Excitonic mobility edge and ultra-short photoluminescence decay time in n-type GaAsN

Abstract

We use time-resolved photoluminescence (PL) spectroscopy to study the recombination dynamics in Si-doped GaAsN semiconductor alloys with a nitrogen content up to 0.2%. The PL decay is predominantly monoexponential and exhibits a strong energy dispersion. We nd ultra-short decay times on the high-energy side and long decay times on the low-energy side of the photoluminescence spectrum. This asymmetry can be explained by the existence of an additional non-radiative energy transfer channel and is consistent with previous studies on intrinsic GaAsN epilayers. However, the determined maximum decay times of GaAsN:Si are signi cantly reduced in comparison to undoped GaAsN. The determined excitonic mobility edge energy constantly decreases with increasing N content, in agreement with the two-level band anticrossing model.

Photoluminescence Mechanism in Heavily Si‐Doped GaAsN

“…For Si doped n‐type dilute GaAsN, the photoluminescence (PL) mechanism was partially discussed, [ 9,10 ] but it has not been clarified in the case of heavily Si‐doped GaAsN. Therefore, in this study, the PL mechanism is investigated in heavily Si‐doped dilute GaAsN to compare with that in a moderately Si‐doped GaAsN.…”