It is well known that LED (light0emitting diode) energy-saving lights have higher luminous efficiency and longer service life. The current LED lights are mainly used blue-ray LED chips as light sources, which hindered their popularity in the field of indoor lighting applications, since almost all residential lighting applications are warm white. Scientists from the University of Georgia, USA has recently developed the world’s first warm white LED lamp with single phosphor and single light-emitting unit in the world. Detailed information about this material has been published in the latest “Nature”.
As the paper’s lead author, Mr. Zhengwei Pan, associate professor at the University of Georgia, indicated that: currently, white-ray LED lamps are generally used as flashers and headlights (used in vehicles). But the emitted blue rays are less likeable, especially in indoor lighting applications. Our materials can successfully create a type of warm white light, and meanwhile achieve a realistic color reproduction. The previous improved LED lamp with single phosphor had failed to achieve such effect.
There are two main indicators to measure the quality of artificial light. Correlated color temperature is used to measure the well-being of the light. Take indoor lighting for example, color temperature lower than 4000K is an ideal correlated color temperature. Color reduction degree is another important indicator, naming the ability of the light source to simulate natural light. An ideal indoor lighting source should have a color reduction degree no less than 80. Distortion will occur when the color reduction degree below this value. The new developed materials meet these two conditions together: with correlated color temperature less than 4000K and color reduction degree higher than 85.
The general working principle of warm white LED lamp is coating phosphor with different colors on blue-ray LED chips to let them generate warm white rays. This is a type of phosphor-based white-ray LED lights. However, mixing these materials at a precise ratio needs a lot efforts and money. And the ultimate light color will have differences, since various materials has various responds to temperature changes.
Although the research result has huge market prospects, there are still remained several problems to be solved to have this type of material to be used in houses, schools and offices. The luminous efficiency of this new material is still much lower than white-ray LED light sources. In addition, the large-scale production will also face up with many challenges.