Proc. 660, JJ10.3 (2001).

[174] N.J. Watkins ,QuocToan Le, S. Zorba, Li Yan, and Yongli Gao, "Interface Formation in Pentacene Based Thin Film Transistors: an Electronic and Morphological Study," MRS Proc. 660, JJ7.3 (2001).

[175] Li Yan, Yongli Gao, M. G. Mason, and C.W. Tang, "Energy Level Alignment at Metal/Alq3 Interfaces Investigated by Photoemission Methods," MRS Proc. 660, JJ8.36 (2001).

[176] A.J. Mkinen, S. Schoemann, Yongli Gao, M.G. Mason, A.A. Muenter, and A.R. Melnyk, "Femtosecond Photoemission Study of Relaxation and Interface Charge Transfer Dynamics in Organic Photoreceptors," in Conjugated Polymer and Molecular Interfaces: Science and Technology for Photonic and Optoelectronic Applications, Ed. W.R. Salaneck, K. Seki, A. Kahn, and J. J. Pireaux (Marcel Dekker, New York, 2001).

[177] L. Yan, M.G. Mason, C.W. Tang, and Yongli Gao, "Energy Level Alignment in Metal/Organic Interfaces: Ca/Alq3 and Al/Alq3," SPIE Proc. 4105, 84 (2001).

[178] Li Yan, Yongli Gao, M.G. Mason, and C.W. Tang, "Photoemission Study of Energy Alignment at the Metal/Alq3 Interfaces," Appl. Surf. Sci. 175-176, 412 (2001).

[179] M.G. Mason, C.W. Tang, L,-S. Hung, P. Raychaudhuri, J. Madathil, D.J. Giesen, L. Yan, Q.T. Le, Y. Gao, S.-T. Lee, L.S. Liao, L.F. Cheng, W.R. Salaneck, D.A. dos Santos, and J.L. Brédas, "The Interaction of Tris-(8-hydroxyquinoline) aluminum with Reactive Metals and the Role of LiF," J. of Appl. Phys. 89, 2756 (2001).

[180] E.W. Forsythe and Y. Gao, “Interfaces in Organic Light Emitting Devices”, Book Chapter Review for “Handbook of Surfaces and Interfaces of Materials”, Ed. H.S. Nalwa, 286 (Academic Press, New York, 2001).

[181] A.J. Mkinen, S. Schoemann, Yongli Gao, M.G. Mason, A.A. Muenter, and A.R. Melnyk, "Femtosecond Photoemission Study of Excited State Dynamics in Organic Photoreceptors," SPIE Proc. 3940, 65, (2001).

[182] V.K. Gupta, M.W. Koch, N.J. Watkins, Y. Gao, G.W. Wicks, "Molecular Beam Epitaxial Growth of BGaAs Ternary Compounds," J. Elec. Mat. 29, 1387 (2000).

[183] F. Nuesch, E.W. Forsythe, Q.T. Le, Y. Gao, and L.J. Rothberg, “Importance of Indium Tin Oxide Surface Acido Basicity for Charge Injection into Organic Materials Based Light Emitting Diodes”, J. Appl. Phys., 87, 7973, (2000).

[184] N. Koch, R. Pairleitner, Q.T. Le, E.W. Forsythe, Y. Gao, and G. Leising, “Photoemission Spectroscopic Investigation on the Interface Formation of a Ladder-Type Poly(para-phenylene) with Aluminum”, Appl. Phys. Lett. 76, 3738, (2000).

[185] Y. Gao, H. Mekaru, T. Miyamae, and T. Urisu, "Scanning Tunneling Microscopy Study of Si(111) Surface Morphology after Removal of SiO2 by Synchrotron Radiation Illumination," Appl. Phys. Lett. 76, 1392 (2000).

[186] Q.T. Le, E.W. Forsythe, F. Nuesch, L. Rothberg, Li Yan, and Yongli Gao, "Interface Formation between NPB and Processed Indium-Tin-Oxide," Thin Solid Films, 363, 42 (2000).

[187] Q.T. Le, F. Nuesch, L.J. Rothberg, E.W. Forsythe, and Y. Gao, "Characterization of Treated Indium Tin Oxide Surface and Interface Formation with Phenyl Diamine,” SPIE Proc. 3797, 301 (2000).

[188] A.J. Makinen, S. Schoemann, Y. Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, A.R. Melnyk, and R.L. Headrick, "Femtosecond Excited State Dynamics in Organic Molecular Films," in Photoinduced Charge Transfer, Ed. L. Rothberg (World Scietific, New York, 2000).

[189] E.W. Forsythe, M. Abkowitz, C.W. Tang, and Yongli Gao, "Growth Modes and Hole Injection Characteristics of Organic Films on Induim Tin Oxide," in Photoinduced Charge Transfer, Ed. L. Rothberg (World Scietific, New York, 2000).

[190] Y. Gao, T. Miyamae, H. Mekaru, and T. Urisu, "Scanning Tunneling Microscopy Study of Surface Morphology of Si(111) after Synchrotron Radiation Stimulated Desorption of SiO2," J. of Vac. Sci. Tech., A18, 1153 (2000).

[191] E.W. Forsythe, M.A. Abkowitz, and Yongli Gao, “The Influence of Copper Phthalocynanine on the Charge Injection and Growth Modes for Organic Light Emitting Diodes,” J. of Vac. Sci. Tech., A18, 1869 (2000).

[192] E.W. Forsythe, M. Abkowitz, and Yongli Gao, “Tuning the Carrier Emission and Growth Modes,” J. of Phys. Chem. B104, 3948 (2000).

[193] Quoc Toan Le, Li Yan, Yongli Gao, M. G. Mason, D. J. Giesen, and C. W. Tang, "Photoemission Study of Al/tris-(8-hydroxyquinoline) Aluminum and Al/LiF/tris-(8-hydroxyquinoline) Aluminum Interfaces," J. Appl. Phys. 87, 375 (2000).

[194] A.J. Makinen, A.R. Melnyk, S. Schoemann, R.L. Headrick, and Yongli Gao, "Effect of Crystalline Domain Size on the Photophysical Properties of Thin Organic Molecular Films," Phys. Rev. B60, 14683 (1999).

[195] A.J. Makinen, S. Xu, Z. Zhang, S.J. Diol, Yongli Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, and A.R. Melnyk, "The Effect of Disorder on Excited State Dynamics in Organic Molecular Films," Appl. Phys. Lett. 74, 1296 (1999).

[196] E.W. Forsythe, V.-E. Choong, C.W. Tang, and Yongli Gao, "Interface Analysis of Naphthyl-Substituted Benzidine Derivative and Tris-8-(hydroxyquinoline) Aluminum Using Ultra-Violet and X-Ray Photoemission Spectroscopy,” J. Vac. Sci. Tech. A17, 3429 (1999).

[197] A.J. Makinen, S. Xu, Z. Zhang, S.J. Diol, Y. Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, and A.R. Melnyk, "Morphology and Excited State Dynamics in Thin Organic Molecular Films Probed by Femtosecond Time-Resolved Photoemission Spectroscopy," J. Vac. Sci. Tech. A17, 2329 (1999).

[198] E.W. Forsythe, Yongli Gao, L.G. Provost, and G.S. Tompa, “Photoemission Spectroscopy Analysis of ZnO:Ga Films for Display Applications,” J. Vac. Sci Tech. A17, 1761 (1999).

