A Synergistic Postprocessing Strategy for Enhancing Photoresponse Performance of In/Ni/Ga ₂ O ₃ /in Photodetector

Postprocessing technology is one of the crucial technical strategies for enhancing device performance. By appropriately selecting and using postprocessing techniques synergistically, the intrinsic potential of materials in device applications can be better unleashed. In this work, argon (Ar) plasma treatment and the vacuum high-temperature annealing process are used separately and synergistically for the posttreatment of Ga2O3and Ni/Ga2O3films. The results indicate that the coordinated postprocessing operations facilitate the introduction of more oxygen vacancy defects on the film surface, while simultaneously achieving a clean film surface and improving the bulk crystal quality, which is beneficial for UV light absorption, photogenerated carrier capture, and rapid carrier transport and collection, enhancing the photodetection performance. In addition, the surface Ni layer is modulated via postprocessing operations, inducing a lower dark current and a shorter rise time due to the formation of a depletion layer. Ultimately, the photoresponse performance of the Ga2O3photodetector (PD) can be effectively improved with the photo-to-dark current ratio (PDCR) significantly increased from 11 to 11 475, providing a new strategy and valuable insights for the optimization of future Ga2O3-based PDs.