China team breaks 30% efficiency barrier in perovskite solar cells

A joint research team in China has developed a new method that, for the first time, has allowed a key type of advanced perovskite solar cell to exceed the 30 percent efficiency mark.

The groundbreaking research, led by Tan Hairen, a professor at Nanjing University, and Chang Chao, a professor at the National Sciences Institute of Innovation, was published on the Nature website on Tuesday.

The efficiency of perovskite cells has been hard to improve, mainly because it was difficult to accurately track and control electric charges or carriers without damaging the cells, according to Tan.

To overcome the bottleneck, researchers led by Chang used a non-destructive terahertz detection method, acting like a precise scanner that enables scientists to observe charge movement in real time without disrupting the cell's operation.

Using this method, the team found that a significant amount of energy was being lost at a critical interface inside the cell.

In response, Tan led the development of a special "dipolar passivation" layer that, functioning like an urban one-way street, efficiently guides charges and prevents waste.

The terahertz analysis confirmed that the strategy effectively reduced energy loss, increasing charge mobility by over 68 percent and enabling charges to travel much farther.

A third-party evaluation revealed that the new solar cell achieved a certified efficiency of 30.1 percent, marking the first time this type of cell has surpassed the 30 percent barrier, said Lin Renxing, an assistant professor at Nanjing University and the first author of the article.

"The research provides a clear and practical new strategy for designing more efficient and affordable solar cells in the future," Lin added.