• Transactions on Electrical and Electronic Materials
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• 제12권5호
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• pp.200-203
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• 2011

In this research, nitrogen (N)-doped zinc oxide (ZnO) thin films have been grown on a sapphire substrate by dielectric barrier discharge (DBD) in pulsed laser deposition (PLD). DBD has been used as an effective way for massive in-situ generation of N-plasma under conventional PLD process conditions. Low-temperature photoluminescence spectra of N-doped ZnO thin films provided near-band-edge emission after a thermal annealing process. The emission peak was resolved by Gaussian fitting and showed a dominant acceptor-bound excitation peak ($A^{\circ}X$) that indicated acceptor doping of ZnO with N. The acceptor binding energy of the N acceptor was estimated to be approximately 145 MeV based on the results of temperature-dependent photoluminescence (PL) measurements.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1363-1370
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• 2007

The geometrical structures of pyridazin-3-one derivatives (4,5-dihalopyridazin-3-one and 4-halo-5- alkoxypyridazin-3-one) with various functional and substituent groups were fully optimized using the ab initio Hartree-Fock (HF) and second order Moller-Plesset perturbation (MP2) methods. At the N2-, C4-, and C5- positions on the pyridazin-3-one rings, the structural and electronic features pertaining to the variations of the functional and substituent groups were analyzed, respectively. The trends in the variation of the bond lengths, atomic charges, and energetics (relative energy, binding energy) of the derivatives induced by changing the electron donating functional groups (X1 = OMe, OEt) to electron withdrawing groups (X1 = Cl, NO2) were examined. The variations of the bond lengths, atomic charges, and binding energies with the electron withdrawing strength of the substituent groups (Y = Me → F) were also investigated.

• Mass Spectrometry Letters
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• 제2권2호
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• pp.49-52
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• 2011

Competitive binding of $C_{60}$ and $C_{70}$ to meso-substituted porphyrins was studied by mass spectrometry (MS). Electrospray ionization MS was employed to acquire the mass spectra of 1 : 1 porphyrin-fullerene complexes formed in a mixture of mesosubstituted porphyrin and fullerite to determine the ratio of complexes between $C_{60}$ and $C_{70}$. Matrix-free laser desorption ionization MS was used to obtain the mass spectra of fullerite to measure the mole fraction of $C_{60}$ and $C_{70}$. The binding constant ratio ($K_{70}$/$K_{60}$) was determined from the mass spectral data. The difference in standard Gibbs free energy change, ${\Delta}({\Delta}G^o)_{70-60}$, for the competitive binding of $C_{60}$ and $C_{70}$ was calculated from $K_{70}$/$K_{60}$. Of the five porphyrins, tetraphenyl, tetra(4-pyridyl), tetra(4-carboxyphenyl), tetra(3,5-di-tert-butylphenyl), and tetra(pentafluorophenyl) porphyrins, the first three non-bulky porphyrins yield negative values of ${\Delta}({\Delta}G^o)_{70-60}$, whereas the other two bulky porphyrins result in positive values of ${\Delta}({\Delta}G^o)_{70-60}$. This result indicates that $C_{70}$ binding to porphyrin is thermodynamically favored over $C_{60}$ binding in non-bulky porphyrins, but disfavored in bulky ones. It also suggests that the binding mode of $C_{70}$is different between non-bulky and bulky porphyrins, which is in line with previous experimental findings of the "side-on" binding to non-bulky porphyrins and the $C_{60}$-like "end-on" binding to bulky porphyrins.

• 한국세라믹학회지
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• 제31권6호
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• pp.587-594
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• 1994

(Ba, Sr)TiO3-based PTCR ceramics were sintered and cooled down with various cooling conditions in the air. AES was applied to investigate the composition change in the grain boundary and bulk area of oxidatively cooled samples. Ba component was deficit in grain boundary region, while oxygen was abundant than bulk region. The discrete changes of oxygen binding energies were confirmed in the grain boundary region of the heavily oxidized samples. It was supposed that the large binding energy shift resulted from the oxidation of the segregated Mn in grain boundary region and this idea was supported by the DV-X$\alpha$ molecular energy simulation.

• 센서학회지
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• 제14권6호
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• pp.369-373
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• 2005

High quality CdTe single crystal for the solar cell fabrication was grown by vertical Bridgman method. The etch pits patterns of (111) surfaces of CdTe etched by Nakagawa solution was observed the (111)A compesed of Cd atoms with typical triangle etch pits of pyramid mode. From the photoluminescence measurement on (111)A, we observed free exciton ($E_{x}$) existing only high quality crystal and neutal acceptor bound exciton ($A^{0}$,X) having very strong peak intensity. Then, the full width at half maximum and binding energy of neutral acceptor bound exciton were 7 meV and 5.9 meV, respectively. By Haynes rule, an activation enery of impurity was 59 meV. Therefore, the origins on impurity level acting as a neutral acceptor were associated Ag or Cu elements.

