Symmetry dependent evolution of the Tb3+ photoluminescence in Ba6(RE1−xTbx)9B79O138 (RE = La and Y, 0 ≤ x ≤ 1) and Ce3+-to-Tb3+ sensitization effect: A re-visit to REBaB9O16

摘要: Abstract Extensive studies on photoluminescence (PL) were devoted to the well-known “ RE BaB 9 O 16 ” family, while structure remained unsolved until recent work determination of its new analogue Ba 6 Bi B 79 138 . Accordingly, a re-visit with formula was rationally performed by syntheses and Tb 3+ -PL study La ( BLBO ) Y BYBO ). Powder XRD patterns 1− x  = La Y, 0 ≤   ≤ 1) show linear shrinkage or expansion unit cell in : , respectively. The ratio cyan/green (C/G) emission proposed evaluate evolution principle -site symmetry both series phosphors. C/G value remains unchanged it is sensitive -to-Y substitution For example, keeps almost constant (∼0.30) when 0.10 ≤   ≤ 0.5; dramatic increase (from 0.33 0.67) occurs range 0.50 ≤   ≤ 0.90, accompanied transition from centrosymmetric noncentrosymmetric; thereafter. Ce -to-Tb sensitization effect applied 0.3− y 0.7  ≤ 0.3), samples  = 0.2 possess strongest green emission.