Title:Highly-Mismatched Semiconductor Alloys: Theory, Experiments and Applications

Speaker:Prof. Junqiao Wu (Department of Materials Science and Engineering, University of California, and Materials Sciences Division, Lawrence Berkeley National Laboratory )

Time:10:00 AM, Dec.30, 2008

Venue:Academic Conference Center, Institute of Semiconductors, CAS

Abstract：In recent years a unique class of materials, highly mismatched semiconductor alloys (HMAs), was identified. HMAs are composed of isovalent constituents with distinctly different electronegativity alloyed at fractions far beyond the solubility limit. Unlike conventional semiconductor alloys where the band structure generally interpolates between the end-point materials, in HMAs the hybridization between the extended states of the majority component and the localized states of the minority component results in a drastic band restructuring. Novel optical and electronic properties were observed in a broad range of HMAs such as GaAs1-xNx, ZnSe1-xOx, Ge1-xSnx, GaAs1-xBix, etc. In this talk he will review the theoretical basics and experimental findings in the development of the HMAs. He will also discuss the state-of-the-art applications of HMAs in a new generation of photovoltaics and thermoelectrics.