Boosting β-Ga₂O₃ Solar-Blind Detector via Highly Photon Absorbance and Carrier Injection by Localized Surface Plasmon Resonance

In this letter, an improved Ga2O3 solar-blind photodetector is introduced. Using the Ga2O3 thin film grown by metalorganic chemical vapor deposition, the localized surface plasmon resonance enhanced solar-blind photo-response is discussed in view of light absorbance and carrier injection. By introducing Pt nanoparticles to decorate the Ga2O3 photodetector, the responsivity, detectivity, and external quantum efficiency are increased from 0.13 A/W, $4.8\times 10^{{11}}$ Jones and 65% to 4.49 A/W, $8.66\times 10^{{12}}$ Jones and 2196%, respectively. Basically, optimal Pt nanoparticles could resonance with Ga2O3 at around 250 nm light irradiation, exciting the excess electrons to inject into the Ga2O3 thin film; during this process, the photon absorbance and effective carrier injection render the enhancement of detector, so long as the photon energy could generate the electron-hole pairs; due to the light-induced non-equilibrium state. Meanwhile, the absorbance peak resonance enhanced the interaction between photons and Ga2O3. As an effective pathway to boost solar-blind photodetector, this work provides a simple and feasible route to improve the photo-response based on wide bandgap semiconductor Ga2O3.