Spectral characteristics of surface-plasmon–enhanced photoluminescence in nanocrystalline SiC films
College of Physics Science and Technology, Hebei University - Baoding, 071002, China
Corresponding author: firstname.lastname@example.org
Accepted: 17 February 2010
Multilayer structures of nanocrystalline (nc-) SiC/silicon nitride spacer/Ag island films were designed by varying the spacer thickness, and the spectral characteristics of surface-plasmons (SPs)–enhanced photoluminescence (PL) in nc-SiC films have been investigated. The optical transmission spectra show that there are two SPs resonant optical absorption bands in the out-of-plane and in-plane modes for the Ag island film on the sample surface. While PL quenching occurred for the sample with the thinnest spacer, the maximum PL enhancement for nc-SiC is achieved when the thickness of the spacer is suitable, suggesting that the SP enhancement can dominate over nonradiative energy dissipation by varying the spacer thickness. In the case of PL enhancement, the PL excitation spectrum shows an enhancement peak at the resonant wavelength of the out-of-plane mode of SPs, indicating that the excitation enhancement in nc-SiC films occurs due to the incident-light resonant coupling with out-of-plane SPs. Whereas, the increased PL decay rate is observed in the temporal PL spectrum, implying that the SPs scattering enhancement in the nc-SiC film is induced by in-plane SP resonant coupling. In the case of PL quenching, although an enhancement factor less than 1 is observed in the PL excitation spectrum, an increased light emission decay rate is also revealed in the temporal PL spectrum, which indicates that the nonradiative energy dissipation of light emission in the Ag island film is the main coupling mechanism when the spacer is too thin.
PACS: 78.55.-m – Photoluminescence, properties and materials / 68.65.Ae – Multilayers
© EPLA, 2010