Facile synthesis, characterizations, and impedance spectroscopic features of Zn(II)-bis Schiff base complex films towards photoelectronic applications

Abstract

Complexation of Zn2+ with pyridyl Schiff base (ZnL2) was synthesized. The ZnL2 was examined and characterized using the elemental analysis, NMR, IR, UV-Vis, and mass spectra. ZnL2 was formed within 1:2 molar ratios of metal ion to ligand, respectively, which is proven by continuous variation method. The thin films of ZnL2 are grown on the quartz substrates for optical measurements using thermal evaporation method. The absorbance, transmittance, and reflectance were measured using a spectrophotometric technique, from which many optical parameters were determined. The indirect allowed transition is the most probable transition and the optical energy gap is found to be 2.41 eV. Additionally, the ZnL2 was tested as a photosensitizer material in the thin film form grown onto single crystal of p-Si wafer to form a hybrid organic-inorganic Au/ZnL2/p-Si/Al heterostructure device for the first time. Many electrical aspects were studied for such device including impedance spectroscopic, dielectric constant, electric modulus, and electrical conductivity at various frequencies and under different illumination intensities. The high photosensitivity of Au/ZnL2/p-Si/Al heterojunction for low and high power intensity of light confirmed that the ZnL2 material is a promising candidate photosensitizer for photovoltaic applications.