Single-Phased White-Light Phosphors Ca(9)Gd(PO(4))(7):Eu(2+),Mn(2+) under Near-Ultraviolet Excitation

Abstract

Single-phased white-light-emitting phosphors Ca(9)Gd(PO(4))(7):Eu(2+),Mn(2+) were synthesized by solid state reactions. Tuning the Eu(2+)/Mn(2+) ratio via the energy transfer varied the emission hue of Ca(9)Gd(PO(4))(7):0.007Eu(2+),xMn(2+) from blue-greenish (0.219, 0.371) to white-light (0.326, 0.328) and eventually to red (0.625, 0.307). The mechanism of transferring energy from a sensitizer Eu(2+) to an activator Mn(2+) in Ca(9)Gd(PO(4))(7):Eu(2+),Mn(2+) phosphors was demonstrated to be an electric dipole-quadrupole interaction. Combining a near-UV 380 nnn chip and a white-emitting Ca(9)Gd(PO(4))(7):0.007Eu(2+),0.02Mn(2+) phosphor produced a white-light near-UV LED, demonstrating CIE chromaticity coordinates of (0.312, 0.327) and a color temperature of 6569 K.