A Novel Single-Composition Trichromatic White-Light Ca(3)Y(GaO)(3)(BO(3))(4):Ce(3+),Mn(2+),Tb(3+) Phosphor for UV-Light Emitting Diodes

Abstract

A novel single-composition white-emitting phosphor Ca(3)Y(GaO)(3)(BO(3))(4):Ce(3+), Mn(2+),Tb(3+) has been synthesized by a high-temperature solid-state reaction. The spectral overlap between the emission band of Ce(3+) and the excitation band of Mn(2+), which supports the occurrence of the energy transfer from Ce(3+) to Mn(2+), has been studied and demonstrated to be a resonant type via a dipole-quadrupole mechanism. Because there was no spectral overlap between the emission spectra of Ce(3+) and excitation band of Tb(3+) in our study, no energy transfer from Ce(3+) to Tb(3+) was observed, Indicating that Ce(3+) and Tb(3+) were coexcited. Through effective resonance-type energy transfer and coexcitation, the chromaticity coordinates of Ca(3)Y(GaO)(3)(BO(3))(4):Ce(3+),Mn(2+),Tb(3+) phosphors can be tuned from (0.152, 0.061) for Ca(3)Y-(GaO)(3)(BO(3))(4):Ce(3+) to (0.562, 0.408) for Ca(3)Y(GaO)(3)(BO(3))(4):Mn(2+), and eventually reaching (0.314, 0.573) for Ca(3)Y(GaO)(3)(BO(3))(4):Tb(3+). A white light-emitting diode (LED) was fabricated by using the white-emitting single-composition (Ca(0.97))(3)(Y(0.92))(GaO)(3)(BO(3))(4):0.01Ce(3+),-0.03Mn(2+),0.07Tb(3+) pumped by a 365 nm UV-chip. Our results indicated that the CIE chromaticity coordinates and correlated color temperature (CCT) for white UV-LEDs were (0.31, 0.33) and 6524 K, respectively. Therefore, our novel white Ca(3)Y(GaO)(3)(BO(3))(4):Ce(3+),Mn(2+),Tb(3+) can serve as a key material for phosphor-converted white-light UV-LEDs.