Structure, luminescence property and abnormal energy transfer behavior of color-adjustable Ca3Hf2SiAl2O12:Ce3+,Mn2+ phosphors

Abstract

A series of color-adjustable phosphors Ca₃Hf₂SiAl₂O₁₂:Ce³⁺,Mn²⁺ were synthesized through a high temperature solid-state method. Ca₃Hf₂SiAl₂O₁₂ belongs to body-centered cubic crystal system and Iad (230) space-group. It was found that three different cation sites in the Ca₃Hf₂SiAl₂O₁₂ phase were occupied evenly by Ce³⁺ and Mn²⁺ ions. Different situations of Mn²⁺ occupying sites and energy transfer from Ce³⁺ to Mn²⁺ can appear with different Mn²⁺ content and the critical distance was calculated to be R_c1 = 10.8 Å, R_c2 = 10.1 Å and R_c3 = 12.6 Å after calculation of energy transfer from the Ce³⁺ to Mn²⁺ by using the concentration quenching method. Ca₃Hf₂SiAl₂O₁₂:Ce³⁺,Mn²⁺ phosphors exhibited a broad excitation band ranging from 300 to 450 nm and two broad asymmetric emission bands upon 400 nm excitation. The emission colors of Ca₃Hf₂SiAl₂O₁₂:Ce³⁺,Mn²⁺ could be tuned from blue-green (0.2303, 0.3265) to white (0.3350, 0.3388) by changing the ratio of Ce³⁺/Mn²⁺. The correlated color temperature can be adjusted from 12 763 K to 5379 K. It indicated that Ca₃Hf₂SiAl₂O₁₂:Ce³⁺,Mn²⁺ possesses potential applications in white-LEDs.