Template-assemble synthesis of ZnO:Er nanostructure and their upconversion luminescence properties

ZnO:Er3+ crystallites with controllable morphology of nanorod, columnlike, swordlike, flower-, and prismlike were prepared via the cetyltrimethylammonium bromide (CTAB) assisted hydrothermal process. The effect of the reaction conditions on the morphologies was investigated. A higher concentration of CTAB and/or temperature favor formation of ZnO:Er3+ with larger aspect ratio. When LiOH was used to obtain Zn(OH)4(2-) instead of NaOH, the nanoparticles with smaller aspect ratio was formed due to the different rate determining step. Different solvent also introduced the formation of nanoparticles with different shape as a result of interface-solvent interaction. The different upconversion photoluminescence was observed in different morphology samples under infrared 980 nm excitation, which is causes the variation of the Er3+ local structure.