TY - JOUR
T1 - Luminescent properties in relation to controllable phase and morphology of LuBO 3:Eu 3+ nano/microcrystals synthesized by hydrothermal approach
AU - Li, Yanping
AU - Zhang, Jiahua
AU - Zhang, Xia
AU - Luo, Yongshi
AU - Lu, Shaozhe
AU - Ren, Xinguang
AU - Wang, Xiaojun
AU - Sun, Lingdong
AU - Yan, Chunhua
PY - 2009/2/10
Y1 - 2009/2/10
N2 - The calcite and vaterite type LuBO 3:Eu 3+ nano/microcrystals with various morphologies were synthesized by the hydrothermal (HT) approach through controlling the pH values of the precursor solutions. The calcite type LuBO 3:Eu 3+ shows the dominant magnetic dipole 5D 0- 7F 1 emission due to S 6inversion symmetry of Lu. It also shows a symmetrical O-Eu charge transfer (CT) excitation band, which, however, is asymmetrical and broad in the material prepared by the solid-state (SS) reaction method. The effect of the residual OH - groups introduced in HT synthesis is discussed on O-Lu exciton annihilation and local environment distortion. Two different Eu 3+ centers, one of which is with inversion symmetry, are observed in vaterite type LuBO 3:Eu 3+. The HT sample with nanostructures, such as vaterite type flowerlike LuBO 3:Eu 3+, demonstrates a red shift of the CT band and appearance of a long excitation tail at the long wavelength side of the CT band. XRD, selective excitation and fluorescence decay measurements indicate that the red shift is induced by an increase of crystal lattice parameters, and the excitation tail is responsible to the Eu 3+ ions located at lower symmetric sites. These sites are attributed to the positions at or close to the surface of the nanostructures in the sample. As the lower symmetric sites are selectively excited, the red emission of 5D 0- 7F 2 of Eu 3+ enhanced twice relatively to the orange emission of 5D 0- 7F 1, exhibiting superior color chromaticity in red for display application. The luminescence properties of interior Eu 3+ and outside Eu 3+ are studied and discussed in detail.
AB - The calcite and vaterite type LuBO 3:Eu 3+ nano/microcrystals with various morphologies were synthesized by the hydrothermal (HT) approach through controlling the pH values of the precursor solutions. The calcite type LuBO 3:Eu 3+ shows the dominant magnetic dipole 5D 0- 7F 1 emission due to S 6inversion symmetry of Lu. It also shows a symmetrical O-Eu charge transfer (CT) excitation band, which, however, is asymmetrical and broad in the material prepared by the solid-state (SS) reaction method. The effect of the residual OH - groups introduced in HT synthesis is discussed on O-Lu exciton annihilation and local environment distortion. Two different Eu 3+ centers, one of which is with inversion symmetry, are observed in vaterite type LuBO 3:Eu 3+. The HT sample with nanostructures, such as vaterite type flowerlike LuBO 3:Eu 3+, demonstrates a red shift of the CT band and appearance of a long excitation tail at the long wavelength side of the CT band. XRD, selective excitation and fluorescence decay measurements indicate that the red shift is induced by an increase of crystal lattice parameters, and the excitation tail is responsible to the Eu 3+ ions located at lower symmetric sites. These sites are attributed to the positions at or close to the surface of the nanostructures in the sample. As the lower symmetric sites are selectively excited, the red emission of 5D 0- 7F 2 of Eu 3+ enhanced twice relatively to the orange emission of 5D 0- 7F 1, exhibiting superior color chromaticity in red for display application. The luminescence properties of interior Eu 3+ and outside Eu 3+ are studied and discussed in detail.
UR - http://www.scopus.com/inward/record.url?scp=61849185595&partnerID=8YFLogxK
U2 - 10.1021/cm802015u
DO - 10.1021/cm802015u
M3 - Article
AN - SCOPUS:61849185595
SN - 0897-4756
VL - 21
SP - 468
EP - 475
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 3
ER -