Fabrication of Planar Perovskite Solar Cells Using Ternary Metal Oxide Nanocomposite as Hole-Transporting Material

This work uses a hole-transporting copper cobaltite/copper oxide nanocomposite to fabricate carbon-based MAPbI3 PSCs. The copper cobaltite/copper oxide HTM-based PSC results show the highest power conversion efficiency (PCE = 7.32%) compared with an HTM-free device. The highest photocurrent density (Jsc = 15.17 mA/cm2), open-circuit voltage (Voc = 0.82 V), and fill factor (FF = 0.59) are achieved for the PSC fabricated with hydrothermally synthesized copper cobaltite/copper oxide nanocomposites. Electrochemical impedance spectroscopy is used to analyze the charge transfer resistance (Rs) and the capacitive behavior of copper cobaltite/copper oxide nanocomposite. The maximum electron lifetime of 35.16 μs is witnessed for the PSCs fabricated with 3 mg mL−1 of copper cobaltite/copper oxide (H1). The efficiency of the copper cobaltite/copper oxide-based PSC remains unchanged, showing no further perovskite layer degradation.