• 제목/요약/키워드: Solid-State Synthesis

검색결과 357건 처리시간 0.032초

Low Temperature Synthesis of TiO2 Films for Application to Dye-sensitized Solar Cells

  • 위진성;최은창;서영호;홍병유
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.475-475
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    • 2014
  • Dye sensitized solar cells (DSSCs) are regarded as potential inexpensive alternatives to conventional solid-state devices. The flexible version, employing conductive-plastic-film substrates, is appealing for commercialization of DSSCs because it not only reduces the weight and cost of the device but also extends their applications. However, the need for high temperature does not permit the use of plastic-film substrate. So, development of low-temperature methods is therefore realization of flexible DSSCs. In this work, the electrophoretic deposition combined with hydrothermal treatment was employed to prepare nanocrystalline $TiO_2$ thin film at low temperature. We confirmed the prepared $TiO_2$ thin films with different voltages and deposition times in the electrophoretic deposition process. Properties of the $TiO_2$ films were investigated by various analysis method such as X-ray diffraction, field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometer.

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Ca1-xSrxS:Mn 형광체의 합성과 광 특성 (Synthesis and Optical Properties of Ca1-xSrxS:Mn Phosphors)

  • 성혜진;허영덕
    • 한국재료학회지
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    • 제17권3호
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    • pp.137-141
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    • 2007
  • A series of $Ca_{1-x}Sr_{x}S:Mn$ phosphors were synthesized by solid-state reactions. The emission peaks of $Ca_{1-x}Sr_{x}S:Mn$ is blue shifted front 605 to 570 nm with increasing Sr content. Since $Ca_{1-x}Sr_{x}S:Mn$. Mn phosphors exhibit strong absorption in region of 254 nm, the emission wavelength of a fluorescent lamp, these phosphors can be used as wavelength tunable emitting phosphors from reddish orange to yellow. We investigated the optical and structural properties of $Ca_{1-x}Sr_{x}S:Mn$ phosphors.

Synthesis of $M(WO_4)$:Eu (M : Group 1 or 2) for LED and its Luminescent Properties

  • Park, Seung-Hyok;Kim, Chang-Hae;Park, Hee-Dong;Kim, You-Hyuk
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.838-841
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    • 2002
  • $M(WO_4)$:Eu phosphor as a red emitting phosphor for LED was prepared by solid state method. Tungstate phosphors were exited at long wavelength ultra violet region. In special, the emission of Eu-doped $M(WO_4)$:Eu phosphor under the excitation of 410nm appeared at 613nm. $M(WO_4)$:Eu phosphors with M : Group 1 had a higher excitation intensity than those of the phosphors with M: Group 2 at long-wavelength UV.

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Synthesis of an oxynitride-based green phosphor $Ba_3Si_6O_{12}N_2:Eu^{2+}$ via an aqueous-solution process, using propylene-glycol-modified silane

  • Yasushita, Chihiro;Kato, Hideki;Kakihana, Masato
    • Journal of Information Display
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    • 제13권3호
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    • pp.107-111
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    • 2012
  • An almost pure phase of $Ba_3Si_6O_{12}N_2$ doped with $Eu^{2+}$ was successfully synthesized through the ammonia nitridation of an oxide precursor prepared through an aqueous-solution method, using propylene- glycol-modified silane. The emission peak intensity of the obtained $Ba_3Si_6O_{12}N_2:Eu^{2+}$ was -2.2 times higher than that of the sample prepared through a solid-state reaction method.

Synthesis of Novel Morpholine Appended Crystal violet lactone Derivatives and an Investigation of Their Thermochromic Behavior

  • Kim, Myeong Jin;Muthukumar, Palanisamy;Angupillai, Satheshkumar;Son, Young-A
    • 한국염색가공학회지
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    • 제30권1호
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    • pp.1-8
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    • 2018
  • In the present study, three morpholine substituted crystal violet lactone (CVL) have been synthesized to monitor the thermochromic property. This work is explaining the role of substituent on the lactone ring. The methyl substituents induced greater chromic effects than the chloro substituents. Furthermore, the three-component mixtures that contained CVL, bisphenol-A, and methyl stearate were used to analyse the thermochromic effect of the CVLs as bulk samples with various temperature. The thermochromic properties of the CVLs were evaluated using solid-state UV-Vis and FT-IR spectroscopic techniques. Finally, one of the synthesized CVL has been successfully converted into the form of a test paper similar to pH paper for use as thermal indicators.

