Photoluminescence properties of green-emitting YBO₃:Ce ³⁺, Tb³⁺ phosphor for near UV excitation

YBO₃:Ce³⁺,Tb³⁺ phosphor was prepared from rare earth oxides and boric acid by a solid state reaction. The phosphor absorbs near UV light through 4f-5d transitions of Ce³⁺, followed by broad emissions through 5d-4f transitions of Ce³⁺ and sharp emissions through 4f-4f transitions of Tb³⁺. Spectroscopic investigations for samples with various Ce³⁺ and Tb³⁺ concentrations reveal nonradiative energy transfer from Ce³⁺ to Tb³⁺. Emission color of the YBO₃:Ce³⁺,Tb³⁺ varies from blue (0.163, 0.019) to green (0.321, 0.585) depending on the Ce³⁺ and Tb³⁺ concentrations. The optimized green-emitting Y _0.82Ce_0.03Tb_0.15BO₃ phosphor has an emission color of (0.309, 0.547) with an external quantum efficiency of 76.7%. The photoluminescence intensity of this phosphor at 150°C keeps 87% of its intensity at room temperature, showing sufficient thermal stability for white light emitting diode applications.