通过在YAG∶Ce3+ 和YAG∶Ce3+, Pr3+ 荧光粉体系中分别掺入Cr3+ 离子来提高蓝光管芯白光LED的显色指数。Cr3+ 离子的加入，增加了红光发射，这归因于Cr3+的2E-4A2跃迁的零声子线和声子边带发光。Ce3+→Cr3+的能量传递是增强红光发射的重要方式，在YAG∶Ce3+，Cr3+ 体系中，由发射光谱得到的Cr3+ 的红光与Ce3+ 黄光发射强度的比值(I2/I1)与通过寿命测量得到的强度比很好符合。YAG∶Ce3+, Pr3+，Cr3+ 体系中，在只有Ce3+ 离子被激发的状态下(λex=340 nm)， 3种能量传递过程同时存在: Ce3+→Pr3+、Ce3+→Cr3+ 和Pr3+→Cr3+，进一步增加了红光比例。利用这两种荧光粉和460 nm蓝光发射管芯封装得到的白光LED，在正向驱动电流为20 mA时，LED的显色指数分别为80.4和81.4。Y₃Al₅O₁₂∶Ce³⁺,Cr³⁺ Phosphors

Triply doped Y3Al5O12∶Ce3+, Pr3+, Cr3+ phosphors with Ce3+ and Pr3+ substituting for Y3+ sites and Cr3+ substituting for Al3+ site are prepared by solid state reaction. A broad emission spectrum composed a yellow emission band from Ce3+, a light red emission line from Pr3+ and a deep red emission line from Cr3+, which are generated through energy transfer among the dopant ions. The study of photoluminescence and fluorescence decay indicates that there exist energy transfers from Ce3+→Cr3+ and Ce3+→Pr3+→Cr3+. The effect of energy transfer on relative intensities of the three emissions is analyzed. A white LED is fabricated using a blue LED chip coated with the triply doped phosphor and shows a color rendering index of 81.4 and 80.4, respectively.It is higher than that either using Ce3+ and Cr3+ doubly doped phosphor or Ce3+ singly doped phosphors.