Plasmonic hot-electron photodetection with quasi-bound states in the continuum and guided resonances

Abstract Hot electrons generated in metallic nanostructures have shown promising perspectives for photodetection. This has prompted efforts to enhance the absorption of photons by metals. However, most strategies require fine-tuning geometric parameters achieve perfect absorption, accompanied demanding fabrications. Here, we theoretically propose a Ag grating/TiO 2 cladding hybrid structure hot electron photodetection (HEPD) combining quasi-bound states continuum (BIC) and plasmonic electrons. Enabled quasi-BIC, can be readily achieved it is robust against change several structural due topological nature BIC. Also, show that guided mode folded into light cone introducing disturbance become resonance, which then gives rise narrow-band HEPD difficult high loss gold plasmonics. Combining quasi-BIC also realize multiband with near-perfect absorption. Our work suggests new routes light-harvesting nanosystems.