K3YB6O12:Ce3+,Tb3+: A near-ultraviolet-excitable emission-tunable phosphor for white light-emitting diodes

A series of near-ultraviolet-excitable emission-tunable phosphors K3YB6O12:Ce3+,Tb3+ have been successfully prepared via a conventional high-temperature solid-state reaction technique. Their phase structures and luminescence properties were investigated. The green emission of Tb3+ can be largely sensitized by Ce3+ in K(3)YB(6)O(12 )host due to efficient Ce3+-> Tb3+ energy transfer process, which leads to broad and strong excitation band in near-ultraviolet region for K3YB6O12:Ce3+,Tb3+ phosphors. The critical distance, efficiency, and mechanism of Ce3+-> Tb3+ energy transfer are also calculated and determined in term of theoretical formulas. Upon excitation with near-ultraviolet (similar to 365 nm), the tunable emission-color from blue to green can be realized in the as-prepared phosphors. These results indicate that the K3YB6O12:Ce3+,Tb3+ phosphors might have potential application in near-ultraviolet pumped white light-emitting diodes.