High-Sensitivity Amorphous Boron Nitride Vacuum Ultraviolet Photodetectors

Abstract

In this work, we fabricated a high-performance amorphous boron nitride vacuum ultraviolet (VUV) photodetector based on buried-electrode metal-semiconductor-metal structure for the first time. The device has a responsivity of 95.2 mA/W and an external quantum efficiency of up to 59.1% by improving carrier collection efficiency at 200 nm under a 20 V bias. At 300 K, the device exhibits a low dark current of 82 fA and a high specific detectivity of $8.3 \times 10^{\mathbf {{13}}}$ Jones. The response range between 163 nm and 215 nm covers the VUV spectrum and the VUV reject ratio against 254 nm and 450 nm is $4.2 \times 10^{\mathbf {{4}}}$ and $7.2 \times 10^{\mathbf {{7}}}$ , respectively. Even at 500 K, the device exhibits a dark current of only 1.2 pA and high responsivity, demonstrating excellent long-term stability and reliability. Furthermore, an ${8} \times {8}$ -pixel array composed of the photodetectors achieved stable and rapid (< 1 ms) VUV imaging. These findings demonstrate the outstanding performance of the photodetector and the potential applications of combining buried electrode structures with other ultra-wide bandgap semiconductors.