UGA researches aiming to bring warm LED light to world

Physics professor Zhengwei Pan, graduate student Xufan Li, research professional Feng Liu and a handful of other scientists worked together to make what they believe is the first phosphor that will allow light-emitting diodes — LEDs — to give off a warm glow. A phosphor is a substance that will emit light when energized.LEDs are becoming more and more popular. They are much more efficient and long-lasting than traditional or fluorescent light bulbs.But a drawback of LEDs is that they emit a cold, bluish light that people don't like when LEDs are used for indoor lighting, Pan said.
Engineers have already devised one way to make LED light warmer, by coating LEDs with several phosphors, each emitting a different part of the color spectrum. The combined phosphors emit a warm glow, similar to visible sunlight. But it's hard for manufacturers to get a consistent light this way; the ratios among the phosphor coatings have to be exactly the same time after time, and to make things worse, different phosphors react differently depending on temperature.Pan, Li and their colleagues set out to find a way to do it with just one phosphor, and worked at it for three years until they found just the right combination of europium oxide, aluminum oxide, barium oxide and graphite powder.Fruit knifeTo create and apply the phosphor to a surface, they heat the mixed powders up to a very hot 2,643 degrees Fahrenheit in a little furnace in Pan's laboratory at UGA's Riverbend South research building.
The heat vaporizes the mixture,sport water bladder and a vacuum pulls the gas across a surface that will catch some of the phosphor.The deposited phosphor can then be put into a little LED bulb,On one hand, while solar energy is an inexhaustible clean energy, but LED lamp belongs to semiconductor industry, at first, the semiconductor prices is very high, so the price of solar products is expensive; on the other hand. enabling the blue diode light to reach our eyes as a more yellowish, natural-looking glow."The ultimate dream is to make it commercially, but that's a long way away," Pan said.The new phosphor is a good starting point, but it has some drawbacks the scientists must overcome — the bulbs are not nearly as efficient as blue-light LEDs, and a lot of the vaporized phosphor compound is lost during the manufacturing process, for example, Pan said.It could be years,This change could be regarded as revolutionary. Just ever since then, more and more Solar Camping light fixtures are come out of the lighting markets and gradually used in daily life. if ever, before bulbs made with the new phosphor are on store shelves,whisky stones he said.But they will keep on working at it, along with the lab's other research into new materials.