• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2016-2018
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• 2005

Dye-sensitized solar cell (DSC) consist of oxidation semiconduction electrode, electrolyte and counter electrode. Among these, Pt as counter electrode of DSC plays a role in helping redox reaction of iodine ions in electrolyte, also, transferring electrons into electrolyte. In this case, it is expected that characteristics of Pt electrodes strongly depend on fabrication process and its surface condition. In this study, electrochemical behavior of the electro-plated Pt electrode was compared with that of the sputtered Pt electrode, using cyclic-voltammetry and impedance spectroscopy (PARSTATE 2273, by AMETEK). Surface morphology of Pt electrode was investigated by AFM (XE-100, by PSIA). As a result, it was considered that electrochemical properties of sputtered Pt electrode is superior to that of electro-plated Pt electrode.

• Korean Chemical Engineering Research
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• 제45권5호
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• pp.433-441
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• 2007

본 논문에서는 질산염 이온의 환원을 위한 Sn의 흡착 또는 전착을 가지는 Sn-modified Pt 전극의 안정성이 평가되었다. 전극의 불안정성의 원인을 찾기 위하여 전극이 접하는 용액과 전극에 가해지는 전압에 따른 Pt 표면에서 Sn의 전기화학적 및 재료적 변화가 조사되었다. 제작된 Sn-modified Pt 전극 표면의 Sn은 hydroxide 형태로 존재하여 물, 특히 산 용액에서 방치하는 것에 의해서도 용해되어 쉽게 전극의 활성이 감소되었으며, 질산염 이온의 환원 시 전극에 $Sn(OH)_2$와 Sn의 산화-환원 평형 전압 보다 음의 전압이 가해질 때 전극 표면의 Sn hydroxide는 Sn으로 환원되어 Pt 전극 내부로 고체 확산되었고, 이는 Sn-modified Pt 전극의 활성을 감소시켰다. Sn의 고체 확산은 전극에 가해주는 전압에 비례하였다. Sn을 Pt에 코팅시키기 위하여 UPD 조건에서 흡착하는 것 보다 많은 Sn을 Pt 표면에 붙일 수 있는 Sn을 Pt에 전해 전착시키는 것이 질산염 이온의 환원하는 동안 전극의 건전성을 유지하는데 유리하였다.

• 청정기술
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• 제19권1호
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• pp.59-64
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• 2013

고분자전해질 연료전지에서 사용되는 전도성 카본에 백금이 담지된 전극촉매를 콜로이드법을 이용하여 합성하였다. 콜로이드법 합성을 위한 백금 전구체로는 PSA (platinum sulfite acid)를 사용하였으며, 고가의 전구체를 대체하기 위해 CPA (chloroplatinic acid)를 사용하여 합성하였다. PSA를 전구체로 하여 제조한 전극촉매는 10~40 wt% 담지량에서 3.5 nm 이하의 백금 입자크기와 90% 이상의 백금 담지수율을 보였다. CPA를 전구체로 사용한 경우에는 10~40 wt% 담지량에서 4.4 nm 이하의 백금 입자 크기를 보였으며 담지수율은 80% 이상이었다. 제조한 20 wt% Pt/VXC72 전극촉매로 MEA (membrane electrode assembly)를 제조하여 I-V 곡선을 측정하였으며, 제조한 전극촉매를 이용한 막전극접합체는 상용전극촉매를 사용한 경우와 동등한 성능을 보였다.

• 한국세라믹학회지
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• 제37권3호
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• pp.263-270
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• 2000

The Pt/copper oxide/n-Si electrodes were fabricated by depositing copper oxide thin film of 500${\AA}$ and very thin Pt layer on the n-type (100) Si substrate. hotoelectrochemical properties and stability profiles of the electrodes were investigated as a function of deposition time of Pt layer. As the deposition time of Pt layer increased up to 10 seconds, the photocurrent and quantum efficiency were increased and then decreased with further depositing time. The better cell stability was observed for the electrode with longer deposition time. The improvements in above photoelectrochemical properties indicate that Pt layer acts as a catalyst layer at electrode/electrolyte interface as well as a protective layer. The decreasing tendency of the photocurrent and efficiency for the electrode with Pt layer deposited above 20 seconds was explained as an increases in probbility of electron-hole pair recombination and also the absorbing photon loss at electrode surface due to the excessive thickness of Pt layer. The results were confirmed by impedance spectroscopy, mutiple cycle voltammograms and microstructural analyses.

• 전기학회논문지P
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• 제52권1호
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• pp.14-19
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• 2003

The effect of the Pt electrode and the $Pt-IrO_2$ hybrid electrode on the performance of ferroelectric device was investigated. The modified Pt thin films with non-columnar structure significantly reduced the oxidation of TiN diffusion barrier layer, which rendered it possible to incorporate the simple stacked structure of Pt/TiN/poly-Si plug. When a $Pt-IrO_2$ hybrid electrode is applied, PZT thin film properties are influenced by the thickness and the partial coverage of the electrode layers. The optimized $Pt-IrO_2$ hybrid electrode significantly enhanced the fatigue properties of the PZT thin film with minimal leakage current.

