Production and characterization of Cu-doped perovskite thin film electrodes for supercapacitors

In this study, perovskite thin-film electrodes were produced by doping different amounts of copper (Cu% = 1, 2, 4, 6, 8) on fluorine tin oxide (FTO) substrates at room temperature by chemical bath deposition (CBD) and dip-coating methods. The structural properties of these thin films were determined by X-ray diffraction (XRD), and their chemical compositions were analyzed by EDX (Energy Dispersive X-ray). Surface morphologies were imaged with FESEM. Time-dependent current–voltage (I-V) measurements were taken with a Keithley 2400 SourceMeter. The specific capacitance of each sample was measured at room temperature, in the dark at scanning rates of 10, 25, and 50 mV/s in the range of −0.5 to 0.7 V. The maximum specific capacitance was observed on 2% Cu-doped perovskite thin film (761 F/g) at the lowest scanning speed (10 mV/s). Regarding EDX analysis, 0.44–3.20–1.23–1.83–0.98% Cu atoms were detected on the surface of 1–2–4–6–8% Cu-doped structures. The higher precipitation in the structure will cause a resistance between the bands and thus decrease the load storage capacity.