Efficient Perovskite Solar Cell Modules with High Stability Enabled by Iodide Diffusion Barriers

Operational stability of efficient opto-electronic conversion is crucial for the success in large-scale application of perovskites devices. Owing to the intrinsically weak structure of perovskites, iodide represents the most volatile constituents, and its diffusion can induce irreversible degradation that continues to present a great challenge to realize stable perovskite devices. Here, we introduce a low-temperature processing strategy to increase the operational stability of high-efficiency perovskite solar modules by engineering low-dimensional diffusion barriers, reducing the unwanted interfacial diffusion of ions by 103–107 times in magnitude. We finally achieved stable and efficient perovskite solar modules with an area of 36 cm2 retaining over 95% of their initial efficiency of over 15% after 1,000 h of heating at 85°C, and 91% after light soaking in AM 1.5 G solar light for 1,000 h, respectively. Our findings provide an effective strategy to realize operationally stable and efficient perovskite solar cell modules.