Effect of substrate types on the structural and optical properties of nickel (II) tetrasulfonated phthalocyanine thin films

Chemical spray pyrolysis (CSP) technique has been employed to deposit tetrasulfonated nickel phthalocyanine (NiTsPc) thin films on different substrate types. Since substrate type is one of the important parameters in CSP, NiTsPc thin films were deposited on different substrate types in order to investigate their structural and optical properties by using different techniques. The structural properties were investigated by X-ray diffraction (XRD) and atomic force microscope (AFM), the optical properties were investigated by ultraviolet visible (UV-Vis) spectrophotometer and fluorescence spectrophotometer. From XRD results, it was shown that the highest crystallinity of the thin films was when using polymer as substrate. The observed topographical images from showed that the roughest surface was when using micro glass as substrate. The absorption spectra recorded in the wavelength range 190-1100 nm revealed two absorption bands, namely, the Soret and the Q-band and that the highest absorption intensity was when using glass as substrate. In addition, UV-Vis spectra showed that thin films deposited on different substrate types have direct energy gap. The energy gap for the NiTsPc thin films were calculated from Tauc equation and compared with results obtained from fluorescence measurements. The highest energy gap was observed for NiTsPc thin films deposited on glass substrates with . It was observed that preparation conditions affect the properties of the thin films and that the different substrates have high impact on the structural and optical properties of the deposited NiTsPc thin films. The crystallinity, grain size, roughness and the optical constants were strongly affected by the different substrates.