Solution‐Processable Large‐Area Black Phosphorus/Reduced Graphene Oxide Schottky Junction for High‐Temperature Broadband Photodetectors

Abstract 2D materials‐based broadband photodetectors have extensive applications in security monitoring and remote sensing fields, especially in supersonic aircraft that require reliable performance under extreme high‐temperature conditions. However, the integration of large‐area heterostructures with 2D materials often involves high‐temperature deposition methods, and also limited options and size of substrates. Herein, a liquid‐phase spin‐coating method is presented based on the interface engineering to prepare larger‐area Van der Waals heterojunctions of black phosphorus (BP)/reduced graphene oxide (RGO) films at room temperature on arbitrary substrates of any required size. Importantly, this method avoids the common requirement of high‐temperature, and prevents the curling or stacking in 2D materials during the liquid‐phase film formation. The BP/RGO films‐based devices exhibit a wide spectral photo‐response, ranging from the visible of 532 nm to infrared range of 2200 nm. Additionally, due to Van der Waals interface of Schottky junction, the array devices provide infrared detection at temperatures up to 400 K, with an outstanding photoresponsivity (R) of 12 A W −1 and a specific detectivity (D*) of ≈2.4 × 10 9 Jones. This work offers an efficient approach to fabricate large‐area 2D Schottky junction films by solution‐coating for high‐temperature infrared photodetectors.