Control of the photoluminescence in Ba0.97Y2Si3O10:Eu2+ phosphors via the intensification effect of the second luminescence centre

Abstract

Cation substitution has been proven to be a prevailing strategy for efficiently tuning the luminescence properties of divalent europium (Eu²⁺). In this work, the isostructural Ba_0.97Y_2−xLu_xSi₃O₁₀:0.03Eu²⁺ (BYSO:Eu,xLu) and Ba_0.97Y_2−yGd_ySi₃O₁₀:0.03Eu²⁺ (BYSO:Eu,yGd) (x/y = 0.00–2.00) solid solutions with two emission bands were designed based on the existence of a second potential luminescence center in the Ba_0.97Y₂Si₃O₁₀:0.03Eu²⁺via the conventional solid-state reaction. Combined with the variation of distortion and disorder, a new model named the intensification effect of the second luminescence center was built in view of the local and average structures. All the samples exhibit a series of asymmetric and broad-band emissions covering the blue and cyan or blue and green regions, due to the increased Eu²⁺ amounts in the second coordination zone, which is attributed to the increase in distortion and disorder by varying the Gd³⁺ or Lu³⁺ content. Moreover, the thermal properties of BYSO:Eu,yGd are superior to the commercial BaMgAl₁₀O₁₇:Eu²⁺, with T_1/2 over 523 K and small reductions in emission intensity at 423 K. The present research aims to shed new light on the improvement of phosphor properties with broad-band emission and high luminous efficacy.