SOFC 용 LSCF/CGO 공기극의 제조 및 특성연구 (Synthesis and Characterization of LSCF/CGO Composite Used as SOFC Cathode Materials)

  • 박재량;임탁형;이승복;박석주;신동렬;송락현
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.184-186
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    • 2009
  • Composites of LSCF($La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta}$ and CGO(gadolinium doped ceria) is an efficient candidate cathode material with CGO electrolytes. In this study, LSCF with exact perovskite structure was synthesized by using solid state reaction(SSR) method. The optimized temperature to synthesize $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta}$ with rhombohedral structure. was $1100^{\circ}C$. The polarization resistance of the LSCF/CGO(50:50 wt.%) was smaller than those of other composite cathodes. The analysis of the EIS data of LSCF/CGO suggests that the diffusion and adsorption-desorption of oxygen can be the key process in the cathodic reaction of SOFC using LSCF/CGO as cathode material.

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Photoluminescence of YVO4:Eu3+ Prepared by Li2CO3 Addition

  • Moon, Seong-Jun;Jeong, Hyun-Gon;Kwak, Jong-Ho;Sohn, Kee-Sun
    • 한국세라믹학회지
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    • 제45권11호
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    • pp.658-661
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    • 2008
  • Deep red color emitting $YVO_4:Eu^{3+}$ phosphors were investigated in an attempt to achieve promising performances in cold cathode fluorescent lamp (CCFL) applications. For this purpose, several additives such as LiF, $Li_2CO_3$ and $HBO_3$ were introduced in the processing. While two of the additives were ineffective, the inclusion of $LiCO_3$ during the solid state synthesis of $YVO_4:Eu^{3+}$ phosphors was proven to enhance photoluminescent intensity and the color chromaticity. Unlike the commercially available $YVO_4:Eu^{3+}$ red phosphor for use in PDP applications, pure $YVO_4:Eu^{3+}$ excluding phosphorous was shown to be favorable for CCFL applications, improving color chromaticity at 254nm excitations.

Synthesis of Fe-TiB2 Nanocomposite by a combination of mechanical activation and heat treatment

  • ;;김지순;강태훈;김진천;권영순
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2012년도 춘계학술발표대회
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    • pp.91.2-91.2
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    • 2012
  • The TiB2-reinforced iron matrix nanocomposite (Fe-TiB2) was in-situ fabricated from titanium hydride (TiH2) and iron boride (FeB) powders by a simple and cost-effective process that combines the mechanical activation (MA) and a subsequent heat treatment (HT). Effect of milling factors and synthesized temperatures on the formation of the nanocomposite were presented and discussed. A differential thermal analyser (DSC-TG) was employed for examination of thermal behavior of MAed powders. Phases of the nanocomposite were confirmed by X-ray diffraction analysis (XRD). The morphologies and microstructure of nanocomposite were investigated by field emission-scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS). Phase composition and distribution were analyzed by electron probe X-ray microanalysis (EPMA). Results showed that TiB2 particles formed in nanoscale were uniformly distributed in alloyed Fe matrix.

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Polarization Behavior of Li4Ti5O12 Negative Electrode for Lithiumion Batteries

  • Ryu, Ji-Heon
    • Journal of Electrochemical Science and Technology
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    • 제2권3호
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    • pp.136-142
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    • 2011
  • $Li_4Ti_5O_{12}$ is prepared through a solid-state reaction between $Li_2CO_3$ and anatase $TiO_2$ for applications in lithium-ion batteries. The rate capability is measured and the electrode polarization is analyzed through the galvanostatic intermittent titration technique (GITT). The rate characteristics and electrode polarization are highly sensitive to the amount of carbon loading. Polarization of the $Li_4Ti_5O_{12}$ electrode continuously increases as the reaction proceeds in both the charge and discharge processes. This relation indicates that both electron conduction and lithium diffusion are significant factors in the polarization of the electrode. The transition metal (Cu, Ni, Fe) ion added during the synthesis of $Li_4Ti_5O_{12}$ for improving the electrical conductivity also greatly enhances the rate capability.

Synthesis of $Ba_2SiS_4:Eu^{2+}$ Blue-Green Phosphor Prepared by Spray Drying Method Using Water Soluble Silicon Compound

  • Tezuka, Satoko;Suzuki, Yoshihito;Petrykin, Valery;Kakihana, Masato
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.243-245
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    • 2009
  • The single phase $Ba_2SiS_4$ doped with $Eu^{2+}$ was successfully synthesized by direct sulfurization of an oxide precursor prepared by a spray drying method using a novel water soluble silicon compound, which remains soluble in a given aqueous solution. The intensity of the emission peak of thus obtained $Ba_2SiS_4:Eu^{2+}$ was 1.75 times larger than that of a sample prepared by a solid state reaction method, and it approached 106% compared to one of the best commercially available YAG:$Ce^{3+}$ phosphor.

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