Preparation, Raman Spectroscopy, Surface Morphology and Optical Properties of TiPcCl2 Nanostructured Films: Thickness Effect

Abstract

Phthalocyanines are of a broad interest in photovoltaic applications. In this study, films of titanium-phthalocyanine-chloride (TiPcCl2) were prepared by the thermal evaporation method. The molecular structure was studied by Raman spectrometer, showing a match between the spectra of the powder and the prepared films. The films' surface was examined by the atomic force microscope, revealing grain size and surface roughness of TiPcCl2 thin films to be 223 and 41 nm, respectively, for a 100 nm thickness. The energy gap was determined to be 1.5 eV, with no observable effect by the thickness change. Additionally, the linear and nonlinear optical constants were calculated from reflectance and transmittance measurements. The values of third nonlinear susceptibility are in order of 10− 12 esu, which is compatible with other phthalocyanines. The nonlinear optical constants indicate that TiPcCl2 films could also be used for optical laser limiters.

Preparation of Hybrid Films Based in Aluminum 8-Hydroxyquinoline as Organic Semiconductor for Photoconductor Applications

“…The dependence of (𝛼ℎ𝜈) on ℎ𝜈 was plotted and Eg opt was evaluated from the x-axis intercept at (αhν) On the other hand, the Urbach energy (E U ) can be used to determine the defects in the band gap and can be determined according to the equation [73,74] α = A a exp hv E U , where, in addition to the parameters defined above, A a is a constant of the material that corresponds to the α at the energy gap. The exponential absorption edge can be interpreted as due to the exponential distribution of local states in the energy band gap [73]. Figure 6d displays the linear relation between ln(α) and hν for the hybrid films.…”

Role of vacuum annealing on the structural, optical properties and Dc conductivity of titanium (IV) phthalocyanine dichloride thin films

“…The thermal activation energy of the electrical conduction impacted by annealing and the presence of oxygen was investigated by Cherian et al [19]. Al-Ghamdi et al investigated how changing film thickness affected the morphology and optical characteristics of TiPcCl 2 [20]. Nevertheless, there is a lack of prior research describing the impact of vacuum heat-treatment conditions affect the performance and phase transition of TiPcCl 2 thin films, it is necessary to characterize the film's phase composition, structure, morphology, and optical characteristics.…”

“…These band energies characterize the lowest values as the optical band gap energy (E g1Opt ) corresponding to the optical absorption Q band for TiPcCl 2 , caused by numerous causes inside the microstructure film, including dislocations and vacancies. The greater band gap energy is known as the fundamental band energy gap (E g2 Opt ) and corresponds to the optical absorption B band for TiPcCl 2 (π to π * )[18,20]. Two bandgap energies are…”