【Device Papers】Enhancing solar-blind UV photodetection of Ga₂O₃-based photodetectors by using AlN passivation layer

      Researchers from the Liaoning Normal University have published a dissertation titled "Enhancing solar-blind UV photodetection of Ga₂O₃-based photodetectors by using AlN passivation laye" in Physica B: Condensed Matter.

Abstract

      In this work, Ga₂O₃ thin films were deposited on c-plane sapphire and Si substrates via radio-frequency magnetron sputtering at room temperature. AlN passivation layers of varying thicknesses (0–15 nm) were then added, followed by the deposition of transparent ITO interdigitated electrodes, producing MISIM (metal-insulator-semiconductor-insulator-metal) photodetectors with enhanced solar-blind UV response. The device with a 10 nm AlN layer achieved a responsivity of 8.4 A/W, an external quantum efficiency (EQE) of 4108 %, and a photocurrent-to-dark current ratio (PDCR) of 8.4 × 10⁴ at 10 V bias. Rather than reducing dark current, this improvement stems from increased photocurrent via photo-assisted Fowler-Nordheim tunneling. The passivation layer diminished defects at the electrode/semiconductor interface, enhancing electron-hole pair separation and further boosting the photodetection performance. These results demonstrate the critical role of interface engineering in optimizing Ga₂O₃-based photodetectors and highlight the potential of AlN passivation for deep-UV applications.

DOI：

https://doi.org/10.1016/j.physb.2025.417651