The results of this work, led by the University of Valencia’s Hendrik Bolink and done in collaboration with researchers from École Polytechnique Fédérale de Lausanne, Switzerland, have been published in Nature Photonics.
The solar cell consists of a thin perovskite film sandwiched in between two very thin organic semiconductors and the total thickness of the device is less than half a micrometer.
It is claimed the hybrid organic-inorganic perovskite material can be prepared easily and at low cost. In a statement, Bolink said these devices were prepared with low temperature processes similar to those used in the printing industry, which allows the use of flexible plastic substrates.
It is also possible to make the device semi-transparent, which allows their integration with building facades since they are very thin and light weight. In this way the sun light is filtered, protecting the building interior from intense sun light while simultaneously generating electricity.
Approximately 85 per cent of the solar cells are based on crystalline silicon, an expensive material, whereas the rest use polycrystalline thin film cells mostly made from cadmium telluride/cadmium sulphide. These thin film cells are cheaper to produce but are based on rare, toxic elements.
‘The demonstration of high efficiency in thin film solar cells based on abundantly available and cheap materials like as used in these perovskite based solar cells, allows for an increasing share of solar energy in the mix of renewable resources,’ said Bolink.