• 제목/요약/키워드: Single Material

검색결과 3,422건 처리시간 0.039초

On-Film Formation of Nanowires for High-efficiency Thermoelectric Devices

  • Ham, Jin-Hee;Shim, Woo-Young;Lee, Seung-Hyun;Voorhees, Peter W.;Lee, Woo-Young
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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    • pp.17-17
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    • 2009
  • We report the invention of a direct growth method termed On-Film Formation of Nanowire (OFF-ON) for making high-quality single-crystal nanowires, i.e. Bi and $Bi_2Te_3$, without the use of conventional templates, catalysts, or starting materials. We have used the OFF-ON technique to grow single crystal semi-metallic Bi and compound semiconductor $Bi_2Te_3$ nanowires from sputtered Bi and BiTe films after thermal annealing, respectively. The mechanism for nanowire growth is stress-induced mass flow along grain boundaries in the polycrystalline films. OFF-ON is a simple but powerful method for growing perfect single-crystal semi-metallic and compound semiconductor nanowires of high aspect ratio with high crystallinity that distinguishes it from other competitive growth approaches that have been developed to date. Our results suggest that Bi and $Bi_2Te_3$ nanowires grown by OFF-ON can be an ideal material system for exploring their unique thermoelectric properties due to their high-quality single crystalline and high conductivity, which have consequence and relevance for high-efficiency thermoelectric devices.

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Hot Wall Epitaxy (HWE) 법에 의한 $CuInTe_2$ 단결정 박막 성장과 가전자대 갈라짐에 대한 광전류연구 (Growth and Characterization of $CuInTe_2$ Single Crystal Thin Films by Hot Wall Epitaxy)

  • 홍광준;박창선
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.156-159
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    • 2003
  • The stochiometric mixture of evaporating materials for the $CuInTe_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CuInTe_2$ mixed crystal was deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were $610^{\circ}C\;and\;450^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about $0.5{\mu}m/h$. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction(DCXD). From the photocurrent spectra, we have found that values of spin orbit coupling ${\Delta}So$ and crystal field splitting ${\Delta}Cr$ ware $0.283{\underline{3}}eV\;and\;0.120{\underline{0}}eV$, respectively.

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일욕 정련 염색에 따른 정련성 및 염색성 연구 (A Study on the Scouring Effect and Dye-ability of Cotton Scoured and Dyed in A Single-bath)

  • 김주혜;권미연;최은경;이숙영
    • 한국염색가공학회지
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    • 제19권3호
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    • pp.1-5
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    • 2007
  • The advantage of enzyme scouring over alkali scouring is that the enzymatic process can be carried in a neutral pH, resulting in less damage on the fibers and a drastic reduction of wastewater. Since the pH of scouring bath is neutral, dyeing can be carried in the same bath. Four different types of scouring and dyeing in a single-bath were performed in this work: continuous scouring and dyeing in one-bath I and II, simultaneous scouring and dyeing in one-bath I and II. The difference between process I and II is the existence of an after-treatment process in the scouring. Dyeing was performed with three major colors(red, blue, yellow) and black to investigate the dye-ability. The absorbency of scoured and dyed fabrics was measured using gravimetric absorbency testing system. The fabric weight loss was measured after the treatment. Although the color depth for the three major colored fabrics treated in a single-bath was lower than the fabric scoured and dyed separately, the fabrics dyed with black did not show much difference. In addition, the absorbency of fabric treated in a single-bath was higher than the fabric treated separately.

Hexaphenylbenzene $C_6(C_6H_5)_6$

  • Kim Young-Sang;Ko Jaejung;Kang Sang Ook;Han Won-Sik;Jeong Jae-Ho;Suh Il-Hwan
    • 한국결정학회지
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    • 제16권1호
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    • pp.1-5
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    • 2005
  • The structure of the title compound has been determined by single-crystal X-ray diffraction work. The crystals are orthorhombic, space group $Pna2_1$ with a=11.095(3), b=21.834(7), c=12.574(4) $\AA$, and R1=0.0667. The average carbon bond length in aromaticity In the molecule is 1.386(1) $\AA$ and the average single bond length linking the central benEene ring and peripheral phenyl rings is 1.491(3) $\AA$. The average dihedral angle between the central benzene ring and each of six peripheral phenyl rings is $67.1(1)^{\circ}$ and the average dihedral angle between neighboring two phenyl rings is $55.0(1)^{\circ}$. Thus the molecule adopts a quasi-propeller configuration with approximate six-fold rotation symmetry.

Flux법에 의한 YBa2Cu3Ox 단결정 육성에 관한 연구 (Single Crystal Growth of YBa2Cu3Ox by Flux Method)

  • 서현석;설용건
    • 한국세라믹학회지
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    • 제27권1호
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    • pp.27-34
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    • 1990
  • Single crystals of YBa2Cu3Ox superconductor were grown by means of the flux method. The effectof starting material, cooling rate, melting time, and melting temperjature were evaluated as influencing paraemters. The larger single crystals of YBa2Cu3Ox were obtained with Y2BaCuOy powder as a starting material than with YBa2Cu3Ox powder. The optimum range of synthetic condition for single crystal growth was as follows ; 2-5$^{\circ}C$/hour of cooling rate, 2-5 hour of melting time and melting temperature at 106$0^{\circ}C$. The obtained size of single crystal was 2mm in average and the largest one was 5mm in maximum.

