• Journal of Information Display
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• v.11 no.4
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• pp.165-168
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• 2010

A solution-processed multicomponent oxide, yttrium hafnium zinc oxide (YHZO), was synthesized and deposited as a gate insulator. The YHZO film annealed at $600^{\circ}C$ contained an amorphous phase based on the results of thermogravimetry, differential thermal analysis, and X-ray diffraction. The electrical characteristics of the YHZO film were analyzed by measuring the leakage current. The high dielectric constant (16.4) and high breakdown voltage (71.6 V) of the YHZO films resulted from the characteristics of $HfO_2$ and $Y_2O_3$, respectively. To examine if YHZO can be applied to thin-film transistors (TFTs), indium gallium zinc oxide TFTs with a YHZO gate insulator were also fabricated. The desirable characteristics of the YHZO films when used as a gate insulator show that the limitations of the general binary-oxide-based materials and of the conventional vacuum processes can be overcome.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.3
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• pp.174-180
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• 1998

In this work, the properties of FRP, which is applied recently in the composite insulating materials, by thermal treatment were investigated. The specimens were epoxy glass laminates fabricated by thermal press method and had the volume content of 46[%] cutted $45^{\circ}C$ in the fiber direction and 1.0[mm] thickness. The experimental results showed that the amount of weight loss, wettability, surface potential, and surface resistivity increased up to 200[$^{\circ}C$] as a function of temperature. Usually, most degradations caused the hydrophilic to decrease the contact angle. But, in this work on thermal-degradated FRP, we can confirm the introduction of hydrophobic properties by cross-linking and the ablation of polar small-molecules rather than chain scission and oxidation. Finally, weight loss and contact angle increased. These phenomena show the existence of hydrophobic surface. With the change to the hydrophobic surface and the electrical potential and resistivity on FRP surface increased. But, the dielectric properties and tensile stength are decreased.

• Electrical & Electronic Materials
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• v.9 no.6
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• pp.551-557
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• 1996

To decrease the hysteresis of electric field induced strain, $Y_{2}$ $O_{3}$ dopant of which amount is 0-0.8wt% was added to the (P $b_{0.73}$B $a_{0.27}$)(Z $r_{0}$ 75/ $Ti_{0.25}$) $O_{3}$ ceramics. Electromechanical coupling coefficients of the specimen with 0.1 Wt% $Y_{2}$ $O_{3}$ were $k_{p}$=26.9% and $k_{31}$ =20.4%, which exhibited the maximum value at the constant bias electric field of 10 kV/cm. At the same $Y_{2}$ $O_{3}$ addition amount, electric field piezoelectric constant ( $d_{3l}$) and strain(.DELTA.l/l) showed the maximum values of 139.6*10$^{-12}$ [C/N] and 126*10$^{-6}$ .DELTA. l/l respectively at 10 kV/cm electric field. And the hysteresis of strain showed the minimum value of 17.5%. So, we propose that it is possible to apply PBZT system with $Y_{2}$ $O_{3}$ dopant to the electrostrictive actuator.r.r.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1096-1099
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• 2004

The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system BaO-ZnO-$B_2O_3$-$V_2O_5$. DTA, and XRD were used to characterize BaO-ZnO-$B_2O_3$-$V_2O_5$ glasses. In this present study, PbO free paste had thermal expansion of $74\times10^{-7}/^{\circ}C$, DTA softening point of $460^{\circ}C$, and firing condition of $520^{\circ}C$, 20min

• Transactions on Electrical and Electronic Materials
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• v.8 no.3
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• pp.139-142
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• 2007

Organic field-effect transistor (FET) based on a copper Phthalocyanine (CuPc) material as an active layer and a $SiO_2$ as a gate insulator were fabricated and analyzed. We measured the typical FET characteristics of CuPc in air. The electrical characteristics of the CuPc FET device were analyzed by a Maxwell-Wagner model. The Maxwell-Wagner model employed in analyzing double-layer dielectric system was helpful to explain the C-V and I-V characteristics of the FET device. In order to further clarity the channel formation of the CuPc FET, optical second harmonic generation (SHG) measurement was also employed. Interestingly, SHG modulation was not observed for the CuPc FET. This result indicates that the accumulation of charge from bulk CuPc makes a significant contribution.

