Toward temperature-dependent Bi³⁺-related tunable emission in the YVO₄ : Bi³⁺ phosphor

Up until now, many previous works have indicated us that the photoluminescence (PL) properties of phosphors sometimes can be changed with the change in the external temperature, resulting in the anomalous PL phenomena and correlated new applications that are difficult to achieve at room temperature. In this work, we report the temperature-dependent Bi³⁺-related PL properties in the YVO₄:Bi³⁺ phosphor. Our findings show that increasing the temperature from 10 to 300 K enables manipulating the energy interaction from (Formula presented.) groups to Bi³⁺, thereby leading to the temperature-induced color tuning from blue (0.183, 0.212) to yellow (0.418, 0.490). Upon this heating process, we further reveal that the dynamic Bi³⁺ luminescence has experienced a regular transition from double-exponential to single-exponential decay, which results in the decrease in the average Bi³⁺ lifetime from 122.606 to 0.376 μs. Discussions on the PL results imply that the tunable PL observations are due to the interplay of temperature-dependent energy transfer from (Formula presented.) groups to Bi³⁺ and redistribution of the excited ³P₀ and ³P₁ states of Bi³⁺ upon the thermal stimulation. This work not only presents the temperature-triggered Bi³⁺ tunable properties in the well-studied YVO₄ host lattice but also can provide new insights into revealing Bi³⁺-related PL mechanism in other Bi³⁺-doped photonic materials in the future and, in the meanwhile, gives some directive ideas for us to explore previously unnoticed applications for rare-earth (RE; eg, Eu³⁺, Pr³⁺, Tb³⁺, Eu²⁺, Er³⁺, etc) and other non-RE (eg, Bi³⁺, Mn⁴⁺, Mn²⁺, Cr³⁺, etc) doped phosphors.