Luminescent properties of GaAsBi/GaAs double quantum well heterostructures

GaAsBi/GaAs double quantum well (DQW) heterostructures are grown at low temperatures using molecular beam epitaxy without growth interruption and studied by means of high-resolution x-ray diffraction and continuous wave photoluminescence (PL). Line shape analysis of PL spectra measured at various excitation densities allows reveals QW coupling due to tunnelling. It is shown that an efficient PL of GaAs/GaAs1−xBix/GaAs DQWs is significantly more thermally stable than that from a single quantum well (SQW) structure of similar composition. Such stabilization is described in terms of carrier redistribution between coupled quantum wells and is caused by carrier capture in the QW, thermal emission, and diffusion in the barrier.