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

We have investigated the dependence of the continuous-wave photolumine scence on the laser intensity, which is affected by the trap saturatio n and the dominant nonradiative recombination in multiple intrinsic qu antum wells. If the laser intensity is relatively low, the photolumine scence is proportional to the 1.5 power of the laser intensity. As the laser intensity increases, however, and above a critical intensity, t he photoluminescence increases at a rate that is higher than square-la w and finally approaches this dependence. This is the result of trap s aturation. In order to examine the trap saturation in a more sensitive scale, we have calculated the dependence of the effective nonradiativ e decay time on the laser intensity. In addition, the laser-intensity dependences of the trapping efficiency and of the ratio of the electro n and hole nonradiative decay times, have been determined for differen t ratios of the trapping and nonradiative recombination rates. The las er-intensity dependences of the electron and hole nonradiative decay t imes have also been determined.