Thermal Annealing of GaInNAs/GaAs Quantum Wells Grown by Chemical Beam Epitaxy and Its Effect on Photoluminescence

Abstract

The thermal annealing effect on the photoluminescence (PL) characteristics of GaInNAs/GaAs quantum wells (QWs) grown by chemical beam epitaxy (CBE) using radical nitrogen is presented. The room-temperature PL peak intensity of GaInNAs/GaAs QWs increased about 70 times and the linewidth of PL spectra decreased after annealing at 675°C for 30 seconds. The blue shift of the PL peak wavelength of GaInNAs/GaAs QWs and GaNAs/GaAs QWs, due to the structural change of QWs was observed. It was found that the blue shift was caused by In–Ga interdiffusion rather than nitrogen atom diffusion. The interdiffusion caused by defects is thought to reduce the number of non radiative centers, resulting in the improvement of PL characteristics. The optimum annealing temperature depends on the composition.