[199] Quoc Toan Le, F. M. Avendano, E. W. Forsythe, Li Yan, C. W. Tang, and Yongli Gao, "X-Ray Photoelectron Spectroscopy and Atomic Force Microscopy Investigation of Stability Mechanism of Tris-(8-hydroxyquinoline) Aluminum Based Light-Emitting Diodes," J. Vac. Sci. Tech. A17, 2314 (1999).

[200] F. Nuesch, L. J. Rothberg, E. W. Forsythe, Quoc Toan Le, and Yongli Gao, "A Photoelectron Spectroscopy Study on the Indium Tin Oxide Treatment by Acids and Bases," Appl. Phys. Lett. 74, 880 (1999).

[201] E.W. Forsythe, D.C. Morton, T.Q. Le, C.W. Tang, and Yongli Gao, "Energy Level Alignment and Trap States in Doped Tris-8-(hydroxyquinoline) Using Thermally Stimulated Luminescence," SPIE Proc. 3623, 13 (1999).

[202] Quoc Toan Le, M. G. Mason, Li Yan, V.-E. Choong, E. W. Forsythe, C. W. Tang, and Yongli Gao, "Interface Formation between Al and Ca with Tis-(8-hydroxyquinoline) Aluminum," SPIE Proc. 3623, 64 (1999).

[203] Quoc Toan Le, F. Nuesch, L. J. Rothberg, E. W. Forsythe, and Yongli Gao, "Photoemission Study of Phenyl-Diamine Treated Indium Tin Oxide Interface," Appl. Phys. Lett. 75, 1357 (1999).

[204] N.J. Watkins, G.W. Wicks, and Yongli Gao, "Oxidation study of GaN using x-ray photoemission spectroscopy," Appl. Phys. Lett. 75, 2602 (1999).

[205] F.M. Avendano, E.W. Forsythe, Yongli Gao, and C.W. Tang “The Growth Modes of NPB on Indium Tin Oxide,” Synth. Met. 102, 910 (1999).

[206] Quoc Toan Le, V.-E. Choong, M.G. Mason, C.W. Tang, and Yongli Gao, “Photoemission Study of Interfaces in Organic Light-Emitting Diodes,” Synth. Met. 102, 1014 (1999).

[207] S. Xu, S.J. Diol, A. Makinen, L. Rothberg, Yongli Gao, M.G. Mason, A.A. Muenter, D.A. Mantell, and R.J.D. Miller, “Super-Radiant Decay in Two-Dimensional Layered Semiconductors,” Ultrafast Phenomena XI, 292 (Springer-Verlag, Berlin, 1999).

[208] E.W. Forsythe, D.C. Morton, T.Q. Le, C.W. Tang, and Yongli Gao, “Trap States in Doped tris-8-(hydroxyquinoline) Using Thermally Stimulated Luminescence,” SPIE Proc. 3473, 23 (1999).

[209] Y. Gao, “Surface Analytical Studies of Interface Formation in Organic Light Emitting Devices,” Acc. Chem. Res. 32, 247 (1999).

[210] J. Cao, H.E. Elsayed-Ali, R.J.D. Miller, D.A. Mantell, and Y. Gao, “Femtosecond Photoemission Study of Ultrafast Electron Dynamics in Single Crystal Au(111) Films,” Phys. Rev. B58, 10948 (1998).

[211] C. Hochfilzer, G. Leising, Y. Gao, E. Forsythe, and C. W. Tang, "Emission Process in Bi-Layer Organic Light Emitting Devices," Appl. Phys. Lett., 73, 2254 (1998).

[212] E.W. Forsythe, D.C. Morton, C.W. Tang, and Yongli Gao, “Trap States of tris-8-(hydroxyquinoline) Aluminum and Naphthyl-Substituted Benzidine Derivative Using Thermally Stimulated Luminescence,” Appl. Phys. Lett. 73, 1457 (1998).

[213] Ioannidis, E.W. Forsythe, Yongli Gao, M.W. Wu, and E.M. Conwell, “Current-Voltage Characteristics of Organic Light Emitting Diodes,” Appl. Phys. Lett . 72, 3038 (1998).

[214] V.-E. Choong, M.G. Mason, C.W. Tang and Y. Gao, "Investigation of the Interface Formation Between Calcium and Tris-(8-hydroxy quinoline) aluminum," Appl. Phys. Lett. 72, 2689 (1998).

[215] V.-E. Choong, Y. Park, and Y. Gao, M.G. Mason, and C.W. Tang, "Photoluminesence Quenching of Alq3 by Metal Deposition: A Surface Analytical Investigation," J. Vac. Sci. Technol. A16, 1838 (1998).

[216] C. Hochfilzer, T. Jost, A. Niko, W. Graupner, G. Leising, C. W. Tang, E. Forsythe, Y. Gao, "Internal Field Distribution in Organic Light Emitting Devices With Double Layer Structure," Materials Research Society Symposium Proceedings 488, 121 (1998).

[217] E.W. Forsythe, D.C. Morton, C.W. Tang, and Y. Gao, "Trap States of Tris-8-(hydroxyquinoline) Aluminum and Naphthyl-Substituted Benzidine Derivative Using Thermally Stimulated Luminescence," Proceeding of Materials Research Society Symposium, Boston, in press.

[218] V.-E. Choong, Y. Park, Y. Gao, B.R. Hsieh, and C. W. Tang, "Luminescence of Organic Materials: Metal Induced Quenching and Its Revival," Proceeding of The Society for Imaging Science and Technology 50th Annual Conference, in press.

[219] Y. Gao, "Interface Formation in Polymeric Light Emitting Diodes: a Review of Modeling and Surface Analytical Measurements," in Polymer-Solid Interfaces: from Model to Real Systems, J.J. Pireaux, J. Delhalle, and P. Rudolf, Eds., 365 (PUN, Namur, Belgium, 1998).

[220] Y. Park, V. Choong, Y. Gao, B.R. Hsieh, C.W. Tang, "Interface Formation of PPV Oligomer with Ca: a Model System for Metal/Polymer Interface," in Polymer-Solid Interfaces: from Model to Real Systems, J.J. Pireaux, J. Delhalle, and P. Rudolf, Eds., 147 (PUN, Namur, Belgium, 1998).

[221] V. Choong, Y. Park, B.R. Hsieh, and Y. Gao, "Interface Formation in Organic Semiconductor Devices," in Electrical and Optical polymer Systems: Fundamentals, Methods, and Applications, edited by D. L. Wise, G. Wnek, D. J. Trantolo, and T. M. Cooper, (Marcel Dekker, New York, in press).

[222] W.C. Wan, Y. Gao, T.E. Goodwin, S.A. Gonzalez, W.A. Feld, and B.R. Hsieh, "PhenylatedPoly(p-phenylenevinylenes) Prepared via the Chlorine Precursor Route (CPR)," Macromolecular Symposia, 125, 205 (1998).

[223] B.R. Hsieh, W.C. Wan, Y. Yu, Y. Gao, T.E. Goodwin, S.A. Gonzalez, and W.A. Feld, "Synthesis of Highly PhenylatedPoly(p-phenylenevinylenes) via a Chlorine Precursor Route," Macromol. 31, 631 (1998).

[224] V.-E. Choong, Y. Park, Y. Gao, B.R. Hsieh, and C.W. Tang, "Metal Induced Photoluminescence Quenching of a PhenyleneVinylene Oligomer and Its Recovery," Macromolecular Symposia, 125, 83 (1998).

