Enhanced performance of solar-blind photodetector of hexagonal boron nitride with bottom-contact electrodes

A deep ultraviolet photodetector has wide applications in both military and civil fields, such as the missile early warning system, transparent wireless communication, environmental monitoring, and so on. Because of its wide bandgap, hexagonal boron nitride (h-BN) has been envisioned to be a promising material for deep ultraviolet photodetectors. In this work, we have synthesized high-quality h-BN crystals using the flux growth method at atmospheric pressure. Based on the thin-layered h-BN prepared by mechanical exfoliation, two types of solar-blind photodetectors, with either top-contact or bottom-contact electrodes, were fabricated. It is found that the device with bottom-contact electrodes exhibits excellent performance in the specific detectivity exceeding 3.68 × 108 Jones (cm Hz1/2 W−1) at 215 nm. Moreover, the photodetectors have a cutoff wavelength at about 270 nm, which demonstrates that the device can be an ideal candidate for a solar-blind photodetector.