Photoinduced hydrophilic property of zinc oxide thin films prepared by sol-gel dip coating method

ZnO thin films could be fabricated on soda lime glass substrates by sol-gel dip coating method. The thin films fabrication conditions were zinc acetate concentration of 0.10-0.50×103 mol/m3, withdrawal speed of 0.5-1.5×10-3 m/s and calcination temperature of 500°C. The film characteristics (roughness, transparency and photoinduced hydrophilicity) were characterized by atomic force microscopy, UV-vis spectrophotoscopy and contact angle analyzer, respectively. It was found that the decreasing withdrawal speed of the coated film using 0.10×103 mol/m3 zinc precursor could result in a decrease in the film thickness and the film roughness, consequently leading to highly photoinduced hydrophilicity.