载流子热迁移对自组织量子点光致荧光的影响  

Effect of Thermal Carrier Transfer on Photofluorescence in Self-assembled Quantum Dots

作　　者：邓浩亮[1] 姚江宏[2] 贾国治[2] 徐章程[2] 

机构地区：[1]天津工程师范学院 数理系,天津300222 [2]南开大学 泰达应用物理学院,天津300457

出　　处：《发光学报》2007年第5期720-723,共4页Chinese Journal of Luminescence

基　　金：天津工程师范学院科研基金(KJ2006-028)

摘　　要：自组织量子点光致荧光的温度依赖性研究对实现高效的量子点光电器件有着非常重要的意义,而量子点中载流子的动力学过程会对量子点光致荧光产生直接影响。采用稳态速率方程模型,在考虑了自组织量子点中载流子热迁移的情况下,模拟获得了不同温度下自组织量子点的光致荧光光谱,并着重研究了三组具有不同基态能量的量子点的光致荧光强度随温度的变化。研究表明,随着温度升高,基态能量较高的量子点光致荧光强度减弱,而基态能量较低的量子点光致荧光强度则增强,当温度达到一定值时,所有量子点的光致荧光都将发生热猝灭。The study of the temperature dependence of photofluorescence in self-assembled quantum dots （QDs） is essentially important for the realization of room temperature efficient photoeleetronic devices. The temperature dependence of photofluorescence of self-assembled QDs will be directly determined by the carrier dynamics process in self-assembled QDs. As the temperature increases, the carrier will be thermal excited into the wetting layer from the ground states of an ensemble of QDs with difference sizes and then some of them will be recaptured by other QDs, i.e. thermal carrier transfer will take place between the ensemble of QDs with difference sizes when the temoerature increases. In this paper, the temperature dependence of the photofluorescence of self-assembled QDs was simulated by using a steady-state rate equation model which takes into account the carrier thermally transfer effect in self- assembled quantum dots. The temperature dependence of photofluorescence intensity of three QDs groups with different ground state energy was emphatically investigated. The results show that, with the temperature in- creasing, the photofluorescence intensity of QDs with lower ground state energy becomes stronger while the photofluorescence intensity of QDs with higher ground state energy becomes weaker, and when the temperature reaches a certain value, the thermally quenching of the photofluorescence of all QDs will take place.

关 键 词：自组织量子点 载流子 热迁移 光致荧光 

分 类 号：O472.3[理学—半导体物理] O482.31[理学—物理]