Abstract
The talk consists of two parts:
1. Antimonide type-II superlattice for IR applications: The study of InAs/InAsSb T2SL on GaSb and its application to IR lasers was started in the early ’90s. The observation of a 412 ns long carrier lifetime in a long-wavelength infrared (LWIR) InAs/InAsSb T2SL in 2011 triggered extensive research on the fundamental materials properties and device applications. Pressure-dependent photoluminescence (PL) experiments revealed some underlying material physics of these long carrier lifetimes. Some of the device applications will also be discussed.
2. Heterovalent integration and device applications: The study the monolithic integration of these families: II-VI (BeMgZnCdHg)(SeTe), III-V (AlGaIn)(BiPAsSb), IV-IV (SiGeSn), and IV-VI (PbSe, PbTe) semiconductor binaries and their alloys lattice-matched to GaAs, GaSb, InP, InAs or InSb substrates. These materials have direct bandgaps covering a very broad energy spectrum from far IR to UV (0 ~ 4 eV) and small thermal mismatch, offering opportunities to study new physics in quantum materials, such as electrical-field-induced topological insulators in heterovalent superlattice and thin-film superconductor on semiconductor (a-Sn/InSb), but also enables new solar cells, multi-color photodetectors, resonant tunneling diodes, and facilitates monolithic integration of various materials without misfit dislocations to ensure the highest quality for device applications.

Bio

Professor Zhang did his thesis research at the Max Planck Institute for Solid States and received this doctoral degree in physics from the University of Stuttgart in 1991. He then worked as an Assistant Research Engineer at UCSB before he joined Hughes Research Labs (HRL) in 1993. In 1996, he was appointed Associate Professor in the Department of Electrical Engineering at ASU and was promoted to full professor in 2000. He edited 3 books, published 4 book chapters and more than 300 peer-reviewed journal and conference proceeding papers, presented 400 invited and contributed conference presentations, 18 issued and pending US patents, advised over 30 PhD students and supervised over 40 postdocs and visiting scholars. He is a fellow of IEEE and OSA and has served as the Associate Dean for Research at the Fulton Schools of Engineering, the director and Chair of the Governance Board of ASU NanoFab, and the founding director of the Center for Photonics Innovation. His areas of research interest include Molecular Beam Epitaxy (MBE) growth of II-VI, III-V, IV-IV, and IV-VI materials, optical properties of semiconductor heterostructures and their applications in solar cells, photodetectors, lasers, and transistors. He is currently the chair and the co-chair of the international advisory boards for the International Conference on MBE and the North America Conference on MBE, respectively.