Raman, Brillouin, Infrared and Modulation Spectroscopy of Collective and Localized Excitations in Tetrahedrally Coordinated Semiconductors and Their Heterostructures

Purdue University, West Lafayette IN

Investigators

Abstract

This project is devoted to the experimental and theoretical investigation of collective and localized excitations in tetrahedrally coordinated semiconductors and their hetero-and nanostructures by a variety of optical (spectroscopic) techniques. The research will focus on novel phenomena and unique properties produced in these materials by the deliberate introduction of chemical impurities as donors and acceptors, or as isoelectronic and magnetic constituents. Electronic properties of isotopically controlled diamond, Si and Ge will be investigated. The program will explore and delineate the electronic states of donor-bound electrons and acceptor-bound holes in diamond, in III-V and III-VI magnetic (spintronic) multinaries and in chalcopyrites, genealogically derived from III-V and II-VI semiconductors. Collective and localized electronic and vibrational states will be investigated in these semiconductors and their nanostructures with magneto- and piezo-spectroscopy. Graduate students and undergraduate students participating in the program will acquire skills in Raman, Brillouin, infrared and modulated reflectivity/transmission spectroscopy applied to issues at the forefront areas in current semiconductor physics and, in the process, be trained for careers in academe, industry, and government. Research proposed deals with applications of several optical techniques to the behavior and properties of advanced semiconductor materials. These materials play a significant role in the current technology and hold the promise and potential for significant applications. High temperature/high power electronic devices based on wideband gap, ultra hard semiconductors, e.g. diamond; new generations of solid state electronics in which spin-polarized charge carriers are exploited using spintronic materials; the manipulation of semiconductor properties by the deliberate introduction of specific impurities or by controlling the isotopic composition: These are illustrative examples of the excitement and intellectual challenges in the physics of semiconductors and their future applications. Participants in the program - graduate students and postdoctoral research associates - will acquire versatile expertise for careers in academia, national laboratories as well as in research and development in the opto-electronics industry.