Improvement orange-red emitting by codoping A+ (A=Li, Na, K) in Ca2BO3Cl:Sm3+phosphor

Sm3+ doped Ca2BO3Cl with different charge compensation approaches are synthesized by a high temperature solid state reaction method, and systematically characterized by the luminescent properties and the CIE chromaticity coordinates. All the samples show the characteristics orange-red emission of Sm3+ ion with good CIE chromaticity coordinates. When codoped Li+, Na+, K+ as charge compensators, the relative emission intensities of Ca2BO3Cl:Sm3+ are increased to 1.57, 1.99 and 1.78 times that of the direct charge balance. The difference is considered to be due to the different ion radii effect on the crystal field of Sm3+ ions. The results indicate that Na+ ion may be the optimal compensation charge for Ca2BO3Cl:Sm3+.