Paper-based MoS₂/Bi₂S₃ heterojunction photodetectors for broadband detection and fast response

Flexible photodetectors are receiving increasing attention due to their promising applications in wearable optoelectronic devices, bendable imaging sensors, and implantable optoelectronic devices. In this work, a novel strategy for constructing flexible photodetectors based on a hybrid heterojunction of Bi2S3 and MoS2 was proposed. The devices are fabricated on a biodegradable paper substrate using a simple hydrothermal process and vacuum filtration techniques and exhibit a broadband photoresponse from ultraviolet to near-infrared (NIR). Especially, the specific detectivity (D*) of the MoS2/Bi2S3 photodetectors is 3.25 x 10(10) Jones under 365 nm, and the rise/decay time is 0.053 s/0.119 s in the NIR region. In addition, the performance of Bi2S3/MoS2 photodetectors realizes a maximum responsivity (R) of 27.45 mA/W and a fast response time (similar to 0.470 s). These devices exhibit a stable photoresponse under repeated bending. Inexpensive materials and easy fabrication techniques provide a viable strategy for the design and performance optimization of flexible bimetallic sulfide photodetectors.