Dynamical transport of photoexcited carriers between shallow and deep quantum wells embedded in a GaAs/AlAs superlattice

摘要

Temperature dependence of the emission properties in a novel compositequantum-well-structure consisting of wide and narrow GaAs quantum wells (QWs) embeddedin a GaAs/AlAs short-period superlattice (SPS) has been studied by steady-state andtime-resolved photoluminescence (PL) measurements. At low temperature (~20 K), distinctPL peaks originating from the QWs and SPS are observed. When temperature is increased to60 K, the PL intensity of the wide QW with deep confinement states significantly increases,while the ones of the narrow QW and the SPS gradually decrease. Above 100 K, however, theformer PL intensity decreases and the latter ones increase. Temperature dependence of themeasured PL decay behaviors directly evidences that the complex PL properties of thecomposite QWs are due to the interplay of the photoexcited carriers between the deep andshallow QWs by Bloch-type transport in the SPS.