Molecular press annealing enables robust perovskite solar cells
- Jianfei Hu
- Qingbin Cai
- Yuexin Lin
- Yuanhui Xiao
- Li Yang
- Kun Wei
- Cuiping Zhang
- Xiaofeng Li
- Zhihan Liao
- Qingming Huang
- Yuanyuan Li
- Ye Yang
- Chao Liang
- Jinbao Zhang
2026-01-08
Thermal annealing improves the crystallinity of perovskite films and boosts their power conversion efficiencies (PCEs) in solar cells but also induces surface iodine loss and local lattice degradation. We demonstrate a molecular press annealing (MPA) strategy in which a 2-pyridylethylamine film is thermally and pressure-bonded to the perovskite surface. Real-time healing of iodine vacancies occurred during annealing and the lead-iodine framework was stabilized through optimized ligand engineering, resulting in enhanced structural integrity and long-term stability of perovskite films. This strategy enabled n-i-p perovskite solar cells to achieve a PCE of 26.6% (certified 26.5%). Notably, the devices retain 98.6 and 97.2% of their initial PCEs after 1617 hours of continuous operation under maximum power point tracking [ISOS-L-3 protocol, 85°C, 60% relative humidity (RH)] and 5280 hours of ambient storage (ISOS-D-1 protocol, room temperature, 10% RH).