[225] H.G. Lee, S. Kim, C. Hwang, V. Choong, Y. Park, Y. Gao, and B.R. Hsieh, "A Study of Poly(p-phenylenevinylene) and its Derivatives Using X-ray Photoelectron Spectroscopy," J. Appl. Phys. 82, 4962 (1997).

[226] V.-E. Choong, Y. Park, B.R. Hsieh, C.W. Tang, and Y. Gao, "Effects of Metals on Luminescence of Organic Light Emitting Materials," Polymer Preprints 38, 392 (1997).

[227] V.-E. Choong, Y. Park, B.R. Hsieh, C.W. Tang, and Y. Gao, "Interfaces in Organic Light Emitting Devices: Quenching of luminescence," in Organic Light-Emitting Materials and Devices, Z.H. Kafafi, Ed., Procedings of SPIE Vol. 3148, 274 (1997).

[228] T.P. Nguyen, S. Lefrant, S. deVos, and Y. Gao, "Interfacial Reactions in Poly (phenylenevinylene)-Metal," Synth. Met. 84, 659 (1997).

[229] S. Xu, C.C. Miller, Y. Gao, D.A. Mantell, M.G. Mason, A.A. Muenter, B.A. Parkinson, and R.J.D. Miller, "Ultrafast Electron Dynamics in Two Dimensional Layered Systems: Two-Photon Photoemission Studies of SnS2," Chem. Phys. Lett. 272, 209 (1997).

[230] W.C. Wan, H. Antoniadis, V.-E. Choong, H. Razafitrimo, Y. Gao, W.A. Feld, and B.R. Hsieh, "Halogen Precursor Route to Poly(2,3-diphenyl-p-phenylene vinylene) (DP-PPV): Synthesis, Photoluminescence, Electroluminescence and Photoconductivity," Macromolecules 30, 6567 (1997).

[231] V. Choong, Y. Park, N, Shivaparan, C.W. Tang, and Y. Gao, "Deposition Induced Photoluminescence Quenching of Tris-(8-Hydroxyquinoline) Aluminum," Appl. Phys. Lett. 71, 1005 (1997).

[232] J. Cao, Y. Gao, R.J.D. Miller, H. Elsayed-Ali, and D.A. Mantell, "Femtosecond Photoemission Study of Ultrafast Electron Dynamics on Cu(100)," Phys. Rev. B56, 1099 (1997).

[233] Y. Park, V. Choong, B.R. Hsieh, C.W. Tang, and Y. Gao, "Gap-State Induced Photoluminescence Quenching of PhenyleneVinylene Oligomer and its Recovery by Oxidation," Phys. Rev. Lett. 78, 3955 (1997).

[234] V. Choong, Y. Park, B.R. Hsieh, and Y. Gao, "Radiation Induced Photoluminescence Quenching of PhenyleneVinylene Oligomer Thin Films," Phys. Rev. B55, 15460 (1997).

[235] S.A. Jenekhe, X. Zhang, X.L. Chen, V. Choong, J. Vitale, Y. Gao, and B.R. Hsieh, "Finite Size Effects on Electroluminescence of Nanoscale Semiconducting Polymer Heterojunctions," Chem. Mat. 9, 409 (1997).

[236] Y. Park, V. Choong, B.R. Hsieh, C.W. Tang, T. Wehrmeister, K. Mullen, and Y. Gao, "Electron Spectroscopy Studies of Interface Formation Between Metal Electrodes and Luminescent Organic Materials," J. Vac. Sci. Technol. A15, 2574 (1997).

[237] V. Choong, Y. Park, B.R. Hsieh, C.W. Tang, T. Wehrmeister, K. Mullen, and Y. Gao, "Effects of Metals on Luminescence of Organic Materials," J. Vac. Sci. Technol. A15, 1745 (1997).

[238] S. Xu, C.C. Miller, D.A. Mantell, R.J.D. Miller, and Y. Gao, "Time-Resolved Photoemission Spectroscopy Studies of Layered Compounds," J. Vac. Sci. Technol. A15, 1510 (1997).

[239] S. Diol, C.C. Miller, C.A. Schmuttenmaer, J. Cao, Y. Gao, D.A. Mantell, and R.J.D. Miller, "Photogenerated Hot Electron Dynamics at GaAs(100) Surfaces," J. Phys. D30, 1427 (1997).

[240] V. Choong, Y. Park, Y. Gao, and B.R. Hsieh, "Quantum Molecular Quantum Mechanical Calculations of the Interface Formation between Al, Ca and Mg with Poly(PhenyleneVinylene) (PPV) Oligomers," J. Phys. D30, 1421 (1997).

[241] C.C. Miller, S. Diol, C.A. Schmuttenmaer, J. Cao, D.A. Mantell, R.J.D. Miller, and Y. Gao, "Reverse surface photovoltaic effects in GaAs surface quantum wells," J. Phys. D30, 1416 (1997).

[242] E. Ettedgui, B.R. Hsieh, and Y. Gao, "Interface Formation of Metals and Poly(p-PhenyleneVinylene): Surface Species and Band Bending," Polym. Adv. Technol. 8, 408 (1997).

[243] E. Ettedgui, H. Razafitrimo, B.R. Hsieh, W.A. Feld, M.W. Ruckman, and Y. Gao, "Near Edge X-ray Absorption Fine Structure Study of Poly(2,3-diphenylphenylene vinylene) Following the Deposition of Metal," in Photonics and Optoeletronics Polymers, edited by S.A. Jenekhe and K.J. Wynne, 408 (Am. Chem. Soc., Washington, DC. 1997).

[244] L.H. Guo, G.L. McLendon, H. Razafitrimo, and Y. Gao, "Photo-active and Electro-active Protein Films Prepared by Reconstitution with Metalloporphyrins Self-assembled on Gold," J. Mater. Chem. 6, 369-374 (1996).

[245] H. Razafitrimo, B.R. Hsieh, and Y. Gao, "Imaging Surfaces of Thin Conjugated Polymer Films by Scanning Tunneling Microscope," Proceedings of Third Workshop on Industrial Applications of Scanned Probe Microscopy, Gaithersburg (1996).

[246] B.R. Hsieh, V. Choong, H. Razafitrimo, Y. Gao, H. Antoniadis, D. Roitman, and W.A. Feld, "Light Emitting Diodes Based on Poly(p-phenylenevinylene)," Proceeding of The Society for Imaging Science and Technology 49th Annual Conference, 401 (1996).

[247] V. Choong, Y. Park, B.R. Hsieh, C.W. Tang, T. Wehrmeister, K. Mullen, and Y. Gao, "Severe Photoluminescence Quenching of 1,4-bis[4-(3,5-di-tert-butylstyry)styryl]benzene upon Deposition of Submonolayer Ca," Polym. Preprints 37(2), 583 (1996).

[248] H. Razafitrimo, B.R. Hsieh, T. Wehrmeister, K. Mullen, and Y. Gao, "Comparative Topographic Study of Differently Prepared Conjugated Polymer and Oligomer Films Using Scanning Tunneling Microscope," Polym. Preprints, 37(2), 581 (1996).

[249] B.R. Hsieh, V. Choong, H. Razafitrimo, Y. Gao, H. Antoniadis, D. Roitman, W. A. Feld, "Light-Emitting Diodes Based on Poly(p-phenylenevinylenes)", Polym. Mater. Sci. Eng., 75, 323 (1996).

