A personal handheld device that emits a high-intensity ultraviolet light to disinfect surfaces by killing Covid-19 may be feasible, according to researchers at Penn State, the University of Minnesota, the University of Tokyo and Tohoku University.

UV radiation in the 200 to 300 nanometre range is known to destroy the virus and make it incapable of reproducing or infecting. Devices that can emit these levels are typically expensive mercury-containing gas discharge lamps, which require high power, have a relatively short lifetime and are too bulky for personal use.

The solution is to develop high-performance, UV light emitting diodes, which would be portable, long-lasting, energy efficient and environmentally benign. While these LEDs exist, applying a current to them for light emission is complicated by the fact that the electrode material also has to be transparent to UV light.

Theoretical predictions from the US researchers pointed to the material strontium niobate as a UV transparent conductor, which was then tested at the Japanese universities.

Penn State doctoral candidate Joseph Roth said: “We immediately tried to grow these films using the standard film-growth technique widely adopted in industry, called sputtering. We were successful.”

The researchers are now looking into how to integrate strontium niobate into UV LEDs at low cost and high quantity, to develop more practical UV light disinfectant devices.