Solliance achieves 12.6% efficiency for roll-to-roll perovskite solar cells

14 Mar 2017

Fast-growing solar cell technology demonstrated on industrially-applicable roll-to-roll processes.

The Solliance photovoltaic research partnership has announced the successful demonstration of an industrially-applicable roll-to-roll process for the production of solar cells, achieving what the partners claim is a “record 12.6% conversion efficiency” on the cell level. They add that this achievement paves the way towards an accelerated market introduction of this attractive new source of renewable energy.

Solliance is a cross-border Dutch-Flemish-German thin-film research initiative conducting advanced research on the development of perovskite-based PV modules and its applications, with industrial partners Solartek, Dyesol and Panasonic.

Solliance and its research partners focus on using scalable, industrial processes towards the fabrication of larger-area PV modules, which will eventually be suitable for seamless integration in a broad variety of PV systems.

The roll-to-roll (R2R) process was developed for both the electron transport and the perovskite layers on the latest Solliance dual R2R coating line, as developed by Solliance with its partners VDL Enabling Technologies Group, Smit Thermal Solutions and Bosch-Rexroth. The in-line roll-to-roll coating, drying and annealing processes were executed at a linear speed of 5 m/min on a 30-cm wide commercial PET/ITO foil and under ambient conditions.

High volume potential

After applying a newly-developed finishing step, individual solar cells of 0.1cm² achieved efficiencies of up to 12.6%, measured under maximum power point-tracking conditions over five minutes. All process steps on the roll-to-roll line were performed using low-cost materials whilst keeping the process temperatures below 120˚C. The Solliance team says this capability shows the high volume production potential of this emerging thin film PV technology.

“The demonstration of R2R processing at 5 m/min of perovskite layers for solar cells indicates that high-volume production, and hence with an expected very low cost, will be possible in the future”, said Pim Groen, Professor of SMART materials at the Technical University of Delft and Program Manager at Holst Centre/Solliance.

”These results show that the Solliance research partners, with their in-depth know-how on processing of thin film PV devices and their extensive sheet-to-sheet and roll-to-roll pilot production infrastructure, are excellently placed to realize this upscaling.”

VDL ETG has been leading the consortium of equipment manufacturing companies that designed and built the innovative R2R coating line. VDL’s CEO Willem van der Leegte comments: “I am very pleased with this result. It shows that combining process know-how at Solliance with capabilities of high-tech equipment companies in this region can deliver very powerful results that potentially open up completely new business opportunities.”

Richard Caldwell, Solliance’s managing director commented, “Dyesol is very pleased with this breakthrough; we are committed to developing the industry standard for R2R Perovskite Solar Cell (PSC) PV manufacturing in conjunction with Solliance and this result is an important step along this route. This pioneering work confirms that Dyesol and its partners retain a global leadership position in the industrialisation of PSC Technology, and in particular, its continuous R2R processing for flexible BIPV applications.”

Record breakers

The current world record efficiency of a small lab-scale perovskite-based PV cell is 22.1%. Ronn Andriessen, Program Director at Solliance, commented, “The challenge is to upscale perovskite cells to larger sized, industrially-manufacturable modules with high efficiency and long lifetime at low cost.

These 12.6% R2R up-scaled perovskite-based solar cells represent “a first and important step” in this development, Andriessen added. “We are confident that we can quickly boost the up-scaled perovskite-based PV module efficiency above 15% by using low-cost materials and processes.”

With its high power conversion efficiency and flexible and lightweight structure, thin-film perovskite PV technology is considered as a future key technology for the building- integrated photovoltaics (BIPV) market. It can be seamlessly integrated in building elements, on curved surfaces and be semitransparent.

Combining the industrially-applicable manufacturing processes with Solliance’s proprietary back-end interconnection process allows the creation of perovskite-based PV modules with any form and shape and any desired current- voltage output. These properties will enable customized and aesthetic integration of solar modules for infrastructure, building and vehicle-integrated PV products.