Synthesis and characterization of ZnO thin film by low cost modified SILAR technique

The ZnO thin film is prepared on Fluorine Tin Oxide (FTO) coated glass substrate by using SILAR deposition technique containing ZnSO₄.7H₂O and NaOH as precursor solution with 150 deeping cycles at 70 °C temperature. Nanocrystalline diamond like ZnO thin film is characterized by different characterization techniques such as X-ray diffraction (XRD), Fourier transform (FT) Raman spectrometer, Field Emission Scanning Electron Microscopy (FE-SEM) with Energy dispersive X-Ray Analysis (EDAX), optical absorption, surface wettability and photoelectrochemical cell performance measurement. The X-ray diffraction analysis shows that the ZnO thin film is polycrystalline in nature having hexagonal crystal structure. The FT-Raman scattering exhibits a sharp and strong mode at 383 cm⁻¹which confirms hexagonal ZnO nanostructure. The surface morphology study reveals that deposited ZnO film consists of nanocrystalline diamond like morphology all over the substrate. The synthesized thin film exhibited absorption wavelength around 309 nm. Optical study predicted the direct band gap and band gap energy of this film is found to be 3.66 eV. The photoelectrochemical cell (PEC) parameter measurement study shows that ZnO sample confirmed the highest values of, short circuit current (I_sc - 629 mAcm⁻²), open circuit voltage (V_oc - 878 mV), fill factor (FF - 0.48), and maximum efficiency (η - 0.89%), respectively