[250] V. Choong, Y. Park, Y. Gao, T. Wehrmeister, K. Müllen, B.R. Hsieh, and C. W. Tang, "Dramatic Photoluminescence Quenching of PhenyleneVinylene Oligomer Thin Films upon Submonolayer Ca Deposition," Appl. Phys. Lett. 69, 1492 (1996).

[251] Y. Park, E. Ettedgui, V. Choong, Y. Gao, B.R. Hsieh, T. Wehrmeister, and K. Mullen, "Energy Level Bending and Alignment at the Interface between Ca and a PhenyleneVinylene Oligomer," Appl. Phys. Lett. 69, 1080 (1996).

[252] Y. Park, V. Choong, Y. Gao, B.R. Hsieh, and C.W. Tang, "Work Function of Indium Tin Oxide Transparent Conductor Measured by Photoelectron Spectroscopy," Appl. Phys. Lett. 68, 2699 (1996).

[253] H. Razafitrimo, Y. Gao, and B.R. Hsieh, "A Layer-wise Topographic Study of a Polymeric Light Emitting Diode: Indium Tin Oxide/Poly(diphenyl phenylenevinylene)/Ag," Synth. Met. 79, 103 (1996)

[254] B.R. Hsieh, E. Ettedgui, K.T. Park, and Y. Gao, "The Surface Species of Poly(p-phenylenevinylene) and Their Effects on the Metal Interface Formation," Synth. Met. 78, 269 (1996)

[255] E. Ettedgui, H. Razafitrimo, Y. Gao, and B.R. Hsieh, "Schottky Barrier Formation at the Ca/Poly(p-phenylenevinylene) Interface and its Role in Tunneling at the Interface," Synth. Met. 78, 247 (1996).

[256] C.A. Schmuttenmaer, C.C. Miller, J.W. Herman, J. Cao, D.A. Mantell, Y. Gao, and R.J.D. Miller, "Femtosecond Time-Resolved Photoemission Study of Hot Electron Relaxation at the GaAs(100) Surface," Chem. Phys. 205, 91 (1996).

[257] M.R. Robinson, H. Razafitrimo, Y. Gao, and B.R. Hsieh, "The Aging Behaviors of a Sulfonium Precursor Polymer of Poly(p-phenylenevinylene)," Polym. Mater. Sci. Eng. 74, 292 (1996).

[258] S. Xu, J. Cao, C. Miller, D.A. Mantell, R.J.D. Miller, and Y. Gao, "Energy Dependence of Electron Lifetime in Graphite Observed with Femtosecond Photoemission Spectroscopy," Phys. Rev. Lett. 76, 483 (1996).

[259] E. Ettedgui, H. Razafitrimo, Y. Gao, B.R. Hsieh, W.A. Feld, and M.W. Ruckman, "Evidence for the Formation of Unoccupied States in Poly(2,3-diphenyl phenylenevinylene) Following the Deposition of Metal," Phys. Rev. Lett. 76, 299 (1996).

[260] M.A. Aeschlimann, E. Hull, C.A. Schmuttenmaer, J. Cao, Y. Gao, D.A. Mantell, and H.E. Elsayed-Ali, "Time-Resolved Electron Diffraction to Study Photoinduced Molecular Dynamics at Single Crystal Surfaces," Proc. SPIE 2521, 103 (1996).

[261] H. Razafitrimo, K. T. Park, E. Ettedgui, Y. Gao, and B. R. Hsieh, "Interface Formation of Ca with Poly(P-PhenyleneAlpha,Alpha'-Diphenyl Vinylene) and Poly(P-Phenylene Alpha-Phenylvinylene)." Polymer International 36, 147-153 (1995).

[262] Y. Park, E. Ettedgui, Y. Gao, B.R. Hsieh, K. Mullen, "Modeling Band Bending at Metal/PPV Interface Using a PhenyleneVinylene Oligomer," Polym. Preprints, 36(2), 382 (1995).

[263] B.R. Hsieh, H. Razafitrimo, Y. Gao, W. A. Feld, "Highly PhenylatePoly(p-phenylenevinylenes) (HP-PPVs) via The Chlorine Precursor Route," Polym. Preprints, 36(2), 85 (1995).

[264] B.R. Hsieh, H. Razafitrimo, Y. Gao, W. A. Feld, "Highly PhenylatedPoly(p-phenylenevinylenes) (HP-PPVs) via The Chlorine Precursor Route (CPR): On the Photophysical Properties," Polym. Mater. Sci. Eng. 73, 557 (1995).

[265] E. Ettedgui, H. Razafitrimo, Y. Gao, and B.R. Hsieh, "Band Bending Modified Tunneling at Metal/Conjugated Polymer Interfaces," Appl. Phys. Lett. 67, 2705 (1995).

[266] H. Razafitrimo, E. Ettedgui, L.H. Guo, G.L. McLendon, and Y. Gao, "X-Ray Photoemission Study of the Interface Formation between Ca and Self-Assembled Thiol Monolayers," Appl. Phys. Lett. 67, 2621 (1995).

[267] S.P. Duggagupta, L. Tsybeskov, P.M. Fauchet, E. Ettedgui, and Y. Gao, "Post-Anodization Implantation and CVD Techniques for Passibation of Porous Silicon," Microcrytals and Nanocryatalline Semiconductors, Mat. Res. Soc. Symp. Proc. 358, 381 (1995).

[268] P.M. Fauchet, C. Peng, L. Tsybeskov, Ju.V. Vandyshev, A. Dubois, L. McLoud, S.P. Duttagupta, J.M. Rehm, G.L. Mclendon, E. Ettedgui, Y. Gao, F. Seiferth, S.K. Kurinec, A. Raisanen, T.E. Orlowski, L.J. Brillson, and G.E. Carver, "Prospects for Light-Emitting Diodes Made of Porous Silicon from Blue to beyond 1.5 m," Proc. SPIE 2144, 98 (1995).

[269] M.A. Aeschlimann, C.A. Schmuttenmaer, J. Cao, Y. Gao, H.E. Elsayed-Ali, R.J.D. Miller, and D.A. Mantell, "Observation of Surface Enhanced Multiphoton Photoemission from Metal Surfaces in the Short Pulse Limit," J. Chem. Phys. 102, 8606 (1995).

[270] E. Ettedgui, J. Cao, Ken T. Park, Y. Gao, and M.W. Ruckman, "Photo-assisted Oxidation of GaAs(100) with Condensed Water Using Synchrotron Photoemission Spectroscopy," J. Appl. Phys. 77, 5411 (1995).

[271] Ken T. Park, Jianming Cao, E. Ettedgui, Y. Gao, and M.W. Ruckman, "Investigation of thin Cr Overlayer in Cr/NH3/GaAs(100) Using Synchrotron Radiation," J. Vac. Sci. Technol. A13, 200 (1995).

[272] M.A. Aeschlimann, E. Hull, J. Cao, C.A. Schmuttenmaer, L.G. Jahn, Y. Gao, H.E. Elsayed-Ali, D.A. Mantell, and M.R. Scheinfein, "A Picosecond Electron Gun for Surface Analysis," Rev. Nucl. Instrum. 66, 1000 (1995).

