Three-step fine-tuning by doping Bi³⁺, Tb³⁺ and Eu³⁺/Sm³⁺ in Gd₂MoB₂O₉ host for accurate white emission

Tuning for accurate white light emission in single-composition phosphor is challenging due to the presence of complex energy transfer. Herein we report the synthesis and characterization of single-composition white light emission phosphors with accurate color coordinates, which were tuned through a three-step doping strategy. Under the excitation of 280 ​nm UV light, Gd_1.474MoB₂O₉: 0.30Bi³⁺, 0.20Tb³⁺, 0.026Eu³⁺ and Gd_1.46MoB₂O₉: 0.30Bi³⁺, 0.19Tb³⁺, 0.05Sm³⁺ exhibit white light emission with color coordinates of (0.339, 0.335) and (0.332, 0.346), very close to standard white light. The emission intensity at 100 ​°C maintains 82.07% and 91.35% of that of room temperature, demonstrating good thermal stability. The Gd_1.474MoB₂O₉: 0.30Bi³⁺, 0.20Tb³⁺, 0.026Eu³⁺ and Gd_1.46MoB₂O₉: 0.30Bi³⁺, 0.19Tb³⁺, 0.05Sm³⁺ white phosphors have the advantages of convenient synthesis conditions, stable chemical properties and emission very close to standard white light. This three-step doping strategy can be used for designing Bi³⁺ based single-composition white emission phosphors.