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

Abstract KTb(CO3)2:Eu3+ phosphors with intense stokes emission were synthesized by hydrothermal method. Under the excitation of 368 nm light, the pure KTb(CO3)2 shows an intense green emission at 543 nm corresponding to the 5D4→7F5 transition of Tb3+, about 5 times higher than that of the K+-free Tb2O(CO3)2 phosphor. As the Tb3+ is partly substituted by Eu3+, the luminescence color can be transformed from green to red. The intensity of red emission of KTb(CO3)2:Eu3+ could greatly increase as the contents of Eu3+ without any concentration quenching. Under the excited by 368 nm near-ultraviolet, the quantum efficiencies of KTb(CO3)2 and KTb(CO3)2:0.3Eu3+ were 93% and 80%, respectively. The high quantum efficiency shows that KTb(CO3)2:Eu3+ is a useful color-tunable luminescence material under excitation of ultraviolet light in the anti-counterfeiting, lighting and display.