Printed flexible solar cells expand possibilities for photovoltaics

CSIRO scientists have led an international team in a significant renewable energy breakthrough by printing efficient solar cells on long rolls of plastic.

The flexibility of these cells, which are entirely printed from inks onto thin plastic films, radically increases the types of location where they can be used.

In contrast to silicon solar panels, which are rigid and heavy, these lightweight and portable solar cells can be deployed across urban construction, mining operations, emergency management, disaster relief, space, defence and personal electronics.

The team demonstrated performances for the cells of 15.5% efficiency on a small scale and 11% for a 50 cm² module — a record for fully printed solar cells. The achievement comes after more than a decade’s worth of research and development.

“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,” said Dr Anthony Chesman, CSIRO’s Renewable Energy Systems Group Leader.

“We’ve solved several engineering problems to achieve record results across a large surface area of interconnected modules.”

CSIRO’s Renewable Energy Systems Group Leader, Dr Anthony Chesman.

Chesman said that roll-to-roll printing allowed for the solar cells to be manufactured on very long, continuous rolls of plastic, which can dramatically increase the rate of production.

“As these methods are already widely used in the printing industry, this makes their production more accessible for Australian manufacturers,” he said.

“The successful commercialisation of printed flexible solar cells has the potential to create significant economic and environmental benefits for Australia and the world.”

The team used an automated system to speed up their research and produce a comprehensive dataset.

“We developed a system for rapidly producing and testing over 10,000 solar cells a day — something that would have been impossible to do manually,” said CSIRO Principal Research Scientist Dr Doojin Vak.

“This allowed us 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,” he explained.

Lead author and CSIRO Principal Research Scientist Dr Doojin Vak.

CSIRO’s printed solar incorporates an advanced material called perovskite, making it 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,” Vak said.

“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.”

While acknowledging that perovskite solar cells currently lag behind silicon solar panels in efficiency and lifetime when produced at scale, Chesman believes the application of flexible panels will be very different.

“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.”

The collaborative project involved researchers from the University of Cambridge, Monash University, the University of Sydney and the University of New South Wales, with findings published in Nature Communications. The research received funding from ARENA as part of its Research and Development Program – Solar PV Research.

CSIRO is actively seeking industry partners to further develop and commercialise the technology.

Top image caption: More than a decade’s research and development has culminated in this world-first efficiency outcome for CSIRO’s printable flexible solar team.