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

摘要

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(ln, 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.