Determination of the Minimum Island Size for Full Exciton Localization Due to Thickness Fluctuations in Zn1-xCdxSe Quantum Wells.

摘要

Atomic layer fluctuations of the thickness of quantum wells (QWs) are one of the causes of exciton localization. Here we present the results of the determination of the minimum lateral dimensions of islands formed by thickness fluctuations in Zn(1)(-x)Cd(x)Se QWs which produce full exciton localization. We have calculated the localization energy of excitons in the frame of the factorized-envelope approximation. We found that the excitons are well localized in the islands of the QW when their dimensions are larger than (caret)15 times the exciton Bohr radius. This result allows us to evaluate the quality of the QW structure and interpret the photoluminescence characteristics of QWs.