The quest to boost the efficiency of silicon solar cells – and further reduce the cost of PV generation – has gained ground this week through an Australia National University-led study.
The ANU team, in collaboration with researchers from the California Institute of Technology, has focused on the way tandem solar cells – one cell on top of the other – are joined together.
The result has been to demonstrate two proof-of-concept perovskite and silicon tandem devices that function without the conventional interlayer between their subcells.
“We have constructed a tandem structure that is unconventional,” said study co-author Dr Heping Shen from the ANU School of Engineering.
“When engineers combine two cells they usually need to have an interlayer to allow electrical charge to be transferred easily between the two cells, so they can work together.”
Co-author Dr Daniel Jacobs explains that, like a club sandwich with extra bread in the middle, this interlayer plays a structural role – but the sandwich would taste better without it.
“We’ve found a new way to simply stack the two cells together so they’ll work efficiently with each other – we don’t need the interlayer, or extra bread, anymore,” he said.
The team says this minimises energy waste and simplifies the solar cell structure, potentially making it cheaper and easier to produce.
“Jointly, our work highlights the potential of emerging perovskite photovoltaics to enable low-cost, high-efficiency tandem devices through straightforward integration with commercially relevant and emerging Si solar cells.”