• 제목/요약/키워드: seebeck

검색결과 220건 처리시간 0.023초

Computational Simulations of Thermoelectric Transport Properties

  • Ryu, Byungki;Oh, Min-Wook
    • 한국세라믹학회지
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    • 제53권3호
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    • pp.273-281
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    • 2016
  • This review examines computational simulations of thermoelectric properties, such as electrical conductivity, Seebeck coefficient, and thermal conductivity. With increasing computing power and the development of several efficient simulation codes for electronic structure and transport properties calculations, we can evaluate all the thermoelectric properties within the first-principles calculations with the relaxation time approximation. This review presents the basic principles of electrical and thermal transport equations and how they evaluate properties from the first-principles calculations. As a model case, this review presents results on $Bi_2Te_3$ and Si. Even though there is still an unsolved parameter such as the relaxation time, the effectiveness of the computational simulations on the transport properties will provide much help to experimental scientist researching novel thermoelectric materials.

Electronic conductivity of $LaCrO_3$ ceramics prepared by self-propagating high temperature synthesis

  • Soh, Deawha;Korobova, N.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.909-912
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    • 2001
  • Lanthanide orthochromite materials have been widely studied as refractory conducting ceramics because of their electrical conductivity, oxidation resistance and high melting points. In this paper theoretical and experimental analysis about electric conductivity of the SHS prepared ceramics was carried out. The usefulness of the Seebeck-coefficient measurements as a function of P(O$_2$) is emphasized. Electronic conduction was found to be n-type in the lower P(O$_2$) range, and p-type in the higher P(O$_2$) range. The carrier concentrations were calculated as a function of P(O$_2$) and defect structure.

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VGF법을 이용한 $Bi_2Te_{2.55}Se_{0.45}$의 일방향 응고에 관한 연구 (Unidirectional Solidification of $Bi_2Te_{2.55}Se_{0.45}$ using a VGF Method)

  • 김영희;김기수;김수룡;정상진;이윤주;박동선
    • 한국결정학회지
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    • 제14권2호
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    • pp.62-66
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    • 2003
  • VGF법을 사용하여 CuBr₂ dopant가 첨가된 Bi₂Te/sub 2.55/Se/sub 0.45/ 열전재료를 제조하였다. 이 방법을 사용하여 일방향으로 성장된 Bi₂Te/sub 2.55/Se/sub 0.45/ 잉곳의 제조가 가능하였으며 XRD 분석 결과 우선성장 방향이 (0 1 5)면임이 밝혀졌다. 본 실험을 통하여 제조한 열전재료의 Seebeck 계수와 전기전도도를 373∼523 K 범위에서 측정하였다.

열전소자 및 열전냉각장치의 성능에 관한 연구 (A Study on the Performance of Thermoelectric Module and Thermoelectric Cooling System)

  • 유성연;홍정표;심우섭
    • 설비공학논문집
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    • 제16권1호
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    • pp.62-69
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    • 2004
  • Thermoelectric module is a device that can produce cooling in a direct manner using the electrical energy. The purpose of this study is to investigate the performance of thermoelectric module and cooling system equipped with the thermoelectric module. The performance of a thermoelectric module is estimated using two methods; theoretical analysis based on one-dimensional energy equations and experimental tests using heat source, heat sink and brass conduction extenders. For the thermoelectric cooling system, the temperatures in the chamber are recorded and then compared with those of lumped system analysis. The results show that the cooling capacity and COP of the thermoelectric module increases as the temperature difference between hot and cold surface decreases, and there is particular current at which cooling capacity reaches its maximum value. The experimental results for the thermoelectric cooling system are similar to those of lumped system analysis.

Influence of hot deformation and composition on microstructure development of magnesium-stannide alloys

  • Pandel, Divija;Banerjee, Malay K.
    • Advances in materials Research
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    • 제9권3호
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    • pp.171-187
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    • 2020
  • The microstructural evolution of different compositions of Mg-Sn alloys (30%Sn-70%Mg, 40%Sn-60%Mg and 50%Sn-50%Mg) is studied at first to understand the changes observed with change in tin content and deformation conditions. The Mg2Sn phase increases with increase in tin content and a significant substructure development is found in 50%Sn-50%Mg alloy. The above observation led to further deformation studies on Mg2Sn based thermoelectric materials with higher tin percentage. The microstructure in terms of Electron backscatter diffraction (EBSD)measurements is studied in detail followed by the determination of thermoelectric properties i.e., Seebeck coefficient and electrical conductivity for both as cast and extruded Mg(2+x)Sn-Ag alloys. The electrical conductivity of the extruded Mg(2+x)Sn-.3wt%Ag {x =1} alloy was found to be more than its as cast counterpart while the Seebeck coefficient values remained almost the same.

Fe-Si계 재료의 열전성에 미치는 산화의 효과 (Effect of Oxidation ont he Thermoelectricity of Fe-Si based Materials)

  • 송태호;최준영;이홍림;배철훈
    • 한국세라믹학회지
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    • 제33권1호
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    • pp.74-82
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    • 1996
  • Fe-Si based powders prepare by melting the metals in the composition of FeSi2,.Fe0.95Mn0.05Si2 and Fe0.95Co0.05Si0.2 were used as the starting materials together with a commercial FeSi2 powder to study the effect of oxidation on their thermoelectric properties. The powders were heated at 650~80$0^{\circ}C$ in dired air before forming and sintering at 1190 and 120$0^{\circ}C$ in Ar+7%H2. The microstructure and phases of the annealed specimens were observed using the optical microscopty SEM, EDS and XRD. The thermoelectric properties of the specimens were also measured. The temperature at which Seebe다 coefficient showed the maximum value increased with the degree of oxidation. Electrical conductivity showed a tendency to decrease in the oxidized samples regardless of their compositions. Seebeck coefficient of the specimen showed almost the same value even after oxidation which may be explained by the formation of the discontinuous second phases from impurities in the oxidized specimens.

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CdSe 박막반도체의 반송자 밀도 (Carrier Densities of CdSe Thin Films)

  • 김기원
    • 대한전자공학회논문지
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    • 제21권5호
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    • pp.7-10
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    • 1984
  • 일반적으로 단결정반도체시편에서는 그의 자유반송자 밀도값이 측정방법을 달리해도 일정하다. 그러나 CdSe 박막반도체의 자유반송자 밀도간은 측정방법을 달리했을 때 다르게 나타난다. 본 연구에서는 C-V방법, Seebeck 효과 및 a. c. Hall 효과를 통해서 측정한 CdSe 박막반도체의 자유반송자가 1018/㎤∼1024㎤범위의 값을 나타냈다. 이들 값의 차이를 나타내는 원인을 논의하고자 한다.

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LED터널등 모듈의 폐열활용을 위한 열전소자의 발전 성능 분석 (Analysis of the Thermoelectric Devices' Power Generation Performance for Utilizing the Waste Heat of LED Tunnel Lighting Module)

  • 정지영;허인성;이세일;김명호;유영문
    • 조명전기설비학회논문지
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    • 제29권8호
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    • pp.1-6
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    • 2015
  • In this paper, we propose the LED(Light-Emitting-Diode) emergency lighting in a tunnel by using the thermoelectric devices. To achieve high generated power, thermoelectric device should be have high Seebeck coefficient and small contact area. Also, we reveal that a moderate heatsink required for high generated power. From the waste heat of LED tunnel lighting module (25W), the generated power was 0.062W by thermoelectric device, and it could illuminate for 1hour after charge the battery of emergency lighting during about 101hours.