'Semi-stable' state identified, boosts solar material's performance

Researchers at Chalmers University of Technology in Sweden have identified a previously unknown low-temperature phase of formamidinium lead iodide, a key halide perovskite material known for its excellent optoelectronic properties but limited by instability. Using advanced computer simulations enhanced by machine learning, the team revealed that as the material cools, its molecules enter a semi-stable state. This discovery fills a critical gap in understanding the material’s structure and behavior, which is essential for engineering and optimizing halide perovskite-based solar cells and LEDs. The study highlights the challenges of modeling halide perovskites due to their complex nature, requiring powerful supercomputers and extended simulation times. By integrating machine learning, the researchers achieved simulations thousands of times longer and on a much larger atomic scale than before, bringing models closer to real-world conditions. Experimental validation was conducted in collaboration with the University of Birmingham, confirming the simulation results at temperatures as low as -200°C. These insights are expected