Carbon dots from human hair amplify solar cells

Professor Hongxia Wang. Credit: Queensland University of Technology (QUT)

QUT researchers used carbon dots, created from human hair waste from a barber shop in Brisbane, to create a kind of “armor” to improve the performance of state-of-the-art solar technology.

In a study published in Journal of Materials Chemistry A, researchers led by Professor Hongxia Wang in collaboration with Assoc. Professor Prashant Sonar of QUT’s Center for Materials Science showed that carbon nanodots can be used to improve the performance of perovskite solar cells.

Perovskites solar cells, a relatively new photovoltaic technology, are considered the best photovoltaic candidate for the delivery of cheap, highly efficient solar electricity in the coming years. They have been shown to be just as effective in energy conversion efficiency as current commercially available monocrystalline silicon solar cells, but an obstacle for researchers in this field is to make the technology cheaper and more stable.

Unlike silicon cells, they are created with a mixture that is easy to produce, and because they are flexible, they can be used in scenarios such as solar-powered clothing, backpacks that charge your devices on the go, and even tents that can serve as an independent power source.

This is the second major study that followed as a result of carbon dots derived from human hair as a multifunctional material.

Last year, associate professor Prashant Sonar led a research team, including Amandeep Singh Pannu, a researcher at the Center for Materials Science, who turned hair waste into carbon nanodots by breaking hairs and burning them at 240 degrees Celsius. In that study, researchers showed that carbon dots can be turned into flexible screens that can be used in future smart devices.

In this new study, Professor Wang’s research team, including Dr. Ngoc Duy Pham and Mr. Pannu, working with a group of professors Prashant Sonar, out of curiosity used carbon nanodots on perovskite solar cells. Professor Wang’s team previously discovered that nanostructured carbon materials can be used to improve cell performance.

After adding a solution of carbon dots to the perovskite formation process, Professor Wang’s team found carbon dots that form a wave-like layer of perovskite where the perovskite crystals are surrounded by carbon dots.

“It creates a kind of protective layer, a kind of armor,” Professor Wang said.

“Protects perovskite material from moisture or other environmental factors, which can damage the materials.”

The study found that perovskite solar cells covered with carbon dots had higher power conversion efficiency and greater stability than perovskite cells without carbon dots.

Professor Wang has been researching advanced solar cells for about 20 years and has been working with perovskit cells since they were invented about ten years ago, with the primary goal of developing cost-effective, stable photovoltaic materials and devices that help solve the world’s energy problem.

“Our ultimate goal 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 said.

“The big challenges in the field of perovskite solar cells are solving the stability of the device so that it can work for 20 years or longer and developing a production method that is suitable for large production.

“Currently, all reported high – performance perovskite solar cells are fabricated in a controlled environment with extremely low levels of moisture and oxygen, with a very small cell surface area that is virtually unfeasible for commercialization.

“For technology to become commercially viable, the challenges of producing efficient large areas, stable, flexible, low-cost Perov solar panels must be overcome.

“This can only be achieved by a deep understanding of the properties of materials in large-scale production and under industrially compatible conditions.”

Professor Wang is particularly interested in how perovskite cells will be used to power spacecraft in the future.

The International Space Station is powered by four solar fields that can produce up to 120 kW of electricity. But one of the disadvantages of the current space PV technology is the weight of the payload that will take them there.

Although perovskite would be much lighter, one of the challenges for researchers is to develop perovskite cells capable of coping with extreme radiation and a wide range of temperature variations in space – from minus 185 degrees to more than 150 degrees Celsius.

Professor Wang said the solution could take ten years, but researchers continued to gain greater insights in the area.

Currently, Professor Wang’s research team is collaborating with Professor Dmitry Golberg at the QUT Center for Materials Science to understand the properties of perovskite materials in extreme environmental conditions, such as strong electron beam radiation and drastic temperature changes.

“I’m pretty optimistic about how much this technology has improved so far,” Professor Wang said.

The new method of making solar cells from perovskite promises to break the limit of efficiency

More information:
Ngoc Duy Pham et al. Self-installed carbon-wrapped perovskites enable light capture and passivation of defects for efficient and stable perovskite solar cells, Journal of Materials Chemistry A (2021). DOI: 10.1039 / D1TA00036E

Provided by the University of Queensland Technology

Citation: Carbon dots from human hair amplify solar cells (2021, April 8) downloaded April 8, 2021 from

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