LAUSR

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 (TaSe2) are still negligible. In view of this, the TaSe2 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 TaSe2 NCs. The flexible self‐powered photoelectrochemical (PEC) type photodetector based on TaSe2 NCs achieves the highest photocurrent density (Pph) of 20.8 µA cm−2 and photoresponsivity (Rph) of 0.208 mA W−1 in 0.5 m KOH. TaSe2 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 Pph of 15.8 µA cm−2 after 95 bending cycles of 120° angle, displaying the great flexibility of TaSe2 NCs. This work demonstrates the potential of TaSe2 NCs for their extended application in PEC‐type devices and flexible electronics.