Preparation of AgBiS2 thin films with vapor-assisted solution method for flexible near-infrared photodetectors

Here, we propose a simple low-temperature solution spin-coating combined with a vacuum-assisted chemical vapor deposition method to fabricate AgBiS₂ thin films for flexible near-infrared (NIR) photodetectors. Using a simple metal/semiconductor/metal device as a demonstration, the as-prepared AgBiS₂-based flexible NIR photodetectors (NPDs) exhibit a high linear dynamic range of 103.6 dB. The photodetectors exhibit high responsivity from UV to NIR with a maximum sensitivity of 16.9 A W⁻¹ and a detectivity of 2.31 × 10¹¹ Jones at a bias voltage of 1 V under 850 nm illumination. Meanwhile, after 2700 bending cycles, the flexible devices retain strong bending stability with a negligible decrease in photocurrent. We also built a hemispherical apparatus based on the AgBiS₂ flexible NPD to demonstrate its wide-angle detection capability.