First bendable perovskite solar cell to hit record 22.8% efficiency – Interesting Engineering

A flexible solar cell breakthrough

Perovskite solar cells offer great advantages for developing low-cost, high-efficiency solar panels. To date, scientists have achieved efficiencies as high as 33.9 percent with rigid perovskite/silicon tandem solar cells. However, the development of flexible versions of these cells has been understandably slower.

Improving light absorption in the ultrathin silicon bottom cells, without compromising their flexibility, has proved to be challenging.

In a new paper, scientists from the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences have provided details on their new flexible perovskite/silicon tandem solar cell. 

It is the first flexible perovskite/silicon tandem solar cell based on ultrathin silicon, with a thickness of roughly 30 µm. A µm is a micrometer, which is equivalent to one millionth of a meter.

The scientists were able to significantly improve the flexibility of the solar cell’s silicon substrate without reducing light absorption. They reduced wafer thickness and also adjusted the feature sizes of light-trapping textures.

They also capped the perovskite top cells, which improved the mechanical durability of the material. This addressed concerns over fractures in the surface of the solar cell.

New flexible solar cell efficiency record

In tests, the scientists showed that their flexible perovskite/silicon tandem solar cell achieved a certified stabilized efficiency of 22.8 percent. That is a record efficiency for flexible solar cells. 

Their flexible solar cell also has a power-to-weight ratio of 3.12 W g−1. Crucially, it also has a high bending durability. It maintains 98.2 percent of the initial performance after undergoing 3,000 bending cycles.

The new study showcases the feasibility of flexible perovskite/silicon tandem solar cells, which could open up a whole host of new applications in different fields. These include use as solar panels on sea vessels, for lighting in outdoor areas, and as a power source on windows.

According to a report from SciTechDaily, The study was funded by the National Natural Science Foundation of China, the National Key Research and Development of China, and The Key Research and Development Program of Ningbo.

In February, scientists from the Jiangsu University of Science and Technology (JUST) in China announced the development of silicon-based solar cells. While these solar cells were thinner than a sheet of paper, their efficiency was lower.