报告题目：Possible Routes towards Challenges in 2D Semiconductors from First-Principles: Chemical Doping and Carrier Mobility

报告人：杨吉辉，复旦大学物理系

报告时间：2022年11月26日下午14:00

腾讯会议：905 5677 7131  密码：2022

报告摘要

　　Ever since the discovery of graphene, two-dimensional (2D) semiconductors have attracted intensive research interests due to their novel physics and potential applications. So far, there are more than one thousand of 2D materials that have been discovered either theoretically or experimentally and some of them have been made into 2D devices such as FETs and p-n junctions, which are expected to complement traditional 3D devices with the Moore's law approaching physical limit. However, from conceptual to practical 2D semiconductor devices, many challenges need to be overcome. Here in this talk, I will present our first-principles works aiming to offer possible routes towards the two challenges in 2D semiconductors, which are the chemical doping difficulty and low carrier mobility problem. For the first challenge, the physical mechanisms behind chemical doping difficulty in 2D are revealed and demonstrated by first-principles calculations, based on which strategies are proposed to improve doping efficiencies. For the second challenge, the carrier scattering mechanisms in 2D are understood using our proposed phonon-energy-resolved properties. The general rules based on easily-calculated fundamental electronic and phonon properties for screening possible high-mobility 2D semiconductors are established, guided by which we have found several high-mobility systems and confirm their mobility properties using first-principles calculations and considering all electron-phonon couplings. These works will be helpful for the further development of 2D devices.

报告人简介

杨吉辉，复旦大学物理学系青年研究员。分别于2008和2013年在复旦大学取得本科和博士学位，导师为龚新高院士。毕业之后先后在美国国家可再生能源实验室和莱斯大学从事博士后研究工作，合作导师分别为魏苏淮和Boris I. Yakobson教授，2018年10月加入复旦大学。主要研究方向为计算半导体物理，用基于第一性原理计算的方法来研究半导体材料中与电子产生、复合、输运、分离等相关的物理性质和物理过程，同时发展相应的计算方法和半导体理论，设计和发现新型功能半导体。在Nature Materials、PRL、Nano Letters、JACS等杂志上发表论文70余篇，Google Scholar被引6600多次，H因子34。目前的研究兴趣为非平衡载流子行为、半导体缺陷非平衡调控、电声耦合相关的物理性质和过程等。

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