Solliance pushes up roll-to-roll perovskite solar cell efficiency

Technology News | November 24, 2017

By Nick Flaherty

Materials & processes Energy Harvesting

The cross-border Dutch-Flemish-German thin-film photovoltaics research initiative saw a cell efficiency record earlier this year, and has also pushed module efficiency to a record 12.2%.

Perovskite materials promise high efficiency from relatively simple production processes, bringing the potential for cheaper, greener energy. Moreover, they can be processed into thin, lightweight and potentially semi-transparent modules for integration into windows or curved construction elements.

Solliance and project partners Greatcell Solar, Solartek and Panasonic are working on the market introduction of the technology with scalable, industrial processes for fabricating large-area modules. The goal is to enable seamless integration in a broad variety of new energy harvesting building blocks for infrastructure, building and vehicle construction and assembly.

In March this year, Solliance demonstrated R2R processes for both the electron transport and perovskite layers of the cells that make up such modules. Now, by further optimizing and re-validating these processes on its dual R2R coating line, Solliance has improved performance at both the cell and module level.

After selecting two 10m long foil zones with a visual good perovskite quality, but with different R2R processing settings, 20 individual 0.1 cm² solar cells were made in each zone. In one zone the maximum stabilized efficiency reached 13.5% (measured under maximum power point tracking conditions over 5 minutes) and in the second zone a maximum of 12.5% was reached. The average stabilized cell efficiency in the best performing zone was about 1 percentage point higher than the previously reported run in March 2017.

For each zone, six 2 x 2 cm (or 4 cm²) aperture modules, four 3.5 x 3.5 cm (or 10.5 cm²) aperture modules and one 13 x 12.3 cm (or 160 cm²) aperture module were produced by implementing a P1P2P3 laser scribe process with 100% yield over all 22 fabricated modules. For the modules prepared from the best performing zone, the smaller modules of 4 cm² showed a maximum aperture stabilized efficiency of 12.1%, with an average of 11.1% across the six modules. The larger modules of 10.5 cm² achieved a maximum aperture stabilized efficiency of 12.2 % with an average of 11.0% across the four modules. The largest module (above) achieved an aperture stabilized efficiency of 10.1%.

All processing steps used low-cost materials and scalable processes at temperatures below 120 °C. This highlights the potential for cost-effective, high-volume production of perovskite solar cells.

“These results show that the developed R2R process is very reproducible over different runs in time, which is very important for future reliable manufacturability,“ said Pim Groen, Professor of SMART materials at the Technical University of Delft and Program Manager at the Holst Centre and Solliance.

“The metals project at Solliance is hitting its targets,” said Richard Caldwell, Managing Director of Greatcell Solar. “The successful translation of this PSC technology from the laboratory to the factory will open up massive commercial opportunities. A particularly pleasing feature of the current progress is the possibility to solar enable commercial and industrial roofing using low-cost R2R processes, thus opening up a whole new space to capture the Sun’s energy, all day, every day.”

The challenge now is to scale up the perovskite cells to larger modules with higher efficiency and longer lifetime at low cost. “This demonstration of scalable roll-to-roll and sheet-to-sheet processes for the deposition of active layers and cell interconnections shows Solliance is excellently placed to realize this upscaling. We are confident of quickly boosting efficiencies above 15% for modules up to 30×30 cm². Our research shows that optimising materials and processes is steadily improving the stability of perovskite devices under real life operational conditions,” said Ronn Andriessen, Program Director at Solliance.

www.solliance.eu

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