Optical absorbance and ohmic behavior of PANI and PANI/ZnO nanocomposites for solar cell application

Abstract Polyaniline (PANI) and its nanocomposite with varying concentration of ZnO were synthesized in the laboratory by direct oxidation and In-Situ polymerization methods respectively. These nanocomposites were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), UV–vis absorption and I–V measurement techniques. The XRD results revealed strong and narrow peak corresponding to ZnO (002) plane with a wurtzite crystal structure. FESEM image revealed that the crystalline ZnO was embedded into the PANI matrix and confirmed the formation of PANI/ZnO composite. The elemental composition was analyzed using energy dispersive X-ray analysis (EDX) confirming the presence of ZnO in its nanocomposite. Various chemical bonds and stretching vibrations, assigned to different peaks, were evaluated using Fourier transform infrared (FTIR) spectroscopy. A remarkable optical enhancement was achieved by observing the decrease in band gap with increase in PANI/ZnO composition. The I–V characterization was used to study the influence of nanocomposite on electrical properties of PANI. The conductive property of nanocomposite thin films was found to be increased with increase in PANI/ZnO nanocomposite concentration.