Two-Dimensional SnSe Films on Paper Substrates for Flexible Broadband Photodetectors

Paper-based devices have aroused researchers' enormous interest due to the increasing need for disposable flexible optoelectronic devices. Here, we used a straightforward painting method to integrate semiconducting materials on an A4 paper substrate to create high-performance photodetectors. A solvent-free 2D SnSe film painted on paper allowed electrons to separate from holes more effectively, thereby reducing the level of recombination between holes and electrons. The paper-based SnSe photodetectors that we prepared demonstrated a robust, sensitive response over a wide range of spectral ranges from ultraviolet (254 nm) to near-infrared (1550 nm). The devices were characterized by fast response times (rise time of 0.066 s and fall time of 0.066 s). A high-performance photodetector was achieved by combining a photoconductive and pyroelectric effect. Additionally, we constructed the carbon nanotube (CNTs) films as electrodes in order to form an ohmic contact between the carbon nanotubes and the semiconductor, and the photogenerated electrons were able to efficiently move through the carbon nanotubes. Our research could contribute to the development of flexible photodetection devices that are low-cost, eco-friendly, and disposable.