Scientists develop ‘air stable’ perovskite at more than 19% efficiency

Scientists from South Korea’s Chonnam National University have developed a method, named co-precipitation, to develop a uniquely composed perovskite layer for solar cells.

The lead-based perovskite cell utilizes nanoporous nickel oxide as a hole transport layer (HTL), and formamidinium lead iodide and methylammonium lead bromide as the perovskite layer. An electron transport layer (ETL) of an organic/inorganic zinc oxide compound also serves to protect the perovskite layer from exposure to air, which can cause it to degrade.

According to research published in the journal Materials Today, preliminary testing of the devices yielded a 19.1% conversion efficiency, four-fifths of which was sustained after five months in use.

“We successfully optimized the metal oxide based HTL and ETL protecting layers for highly efficient perovskite absorber by a simple method which can make air-stable photovoltaics,” says co-author Dr. Sawanta Mali. “Our main goal is to solve the problem of the tedious process of making conventional additive-doped, highly expensive, unstable HTLs by replacing low-cost, inorganic air-stable p and n-type metal oxides.”

While the technique has so far only been used in the laboratory, the paper’s corresponding author, Chang Kook Hong is keen to stress his belief that it could be scaled up. “Large-scale device fabrication should be possible with this device architecture,” he says.