Black Arsenic Phosphorus Mid-Wave Infrared Barrier Detector with High Detectivity at Room Temperature.

The barrier structure has been designed to enhance the operating temperature of the infrared detector, thereby improving the efficiency of collecting photogenerated carriers and reducing dark current generation, without suppressing the photocurrent. However, the development of barrier detectors using conventional materials is limited due to the strict requirements for lattice and band matching. In this study, we have designed a high-performance unipolar barrier detector utilizing a black arsenic phosphorus/molybdenum disulfide/black phosphorus van der Waals heterojunction. Our device exhibits a broad response bandwidth ranging from visible light to mid-wave infrared (520 nm to 4.6 μm), with a blackbody detectivity of 2.7 × 10 10 cmHz -1/2 W -1 in the mid-wave infrared range at room temperature. Moreover, the optical absorption anisotropy of black arsenic phosphorus enables polarization resolution detection, achieving a polarization extinction ratio of 35.5 at 4.6 μm. We have successfully demonstrated mid-wave infrared imaging of the device at room temperature, highlighting the significant potential of barrier devices based on van der Waals heterojunctions in mid-wave infrared detection. This article is protected by copyright. All rights reserved.