CSIRO develops highly efficient roll-to-roll printed solar cells

Scientists from CSIRO have reportedly set a new efficiency record for fully roll-to-roll printed solar cells. Printed onto thin plastic films, the lightweight and flexible solar technology could help meet the growing demand for renewable energy by expanding the boundaries of where solar cells can be used.

Where silicon solar panels are rigid and heavy, the printed solar cells are designed to be flexible and portable, meaning they can be deployed in a range of ways across urban construction, mining operations, emergency management, disaster relief, space, defence and personal electronics.

CSIRO’s Renewable Energy Systems Group Leader, Dr Anthony Chesman, said the development is the result of more than a decade’s research. Chesman added that roll-to-roll printing allows for the solar cells to be manufactured on very long, continuous rolls of plastic, which can increase the rate of production.

“CSIRO’s thin and lightweight solar cells are now on the cusp of emerging from the lab to create clean energy in the real world. We’ve solved several engineering problems to achieve record results across a large surface area of interconnected modules. As these methods are already widely used in the printing industry, this makes their production more accessible for Australian manufacturers. The successful commercialisation of printed flexible solar cells has the potential to create significant economic and environmental benefits for Australia and the world,” Chesman said.

CSIRO Principal Research Scientist Dr Doojin Vak said an automated system produced a comprehensive dataset that will pave the way to use machine learning in future research. Vak said the researchers developed a system for rapidly producing and testing over 10,000 solar cells a day; this allowed them to identify the optimal settings for the various parameters in the roll-to-roll process and quickly pinpoint the conditions that deliver the best results. Incorporating an advanced material called perovskite, CSIRO’s printed solar is different from the silicon solar panels found on Australian roofs.

“Perovskites are a class of emerging solar cell material. They’re remarkable because they can be formulated into inks and used in industrial printers. We’ve also alleviated the need to use expensive metals, such as gold, in their production by using specialised carbon inks, which further reduces production costs,” Vak said.

Chesman acknowledged that although the perovskite solar cells currently trail silicon solar panels in efficiency and lifetime when produced at scale, the application of flexible panels could be very different. “As these perovskite solar cells are printed onto plastic films, they are very lightweight, highly flexible and portable. The rigidity and weight of conventional silicon solar panels can make moving them difficult. Our thin, lightweight solar can be easily transported anywhere there is sun. We even sent the solar panels to space last week to test their performance, with a view to further optimise and ultimately provide a reliable energy source for future space endeavours,” Chesman said.

The researchers demonstrated performances for solar cells of 15.5% efficiency on a small scale and 11% for a 50 cm² module. Automatic screening was used to optimise the printing process, with carbon-based inks used to replace gold in the solar cell, thereby reducing the cost while maintaining high performance. Technoeconomic modelling was also used to predict the production cost in Australia. CSIRO is seeking industry partners to further develop and commercialise this technology.

The results were achieved in collaboration with researchers from the University of Cambridge, Monash University, the University of Sydney and the University of New South Wales, and have been published in the journal Nature Communications.

Image caption: Lead author and CSIRO Principal Research Scientist Dr Doojin Vak. Image credit: CSIRO.