Fabrication of a wearable and foldable photodetector based on a WSe 2 -MXene 2D-2D heterostructure using a scalable handprint technique.

Several studies on semiconductor material-based single-band, high-performance photosensitive, and chemically stable photodetectors are available; however, the lack of broad spectral response, device flexibility, and biodegradability prevents them from being used in wearable and flexible electronics. Apart from that, the selection of the device fabrication technique is a very crucial factor nowadays in terms of equipment utilization and environmental friendliness. This report presents a study demonstrating a straightforward solvent- and equipment-free handprint technique for the fabrication of WSe2 -Ti3 C2 T X flexible, biodegradable, robust, and broadband (Vis-NIR) photodetectors. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), UV-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS) confirm the formation of a WSe2 -Ti3 C2 T X film. The WSe2 -Ti3 C2 T X van der Waals heterostructure plays a key role in enhancing the optoelectrical properties. The as-prepared photodetector exhibits efficient broadband response with a photoresponsivity and a detectivity of 0.3 mA W-1 and 6.8 × 1010 Jones, respectively, under NIR (780 nm) irradiation (1.0 V bias). Under various pressure and temperature conditions, the device's flexibility and durability were tested. The biodegradable photodetector prepared through the solvent- and equipment-free handprint technique has the potential to attract significant interest in wearable and flexible electronics in the future.