The effect of Zn metallophthalocyanine on the optical and structural properties of sol-gel spin coated TiO₂ thin films

In this study, TiO2, TiO2/ZnPc and ZnPc thin films were deposited on glass substrates by spin coating method and the effect of ZnPc doping concentration on the optical and structural properties of the films was investigated. A spectrophotometer in the 300-1100 nm wavelength range was used to measure the optical transmittance of thin films. UV-Vis studies showed that transmittance of the films decreased with the increasing concentration of ZnPc in the ranges corresponding to the B and Q band absorption regions, which are the characteristic peaks of phthalocyanines between 300-400 nm and 600-700 nm, respectively. Scanning electron microscopy (SEM) was used to characterize the surface morphology of thin films and they were observed to be homogeneously coated. X-ray measurements of annealed films showed an anatase-brookite mixed phase and it was found that crystal size decreased with increasing ZnPc concentration.