Effects of polyaniline thickness on photovoltaic properties of PANI/tio2 photovoltaic cells

Abstract

Polyaniline (PANI)�is a cheap conducting polymer that exhibits�p-type properties with high conductivity and unique redox properties. In this work, PANI was synthesized directly on TiO2/FTO substrates by electropolymerisation from acidic aqueous solutions of aniline to form PANI/TiO2 p-n junctions with photovoltaic properties.�The thickness of the PANI layer was varied by varying electrodeposition time: 15, 30, and 45 min at the same current density of 2 mA cm-2.�The thicknesses of the deposited PANI layers were examined with Scanning Electron Microscope (SEM). Short-circuit currents (ISC) and open-circuit voltages (VOC) of fabricated Pt/PANI/TiO2/FTO cells are investigated.�It was found that the PANI electrodeposition time at least 30 min corresponding to a PANI thickness of�399 nm was required for the cell to exhibit significant photovoltaic properties. Furthermore, the TiO2�nanorods that is a remarkable morphology of the n-type TiO2�was synthesized by electrochemical anodization of titanium in a fluoride-based electrolyte with�varying�anodization times: 45 and 60 min at the constant potential of 60 V. It was found that the anodization time at 60 min�is the sufficient condition for the PANI electrodeposition at 45 min to exhibit photovoltaic properties.