Investigating the role of film thickness on the physical properties of sol-gel coated CuO thin films: Discussing its potentiality in optoelectronic applications

•CuO TFs having different thicknesses prepared by sol–gel dip coating method.•XRD with Raman FT-IR profiles revealed the monoclinic symmetry of CuO TFs.•High absorption in visible region made it a suitable material as photocatalyst.•Surface-dependent electrical properties are evaluated by surface resistance mapping.•CuO TFs shows excellent photocatalytic efficiency for MO dye in water. In the present study, Cupric oxide thin films with varying thicknesses were successfully fabricated on a glass substrate at room temperature via dip coating technique. Highly crystalline CuO films with monoclinic symmetry were examined from XRD which was further confirmed with the help of Raman spectra. FESEM results showed a uniform coating surface with nano-sized grains without any agglomerations. The elemental composition of Cu and O atoms is in a 1:1 stoichiometric ratio for samples having higher thickness values. Strong absorption in the visible and nearby IR region makes the sample a viable choice in the field of photovoltaics. The estimated band gap values from the Tauc plot ranges from 1.10 eV to 1.26 eV. All the samples exhibited a p-type nature and their uniformity of resistance over the film surface was examined by resistance mapping. Hall measurements indicated the direct proportionality of sample resistivity with thickness.