MiaSolé, part of the Hanergy Thin Film Power Group, and the European Solliance Solar Research established a new world-record power conversion efficiency of 23% on a flexible solar cell. The solar cell combines a flexible semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.
The tandem cell has the potential for high conversion efficiency exceeding single junction solar cell performance thanks to tunable and complementary bandgaps of these individual thin-film solar cells.
In order to realize maximum conversion efficiencies, the absorption properties of the top perovskite cell and of the bottom CIGS cell should be tuned to complement each other. The perovskite solar cell was deposited on a transparent and flexible substrate, employed transparent conductive electrodes, and was optimized for maximum visible light conversion efficiency and infrared light transparency to allow the majority of infrared light to reach the bottom CIGS cell.
The CIGS bottom cell was developed by MiaSolé Hi-Tech, a wholly owned subsidiary of Hanergy, located in Silicon Valley, California. The CIGS cell used in this tandem architecture is based on a commercially available high-efficiency flexible solar cell technology fabricated on lightweight stainless-steel foil using a proprietary high throughput roll-to-cell sputtering process. Recently, MiaSolé reported a flexible large-area-certified module efficiency of 17.44%.
As a result of the combined expertise of MiaSolé in CIGS development and manufacturing and the Solliance team in the area of perovskite technology, a new record efficiency flexible perovskite/CIGS tandem cell was produced.
“A highly efficient flexible hybrid solar cell is an outlook on how perovskite solar cell technology can innovate the established solar technology, leading to a different application area with improved performance,” said to Sjoerd Veenstra, program manager for perovskite-based solar cells at Solliance.
“This significant tandem cell performance gain was achieved through process improvements in the bottom CIGS cell,” added Dmitry Poplavskyy, director of technology at MiaSolé Hi-Tech. “These process changes, implemented by MiaSolé, enable high-efficiency CIGS cells with the spectral response better matched to the top perovskite cell. Further improvements in spectral matching as well as overall higher CIGS cell efficiency are expected to push the tandem architecture well beyond 23%.”
News item from MiaSolé