• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.139-143
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• 1997

The doping effects of Mg and/or Fe ions on congruent LiNbO$_3$ single crystal growth were studied in order to clarify the roles of MgO in Fe doped LiNbO$_3$ single crystals. The effective distribution coefficienct of Fe was found decreased drastically from 0.85 to 0.5 by the addition of MgO into the LiNbO$_3$ melt. M ssbauer spectra revealed that the addition of MgO reduces the occurrence of Fe2+ ions during growth in air. Therefore, it is likely that there would be two important roles of MgO in Fe doped LiNbO$_3$. One is to suppress the incorporation of all Fe ions, and the other is to reduce the concentration of Fe2+ ions among the total Fe ions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.201-204
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• 1999

Polarization mode dispersion (PMD) restrict the bend-width of single mode optical filer, and it is important parameter in the optical fiber having long-length. Although fiber has perfect circular symmetry, fiber bending, twisting and laws governing manufacture cause additional Polarization mode dispersion. The effect of polarization mode dispersion in general single mode fiber of long length is discussed in this paper. Measurement of PMD with random mode coupling were conducted in two kind of fibers using different laws governing manufacture and interferometric method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.135-135
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• 2009

In this work we compared the electrical characteristic of single gate and dual gate in MIC-TFT. We fabricated p-channel TFTs based on MIC structure. In mobility, dual gate ($61.35cm^2/Vsec$) got a higher value than single gate ($55.96cm^2/Vsec$). In $I_{on}/I_{off}$ dual gate ($6.94{\times}10^6$) got a higher value than single gate ($1.72{\times}10^6$) too. In $I_{off}$, dual gate got a lower value than single gate. Therefore, dual gate is good and less power consumption than single gate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.249-250
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• 2008

In this paper, we propose the single polycrystalline silicon flash EEPROM IC with a new structure which does not need the high voltage switching circuit. The design of high voltage switching circuits which are needed for the data program and erase, has been an obstacle to develop the single-poly EEPROM. Therefore, we has proposed the new cell structure which uses the low voltage switching circuits and has designed the full chip. A new single-poly EEPROM cell is designed and the full chip including the control block, the analog block, row decoder block, and the datapath block is designed. And the each block is verified by using the computer simulation. In addition, the full chip layout is performed.

• Electronic Materials Letters
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• v.14 no.6
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• pp.774-783
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• 2018

Full maximum-entropy mobility-spectrum analysis (FMEMSA) is the best algorithm among mobility spectrum analyses by which we can obtain a set of partial-conductivities associated with mobility values (mobility spectrum) by analyzing magnetic-field-dependent conductivity-tensors. However, it is restricted to a direct band-gap semiconductor and should be modified for materials with other band structures. We developed the modified version of FMEMSA which is appropriate for a material with a single anisotropic valley, or an indirect-band-gap semiconductor quantum-well with a single non-degenerate conduction-band valley e.g., (110)-oriented AlAs quantum wells with a single anisotropic valley. To demonstrate the reliability of the modified version, we applied it to several sets of synthetic measurement datasets. The results demonstrated that, unlike existing FMEMSA, the modified version could produce accurate mobility spectra of materials with a single anisotropic valley.

• Industrial Engineering and Management Systems
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• v.12 no.3
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• pp.181-189
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• 2013

This paper proposes a two-phase genetic algorithm (GA) to solve the problem of obtaining an optimum configuration of a paired single row assembly line. We pair two single-row assembly lines due to the shared usage of several workstations, thus obtaining an optimum configuration by considering the material flow of the two rows simultaneously. The problem deals with assigning workstations to a sequence and selecting the best arrangement by looking at the length and width for each workstation. This can be considered as an enhancement of the single row facility layout problem (SRFLP), or the so-called paired SRFLP (PSRFLP). The objective of this PSRFLP is to find an optimal configuration that seeks to minimize the distance traveled by the material handler and even the use of the material handler itself if this is possible. Real-world applications of such a problem can be found for apparel, shoe, and other manual assembly lines. This research produces the schematic representation solution using the heuristic approach. The crossover and mutation will be utilized using the schematic representation solution to obtain the neighborhood solutions. The first phase of the GA result is recorded to get the best pair. Based on these best matched pairs, the second-phase GA can commence.

• Journal of Sensor Science and Technology
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• v.14 no.5
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• pp.331-336
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• 2005

The influence of water molecule on the electrical properties of single-walled carbon nanotube field effect transistors (SWNT-FETs) was reported. Conductance suppression was observed with the increase of the humidity. This can be explained by doping of the SWNT-FETs, which has p-type semiconductor characteristic, with the water molecules acting as an electron donor. However, after 65 % of humidity, conductance of the SWNT-FETs started to increase again, due to the opening of electron channels. Upon annealing at $400^{\circ}C$ in Ar atmosphere, conductance increases more than 500 %, and the threshold voltage shifts toward further positive gate voltages. The results of this experiment support possible application of single-walled carbon nanotubes for humidity sensing material.

• Proceedings of the Plant Resources Society of Korea Conference
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• v.18 no.1
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• pp.143-143
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• 2005

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.466-474
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• 2021

[011] poled ternary Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PIN-PMN-PT) single crystals have been investigated for active materials for acoustic transducers because of their high piezoelectric properties in both shear and transverse modes. In order to use [011] poled PIN-PMN-PT single crystals for acoustic transducers, the characterization of full-matrix material properties is required. In this study, full sets of compliance, dielectric, and piezoelectric constants of [011] poled rhombohedral PIN-PMN-PT were measured by a resonance method. Dimensions and geometries of 12 samples were proposed for measuring 17 independent material constants of [011] poled rhombohedral PIN-PMN-PT single crystals. Two sets of samples with different PT concentrations, 0.24PIN-0.49PMN-0.27PT and 0.24PIN-0.46PMN-0.30PT, were fabricated and their material properties were measured. Measured impedance spectra and simulated impedance spectra of the samples were compared to check the accuracy of the measurements.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.171-174
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• 2004

The stochiometric $AgGaSe_2$ polycrystalline mixture of evaporating materials for the $AgGaSe_2$ single crystal thin film was prepared from horizontal furnace. To obtain the single crystal thin films, $AgGaSe_2$ mixed crystal and semi-insulating GaAs(100) wafer were used as source material and substrate for the Hot Wall Epitaxy (HWE) system, respectively. The source and substrate temperature were fixed at $630^{\circ}C$ and $420^{\circ}C$, respectively. The thickness of grown single crystal thin films is $2.1{\mu}m$. The single crystal thin films were investigated by photoluminescence and double crystal X-ray diffraction(DCXD) measurement. The carrier density and mobility of $AgGaSe_2$ single crystal thin films measured from Hall effect by van der Pauw method are $4.89{\times}10^{17}\;cm^{-3},\;129cm^2/V{\cdot}s$ at 293K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the $AgGaSe_2$ single crystal thin film, we have found that the values of spin orbit splitting ${\Delta}S_o$ and the crystal field splitting ${\Delta}C_r$ were 0.1762 eV and 0.2494 eV at 10 K, respectively. From the photoluminescence measurement of $AgGaSe_2$ single crystal thin film, we observed free excition $(E_X)$ observable only in high quality crystal and neutral bound exciton $(D^o,X)$ having very strong peak intensity And, the full width at half maximum and binding energy of neutral donor bound excition were 8 meV and 14.1 meV, respectively. By Haynes rule, an activation energy of impurity was 141 meV.