|Search for content and authors|
Surface enhanced size-dependent photoluminescence from silver nanoparticles in silica matrix
|Oleg Yeshchenko 1, Igor Dmitruk 1, Alexandr Alexeenko 2, Mykhaylo Losytskyy 1, Andriy V. Kotko 3, Anatoliy Pinchuk 4|
1. Physics Department, National Taras Shevchenko Kyiv University, Akad.Glushkov prosp.2, Kiev 03127, Ukraine
We report the strong photoluminescence from the spherical silver nanoparticles with sizes of 8 – 30 nm incorporated in silica matrix. Two bands were observed in PL spectra of Ag nanoparticles. The high energy band was observed only in the samples with smallest 8 and 11 nm Ag nanoparticles. It was attributed to the radiative recombination of the electrons in sp conduction band of silver with holes in d valence band. The low energy band was observed in all the samples with the nanoparticles of sizes of 8 – 30 nm. The intensity of PL spectrum was found to increase with decrease of nanoparticle size. The quantum yield of the photoluminescence was measured. It was found to be maximum in smallest 8 nm Ag nanoparticles, namely about 10-2 that is in 108 times higher than in bulk silver. We performed the calculation of the theoretical photoluminescence spectra of Ag nanoparticles with various sizes working in the frame of the model1 of the local field enhancement by surface plasmons in Ag nanoparticles. The calculations is in good agreement with the experimental results that proves that the strong size dependent enhancement of the luminescence from Ag nanoparticles is the results of the enhancement of the electric fields of exciting and outgoing photons due to coupling of photons to surface plasmon resonance in Ag nanoparticle.
1. Boyd, G.T., Yu, Z.H., Shen, Y.R., Phys. Rev. B 33, 7923-7936 (1986).
Presentation: Poster at E-MRS Fall Meeting 2009, Symposium I, by Oleg Yeshchenko
See On-line Journal of E-MRS Fall Meeting 2009
Submitted: 2009-04-27 17:02 Revised: 2009-06-07 00:48