• Carbon letters
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• 제8권4호
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• pp.292-298
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• 2007

In order to investigate functional groups on the surface of Multi-walled Carbon Nanotubes (MWCNTs) induced by oxyfluorination, XPS (X-ray photoelectron spectroscopy) analysis was carried out. All core level spectra of MWCNTs were deconvoluted to several Pseudo-Voigt functions (sum of Gaussian-Lorentzian functions). Both O1s and F1s binding energy of oxyfluorinated MWCNTs shifted high value as increment of fluorine mixing ratio. The carbon-fluorine covalent bonding concentration increased as increment of fluorine mixing ratio. The shape and intensity of OF10-MWCNTs are similar with those of as-received MWCNTs. However, the intensity and binding energies of main peak position of OF20-MWCNTs and OF30-MWCNTs were dramatically increased by oxyfluorination.

• Nuclear Engineering and Technology
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• 제34권3호
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• pp.202-210
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• 2002

The details of the electronic structure of the perfect crystal provides a critically important foundation for understanding the various defect states in uranium dioxide. In order to understand the local defect and impurity mechanism, the calculation of electronic structure of UO$_2$ in the one-electron approximation was carried out, using a semi-empirical tight-binding formalism(LCAO) with and without f-orbitals. The energy band, local and total density of states for both spin states are calculated from the spectral representation of Green’s function. The bonding mechanism in Perfect lattice of UO$_2$ is discussed based upon the calculations of band structure, local and total density of states.

• Food Science and Biotechnology
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• 제17권5호
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• pp.919-924
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• 2008

The aim of this study was to observe the changes in allergenicity of saeujeot (salted and fermented shrimp) using a competitive indirect enzyme-linked immunosorbent assay (Ci-ELISA). The fermentation conditions tested for saeujeot consisted of various temperatures (25, 15, and $5^{\circ}C$) and salt concentrations (25, 15, and 10%). When saeujeot was fermented at a low salt concentration and high temperature, the binding ability of mAb and shrimp-allergic patient serum to allergen was significantly decreased. In particular, the binding ability of mAb to allergen in saeujeot fermented with 10% salt at $25^{\circ}C$ for 5 days decreased to 5%. Also, the binding ability of shrimp-allergic patient serum to allergen in saeujeot fermented for 5 days with 10% salt at $25^{\circ}C$ was 8%. In conclusion, the binding of mAb and shrimp-allergic patient serum to tropomyosin in saeujeot decreased with longer fermentation periods, lower salt concentrations (10%), and higher temperatures ($25^{\circ}C$).

• 대한화학회지
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• 제53권3호
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• pp.272-278
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• 2009

$Ca^+-(CO)_n$,과 $Ca^+-(CO_2)_n$ (n=1,2) complex에 대한 구조와 결합 에너지를 MP2/6-311++G(2d,p) 방 법과 B3LYP/6-311++G(2d,p) 방법에 의해 계산하였고 vibrational frequencies도 계산하였다. $Ca^+-(CO)_n$의 경우 C-bonded complex와 O-bonded complex가 다 가능함을 보였고, $Ca^+-(CO)_2$에서는 선형과 $C_{2v}$ 형태가 나타남을 볼 수 있었으며 더 안정한 형태는 $C_{2v}$ 구조로 밝혀졌다. $Ca^+-(CO_2)_2$에서도 선형과 $C_{2v}$ 형태를 볼 수 있는데 이 경우는 선형이 근소한 에너지 차이로 더 안정한 것으로 나타났다.

• 반도체디스플레이기술학회지
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• 제23권1호
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• pp.92-96
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• 2024

The application of the technology for forming Al₂O₃ thin films using ALD(atomic layer deposition) method is rapidly increasing in the semiconductor and display fields. In order to increase the efficiency of the ALD process in a mass production line, metallic by-products generated from the ALD process chamber must be effectively collected. By collecting by-products flowing out of the chamber with a cold trap device before they go to the vacuum pump, damage to the vacuum pump can be prevented and the work room can be maintained stably, resulting in increased process flow rate. In this study, a cold trap was installed between the ALD process chamber and the dry pump to measure and analyze by-products generated during the Al₂O₃ thin film deposition process. As a result, it was confirmed that Al and O elements were discharged, and the collection forms were two types: bulk and powder. And the binding energy peaked at 73.7 ~ 74.3 eV, the binding energy of Al 2p, and 530.7 eV, the binding energy of O 1s, indicating that the binding structure was Al-O.