Tartrate-assisted hydrothermal synthesis of (Ce1-Tb )F3 nanocrystals for better luminescence

Abstract Tartrate (Tar2−, Tar2−/(Ce3++Tb3+) molar ratio up to 10) was originally examined as a chelate additive for the synthesis of hexagonal-structured (Ce1-xTbx)F3 nanocrystals (x = 0–0.4) via hydrothermal reaction at 150 °C for 24 h. Characterization of the products by XRD, FE-SEM, TEM and optical spectroscopies showed that (1) phase pure products can be obtained up to a Tar2−/(Ce3++Tb3+) molar ratio of ~6.0 and a Tb3+ content (x value) ~0.3, (2) the optimal amount of Tb3+ for Tb3+ emission is x ~ 0.1, (3) Tar2− tends to preferentially adsorb on (002) basal plane to yield larger plate-like nanocrystals that show better luminescence, (4) Ce3+ → Tb3+ energy transfer exists in the Tb3+ doped nanocrystals, and the efficiency of energy transfer was analyzed to be ~54.1% at x = 0.10 through lifetime analysis of the 339 nm Ce3+ emission, and (5) the lifetime of the ~544 nm green emission of Tb3+ was found to steadily decrease from ~9.17 to 4.09 ms with increasing x from 0.05 to 0.30.