• Journal of the Korean Ceramic Society
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• v.53 no.3
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• pp.338-342
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• 2016

ZnO thin film co-doped with F and Al was prepared on a glass substrate via simple non-alkoxide sol-gel spin coating. For a fixed F concentration, the addition of Al co-dopant was shown to reduce the resistivity mainly due to an increase in electrical carrier density compared with ZnO doped with F only, especially after the second post-heat-treatment in a reducing environment. There was no effective positive contribution to the reduction in resistivity due to the mobility enhancement by the addition of Al co-dopant. Optical transmittance of the ZnO thin film co-doped with F and Al in the visible light domain was shown to be higher than that of the ZnO thin film doped with F only.

• Journal of the Korean Ceramic Society
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• v.29 no.2
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• pp.101-106
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• 1992

Sintering behavior, distribution of dopant oxides and electrical properties in the ZnO-Bi2O3-CoO-Sb2O3 and ZnO-Bi2O3-CoO-Sb2O3-Cr2O3 systems were studied. The linear shrinkage of ZnO varistors from 850 to 950$^{\circ}C$ was related to the decomposition reaction (py\longrightarrowsp+Bi2O3) of the pyrochlore phase. In the distribution of the dopant oxides (CoO, Sb2O3, Cr2O3), Co distribute uniformly throughout the sample, the distribution of Sb coincided with small particles (spinel phase, Zn7Sb2O12), and Cr distributed very consistently with Sb. The increase in breakdown voltage, due to the addition of Cr2O3, was not only attributed to the decrease in the ZnO grain size but also to the solution of Cr2O3 in the spinel phase. The leakage current (80% V60 ${\mu}\textrm{A}$) was increased by the addition of Cr2O3.

• Journal of the Semiconductor & Display Technology
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• v.6 no.2 s.19
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• pp.19-23
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• 2007

The blue emitting OLEDs using TMP-BiP[(4'-Benzoylferphenyl-4-yl)phenyl-methanone-Diethyl(biphenyl-4-ymethyl) phosphonate] host and DJNBD-1 dopant have been fabricated and characterized. In the device fabrication, 2-TNATA [4,4',4"-tris(2-naphthylphenyl-phenylamino)-triphenylamine] as a hole injection material and NPB [N,N'-bis(1-naphthyl)N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] as a hole transport material were deposited on the ITO(indium tin oxide)/glass substrate by vacuum thermal evaporation method. Followed by the deposition, blue color emission layer was deposited using TMP-BiP as a host material and DJNBD-1 as a dopant. Finally, small molecule OLEDs with structure of $ITO/2-TNATA/NPB/TMP-BiP:DJNBD-l/Alq_3/LiF/Al$ were obtained by in-situ deposition of $Alq_3$, LiF and Al as the electron transport material, electron injection material and cathode, respectively. The effect of dopant into host material of the blue OLEDs was studied. The blue OLEDs with DJNBD-1 dopant showed that the maximum current and luminance were found to be about 34 mA and $8110\;cd/m^2$ at 11 V, respectively. In addition, the color coordinate was x=0.17, y=0.17 in CIE color chart, and the peak emission wavelength was 440 nm. The maximum current efficiency of 2.15 cd/A at 7 V was obtained in this experiment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.33-34
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• 2005

In this study, in odor to develop low temperature sintering multilayer piezoelectric actuator and ultrasonic vibrator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3$ and $Na_2CO_3$ as sintering aids and their piezoelectric and dielectric characteristics were investigated according to the addition of dopant CuO and $Fe_2O_3$, respectively. The CuO added PMN-PNN-PZT ceramics improved mechanical quality factor Qm due to the acceptor doping effect. And also, $Fe_2O_3$ reacted as softner in this composition system in addition to the increase of grain size and sinterability. Taking into consideration electromechanical coupling factor kp of 0.62, dielectric constant $\varepsilon_r$, of 1275, Piezoelectric $d_{33}$ constant of 377[pC/N] and mechanical quality factor Qm of 975, it was concluded that the ceramics with the $Fe_2O_3$, added composition sintered at 900[$^{\circ}C$] were best for the multilayer piezoelectric actuator and ultrasonic vibrator application.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1319-1322
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• 2008

$CsN_3$ was developed as a novel n doping material with air stability and low deposition temperature. Evaporation temperature of $CsN_3$ was similar to that of common hole injection material and it worked well as a n dopant in electron transport layer. Driving voltage was lowered and high power efficiency was obtained in green phosphorescent devices by using $CsN_3$ as a dopant in electron transport layer. It could also be used as a charge generation layer in combination with $MoO_3$. In addition, n doping mechanism study revealed that $CsN_3$ is decomposed into Cs and $N_2$ during evaporation. This is the first work reporting air stable and low temperature evaporable n dopant in organic light-emitting diodes.

