Ultraviolet (UV) light is a commonly used method for killing bacteria, but could it help with disinfecting areas contaminated with COVID-19? A breakthrough discovery of a new class of transparent conductors could be the answer.
Two UV infection control methods of killing bacteria currently exist, which use chemicals or ultraviolet radiation exposure as a form of disinfectant, using a 200 to 300 nanometre range. However, in order to kill the COVID-19 virus very high levels of ultraviolet light is required, which can be very costly.
Now, researchers from Penn State and the University of Minnesota have used the recent discovery of a class of transparent conductors that could allow for high levels of UV light that would kill the virus.
If scaled up successfully, the researchers believe that UV light could be used to disinfect public areas such as public transport, aeroplanes, and sports arenas.
Current UV devices fall short
The researchers believe that a handheld UV light device that emits high-intensity rays could help to kill the novel virus.
Roman Engel-Herbert, Penn State associate professor of materials science, physics and chemistry, said: “You have to ensure a sufficient UV light dose to kill all the viruses. This means you need a high-performance UV LED emitting a high intensity of UV light, which is currently limited by the transparent electrode material being used.”
To solve the problem the scientists wanted to develop high performance, portable diodes that can have a current applied to them for light transmission – however, they needed to be transparent to UV light. Finding the correct material was vital, and the scientists believed a recently discovered class of transparent conductors could offer the solution.
The material – strontium niobite – was provided by Japanese collaborators, which was then tested by the Minnesota and Penn State teams as transparent UV conductors.
Developing the conductors
Joseph Roth, doctoral candidate in Materials Science and Engineering at Penn State, commented: “There is currently no good solution for a UV-transparent electrode. Right now, the current material solution commonly employed for visible light application is used despite it being too absorbing in the UV range. There is simply no good material choice for a UV-transparent conductor material that has been identified.
“We immediately tried to grow these films using the standard film-growth technique widely adopted in industry, called sputtering. We were successful.
“While our first motivation in developing UV transparent conductors was to build an economic solution for water disinfection, we now realise that this breakthrough discovery potentially offers a solution to deactivate COVID-19 in aerosols that might be distributed in HVAC systems of buildings.”