Robert P. Devaty Associate Professor, Physics and Astronomy


402 Allen Hall
Pittsburgh, PA


Nanoscience Aspects of Large Bandgap Semiconductors

The research of the Large Bandgap Semiconductors Group (Profs. W.J. Choyke and R.P. Devaty) focuses on the polytypes of silicon carbide, but we have also worked on the III-nitride compounds (AlN, GaAlN, etc.) and diamond. We study optical and electrical properties by a variety of techniques, and also put considerable effort into preparation of specialized samples. Regarding nanoscience and technology, examples of relevant work include:

Devaty-Fabrication and investigation of porous SiC. As an example, the figure shows a SEM image of porous SiC having a quasi-ordered array of parallel nano-columnar pores. These pores can extend through an entire sample, up to 200 μm thick and beyond.
-Investigations of polytype inclusions which behave as quantum wells. For example, we have observed 3C SiC quantum wells in 4H SiC and used the photoluminescence spectra to obtain a value for the spontaneous polarization of 4H SiC. These quantum wells can have excellent, strain-free interfaces.
-We are investigating SiC as a tool for nano-machining applications, as a substitute for diamond, towards applications for which diamond does not work well or at all.

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