• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.52-56
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• 2006

Punching tools like an electrodes are made by milling or etching or EDM. These methods had time consuming, low efficiency and air pollution. So, we have developed a shearing device which counter punching method for burrless cutting of micro wire. Using the straightened SUS304 wire with $200{\mu}m$ diameter, we confirmed the tendency of the shear plane for punch tools. It was impossible to completely remove the bun in the shearing process. In order to minimize the burr size and fine shear plane, we have accomplished the various experiment conditions such as the U-groove, the effect of the counter punch, shear angle and clearance. The results of the experiments show that indentation, slip plane and bent shape were related to the shear angle and clearance.

• Journal of Electrochemical Science and Technology
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• v.11 no.1
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• pp.41-49
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• 2020

In this study poly(carbazole) films deposited on stainless steel have been investigated as electrode material for supercapacitor applications. Poly(carbazole) films were electrodeposited using cyclic voltammetry in presence of lithium, sodium and tetrabutylammonium perchlorate salts. Poly(carbazole) films doped with perchlorate anions having different counter cations were characterized by SEM, ATR-FTIR and solid state conductivity measurements. Capacitive behaviours of PCz coated steel electrodes were tested by cyclic voltammetry, charge-discharge analysis and electrochemical impedance spectroscopy. It was found that counter cation of the dopant is significantly effective on the capacitive performance on the obtained PCz films and the PCz film synthesized from lithium perchlorate has the better capacitive performance than the poly(carbazole)s synthesized from sodium perchlorate and tetrabutylammonium perchlorate salts.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1236-1237
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• 2008

Carbon nanotube(CNT) materials are expected a stable current collector without the phenomena such as oxidizing and melting of grid by redox electrolyte and with low cost. In this paper, two types of dye-sensitized solar cells(DSSCs) with Pt abd CNT as a counter electrode were fabricated, then the energy conversion efficiency characteristics were investigated. The main purpose of this study is to find out the possibility of CNT material as cheap current collector of a large scale DSSC module. In addition, the Hall coefficient were measured by using FCM analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.385-388
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• 2004

염료감응형 태양전지는 다공질 $TiO_2$ 전극막, 광감응형 염료, 전해질, 상대전극으로 구성된, 전기화학적 원리를 응용한 신형태양전지이다. 본 연구에서는 백금 상대전극의 제조 방법에 따른 태양전지의 효율 및 특성을 비교하였다. 본 연구에 사용된 백금 상대전극막의 제조 방법은 스퍼터링(sputtering)법 과 전기도금(electroplating)법이다. 두 상대전극의 전기화학적 특성은 cyclic voltammetry와 Imepedance spectroscopy 측정을 통하여 비교하였다. 두 전극이 태양전지의 효율 및 특성에 미치는 영향은 단위 셀 태양전지를 제조하여 단파장 하에서 $350nm{\sim}700nm$의 파장별 효율을 측정함으로써 조사하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2008.05a
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• pp.44.2-44.2
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• 2008

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.385-385
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• 2009

Uniform polyaniline nanofibers (PANI NFs), and chemically doped sulfamic acid(SFA) PANI NFs, synthesized via template free interfacial polymerization process, were used as new counter electrodes materials for the fabrication of the highly-efficient dyesensitized solar cells (DSSCs). The PANI NFs based fabricated DSSCs exhibited a solarto-electricity conversion efficiency of ~ 4.02% while, the SFA doped PANI NFs based DSSC demonstrated ~ 27% improvement in the solar-to-electricity conversion efficiency. The obtained solar-to-electricity conversion efficiency for SFA doped PANI NFs based DSSC was 5.47% under 100mW/$cm^2$(AM1.5). The enhancement in the conversion efficiency was due to the incorporation of SFA into the PANI NFs which resulted to the higher electrocatalytic activity for the $I^{3-}/I^-$ redox reaction.

• Journal of Electrochemical Science and Technology
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• v.10 no.1
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• pp.55-60
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• 2019

Herein, the effect of counter anions on the formation of a solid electrolyte interphase (SEI) in a propylene carbonate (PC)-based electrolyte solution was investigated. Although the reversible capacities were different, reversible intercalation and de-intercalation of lithium ions occurred in the graphite negative electrode in the PC-based electrolyte solutions containing 1 M $LiClO_4$, $LiPF_6$, $LiBF_4$, and $LiCF_3SO_3$ at low temperature ($-15^{\circ}C$). This indicated that the surface films acted as an effective SEI to suppress further co-intercalation and decomposition reactions at low temperature. However, the SEIs formed at the low temperature were unstable in 1 M $LiPF_6$ and $LiBF_4/PC$ at room temperature ($25^{\circ}C$). On the other hand, increasing reversible capacity was confirmed in the case of $LiCF_3SO_3/PC$ at room temperature, because the SEI formed at the low temperature was still maintained. These results suggest that counter anions are an important factor to consider for the formation of effective SEIs in PC-based electrolyte solutions.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.785-791
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• 2023

Copper sulfide (Cu_xS) has been extensively utilized as a counter electrode (CE) material for quantum dot solar cells (QDSCs) due to its exceptional catalytic activity for polysulfide electrolytes. The typical fabrication method of Cu₂S CEs based on brass substrate is dangerous, involving the use of a highly concentrated hydrochloric acid solution in a relatively high temperature. In contrast, electroplating presents a safer alternative by employing a less acidic solution at a room temperature. In addition, the electroplating method increases the probability of obtaining CEs of consistent quality compared to the brass method. In this study, the optimized electroplating cycle for CuS CEs in QDSCs has been studied for the highly efficient photovoltaic performances. The QDSCs, featuring electroplated CuS CEs, achieved an impressive efficiency of 7.18%, surpassing the conventional method employing brass CEs, which yielded an efficiency of 6.62%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.10
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• pp.912-917
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• 2007

Many electrochemical power devices such as solid state batteries and solid oxide fuel cell have been studied and developed for solving energy and environmental problems. An amperometric gas sensor usually generates sensing signal of electric current along the proportion of the concentration of target gas under the condition of limiting current. For narrow variations of gas concentration, the amperometric gas sensor can show higher precision than a potentiometric gas sensor does. In additional, cross sensitivities to interfering gases can possibly be mitigated by choosing applied voltage and electrode materials properly. In order to improve the sensitivity to $NO_2$, the device was attached with Au reference electrode to form the amperometric gas sensor device with three electrodes. With the fixed bias voltage being applied between the sensing and counter electrodes, the current between the sensing and reference electrodes was measured as a sensing signal. The response to $NO_2$ gas was obviously enhanced and suppressed with a positive bias, respectively, while the reverse current occurred with a negative bias. The way to enhance the sensitivity of $NO_2$ gas sensor was thus realized. It was shown that the response to $NO_2$ gas could be enhanced sensitivity by changing the bias voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.433-434
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• 2008

Until now, many studies have been carried out on $TiO_2$ electrode, counter electrode, sensitizer and electrolyte to improve dye-sensitized solar cell(DSSC)'s performance. It was known that surface area of the $TiO_2$ are of paramount importance in determining the cell efficiency. In this experiment, $TiO_2$ working electrodes were sintered at four different temperatures (400, 450, 500 and $550^{\circ}C$) for 55 minutes in ambient atmosphere. Also these electrodes were sintered at four different times (40, 55, 70, 85minutes) in temperature where shows the highest efficiency. I-V characteristics of DSSC made up of different working electrodes were studied using solar simulator.