采用高温固相法合成了Mn2+单掺杂及Mn2+, Ga3+共掺杂的γ-Zn3(PO4)2。γ-Zn3(PO4)2 :Mn2+的发射峰位于620 nm,而γ-Zn3(PO4)2:Mn2+, Ga3+发射光谱有两个发射峰,其中一个发射峰位于507 nm,另一个发射峰位于620 nm。507 nm的发射峰来自于处于四面体晶体场中Mn2+(CN=4)的4T1g-6A1g能级跃迁,而620 nm的发射峰来自于处于八面体晶体场中Mn2+(CN=6)的激发态4T1g-6A1g的能级跃迁。在Mn2+, Ga3+共掺杂的样品中,八面体场中Mn2+的激发光谱与四面体场中Mn2+的发射光谱有显著的光谱重叠,满足共振能量传递条件,从而发生了Mn2+(CN=4)向Mn2+(CN=6)的能量传递,对此进行了证明及讨论。此外,Mn2+离子在四面体场及八面体场中的浓度分布随着Ga3+离子的掺入量而发生变化。Ga3+离子对Mn2+在四面体场与八面体场浓度比值起到调节作用。随着Mn2+离子和Ga3+离子浓度的增加,发射光谱中绿光强度与红光强度比值也逐渐增加。最终,发射光谱中绿光强度与红光强度的相对比值是由Mn2+离子浓度、Ga3+离子浓度及Mn2+(CN=4)向Mn2+(CN=6)的能量传递3个因素决定的。
The Mn2 + and Ga3 + codopeγ-Zn3 ( PO4 ) 2 phosphors were synthesized by a high temperature sol id state reaction. The emission spectra of the phos phors showed a green band at 507 nm of Mn2+ due to tetrahedrally coordinated ( CN = 4) lattice, and a red band at 620 nm of Mn2+ in octahedral coordination (CN = 6). The spectral overlap between the emission band of Mn2+ due to tetrahedrally coordinated ( CN = 4) lattice and the excitation band of Mn2+ in octahe dral coordination (CN = 6), which supported the occurrence of the energy transfer from Mn2 + ( CN = 4) to Mn2+(CN = 6), was studied. The distribution of Mn2+ ions in tetrahedral and octahedral lattice changed with the incorporation of Ga3+ ions. Follow ing both Ga3 + and Mn/ + concentrations increasing, the ratio of the green to the red enhanced. The emis sion spectra were determined by the concentration of Mn2+ and Ga3+ and the energy transfer from Mn2+ (CN =4) to Mn2+ (CN =6).