Atomic arrangement and emission properties of GaAs(In, Sb)N quantum wells

Fine structure related to different types of atomic arrangements (short-range order, phase separation and quantum dots) was observed in high-spatial-resolution low-temperature photoluminescence (PL) spectra of GaAsInN, GaAsSbN and GaAsInSbN quantum wells (QWs) containing ~1.5% N and emitting at 1.2–1.3 µm. Using photoreflectance and temperature-dependent PL spectroscopy, we measured the activation energies and band-tail width of localized states, associated with different atomic arrangements, to be 5–66 meV. We found that the emission intensity in these GaAs(In, Sb)N QWs weakly depends on carrier localization and that it is limited at cryogenic temperatures by exciton scattering by N interstitials, while at room temperature it is limited by an intrinsic non-radiative recombination channel having activation energy of ~60 meV and capture time between 0.01 and 1 ps.