ZnCuInS/ZnS量子点光致发光温度依赖性研究

Investigation of Temperature-Dependent Photoluminescence of ZnCuInS/ZnS Quantum Dots

ZnCuInS/ZnS量子点是一种无重金属“绿色”半导体纳米材料。制备出了直径为2.9nm的ZnCuInS/ZnS核壳量子点。从ZnCuInS/ZnS量子点的吸收及光致发光光谱中可以看到,量子点的斯托克斯位移为410meV。这样大的斯托克斯位移表明,ZnCuInS/ZnS量子点的复合机制与缺陷能级有关。研究并计算了在辐射及非辐射驰豫过程的（Huang-Rhys）因子及平均声子能量。结果表明在50~373K范围内,能量带隙的变化以及光致发光光谱的增宽是分别由光从能带边缘向缺陷能级跃迁及载流子声子耦合导致的。

In the paper, ZnCuInS/ZnS core/shell/shell quantum dots were prepared with the particle size of 2.9 nrn. The PL band showed large Stokes shifts over 410 meV, such large Stokes shifts indicated that the emission should be ascribed to the defect-related recombination. A time-resolved photoluminescence spectra data was obtained by three index fitting three tran sition coexist, the ZnCMnS/ZnS was a characteristic of three dominating transitions from band energy level to level, from the conduction band energy level to the acceptor level, and from donor level to acceptor level. Research and calculate radia- tive and nonradiative relaxation processes, from the （Huang-Rhys） factor and the average phonon energy were calculated. The results show that in the temperature range 50~373 K, changes in energy band gap and photoluminescence spectra were broadening was due to a defect level with the edge of caused, respectively. the optical transitions and carriers with acoustic phonon coupling