MoS-on-paper optoelectronics: drawing photodetectors with van der Waals semiconductors beyond graphite

We fabricate paper-supported semiconducting devices by rubbing a layered molybdenum disulfide (MoS 2 ) crystal onto a piece of paper, similar to the action of drawing/writing with a pencil on paper. We show that the abrasion between the MoS 2 crystal and the paper substrate efficiently exfoliates the crystals, breaking the weak van der Waals interlayer bonds and leading to the deposition of a film of interconnected MoS 2 platelets. Employing this simple method, which can be easily extended to other 2D materials, we fabricate MoS 2 -on-paper broadband photodetectors with spectral sensitivity from the ultraviolet (UV) to the near-infrared (NIR) range. We also used these paper-based photodetectors to acquire pictures of objects by mounting the photodetectors in a homebuilt single-pixel camera setup. We open up the possibility of fabricating devices based on van der Waals materials on standard copier paper using a process similar to the action of drawing/writing with a pencil on paper.