Radiative and nonradiative recombination processes in lattice-matched (Cd,Zn)O/(Mg,Zn)O multiquantum wells

Time-resolved photoluminescence studies have been performed on (Cd,Zn)O/(Mg ,Zn)O multiquantum wells, which are almost perfectly lattice matched (0.034 %), grown by laser molecular-beam epitaxy on a ScAlMgO4 substrate. Radiativ e recombination of excitons in the wells exhibits a significant spectral di stribution of times. This distribution was interpreted in terms of localiza tion of excitons by potential fluctuations due to alloy disorder and to wel l width and depth variations. The temperature dependence of the radiative l ifetime of excitons was deduced from the measurement of both the photolumin escence decay time and intensity. We found that the radiative lifetime incr eases linearly with temperature, showing a two-dimensional feature of excit ons in the quantum wells. (C) 2000 American Institute of Physics. [S0003-69 51(00)01837-4].