LUMINESCENT PROPERTIES OF Sr3B2O6: Eu2+ YELLOW-EMITTING PHOSPHOR FOR WHITE LIGHT-EMITTING DIODES

Eu2+doped Sr3B2O6 yellow phosphor for warm white LED was synthesized by high temperature solid-state method. The structure and optical properties of Sr3B2O6:Eu2+ were studied. Results indicate that Sr3B2O6:Eu2+ has a rhombohedral crystalline structure. The excitation spectrum of phosphor is a wide-band spectrum mainly peaking at 469 nm, which is suitable for GaN-based blue light LED excitation. The luminescent spectrum of phosphor exhibits a broad emission band centered at 566 nm, corresponding to the typical 4f65d1–4f7 transition of Eu2+. Guass fitting shows the main emission peak is at 575 nm, which is identical with the dominant wavelength of the yellow phosphor. The CIE chromaticity coordinate of white LED is (x = 0.389, y = 0.419). The LED reveals warm tone and the relevant color temperature of that is 4044 K. The luminescent efficiency of White LED reaches 18l m/W, which is higher than reported.