Time-resolved spectroscopy of excitons bound at shallow neutral donors in HVPE GaN

Abstract

Time-resolved photoluminescence (TRPL) data for temperatures 2–150 K are presented for two thick HVPE samples grown in two different laboratories. The samples both have residual O and Si shallow donor concentrations in the 10 16 cm −3 range. The radiative decay time for neutral donor-bound excitons (DBEs) related to these donors is found to be about 300 ps. The decay of the DBEs at longer decay times is found to be related to feeding from the free exciton–polariton states. At elevated temperatures the decay of the DBE is very similar to the free exciton decay.