Richard Musgrove
Swedish researchers have invented a fully-recyclable perovskite solar cell that may provide a solution to the growing problem of solar panel waste.
All renewable technologies have a life span — with solar panels it’s 25 to 30 years — which means our solar waste pile is rapidly becoming mountainous. Just 17 % of solar panel components were recycled in Australia in 2023, specifically the aluminium frames and junction boxes. The remaining 83% (glass, silicon and polymer back sheeting) was shuttled out to landfill. Other countries do better; France’s ROSI was an early starter in what could be a $2b market by 2050.
Linköping University researchersmay have a solution — fully recyclable perovskite solar cells.
These cells are also flexible, transparent and inexpensive — who needs aluminium frames when your PVs are stuck to your windows?
“There is currently no efficient technology to deal with the waste of silicon panels. That’s why old solar panels end up in the landfill,” says coauthor, Xun Xiao, at the Department of Physics, Chemistry and Biology (IFM) at Linköping University (LiU).
“Huge mountains of electronic waste that you can’t do anything with.”
Perovskites used in photovoltaic solar cells are ‘metal-halide perovskites’ — made from organic ions, metals and halogens. Such cells’ active layers are much thinner and cheaper than those of conventional silicon PV and show efficiencies of more than 26%, comparable with silicon PVs (20% – 22%).
But perovskite PVs are not yet produced at scale.
Recyclability is the key.
“We need to take recycling into consideration when developing emerging solar cell technologies,” says Professor Feng Gao, also at IFM at LiU and a co-author. “If we don’t know how to recycle them, maybe we shouldn’t put them on the market at all.”
Niansheng Xu, postdoc at LiU, and co-author, adds: “There are many companies that want to get perovskite solar cells [PSCs] on the market right now, but we’d like to avoid another landfill. In this project, we’ve developed a method where all parts can be reused in a new perovskite solar cell without compromising performance.”
“We can recycle everything – covering glasses, electrodes, perovskite layers and also the charge transport layer,” says Xiao.
The team’s solvent of choice for breaking down PSCs? Water — not the more commonly-used ‘dimethylformamide’ (DMF), a carcinogenic chemical also found in paint solvents.
And they can recover high-quality perovskites from the water solution, repeatedly.
Lifespan is 30 years for a silicon PV — a small fraction of that for perovskites, so recyclability and environmental friendliness are important. Lead is used to maximise efficiency, which also complicates recycling.
The researchers see their recyclable perovskite innovation as slotting into the energy production mix using existing infrastructure and supply chains.
The research is published in Nature this week.
The promise of recyclable solar cells
