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.