NONRADIATIVE RECOMBINATION AND SATURATION OF TRAPS IN MULTIPLE INTRINSIC QUANTUM-WELLS

We have investigated the dependence of the continuous-wave photoluminescence on the laser intensity, which is affected by the trap saturation and the dominant nonradiative recombination in multiple intrinsic quantum wells. If the laser intensity is relatively low, the photoluminescence is proportional to the 1.5 power of the laser intensity. As the laser intensity increases, however, and above a critical intensity, the photoluminescence increases at a rate that is higher than square-law and finally approaches this dependence. This is the result of trap saturation. In order to examine the trap saturation in a more sensitive scale, we have calculated the dependence of the effective nonradiative decay time on the laser intensity. In addition, the laser-intensity dependences of the trapping efficiency and of the ratio of the electron and hole nonradiative decay times, have been determined for different ratios of the trapping and nonradiative recombination rates. The laser-intensity dependences of the electron and hole nonradiative decay times have also been determined.