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

Purdue University, West Lafayette IN

Investigators

Abstract

Non-Technical Abstract The proposed research exploits a range of optical techniques in order to discover the behavior and properties of new semiconductors constantly being produced for advanced applications. High temperature/high power devices based on wide gap semiconductors such as diamond and having diamond like structures (SiC,ZnO,GaN, etc); a class of semiconducting materials known as "spintronic compounds" with magnetic constituents; and materials obtained with deliberate addition of specific impurities to semiconductors will be studied. These illustrative examples underscore the excitement and the intellectual appeal of semiconductors and their ever increasing applications in consumer, industrial, space, and defense electronics. The graduate students and postdoctoral research associates with the program will be well prepared for research careers by this exposure to the cutting edge work. With the expertise thus acquired, they will become future creative members of the academia as well as national, industrial, and defense science laboratories in the coming decades. Technical Abstract The project explores collective and localized excitations in tetrahedrally coordinated semiconductors and their hetero-nanostructures exploiting a variety of spectroscopic and optical techniques (Raman, Brillouin, Infrared and Modulation Spectroscopy; magneto-optics - Faraday, Voigt, and Zeeman effect). Signatures unique to the II-VI diluted magnetic semiconductors, isotopically controlled II-VI (ZnO and CdSe), III-V (GaN), IV-IV (SiC polytypes) and elemental (diamond) will be explored and delineated in the context of electronic, magnetic, and vibrational excitations and their behavior under external perturbations. Novel effects resulting from dimensional constraints in hetero-and nano-structures will be investigated. Graduate students and undergraduate students (selected for "research experience") will acquire skills in the state-of-the-art spectroscopy applied to forefront areas in contemporary semiconductor physics, and, in turn, become part of the scientific/technical condensed matter community and have a positively impact on materials science.