How can human hair boost perovskite solar cell performance?

Researchers from the Queensland University of Technology (QUT) have used carbon dots, created from human hair waste sourced from a Brisbane barbershop, to create a kind of ‘armour’ to improve the performance of cutting-edge solar technology, with their results published in the Journal of Materials Chemistry A.

Perovskite solar cells, a relatively new photovoltaic (PV) technology, are seen as the best PV candidate to deliver low-cost, highly efficient solar electricity in coming years. They are as effective at power conversion efficiency as the current commercially available monocrystalline silicon solar cells, and as they are flexible, they could be used in scenarios such as solar-powered clothing, backpacks that charge your devices on the go, and even tents that could serve as standalone power sources. The challenge for researchers in this area is to make the technology cheaper and more stable.

Last year, QUT Associate Professor Prashant Sonar led a research team that turned hair scraps into carbon nanodots by breaking down the hairs and then burning them at 240°C. In that study, the researchers showed the carbon dots could be turned into flexible displays that could be used in future smart devices.

The latest study saw QUT Professor Hongxia Wang’s research team, working with Prof Sonar’s group, use the carbon nanodots on perovskite solar cells out of curiosity. Prof Wang’s team had previously found that nanostructured carbon materials could be used to improve a cell’s performance; after adding a solution of carbon dots into the process of making the perovskites, they found the carbon dots forming a wave-like perovskite layer where the perovskite crystals are surrounded by the carbon dots.

“It creates a kind of protective layer, a kind of armour,” Prof Wang said.

“It protects the perovskite material from moisture or other environmental factors, which can cause damage to the materials.”

The study found that perovskite solar cells covered with the carbon dots had a higher power conversion efficiency and a greater stability than perovskite cells without the carbon dots. This is a major breakthrough for Prof Wang, who has been working with perovskite cells since they were invented about a decade ago, with the primary objective of developing cost-effective, stable PV materials and devices.

“Our final target is to make solar electricity cheaper, easier to access, longer lasting and to make PV devices lightweight because current solar cells are very heavy,” Prof Wang said.

“The big challenges in the area of perovskite solar cells are solving stability of the device to be able to operate for 20 years or longer and the development of a manufacturing method that is suitable for large-scale production.”

Image caption: Professor Hongxia Wang.

Please follow us and share on Twitter and Facebook. You can also subscribe for FREE to our weekly newsletter and bimonthly magazine.