Researchers in Switzerland have set an efficiency record for a new type of solar cell that rivals satellite-grade solar panels at a fraction of the cost.
A team at the Ecole Polytechnique Fédérale de Lausanne (EPFL), together with the Swiss Center for Electronics and Microtechnology (CSEM), achieved an efficiency rate of 30.02 per cent with the triple-junction device, beating the previous record of 27.1 per cent.
The breakthrough combined conventional silicon cells with perovskite, which has been hailed as a ‘miracle material’ for its ability to push efficiencies beyond standard limits.
“We show that with clever design and processing, we can approach performance levels traditionally reserved for the most expensive III–V multi-junction solar cells used in space, which are composed of multiple semiconductor layers,” said Kerem Artuk, a researcher at CSEM, who worked on the breakthrough.
“These can reach up to 37 per cent efficiency, and cost around 1,000 times more than terrestrial cells per watt. Our approach opens the door to a new generation of industrially viable, high-efficiency multi-junction photovoltaics.”
Combining perovskite with silicon is not only more cost efficient, it also allows more of the solar spectrum to be captured and converted into electricity.
These benefits have made the material increasingly important for photovoltaic research, however they have previously proved difficult to scale beyond a laboratory setting.
Upgrades to the triple-junction design have helped improve both the performance and the resilience of these solar cells in recent years.
“Our first demonstration in 2018 had only 13 per cent efficiency, so reaching over 30 per cent efficiency today in a triple-junction device is a remarkable achievement,” said Christophe Ballif, who heads the Photovoltaics and Thin-Film Electronic Laboratory at EPFL.
“Triple-junction solar cells have an even higher efficiency potential compared to single junction and tandem – well above 40 per cent.”
The findings were published in the journal Nature this week, in a paper titled ‘Triple-junction solar cells with improved carrier and photon management’.