[273] E. Ettedgui, H. Razafitrimo, K.T. Park, Y. Gao, and B.R. Hsieh, "X-ray Photoemission Spectroscopy Study of Band Bending at the Interface of Metal with Poly(p-phenylenevinylene)," Surf. Interface Anal. 23, 89 (1995).

[274] H. Razafitrimo, K.T. Park, E. Ettedgui, Y. Gao, and B.R. Hsieh, "Interface Formation of Ca with Poly(p-phenylenevinylene)-Di-Phenyl and Poly(p-phenylenevinylene)-Phenyl," Polym. International 36, 147 (1995).

[275] C.A. Schmuttenmaer, M. Aeschlimann, J. Cao, Y. Gao, D.A. Mantell, and R.J.D. Miller, "Femtosecond Photoemission Studies of Electron Relaxation at Cu Surfaces," Ultrafast Phenomena IX, A.H. Zewail, G. Mourou, W. Knox, and P.F. Barbara, Eds., 307 (Springer-Verlag, Berlin, 1994).

[276] B.R. Hsieh, E. Ettedgui, K.T. Park, and Y. Gao, "The Surface Species of Poly(p-Phenylene-Vinylene) and Their Effects on Calcium Interface Formation," Mol. Cryst. Liq. Cryst. 256, 71 (1994).

[277] C.A. Schmuttenmaer, M.A. Aeschlimann, J. Cao, H.E. Elsayed-Ali, R.J.D. Miller, D.A. Mantell, and Y. Gao, "Femtosecond Studies of Carrier Relaxation Processes at Single Crystal Metal Surfaces," Proc. SPIE 2125, 98 (1994).

[278] C.A. Schmuttenmaer, M.A. Aeschlimann, J. Cao, H.E. Elsayed-Ali, R.J.D. Miller, D.A. Mantell, and Y. Gao, "Time Resolved Two Photon Photoemission from Cu(100): Energy Dependence of Electron Relaxation," Phys. Rev. B 50, Rapid Comm., 8957 (1994).

[279] P.M. Fauchet, C. Peng, L. Tsybeskov, J. Vandyshev, A. Dubois, A. Raisanen, T.E. Orlowski, L.J. Brillson, J.E. Fouquet, S.L. Dexheimer, J.M. Rehm, G.L. Mclendon, E. Ettedgui, Y. Gao, F. Seiferth, and S.K. Kurinec, "Intense Room Temperature Light Emission in Porous Silicon: from Less than 450 nm to beyond 1.5 m," in Advanced Photonics Materials for Information Technology, edited by S. Etemad, 34 (SPIE, 1994).

[280] E. Ettedgui, H. Razafitrimo, K.T. Park, Y. Gao, and B.R. Hsieh, "An XPS Study of Sample Preparation on Band Bending at the Interface of Al with Poly(p-phenylenevinylene)," J. Appl. Phys. 75, 7526 (1994).

[281] E.A. Murphy, H.E. Elsayed-Ali, Ken T. Park, and Y. Gao, "Temperature-Dependent X-ray Photoelectron Diffraction of Pb(100): Experimental Results and the Single-Scattering Cluster Model," J. Vac. Sci. Technol. A11, 3106 (1993).

[282] L. Tsybeskov, C. Peng, S.P. Duttagupta, E. Ettedgui, Y. Gao, P.M. Fauchet, and G.E. Carver, "Comparative Study of Light-Emitting Porous Silicon Anodized with Light Assistance and in the Dark," Mat. Res. Soc. Symp. Proc. 298, 271 (1993).

[283] P.M. Fauchet, E. Ettedgui, A. Raisanen, L.J. Brillson, F. Seiferth, S.K. Kurinec, Y. Gao, C. Peng, and L. Tsybeskov, "Can Oxidation and Other Treatments Help Us Understand the Nature of Light-Emitting Porous Silicon?" Mat. Res. Soc. Symp. Proc. 298, 307 (1993).

[284] Y. Gao, Ken T. Park, and B.R Hsieh, "Interface Formation of Ca with Poly(p-phenylenevinylene)," J. Appl. Phys. 73, 7894 (1993).

[285] Bing R. Hsieh, Y. Gao, and Ken T. Park, "Characteristics of Metal-Poly(phenylenevinylene) Interfaces," in Electroluminescent Materials, Devices, and Large-Screen Displays, edited by E.M. Conwell, M. Stolka, and M.R. Miller, 195 (International Society for Optical Engineering, 1993).

[286] E. Ettedgui, C. Peng, L. Tsybeskov, Y. Gao, P.M. Fauchet, H.A. Mizes, and G.E. Carver, "High Spatial Resolution Mapping of Porous Silicon," in Microcrystalline Semiconductor: Material Science and Devices, edited by P.M. Fauchet, C.C. Tsai, L.T. Canham, I. Shimizu, and Y. Aouagi, 173 (Materials Research Society, Pittsburgh, 1993).

[287] E. Ettedgui, Ken T. Park, Jianming Cao, Y. Gao, and M.W. Ruckman, "Growth of a Cr Oxide Layer on GaAs(100) by Oxidation with Condensed Water," J. Appl. Phys. 73, 1781 (1993).

[288] Ken T. Park and Y. Gao, "Cryogenic Growth of Al Nitride Layers on GaAs(110): X-ray Photoemission and Inverse Photoemission Spectroscopy Studies," Phys. Rev. B 47, 4491 (1993).

[289] Y. Gao, Ken T. Park, and B.R. Hsieh, "X-ray Photoemission Investigations of the Interface Formation of Ca and Poly(p-phenylenevinylene)," J. Chem. Phys. 97, 6991 (1992).

[290] Y. Gao and Ken T. Park, "Medium Energy Electron Diffraction from Cu(100)," Phys. Rev. B 46, 1743 (1992).

[291] T. Balasubramanian, Jianming Cao, and Y. Gao, "X-ray Photoemission Spectroscopy Studies of Cesium and Oxygen on GaAs(100)," J. Vac. Sci. Technol. A 10, 3158 (1992).

[292] N. Li, Z. D. Lin, Y. Gao, and J. H. Weaver, "SYNCHROTRON RADIATION PHOTOEMISSION-STUDIES ON THE PALLADIUM COMPOUND SEMICONDUCTOR INTERFACES - VALENCE BAND STUDIES." Vacuum 43, 587-590 (1992).

[293] N. Li, Z. D. Lin, Y. Gao, and J. H. Weaver, "VALENCE BAND STUDIES ON Pd/COMPOUND SEMICONDUCTOR INTERFACES." Chinese Physics 11, 987-997 (1991).

[294] Ken T. Park, Jianming Cao, Y. Gao, G.W. Wicks, and M.W. Ruckman, "Growth of Al Nitride Layers on GaAs(100) by Reaction with Condensed Ammonia," J. Appl. Phys. 70, 2623 (1991).

[295] M.W. Ruckman, M. Strongin, Jianming Cao, Ken T. Park, Y. Gao, and G.W. Wicks, "White Beam Synchrotron Radiation Degradation of GaAs(100)," Appl. Phys. Lett. 59, 849 (1991).

[296] E.A. Murphy, H.E. Elsayed-Ali, Ken T. Park, Jianming Cao, and Y. Gao, "Angle Resolved X-ray Photoemission Study of the Surface Disordering of Pb(100)," Phys. Rev. B 43, 12615 (1991).

[297] A. Wall, Y. Gao, A. Raisanen, A. Franciosi, and J.R. Chelicowsky, "Electron Density of States of CdTe," Phys. Rev. B 43, 4988 (1991).

