In_0.53Ga_0.47As/GaAs_0.5Sb_0.5/In_0.52Al_0.48As asymmetric type II quantum well structures lattice-matched to InP grown by molecular beam epitaxy

摘要

In_0.53Ga_0.47As/GaAs_0.5Sb_0.5/In_0.52Al_0.48As asymmetric type II multiple quantum well (MQW) structures lattice- matched to InP substrates were successfully grown by molecular beam epitaxy . In this structure, a large excitonic absorption change by applying an electric field is expected because of its asymmetric structure. Structural dependence of photoluminescence spectrum and optical absorption spectrum was studied. It was found that the emission wavelength changes from 1.4 to 2.5μm with increasing the GaAsSb layer thickness from 0 to 70A, and the thickness dependence of the emission energy agrees fairly well with the calculation. A clear excitonic absorption was observed at 1.5μm at 300K in the asymmetric type II MQW structures.