Electrochemical Impedance Spectroscopy of Perovskite and Polymer Films

Electrochemical impedance spectroscopy (EIS) measurements were performed on Zahner Electrochemical Workstation with an active area of 0.2 cm² under the xenon white light source of intensity 400 W m⁻² at different external applied bias of 0, 0.2, 0.4, 0.6, 0.8, 1.0 V applying the ac amplitude of 20 mV in the frequency range of 100 mHz to 1 MHz. The cell set-up consists of modified photoelectrochemical cell (PECC) to hold the liquid electrolyte in two electrode system with perovskite or polymer coated ITO substrates as working electrode and platinum wire as counter electrode. The liquid electrolyte used is 0.1 M solution of tetrabutylammonium perchlorate (TBAClO₄) in dichloromethane (DCM) for perovskite films as working electrode. The perovskite films are stable in this liquid electrolyte^{23 (link),39 (link),78 (link),79 (link)}. For polymer films as working electrode, 0.1 M aqueous solution of KCl was used as liquid electrolyte. The EIS data were analysed using zView software. All the measurements were carried out in the ambient air atmosphere.