Optical properties of type-Ⅱ AllnAs/AlGaAs quantum dots by photoluminescence studies

摘要

We report photoluminescence (PL) characterization and model simulation of AllnAs/AIGaAs type-II quantum dots (QDs). A thorough and precise determination of the band parameters for QD and matrix materials is given, focusing on the effects of alloy composition and strain state on the electronic properties. Origins of experimentally observed PL emission peaks are identified through a comparison with the band lineup theoretically determined in this work. We interpret the QD emission as originating from indirect type-II transitions involving electrons in the barrier X valley and heavy holes with S and P symmetry.