Atomic Layer Deposition for Perovskite Solar Cells: Interface Engineering, Stability Enhancement, and Future Prospects

Perovskite solar cells (PSCs) have achieved rapid progress in recent years owing to their high-power conversion efficiency (PCE), low cost, and processability. However, poor device stability and carrier recombination remain significant obstacles to further development. Atomic layer deposition (ALD), with its atomic-level control over film thickness, excellent uniformity, and interfacial engineering capability, has attracted considerable attention in PSC research. This review summarizes the applications of ALD in PSCs, including low-temperature synthesis (typically below 350 °C), thickness and composition control (approximately 1 nm per 10 ALD cycles), defect passivation, encapsulation (water vapor transmission rates as low as 10−6 g·m−2·day−1 under optimized conditions), and tandem devices. In addition, the mechanisms by which ALD enhances device efficiency and stability are discussed in depth, and the challenges and future prospects of this technique are analyzed.