Newly developed light-emitting diodes capable of producing ultraviolet light offer a cheaper, more stable, and more durable alternative to current fluorescent lamps.
In a scientific first, researchers at the Norwegian University of Science and Technology (NTNU) successfully produce ultraviolet light using a surface made of graphene.
The process, which was long thought to be impossible, may soon lead to the creation of newer and better forms of lighting for general use.
"We've created a new electronic component that has the potential to become a commercial product," study co-author Ida Marie Høiaas explained.
"It's non-toxic and could turn out to be cheaper, and more stable and durable than today's fluorescent lamps."
The researchers hope that if they succeed in making the LEDs more efficient and affordable, the devices could eventually become commonplace in many people's homes. This could help increase the market potential of their UV-emitting lights significantly.
Making UV Lamps Safer To Use
Ultraviolet light is commonly associated with various health risks such as skin cancer. However, it also has certain potential benefits, according to the researchers.
One example of this is UVC light, a form of UV that produces short wavelengths capable of destroying microbes such as viruses and bacteria. This can help keep surfaces and medical equipment clean and even purify the air and water for human consumption.
UVC light can be reproduced using special lamps, though many of these devices depend on mercury to function. With the United Nations already taking steps to eliminate the production and use of mercury, engineers might have a hard time making UVC lamps moving forward.
To solve this problem, the NTNU team decided to add a layer of graphene to its new LEDs to mitigate the negative effects of ultraviolet light.
Graphene is described as an ultra-thin yet highly durable crystalline material made from a single layer of carbon atoms.
Scientists have successfully grown aluminium gallium nitride (AlGaN) on graphene lattices. Atoms of gallium and aluminium were carefully placed on a graphene substrate and exposed to nitrogen plasma while inside high-temperature vacuum chamber. The entire process is called molecular beam epitaxy (MBE).
The NTNU researchers have collaborated with colleagues at Sophia University in Tokyo, Japan, to carry out the MBE process needed for the experiment. They later added gold and nickel contacts to the graphene and nanowires.
The device is able to emit UV light whenever power is allowed to flow through it. The resulting light produced from the nanowires is able to shine through the glass and graphene materials.
Potential Uses Of UV LEDs
The market for UVC-based products is expected to increase by $700 million over the next few years. The growing popularity of such devices and the eventual phasing out of mercury use could help the market increase by as much as 40 percent every year.
The NTNU researchers are hoping that their new LEDs could lead to better UVC products. They have already teamed up with tech company CrayoNano to develop an industrial platform for their UV technology. The firm is a spinoff of the university's nano research team.
CrayoNano is looking at creating cheaper and more energy-efficient UVC LEDs that can one day replace fluorescent lights on the market.
The findings of the Norwegian University of Science and Technology study are featured in the journal Nano Letters.
