High‐Sensitive and Fast Speed UV Photodetector Based on HfSe₂/InSe Heterostructure

Abstract

The type‐II band‐aligned van der Waals (vdW) heterostructures are favorable for photocarrier separation and are often used for designing high‐performance photodetectors. Inspired by this, a metal‐mirror electrode enhanced HfSe2‐InSe vdW heterostructure photodetector is designed and demonstrated excitement performance in UV light detection. It is demonstrated the moderate bandgap heterostructure can be configured as a high‐performance UV photodetector with excellent light on/off ratio of 106, high photoresponsivity of 47.3 AW−1, competitive high specific detectivity of 3.2 × 1012 cmHz1/2W−1 and very low noise equivalent power of 2.8 × 10−16 WHz−1/2. Notably, the photoresponse speed of the device is very fast, with a rise time of 4.1 µs and a decay time of 5.4 µs. The results indicate that 2D HfSe2‐InSe vdW heterostructure possesses great potential applications in UV photodetection.