9458046 Ringel Research will be directed toward an improved understanding of the electronic properties of dislocations in lattice mismatched semiconductor heterostructures, their relationship with dislocation microstructure, and an exploration of methods to electrically passivate the deleterious nature of dislocations. The effects of impurities and extrinsic processes such as those encountered for specific device applications, will be considered in detail. The focus is on three technologically important semiconductor systems, III-V/Silicon, Germanium-Silicon/Silicon and nitride based wide bandgap III-V materials. The proposed research incorporates a unique array of complementary electronic, microstructural, and atomic resolution measurement techniques, in addition to epitaxial growth and processing facilities to perform the proposed studies. This research will make fundamental contributions to the materials science of dislocations in semiconductor heterostructures from an electronic perspective which, coupled with an improved understanding of dislocation control, will have significant impact on integration of lattice mismatched electronic materials for advanced device applications. %%%%%% This research is expected to provide improved fundamental understanding of the electronic properties of defects resulting from the monolithic integration of dissimilar semiconducting materials, and to investigate methods to control the undesirable properties of these defects. The results will be of importance to the development of multi-functional devices and integrated optoelectronics that consist of different classes of materials integrated onto a common substrate. An important feature of this research project is the training of graduate and undergraduate students in a fundamentally and technologically significant area of materials and processing research. ***
