Chen Chien-Yu, Ni Chia-Chun, Wu Ruei-Nan, Kuo Sheng-Yang, Li Chia-Hao, Kiang Yean-Woei, Yang C C
Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, No. 1, section 4, Roosevelt Road, Taipei, 10617, Taiwan.
Nanotechnology. 2021 Apr 30;32(29). doi: 10.1088/1361-6528/abf775.
Rhodamine 6G (R6G) molecules linked CdZnSeS/ZnS green-emitting quantum dots (QDs) are self-assembled onto Ag nanoparticles (NPs) for studying the surface plasmon (SP) coupling effect on the Förster resonance energy transfer (FRET) process from QD into R6G. SP coupling can enhance the emission efficiency of QD such that FRET has to compete with QD emission for transferring energy into R6G. It is found that FRET efficiency is reduced under the SP coupling condition. Although R6G emission efficiency can also be enhanced through SP coupling when it is directly linked onto Ag NP, the enhancement decreases when R6G is linked onto QD and then the QD-R6G complex is self-assembled onto Ag NP. In particular, R6G emission efficiency can be reduced through SP coupling when the number of R6G molecules linked onto a QD is high. A rate-equation model is built for resembling the measured photoluminescence decay profiles and providing us with more detailed explanations for the observed FRET and SP coupling behaviors.
将罗丹明6G（R6G）分子连接到CdZnSeS/ZnS绿色发射量子点（QD）上，使其自组装到银纳米颗粒（NP）上，用于研究表面等离子体（SP）耦合效应在从量子点到R6G的福斯特共振能量转移（FRET）过程中的作用。SP耦合可以提高量子点的发射效率，使得FRET在将能量转移到R6G时必须与量子点发射竞争。研究发现，在SP耦合条件下FRET效率降低。尽管当R6G直接连接到银纳米颗粒上时，其发射效率也可以通过SP耦合得到提高，但当R6G连接到量子点上，然后将量子点-R6G复合物自组装到银纳米颗粒上时，这种提高会降低。特别是，当连接到一个量子点上 的R6G分子数量较多时，R6G的发射效率会通过SP耦合而降低。建立了一个速率方程模型来模拟测量的光致发光衰减曲线，并为观察到的FRET和SP耦合行为提供更详细的解释。
