Luminescence line shape broadening mechanisms in GaInAs/AlInAs quantum wells

Abstract

GaInAs/AlInAs single quantum wells have been grown lattice matched to InP substrates by molecular beam epitaxy. The quantum well thicknesses ranged from 15 to more than 100 Å. The low-temperature photoluminescence exhibited a monotonically increasing spectral linewidth with decreasing well thickness. Of the several possible broadening mechanisms of the quantum well photoluminescence, two mechanisms were found to dominate: one mechanism for thin wells and one for thick wells. Quantum wells thicker than 50 Å were found to have their low-temperature photoluminescence spectra broadened primarily by a transfer of electrons from the AlInAs cladding layers into the GaInAs quantum well. Wells thinner than 50 Å had their photoluminescence broadened mainly by interface roughness.