Time-resolved photoluminescence and steady-state optical studies of GaInNAs and GaInAs single quantum wells

Time-resolved photoluminescence spectroscopy is used to investigate carrier dynamics of Ga1-xNyAs1-y (x similar to 0.33, y similar to 0.01) single quantum well (QW) structures. PL spectra measured as a function of temperature together with the PL decay times at wavelengths around and below the PL peak energy are used to determine de-trapping activation energies and time constants. The results are interpreted in terms of simultaneous thermal excitation of deep localized excitons to shallow localized states. According to the model, with increasing temperatures, localized excitons gain enough thermal energy to populate the free exciton states in quantum well with shorter lifetimes due to coherent nature of free excitons. In addition, at temperatures around and above 80 K, more non-radiative channels become available to compete with the radiative processes leading to shorter time constants. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.