Science News

New technique to improve perovskite solar cells

A team of researchers from the United States and China have found a way to make perovskite solar cells more efficient and dependable.

By treating hybrid halide perovskite solar cells with a methyl ammonium bromide solution, researchers minimized material defects and improved performance. The production technique resulted in a boost to the cells’ sunlight conversion efficiency.

Perovskite solar cells have seen marked improvement in their conversion efficiency in recent years, but inconsistencies in the production process and disparity in the skills of lab technicians have resulted in widely varying cell performances.

Without the new technique, most cells feature an efficiency ranging from 15 to 20 percent. The new technique ensures an efficiency of 19 percent.

The application of the methyl ammonium bromide solution triggers what’s called the Ostwald ripening process, whereby smaller crystals are dissolved and deposited onto bigger crystals. The process ensures consistent, pinhole-free perovskite films.

Other methods for growing perovskite cells are less foolproof, and require a great deal of timing. As a result, cells often end up with defective, non-uniform crystals or holes in the film.

“This new chemical approach enhances processing tolerance to the initial perovskite film quality and improves the reproducibility of device fabrication,” researchers wrote in their paper on the breakthrough, published this week in the journal Nature Communications.

The research was carried out by scientists a the Department of Energy’s National Renewable Energy Laboratory and Shanghai Jiao Tong University.