Study On Oxynitride Phosphor For White-LED

Sr_1-uBa_uSi₂O₂N₂:Eu²⁺ and Sr₃Al₂O_6-3u/2N_u:Eu²⁺ phosphors were prepared successfully by the high temperature solid state method. The effect of calcining temperature, gas flowing rate, calcining time and fluxing agent on the luminescence properties was studied systematically.The structure and luminescent properties of the sample were analyzed by XRD and fluorescence spectrophotometer. The results show that the optimum calcining condition of Sr_1-uBa_uSi₂O₂N₂:Eu²⁺ was 1350℃, 4h, with gas flowing rate 4L/min and NH₄Cl 0.04wt%. The emission spectra are broad band spectra, with the full width at half maximum of about 70nm. The emission peak changed with different u value between 0 and 0.75 , and the emission peak is at 494nm when the u value is 1. The excitation spectrum is a broad band spectrum between 350nm and 500nm. The concentration of Eu²⁺ would effect the luminescence itensity greatly, 15mol% was best. The optimum calcining condition of Sr₃Al₂O_6-3u/2N_u:Eu²⁺ was 1500℃, 3h, with NH₄Cl 0.2 wt%. The excitation spectrum is a broad band spectrum between 400nm and 580nm. The emission spectra were broad band spectra, peaking at 595nm, with the full width at half maximum of about 50nm. The dopant of Ce³⁺ would improve the luminescence intensity, and the optimum concentration of Ce³⁺ is 3 mol %, when the concentration of Eu²⁺ is 15mol %.