Multifunctional near-infrared Zn2TiO4:Cr3+ phosphors for luminescence, thermometry, and plant cultivation

A novel near-infrared phosphors Zn2TiO4:Cr3+ were synthesized through solid-state reaction, and the phosphors exhibit near-infrared emission at 600-850 nm under the excitation of 467 nm. An emission peak appears at 716 nm, which is attributed to 2E→4A2 spin-forbidden transition of Cr3+. Phase purity, photoluminescence properties and crystal filed environment of Zn2TiO4:Cr3+ were systematically investigated. Both the concentration and thermal quenching mechanisms were analyzed in detail. Moreover, the emission band of the phosphor match with characteristic absorption of PFR. At 398 K, the relative sensitivity Sr and absolute sensitivity Sa were estimated. The findings of this study demonstrated that the phosphors Zn2TiO4:Cr3+ are promising for both optical thermometry and plant cultivation.