Enhanced Efficiency of a Fluorescing Nanoparticle with a Silver Shell
Spontaneous emission (SE) rate and the fluorescence efficiency of a bare fluorescing nanoparticle (NP) and the NP with a silver nanoshell are analyzed rigorously by using a classical electromagnetiC approach with the consideration of the nonlocal effect of the silver nano-shell. The dependences of the SE rate and the fluorescence efficiency on the core-shell structure are carefully studied and the physical interpretations of the results are addressed. The results show that the SE rate of a bare NP is much slower than that in the infinite medium by almost an order of magnitude and consequently the fluorescence efficiency is usually low. However, by encapsulating the NP with a silver shell, highly efficient fluorescence can be achieved as a result of a large Purcell enhancement and high out-coupling efficiency (OQE) for a well-designed core-shell structure. We also show that a higher SE rate may not offer a larger fluorescence efficiency since the fluorescence efficiency not only depends on the internal quantum yield but also the OQE.
Wallace C. H. Choy Xue-Wen Chen Sailing He
Department of Electrical and Electronic Engineering,University of Hong Kong,Pokfulam Road,Hong Kong Department of Electrical and Electronic Engineering,University of Hong Kong,Pokfulam Road,Hong Kong Centre for Optical and Electromagnetic Research,Zhejiang University,Zhijingang campus,Hangzhou 31005
国际会议
The 8th China International Nanoscience and Technology Symposium(2009第八届中国国际纳米科技湘潭研讨会Cinsts09)
湖南湘潭
英文
1-4
2009-10-23（万方平台首次上网日期，不代表论文的发表时间）