Nanostructures for Enhanced Electron/Hole Conversion

摘要

In this program we used molecular beam epitaxy (MBE) to create epitaxial metal-semiconductor structures containing embedded metallic nanoparticles, metallic epitaxial films and epitaxial metal-semiconductor junctions. We incorporated epitaxial metallic nanoparticles of erbium arsenide and erbium antimonide in GaAs, InOaAs and GaSb structures by molecular beam epitaxy. The metallic nanoparticles in semiconductors produced: (1) electrical doping of semiconductors, (2) electron/hole recombination enhancement, (3) electron/hole tunnel junction enhancement. (4) thermal conductivity control, (5) microwave rectification improvement and (6) strong electron plasma resonances. Tunnel currents of GaAs np junctions were enhanced by up to five orders of magnitude by the embedded nanoparticles. Electron-hole recombination times in a series of ErAs/InGaAs codepositions were reduced to less than 100 femtoseconds. We produced the first epitaxial growth of GdN on GaN. This research thus established a foundation for development of improved artificially structured thermoelectric power generation materials, for new materials for terahertz wave generation and detection and for development of highly conducting contacts for the nitride semiconductors.