Dual Role of Cu‐Chalcogenide as Hole‐Transporting Layer and Interface Passivator for p–i–n Architecture Perovskite Solar Cell

Inorganic hole-transport layers (HTLs) are widely investigated in perovskite solar cells (PSCs) due to their superior stability compared the organic HTLs. However, p–i–n architecture when these inorganic HTLs deposited before perovskite, it forms a suboptimal interface quality for crystallization of which reduces device stability, causes recombination, and limits power conversion efficiency device. The incorporation an appropriate functional group such as sulfur-terminated surface on HTL can enhance its interaction with during process. In this work, bifunctional Al-doped CuS film is wet-deposited PSC, besides acting also improves at interface. Urbach energy light intensity versus open-circuit voltage characterization suggest formation better-quality sulfide HTL–perovskite heterojunction. degradation behavior sulfide-HTL-based devices studied, where be observed that after 2 weeks storage controlled environment, retain close 95% initial efficiency.