9531133 Narayanamurti A unique, variable temperature, Ballistic Electron Emission Microscope (BEEM) recently developed at Santa Barbara will be used to perform the first spatial studies of local electronic band structure and transport of novel compound semiconductor heterostructures and quantum wells in GaInP/GaAs and A1GaN/GaN. Both of these materials systems have great technological importance for optoelectronic devices, and there is a strong electronic materials and device effort at UCSB in this area. Yet the fundamental knowledge of important electronic parameters, such as heterjunction band offsets, is either poorly understood (GaInPGaAs) or unknown (A1GaN/GaN). Initial BEEM studies at UCSB in the prototypical A1xG1-xAs/GaAs system have very recently shown the power of BEEM to perform spectroscopy of semiconductor heterostructures buried spatially below the Schottky barrier and gives us confidence in the potential of the technique for probing new materials systems Such studies using BEEM have never been done before. It is anticipated that the results of this undertaking will yield a concrete body of invaluable information which will lead to understanding of transport in quantum heterostructures, and will enable the characterization of technologically important (and heretofore poorly understood) semiconductor materials on a local scale. ***