• Membrane and Water Treatment
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• v.6 no.5
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• pp.351-363
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• 2015

To increase the surface hydrophilicity of PVDF membranes, in this paper, an electric enhancing method was adopted to treat PVDF nascent membranes during the phase inversion process. It was found that when PEG 600 was taken as the additive, the surface water contact angle of the PVDF membrane treated under 2 kV electric field was decreased from $84.0^{\circ}$ to $65.7^{\circ}$. The reason for the surface elements change of the PVDF membranes prepared under the electric field was analyzed in detail with the dielectric parameters of the polymer dope solutions. Results from BSA adsorption experiment showed that the antifouling ability of the external electric field-treated membranes was distinctly enhanced when compared with that of the untreated membranes. The amount of BSA adsorbed by the treated membranes was lower by 38-43%. Compared with the common chemical reaction methods to synthesize hydrophilic additives or membrane materials, the electric field-assisted processing method did not involve any additional chemical synthesis process and it was capable of realizing better hydrophilicity.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.10
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• pp.91-97
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• 1998

The modulation performance of 10 Gbps electro-absorption InGaAsP/InGaAsP strain compensated MQW (Multiple Quantum Well) modulator module depends on the modulator as well as the package parasitics. The high frequency package parasitics resulting from various structural discontinuities, limit the modulation bandwidth and increase the chirp-parameter. Therefore, we propose the double bondwires embedded in dielectric materials to minimize the bondwire parasitics. Using the proposed structure with 50 $\Omega$ terminating resistor, the modulation bandwidth is greatly increased by 125 % than the bare chip and the chirp-parameter is also reduced. This technique can be used in optimizing the package of high speed external modulators.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.6
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• pp.120-126
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• 1996

In the present study, we have studied on the characteristics of BST thin films with various Ba/Sr ratios by using sol-gel method. Barium-acetate, strontium-acetate and titanium isopropoxide are used as starting materials to fabricate BST thin films by sol-gel method. The fabrication conditions are estabilished through the TG-dT analyses and XRD measurements. BST thin films with the Ba/Sr ratios of 90/10, 70/30, 50/50 and 30/70 were deposited on the Pt/Ta/SiO$_{2}$Si substrate with the estabilished sol-gel process, and their characteristics were examined. The relative permittivity and the leakage current density at 5V vary from 287 to 395 and from 2.3 to 220${\mu}$A/cm$^{2}$, respectively, with various Ba/Sr ratio. Among the films investigatd in this research, BST (70/30) thin film shows the best relative permittivity and dielectric loss of BST (70/30) thin film are 395 and 0.045, respectively and the leakage current density at 5V is 2.3${\mu}$A/cm$^{2}$.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.395-398
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• 2018

In this work, profound microscale behaviors of block copolymer and polymer blend under electric field were investigated using microscopic methods and compared systematically. To this end, both the block copolymer and blend containing polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) were introduced. The two polymers have a similar dielectric constant. Under an identical experimental condition such as temperature, film thickness, field intensity, and exposure time, the polymer blend responded more sensitively than the block copolymer. The presence of covalent bond suppressed the mobility of constituents in block copolymer. This study will be essential for future research activities regarding behaviors of polymeric materials under external fields.

• Journal of the Korean Vacuum Society
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• v.5 no.1
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• pp.62-66
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• 1996

$(Ba_{1-x}Sr_xTiO_3$ (BST) thin films have been grown on Pt-coated MgO by metal -organic chemical vapor deposition. X-ray diffraction results showed that BST films were grown on a Pt/MgO substrate with (100) preferred orientation perpendicular to the surface. The lineawr relationship of P-E curve obtained form hysteresis loop measurement indicated that the BST films had a Curie transitions below room temperature . Films deposited at $900^{\circ}C$ exhibited a smooth and dense microstructure, a dielectric constant of 202, and a dissipation facotr of 0.02 at 100kHz. The leakage current density of the BST films is about $2\times10^{-10} \;A/\textrm{cm}^2$$ at an applied electric field of 0.2 MV/cm. The electrical behavior on the current-voltage characteristics is well explained by the bulk-limited Pool-Frenkel emission.