Silicon Plasmonics for Enhanced Responsivity of Silicon Photodetectors in Deep-Ultraviolet Region

We report on the utilization of Si in plasmonics research, specifically targeting deep ultraviolet (DUV) applications. By incorporating periodic submicron gratings on a Si surface, we demonstrate a photoconductive Si detector with significantly enhanced responsivity to DUV light, which is achieved via surface plasmon resonance (SPR). Notably, even without a metal, the detector exhibits improved responsivity only under TM-polarized light, supporting the interpretation that Si excites SPR. Our demonstration not only validates the effectiveness of Si plasmonics for enhancing photodetector performance but also introduces innovative techniques with potential applications in various research fields.