Luminescence properties, tunable emission and energy transfer of Na 3 Sc 2 (PO 4 ) 3: Sm 3+, Bi 3+phosphors

Na3Sc2(PO4)3:R (R = Bi3 +, Sm3 +, and Sm3 +/Bi3 +) are successfully synthesized in air atmosphere. The high-temperature solid-state reaction method is used in this work. The X-ray diffractometer patterns con-firm that all samples have the single pure phase Na3Sc2(PO4)3. Na3Sc2(PO4)3:Bi3 + displays blue emis-sion because of the Bi3 + -Sc 3 + metal-to-metal charge-transfer and the 3 P 1 & RARR;1S0 transition of Bi3 +. Na3Sc2(PO4)3:Sm3 + shows red-orange emission with four emission bands derived from the 4 G 5/2 & RARR;6H5/2 (550 -582 nm), 6 H 7/2 (582-625 nm), 6 H 9/2 (625-675 nm), and 6 H 11/2 (675-750 nm) transitions of Sm3 + . The optimal Sm3 + concentration in Na3Sc2(PO4)3:Sm3 + is -8mol%. An adjustable color emission from blue to red-orange of Na3Sc2(PO4)3:Sm3 +, Bi3 + with excitation at 345 nm can be observed when the ratio between Sm3 + and Bi3 + ions is changed. Na3Sc2(PO4)3:Sm3 +, Bi3 + emits red-orange light under excitation 406 nm. The optimal Bi3 + concentration in Na3Sc2(PO4)3:8mol%Sm3 +, Bi3 + is -6mol%. The energy trans-fer from Bi3 + to Sm3 + in Na3Sc2(PO4)3:Sm3 +, Bi3 + is verified by the spectral properties of samples. We discuss the influences of Bi3 + or Sm3 + concentration on luminescence properties of samples and analyze their luminous mechanism by energy level diagram. The experimental results of paper are useful for the research of new Bi3 + and Sm3 + doped phosphors. & COPY; 2023 Elsevier B.V. All rights reserved.