Hydrogenation and annealing effects in p-type ZnSe thin films grown on GaAs (100) substrates

Abstract

Photoluminescence (PL) and Raman scattering measurements have been carried out to investigate the hydrogenation and annealing effects in p-type ZnSe epilayers grown on n-type GaAs (100) substrates by molecular beam epitaxy. After hydrogenation, the PL spectra showed that the deep acceptor-bound exciton peak disappeared and that the peak position of the donor–acceptor pair peak shifted to a higher energy. When the hydrogenated ZnSe/GaAs heterostructure was annealed at 300 °, a bound exciton due to neutral acceptors appeared. The Raman intensity of the plasma longitudinal optical-phonon-coupling mode increased after hydrogenation. These results indicate that the crystallinity of the p-type ZnSe epilayers grown on n-type GaAs substrates is improved by hydrogenation and that hydrogenated and annealed ZnSe films grown on GaAs substrates hold promise for potential application as buffer layers for the growth of Zn1−xMgxSySe1−y active layers.