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

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 Ia (3) over bard (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 angstrom, R-c2 = 10.1 angstrom and R-c3 = 12.6 angstrom 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.