Structural and electrical property studies on polypyrrole based organic–inorganic nanocomposites for photodiode related applications

• Pyrrole monomers were electropolymerized on the composite working electrodes through controlling the flow of charge values in them.
• The conductivity type and flat band potential of the composite electrodes were studied using Mott–Schottky plots.
• Electron transfer kinetics has been explained theoretically using a band diagram.

Employing electropolymerization route, a coulombic-controlled approach was adopted to polymerize the pyrrole monomers on the TiO2:SnO2 made nanocomposite working electrodes. The absorbance values of the composite electrodes in the UV region were found to improve the rate of formation of oligomeric products from the pyrrole monomers. The role of anionic dopant in the evolution of polymer structures has been discussed using bi-polaronic states. The polymer deposits were studied using FT-IR spectroscopy to elucidate their functional groups and their three-dimensional morphological arrangements were perceived using atomic force microscopy and scanning electron microscopy. A negative shift in the flat band potential was observed from the Mott–Schottky plots, as a function of Sn composition in the composite electrodes, which favours a faster rate of electron transfer, while the Sn sites minimizes the rate of electron–hole recombination.