Duke University and United States Army scientists have found that a cheap and nontoxic sunburn and diaper rash preventative can be made to produce brilliant light best suited to the human eye.
Duke adjunct physics professor Henry Everitt, chemistry professor Jie Liu and their graduate student John Foreman have discovered that adding sulfur to ultra-fine powders of commonplace zinc oxide at about 1,000 degrees centigrade allows the preparation to convert invisible ultraviolet light into a remarkably bright and natural form of white light.Now, they are working on figuring out how to make a solid version of the system for real world use. “Our target would be to help make solid state lighting with better characteristics than current fluorescent ones,” said Everitt
The researchers said they are producing white light centered in the green part of the spectrum by forming the sulfur-doped preparation into a material called a phosphor. The phosphor converts the excited frequencies from an ultraviolet light emitting diode (LED) into glowing white light. When you think about this it is actually conforting. It’s not glowing ooze, it’s a power source.
The Army has selected the project for priority funding through a competitive In-house Laboratory Independent Research program because of its potential advantages as an energy efficient and safe illumination source. “One of the objectives is to give soldiers efficient lighting that doesn’t run their batteries down,” Everitt said. “They need efficiency, brightness, longevity and ruggedness, and this helps with all of those things.”
It also has some non-brightness related advantages as one of the creators was kind enough to explain. A compound that can be used on faces or babies’ bottoms also has major safety advantages over fluorescent bulbs, which happen to contain toxic mercury. “If a fluorescent bulb gets broken in the course of battle, it exposes soldiers to that mercury in addition to its shattered glass,” Everitt said. It could also have an impact on the enviroment. “I think the biggest payoff for the general public will ultimately be in future energy crises we’re certainly going to face,” Everitt added.