New LED produces wide spectrum of light over longer periods

Dr. Yue Kuo, the Dow Chemical Professor in the Artie McFerrin Department of Chemical Engineering at Texas A&M University, has fabricated a new type of LED capable of producing a wide spectrum light while operating for long periods of time at atmospheric conditions.

Thomas Edison invented the first incandescent light bulb 130 years ago, which greatly contributed to the advancement of civilization. However, that technology is antiquated, economically inefficient to operate and fragile. Fluorescent lights are energy efficient but they are bulky and have to “warm-up” when turned on. Their bulbs contain phosphorus and mercury, which are toxic to the environment.

Today’s LED lights are also energy friendly but are expensive and difficult to manufacture. The process to make conventional LEDs is very complicated, as it involves the growth of single crystal layers on the single crystal substrate. Each layer has to contain low defects for it to work. The cost of LED lights is usually 10 times the cost of the incandescent bulb, because the equipment to produce them is expensive, the raw materials are expensive, and the environmental and safety issues are critical. Another disadvantage of the current LEDs is they do not produce white light from a single chip. This requires extra manipulation, such as using a set of three chips emitting different lights or adding a phosphorus material to the blue or UV chip to produce the white light.

More at College of Engineering.