• Journal of Ocean Engineering and Technology
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• v.24 no.6
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• pp.81-85
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• 2010

The effects of co-doping with complex dopants of softeners, $La^{+3}$ and/or $Nb^{+5}$, and a hardener, $Fe^{+3}$, on the microstructural and piezoelectric properties of PZT ceramics with a composition of a rhombohedral-tetragonal morphotropic phase boundary, $PbZr_{0.53}Ti_{0.47}O_3$, were investigated. Unlike single-element doping, the complex doping of both the softener and hardener ions led to various compensation effects for the piezoelectric properties of the PZT ceramics. For 0.5 wt.% $La_2O_3$ softener and/or 0.5 wt.% $Nb_2O_5$ doped compositions, there were apparent hardener doping (compensation) effects for an addition of over 1.0 wt.% $Fe_2O_3$. For the $La_2O_3$ and/or $Nb_2O_5$ doped composition, the co-dopant $Fe_2O_3$ addition led to lower kp and $\varepsilon$r, and increased $Q_m$ values. The prepared PZT ceramics modified with complex soft dopants, $La^{+3}$ and $Nb^+$, as well as a hard dopant, $Fe^{+3}$, showed that the piezoelectric properties were stable with the compositional variations, which made it possible to establish piezoelectric performances with higher reliability and reproducibility. The most improved piezoelectric properties of enhanced $Q_m$ with $\varepsilon_r$ remaining higher $k_p$, were obtained in the PZT composition complexly doped with $La^{+3}$ and $Fe^{+3}$. From the results obtained in this study, the properties of compositionally modified PZT ceramics can also be tailored over a wider range by changing the dopant compositions to meet the specific requirements for underwater or other applications.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.183-192
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• 1980

Oxidation reactions of carbon monoxide on $SnO_2$, Sb-doped $SnO_2$, and Pt catalyst were studied. The oxidation reaction was found to be first order with respect to both CO and O$_2$ on $SnO_2$ and Sb-doped $SnO_2$ catalysts, and to be of half order on Pt catalyst. A small addition of Sb to $SnO_2$ (depant composition: 0.05∼0.1 mol %) increased the rate of oxidation. On the contrary, a large addition decreased the rate. From the rate expression of oxidation on Pt catalyst, the inhibition effect of carbon monoxide on the rate of oxidation was deduced. The experimentally obtained activatio energies were 5.7 kcal for the Sb doped $SnO_2$ catalyst (dopant composion: 0.05 mole%), and 6.4 kcal for the Pt catalyst. A possible reaction mechanism was proposed from the experimentally obtained kinetic data.

• Journal of the Korean Ceramic Society
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• v.33 no.1
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• pp.65-73
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• 1996

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.11-16
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• 2007

The existence of grooves on the surface of bond coat has significant effect on the instability of thermal barrier system. In this work, the thermal-mechanical fatigue experiments were performed under various thermal and mechanical loads for FeCralloy specimens with and without yttrium dopant to observe the deformation of surface grooves. The effect of temperature, fatigue load and the ratio of curvature on the deformation of grooves were investigated. As the results, it has been found that the higher load level and the higher curvature ratio induces the larger deformation near the grooves. However, the addition of yittrium dopant induces the adverse results.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1433-1436
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• 2007

Using a blue emitting DPVBi material and red dopant DCJTB, WOLEDs with and without green emitter C6 added in ETL or HTL have been fabricated. The chromaticity color index of WOLEDs without C6 depends strongly on the doping concentration. In addition, manipulating thickness of emitting layer is similar effect such as controlling weight concentration of dopant. While the white color of WOLEDs with C6 added in ETL or HTL depend on position of C6. WOLED of three colors added green dye have been shown turn-on voltage of 3.25V, and EL efficiency 3.05cd/A @9V, $8102\;cd/m^2$, CIE coordinates (0.30, 0.32).