Enhancement of Photoluminescence by Ag Localized Surface Plasmon Resonance for Ultraviolet Detection

For higher sensitivity in ultraviolet (UV) and even vacuum ultraviolet (VUV) detection of silicon-based sensors, a sandwich-structured film sensor based on Ag Localized Surface Plasmon Resonance (LSPR) was designed and fabricated. This film sensor was composed of a Ag nanoparticles (NPs) layer, SiO2 buffer and fluorescence layer by physical vapour deposition and thermal annealing. By tuning the annealing temperature and adding the SiO2 layer, the resonance absorption wavelength of Ag NPs matched with the emission wavelength of the fluorescence layer. Due to the strong plasmon resonance coupling and electromagnetic field formed on the surface of Ag NPs, the radiative recombination rate of the luminescent materials and the number of fluorescent molecules in the excited state increased. Therefore, the fluorescent emission intensity of the sandwich-structured film sensor was 1.10-1.58 times at 120-200 nm and 2.17-2.93 times at 240-360 nm that of the single-layer film sensor. A feasible method is provided for improving the detection performance of UV and VUV detectors.

Automated summary

A sandwich-structured film sensor based on Ag Localized Surface Plasmon Resonance (LSPR) was designed and fabricated for higher sensitivity in ultraviolet (UV) and vacuum ultraviolet (VUV) detection of silicon-based sensors. By tuning the annealing temperature and adding the SiO2 layer, the resonance absorption wavelength of Ag NPs was matched with the emission wavelength of the fluorescence layer, resulting in significantly improved detection performance. This study provides a feasible method for enhancing the detection performance of UV and VUV detectors.