A new diphosphate Ba2LiGa(P2O7)2: synthesis, crystal structure and Eu3+-activated fluorescence performance

Abstract

Finding new luminescent materials is always a meaningful goal in the field of photoelectricity studies. Herein, a new diphosphate compound Ba₂LiGa(P₂O₇)₂ (BLGP) was prepared using a high-temperature flux method. It displays an anionic chain structure of [LiGa(P₂O₇)₂]_∞, constructed from P₂O₇, LiO₅ and GaO₆ polyhedra. The Ba²⁺ ions are distributed in the voids between the [LiGa(P₂O₇)₂]_∞ chains, bonding them and maintaining charge balance. To test its potential as a luminescent host, Eu³⁺ doped phosphors BLGP:xEu³⁺ (x = 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) were synthesized and studied in detail. Upon 394 nm light irradiation, BLGP:xEu³⁺ showed bright orange emission with a dominant peak at 595 nm due to the ⁵D₀ → ⁷F₁ transition of Eu³⁺. The optimal doping amount of Eu³⁺ is 0.20, and the internal quantum efficiency of the phosphor B_1.8LGP:0.2Eu³⁺ was determined to be 67%. The temperature quenching behavior of B_1.8LGP:0.2Eu³⁺ was studied, suggesting that the photoluminescence (PL) intensity decreased to about 50% at 450 K due to thermal quenching. All these features show that this compound is a good luminescent host material for Eu³⁺ activators.