Ultraviolet lights producing vacuum UV are useful for a wide variety of purposes. Now, researchers in Japan have developed a new inexpensive, environmentally-friendly method of building the devices.
The wavelengths of light created are classified as vacuum-UV light. At these energies, the photons of light can pass through a vacuum, but are quickly converted into other forms by oxygen. Vacuum-UV wavelengths exist in both the most- and least-energetic of all UV frequencies. Interactions between the radiation and oxygen can serve a useful purpose. By striking medical supplies with vacuum-UV light, the electromagnetic radiation turns oxygen atoms into free radicals which then act as a disinfectant, milling microbes.
"Additionally, we obtained a thermal-free and low-power consumption lamp by employing carbon nanofibers (CNFs) as a field emitter. A CNF emitter was easily grown at room temperature and can be grown on flexible materials," researchers wrote in the journal article announcing their results.
Vacuum ultraviolet energy is often used in medical devices, because the waves are converted so quickly by oxygen in the air.
Current equipment to produce vacuum-ultraviolet radiation is large and prohibitively expensive. Manufacture of the devices also requires the use of hazardous materials, which can harm the environment.
"Our lamp is a promising light source in terms of lifetime, size, heat conduction and stability. [It] has the potential to be an excellent alternate light source to low-pressure mercury lamps, excimer lamps and deuterium lamps," Shingo Ono of the Nagoya Institute of Technology in Japan, who directed the research, said.
Researchers created this device by growing a luminescent "phosphor" from a thin sheet of an inexpensive material containing potassium, magnesium, and fluorine. This is the first solid state UV phosphor ever developed.
This new method of designing lights could deliver a new generation of the ultraviolet lights that are small, durable and environmentally friendly. The new phosphor produces no significant heat, and is flexible. Not only could the advance be useful in medicine, but it could be used for a wide variety of electronic applications.
Fluoride can be hazardous to handle, and is highly corrosive. Researchers looking for an environmentally friendly way of producing these devices had to find a method to introduce the substance. To make this happen safely, the group used pulsed laser deposition, a procedure to layer thin films on top of a base material, using focused beams of light.
Development of the new ultraviolet light technology was profiled in the journal APL Materials.
