The deep ultraviolet detector based on BN/Au and BN/Al interfaces

Boron nitride (BN) is suitable for ultraviolet (UV) photodetection with its wide bandgap and high absorption coefficient. The research on fabrication process and performance optimization is urgent with the development of UV detection technology. In this work, the band structure, work function, charge distribution and transfer, and optical absorption coefficients of BN/Au and BN/Al interfaces are calculated based on the density functional theory. The results show that the BN monolayer gets more charges with the influence of Au. The charge transfer is 0.025e and 0.015e for BN/Au and BN/Al. The absorption coefficients of BN/Au is higher than that of BN/Al in the DUV region, which enhances the light absorption of BN. In addition, BN/Au and BN/Al DUV detector is fabricated by dry transfer method. The highest photo-dark current ratio (PDCR) of 115.04 and 29.09 are obtained for BN/Au and BN/Al at an optical power density of 1.21 mW/cm² (V_bias=10 V). The responsivity (R) and detectivity (D*) is up to 0.70μA/W and 1.55 × 10⁸Jones for the BN/Au. The rise and fall times (T_r/T_f) are 0.12 s and 0.11 s, respectively. The DUV detector is fabricated with easy process, low cost and fast response. This provides theoretical support and technical reference for the next generation of high-performance devices.