• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1432-1433
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• 2011

본 연구에서는 나노입자 이산화티타늄을 이용한 광전화학셀을 제작하여 제작된 광전기화학셀의 광전변환특성을 연구 하였다. 광전기화학셀을 제작함에 있어 광전극에는 나노입자 이산화티타늄을 페이스트로 하여 스크린 프린팅 하고 열처리 하였으며 상대전극의 경우 $H_2PtCl_6$를 2-propanol에 10mM로 녹인 용액을 도포하였다. 나노 페이스트와 용액처리를 한 광전극과 상대전극을 접합 후, 전해질을 주입 후 밀봉하여 셀을 제작하였다. 이때 사용된 전해질은 LiI, $I_2$, t-butylpyridine, 1-butyl-3-methylimidazolium iodide, 3-methoxypropionitrile이 사용되었다. 제작한 셀의 광전 변환 효율은 개방전압 Voc는 16.3v, 충진율 FF는 0.65로 나타났으며 이때의 변환 효율 7.55%로 나타났다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.360-361
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• 2008

A new kind of SBM co-polymer binder as styrene, n-butyl acrylate, and methacrylic acid (SBM) monodisperse co-polymer binder materials basted on $TiO_2$ pastes was synthesized and this $TiO_2$ pastes were applied of dye-sensitized solar cells (DSSCs). The SBM co-polymer binder was prepared by soap-free emulsion copolymerization using a PEG-EEM macromonomer. The photoanodes were characterized by morphology investigated from field emission scanning electron microscopy (FE-SEM). The photoelectrochemical properties of the thin films and the performance of DSSCs were measured by photovoltaic-current density. DSSC based on the emulsion co-polymer binder was obtained conversion efficiency of 7.1% under irradiation of AM 1.5($100mWcm^{-2}$).

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1485-1486
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• 2011

A layer of $TiO_2$ thin film less than ~500nm in thickness, as a blocking layer, was coated by sol-gel method directly onto the anode electrode to be isolated from the electrolyte in dye-sensitized solar cells (DSCs). This is to prevent the electrons from back-transferring from the electrode to the electrolyte (I-/I3-). The effects of heat treatment conditions of the gel and as-coated film on the thickness and consolidation to substrate were studied. The flexible DSCs were fabricated with working electrode of Ti thin foil coated with blocking $TiO_2$ layer, dye-attached mesoporous $TiO_2$ film, gel electrolyte and counter electrode of Pt-deposited indium doped tin oxide/polyethylene naphthalate (ITO/PEN). The photo-current conversion efficiency of the cell was 5.3% ($V_{oc}=0.678V$, $J_{sc}=12.181mA/cm^2$, ff=0.634) under AM1.5, 100 mW/$cm^2$ illumination.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.120.2-120.2
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• 2011

The improvement of solar energy-to-electricity conversion efficiency has continued to be an important research area of dye-sensitized solar cells (DSSCs). The mechanism of DSSCs is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline TiO2 or ZnO. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO band gaps of dye moleculed in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. Organic dyes, because of their many advantages, such as high molar extinction coefficients, convenience of customized molecular design for desired photophysical and photochemical properties, inexpensiveness with no transition metals contained, and environment-friendliness, are suitable as photosensitizers for DSSC. We believe that practically useful organic dye photosensitizers can be produced by exploiting electron donor/acceptor system with proper length of ${\pi}$-conjugation in a chromophore to control the absorption wavelength and enhance the photovoltaic performance. In this research, We designed and synthesized organic dyes also investigated the photoelectrochemical properties of a series of ionic dyes in DSSCs.

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.953-958
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• 2007

Anchoring quantum dots (QDs) onto thermodynamically stable, large band gap oxide semiconductors is a very important strategy to enhance their quantum yields for solar energy conversion in both visible and near-IR regions. We describe a general procedure for anchoring a few chalcogenide QDs onto the titanium oxide layer. To anchor the colloidal QDs onto a mesoporous TiO2 layer, linker molecules containing both carboxylate and thiol functional groups were initially attached to TiO2 layers and subsequently used to capture dispersed QDs with the thiol group. Employing the procedure, we exploited cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) as inorganic sensitizers for a large band gap TiO2 layer of dye-sensitized solar cells (DSSCs). Their attachment was confirmed by naked eyes, absorption spectra, and photovoltaic effects. A few QD-TiO2 systems thus obtained have been characterized for photoelectrochemical solar energy conversion.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.584-587
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• 2011

In this work, the $TiO_2$ and $SnO_2$ thin films as blocking layers were coated directly onto the metal-mesh electrode surface to prevent unnecessary inflow of back-transfer electrons from the electrolyte ($I^-/I_3^-$) to the metal-mesh electrode. The DSCs were fabricated with working electrode of SUS mesh coated with blocking $TiO_2$ and $SnO_2$ layers, dye-attached mesoporous $TiO_2$ film, gel electrolyte and counter electrode of Pt-deposited F:$SnO_2$. From the experimental result, it was ascertained that the efficiency of metal electrode coated with $TiO_2$ by Dip-coating was superior to that of metal electrode coated with $SnO_2$ by Dip-coating and screen printing with the results of experiments. The photo-current conversion efficiency of the cell obtained from optimum fabrication condition was 3% ($V_{oc}$=0.61V, $J_{sc}$=11.64 mA/$cm^2$, ff=0.64) under AM1.5, 100 mW/$cm^2$ illumination.

