Researchers Develop Safer, Longer-lasting Vacuum Ultraviolet Lamps

Researchers from Japan have created a solid-state lamp that operates in vacuum ultraviolet (VUV) regions. The latest kind of UV lamp is cheap, light and easy-to-manufacture.

According to researchers, the devices emit UV light of wavelength 140 to 220 nanometers, which is the shortest wavelength ever recorded in these lamps. The wavelength falls within vacuum-UV light.

Light of this wavelength travels in vacuum, and absorbed by oxygen in the air.

Devices emitting vacuum-UV light are used to clean medical equipment and semiconductor substrates. Vacuum UV attacks oxygen containing molecules and creates reactive oxygen radicals. These radicals can destroy living cells such as microbes inhabiting the surface.

A major drawback of VUV lamps is that they use toxic gases that can harm people. These lamps are also bulky, expensive, use a lot of power and become hot with extended use.

Now, researchers at Nagoya Institute of Technology and colleagues have developed lamps using solid-state phosphor. The phosphor was made using a thin film of the compound KMgF3.

According to the researchers, the latest lamp is cheap to manufacture and easy to handle.

"Our lamp is a promising light source in terms of lifetime, size, heat conduction and stability," said Shingo Ono of the Nagoya Institute of Technology in Japan, who led the research, according to a news release. "[It] has the potential to be an excellent alternate light source to low-pressure mercury lamps, excimer lamps and deuterium lamps."

For the study, researchers had to free phosphor from a compound containing fluoride, which is an extremely corrosive chemical. Researchers found that pulsed laser deposition, which works by adding chemicals layer-by-layer using lasers, was a safer method of fabricating phosphor.

The study was published in the journal APL-Materials and was supported by Japan Society for the Promotion of Science (JSPS), Nippon Sheet Glass Foundation, and Nanotechnology Platform Program.