Auger-limited minority carrier lifetime in GeSn/SiGeSn quantum well

Abstract

A minority carrier lifetime of 2.7 ns is measured at 77 K for a GeSn/SiGeSn single quantum well using time-resolved photoluminescence, and subsequent analyses indicate that the lifetime is Auger-limited. The 77 K lifetime is evaluated as a function of stepwise dose of 63 MeV proton irradiation up to a fluence of 1.5 × 1012 p+/cm2 with no discernable reduction in the observed lifetime, which implies that the lifetime damage factor slope to 63 MeV proton irradiation is not greater than 2 × 10−5 cm2/s. Steady-state photoluminescence is used to evaluate the total luminescence output as a function of excitation, yielding a 2/3 power law slope consistent with Auger-limited recombination. The observed Auger-limited behavior is consistent with reports of high p-type background carrier concentration in these alloys. The temperature dependence of the steady-state photoluminescence spectra also provides the Einstein single oscillator model parameters for the ground state transition energy and Urbach energy of the GeSn quantum well.