In this study, we report the synthesis and characterization of CdSe nanocrystals (NCs) by facile hot injection (HI) method. The formation of CdSe NCs was confirmed by X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The optical properties were analyzed by UV-visible and photoluminescence (PL) spectroscopy shows an excitonic peak at 617 nm in PL spectra corresponds to the band gap of ~ 2 eV favourable for optoelectronic device applications. The Photoelectrochemical (PEC) performance of CdSe thin film prepared by spin coating method demonstrates a rise of photocurrent density (Jsc = 0.081 µAcm-2) after illumination. The Mott-Schottky (MS) and electrochemical impedance spectroscopy (EIS) measurements were further carried out to understand intrinsic properties namely the type of conductivity, flat band potential, charge carrier density (ND), charge transfer resistance, and recombination lifetime. The n-type conductivity, the charge carrier density of ND = 1.292 x 1016 cm-3, and recombination lifetime of 32.4 µs suggest the ideal behaviour of CdSe NCs for device quality photoelectrodes.