A high-performance UV photodetector with superior responsivity enabled by a synergistic photo/thermal enhancement of localized surface plasmon resonance

Abstract

In this paper, we propose a new strategy to enhance the photoelectric performance of ultraviolet (UV) photodetectors by exploiting a synergistic photo-thermal effect which is induced by a localized surface plasmon resonance. We demonstrate that a W₁₈O₄₉ plasmonic semiconductor is able to improve the performance of target photodetectors as a result of a localized surface plasmon resonance, which increases light absorption, enhances the photothermal effect to deliver an increased photocurrent, and provides photo-induced “hot electrons” to limit carrier depletion over prolonged light illumination. Consequently, a UV photodetector based on W₁₈O₄₉/TiO₂ nanofibers is shown to exhibit an excellent photodetection performance with a high responsivity of up to 1.6 × 10⁴ A W⁻¹, which is five times greater than that of the pure TiO₂ analogue and greatly exceeds those of the TiO₂-based photodetectors reported to date.