Researchers from Germany have set a new world record in solar cell efficiency using the so-called ‘miracle material’ perovskite.
The team from the Universities of Wuppertal, Cologne, Potsdam and Tubingen developed a tandem solar cell using organic and perovskite materials – a combination they hope could one day replace the silicon-based technologies used in conventional solar cells.
The record they set of 24 per cent efficiency was a 4 per cent improvement on the previous tandem cell record, though still falls short of the silicon solar cell record of 26.7 per cent.
The new materials, however, hold far greater potential for improved efficiency in the future, whereas silicon solar cells are now considered “as good as it gets” with an intrinsic limit of around 29 per cent.
The new materials also hold the benefit of requiring significantly less material and energy for their production compared to silicon cells, making them even more sustainable.
Perovskite has been hailed for its ability to significantly improve everything from renewable energy production to ultra-high-speed communications, with materials science professor Z. Valy Vardeny calling it a “miracle material” in 2017.
Its capacity to transform the solar industry has only begun to be realised in recent years, with its sunlight-to-energy efficiency improving from around 3 per cent just a few years ago.
The use of different semiconductor materials in the solar cell allows them to absorb different ranges of the solar spectrum, with perovskite suited to efficiently absorbing near-infrared light.
“To achieve such high efficiency, the losses at the interfaces between the materials within the solar cells had to be minimised,” said Dr Selina Olthof from the University of Cologne’s Institute of Physical Chemistry.
“To solve this problem, the group in Wuppertal developed a so-called interconnect that couples the organic sub-cell and the perovskite sub-cell electronically and optically.”
A study detailing the breakthrough, titled ‘Perovskite/ organic tandem solar cells with indium oxide interconnect’, was published in the journal Nature on Wednesday.