Title: Salient physics of transition metaldichalcogenides

Speaker: Prof. Shengbai Zhang (Department of Physics, Applied Physics, & Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA)

Time: Aug 20, 2019 10:00AM

Venue:No. 303 meeting room of building 2, IOS, CAS

Abstract：Based on the recent theory of built-in potential [1], we advance the theory of intrinsic band alignment where the reference vacuum-level position in an infinite solid is recovered and serves as the common reference among dissimilar bulk materials [2]. Important to the theory is the recognition of an orientation dependence of bulk energies with respect to the vacuum level position due to an intrinsic bulk quadrupole – a quantity that measures the difference between the average electrostatic potential (which is set to zero in most bulk calculations) and the aforementioned vacuum level position. Our finding is expected to impact a wide range of practical applications ranging from surface workfunction, solid-state band offset, deformation potential, electrochemical potential of a cell, to redox potential in electrochemistry.

Biography:Prof. Zhang’s research involves first-principles and multiscale calculations of structural and electronic properties of materials, which range from inorganic crystalline, amorphous semiconductors, metals, and their nanostructures to organic materials, bio functional groups, and solutions. While his research interests are primarily in the fundamental physics of materials, they have always been inspired by the needs for sustainable energy and environment, technology leadership, and national security. Prof. Zhang has published about 280 peer reviewed papers with high impact to the fields (citations >11,000, Hirsch Index = 56).