All-2D metal/semiconductor interface based on MoS2

甘立勇博士

沙特阿卜杜拉国王科技大学

报告时间：4月28日（星期一）下午15:00

报告地点：物理楼233

Abstract

The MoS2/graphene hybrid system has been reported to show high electron conductivity and excellent electrochemical performances.Therefore, combining MoS2 with other 2D layered materials is a viable and promising way to realize vertical heterostructures and hybrid all-2D devices. In MoS2/Ti2C and MoS2/Ti2CY2 (Y = F and OH) semiconductor/metal contacts, we demonstrate a metallic interface between MoS2 and Ti2C. For MoS2/Ti2CY2 Schottky contacts, the Schottky barrier height strongly depends on the workfunctions of the two materials, suggesting that the same junctions as to conventional metals can also be realized in stacked 2D materials. The tunable barrier heights demonstrate that there is no limitation to fabricate all-2D vertical heterostructures.

2D TMDCs constitute a large family of materials and the electronic properties range from ferromagnets (such as VS2)to semiconductors,opening the possibility of ferromagnet/semiconductor contacts for engineering all-2D electronic devices and spin injection. We investigate Schottky contacts in 2D TMDCs, focusing on the nonmagnetic semiconductors MoS2 and WS2 and the ferromagnet VS2 as prototypes. The degree of p-type doping and corresponding Schottky barrier heights can be well controlled by vertical compressive pressure. A comprehensive picture is derived to understand the mechanism. We also show that magnetic proximity effects induce a 100% spin polarization in MoS2 and WS2 at the Fermi level in a wide pressure range, reflecting great suitability of VS2 as substrate for spin injection purposes.

个人简介：
甘立勇，2007年重庆大学应用物理系本科毕业，获理学学士学位；2007年进入华南理工大学物理学院，"1+4"于2012年获得博士学位；毕业至今在沙特阿卜杜拉国王科技大学从事博士后工作，研究方向为功能材料性能优化与设计的理论模拟。主要包括过渡金属表面催化、锂（钠、镁）离子电池、固体氧化物燃料电池、金属-半导体界面、半导体-半导体界面等领域。至今在重要国际学术期刊（如ACS Nano, J. Phys. Chem. Lett., Phys. Rev. B）发表论文近20篇，并于2013年获得华南理工大学优秀博士学位论文奖。