Iodine Doping Implementation Effect on the Electrical Response in Metallophthalocyanines (M = Cu, Co, Zn), for Electronic and Photovoltaic Applications

We report the structural organization and its effect on the current response of the conducting domains in MPcs (M = Cu, Co, Zn) films, deposited by vacuum thermal evaporation and doped by the presence of iodine vapors. Structural and surface features of the doped metallophthalocyanines (MPcs) were studied by using IR spectroscopy, X-ray diffraction, atomic force microscope (AFM) and scanning electron microscope (SEM). DFT calculations were carried to study the interaction between iodine and MPcs molecules and establish the influence of iodine on the electronic behavior of these species and the changes on the frontier molecular orbitals. This interaction is thermodynamically favored, and the mechanism of electronic transit involving the iodine atoms providing electrons to the transfer. The I-MPc films have a mainly amorphous structure, some crystallinity in the MPcs α and β forms. A roughness between 18.41 and 99.02 nm and particle size between 1.35 and 15 μm. By evaluating the electrical behavior of the flexible PET/ITO/I-MPc/Ag devices, it was found that J-V curves under illuminated conditions show an increase of curves values upon the I-MPc, indicating that the flexible films are photosensible. J_sc between 1.59 × 10⁻⁵ and 2.41 × 10⁻⁷ A/cm², conductivities between 6.17 × 10⁻⁸–2.54 × 10⁻⁷ Scm⁻¹ and photosensibility values of up to 133%.