Effect of substitution of nitrogen ions to red-emitting Sr_3B_2O_(6-3/2x)N_x:Eu~(2+) oxy-nitride phosphor for the application to white LED

摘要

The luminescence properties of orange-red-emitting Eu~(2+) activated Sr_3B_2O_(6-3/2x)N_x were optimized for application to blueear UV light-emitting diodes (LEDs). Sr_3B_2O_(6-3/2x)N_x:Eu~(2+) phosphor showed broad orange-red emission peaking at 600-650 nm under blue and n-UV excitations of 450 and 360 nm, respectively; the emission peak of phosphor was affected by nitrogen ion substitution. Boron nitride raw materials affect luminescence properties of phosphor; a small amount of BN reacts as a flux for synthesis of Sr_3B_2O_6 and a large amount of BN helps Sr_3B_2O_(6-3/2x)N_x:Eu~(2+) phosphor to have longer-wavelength emission peak. A 447 nm-emitting blue LED-pumped white LED with a mixture of Sr_3B_2O_(6-3/2x)N_x:Eu~(2+) (x=1) and Ba_2SiO_4:Eu~(2+) green-emitting phosphor was fabricated; it is observed that it showed color coordinates of (0.3648, 0.3605) and CRI value of 96.