Researchers have used hair waste from a barbershop to improve the performance of solar technology.

QUT researchers have used carbon dots, created from human hair, to build a kind of “armour” for perovskite solar cells.

Solar cells made of perovskite are a relatively new photovoltaic technology, but are emerging as the best new PV candidate to deliver low-cost, highly efficient solar electricity in coming years. 

They are already as effective in power conversion efficiency as the current commercially available monocrystalline silicon solar cells, but researchers are still working to make the technology cheaper and more stable.

Perovskite cells are made of easily-manufactured materials, and are flexible enough to be used in devices like solar-powered clothing, backpacks or tents that serve as standalone power sources.

New research is showing that human hair-derived carbon dots are a multifunctional material.

Last year, researchers turned hair scraps into carbon nanodots by breaking down the hairs and then burning them at 240 degrees celsius. 

The study showed the carbon dots could be turned into flexible displays that could be used in future smart devices.

In this new study, scientists used the carbon nanodots on perovskite solar cells out of curiosity. 

After adding a solution of carbon dots into the process of making the perovskites, QUT’s Professor Hongxia Wang 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.

Looking forward, Professor Wang says perovskite cells could be used in the future to power spacecraft.

The International Space Station is powered by four solar arrays, which can generate up to 120 kW of electricity. But one disadvantage of the current technology of space PVs is the weight of the payload to get them there.

While perovskite would be much lighter, one of the challenges for researchers is to develop perovskite cells able to cope with the extreme radiation and broad range of temperature variation in space – from minus 185 degrees to more than 150 degrees Celsius. 

Professor Wang said the solution could be ten years off, but researchers were continuing to gain greater insights in the area.

His team is working to understand the properties of perovskite materials under extreme environmental conditions such as strong irradiation of an electron beam and drastic temperature change.

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

The latest study is accessible here.