Startup improves perovskite solar cells with aerosol

News | January 1, 2024

By Peter Clarke

Optoelectronics Analog

Aerosolar Ltd. a UK startup is developing a method to improve the formation and stability of low-temperature-annealed perovskite solar cells.

The company has been awarded a £50,000 grant by Innovate UK to build a commercial-scale reactor for its process, which could enable the production of flexible solar cells for use indoors and on cars and buildings.

Aerosolar is a spin-off from Queen Mary College at the University of London formed to bring to market work conducted by Professor Joe Briscoe and a team of researchers. The company was founded in July 2022.

The majority of solar cells are made of silicon but this requires processing temperatures of 1,000 degrees C. Other materials such as methylammonium lead triiodide (MAPbI3), formamidinium lead triiodide (FAPbI3) can be formed from a chemical solution at around 100-150 degrees C. They are therefore much less expensive to produce. While conversion efficiencies of 25 percent have been achieved these perovskites often have large numbers of crystal dislocations and can be susceptible to decomposition in reaction to moisture and oxygen.

Briscoe and his team are investigating an aerosol-assisted annealing process.

An aerosolised solution is passed over the heated perovskite sample during the annealing process. This creates larger grains and facilitates processing at a lower temperature (100 degrees C) compared to direct thermal annealing. The aerosol solution is a mixture of dimethylformamide (DMF) and methylammonium chloride (MACl).

The treatment is also found to improve the low-light response of perovskite’s by a factor of two. This is a useful development for practical deployment as many hours in the day and many months of the year offer weak sunlight. It could also help enable in-door applications powered by artificial light.

The team is working to test the longevity of the benefits and to apply the process to commercial-scale samples.