Electrical and optical properties of C₄₆H₂₂N₈O₄KM (M{double bond, long}Co, Fe, Pb) molecular-material thin films prepared by the vacuum thermal evaporation technique

In this work, the synthesis of new materials formed from metallic phthalocyanines (Pcs) and double potassium salt from 1,8-dihydroxianthraquinone is reported. The newly synthesized materials were characterized by scanning electron microscope (SEM), atomic force microscopy (AFM), infrared (IR) and Ultraviolet-visible (UV-vis) spectroscopy. The powder and thin-film samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds as in the IR spectroscopy studies, which suggests that the thermal evaporation process does not alter these bonds. The effect of temperature on conductivity and electrical conduction mechanism was measured in the thin films (∼137 nm thickness). They showed a semiconductor-like behaviour with an optical activation energy arising from indirect transitions of 2.15, 2.13 and 3.6 eV for the C₄₆H₂₂N₈O₄KFe, C₄₆H₂₂N₈O₄KPb and C₄₆H₂₂N₈O₄KCo thin films.