Optical and electrical performance of ploypyrrol thin films and its hybrid junction applications

In this work, polypyrrole (PPy) thin films were prepared by the in-situ chemical oxidative polymerization technique. The identification of the prepared films was done by using scanning electron microscopy and X-ray diffraction. The optical characterization of PPy films was achieved to obtain the optical band gaps ( = 1.44 and 2.63 eV) and Urbach energy ( = 402 meV). The capacitance and conductance characteristics as a function of frequency at different biasing voltage show the influence of interface under AC conduction. The principle hybrid junction and photovoltaic parameters were extracted from the dark and illuminated current density-voltage characteristics. The PPy-based junction demonstrated adequate rectification behavior. The high value of ideality factor was interpreted to the interface states and the influence of inhomogeneity at the organic/inorganic interface. The results show that the PPy-based hybrid junction could be utilized as an optical sensor for the optoelectronic application.