22 November 2017
Solliance raises efficiency records for roll-to-roll perovskite solar cells and modules
Solliance - a cross-border Dutch-Flemish-German thin-film photovoltaic (TFPV) solar energy R&D consortium in the ELAT (Eindhoven-Leuven-Aachen) region - has achieved record cell-level conversion efficiency of 13.5% and module-level aperture-area conversion efficiency of 12.2% for perovskite-based photovoltaics using industrially applicable, roll-to-roll (R2R) production processes.
Following its previous cell record of 12.6% announced in March, Solliance reckons that the latest record is another step towards the rapid introduction of this new type of efficient solar cell technology.
Perovskites solar cells 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 its partners aim to speed the market introduction of this technology by developing 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, Solliance demonstrated R2R processes for both the electron transport and perovskite layers of the cells that make up the 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 levels.
After selecting two foil zones each about 10m long with visually good perovskite quality but with different R2R processing settings, 20 individual 0.1cm2 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% higher than the previously reported run in March.
In addition, for each zone six 2cm x 2cm (4cm2) aperture modules, four 3.5cm x 3.5cm (10.5cm2) aperture modules and one 13cm x 12.3cm (160cm2) 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 4cm2 showed a maximum aperture stabilized efficiency of 12.1%, with an average of 11.1% across the six modules. The larger modules of 10.5cm2 achieved a maximum aperture stabilized efficiency of 12.2 % with an average of 11.0% across the four modules. Last but not least, the large module of 160cm2 (pictured) achieved an aperture stabilized efficiency of 10.1%.
Picture: Solliance’s large 160cm2 module, which achieved aperture stabilized efficiency of 10.1%.
All processing steps used low-cost materials and scalable processes at temperatures below 120°C, highlighting 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,” says Pim Groen, professor of SMART materials at the Technical University of Delft and program manager at Holst Centre/Solliance.
“The metals project at Solliance is hitting its targets,” notes Richard Caldwell., managing director of Greatcell Solar (formerly Dyesol), which develops and commercializes perovskite solar cell (PSC) technology. “The successful translation of this PSC technology from the laboratory to the factory will open up massive commercial opportunities,” he believes, highlighting 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.”
After delivering incredible efficiencies in lab-scale photovoltaic cells, the challenge now is to scale up perovskite cells to larger modules with high efficiency and long lifetime at low cost. Solliance says that this demonstration of scalable roll-to-roll and sheet-to-sheet processes for the deposition of active layers and cell interconnections shows it is well placed to realize this upscaling. “We are confident of quickly boosting efficiencies above 15% for modules up to 30cm x 30cm,” says Ronn Andriessen, program director at Solliance. “Our research shows that optimizing materials and processes is steadily improving the stability of perovskite devices under real-life operational conditions.”
Solliance’s research on the development and applications of perovskite-based PV modules is carried out in conjunction with industrial partners Greatcell Solar Limited, Solartek and Panasonic.