Percistand, a research consortium, has claimed 25% power conversion efficiency for a tandem thin-film solar cell over an area of 1cm² which the team believes is the first time these wafer thin cells have produced as much energy as traditional solar cells.
Led by Belgian technology institute imec, the 12 international member consortium said this is not yet the upper limit of the thin-film solar cells it is working on.
What helped in achieving this efficiency level is the use of two different materials, that were not identified, laid on top of each other that were improved upon by various partners. "In recent weeks we've combined the best bottom and top cells, which is how we have already achieved this high efficiency level of 25%. Our ambition now is to generate an energy efficiency of 30% within the next three years," explains Prof Bart Vermang, coordinator in the Percistand consortium.
As of now, the researchers are figuring out a cost-efficient way to combine the two layers in a module.
Vermang said the thin film solar cells developed by the team can be used to create solar panels in all sizes and colors so that these can be integrated within the facade of the roofs. These thin film cells will cost less, 'even cheaper than the traditional ones' since these require less material. A business model is being prepared by the team which should be ready by the end of the project post which the cells can be sold commercially.
Within the next 8 years, the team hopes to have these thin film solar cells available for the public to buy.
However, it is likely the two non-identified layers are perovskite and CIGS technologies. In September 2018, imec reported 24.6% conversion efficiency for a perovskite/CIGS tandem cell produced in partnership with EnergyVille and Solliance, partners of the Percistand consortium (see Higher Efficiency For Imec's nPERT & Tandem CIGS Cell).