A single-component white-light-emitting fluorescent material with high color rendering index based on resonance energy transfer

Abstract

The development of single-component high-quality warm white light-emitting phosphors is a research hotspot and key in the field of white light illumination. In this paper, a series of Ca₈ZnGa_0.4La_0.6(PO₄)₇:xEu²⁺,yMn²⁺ solid solutions were prepared based on resonance energy transfer to achieve a controlled tuning of the emission color from blue-green to red, and a single-phase white-light-emitting phosphor Ca₈ZnGa_0.4La_0.6(PO₄)₇:0.003Eu²⁺,0.02Mn²⁺ was obtained. The doping of Mn²⁺ leads to the rearrangement of Eu²⁺ at different cation positions, while the sensitization effect of different emission peaks of Eu²⁺ on Mn²⁺ was inconsistent, and the contribution of the 490 nm emission peak was greater. In addition, the thermal stability properties of the different emission peaks of Eu²⁺ differed due to different thermal ionization probabilities, and the Mn²⁺ emission centers showed better thermal stability properties as the non-radiative relaxation between Eu²⁺ and Mn²⁺ was enhanced with increasing temperature. Finally, the Ca₈ZnGa_0.4La_0.6(PO₄)₇:0.003Eu²⁺,0.02Mn²⁺ phosphor-converted WLED exhibited a high quality warm white light emission with an ultra-high color rendering index (R_a = 94.7) and a suitable CCT value (4277 K) at an operating current of 300 mA.