Enhancing Solar-Blind Photodetectors with Ga₂O₃ Thin Films Using Pt Nanoparticles

Due to their ultra-wide bandgap and brilliant chemical stability, gallium oxide (Ga2O3) is considered one of the most promising materials for solar-blind photodetectors. However, the preparation of high-performance solar-blind photodetectors based on a low-cost Ga2O3 thin film still remains a great challenge. In this work, β-Ga2O3 thin films with nanoscale thickness have been prepared on a sapphire substrate by a facile and effective sol–gel spin-coating method. At the same time, the effect of local surface plasmon resonance (LSPR) is introduced by fabrication of Pt nanoparticles (NPs) in order to improve the optoelectronic performance of photodetectors based on polycrystalline Ga2O3. By adding Pt NPs, significant performance enhancement has been observed in terms of on/off ratio, responsiveness, detectivity, and external quantum efficiency by 618.7%, 66.7%, 390.7%, and 266.7%, respectively, reaching a comparable level to certain single-crystalline devices.