New Chiral Switch with Low Energy Barrier: Perovskite Solar Cell Efficiency Exceeds 26%, Lifespan Surpasses 2000 Hours
On January 20, 2026, a significant advancement in perovskite solar cells was reported, highlighting the potential of molecular selective contact layers to enhance photoelectric conversion efficiency. Traditional rigid hole-selective contact layers, while promoting charge carrier transport through ordered π–π stacking, often face challenges due to strong intermolecular interactions that can lead to molecular aggregation, negatively impacting interface uniformity and stability.
A research team from Zhengzhou University, including Li Meng, Wu Youxin, Yang Shengchun, and Liang Chao from Xi’an Jiaotong University, introduced a novel molecular contact material based on an axially chiral framework (PPBCz-4). This material achieves an extremely low isomerization barrier of 4.37 kcal mol⁻¹ through the non-planar arrangement of two π systems and restricted N–C rotation. Such structural design effectively suppresses aggregation and promotes uniform stacking, resulting in a stable interface.
Devices utilizing this material demonstrated photoelectric conversion efficiencies of 26.91% (with a certified efficiency of 26.44%) in small areas (0.08 cm²) and 22.14% in large area modules (69 cm²). Notably, these devices exhibited a T₉₀ lifespan exceeding 2000 hours under continuous maximum power point operation at 65°C.
Key Highlights:
- Innovative Axial Chirality Design: The configuration of non-planar π systems and restricted N–C bond rotation facilitates a low isomerization barrier of 4.37 kcal mol⁻¹, combining dynamic configurational adaptability with high-order stacking capability.
- High Efficiency and Stability: As a hole-selective layer, PPBCz-4 enables devices to achieve a certified efficiency of 26.91% in small areas, along with a T₉₀ lifespan surpassing 2000 hours under continuous illumination at 65°C, showcasing excellent resistance to thermal and light degradation.
- Large Area Modular Application Potential: The 69 cm² module achieved an efficiency of 22.14%, demonstrating remarkable scalability and process compatibility, laying a solid foundation for industrial advancement.
For further details, refer to the study: Yang, W., Guan, X., Cai, Q. et al. “Axially chiral molecular contacts with low isomerization barriers for perovskite solar cells.” Nat. Photon. (2026). https://doi.org/10.1038/s41566-025-01817-8
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Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/chiral-switch-with-low-energy-barrier-boosts-perovskite-solar-cell-efficiency-over-26-and-longevity-beyond-2000-hours/
