Bright and High-Color-Rendering White Light-Emitting Diode Using Color-Tunable Oxychloride and Oxyfluoride Phosphors
Bright and High-Color-Rendering White Light-Emitting Diode Using Color-Tunable Oxychloride and Oxyfluoride Phosphors
复制标题
DOI：
10.1021/acs.jpcc.6b03177
复制
发表时间：
2016-07
影响因子：
3.7
通讯作者：
P. Dai;Jianshu Cao;Xintong Zhang;Yichun Liu
中科院分区：
文献类型：
--
作者：
P. Dai;Jianshu Cao;Xintong Zhang;Yichun Liu
由三基色荧光粉和近紫外光发光二极管转换而成的白光照明在普通照明中显示出巨大的潜力。然而，这种方法的一个主要问题是由于三基色荧光粉之间的重吸收而产生的白色照明的发光效率较低。在这项工作中，我们提出了一种通用而有效的方法，通过使用具有相同主体的双色荧光粉来实现高效的白色发光二极管(WLED)，该双色荧光粉可以通过重吸收来降低能量损失。采用阳离子取代法合成了色调可调的Sr7.95Si4O12Cl8：0.05Eu2+(SSO_Cl：0.05Eu2+)荧光粉，并通过对→进行Mg/Ca取代，实现了发光颜色由蓝绿到蓝/黄的调谐。红移发射是由于钙离子尺寸变小导致Eu~(2+)d轨道分裂增加所致，而Eu~(2+)蓝移发射在Mg~(2+)取代Sr~(2+)中是不常见的。用这两种器件制作了发光效率(ηL)为28.9-56lm/W，CRI值为79-90.2的WLED.
White lighting converted by tricolor phosphor and near-ultraviolet light-emitting diode demonstrates great potential in general lighting. However, a major problem with this approach is the lower luminous efficiency of the resulting white lighting by the reabsorption among tricolor phosphors. In this work, we propose a general but effective method for achieving high-efficacy white light-emitting diodes (WLEDs) by using two-color phosphors having the same host that can lower energy loss by reabsorption. Color-tunable Sr7.95Si4O12Cl8:0.05Eu2+ (SSO_Cl:0.05Eu2+) phosphors are synthesized by cationic substitution strategy, and the emission colors can be tuned from blue-greenish to blue/yellow by Sr → Mg/Ca substitution. The red-shifted emission is attributed to the increased Eu2+ d-orbital splitting owing to the smaller size of Ca2+, whereas blue-shifted Eu2+ emission is unusual in Mg-substitution for Sr2+. WLEDs with luminous efficacies (ηL) of 28.9–56 lm/W and CRIs of 79–90.2 are demonstrated using the two-co...