Strategy for Improving Stability and Power Conversion Efficiency in Perovskite Solar Cells: Interlayer and Electrode

Perovskite solar cells (PSCs) have emerged as promising photovoltaic technologies due to their rapid increase in power conversion efficiency (PCE), now exceeding 26%. However, their long-term operational instability, especially under thermal, moisture, and illumination stress, remains a major barrier to commercialization. This review summarizes recent advances in interface and electrode engineering strategies aimed at simultaneously improving the stability and efficiency of PSCs. In particular, charge transport layer optimization is emphasized, including the use of dopant-free polymers, bilayer structures, and inorganic materials, as well as interfacial passivation approaches. Furthermore, emerging electrode technologies, such as carbon-based electrodes and hybrid metal–carbon architectures, which address issues of metal ion migration, corrosion, and interfacial degradation, are explored. Interfacial modifiers, molecular passivators, and dimensional control strategies are also reviewed for their role in enhancing charge extraction and suppressing recombination. Through a comprehensive discussion of these materials and device-level innovations, insight is provided into scalable pathways for fabricating stable and high-performance PSCs suitable for real-world applications.