Perovskite silicon tandem solar cells are hopefuls for producing solar electricity more cheaply and with less resource consumption than pure silicon cells. Now, for the first time, the barrier of 30 percent efficiency in converting light into electricity has been broken for this type of solar cell. This was announced by the Centre for Electronics and Microtechnology (CSEM) in Neuchâtel and the EPFL.

According to the report, the researchers achieved two world records at the same time: one for smooth solar cell architecture (efficiency 30.93 percent) and one for textured silicon surfaces (31.25 percent). They conducted the experiments with solar cells one square centimetre in size.

The two world records were certified by the independent National Renewable Energy Laboratory (NREL) in the USA.

A "psychological hurdle" overcome

With the energy yield of over thirty percent, a "psychological hurdle" has been overcome, said Christophe Ballif, Director of the Photovoltaic Laboratory at EPFL and the CSEM Centre for Sustainable Energy. This value had already been achieved with other materials, but with those too expensive to support the energy transition, he said. "Our results show for the first time that the 30 per cent barrier can also be broken with low-cost materials and processes, opening up new future prospects for photovoltaics," the researcher said.

Further research and development is now needed to achieve a stable energy yield even on larger surfaces, added Quentin Jeangros from CSEM.