High-performance low-power Photoelectrochemical photodetector functionalized by titanium Diselenide thin film

Abstract

Titanium Diselenide (TiSe2) thin films have become attractive options for high-performance optoelectronic devices due to their exceptional optical and electronic properties and distinctive layered structure. However, despite their promise, TiSe2 has not been well explored for Photoelectrochemical photodetector applications, especially when it comes to improving its carrier dynamics, stability, and spectrum response under operating circumstances. Present article demonstrates significant advancement in the field by utilization of large area TiSe2 thin film for fabrication of high-performance photoelectrochemical photodetector (PEC-PD). Herein, TiSe2 crystalline powder is grown using direct vapour transport technique followed by elemental and morphological confirmation via Energy Dispersive X-ray Analysis and Field Emission Scanning Electron Microscopy that revealed layered hexagonal structure along with maintaining stoichiometry. From the grown compound of TiSe2, thin films are deposited by physical vapour deposition and well characterised. Powder X-Ray Diffraction analysis confirmed hexagonal structures whereas Raman spectroscopy identified the vibrational modes of TiSe2 in thin film. Atomic Force Microscopy portrayed surface smoothness along with uniformity. This large area TiSe2 thin film is utilised as working electrode in the application of PEC-PD that demonstrated optimum performance by achieving high detectivity of about 7.36 ± 0.02 × 108 Jones under low-power operation of 100 mV bias. The device indicated rapid photoresponse dynamics by exhibiting a rise and decay time of 12 ms and 33 ms respectively. To the best of our knowledge, this is the first report of a TiSe2 thin-film-based PEC-PD. Outcome of current study showcases the potential of TiSe2 in facilitating fabrication of high-performance optoelectronic devices.