Red shifts, intensity enhancements and abnormally thermal quenching of Ba9Lu2Si6O24:Ce3+ emission by nitridation

Highlights: • Synthesis of Ba₉Lu₂Si₆O₂₄:Ce³⁺ and nitride Ba₉Lu₂Si₆O₂₄:Ce³⁺ phosphors. • Red shifts and intensity enhancements of Ce³⁺ emission by nitridation. • Abnormal emission increase with increased temperature for nitride Ba₉Lu₂Si₆O₂₄:Ce³⁺. -- Abstract: Ba₉Lu₂Si₆O₂₄:Ce³⁺ and nitrided Ba₉Lu₂Si₆O₂₄:Ce³⁺ phosphors were synthesized by a solid state reaction. To show the influence of introduced N³⁻ on Ba₉Lu₂Si₆O₂₄:Ce³⁺ phosphors, the crystal structure, phase and luminescent properties of the synthesized phosphors were investigated. And various techniques, such as X-ray diffraction and luminescence spectrometer, were used to investigate the synthesized Ba₉Lu₂Si₆O₂₄:Ce³⁺ and nitrided Ba₉Lu₂Si₆O₂₄:Ce³⁺ phosphors. The XRD patterns indicate that the synthesized phosphors have rhombohedral phase. Under the excitation at 400 nm, Ba₉Lu₂Si₆O₂₄:Ce³⁺ phosphors show the emission bands corresponding to the 5d → 4f transitions of Ce³⁺ ions. The substitution of N³⁻ to O²⁻ leads to the red shift and intensity enhancement of the Ce³⁺ emission. More importantly, the substitution of N³⁻ to O²⁻ results in an abnormal intensity increase with the increasing temperature.