Ru Nanograting-EnhancedGa₂O₃ Solar-Blind Photodetectors via LocalizedSurface Plasmon Resonance

Abstract

Plasmonic nanoarray structures offer great potential for high-performance photodetectors due to their excellent ability to effectively trap light. In this work, Ga₂O₃ solar-blind photodetectors with Ru nanogratings were designed, precisely fabricated, and characterized systematically for the first time. The Ru nanograting through localized surface plasmon resonance significantly concentrates the optical field, reduces the transmittance, and enhances light–matter interactions, ultimately increasing absorbance. Integrating the Ru nanograting into Ga₂O₃ films induces a blue shift in the response peak, from 245 nm in Ga₂O₃ films to 215 nm. Meanwhile, the peak current rises dramatically from 4.9 × 10^–11 to 1.3 × 10^–9 A. The peak responsivity and specific detectivity are increased by 4.9 × 10² times and 6.8 × 10² times, respectively. This modification also accelerates the response speed, with τ_r and τ_d, of 0.96/0.14 s, notably shorter than the 1.57/0.47 s in Ga₂O₃ films. The mechanisms underlying strengthened absorbance and light–matter interactions are comprehensively explained through both simulated and experimental data. This work lays the theoretical and experimental groundwork for future high-performance Ga₂O₃-based photodetectors.