Thin films of chlorosubstituted vanadyl phthalocyanine: charge transport properties and optical spectroscopy study of structure

Electrophysics and structure of thin films of chlorosubstituted vanadyl phthalocyanine (VOPcCl₁₆) were studied using complementary experimental and theoretical techniques. To study charge transport properties of the latter films, organic field-effect transistors were fabricated by physical vapor deposition. The device exhibited good air stability without any extent of degradation after a storage in air for two months. The charge carrier mobility was measured to be (2.0 ± 0.1) × 10⁻³ cm² V⁻¹ s⁻¹. This value was rationalized by poor ordering of the VOPcCl₁₆ films revealed with the use of polarization dependent Raman and UV–Vis spectroscopies as well as by X-ray diffraction. Apart from this, we performed a detailed assignment of all intense bands in the vibrational spectra of VOPcCl₁₆. To this end, the experimental IR and Raman data were complemented by quantum chemical calculations at the B3LYP/6-311++G(2df,p) level of theory.