Impact of transparent conducting substrates on structural and optical of Titanium(IV) phthalocyanine dichloride (TiPcCl₂) thin films

This study investigates the impact of transparent conducting substrates, specifically indium-doped tin oxide (ITO) and fluorine-doped tin oxide (FTO), on the structural and optical characteristics of thermally evaporated Titanium phthalocyanine chloride (TiPcCl₂) thin films. The crystalline structure of TiPcCl₂/quartz thin films was verified by X-ray powder diffraction (XRD) patterns while amorphous phases were detected in TiPcCl₂/ITO and TiPcCl₂/FTO thin films. Field emission scanning electron microscopy (FESEM) images provided evidence that the morphology of TiPcCl₂ thin films may be affected by a lattice mismatch between TiPcCl₂ and substrates. Fourier-transform infrared spectroscopy (FT-IR) also showed that the substrates did not change the molecular structure of TiPcCl₂. UV–Vis-NIR spectroscopy demonstrated that the substrates had a significant influence on the optical gap, optical constants, dielectric constant dielectric loss functions and optical conductivity of TiPcCl₂ thin films. Lastly, the nonlinear susceptibility χ⁽³⁾, the nonlinear refractive index \({{\varvec{n}}}_{2}\) ${\mathit{n}}_2$ and the nonlinear absorption coefficient β_(c) for TiPcCl₂/ITO, TiPcCl₂/FTO, and TiPcCl₂/quartz were obtained using a semi-empirical approach. The changes seen in optical properties could be due to changes in the crystal structure and morphology, which are closely connected to the properties of the substrate material. Overall, the results for TiPcCl₂ thin films are promising, and they are appropriate for novel optoelectronic device applications.