Temperature dependence of photoluminescence of QD arrays

Abstract

It is essentially important to understand the temperature dependence of the photoluminescence of multimodal quantum dot (QD) arrays for the realization of efficient photonic devices. In this paper, the dynamics processes of different density multimodal QD arrays were fitted by using the rate equation model. It is shown that, in high density QD arrays, the intensity of photoluminescence of different QD families has different temperature dependence, and the intensity of photoluminescence is quenched as the temperature increases in low density QD arrays. In high density QD arrays, as the temperature increases, the carriers will be thermally excited into the wetting layer from QDs, and then some of them will be recaptured by the big scale QDs; carrier coupling takes place between the different QD families, while in low density QD arrays, the carrier transfer between different QD families will be limited. Temperature dependence of the maximum of the ratio of photoluminescence intensity of different QD families strongly depends on the difference of thermal activation energies.