CdSe Quantum Dots Embedded in a ZnCdSe Quantum Well:Towards Efficient Yellow Photoluminescence

摘要

This paper reports on studies of self-assembled CdSe quantum dot (QD) nanostructures grown byusing molecular beam epitaxy in a ZnCdSe quantum well (QW) embedded in ZnSe barriers, whichemit in the yellow spectral range (λ = 560 - 570 nm). An up to 180-meV long-wavelength shift ofthe photoluminescence peak energy, as compared to QDs of the same nominal thickness grown ina ZnSe matrix, was demonstrated. The reasons for that are a decrease in the barrier band gap andan increase in the exciton localization energy in CdSe QDs grown in a ZnCdSe QW. Transmissionelectron microscopy studies demonstrate an increase in the QD density along with the decreasingtheir lateral size and a narrowing of the size distribution.