A Novel Single-Composition Trichromatic White-Light Ca₃Y(GaO)₃(BO₃)₄:Ce³⁺,Mn²⁺,Tb³⁺ Phosphor for UV-Light Emitting Diodes

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.