【Device Papers】High-Performance Self-Powered Solar-Blind Ultraviolet Photodetector Based on GaN/κ-Ga₂O₃ Heterojunction

      Researchers from the Shandong University have published a dissertation titled "High-Performance Self-Powered Solar-Blind Ultraviolet Photodetector Based on GaN/κ-Ga₂O₃ Heterojunction" in Optical Materials.

Abstact

      Self-powered solar-blind ultraviolet photodetectors (SBPDs) based on Ga₂O₃ exhibit significant advantages in practical applications due to their high efficiency, low power consumption, and fast response speed. In this study, Sn-doped κ-Ga₂O₃ films were epitaxially grown on GaN/sapphire substrates using a cost-effective and environmentally friendly mist-chemical vapor deposition (Mist-CVD), enabling fabrication of a self-powered SBPD based on a GaN/κ-Ga₂O₃ heterojunction. At zero bias under 254 nm illumination with 500 μW/cm² optical power density, the device exhibited a photocurrent of 1.61 × 10⁻⁷ A, photocurrent-to-dark-current ratio of 2.78 × 10³, responsivity of 80.5 mA/W, external quantum efficiency of 39.38%, detectivity of 1.18 × 10¹² Jones, and rise/decay times of 660 ms/590 ms. This result substantially outperforms those of previously reported self-powered SBPDs based on either β-Ga₂O₃ or amorphous Ga₂O₃. The energy band alignment diagrams were constructed to elucidate the carrier transport mechanism in the self-powered SBPD based on the GaN/κ-Ga₂O₃ heterojunction. The incorporation of Sn substantially enhanced the separation efficiency of photogenerated carriers, consequently improving the photoelectric performance of the device. This study provides a promising strategy for fabricating high-performance Ga₂O₃-based SBPDs.

DOI：

https://doi.org/10.1016/j.optmat.2026.117843