Shunichiro Nobuki
Hitachi
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Featured researches published by Shunichiro Nobuki.
Journal of Applied Physics | 2009
Shirun Ho; Shunichiro Nobuki; Norihiro Uemura; Tatsuya Miyake; Kenkichi Suzuki; Yoshiro Mikami; Masatoshi Shiiki; Shoichi Kubo
A generalized analytical method to determine the density of energy states of electron emission source (EES) is devised by using a thermal excitation and emission model for an exoelectron in the MgO layer and the emission time constants of the exoelectron extracted from experimental stochastic distributions of discharge delay time. When applied to Si-doped MgO, the emission time constant of the exoelectron from the Si EES becomes shorter at high temperature and at short time intervals due to thermal excitation. The density of energy states of the Si EES DSi(E) shows the main peak at 736 meV, a satellite peak at 601 meV, and broad energy structures over the range of 586–896 meV. The effective number of Si EES is 5.5 times larger than that in purified MgO. The excitation energy in a Si-doped MgO cluster with a crystal structure is obtained to be 0.83 eV by using the symmetry-adapted-cluster configuration interaction method and the Si EES contributes to exoelectron emission. The thermal excitation is governed...
Journal of The Society for Information Display | 2009
Shirun Ho; Shunichiro Nobuki; Norihiro Uemura; Tatsuya Miyake; Keizo Suzuki; Yoshiro Mikami; Masatoshi Shiiki; Shoichi Kubo
— An analytical method to determine the density of energy states of electron-emission sources (EESs) in chemical-doped MgO is described using a discharge probability model and a thermal excitation and emission model. The density of energy states for multiple types of EESs is represented by using a linear combination of Gaussian functions of which parameters are determined by the theoretical emission time constant of an exoelectron and statistical delay time ts extracted from experimental stochastic distributions of discharge delay time in plasma-display panels. When applied to Si-doped MgO, the effective number of Si EES is calculated to be 1.8 × 106 per cell. The average and standard deviations of activation energy have an energy level of 770 meV and a large value of 55 meV. In Si and H co-doped MgO, the high peak density of [H2−]0 appears at 550 meV. ts at the short time interval of 1 msec decreases and is independent of temperature due to exoelectron emission from the [H2−]0. The dependence of ts at a time interval of 10 msec on temperature becomes weak because the energy structure of the Si EES broadens significantly attributed to the electrostatic effects of the doped H atoms.
IEEE Transactions on Electron Devices | 2010
Shirun Ho; Norihiro Uemura; Shunichiro Nobuki; Tatsuya Miyake; Keizo Suzuki; Yoshiro Mikami; Masatoshi Shiiki; Shoichi Kubo
A discharge probability model is proposed to analyze the stochastic distribution of the discharge delay time. The distribution is described as a hybrid function between the exponential and Gaussian distributions and their characteristic properties, such as the emission time constant of an exoelectron and the average and standard deviations of the formative delay time. The calculated results of the probability of a successful discharge show a good agreement with the experimental results measured in plasma display panels. The analytical protocol allows the discharge delay time to be accurately separated into the statistical and formative delay times. A thermal excitation and emission model is devised to analyze the effective number and the activation energy of electron emission sources (EESs) in a MgO layer using the emission time constant of an exoelectron. The effective number of the EES, i.e., 3.79 × 105 per cell, decreases after a long time interval because of the thermal excitation; thus, the emission time constant increases significantly. The effective number of the EES after 1000 h of sustain discharge decreases to 2.07 × 104 per cell, which is 0.055 times that before the sustain discharge. This degradation is explained by 2.6-4.3 times of increase in the density of electron traps due to the ion sputtering of noble gases against the MgO surface. The emission time constant is found to decrease to 0.45 times when the wall voltage near the MgO surface is increased by 11 V, which demonstrates that the exoelectron emission can be controlled by the electric field.
SID Symposium Digest of Technical Papers | 2009
Shunichiro Nobuki; Norihiro Uemura; Masakazu Sagawa; Naoya Tokoo; Shirun Ho; Kazutaka Tsuji; Yoshiro Mikami; Masatoshi Shiiki; Keizo Suzuki
A half-pitch shifted priming cell structure to reduce address-delay-time degradation and lower power consumption has been developed. Discharge transition from a priming cell to a display cell occurred. The time constant of priming electron emission only from the priming cell did not degrade. Observed address-delay-time degradation in the display cell reduced.
Archive | 2012
Shingo Ishihara; Hiroshi Sasaki; Akitoyo Konno; Shunichiro Nobuki; Hiroki Kaneko
Archive | 2012
Hirotaka Sakuma; Sukekazu Aratani; Shunichiro Nobuki; Shingo Ishihara
Archive | 2012
Hirotaka Sakuma; Sukekazu Aratani; Shunichiro Nobuki; Shingo Ishihara
Thin Solid Films | 2014
Shunichiro Nobuki; Hironori Wakana; Shingo Ishihara; Akiyoshi Mikami
SID Symposium Digest of Technical Papers | 2013
Hirotaka Sakuma; Motoko Harada; Hironori Wakana; Shunichiro Nobuki; Masahiro Kawasaki; Shingo Ishihara; Sukekazu Aratani
SID Symposium Digest of Technical Papers | 2013
Hironori Wakana; Shunichiro Nobuki; Motoko Harada; Shingo Ishihara; Hirotaka Sakuma; Masahiro Kawasaki; Sukekazu Aratani