High-Quality GaAs Films on Si Substrates Grown by Atomic Hydrogen-Assisted Molecular Beam Epitaxy for Solar Cell Applications

Minority carrier lifetimes of high-quality n-GaAs heteroepitaxial thin films grown on vicinal Si(100) substrates by atomic hydrogen-assisted low-temperature molecular beam epitaxy (MBE) technique have been investigated. Photoluminescence decay characteristics have been evaluated and a minority carrier lifetime of as high as 8.0 ns has been successfully obtained, which is the highest value reported to date. These results are regarded as of particular importance for high-performance optoelectronic device applications especially for tandem solar cells.