Thin films of molecular materials synthesized from C32H20N10M (M = Co, Pb, Fe): Film formation, electrical and optical properties

In this work, the synthesis of molecular materials formed from metallic phthalocyanines and 1,4-phenylenediamine is reported. The powder and thin film (∼80-115 nm thickness) samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds in the IR spectroscopy studies, which suggests that the thermal evaporation process does not alter these bonds. The morphology of the deposited films was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and their optical and electrical properties were studied as well. The optical parameters have been investigated using spectrophotometric measurements of transmittance in the wavelength range 200-1200 nm. The absorption spectra recorded in the UV-vis region for the deposited samples showed two bands, namely the Q and Soret bands. The optical activation energy was calculated and found to be 3.41 eV for the material with cobalt, 3.34 eV for the material including lead and 3.5 eV for the material with iron. The effect of temperature on conductivity was measured for the thin films and the corresponding conduction processes are discussed in this work.