【Domestic Papers】Hybrid mode for absorption enhancement in the Ga₂O₃ nanocavity photodetector with grating electrodes

      Researchers from the Xidian University have published a dissertation titled "Hybrid mode for absorption enhancement in the Ga₂O₃ nanocavity photodetector with grating electrodes" in Applied Optics.

Abstract

      Gallium oxide (Ga₂O₃) photodetectors have drawn increased interest for their widespread applications ranging from military to civil. Due to the inherent oxygen vacancy defects, they seriously suffer from trade-offs that make them incompetent for high-responsivity, quick-response detection. Herein, a Ga₂O₃ nanocavity photodetector assisted with grating electrodes is designed to break the constraint. The proposed structure supports both the plasmonic mode and the Fabry–Perot (F-P) mode. Numerical calculations show that the absorption of 99.8% is realized for ultra-thin Ga₂O₃ (30 nm), corresponding to a responsivity of 12.35 A/W. Benefiting from optical mechanisms, the external quantum efficiency (EQE) reaches 6040%, which is 466 times higher than that of bare Ga₂O₃ film. Furthermore, the proposed photodetector achieves a polarization-dependent dichroism ratio of 9.1, enabling polarization photodetection. The grating electrodes also effectively reduce the transit time of the photo-generated carriers. Our work provides a sophisticated platform for developing high-performance Ga₂O₃ photodetectors with the advantages of simplified fabrication processes and multidimensional detection.

DOI：https://doi.org/10.1364/AO.524563