学术报告——Surface Functionalization of MoS2

 

时    间:2019年1月7日(星期一)14:00

地    点:北区光电所三楼多功能厅

主持人:王义平 教授(深圳大学)

报告人:王顺 教授(华中科技大学)

报告人简介:

1982年生于湖北武汉,教授,现任基本物理量测量教育部重点实验室副主任。2005年华中科技大学本科毕业,2010年美国明尼苏达大学物理系获得凝聚态物理博士学位。后在明尼苏达大学化工与材料系进行博士后研究。2013年起在上海交通大学任特别研究员。 2016年6月起为华中科技大学教授。参与两项“973”项目并主持一项上海市自然科学基金项目。发表论文多篇,其中Physical Review Letters五篇,Nature Communications一篇。 王顺教授曾成功利用真空和离子液体作为绝缘层制备高性能的有机半导体晶体管,同时也致力于采用石墨烯、TaS2、 NbS2 以及NbSe2等二维材料制备异质结的研究工作。其研究兴趣包括金属绝缘体转变、安德森局域化、超导和电荷密度波,以及这些物理现象在电子工程和生物医学工程上的应用。


报告摘要:

Surface functionalization has proven to be a powerful tool to tune the electronic properties of two-dimensional materials. However, the microscopic origin of the modification of electronic properties is not well understood. I will talk about the surface functionalization of MoS2 with a sulfur-containing chemical compound lipoic acid (LA). Using a combination of atomic force microscopy, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, we demonstrate that LA molecules are both physically adsorbed and chemically bonded to MoS2 surface. After surface treatment, a significant increase of current is observed in MoS2 field effect transistors (FET) with thickness ranging from single layer to over ten layers. By systematically analyzing the I-V characteristics of MoS2 FETs, we show that mobility enhancement rather than charge transfer is responsible for the current increase. This mobility enhancement, with a clear thickness dependence, can be explained by the suppresion of charge impurity scattering after the surface functionalization. This technique provides new opportunities to tailor the chemical and electronic properties of MoS2 and our results shed new light on the understanding of charge transport mechanism in surface treated MoS2 FETs.