Impact of carrier localization on the photoluminescence characteristics of (Ga,In)(N,As) and (Ga,In)(N,As,Sb) quantum wells

Abstract

Using photoluminescence (PL) spectroscopy, we carry out a comparative study of the optical properties of (Ga,In)(N,As) and (Ga,In)(N,As,Sb) quantum wells. The incorporation of Sb into (Ga,In)(N,As) results in a reduced quantum efficiency at low temperatures but an improved one at room temperature (RT). A PL line shape analysis as well as the temperature dependence of the PL peak energy reveals the existence of band-tail localized states in both material systems. The carrier localization energy is larger for (Ga,In)(N,As,Sb) than for (Ga,In)(N,As), leading to a longer radiative lifetime and thus a reduced quantum efficiency at low temperatures for the former material. The thermal quenching of the quantum efficiency is analyzed by a rate equation model, which shows that the density of nonradiative centers is reduced in (Ga,In)(N,As,Sb) resulting in an enhanced quantum efficiency at RT.