INVESTIGATION OF THE TEMPERATURE-DEPENDENT RECOMBINATION PROCESSES INPERIODIC 4-NARROW-ASYMMETRIC-COUPLED-QUANTUM-WELL STRUCTURES

Continuous-wave intensity-dependent photoluminescence spectra of perio dic four-narrow-asymmetric-coupled-quantum-well structures were measur ed at different temperatures. Above 215 K, the photoluminescence depen ds linearly on high pump laser intensities and quadratically on low pu mp laser intensities. This is due to the competition between radiative recombination, and nonradiative recombination of carriers at excitati on intensity saturable deep traps. Below 215 K the trapping becomes ne gligible and the photoluminescence is linearly proportional to all las er intensity levels; radiative recombination dominates. Based on this transitional (from quadratic to linear) behavior of the photoluminesce nce and our simple theory, the transition intensity, the effective non radiative decay time of the carriers, and the photoluminescence quantu m efficiency have been determined as a function of temperature.