High-Performance and Stable Sb2S3 Thin-Film Photodetectors for Potential Application in Visible Light Communication

Photodetectors(PDs) are critical parts of visible lightcommunication(VLC) systems for achieving efficient photoelectronic conversion andhigh-fidelity transmission of signals. Antimony sulfide (Sb2S3) as a nontoxic, high optical absorption coefficient,and low-cost semiconductor becomes a promising candidate for applicationsin VLC systems. Particularly, Sb2S3 PDs wereverified to have significantly weak light detection ability in thevisible region. However, the response speed of Sb2S3 PDs with existing device structures is still relatively slow.Herein, through optimizing the device structure for the p-i-ntype PDs, a p-type Sb2Se3 hole transport layer(HTL) is designed to enhance the built-in electric field and to acceleratethe migration of photogenerated carriers for the high responsivityand fast response speed. The optimal thickness of the structure isobtained through the simulation of SCAPS-1D software, and the optimizeddevices show high-performance parameters, including a responsivityof 0.34 A W-1, a specific detectivity (D ( * )) of 2.20 x 10(12) Jones,the -3 dB bandwidth of 440 kHz, high stability, and the valueof the Sb2S3 PDs can reach 60% in the rangeof 360-600 nm, which indicates that the device is very suitablefor working in the visible light band. In addition, the resultingSb(2)S(3) PD is successfully integrated into VLCsystems by designing a matched light detection circuit. The resultssuggest that the Sb2S3 PDs are expected to providean alternative to future VLC system applications.