[298] Y. Gao and Jianming Cao, "Incident Beam Effects in Electron-stimulated Auger Electron Diffraction," Phys. Rev. B 43, 9692 (1991).

[299] Y. Gao, C.P. Lusignan, M.W. Ruckman, and M. Strongin, "Growth of Al Oxide Layers on GaAs(100) by Reaction with Condensed Molecular Oxygen," J. Appl. Phys. 67, 7148 (1990).

[300] A. Franciosi, A. Wall, Y. Gao, J.H. Weaver, M. H. Tsai, J.D. Dow, R.V. Kasowski, R. Reifenberger, and F. Pool, "d-states, Exchange Splitting, and Mn Electronic Configuration in Cd1-xMnxTe,'' Phys. Rev. B 40, Rapid Comm., 12009 (1989).

[301] G.D. Waddill, C.M. Aldao, I.M. Vitomirov, Y. Gao, and J.H. Weaver, "Temperature Effects on Schottky Barrier Formation for Au/InP(110)," J. Vac. Sci. Technol. A 7, 865 (1989).

[302] Y. Hu, T.J. Wagener, Y. Gao, and J.H. Weaver, "Empty Electronic State Evolution for Sc and Electron Dynamics at the 3p-3d Giant Dipole Resonance," Phys. Rev. B 39, 8162 (1989).

[303] T.J. Wagener, Y. Hu, Y. Gao, M.B. Jost, J.H. Weaver, N.D. Spencer, and K.C. Goretta, "Resonance Inverse Photoemission of Bi2Ca1+xSr2-xCu2O8+y and YBa2Cu3O7-x, Unoccupied Oxygen States, and Plasmons," Phys. Rev. B 39, 2928 (1989).

[304] A. Wall, A. Franciosi, Y. Gao, J.H. Weaver, M.-H. Tsai, J.D. Dow, and R.V. Kasowski, "Inverse Photoemission and Resonant Photoemission Characterization of Semimagnetic Semiconductors," J. Vac. Sci. Technol.A 7, 656 (1989).

[305] B.M. Trafas, I.M. Vitomirov, C.M. Aldao, Y. Gao, F. Xu, J.H. Weaver, and D.L. Panins, "Cr, Co, Pd, Au, and In Overlayers on PbS(100) Surfaces: Adatom Interactions and Interface Formation," Phys. Rev. B 39, 3265 (1989).

[306] Y. Hu, T.J. Wagener, Y. Gao, and J.H. Weaver, "Resonant Inverse Photoemission Involving Transition-metal Subshell Interactions," Phys. Rev. B 38, Rapid Comm. 12708 (1988).

[307] I.M. Vitomirov, C.M. Aldao, Zhangda Lin, Y. Gao, B.M. Trafas and J.H. Weaver, "PdOverlayer Growth on InP(110), GaAs(110), and InSb(110): Comparisons of Anion Surface Segregation," Phys. Rev. B 38, 10776 (1988).

[308] H.M. Meyer III, D.M. Hill, T.J. Wagener, Y. Gao, J.H. Weaver, D.W. Capone II, and K.C. Goretta, "Electronic Structures for the YBa2Cu3O6.9 Surface and its Modification by Sputtering and Adatoms of Ti and Cu," Phys. Rev. B 38, 6500 (1988).

[309] A. Franciosi, A. Wall, Y. Gao, J.H. Weaver, S. Chang, A. Raisanen, and B. Rehil, "Inverse Photoemission Studies of Ternary Semimagnetic Semiconductors: Where Have All the d-states Gone?" in Proc. 19th Int. Conf. on the Phys. of Semiconductors, edited by W. Zawaolzki and J.M. Langer, (DHN Limited, Warsaw, Poland, 1988).

[310] J.H. Weaver, H.M. Meyer III, T.J. Wagener, D.M. Hill, Y.Gao, D. Peterson, Z. Fisk, and A.J. Arko, "Valence Bands, Oxygen in Planes and Chains, and Surface Changes for Single Crystals of M2CuO4 and MBa2Cu3Ox (M=Pr, Nd, Eu, Gd)," Phys. Rev. B 38, 4668 (1988).

[311] T.J. Wagener, Y. Gao, I.M. Vitomirov, C.M. Aldao, J.J. Joyce, J.H. Weaver, and C. Capone II, "Disruption, Segregation and Passivation for the Interfaces of Pd and Noble Metal Overlayers on YBa2Cu3O6.9," Phys. Rev. B 38, 232 (1988).

[312] Y. Hu, T.J. Wagener, Y. Gao, and J.H. Weaver, "Empty Electronic States of Graphite and the Growth of Au and Pd Clusters," Phys. Rev. B 38, 3037 (1988).

[313] Y. Gao, T.J. Wagener, C.M. Aldao, I.M. Vitomirov, J.H. Weaver, and D.W. Capone II, "Photoemission and Inverse Photoemission Studies of La Adatom Interactions with YBa2Cu3O6.9," J. Appl. Phys. 64, 1296 (1988).

[314] T.J. Wagener, Y. Gao, H.M. Meyer III, D.M. Hill, S.G. Anderson, and J.H. Weaver "Spectroscopic Examinations of the Surface Stability of High Temperature Superconductors," in Thick Film Processing and Characterization of High Temperature Superconductors, edited by J.M. Happer, R.J. Cotton, and L.C. Feldman, 368 (AIP proceedings of AVS Topical Conference on Thin Film Processing and Characterization of High-Temperature Superconductors, New York, 1988).

[315] H.M. Meyer III, Y. Gao, T.J. Wagener, D.M. Hill, S.G. Anderson, and J.H. Weaver, "High Temperature Superconductors: Occupied and Unoccupied Electronic States," in Thick Film Processing and Characterization of High Temperature Superconductors, edited by J.M. Happer, R.J. Cotton, and L.C. Feldman, 254 (AIP proceedings of AVS Topical Conference on Thin Film Processing and Characterization of High-Temperature Superconductors, New York, 1988).

[316] Y Gao, H.M. Meyer III, T.J. Wagener, D.M. Hill, S.G. Anderson, and J.H. Weaver "Interface Formation: High Temperature Superconductors with Noble Metals, Reactive Transition Metals, and Semiconductors," in Thick Film Processing and Characterization of High Temperature Superconductors, edited by J.M. Happer, R.J. Cotton, and L.C. Feldman, 358 (AIP proceedings of AVS Topical Conference on Thin Film Processing and Characterization of High-Temperature Superconductors, New York, 1988).

[317] Y. Gao, I.M. Vitomirov, C.M. Aldao, T.J. Wagener, J.J. Joyce, C. Capasso, J.H. Weaver, and D.W. Capone II, "Synchrotron Radiation Photoemission Studies of the Interface Formation between Metals and High Tc Superconductors: Al and In on YBa2Cu3O6.9," Phys. Rev. B 37, Rapid Comm., 3741 (1988).

[318] B. Smandek, Y. Gao, T.J. Wagener, J.H. Weaver, F. Levy, and G. Margaritondo, "Bremsstrahlung Isochromat Study of the Layered Compounds InSe, TiSe2, SnSe2, SnS2, and Bi2Te3," Phys. Rev. B 37, 4196 (1988).

