Speaker

Yuanyue Liu

Texas Materials Institute and Department of Mechanical Engineering at University of Texas at Austin

Date＆Time

2019.08.15 (Thur) AM 9:30

Location

Abstract

Two-dimensional (2D) materials possess attractive properties for many applications such as (opto)electronics and electrocatalysis. However, their developments are impeded by a number of significant challenges, many of which root in the 'problems of electrons'. On the physics side, the electrons/holes in current 2D semiconductors do not move fast enough under electric field (i.e. low mobility), impeding their use in high-performance electronics and optoelectronics. On the chemistry side, the current 2D electrocatalysts still suffer from relatively low activity/selectivity, hindering their use in efficient energy conversion. These challenges urge for an improved understanding of the electrons in 2D materials, and using these insights to design/discover 2D host materials with better performance.

Here I will discuss our recent progress in understanding the physics and chemistry of electrons in 2D materials, including:  (1) what limits the intrinsic mobility of electrons in 2D metal dichalcogenides [1], the mobility in group-15 monolayers, and the guidelines towards high-mobility semiconductor; (2) how the electronic structure of 2D material affects its binding with atoms/molecules, which allows us to explain some puzzling observations and discover materials with desired performance [2-5].

[1] L. Cheng, Y. Liu, JACS, 2018 DOI: 10.1021/jacs.8b07871

[2] D. Kim, J. Shi, Y. Liu, JACS, 2018, 140, 9127

[3] Y. Liu, J. Wu, K. P. Hackenberg et al, Nature Energy, 2017, 6, 17127

[4] Y. Liu, B. Merinov, W. A. Goddard III, PNAS 2016, 113, 3735

[5] Y. Liu, Y. M. Wang, B. I. Yakobson, B. C. Wood, Phys. Rev. Lett. 2014, 113, 028304