Carbon dots made from hair boost stability of perovskite solar cells
Over the past decade or so, gains in efficiency have seen perovskite solar cells become a highly promising technology in the realm of renewable energy, quickly coming to match or even outdo the performance of the monocrystalline silicon solar cells widely used today. Holding them back, however, are intrinsic instability issues and a vulnerability to the elements, which has prevented their mainstream adoption. Scientists in Australia believe they may have found a solution to these problems hiding in hair swept up from the floor of a local barbershop.
This breakthrough in solar cell research actually stems from earlier work carried out at the Queensland University of Technology (QUT), where scientists were able to use human hair from barber shops to help create flexible OLED displays.
This technology hinges on the fact that hair is rich in carbon and nitrogen, which are valuable properties when it comes to engineering light-emitting particles. The scientists burned the hair at 240 °C (464 °F) to break it down and reduce it to a material with both carbon and nitrogen embedded in its molecular structure.
These resulting carbon nanodots piqued the interest of fellow QUT scientists working in perovskite research, who decided to integrate them into solar cells out of curiosity. In doing so, the team found that the nanodots formed a wave-like layer on the perovskite surface, which acted as a protective buffer to preserve their function.
“It creates a kind of protective layer, a kind of armor,” says Professor Hongxia Wang, who led the research. “It protects the perovskite material from moisture or other environmental factors, which can cause damage to the materials.”
Further to improving the stability side of things, the scientists report that incorporating the carbon nanodots into the perovskite solar cells also improved power conversion efficiency. In addition to boosting stability and performance, the carbon nanodots made from barbershop waste also promise a low-cost and sustainable manufacturing process for what could become a key component of next-generation solar cells.
“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," says Wang. “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 commercialization. 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."
The study was published in the Journal of Materials Chemistry A, while the video below offers an overview of the research.