MgO protecting layers, which have high ion induced secondary electron emission coefficient (), are required in order to decrease the firing voltage of plasma displays. Theoretical estimation of ideal value is needed for a design of better protecting layers. In this study, we report our developed calculation method based on a tight-binding quantum calculation and application to an estimation of values of MgO protecting layers. From our calculation results, it was revealed that electron trap sites arising from surface roughness would work as an effective emission sites and increase value. Especially for Xe þ species as induced ion, the value changed drastically by the presence of the trapped electron. It is also suggested that a presence of chemisorbed water on the MgO surface decreases the values because of the contribution of the electrons at the low energy levels originated from surface OH groups. #

For the analysis of the relationship between carrier transfer properties and morphologies of light-emitting polymers, it is important to investigate carrier transfer pathways. We developed a novel computational method for analysis of carrier transfer pathways by the combination of tight-binding quantum chemistry calculation with Monte Carlo method. This novel method was applied to the prediction of electron transfer in poly(9,9'-dioctylfluorene)(PDOF), which is known as a blue light-emitting polymer. We successfully investigated the electron transfer pathways in PDOF films. We found that the electron transfer mainly occurs in an intra chain, but the inter chain electron transfer was also observed between aromatic rings whose distance was less than 4.0 Å.

Initial deposition processes of Mg on MgO were studied using our novel quantum chemical molecular dynamics (QCMD) simulator. This novel simulator was developed on the basis of our tight-binding quantum chemical molecular dynamics (TB-QCMD) simulator and our molecular dynamics simulator. The justification of the novel QCMD simulator was shown by the excellent agreement of the QCMD result with the first-principles results and experimental results for the physicochemical properties of the MgO crystal. Dynamic behaviors of Mg atom deposited on the MgO( 001) and ( 111) surfaces were simulated by the novel QCMD method. It was shown that the mobility of Mg deposited on the MgO(001) surface was larger than that on the (111) surface, which suggests the difference between the interaction of the deposited Mg atom with the MgO(111) surface and that with the MgO(001) surface.

Abstract— The relationship between crystal structures and emission properties has been computationally investigated for Eu2+‐doped phosphors. The electronic structure of the Eu2+‐doped BaMgAl10O17 phosphor was analyzed by using the quantum chemistry method. The different effects of O and Ba atoms on the Eu 5d states were determined. The presence of O and Ba atoms increases and decreases the energy level of the Eu 5d orbital by forming anti‐bonding and bonding interactions, respectively. According to the electronic‐structure analysis, the structure index that represents the local geometrical information of the Eu atom was defined. The relationship between the crystal structures and the emission wavelengths of the 1 6 Eu2+‐doped oxide phosphors were studied by using the quantitative structure‐property relationship (QSPR). The QSPR model suggested that the both O and alkaline‐earth atoms around the Eu atom are of importance in the determination of the emission wavelength. The interaction between the Eu and the nearest O atoms make the Eu2+ emission wavelength short. On the other hand, the interaction from the alkaline‐earth atoms around the Eu atom lengthens the Eu2+emission wavelength. This evaluation method is useful in selecting the host material that indicates a desirable emission wavelength of the Eu2+‐doped phosphors.

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