Structural, tunable emission and energy transfer of Ca9In(PO4)7:Ce3+,Tb3+/Dy3+ phosphors

In this paper, we have synthesized a series of ultraviolet-emitting Ca 9 In(PO 4 ) 7 :Ce 3+ ,Tb 3+ and Ca 9 In(PO 4 ) 7 :Ce 3+ ,Dy 3+ phosphors. The Ca 9 In(PO 4 ) 7 :Ce 3+ phosphor exhibits bright blue emission under UV excitation. The Tb 3+ /Dy 3+ single doped Ca 9 In(PO 4 ) 7 can exhibit weak green and yellow emission, respectively. Based on the efficient energy transfer from Ce 3+ to Tb 3+ /Dy 3+ , the luminous efficiency of Tb 3+ /Dy 3+ in Ca 9 In(PO 4 ) 7 :Ce 3+ ,Tb 3+ and Ca 9 In(PO 4 ) 7 :Ce 3+ ,Dy 3+ can be remarkably promoted. The effects of Ce 3+ /Tb 3+ /Dy 3+ concentration, decay curves, PL emission and excitation spectra on the energy transfer from Ce 3+ to Tb 3+ /Dy 3+ in Ca 9 In(PO 4 ) 7 were investigated. The experimental results demonstrated that the energy transfer efficiency could reach 21.77 and 30.3% in Ca 9 In(PO 4 ) 7 :Ce 3+ ,Tb 3+ and Ca 9 In(PO 4 ) 7 :Ce 3+ ,Dy 3+ , respectively. This study suggests that the synthesized Ca 9 In(PO 4 ) 7 :Ce 3+ ,Tb 3+ and Ca 9 In(PO 4 ) 7 :Ce 3+ ,Dy 3+ compounds have potentials to be used as white light-emitting phosphors in UV light-emitting diodes.