Effect of growth conditions on optical properties of CdSe/ZnSe single quantum dots

摘要

In this work, we have investigated the optical properties of two samples ofCdSe quantum dots by using submicro-photoluminescence spectroscopy. The effectof vicinal-surface GaAs substrates on their properties has been also assessed.The thinner sample, grown on a substrate with vicinal surface, includes onlydots with a diameter of less than 10 nm (type A islands). Islands of an averagediameter of about 16 nm (type B islands) that are related to a phase transitionvia a Stranski-Krastanow growth process are also distributed in the thickersample grown on an oriented substrate. We have studied the evolution oflineshapes of PL spectra for these two samples by improving spatial resolutionthat was achieved using nanoapertures or mesa structures. It was found that theuse of a substrate with the vicinal surface leads to the suppression ofexcitonic PL emitted from a wetting layer.