ZnSe/ZnS量子点复合薄膜的非线性光学特性

Nonlinear Optical Properties of ZnSe/ZnS Quantum Dot Composite Films

本文通过直流射频技术和匀胶技术成功制备出了Ag/ZnSe/ZnS复合薄膜和PMMA/ZnSe/ZnS复合薄膜。通过表征手段观察了两种薄膜的形貌以并进行了元素分析。紫外可见吸收光谱显示,两种复合薄膜中各组成部分对于复合薄膜的吸收均有影响,由于Ag纳米薄膜具有等离激元效应,与纯量子点相比Ag/ZnSe/ZnS复合薄膜吸收强度明显提高。在800 nm波长,激发功率为300 nJ的开孔Z扫描测试中发现,两种薄膜的非线性吸收特性均表现出饱和吸收特性。通过计算非线性吸收系数(β)发现Ag/ZnSe/ZnS复合薄膜比PMMA/ZnSe/ZnS复合薄膜的非线性吸收系数高出十倍,说明Ag纳米薄膜可以更好的提高量子点非线性吸收特性。

In this paper, Ag/ZnSe/ZnS composite films and PMMA/ZnSe/ZnS composite films were successfully prepared by DC radio frequency technology and uniform gel technology. The morphology of the two films was observed by means of characterization and elemental analysis. UV-VIS absorption spectra shows that each components of the composite films have an effect on the absorption of the composite films. The absorption intensity of Ag/ZnSe/ZnS composite films was significantly higher than pure QDs due to the plasmon effect of Ag nanofilms. At 800 nm wavelength and 300 nJ excitation power, it is found that the nonlinear absorption characteristics of both films show saturated absorption characteristics. By calculating the nonlinear absorption coefficient (β), it is found that the nonlinear absorption coefficient of Ag/ZnSe/ZnS composite films are ten times higher than that of PMMA/ZnSe/ZnS composite films, indicating that Ag nano-films can better improve the nonlinear absorption characteristics of QDs.