Development of Composite Semiconductor Films Based on Organotin Complexes Doped with Cobalt Porphine for Applications in Organic Diodes

In this work, we present the green synthesis of complex <b>A</b>-<b>E</b> derived from β-hidroxymethylidene indanones by ultrasound, which allowed for the obtaining of compounds in a shorter time and with good yields. These organotin complexes were then doped with cobalt porphine and incorporated into a poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) matrix to manufacture composite semiconductor films. The semiconductor films were characterized through atomic force microscopy, examining their topography, Knoop hardness (around 17 HK), and tensile strength, which varied from 5 × 10^-4 to 7 × 10^-2 Pa. The optical behavior was evaluated, revealing that the changes in these characteristics are related to the type of organotin complex present in the composite film: the transmittance ranged from 77% to 86%, while the reflectance varied from 13% to 17%. The band gap, calculated using the Kubelka-Munk function F(KM), was approximately 3.7 ± 0.19 eV for all the semiconductor films. Finally, we assessed the electrical behavior of the composite films through current-voltage (I-V) measurements under different lighting conditions. The I-V curves demonstrated that they share a saturation current density of 3.46 mA/mm². However, they differ in their conduction rates within the ohmic regimen. These composite films' optical and electrical properties suggest their potential use in developing electronic devices like organic diodes.