Thermophotovoltaic (TPV) Systems are used for the direct conversion of thermal energy (i.e., heat) into electricity. This project will develop high voltage, series-interconnected, low-band-gap TPV devices for thermal-to-electric energy conversion in applications that use heat sources such as radio isotope power supplies for space power. Several approaches are being pursued to effect device isolation, thus circumventing the problems associated with the lack of semi-insulated GaSB or InAS substrates. In Phase I, significant improvements in GaSB-based TPV cells were achieved. Also, several approaches were identified and developed for isolation and interconnection of TPV device elements. These include epitaxial lateral overgrowth, bonding, and film transfer to a surrogate substrate. In Phase II, the epitaxy and fabrication processes initiated in Phase I will be utilized to make monolithic, series-interconnected TPV arrays.

Commercial Applications and Other Benefits as described by the awardee. This device should find should application to radio-isotope power supplies, portable generators, and thermal-to-electric co-generation.