Cross Relaxation of Sm~(3+) and Energy Transfer Between Sm~(3+) and Eu~(3+) Ions in (Ca_(0.97)Sr_(0.03))_3(VO_4)_2 Phosphor Host

摘要

An attempt was made to verify that the inhibition of Sm~(3+) → Eu~(3+) energy transfer in (Ca_(0.97)Sr_(0.03))_(2.82)(VO_4)_2:Sm~(3+) ,0.12Eu~(3+) phosphors at Sm~(3+) content levels of ＞0.06 mol can be ascribed to the cross-relaxation effect. The emission peak at around 951 nm attributed to the ~6F_(11/2)→~6H_(5/2) transition of Sm~(3+) , which should be barely detectable according to the energy-gap law, was observed in this work by exciting the ~4K_(11/2) state of Sm~(3+) . The results indicate that cross-relaxation channels, which can depopulate the ~4F_(3/2) state of Sm~(3+) , such as 1st Sm~(3+) (~4F_(3/2)) + 2nd Sm~(3+) (~6H_(5/2))→1st Sm~(3+) (~6F_(11/2)) + 2nd Sm~(3+) (~6F_(5/2)) and 1st Sm~(3+) (~4F_(3/2)) + 2nd Sm~(3+) (~6H_(5/2))→1st Sm~(3+) (~6F_(5/2)) + 2nd Sm~(3+) (~6F_(11/2)), may form and become efficient at an Sm~(3+) doping level of ≧0.06 mol. It was found that the 951-nm emission suffered from concentration quenching, which resulted from a dipole-dipole multipolar interaction.