Self-Elimination of Intrinsic Defects Improves the Low-Temperature Performance of Perovskite Photovoltaics

Hybrid halide perovskite solar cells have found potential applications beyond terrestrial implementation due to their unique advantages in cold environments. Unfortunately, the pioneer exploits are limited in inferior device efficiency, while the operating mechanisms at low temperatures remain unclear. Here, we revealed substantial performance enhancement for (FA,MA,Cs)Pb(I,Br)₃-based perovskite solar cells at temperatures from 290 to 180 K. Remarkably, the device obtained the highest efficiency of 25.2% (stabilized 24.2%) at 220 K, boosted from a certified efficiency of 23.3% (stabilized 22.8%) at 300 K. We proposed that the phase transition and lattice distortion in perovskite films during temperature cycling effectively activates the self-elimination of intrinsic defects, which contributes to the improved open-circuit voltage (1.153 to 1.229 V) and, thus, efficiency. In addition, the device without encapsulation was tested in the simulated near-space environment, demonstrating their operational feasibility and stability for practical low-temperature applications.