Temperature dependence of photoluminescence spectra of self-organized CdSe quantum dots

Abstract

We have investigated temperature dependence of photoluminescence (PL) spectra of self-organized CdSe quantum dots (QDs) as compared to a ZnCdSe quantum well (QW). PL integrated intensity of self-organized CdSe QDs gradually increases up to 60 K, indicating the strain-induced prevention of carrier diffusion. Spectral linewidth of QDs is almost constant below 150 K, and linearly increases above 150 K. We have also performed deconvolution from the spectrum above 150 K to two peaks. Linewidth of the fitted peak of lower energy side is independent of temperature even above 150 K, which shows the feature of QD. On the other hand, linewidth of the fitted peak of higher energy side increases as temperature rises. The result suggests the existence of a QW-like continuous state lying over QD state.