Cu-doped quantum dots ( QDs) were used as color converting materials for preparing effi-cient white light-emitting diodes ( LEDs ) . The Cu-doped QDs synthesized by chemical method showed composition-tunable emission from green to deep red and large Stokes shifts. By using the combination of green light-emitting ZnInS:Cu QDs and red emitting ZnCdS:Cu QDs with blue GaN chips, a high color rendering white LED was fabricated. The resulting three-band RGB QD-white LED exhibits high performance with luminous efficacy of 71 lm/W, color rendering index up to 94, CIE-coordinates of (0. 352 4, 0. 365 1), and color temperature of 4 788 K. Based on the changes in the photoluminescence lifetimes of Cu-doped QDs, it is found that the energy transfer process from green ZnInS:Cu QDs to red ZnCdS:Cu QDs can be negligible, because the red QDs had no absorp-tion at green band. These results suggest that Cu-doped QDs are promising for solid state lighting.%利用胶体化学方法合成了发光波长可调的Cu掺杂量子点,其波长范围可从绿光到深红光连续调节.通过将绿光ZnInS:Cu和红光ZnCdS:Cu量子点与蓝光GaN芯片相结合,制备了高显色性的白光LED,其流明效率为71 lm·W-1,色温为4 788 K,显色指数高达94,CIE色坐标为(0. 352 4,0. 365 1). 通过测量Cu掺杂量子点的荧光衰减曲线,发现不存在从绿光ZnInS:Cu到红光ZnCdS:Cu量子点的能量传递过程,因为红光ZnCdS:Cu量子点在绿光波段没有吸收.实验结果表明,Cu掺杂量子点有望应用于固态照明领域.
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