RANDOM-PERIOD SUPERLATTICE QUANTUM-WELLS

We report a study of a novel quantum well structure, the random-period superlattice quantum well (RSLQW), consisting of an AlAs/GaAs superla ttice (SL) sandwiched between two AlGaAs layers, where the periods in the SL are intentionally randomized. Photoluminescence (PL) measuremen ts are performed to probe the optical properties of the RSLQW structur es. Theoretical calculations are employed to correlate the type of tra nsition and transition energy with the experimental observations. Phon on sidebands are identified in the PL spectra of RSLQWs, in which type II transitions are predicted by calculation results. Compared to the findings in periodic superlattice quantum wells, some RSLQWs show sign ificantly stronger PL signals. However, all the RSLQW samples exhibit larger degradation of radiative recombination efficiency with increasi ng temperature.