Flexible Self‐Powered Electrochemical Photodetector Functionalized by Multilayered Tantalum Diselenide Nanocrystals

Abstract Few layered transition metal dichalcogenides (TMDCs) are widely used in electrochemical systems due to their unique optical and electronic properties including applications over a large area. Despite the widespread use of 2D layered materials as active components of photoanode, electrochemical conversion studies of few‐layered Tantalum diselenide (TaSe 2 ) are still negligible. In view of this, the TaSe 2 nanocrystals (NCs) are successfully synthesized by using the facile liquid‐phase exfoliation (LPE) approach. Different physiochemical characterization confirms the inherent physical and optical properties of TaSe 2 NCs. The flexible self‐powered photoelectrochemical (PEC) type photodetector based on TaSe 2 NCs achieves the highest photocurrent density ( P ph ) of 20.8 µA cm −2 and photoresponsivity ( R ph ) of 0.208 mA W −1 in 0.5 m KOH. TaSe 2 NCs demonstrate the excellent self‐driven ability and also unveil decent response under applied bias potential in different concentration of KOH electrolyte. Moreover, the electrode shows excellent ON/OFF switching stability up to 1000 s even after the 1 month of storage in the air. Importantly, the photodetector retains the P ph of 15.8 µA cm −2 after 95 bending cycles of 120° angle, displaying the great flexibility of TaSe 2 NCs. This work demonstrates the potential of TaSe 2 NCs for their extended application in PEC‐type devices and flexible electronics.