Research On Preparations And Properties Of CaAlSiN₃:Eu²⁺ Phosphors For White-Led

Ca1-xAlSiN3:xEu2+, Ca1-x.ySrxAlSiN3:yEu2+ and Sr1-xAlSiN3:xEu2+nitrides series phosphors were prepared by carbon hot reductive nitriding method. Studies various factors of the influencing sample structure and luminous property. For example, calcining temperature, rate of gas flow, holding time, flux agent, Eu2+ doping concentration and amount of graphite powder and so on. The results show that the sample possessed the optimum luminous performance under the condition of Ca1-xAlSiN3:xEu2+was 1650℃,6h, with gas flowing rate 5L/min, graphite powder doped amount was Ca2+ 1.5 times and NH4Cl 4wt%. The emission wavelength change with different x values, and the emission peak was at 550nm when the x value between 0.02 and 0.1; the emission peak was at 570nm when the x value between 0.1 and 0.17; the emission peak was at 640nm when the x value between 0.2 and 0.3. The excitation spectrum was a broad band spectrum between 350nm and 500nm. The concentration of Eu2+ effected the luminescence itensity greatly,20mol% was best.The optimum calcining condition of Ca1-x-ySrxAlSiN3:yEu2+ was 1650℃,6h, y=0.7, concentration of Eu2+ was 10% and NH4Cl 5wt%. The excitation spectrum is a broad band spectrum between 350nm and 600nm, and the emission peak was at 615nm nearly.The optimum calcining condition of Sr1-xAlSiN3:xEu2+ was 1650℃,6h, concentration of Eu2+ was 10% and NH4Cl 2wt%. The excitation spectrum is a broad band spectrum between 350nm and 600nm. The emission spectra were broad band spectra, peaking nearly 610nm. Finally, it adopts pure nitrides through high temperature solid-phase prepare Ca1-xAlSiN3: xEu2+, such party preparaed samples with emission wavelength than before do not have too big change, but obviously improve the intensity, in 1480℃insulation 6 hours, Ca3N2 excessive 0.02 mol, N2 flow 2L/min, H2 for flow is to 0.6 L/min, Eu2+ doping concentration 20% under the condition of the sample preparation income Ca0.8 AlSiN3:20mol% Eu2+ for optimum samples.These three phosphors have good development prospect, because of it was compensate for deficiency of red, and could better satisfy application requirements of white LED.