Unusual Tm3+ sensitization-induced white-emitting and thermostable improvement in Ba2Y2Ge4O13:Dy3+ phosphor for solid-state lighting and optical thermometry

Currently, the development of single-phase white emitters is an interesting research topic. Researchers have paid much attention to tune white-emitting of Dy³⁺-activated phosphors via Tm³⁺ sensitization strategy. However, the role of Tm³⁺ sensitization on luminescence thermostability was usually underestimated. Herein, color-tunable germanate phosphors Ba₂Y₂Ge₄O₁₃ (BYGO):Tm³⁺,Dy³⁺ were prepared. The white light emission is achieved due to the effective energy transfer from Tm³⁺ to Dy³⁺. A BYGO:Tm³⁺,Dy³⁺-based w-LED exhibits warm white-emitting. Moreover, the back-energy transfer of Dy³⁺→Tm³⁺ contributes to the improvement of luminescence thermal stability. Meanwhile, the difference of temperature-dependent Tm³⁺ and Dy³⁺ emissions realizes satisfactory temperature sensing properties. This work provides a deep understanding for the role of Tm³⁺ sensitization strategy on color tuning and thermostable improvement, promoting multifunctional utilizations of Dy³⁺-activated phosphors.