[319] Y. Gao, T.J. Wagener, J.H. Weaver, and D.W. Capone II, "Interface Formation of Semiconductors with High Tc Superconductors: Ge/La1.85Sr0.15CuO4," Phys. Rev. B 37, 515 (1988).

[320] D.M. Hill, Y. Gao, H.M. Meyer III, T.J. Wagener, J.H. Weaver, and D.W. Capone II, "Cu-Induced Surface Disruption of La1.85Sr0.15CuO4," Phys. Rev. B 37, 511 (1988).

[321] Y. Gao, M. Grioni, B. Smandek, and J.H. Weaver, and T. Tyrie, "Inverse Photoemission Spectrometer for Interface Studies," J. Phys. E 21, 489 (1988).

[322] Y. Gao, B. Smandek, M. Nikaido, J.H. Weaver, F. Levy, and G. Margaritondo, "Bremsstrahlung Isochromat Spectroscopy Studies of Conduction Band States in GaSe," Solid State Comm. 65, 11 (1988).

[323] H.M. Meyer III, T.J. Wagener, D.M. Hill, Y. Gao, S.G. Anderson, S.D. Krahn, J.H. Weaver, B. Flandermeyer, and D.W. Capone II, "Spectroscopic Evidence for Passivation of the La1.85Sr0.15CuO4 Surface with Gold," Applied Phys. Lett. 51, 1118 (1987).

[324] Y. Gao, T.J. Wagener, J.H. Weaver, B. Flandermeyer, and D.W. Capone II, "Reaction and Intermixing at Metal-Superconductor Interfaces: Fe/YBa2Cu3O6.9," Applied Phys. Lett. 51, 1032 (1987).

[325] T.J. Wagener, Y. Gao, J.H. Weaver, A.J. Arko, B. Flandermeyer, and D.W. Capone II, "Unoccupied Electronic States and Surface Phenomena for YBa2Cu3O6.9," Phys. Rev. B 36, 3899 (1987).

[326] J.H. Weaver, Y. Gao, T.J. Wagener, B. Flandermeyer, and D.W. Capone II, "Reaction and Disruption for Fe/La1.85Sr0.15CuO4: Interface Formation for High Temperature Superconductors," Phys. Rev B 36, Rapid Comm., 3975 (1987).

[327] Y. Gao, T.J. Wagener, J.H. Weaver, A.J. Arko, B. Flandermeyer, and D.W. Capone II, "Inverse Photoemission Studies of the Empty Electronic States and Surface Stability of La1.85Sr0.15CuO4," Phys. Rev. B 36, Rapid Comm., 3971(1987).

[328] Y. Gao, T.J. Wagener, D.M. Hill, H.M. Meyer III, J.H. Weaver, A.J. Arko, B. Flandermeyer, and D.W. Capone II, "High-Temperature Superconductors: Occupied and Unoccupied Electronic States, Surface Stability, and Interface Formation" in Chemistry of High-Temperature Superconductors, edited by D.L. Nelson, M.S. Whittingham, and T.F. George, 212 (American Chemical Society, Washington DC, 1987).

[329] Y. Gao, B. Smandek, T.J. Wagener, J.H. Weaver, F. Levy, and G. Margaritondo, "Bremsstrahlung Isochromat Studies of Conduction Band States in SnS2 and SnSe2," Phys. Rev. B 35, Rapid Comm., 9357 (1987).

[330] Y. Gao and R. Reifenberger, "Yield of Photofield Emitted Electrons from Tungsten," Phys. Rev. B 35, 8301(1987).

[331] Y. Gao and R. Reifenberger, "Band Structure Effects in Photofield Emission," Phys. Rev. B 35, 6627 (1987).

[332] Y. Gao and Reifenberger, "Photofield Emission from Transition Metal Surface States," Phys. Rev. B 35, 4284 (1987).

[333] Y. Gao and R. Reifenberger, "Field Emission Energy Distribution Study of Laser Induced Thermal Effects on Metal Surfaces," J. Vac. Sci. Technol. A 4, 1289 (1986).

[334] Y. Gao and R. Reifenberger, "Energy Resolved Photofield Emission from the W(100) Surface State," Phys. Rev. B 32, Rapid Comm., 1380 (1985).

[335] Y. Gao and R. Reifenberger, "A Design Innovation for the 127° Differential Electron Energy Analyzer," J. Phys. E 18, 381(1985).

[336] Y. Gao, K.V. Devi-Prased, and E.W. Prohofsky, "A Self-Consistent Microscopic Theory of Hydrogen Bond Melting with Application to poly(dG)*poly(dC)," J. Chem. Phys. 80, 6291 (1984).

[337] Y. Gao and E.W. Prohofsky, "A Modified Self-Consistent Phonon Theory of Hydrogen Bond Melting," J. Chem. Phys. 80, 2242 (1984).

[338] W.K. Lee, Y. Gao, and E.W. Prohofsky, "Structure of Hydrated Na ions around a Region of A- or B-DNA Helix," Biopolymers 23, 257 (1984).


2. 邀请报告


[1] “Light and Environmental Factors on Trihalide Perovskite Materials,” Nature-Light Conference, Changchun, July 2016.

[2] “Manipulation of electronic structure by metal oxide in organic optoelectronic device,” Bi-Annual Meeting of Chemical Society of China, Dalian, June 2016.

[3] “Interface Formation and Surface Degradation of Trihalide Perovskite,” International Conf. Syn. Metal, Guangzhou, June 2016.

[4] “Interface Formation and Surface Degradation of Trihalide Perovskite Materials,” Collaborative Conference on Materials Research (CCMR), Jeju, South Korea, June 2016.

[5] “Stability and Interfaces in Organo-Metallic Perovskite Solar Cell Materials,” EMN Summer Meeting, Qingdao, June 2016.

[6] “Application of Metal Oxide in Organic Semiconductors,” Organic Semiconductor Workshop, Changsha, China, April 2016.

[7] “Degradation of Co-evaporated Perovskite Thin Films and Metal Oxide Insertion Layers in Organic Semiconductors,” Organic Optoelectronics Workshop II, Hengyang, China, August 2015.

[8] “Doping of Organic Semiconductor with Metal Oxide,” 4th Annual World Congress of Advanced Materials (WCAM), Chongqing, China, May 2015.

[9] “Degradation of Co-evaporated Perovskite Thin Films,” Advanced Solar Cell Workshop, Beijing, May 2015.

[10] “The Role of Molybdenum Oxide for Organic Electronics: Surface Analytical Studies,” 2nd International Symposium on Energy Challenges and Mechanics, Aberdeen, England, August 2014.

[11] “Surface Analytical Investigation on Organometal Triiodide Perovskite,” SPIE Symposium, San Diego, Aug. 2014.

[12] “The Role of Molybdenum Oxide for Organic Electronics: Surface Analytical Studies,” Collaborative Conference on Materials Research (CCMR), Jeju, South Korea, June 2014.

[13] “Electronic Structure Investigation of Doping C60 with Metal Oxide by Bulk Doping and Ultra-thin layer Doping,” EMN Summer Meeting, Cancun, Mexico, June 2014.

[14] “Surface Analytical Investigation on Organometal Triiodide Perovskite,” 3rd Annual World Congress of Advanced Materials (WCAM), Chongqing, China, June 2014.

[15] “Investigation of Doping C60 with Metal Oxide,” National Conference on Organic Light Emitting Properties-VII, Changchun, China, July 2013.

