A novel red-emitting phosphor Mg(2)Y(2)Al(2)Si(2)O(12):Ce(3+)/Mn(2+) for blue chip-based white LEDs

Traditional white light-emitting diodes (LEDs) (blue chip + YAG:Ce(3+) yellow phosphor) have the limitation of red deficiency, which limits their application in the illumination field. The single cation/anion substitution or co-doping of activators can increase the red component; however, the large energy loss is attributed to the ultra-long Stokes shift and energy transfer. This work attempts to utilize the short-distance Stokes shift and a small amount of energy transfer to increase the red component in two steps. First, based on a large number of previous research results, the Mg(2)Y(2)Al(2)Si(2)O(12):Ce(3+) phosphor is selected. Second, additional enhancement of the red component in the emission spectrum was achieved by ion co-doping Mn(2+) into Mg(2)Y(2)Al(2)Si(2)O(12):Ce(3+). The emission peaks for samples Mg(2)Y(2)Al(2)Si(2)O(12):Ce(3+),Mn(2+) shift from 600 to 635 nm with increase in the concentration of Mn(2+), and the emission spectra intensity of Mg(1.97)Y(1.93)Al(2)Si(2)O(12):0.07 Ce(3+),0.03 Mn(2+) anomalously increased by ∼37%, which was attributed to the increase in the distance between Ce(3+) ions because of the doping of Mn(2+) ions, and reduction in the concentration of defects in the crystal, resulting in the energy loss decreases of Ce(3+). The emission peak of Mg(1.97)Y(1.93)Al(2)Si(2)O(12):0.07 Ce(3+),0.03 Mn(2+) shifts to 618 nm and the quantum efficiency was as high as 83.07%. Furthermore, this sample has high thermal stability and the emission intensity was still 80.14% at 120 °C. As such, it has great potential in the application of white LEDs.