Researchers at Swansea University in Wales, United Kingdom have established a low-cost and scalable carbon ink formulation capable of unlocking the potential for the manufacture of perovskite solar cells at scale.

The team said they used slot die coating in a roll-to-roll (R2R) process and developed a way to create a “fully printable” perovskite photovoltaics (PV).

They searched for an alternative to the gold electrode that is typically applied using an expensive and slow evaporation process.

The study found devices with carbon electrodes provided similar photovoltaic performance to the conventional evaporated gold electrodes with power conversion efficiencies of 13-14% and the additional benefits of outperforming at higher temperatures and having better long-term stability.

The new fully R2R-coated device, which was printed onto a 20-meter-long flexible substrate, produced a stabilized power conversion efficiency of 10.8%.

The researchers said the most important part of this project was coating the carbon entirely, R2R, a new process of working with perovskite photovoltaics, which helps to scale up easier.

“The key was identifying the right solvent mix, one which dries as a film without dissolving the underlying layer,” said David Beynon, Senior Research Officer.

The researchers, through X-ray diffraction analysis, identified that carbon electrode ink is capable of this when formulated with an orthogonal solvent system.

The layer can be applied continuously and compatibly with the underlying layers at a low temperature and high speed.

Photovoltaic Research Lead Trystan Watson said: “The ability to produce a fully working device entirely in-line makes high-volume manufacturing easier and more economical and is a big step towards their commercialization. It unlocks the idea of a manufacturing process where a solar ink is added to one end and a solar cell emerges from the other.”

In four years, this innovative method for PV has been designed, assessed, and improved, making the possibility of printing and installing millions of meters of solar cells across the globe closer than ever.

The team said the next challenge in printed PV is to prove to people that the tech actually works.

In order to do this, the researchers said they need to start making something that really looks like a solar panel.

Once this is done, they can install them on buildings and understand how close they are to delivering on the promise of UK-based manufacturing of green renewables.

Recently, researchers at the Shandong Academy of Medical Sciences, China, and Kyushu Institute of Technology, Japan, upcycled crab shells into porous, carbon-filled materials with a wide variety of uses, including using the crab carbon to create anode materials for sodium-ion batteries.

Earlier in the month, researchers at South Korea’s Ulsan National Institute of Science and Technology developed a perovskite solar cell by using alkylammonium chloride to control the formation of defects in the perovskite layer.