Epitaxial III-V based nanocomposites
Epitaxial III-V based nanocomposites are comprised of small rare-earth monopnictides (RE-V) nanoparticles embedded in thermoelectric semiconductor alloys during MBE growth. The inclusion of nanoparticles increases the number of interfaces leading to an increase in phonon scattering and a decrease in thermal conductivity. In addition, these particular nanoparticles are believed to provide enhanced electrical conduction through electron filtering mechanisms. RE-V materials are primarily cubic materials with the rock-salt crystal structure and have lattice parameters commensurate with many of the III-V based semiconductors. The RE-V materials are thermodynamically stable with their III-V semiconductor counterparts and the rare-earth elements have low solubilities in the host semiconductors leading to the precipitation of nanoparticles at relatively low concentrations. This supports the growth of single crystal, low dislocation density nanocomposites with coherent interfaces for electron conduction and phonon scattering.