• Transactions on Electrical and Electronic Materials
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• 제6권5호
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• pp.238-242
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• 2005

The Pt counter electrode of a dye-sensitized solar cell (DSSC) plays a role in helping redox reaction of iodine ions in electrolyte, also, transferring electrons into electrolyte. In this case, it is expected that characteristics of Pt electrodes strongly depend on fabrication process and its surface condition. In this study, Pt electrodes were prepared by a electro-deposition and a RF magnetron sputtering. Electrochemical behavior of Pt electrodes was compared using cyclic-voltammetry and impedance spectroscopy. Surface morphology of Pt electrodes was investigated by FE-SEM and AFM. I-V characteristics of DSSC were measured and discussed in association with the surface properties of counter electrode. As a result, electrochemical properties of electro-deposited Pt electrode were superior to that of sputtered Pt electrode. This is likely that enlarged area of surface in electro-deposited Pt electrode in comparison with the case of sputtered Pt electrode playa role in enhancing such electrochemical properties.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.229-230
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• 2012

Platinum (Pt) has been commonly used as a counter electrode material in dye-sensitized solar cells, because it has high catalytic activity and electric conductivity as well as chemical inertness with iodide electrolyte. However, Pt is too expensive to be commercialized. Therefore, in the present study, carbon black counter electrode with Pt and carbon nano tube (CNT) was investigated. The power conversion efficiency with Pt added carbon black electrode was lower than hat of pure Pt electrode which was 6.47 %. By adding 3 wt% Pt to the carbon black counter electrode, the power conversion efficiency was maximized at 5.88 %. On them, additional adding of 1 wt % CNT, the power conversion efficiency (${\eta}$)wasincreasedupto6.21%. The reason of power conversion efficiency improvement with a proper amount of Pt and CNT was examined by comparing the impedance properties measured using EIS.

• The Korean Journal of Ceramics
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• 제6권1호
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• pp.74-77
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• 2000

Ta-doped PZT thin films prepared by reactive co-sputtering method could be transformed into single grained perovskite structure utilizing physical etching of Pt bottom electrode. It is found that PZT perovskite phase on damaged (111) Pt electrode by IMD was more easily crystallized than random oriented Pt electrode and less crystallized than (111) Pt electrode. This shows that amorphized Pt electrode surface by IMD process has an effect on crystallization of PZT perovskite phase. 40$\mu\textrm{m}\times40\mu\textrm{m}$ square shape single grain PZT array could be obtained utilizing the difference of incubation time for nucleation of rosettes between ion damaged Pt and (111) oriented Pt electrode. Single grained PZT thin films show low leakage current density of $1\times10^{-7}$ A/$\textrm{cm}^2$ and high break down field of 440kV/cm. The loss of remanent polarization after $10^{11}$ cycles was less than 15% of initial value.

• 전기화학회지
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• 제17권1호
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• pp.18-25
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• 2014

A Pt nanoparticle-decorated multiwall carbon nanotube (Pt-MWNT) electrode was prepared on Nafion by a hot-pressing at relatively low temperature. This electrode exhibited an intricate entangled, nanoporous structure as a result of gathering highly anisotropic Pt-MWNTs. Individual Pt nanoparticles were confirmed to have a polycrystalline face-centered cubic structure with an average crystal size of around 3.5 nm. From the cyclic voltammograms for hydrogen redox reactions, the Pt-MWNT electrode was found to have a similar electrochemical behavior to polycrystalline Pt, and a specific electrochemical surface area of $2170cm^2mg^{-1}$. Upon exposure to hydrogen analyte, the Pt-MWNT/Nafion electrode demon-strated a very high sensitivity of $3.60{\mu}A\;ppm^{-1}$ and an excellent linear response over the concentration range of 100-1000 ppm. Moreover, this electrode was also evaluated in terms of response and recovery times, reproducibility, and long-term stability. Obtained results revealed good sensing performance in hydrogen detection.

• Transactions on Electrical and Electronic Materials
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• 제6권4호
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• pp.177-185
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• 2005

Fatigue characteristics of lead zirconate titanate (PZT) films deposited by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) were investigated. The fatigue characteristics were investigated with respect to PZT film thickness, domain structure, fatigue pulse height, temperature, electrode materials and electrode configurations. The used top and bottom electrode materials were Pt and $RuO_2$. In the fatigue characteristics with fatigue pulse height and PZT film thickness, the fatigue rates are independent of the applied fatigue pulse height at the electric field regions to saturate the P-E hysteresis and polarization $(P^*,\;P^A)$ characteristics. The unipolar and bipolar fatigue characteristics of PZT capacitors with four different electrode configurations $(Pt//Pt,\;Pt//RuO_2,\;RuO_2//Pt,\;and\;RuO_2//RuO_2)$ were also investigated. The polarization-shifts during the unipolar fatigue and the temperature dependence of fatigue rate suggest that the migration of charged defects should not be expected in our CVD-PZT films. It seems that the polarization degradations are attributed to the formation of charged defects only at the Pt/PZT interface during the domain switching. The charged defects pin the domain wall at the vicinity of Pt/PZT interface. When the top and bottom electrode configurations are of asymmetric $(Pt//RuO_2,\;RuO_2//Pt)$, the internal fields can be generated by the difference of charged defect densities between top and bottom interfaces.