Carrier tunneling effects on the temperature dependent photoluminescence of InAs/GaAs quantum dot: Simulation and experiment

Abstract

Considering the direct quantum tunneling of carrier, we propose a new carrier rate equation model to simulate the temperature dependent photoluminescence (TDPL) of InAs/GaAs quantum dots (QDs). The TDPL showed abnormal variations: the peak rapid redshift, linewidth shrinkage, and thermal activation energy all decreased with increasing tunneling strength. A criterion, which could be used to evaluate the tunneling strength, has been developed. That is, smaller tunneling strength coefficient α indicates higher carrier tunneling strength. Meanwhile, the criterion is also demonstrated via comparative experimental results of InAs QDs grown on different patterned GaAs substrates. It is found that, to some extent, the tunneling strength would be enhanced by decreasing the dot-dot distance for closely arranged QDs ensembles.