Synthesis and Photoluminescent Properties of Rare Earth Doped ZnO Hierarchical Microspheres
journal contributionposted on 13.03.2008, 00:00 by Xiaoyan Zeng, Junlin Yuan, Lide Zhang
Hierarchical ZnO microspheres constructed by mesoporous quasi-single-crystalline ZnO nanosheets were fabricated by pyrolysis of the microspheres of layered hydroxide zinc carbonate, Zn5(CO3)2(OH)6, which was the hydrothermal precipitate of zinc nitrate and urea. A growth mechanism of Zn5(CO3)2(OH)6 microspheres was proposed. During the pyrolysis process, single-crystalline Zn5(CO3)2(OH)6 nanosheets were transformed into mesoporous quasi-single-crystalline ZnO nanosheets. When the samples were doped with trivalent rare earth ion, RE3+ (RE = Pr, Sm, Tb, Ho, Tm), no ZnO → RE3+ energy transfer was observed. However, the ZnO:Eu3+ sample showed efficient Eu3+ emissions under UV photon excitation (λ < 365 nm), which is attributed to energy transfer from photon-generated electron−hole pairs to Eu3+ ions in the surface layer of the ZnO nanosheet.