[16] “Investigation of Doping C60 with Metal Oxide,” POEM 2013, Wuhan, China, May 2013.

[17] “Mechanisms of improved charge transfer by thin metal oxide films,” MRS Spring Meeting, San Jose, April 2013.

[18] “Mechanisms of improved charge transfer by thin metal oxide films,” EMN Fall Meeting, Las Vegas, Dec. 2012.

[19] “Methods to Protect and recover work function of air exposed transition metal oxide thin films,” SPIE Symposium, San Diego, Aug. 2012.

[20] “Metal-Oxides Hole Injection Layer in Organic Semiconductor Devices,” Tri-University Research Workshop on Advanced Engineering, Wuhan, China, Nov. 2011.

[21] “Metal-Oxides Hole Injection Layer in Organic Semiconductor Devices,” National Conference on Organic Light Emitting Properties-VII, Zhangjiajie, China, Oct. 2011.

[22] “Metal-Oxides Hole Injection Layer in Organic Semiconductor Devices,” Structure and Processes at Molecular-based Interfaces Conference-VI, Karlsruhe, Germany, Sept. 2011.

[23] “How to Make ITO a Better Anode,” SPIE Symposium, San Diego, Aug. 2011.

[24] “Spin Injection in Organic Semiconductors,” Summer Symposium of Hunan Physical Society, Loudi, China, July 2011.

[25] “Angle resolved photoemission study of rubrene single crystal,” 219th ECS Meeting, Montreal, Canada, April 2011.

[26] “Debye Screening in Organic Thin Film Transistors,” Hunan Physical Society Meeting, Xiangtan, China, Jan. 2011.

[27] “Rubrene Electronic Structure, Interface Energy Level Alignment, and Growth Dynamics,” SPIE Symposium, San Diego, Aug. 2010.

[28] “Oxide Insertion Layer in Organic Semiconductor Devices,” SPIE Symposium, San Diego, Aug. 2010.

[29] “Metal Oxide Insertion Layer in Organic Semiconductor Device,” International Workshop on Organic Electronics and Spintronics, Nagoya, Japan, March 2010.

[30] “Insertion and Debye Screening in Organic Semiconductor Interfaces,” Electronic Structure and Processes at Molecular-based Interfaces Conference-V, Chiba, Japan, January 2010.

[31] “Interface study of insertion layers in organic semiconductor devices,” SPIE Symposium, San Diego, Aug. 2009.

[32] “Electronic Structure of Doping in Organic Semiconductor,” SPIE Symposium, San Diego, Aug. 2008.

[33] “Modification on the Electronic Structure of Organic Semiconductors by Alkali Metal,” 212th ECS Meeting, Washington DC, Sept. 2007.

[34] “Interface Studies on Organic Semiconductors,” ARO Organic/inorganic/flexible Electronics Workshop, Phoenix, Dec. 2006.

[35] “Alkali Metal Doping and Energy Level Shift in Organic Semiconductors,” The 6th International Conference on Electroluminescence of Molecular Materials and Related Phenomena, Hong Kong, Aug. 2006.

[36] “Spin Injection through a Co/CuPc Interface,” International Symposium on Applications of Quantum Beam, Kobe, Oct. 2005.

[37] “Metal Doping of Alq3 and Interface Structure,” International Discussion Meeting on Alq, Tokyo, Sept. 2004.

[38] “Electro-phonon interaction in excited states,” Workshop on Electron-Phonon Interactions, Stoughton, Oct. 2002.

[39] “Interface Formation in Organic Semiconductor Based Electronics,” ACS Annual Meeting, Boston, August 2002.

[40] "Interfaces in Organic Thin Film Transistors," SPIE’s 46th Annual Meeting, San Diego, July 2001.

[41] "Interfaces in Organic Light Emitting Diodes," Inter. Conf. Mat. Adv. Tech., Singapore, June 2001.

[42] "Energy Level Pinning and Alignment at Metal/Organic Interfaces," Max G. Mason Symposium, Rochester, April 2001.

[43] “Energy Level Alignment and Charge Injection of the Metal/Organic Interface,” SPIE’s 45th Annual Meeting, San Diego, July 2000.

[44] "Energy Level Alignment in Metal/Organic Interfaces," International Symposium on Organic Molecule Electronics, Nagoya, Japan, May 2000.

[45] "Femtosecond Photoemission Spectroscopy Study of Excited State Dynamics in Organic Photoreceptors," International Symposium on Integrated Optoelectronics, San Jose, January 2000.

[46] "Femtosecond Photoemission Spectroscopy Study of Organic Photoreceptors," Internationa Conference on Advanced Materials, Seoul, Korea, October 1999.

[47] "Characterization of Treated Indium-Tin-Oxide Surface and Interface Formation between Treated ITO and Phenyl Diamine", SPIE's 44th Annual Meeting, Denver, July 1999.

[48] “Growth Modes of Naphthyl-Substituted Benzidine Derivative on Standard and Ultra-Flat Induim Tin Oxide,” AVS Western NY Chapter, Rochester, June 1999.

[49] "Ultrafast Dynamics of Excited States in Organic Photoreceptors," International Workshop on Interfaces in Organic Semiconductors," Nagoya, Japan, June 1999.

[50] “Trap States in Doped tris-8-(hydroxyquinoline) Using Thermally Stimulated Luminescence,” SPIE Symposium on Organic Light Emitting Materials, San Diego, July 1998.

[51] "Trap States of Tris-8-(hydroxyquinoline) Aluminum and Naphthyl-Substituted Benzidine Derivative Using Thermally Stimulated Luminescence," SOMR-97 Symposium on Materials Research, Rochester, Oct. 1997.

[52] "Interfaces in Organic Light Emitting Devices," SPIE Symposium on Organic Light Emitting Materials and Devices, San Diego, July 1997.

[53] "Metal Induced Photoluminescence Quenching of a PhenyleneVinylene Oligomer and its Recovery," American Chemical Society Display Symposium, San Francisco, April 1997.

[54] "A Quick Look at Materials with Femtosecond Photoemission," Ultrafast Dynamics Workshop, Zurich, Switzerland, March 1997.

[55] "Femtosecond Time-Resolved Photoemission Studies of Electron Dynamics at Surfaces," American Physical Society March Meeting, Kansas City, March 1997.

[56] "Ultrafast Electron Dynamics of Metal Surfaces," Canadian Association of Physicists Annual Meeting, Ottawa, June 1996.

[57] "Interface Formation in Organic Semiconductor Devices," American Physical Society March Meeting, St. Louis, March 1996.

[58] "Interface Formation of Metals with Conjugated Polymers," Polymer Science Symposium, Rochester, July 1994.


3. 专著


[1] Y. Gao, “Organic/Metal Interface Properties,” in Introduction to Organic Optoelectronic Materials and Devices, Ed. S. Sun and L. Dalton, 637 (Taylor& Francis CRC Press, New York, 2008).

[2] Y. Gao, “Interface in Organic Semiconductor Devices: Dipole, Doping, Band Bending, and Growth,” in Organic Electronics :Materials, Processing, Devices, and Applications, Ed. F. So, 141 (Taylor& Francis CRC Press, New York, 2009).

[3] Y. Gao, Interface in Organic Semiconductor Devices: Dipole, Doping, Band Bending, and Growth, in Organic Electronics :Materials, Processing, Devices, and Applications, Ed. F. So, 141 (Taylor& Francis CRC Press, New York, 2009).