Perovskite Solar Cells with Hole-Selective Bilayer and Free-Standing Carbon Electrode

Perovskite solar cells are emerging as promising candidates for next-generation solar cells and are being extensively researched due to their rapidly increasing power conversion efficiency. However, high-efficiency perovskite solar cells typically use expensive metals such as gold and silver as electrodes, which undermines their cost advantage and limits their applicability due to the complexity of the deposition processes. To address these challenges, researchers have attempted to use carbon film electrodes; however, their performance generally falls short compared to metal counterparts. In this study, we incorporated a self-assembled hole-selective bilayer into a conventional n-i-p perovskite solar cell with a free-standing carbon electrode, enhancing interfacial contact and promoting efficient hole extraction to the carbon electrode. The resulting device exhibited a higher power conversion efficiency of 24.25%, enhanced stability, and improved reproducibility compared to the control device.