Temperature-dependent resonance energy transfer from CdSe–ZnS core–shell quantum dots to monolayer MoS2

Abstract

We investigated the temperature-dependent resonance energy transfer (ET) from CdSe–ZnS core–shell quantum dots (QDs) to monolayer MoS2. QDs/MoS2 structures were fabricated using a spin-coating method. Photoluminescence (PL) spectra and decay curves of the QDs/MoS2 structures were measured in the temperature range of 80−400 K. The results indicate that the PL intensity of the QDs decreased approximately 81% with increasing temperature, whereas that of the MoS2 increased up to a maximum of 78% at 300 K because of the combined effect of thermal quenching and the ET in the QDs/MoS2 structures. The ET efficiency and ET rate also exhibited similar variation trends, both increased with increasing temperature from 80 to 260 K and then decreased until 400 K, resulting in a maximum ET efficiency of 22% and an ET rate of 1.17 ns–1 at ~260 K. These results are attributed to the varied distribution of the localized excitons and free excitons in the QDs/MoS2 structures with increasing temperature.