Alloy disorder effects on the room temperature optical properties of Ga1-xInxNyAs1-y quantum wells

The effect of alloy disorder on optical density of states and average room-temperature carrier statistics in Ga1-xInxNyAs1-y quantum wells is discussed. A redshift between the peak of the room-temperature photoluminescence and the surface photovoltage spectra that systematically increases with nitrogen content y is observed. The relationship between this Stokes shift and the absorption linewidth in different samples suggests that the photoexcited carriers undergo a continuous transition-from quasithermal equilibrium with the lattice to complete trapping by quantum dot like potential fluctuations-with increase in nitrogen fraction. The "electron temperatures" inferred from photoluminescence spectra are consistent with this interpretation. (c) 2006 American Institute of Physics.