Temperature Dependence of the Photoluminescence in GaAsGaAlAs Multiple Quantum Well Structure

Abstract

Abstract The temperature dependence of the photoluminescence (PL) of GaAs/GaAlAs multiple quantum wells is investigated. Emissions related to transitions between n = 1, 2, 3 electron and hole subbands are observed. Theoretical evaluation of the energy levels fits nicely the experimental data. The temperature dependence of peak position and photoluminescence intensity and the dependence of PL intensity on the power excitation show that there are three different temperature regions. At low temperatures (22 to 40 K) the main emission is ascribed to exciton recombination while at temperatures higher than 100 K it can be attributed to free carrier recombination. In the intermediate temperature region the PL involves both, excitonic and free carrier recombination. Thermally activated non‐radiative recombination processes strongly reduce the luminescence quantum efficiency.