• Journal of Energy Engineering
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• v.15 no.2 s.46
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• pp.96-106
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• 2006

Among several different hydrogen production technologies, solar hydrogen system for water splitting is the only clean and sustainable energy supplier. Hydrogen production by water-splitting utilizing solar energy has attracted considerable interest since the pioneering work of Honda and Fujishima in 1979, who discovered that water can be photo-electrochemically decomposed into hydrogen and oxygen using a semiconductor ($TiO_2$) electrode under UV irradiation. Most efforts to utilize solar ray lead to explore visible responding photocatalysts, PEC cells and other fusion technology like bio-photocatalytic conversion. In this paper, photon utilization technologies for water splitting have been briefly reviewed except solar thermal utilization technology.

• Journal of the Korean institute of surface engineering
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• v.55 no.1
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• pp.1-8
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• 2022

Titanium dioxide (TiO₂) is one of the most intensively investigated materials in materials science. Mostly, TiO₂ has been used in the form of nanoparticles, but recently new highly ordered TiO₂ nanotubes (U-tube) has been introduced and applied to various applications due to their one-dimensional charge path way. In the present paper, we described the formation process and physical properties of U-tube then, gave examples of applications in sequence. Firstly, in photocatalysis, U-tube was used with Au/Pt co-catalysts and showed enhanced photogenerated H₂ efficiency compared to bare TiO₂. Secondly, photoelectrochemical performance of U-tube was evaluated with different heat-treatment temperatures. As a further application, two different types of electrical cell (Ti-TiO₂-Pt and Ti-TiO₂-Pt_NP) was configurated to observe memristive behavior of U-tube. Both cells behaved as switching electrodes and follow a memristive movement in the high and low resistance state extremely well with high reproducibility.

• Journal of Powder Materials
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• v.17 no.3
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• pp.216-222
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• 2010

Self-standing $TiO_2$ nanotube arrays were fabricated by potentiostatic anodic oxidation method using pure Ti foil as a working electrode and ethylene glycol solution as electrolytes with small addition of $NH_4F$ and $H_2O$. The influences of anodization temperature and time on the morphology and formation of $TiO_2$ nanotube arrays were investigated. The fabricated $TiO_2$ nanotube arrays were applied as a photoelectrode to dye-sensitized solar cells. Regardless of anodizing temperature and time, the average diameter and wall thickness of $TiO_2$ nanotube show a similar value, whereas the thickness show a different trend with reaction temperature. The thickness of $TiO_2$ nanotube arrays anodized at $20^{\circ}C$ and $30^{\circ}C$ was time-dependent, but on the other hand its at $10^{\circ}C$ are independent of anodization time. The conversion efficiency is low, which is due to a morphology breaking of the $TiO_2$ nanotube arrays in manufacturing process of photoelectrode.

• Korean Journal of Materials Research
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• v.29 no.8
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• pp.491-496
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• 2019

In this study, we prepare pure $WO_3$ inverse opal(IO) film with a thickness of approximately $3{\mu}m$ by electrodeposition, and an ultra-thin $TiO_2$ layer having a thickness of 2 nm is deposited on $WO_3$ IO film by atomic layer deposition. Both sets of photoelectrochemical properties are evaluated after developing dye-sensitized solar cells(DSSCs). In addition, morphological, crystalline and optical properties of the developed films are evaluated through field-emission scanning electron microscopy(FE-SEM), High-resolution transmission electron microscopy(HR-TEM), X-ray diffraction(XRD) and UV/visible/infrared spectrophotometry. In particular, pure $WO_3$ IO based DSSCs show low $V_{OC}$, $J_{SC}$ and fill factor of 0.25 V, $0.89mA/cm^2$ and 18.9 %, achieving an efficiency of 0.04 %, whereas the $TiO_2/WO_3$ IO based DSSCs exhibit $V_{OC}$, $J_{SC}$ and fill factor of 0.57 V, $1.18mA/cm^2$ and 50.1 %, revealing an overall conversion efficiency of 0.34 %, probably attributable to the high dye adsorption and suppressed charge recombination reaction.