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α-In2S3:Co2+ 단결정의 광학적 특성에 관한 연구 (Optical Properties of α-In2S3:Co2+ Single Crystal)

  • 박광호;현승철;정진;오석균
    • 한국전기전자재료학회논문지
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    • 제21권12호
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    • pp.1057-1062
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    • 2008
  • The ${\alpha}-In_2S_3:Co^{2+}$ single crystal with a good quality and stabilized property were gained successfully by the CTR(Chemical Transport Reaction)method. XRD analysis showed that the grown single crystals were cubic structure. The optical absorption spectra of ${\alpha}-In_2S_3:Co^{2+}$ single crystal showed impurity absorption peaks due to cobalt impurity. These impurity absorption pesks were assigned to the ligand transition between the split energy levels of $Co^{2+}$ ions sited in $T_d$ symmetry of these semiconductor host lattice.

ZnO 바리스터의 단입계면 분석을 위한 마이크로 전극 제작과 전기적 특성 해석 (The Fabrication of Micro-electrodes to Analyze the Single-grainboundary of ZnO Varistors and the Analysis of Electrical Properties)

  • 소순진;임근영;박춘배
    • 한국전기전자재료학회논문지
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    • 제18권3호
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    • pp.231-236
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    • 2005
  • To investigate the electrical properties at the single grainboundary of ZnO varistors, micro-electrodes were fabricated on the surface which was polished and thermally etched. Our micro-electrode had 2000 $\AA$ silicon nitride layer between micro-electrode and ZnO surface. This layer was deposited by PECVD and etched by RIE after photoresistor pattering process using by mask 1. The metal patterning of micro-electrodes used lift-off method. We found that the breakdown voltage of single grainboundary is about 3.5∼4.2 V at 0.1 mA on I-V curves. Also, capacitance-voltage measurement at single grainboundary gave several parameters( $N_{d}$, $N_{t}$, $\Phi$$_{b}$, t) which were related with grainboundary.ary.

Si(001)/NiO(300$\AA$)/NiFe계 휘스톤 브리지형 자기저항소자 (Wheastone-bridge type MR sensors of Si(001)/NiO(300 $\AA$)/NiFe bilayer system)

  • 이원재;민복기;송재성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.1050-1053
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    • 2001
  • There is great interest in developing magnetoresistance(MR) sensor, using ferromagnetic, electrically non-magnetic conducting and antiferromagnetic films, especially for the use in weak magnetic fields. Here, we report single and Wheatstone-bridge type of MR sensors made in Si(001)/HiO(300$\AA$)/NiFe bilayers. Angular dependence of MR profiles was measured in Si(001)/NiO(300$\AA$)/NiFe(450$\AA$) films as a function of an angle between current and applied field direction, also, linearity was determined. AMR characteristics of single MR sensors was well explained with single domain model. Good linearity in 45$^{\circ}$Wheatstone-bridge type of MR sensors consisting of 4 single MR sensors made in Si(001)/NiO(300$\AA$)/NiFe(450$\AA$) was shown in the range of about $\pm$50 Oe.

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Hot Wall Epitaxy (HWE)에 의한 성장된 $ZnIn_2S_4$ 단결정 박막의 광전류 특성 (Opto-electric Properties of $ZnIn_2S_4$ single crystal thin film Grown by Hot Wall Epitaxy method)

  • 홍광준;이상열
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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    • pp.71-72
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    • 2006
  • The stochiometric mixture of evaporating materials for the $ZnIn_2S_4$ single crystal thin film was prepared from horizontal furnace. To obtain the $ZnIn_2S_4$ single crystal thin film. $ZnIn_2S_4$ mixed crystal was deposited on throughly etched semi-insulating GaAs(100). In the Hot Wall Epitaxy(HWE) system. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $ZnIn_2S_4$ single crystal thin film, we have found that the values of spin orbit splitting ${\Delta}So$ and the crystal field splitting ${\Delta}Cr$ were 0.0148 eV and 0.1678 eV at $10_{\circ}K$, respectively.

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IPS 모드를 이용한 반투과형 액정 디스플레이 (Transflective Liquid Crystal Display using In-Plane Switching Mode)

  • 송제훈;임영진;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.153-156
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    • 2004
  • We have studied electro-optic characteristics of transflective liquid crystal display (LCD) using in-plane switching mode. Unlike previous transflective LCD using a dual gap structure and multi driving circuit, this transflective LCD has a single gap structure and a single driving circuit. In the voltage on state, the electric field is applied horizontally to the LC directors, and then homogeneously aligned LC directors at initial state is rotated to with the electric field. But the twist angle of the LC directors in reflective area is lower than transmissive area. As a result, it is possible to design the transflective LCD with a single gap and a single driving circuit. The transflective display associated with this LC cell exhibits a wide viewing angle in both reflective and transmissive areas.

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