Carbon Dots From Human Hair Used to Boost Perovskite Solar Cells

Researchers have used carbon dots created from human hair to create a kind of “armour” to improve the performance of perovskite solar cells

Researchers at the Queensland University of Technology (QUT) in Australia 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. In a study published in the Journal of Materials Chemistry A, the researchers led by Professor Hongxia Wang in collaboration with Associate Professor Prashant Sonar of QUT’s Centre for Materials Science showed the carbon nanodots could be used to improve the performance of perovskites solar cells.

This is the second major piece of research to come as a result of a human hair derived carbon dots as multifunctional material. Last year, Associate Professor Prashant Sonar led a research team, including Centre for Materials Science research fellow Amandeep Singh Pannu, that turned hair scraps into carbon nanodots by breaking down the hairs and then burning them at 240 degrees celsius. In that study, the researchers showed the carbon dots could be turned into flexible displays that could be used in future smart devices.

In this new study, Professor Wang’s research team, including Dr. Ngoc Duy Pham,  and Pannu, working with Professor Prashant Sonar’s group, used the carbon nanodots on perovskite solar cells out of curiosity. Professor 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, Professor Wang’s team 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,” Professor 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.

Professor Wang has been researching advanced solar cells for about 20 years, and working with perovskite cells since they were invented about a decade ago, with the primary objective of developing cost-effective, stable photovoltaics materials and devices, to help solve the energy issue in the world.

“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,” Professor Wang added.

Perovskites solar cells, a relatively new photovoltaic technology, are seen as the best PV candidate to deliver low-cost, highly efficient solar electricity in coming years. They have proven to be as effective in power conversion efficiency as the current commercially available monocrystalline silicon solar cells, but the hurdles for researchers in this area is to make the technology cheaper and more stable. 

The big challenges in the area of perovskite solar cells, according to Wang, 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. Currently, all the reported high-performance perovskite solar cells have been made in a controlled environment with extremely low level of moisture and oxygen, with a very small cell area which are practically unfeasible for commercialisation.

“To make the technology commercially viable, challenges for fabrication of efficient large area, stable, flexible, perovskite solar panels at low cost needs to be overcome. This can only be achieved through a deep understanding of the material properties in large-scale production and under industrially compatible conditions,” the Professor said.

Going forward, Professor Wang is particularly interested in how perovskite cells could be used in the future to power spacecrafts.