Single phase white LED phosphor Ca3YAl3B4O15:Ce3+,Tb3+,Sm3+ with superior performance: Color-tunable and energy transfer study

Abstract

The white light-emitting diodes, contributing as a light initiator for the succeeding generation, is now becoming a consistently developing and attractive research area. However, the weak thermal stability, high correlated color temperature (CCT), and low color rendering (Ra) restrict its effectiveness for large-scale implementation. In this work, we reported for the first time the incorporation of rare-earth ions Ce3+-Tb3+-Sm3+ into Ca3YAl3B4O15 (CYAB) in the fabrication of WLEDs, which showed tunable photoluminescence properties to accomplish exceptional thermal stability, single-phase white light emission, and efficient energy transfer among Ce3+, Tb3+, Sm3+ ions, respectively. The crystal structure and the rare earth ion dopants in the cation borate CYAB phosphors were quantitatively evaluated, that highlighting the preferences at 9-fold-coordinated Y sites. The sensitization effects were studied by evaluating the photoluminescence, lifetime curves, and quantum efficiencies, respectively. Besides this, the CY0.45AB:0.50Tb3+,0.05Sm3+ and CY0.65AB:0.03Ce3+,0.20Tb3+,0.12Sm3+ phosphors possess significant resistance towards thermal quenching phenomena. The white LED either containing CY0.45AB:0.50Tb3+,0.05Sm3+ phosphor blended with the commercial blue phosphor or the single-phase WLED only containing CY0.65AB:0.03Ce3+,0.20Tb3+,0.12Sm3+ phosphor exhibited warm white emissions either with low CCT ≈ 4543 K or 3913 K and high Ra with 86.0 or 84.4, respectively. These results are superior to the commercial WLED containing Y3Al5O12:Ce3+ phosphor and blue LED chip (CCT ≈ 7746 K, Ra ≈ 75), that furnish either as a good candidate for the fabrication of warm WLED.