Development of near-ultraviolet-excitable single-phase white-light-emitting phosphor KBaY(BO3)2:Ce3+,Dy3+ for phosphor-converted white light-emitting-diodes

The development of near-ultraviolet (n-UV)-excitable single-phase white-light-emitting phosphor is highly meaningful for phosphor-converted white light-emitting-diodes (pc-WLEDs) based on n-UV chips. In this work, a series of Dy3+ singly doped and Ce3+, Dy3+ co-doped KBaY(BO3)2 phosphors with different doping concentration of Ce3+/Dy3+ were designed and synthesized via a solid state reaction at high temperature, and their phase structure, photoluminescence properties and potential application in WLEDs were investigated in detail. The prominent sensitization effect of Ce3+ on Dy3+-luminescence based on Ce3+→Dy3+ energy transfer is authenticated by comparatively investigating the photoluminescence excitation and emission spectra of the as-prepared phosphors. The critical distance, efficiency, and mechanism of Ce3+→Dy3+ energy transfer are calculated and determined in term of the theoretical formulas. The n-UV-excitable white light emission is realized in the KBaY(BO3)2:Ce3+,Dy3+ phosphors with the appropriate doping concentration of Ce3+ and Dy3+ ions. A pc-WLEDs device is successfully fabricated by the combination of the single-phase KBaY(BO3)2:Ce3+,Dy3+ phosphor and an n-UV (~365 nm) LED chip. All these properties indicate that the developed single-phase KBaY(BO3)2:Ce3+,Dy3+ phosphor may have potential application prospect for pc-WLEDs.