Abstract

Based on our measurements of cw intensity-dependent photoluminescence (PL) excitation spectra of multiple narrow slightly asymmetric coupled quantum wells (ACQWs) at room temperature, strong saturation of interface traps has been observed similar to that reported in Ref. ¹. Each ACQW consists of two GaAs QWs of thicknesses of 1.8 nm and 2.1 nm separated by a 3 nm Al_{0 4}Ga_{0 6}As barrier. As laser intensity increases, PL intensity initially increases at a rate higher than that for a square-law dependence and finally approaches that dependence. This phenomenon can be attributed to a dominant nonradiative recombination at the interface traps undergoing a strong saturation with weak radiative recombination of free carriers. Intensity-dependent trapping efficiency and the ratio of electron and hole nonradiative decay times, and the ratio of trapping and nonradiative recombination rates have been determined from the experiment.

© 1992 Optical Society of America