Temperature dependence of the photoluminescence emission from InxGa1−xAs quantum wells on GaAs(311) substrates

We studied the photoluminescence (PL) properties of In0.2Ga0.8As/GaAs quantum well structures grown by molecular beam epitaxy on (311)-oriented substrates. The structure consists of three quantum wells (QWs) of 100, 50, and 25 A nominal thickness. The temperature dependence of the PL emission from the QWs in the range of 5–250 K is reported. Three models by Varshni, Vina, and Passler, respectively, were employed to analyze the variation in the excitonic energy transitions as a function of temperature. We compared the excitonic behavior with the band gap temperature dependence of bulk In0.2Ga0.8As and found a difference, as opposed to the unstrained AlGaAs/GaAs system. We attributed this difference to the modification of the QW energy levels by the quantum confinement Stark effect, which is temperature and well width dependent.