High efficiently color-tunable emission in KTb(CO3)2:Eu3+ phosphors

KTb(CO 3 ) 2 :Eu 3+ phosphors with intense stokes emission were synthesized by hydrothermal method . Under the excitation of 368 nm light, the pure KTb(CO 3 ) 2 shows an intense green emission at 543 nm corresponding to the 5 D 4 → 7 F 5 transition of Tb 3+ , about 5 times higher than that of the K + -free Tb 2 O(CO 3 ) 2 phosphor. As the Tb 3+ is partly substituted by Eu 3+ , the luminescence color can be transformed from green to red. The intensity of red emission of KTb(CO 3 ) 2 :Eu 3+ could greatly increase as the contents of Eu 3+ without any concentration quenching. Under the excited by 368 nm near-ultraviolet, the quantum efficiencies of KTb(CO 3 ) 2 and KTb(CO 3 ) 2 :0.3Eu 3+ were 93% and 80%, respectively. The high quantum efficiency shows that KTb(CO 3 ) 2 :Eu 3+ is a useful color-tunable luminescence material under excitation of ultraviolet light in the anti-counterfeiting, lighting and display.