Thermal annealing effects on optical and dielectric properties of TiOPc thin films for optoelectronic and photonic applications

Abstract Titanyl phthalocyanine (TiOPc) is a metal phthalocyanine compound with interesting electronic and catalytic properties, making it useful in various applications. TiOPc films were fabricated using the conventional thermal technique, and their optical and structural characteristics were examined before and after annealing. The FTIR spectra demonstrate a correspondence in the peak positions of the films pre- and post-annealing. Additionally, the spectra of the annealed sample show a decrease in C=O and the formation of a coordination bond between the Ti dopant and the phthalocyanine molecule. X-ray diffraction has been employed to analyze the structural properties of TiOPc films, which show an amorphous behavior before and after annealing. The AFM images show the presence of peaks and valleys of varied sizes. This leads to enhanced light trapping and scattering, improving light absorption and optical properties of the film. The energy gap of TiOPc decreased by about 7 % after annealing, which indicates the thermal stability of these films. The dielectric constant, ε1, and the dielectric loss, ε2, show variation with the annealing. This comprehensive analysis will provide valuable insights into the structural and optical characteristics of the TiOPc thin film, paving the way for innovative advancements in materials science and device technologies.