Two indicators to measure the quality of artificial light

PAN Zheng taste and his colleagues developed the material to meet these two conditions, correlated color temperature below 4000K and color reproduction of 85 controls. Pan said Zheng-wei,, jacket the blue led street light chip of the outer layer the different colors of, the phosphor of the warm white light, and then will be based on the of the white LED lights of the phosphor be able to be issued.

However, these materials according to the precise proportion of money and time and cost, the final color of the light will vary, because each raw material having the same response to temperature change. One of the authors, Li to Pan, Engineering University of Georgia PhD said: "using a single phosphor can solve the problems of instability, the light color of a single material, because as the temperature rises will not change."

In order to develop new phosphors, PAN Zheng-wei and his team select europium oxide, aluminum oxide, barium oxide and graphite, in which each one to take a small amount of mixed in together. They then powdered materials into a tube furnace heated to about 1450 degrees Celsius. The vacuum state of the gasification furnace so that the material deposited on the chassis, and the yellow light emitting compound, and then the inside of the bulb. Although the study results are encouraging, the Pan-Lin Zhengwei stressed that they need to solve several problems in lighting applications such material, for families, businesses and schools. The efficiency of the of new materials light-emitting far lower than the white filament led street lights of the pale blue. In addition, large-scale production will be challenged.