A group of researchers at Queensland University of Technology (QUT) has created a sustainable method for making perovskite solar cells (PSCs) by adding a fluoride ingredient to a water-based solution. This method removes the need for harmful chemicals usually used in PSC production and achieves energy conversion efficiencies above 18%.

PSCs offer great potential for the future due to their efficiency and low costs. However, their widespread use has been hindered by the environmental issues associated with toxic solvents used in production. Using water-based processing is a greener option but has previously resulted in lower device performance.

In their study, QUT researchers introduced lead(II) fluoride (PbF₂) into the water-based precursor solution to control crystal growth and improve film quality. The fluoride additive sped up the creation of the photoactive phase and enhanced crystallization orientation, both crucial for efficient solar energy conversion.

Moreover, the high electronegativity of fluoride ions helped reduce energy losses and improve charge transport by passivating surface defects on perovskite grains.

“With the PbF₂ additive, we achieved an efficiency of 18.1%, compared to 16.3% in the control device,” said Dr. Minh Tam Hoang, a postdoctoral researcher at QUT and co-author of the study. “The improved operational and environmental stability brings us closer to scalable, environmentally-friendly production of PSCs.”

This research presents a successful method to produce stable, efficient PSCs using water-based solvent, making the technology more suitable for commercial use and reducing environmental impact. The study also emphasizes the importance of fluoride-based additives in sustainable energy technologies and green chemistry. The study was recently published in Materials Futures.