Aluminum Nanoparticle-Enhanced a-Ga 2 O 3 Solar-Blind UV Photodetectors with High-Performance via Localized Surface Plasmon Resonance

Gallium oxide (Ga₂O₃), as an emerging ultra-wide-bandgap semiconductor materials, has demonstrated significant potential in solar-blind ultraviolet photodetection. This study prepared aluminum nanoparticles (NPs) to significantly improve the performance of amorphous Ga₂O₃ (a-Ga₂O₃) metal-semiconductor-metal (MSM) solar-blind ultraviolet photodetectors. Under a 10 V bias voltage, the Al-NPs/a-Ga₂O₃ device achieve a peak responsivity (R) of 2.24 × 10₃ A W^-1, an external quantum efficiency (EQE) of 1.1 × 10⁶ %, and a specific detectivity (D*) of 1.4 × 10¹² Jones, corresponding to improvements of 597 %, 1867 %, and 611 %, respectively, compared to pristine a-Ga₂O₃ photodetectors without Al-NPs. These enhancements are mainly ascribed to the localized surface plasmon resonance (LSPR) effect generated by the Al-NPs, which effectively enhances the light absorption and carrier excitation, thereby improving the ultraviolet signal detection capability of the device. This work provides a simple, low-cost and easily reproducible method that offers new ways and possibilities to optimize the performance of optoelectronic devices.