题 目：van der Waals Junctions as Low-resistance Contacts for Two-Dimensional Layered Semiconductors beyond Graphene 

报告人：Zhixian Zhou (周志贤),Associate Professor（Department of Physics and Astronomy, Wayne State University, 666 W Hancock Street,Detroit, MI 48201）
时 间：11月23日（周三），上午9:30
地 点：南校区第一实验楼423会议室

Abstract：The successful isolation of two-dimensional (2D) graphene has stimulated research on a broad range of other 2D materials, among which layered transition metal dichalcogenides (TMDs) have attracted particular attention. The semiconducting members of the TMD family including MoS₂, MoSe₂ and WSe₂ have not only demonstrated many of the "graphene like" properties highly desirable for electronic applications such as a relatively high mobility, mechanical flexibility, chemical and thermal stability, and the absence of dangling bonds, but also have a substantial band gap (1 ~ 2 eV depending on the material and its thickness), which is absent in 2D graphene but required for mainstream logic applications. However, a major bottleneck in electronic applications of TMDs is their tendency to form a substantial Schottky/tunneling barrier with most electrode metals, which severely limits their performance. In this talk, I will discuss our recent work aiming to overcome this fundamental challenge and  subsequently explore the intrinsic transport properties of TMDs.^1-3

1.Chuang, H.-J.; Chamlagain, B.; Koehler, M.; Perera, M. M.; Yan, J.; Mandrus, D.; Tománek, D.; Zhou, Z. Low-Resistance 2D/2D Ohmic Contacts: A Universal Approach to High-Performance WSe2, MoS2, and MoSe2 Transistors. Nano Letters 2016, 16, 1896-1902.

2.Chuang, H.-J.; Tan, X.; Ghimire, N. J.; Perera, M. M.; Chamlagain, B.; Cheng, M. M.-C.; Yan, J.; Mandrus, D.; Tománek, D.; Zhou, Z. High Mobility WSe2 p- and n-Type Field-Effect Transistors Contacted by Highly Doped Graphene for Low-Resistance Contacts. Nano Letters 2014, 14, 3594-3601.

3.Perera, M. M.; Lin, M.-W.; Chuang, H.-J.; Chamlagain, B. P.; Wang, C.; Tan, X.; Cheng, M. M.-C.; Tománek, D.; Zhou, Z. Improved Carrier Mobility in Few-Layer MoS2 Field-Effect Transistors with Ionic-Liquid Gating. ACS Nano 2013, 7, 4449-4458.

Short Bio：Dr. Zhixian Zhou received his PhD from Florida State University/National High Magnetic Field Laboratory in 2004. After working at the Oak Ridge National Laboratory as a postdoctoral research associate, he joined Wayne State University as an assistant professor in 2007 and was promoted to associate professor with tenure in 2013. Dr. Zhou has been working in the field of low-dimensional materials and electronics for over ten years.