测量了CdSe/ZnS (3 ML)核/壳结构及CdSe/CdS (3 ML)/ZnCdS (1 ML)/ZnS (2 ML) 核/多壳层结构量子点在80～460 K范围内的光致发光光谱, 研究了壳层结构对CdSe量子点发光热稳定性的影响。详细地分析了CdSe量子点的发光峰位能量、线宽和积分强度与温度之间的关系, 发现CdSe量子点的发光热稳定性依赖于壳层结构。CdS/ZnCdS/ZnS多壳层结构包覆CdSe量子点在低温和高温部分的热激活能均大于ZnS壳层包覆的CdSe量子点, 具有更好的发光热稳定性。此外, 在300-460-300 K加热-冷却循环实验中, CdS/ZnCdS/ZnS多壳层结构包覆CdSe量子点的发光强度永久性损失更少, 热抵御能力更强。

The photoluminescence (PL) spectra of CdSe/ZnS (3 ML) core/shell quantum dots (QDs) and CdSe/CdS (3 ML)/ZnCdS (1 ML)/ZnS (2 ML) core/multishell QDs were measured in the temperature range from 80 to 460 K by steady-state PL spectroscopy. The temperature dependence of PL energy, linewidth, and intensity for CdSe QDs was investigated. It is found that the thermal stability of CdSe QD emissions is significantly dependent on the shell structure. The thermal activation energy of CdSe/CdS/ZnCdS/ZnS core/multishell QDs is higher than that of CdSe/ZnS core/shell QDs. Furthermore, the stability of CdSe QDs at high temperature was also examined through heating-cooling cycling experiments. The permanent loss of PL intensity for CdSe/CdS/ZnCdS/ZnS core/multishell QDs is smaller than that of CdSe/ZnS core/shell QDs.