Rare earth phosphate core/shell nanostructures were synthesized via facile ultrasound irradiation method.XRD and TEM were em-ployed to characterize the structure and morphology properties.The photoluminescence(PL) properties of TbPO4/CePO4 and CePO4/TbPO4 core/shell nanorods were studied to explore the energy transfers from Ce3+ to Tb3+.In the Ce0.9Tb0.1PO4/LaPO4 core/shell nanorods,the PL intensity of Ce0.9Tb0.1PO4 nanorods was enhanced when the LaPO4 shells were coated.
Bright Cu-doped ternary ZnCdS quantum dots （ZnCdS：Cu QDs） with varied Cd concentrations were synthesized in aqueous solution by using a convenient microwave method.These ternary QDs could be directly dispersed in water solution.By regulating the Cd2＋ concentration from 0 to 50% （mole fraction of the cations）,the photoluminescence excitation （PLE） peak of such ZnCdS：Cu QDs could be continuously redshifted from 320 nm to 380 nm,while their photoluminescence （PL） peak was redshifted from 490 nm to 580 nm,exhibiting multicolor Cu-related emissions.Furthermore,the quantum yield of the ZnCdS：Cu QDs could reach as high as 12% by regulating the Cu doping concentration.These ZnCdS：Cu ternary QDs with kind surface conditions and good composition-controllable optical properties may have potential application in many areas such as sensing,bioimaging,and light-emitting diodes.
A novel strategy is proposed to directly synthesize water-soluble hexagonal NaYF4 nanorods by doping rare-earth ions with large ionic radius (such as La^(3+), Ce^(3+), Pr^(3+), Nd^(3+), Sm^(3+), Eu^(3+), and Gd^(3+)), and the dopant- controlled growth mechanism is studied. Based on the doping effect, we fabricated water-soluble hexagonal NaYF4:(Yb,Er)/La and NaYF4:(Yb,Er)/Ce nanorods, which exhibited much brighter upconversion fluorescence than the corresponding cubic forms. The sizes of the nanorods can be adjusted over a broad range by changing the dopant concentration and reaction time. Furthermore, we successfully demonstrated a novel depth-sensitive multicolor bioimaging for in vivo use by employing the as-synthesized NaYF4:(Yb,Er)/La nanorods as probes.
Xuefeng YuMin LiMengyin XieLiangdong ChenYan LiQuquan Wang
