Optical properties of GaInNAs/GaAs prepared by molecular beam epitaxy Original Research Article

Optical properties of GaInNAs are studied with emphasis on photoluminescence (PL) and photoreflectance (PR) using GaInNAs single quantum wells (GaInNAs-SQW) and thick GaInNAs layers lattice-matched to GaAs (LM-GaInNAs) grown by solid-source molecular-beam epitaxy. First, a blue-shift of band-gap energy as a result of a rapid thermal annealing (RTA) has been confirmed by both PL and PR. Temperature-dependent PL and PR spectra were measured. At low temperature, GaInNAs-SQWs exhibited a PL due to the localized exciton (LE), and the localization was strongly reduced by RTA. A very high-quality GaInNAs-SQW exhibited very intense PL with small half-width (10–20 meV for 8–300 K) without LE emission. In LM-GaInNAs, low-temperature PL exhibited both the LE emission and a deep PL band. Temperature-dependent PL showed that LM-GaInNAs contains large number of non-radiative centers. PR spectra of LM-GaInNAs were composed of more than two transitions, and their relative intensity depended on temperature and annealing.