扫描近场光学显微镜测量量子点团簇超辐射

用扫描近场光学显微镜的针尖照明模式对ZnSe量子点团簇进行精确定位测量,研究了量子点团簇的超辐射效应。在理论上根据Wannier激子超辐射模型阐述了量子点系统的超辐射发光机制;实验上用荧光光谱表征ZnSe量子点溶液的荧光性质,用扫描近场光学显微镜(SNOM)表征单个量子点团簇的超辐射光谱。结果表明,在Wannier激子超辐射模型中,量子点团簇辐射衰变率受到量子点团簇的大小和辐射光谱的共同影响,在实验上得出团簇的辐射衰变率随团簇尺寸的增加而增大,同时,不同尺寸的量子点团簇产生的辐射光谱也会对其产生影响,理论和实验的结合验证了激子超辐射的适用性。此研究结果可广泛用于生物传感器和光子器件等领域。

Measurement of Superradiance of Quantum Dots Cluster by Scanning Near-field Optical Microscope

The needle illumination mode of the scanning near field optical microscope(SNOM) is used to carry out the precise positioning measurement of the ZnSe quantum dots cluster and the superradiance effect of the quantum dots cluster is studied in this paper. The superradiance luminous mechanism of the quantum dots system is presented based on the Wannier exciton superradiance model. The fluorescence properties of ZnSe quantum dots solution are characterized by the fluorescence spectrum and the superradiance spectrum of single quantum dot clusters is characterized by SNOM experimentally. The results show that the radiation decay rate of the quantum dots cluster is affected by both the size of quantum dots cluster and the radiation spectrum. The radiation decay rate of the quantum dots cluster increases with the increase of the size of the quantum dots cluster, and the radiation spectrum generated by the quantum dots cluster with different size will affect the radiation decay rate. The applicability of the exciton superradiance is verified by both the theory and experiment. The results of this study can be widely used in biosensors and photonic devices and other fields.