Yibo Han

Publications (11) View all

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  Available from: Yibo Han

  Article: Crystal-Field Splitting of the Bright Eu 3+ Ions in YPO 4 Micro-crystals Detected by Zeeman Splitting in Pulsed High Magnetic Fields

  Y Han, G Du, J Han, · X Kan, · L Li
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  ABSTRACT: The crystal-field splitting levels in YPO 4 Eu 3+ micro-crystals are inves-tigated by the Zeeman splitting in photoluminescence spectrum. X-ray diffraction pattern and microscopic images indicate small tetragonal nano-particles attaching on the surfaces of the mainly hexagonal micro-crystals. The peaks correspond to the transitions from 5 D 0 excited state to 7 F 1 and 7 F 2 ground states are split in pulsed high magnetic fields, crystal-field splitting levels associated with different magnetic moments are clarified, which are completely different from that was supposed by the X-ray, microscopy, and zero-field photoluminescence results.
  Journal of Low Temperature Physics 09/2012; · 1.19 Impact Factor
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  Article: Band gap shift and the optical nonlinear absorption of sputtered ZnO-TiO2 films.

  Yi-Bo Han, Jun-Bo Han, Zhong-Hua Hao
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  ABSTRACT: ZnO-TiO2 composite films with different Zn/Ti atomic ratios were prepared with radio frequency reactive sputtering method. The Zn percentage composition (f(Zn)) dependent optical band gap and optical nonlinear absorption were investigated using the transmittance spectrum and the Z-scan technique, respectively. The results showed that composite films with f(Zn) in the range of 23.5%-88.3% are poor crystallized and their optical properties are anomalous which exhibit adjustable optical band gap and large optical nonlinear absorption. The optical absorption edge shifted to the blue wavelength direction with the increasing of f(Zn) and reached the minimum value of 285 nm for the sample with f(Zn) = 70.5%, which has the largest direct band gap of 4.30 eV. Further increasing of f(Zn) resulted in the red-shift of the optical absorption edge. The maximum optical nonlinear absorption coefficient of 1.5 x 10(3) cm/GW was also obtained for the same sample with f(Zn) = 70.5%, which is more than 40 times larger than those of pure TiO2 and ZnO films.
  Journal of Nanoscience and Nanotechnology 06/2011; 11(6):5024-7. · 1.56 Impact Factor
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  Article: Linear and nonlinear optical properties of ZnO nanorod arrays

  Si Xiao, Xiongrui Su, Chun Li, YiBo Han, GuoJia Fang, Ququan Wang
  Chinese Physics B. 01/2008; 17:1291.
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  Article: Highly efficient avalanche multiphoton luminescence from coupled Au nanowires in the visible region.

  Qu-Quan Wang, Jun-Bo Han, Dong-Lai Guo, Si Xiao, Yi-Bo Han, Hong-Mei Gong, Xian-Wu Zou
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  ABSTRACT: We demonstrate highly efficient avalanche multiphoton luminescence (MPL) from ordered-arrayed gold nanowires (NWs) with low time-average excitation intensity, Iexc (5.0-9.1 kW/cm2). The intensity of avalanche MPL, IMPL, is about 10(4) times larger than that of three-photon luminescence, the slope partial differential log IMPL/ partial differential log Iexc of avalanche MPL reaches as high as 18.3, and the corresponding polarization dependence of IMPL has a form of cos50 phip. The emission dynamics of avalanche MPL and three-photon luminescence are also studied comparatively. These observations indicate that the highly efficient avalanche MPL is attributed to the giant enhancement and coupling of longitudinal surface plasmon resonance of ordered-arrayed gold NWs.
  Nano Letters 04/2007; 7(3):723-8. · 13.20 Impact Factor
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  Article: Imaging spatial distributions of laser-induced charge and spin in GaAs/AlGaAs two-dimensional electron gas by pump-probe second harmonic generation

  Yibo Han, Si Xiao, Hongming Zhao, Hanchao Gao, Guiguang Xiong, Ququan Wang
  Applied Physics letters. 01/2007; 91:202114.