Department of Research and Development, Koito Manufacturing Co., Ltd, Shizuoka 424-8764, Japan.
Nat Commun. 2012;3:1132. doi: 10.1038/ncomms2138.
The luminous efficiency of white light-emitting diodes, which are used as light sources for next-generation illumination, is continuously improving. Presently available white light-emitting diodes emit with extremely high luminance because their emission areas are much smaller than those of conventional light sources. Consequently, white light-emitting diodes produce a glare that is uncomfortable to the human eye. Here we report a yellow-emitting phosphor, the Eu(2+)-doped chlorometasilicate (Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2), which can be used to create glareless white light-emitting diodes. The (Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2) exhibits a large Stokes shift, efficiently converting violet excitation light to yellow luminescence, and phosphors based on this host material have much less blue absorption than other phosphors. We used crystal structure analysis to determine the origin of the desired luminescence, and we used (Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2) and a blue-emitting phosphor in combination with a violet chip to fabricate glareless white light-emitting diodes that have large emission areas and are suitable for general illumination.
用于下一代照明的白光发光二极管的发光效率在不断提高。目前的白光发光二极管的发射区域比传统光源小得多，因此具有极高的亮度，发出的光使人眼感到不适。在这里，我们报告了一种黄色荧光粉，即 Eu(2+)掺杂的氯硅酸盐(Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2)，它可用于制造无眩光的白光发光二极管。(Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2)具有较大的斯托克斯位移，可有效地将紫光激发光转换为黄色发光，并且基于该主体材料的荧光粉比其他荧光粉具有更少的蓝色吸收。我们使用晶体结构分析确定了所需发光的起源，并使用(Ca(1-x-y,)Sr(x,)Eu(y))(7)(SiO(3))(6)Cl(2)和蓝色发射荧光粉与紫光芯片相结合，制造出具有大发射区域且适用于一般照明的无眩光白光发光二极管。
