EXCITON LOCALIZATION AND INTERISLAND EXCITON DIFFUSION IN INTERRUPTED-GROWTH GAAS-ALAS QUANTUM-WELL

We present a study of the exciton localization and the interisland exc iton diffusion in interrupted-growth thin GaAs-AlAs quantum wells (QW) , by photoluminescence (PL). These quantum wells include extended mono layer hat regions. We have shown that, for a given position on the sam ple, the exciton localization is stronger in the wide well regions tha n in the narrow well regions. We have also developed a quantitative mo del, of independently distributed cylindrical holes at the AlAs/GaAs i nterface, to explain the evolution of the interisland exciton diffusio n as a function of temperature and have obtained the average value of the narrow regions extension and the ratio of the area of the wide reg ions to the area of the narrow regions. (C) 1998 Elsevier Science B.V. All rights reserved.