The optical properties of polypyrrole(Ppy) thin films upon 2 MeV electron beam irradiation changes with different doses. The induced changes in the optical properties for Ppy thin films were studied in the visible range 300 to 800 nm at room temperature. The optical band gap of the pristine Ppy was found to be 2.19 eV and it decreases up to 1.97 eV for a 50 kGy dose of 2 MeV electron beam. The refractive index dispersion of the samples obeys the single oscillator model. The obtained results suggest that electron beam irradiation changes the optical parameters of Ppy thin films.

An easy and cost-effective route is demonstrated to grow spongy-network-like polyaniline (SpN-PANI) thin films on stainless steel (SS) by galvanostatic electrodeposition. Through X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) characterizations, the physicochemical properties of the SpN-PANI thin films were fine-tuned for supercapacitor application. The hydrophilic nature of SpN-PANI thin films was examined by using contact angle measurements. Next, the capacitive behavior of the SpN-PANI thin film was assessed by using cyclic voltammetry (CV), galvanostatic charging-discharging (GCD), and electrochemical impedance spectroscopy (EIS). Specifically, these results show that SpN-PANI thin films can exhibit a maximum specific capacitance of 580 F.g⁻¹ at a scan rate of 5 mV.s⁻¹ in a 0.5 M Na₂SO₄ electrolyte solution, as well as superior cycling stability (84% capacity retention after 1000 cycles). Thus, the strategy presented here can be applicable to produce a SpN-PANI-based thin film which has prospects as an active electrode material for supercapacitor devices.

Polypyrrole (PPy) thin films were deposited on stainless steel and ITO coated glass substrate at a constant deposition potential of 0.8 V versus saturated calomel electrode (SCE) by using the electrochemical polymerization method. The PPy thin films were deposited at room temperature at various monomer concentrations ranging from 0.1 M to 0.3 M pyrrole. The structural and optical properties of the polypyrrole thin films were investigated using an X-ray diffractometer (XRD), FTIR spectroscopy, scanning electron microscopy (SEM), and ultraviolet—visible (UV—vis) spectroscopy. The XRD results show that polypyrrole thin films have a semi crystalline structure. Higher monomer concentration results in a slight increase of crystallinity. The polypyrrole thin films deposited at higher monomer concentration exhibit high visible absorbance. The refractive indexes of the polypyrrole thin films are found to be in the range of 1 to 1.3 and vary with monomer concentration as well as wavelength. The extinction coefficient decreases slightly with monomer concentration. The electrochemically synthesized polypyrrole thin film shows optical band gap energy of 2.14 eV.