TY - JOUR
T1 - Photoluminescence of perovskite nanosheets prepared by exfoliation of layered oxides, K2Ln2Ti3O10, KLnNb2O7, and RbLnTa2O7 (Ln: lanthanide ion)
AU - Ida, Shintaro
AU - Ogata, Chikako
AU - Eguchi, Miharu
AU - Youngblood, W. Justin
AU - Mallouk, Thomas E.
AU - Matsumoto, Yasumichi
PY - 2008/6/4
Y1 - 2008/6/4
N2 - Luminescent perovskite nanosheets were prepared by exfoliation of single- or double- layered perovskite oxides, K2Ln2Ti 3O10, KLnNb2O7, and RbLnTa 2O7 (Ln: lanthanide ion). The thickness of the individual nanosheets corresponded to those of the perovskite block in the parent layered compounds. Intense red and green emissions were observed in aqueous solutions with Gd1.4Eu0.6Ti3O10- and La 0.7Tb0.3Ta2O7-nanosheets, respectively, under UV illumination with energies greater than the corresponding host oxide band gap. The coincidence of the excitation spectrum and the band gap absorbance indicates that the visible emission results from energy transfer within the nanosheet. The red emission intensity of the Gd1.4Eu 0.6Ti3O10-nanosheets was much stronger than that of the La0.90Eu0.05Nb2O 7-nanosheets reported previously. The strong emission intensity is a result of a two-step energy transfer cascade within the nanosheet from the Ti-O network to Gd3+ and then to Eu3+. The emission intensities of the Gd1.4Eu0.6Ti3O10-and La 0.7Tb0.3Ta2O7-nanosheets can be modulated by applying a magnetic field (1.3-1.4 T), which brings about a change in orientation of the nanosheets in solution. The emission intensities increased when the excitation light and the magnetic field directions were perpendicular to each other, and they decreased when the excitation and magnetic field were collinear and mutually perpendicular to the direction of detection of the emitted light.
AB - Luminescent perovskite nanosheets were prepared by exfoliation of single- or double- layered perovskite oxides, K2Ln2Ti 3O10, KLnNb2O7, and RbLnTa 2O7 (Ln: lanthanide ion). The thickness of the individual nanosheets corresponded to those of the perovskite block in the parent layered compounds. Intense red and green emissions were observed in aqueous solutions with Gd1.4Eu0.6Ti3O10- and La 0.7Tb0.3Ta2O7-nanosheets, respectively, under UV illumination with energies greater than the corresponding host oxide band gap. The coincidence of the excitation spectrum and the band gap absorbance indicates that the visible emission results from energy transfer within the nanosheet. The red emission intensity of the Gd1.4Eu 0.6Ti3O10-nanosheets was much stronger than that of the La0.90Eu0.05Nb2O 7-nanosheets reported previously. The strong emission intensity is a result of a two-step energy transfer cascade within the nanosheet from the Ti-O network to Gd3+ and then to Eu3+. The emission intensities of the Gd1.4Eu0.6Ti3O10-and La 0.7Tb0.3Ta2O7-nanosheets can be modulated by applying a magnetic field (1.3-1.4 T), which brings about a change in orientation of the nanosheets in solution. The emission intensities increased when the excitation light and the magnetic field directions were perpendicular to each other, and they decreased when the excitation and magnetic field were collinear and mutually perpendicular to the direction of detection of the emitted light.
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U2 - 10.1021/ja7114772
DO - 10.1021/ja7114772
M3 - Article
C2 - 18461931
AN - SCOPUS:44449135570
SN - 0002-7863
VL - 130
SP - 7052
EP - 7059
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 22
ER -