First-principles study on secondary electron emission of MgO surface

The band gap and defect states of MgO thin films were investigated by using reflection electron energy loss spectroscopy (REELS) and high-energy resolution REELS (HR-REELS). HR-REELS with a primary electron energy of 0.3 keV revealed that the surface F center (FS) energy was located at approximately 4.2 eV above the valence band maximum (VBM) and the surface band gap width (E g S ) was approximately 6.3 eV. The bulk F center (F B ) energy was located approximately 4.9 eV above the VBM and the bulk band gap width was about 7.8 eV, when measured by REELS with 3 keV primary electrons. From a first-principles calculation, we confirmed that the 4.2 eV and 4.9 eV peaks were F S and F B , induced by oxygen vacancies. We also experimentally demonstrated that the HR-REELS peak height increases with increasing number of oxygen vacancies. Finally, we calculated the secondary electron emission yields (γ) for various noble gases. He and Ne were not influenced by the defect states owing to their higher ionization energies, but Ar, Kr, and Xe exhibited a stronger dependence on the defect states owing to their small ionization energies. C 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

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“…Details of the calculation can be found in Ref. 25. The computed γ values for the surface with oxygen vacancy are listed in Table II.…”

Section: Resultsmentioning

confidence: 99%

“…It has been reported that the peak at 4.2 eV may be owing to the surface F center on the MgO surface. 25 The peak at 6.3 eV is related to the surface inter-band transition. 19 The energy level of the surface F center, F S , is higher than that of the bulk F center, F B .…”

Section: Resultsmentioning

confidence: 99%

Band gap and defect states of MgO thin films investigated using reflection electron energy loss spectroscopy

et al. 2015

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“…As an example, attaching hydrogen atoms makes MgO͑111͒ surface insulating. 11 Alternatively, one can control the stoichiometry to neutralize the surface. For instance, the cubic-ZrO 2 ͑100͒ surface becomes insulating if one oxygen atom is removed from the O-terminated surface unit cell.…”

Section: B First-principles Implementationsmentioning

confidence: 99%

First-principles calculation of capacitance including interfacial effects

Lee

Han

et al. 2008

Journal of Applied Physics

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Articles you may be interested inTemperature effects in first-principles solid state calculations of the chemical shielding tensor made simple An efficient computational method is proposed within a first-principles framework to calculate capacitances of metal-insulator-metal structures including interfacial effects. In this approach, we employ metal-insulator models under external electric fields to calculate dielectric responses near the interface region. Macroscopically averaged potentials allow for evaluating the capacitance and local dielectric constants of the corresponding metal-insulator-metal capacitor. We apply this method to calculate the capacitance of Au/MgO͑100͒/Au and Ni/ ZrO 2 ͑110͒ / Ni with dielectric thicknesses of nanometers. While the Au/MgO interface is relatively free of interfacial effects, the computational results for Ni/ ZrO 2 indicate the presence of interfacial regions with dielectric constants noticeably lower than that of the bulk. Microscopic origins are discussed.

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“…A higher defect level appears to be advantageous for obtaining a larger SEE yield [10,11]. It was found that occupied defect states such as an oxygen vacancy (Fcenter) lying in the BG of MgO can cause an increase in the SEE yield [12]. The occupied defect state of the C-adsorbed MgO (100) surface could also contribute to an increase in the SEE yield in the case reported herein.…”

Section: Computational Setupmentioning

confidence: 81%

Effect of C and H contamination on the MgO surface properties studied using the first-principles method

Lee

2013

Journal of Information Display

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In the former experiment, the effect of aging temperature on the discharge characteristics of the magnesium oxide (MgO) film of the alternating-current plasma display panel was investigated from the point of view of surface contamination. It was found that C and H surface contamination can affect the surface properties, such as the surface conductivity and secondary electron emission (SEE) yield, of the MgO surface. For a better understanding of the effect of C and H contamination on the MgO surface properties, the electronic structures of C-and H-adsorbed MgO (100) surfaces were calculated through the first-principles method, using Cambridge Serial Total Energy Package. The occupied defect levels of the C-adsorbed MgO (100) surface, which lie in the mid-gap, play an important role in the potential emission mechanism of SEE. More C contamination at the MgO surface can induce more SEE and can thus reduce the firing voltage for discharge. The Fermi level of the H-adsorbed MgO (100) surface cuts the bottom edge of the conduction band, which means that the H-adsorbed MgO (100) surface reveals n-type conductivity. More H contamination at the MgO surface can reduce the wall charge accumulation ability and can thus increase the sustain voltage for discharge.

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First-principles study on secondary electron emission of MgO surface

Cited by 25 publications

References 27 publications

Band gap and defect states of MgO thin films investigated using reflection electron energy loss spectroscopy

Band gap and defect states of MgO thin films investigated using reflection electron energy loss spectroscopy

First-principles calculation of capacitance including interfacial effects

Effect of C and H contamination on the MgO surface properties studied using the first-principles method

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