Preparation and luminescent characteristics of white LED with LiCaPO_4:Eu~(3+) phosphor

A novel red emitting phosphor LiCaPO4:Eu3+ was synthesized by the high temperature solid state reaction method,and the effects of Eu3+ content,R+ and Cl-on the luminescent properties of the phosphor were investigated.LiCaPO4:Eu3+ phosphor presents several emission peaks under 399 nm excitation,which correspond to the 5D0→7FJ(J=0,1,2,3,4) transition of Eu3+,respectively,and the highest emission is located at 612 nm.At 612 nm emission,the excitation spectrum contains 200-350 nm and 350-450 nm two excitation bands,which correspond to a weak charge transition broad band absorption CTS and a strong f-f transition absorption of Eu3+,respectively,and the highest peak is located at 399 nm.The emission intensity of the phosphor is influenced by Eu3+ content,and reaches the maximum at 5% Eu3+.The concentration quenching mechanism is the d-d interaction by Dexter theory.Under the conditions of R+ or Cl-incorporated in the phosphor,the emission intensity can be enhanced,and it is found that Li+ and Cl-can exhibit the strongest charge compensation ability.