In this work, square nanopore arrays were developed on the surface of β-Ga2O3 microflakes using focused ion beam (FIB) etching, and solar-blind photodetectors (PDs) were fabricated based on the β-Ga2O3 microflakes with square nanopore arrays. The β-Ga2O3 microflake-based device was transformed from a gate voltage depletion mode to an oxygen depletion mode by FIB etching. The developed device exhibited excellent solar-blind PD performance with extremely high responsivity (1.8 × 105 at 10 V), detectivity (3.4 × 1018 Jones at 10 V), and light-to-dark ratio (9.3 × 108 at 5 V) as well as good repeatability and excellent stability. The intrinsic mechanism responsible for this performance was then systematically discussed. This work opens up a new avenue for the fabrication of high-performance β-Ga2O3-based low-dimensional PDs with high reproducibility by employing the FIB etching process.
Keywords: focused ion beam; oxygen depletion; persistent photoconductivity; solar-blind photodetector; square nanopore arrays; β-Ga2O3.