自组织量子点光致荧光的温度依赖性  

Temperature Dependence of Photoluminescence in Self-assembled Quantum Dots

作　　者：邓浩亮[1] 姚江宏[2] 

机构地区：[1]天津工程师范学院数理系,天津300222 [2]南开大学物理科学学院光子学中心,天津300071

出　　处：《发光学报》2007年第1期109-113,共5页Chinese Journal of Luminescence

基　　金：天津工程师范学院科研基金(KJ2006-028)资助项目

摘　　要：自组织量子点光致荧光的温度依赖性研究,对于实现室温下高效的量子点光电器件有着非常重要的意义。而量子点中的载流子动力学过程将决定其光致荧光的温度依赖性。采用稳态速率方程模型模拟了自组织量子点中载流子动力学过程,并且考虑了量子点材料带隙随温度的变化;模拟了不同温度下自组织量子点的光致荧光光谱,并获得了光谱的积分强度、峰值能量及半峰全宽随温度的变化曲线。研究表明:模拟结果与已报道的实验数据符合得很好。由此可知,所采用的模型能够很好地反映自组织量子点中的载流子动力学过程。The study of the temperature dependence of photoluminescence （PL） in self-assembled quantum dots （QDs） is essentially important for the realization of room temperature efficient photonic devices. The temperature dependence of photoluminescence in self-assembled QDs will be directly determined by the temperature dependence of carrier dynamics process in self-assembled QDs. As the temperature increases, the carriers will thermal escape into the wetting layer （WL） 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. carrier will transfer between the ensemble of QDs with difference sizes when the temperature increases. The temperature dependence of carrier dynamics process in self-assembled QDs was simulated with the steady-state rate equation model of carrier dynamics. The model takes into account the temperature dependence of the energy band gap of QDs material. The PL spectra of self-assembled QDs at difference temperatures and the temperature dependence of integrated PL intensity, FWHM and peak position were obtained. The results show that the calculated temperature dependence of integrated PL intensity, FWHM and peak position is consistent with the experimental data reported before. The agreement between experimental data and model simulations suggests the description of the carrier dynamics process in self-assembled QDs by the steady-state rate equation model taking into account the temperature dependence of the energy band gap of self-assembled QDs material is viable.

关 键 词：自组织量子点 光致荧光 热逃逸 再俘获 

分 类 号：O472.3[理学—半导体物理] O482.31[理学—物理]