New Chinese tandem solar cell hits 29.71% efficiency with sulfur-based innovation

Researchers at the Chinese Academy of Sciences built a four-terminal perovskite/CIGS tandem solar cell with 29.71% power conversion efficiency.

They used the sulfur-containing additive bis(2-pyridylmethyl) sulfide (2PyS) to reduce defects and slow crystal growth.

The additive also suppressed ion migration and phase instability in the perovskite layer, improving durability.

The device retained more than 91% of its performance after 2,000 hours, strengthening the case for commercial perovskite solar panels.