报告时间：7月14日上午9:30
报告地点：科技创新大楼C501室
报告题目：Phase Engineered Transition Metal Dichalcogenides as Electrodes for Energy and Electronics

Abstract:

Phase Engineered Transition Metal Dichalcogenides as Electrodes for Energy and Electronics
Manish Chhowalla Rutgers University

Two-dimensional transition metal dichalcogenides (2D TMDs) — whose generalized formula is MX2, where M is a transition metal of groups 4–7 and X is a chalcogen —consist of over 40 compounds. Complex metal TMDs assume the 1T phase where the transition metal atom coordination is octahedral. The 2H phase is stable in semiconducting TMDs where the coordination of metal atoms is trigonal prismatic. High performance of electronic and opto-electronic devices have been demonstrated with semiconducting TMDs while interesting condensed matter effects such as charge density waves and superconductivity have been observed in bulk metallic 1T phase TMDs. However, stability issues have hampered the study of interesting phenomena in two-dimensional 1T phase TMDs. Recently there has been a surge of activity in developing methodology to reversibly convert 2D 2H phase TMDs to 1T phase. In contrast with typical phase transformation conditions involving pressure and temperature, phase conversion in TMDs involves transformation by chemistry at room temperature and pressure. Using this method, we are able to convert 2H phase 2D TMDs to the 1T phase or locally pattern the 1T phase on 2H phase 2D TMDs. The chemically converted 1T phase 2D TMDs exhibit interesting properties that are being exploited for catalysis for hydrogen evolution reaction, source and drain electrodes in high performance field effect transistors, and as electrodes for energy storage. In this contribution, I will summarize the key properties of 2D 1T phase TMDs and their applications as electrodes for energy and electronics.

Short Biobraphy:

Manish Chhowalla is a Professor and Associate Chair of the Materials Science and Engineering Department at Rutgers University. He is also the Director of Nanotechnology for Clean Energy NSF IGERT Program and the Donald H Jacobs Chair in Applied Physics (2009 – 2011). From June 2009 – July 2010, he was a Professor in the Department of Materials at Imperial College London. He has won the NSF CAREER Award for young scientists as well as the Sigma Xi Outstanding Young Investigator for the Mid Atlantic Region. Before Rutgers, he was a Royal Academy of Engineering Postdoctoral Research Fellow at the University of Cambridge after completing his Ph.D. in Electrical Engineering there. Prior to his PhD, he worked for Multi-Arc Inc. (now Ion Bond) where he developed one of the first applications of “amorphous diamond” thin films. His technological interests are in the synthesis and characterization of novel low dimensional materials and their incorporation into devices for electrical, optical, thermal and mechanical applications. He has over 200 publications with over 16,800 citations (h-index = 61) on these topics and has given > 200 invited/keynote/plenary lectures.