Flexible and Hand-Printed Photodetector Based on Mg–SnS Nanoflakes

High-performance photodetection is becoming increasingly important for the advancement of technology. Very few materials are available that can respond to light across the ultraviolet to the infrared (IR) range. These materials are very much required for optoelectronic devices. Two-dimensional (2D) layered materials became relevant following the discovery of graphene. Transition-metal chalcogenides belong to the 2D layered material class, as well. The field of optoelectronic applications makes extensive use of them. The current study investigated the photodetector device by doping pure SnS nanoflakes with Fe, Mn, Mg, Pd, and W. These materials were used to create paper-based, flexible, biodegradable electronics through a solvent-free hand-print technique. The Mg-doped SnS photodetector has the highest photo response performance among the devices. With a specific detectivity value of 1.64 × 10¹⁰ Jones and a responsivity value of 52 mA W^–1, the 7% Mg-doped SnS exhibits the best response among the different Mg doping. Extensive on–off cycles were used to assess the switching stability of the device, observing clear photo response and photoswitching behavior. The photoswitching curves of the device as created and the device after 8 months show an amazing degree of consistency, indicating the device’s resilience in open-air environments. The device was bent repeatedly to test its twisting, foldability, and flexibility. It continuously displayed a definite photoswitching trend. Testing in a very basic and acidic environment verified the device’s chemical stability, and its photo response and photoswitching functions remain functional. When the paper-based photodetector’s thermal stability was examined at various temperatures, the findings demonstrated that the device continues to function normally and produce photocurrent. Considering how quickly technology is developing nowadays and how much waste is produced by electronics, switching to paper-based gadgets could help achieve sustainability goals.