• Title/Summary/Keyword: Bi-Sb-Te

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Characterization of amorphous Sb-Bi-Te thin films as a function of Bi concentration (Bi 농도에 따른 비정질 Sb-Bi-Te 박막의 특성)

  • ;D. Mangalaraj
    • Journal of the Korean Vacuum Society
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    • v.11 no.1
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    • pp.28-34
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    • 2002

  • Thin films of $Sb_{2-x}Bi_xTe_3$ (x = 0.0, 0.5, and 1.0) are grown by vacuum evaporation. XRD analysis shows the amorphous nature of the films, and the composition studies confirm the stoichiometry of the films. Microstructural parameters of the films have been calculated and used to explain the electrical and optical properties of the films. It is observed that the carrier type has changed from p- to n-type at higher concentration (x = 1.0) of Bi. The resistivity of the films decreases rapidly with the increase of Bi concentration. However, the refractive index and optical band gap of the films increase with the Bi concentration.

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P-type and N-type $Bi_2Te_3/PbTe$ Functional Gradient Materials for Thermoelectric Power Generation

  • Lee, Kwang-Yong;Oh, Tae-Sung
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1223-1224
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    • 2006

  • The p-type $(Bi_{0.2}Sb_{0.8})_2Te_3/(Pb_{0.7}Sn_{0.3})$Te functional gradient material (FGM) was fabricated by hot-pressing the mechanically alloyed $(Bi_{0.2}Sb_{0.8})_2Te_3$ and the 0.5 at% $Na_2Te-doped$ $(Pb_{0.7}Sn_{0.3})Te$ powders. Also, the n-type $Bi_2(Te_{0.9}Se_{0.1})_3/PbTe$ FGM was processed by hot-pressing the mechanically alloyed $Bi_2(Te_{0.9}Se_{0.1})_3$ and the 0.3 wt% Bi-doped PbTe powders. With ${\Delta}T$ larger than $300^{\circ}C$, the p-type $(Bi_{0.2}Sb_{0.8})_2Te_3/(Pb_{0.7}Sn_{0.3})Te$ FGM exhibited larger thermoelectric output power than those of the $(Bi_{0.2}Sb_{0.8})_2Te_3$ and the 0.5 at% $Na_2Te-doped$ $(Pb_{0.7}Sn_{0.3})Te$ alloys. For the n-type $Bi_2(Te_{0.9}Se_{0.1})_3/PbTe$ FGM, the thermoelectric output power superior to those of the $Bi_2(Te_{0.9}Se_{0.1})_3$ and the 0.3 wt% Bi-doped PbTe was predicted at ${\Delta}T$ larger than $300^{\circ}C$.

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The Electric and Thermal Properties of Spark Plasma Sintered Bi0.5Sb1.5Te3 (방전플라즈마 소결된 Bi0.5Sb1.5Te3의 열/전기적 특성)

  • Lee, Gil-Geun;Choi, Young-Hoon;Ha, Gook-Hyun
    • Journal of Powder Materials
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    • v.19 no.4
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    • pp.285-290
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    • 2012

  • The present study was focused on the analysis of the electric and thermal properties of spark plasma sintered $Bi_{0.5}Sb_{1.5}Te_3$ thermoelectric material. The crystal structure, microstructure, electric and thermal properties of the sintered body were evaluated by measuring XRD, SEM, electric resistivity, Hall effect and thermal conductivity. The $Bi_{0.5}Sb_{1.5}Te_3$ sintered body showed anisotropic crystal structure. The c-axis of the $Bi_{0.5}Sb_{1.5}Te_3$ crystal aligned in a parallel direction with applied pressure during spark plasma sintering. The degree of the crystal alignment increased with increasing sintering temperature and sintering time. The electric resistivity and thermal conductivity of the $Bi_{0.5}Sb_{1.5}Te_3$ sintered body showed anisotropic characteristics result from crystal alignment.

  • https://doi.org/10.4150/KPMI.2012.19.4.285 인용 PDF KSCI

Performance of $(Bi, Sb)_2 (Te, Se)_3$ Thin Film Thermoelectric Modules ($(Bi, Sb)_2 (Te, Se)_3$ 열전박막소자의 작동특성)

  • 김일호;이동의
    • Journal of the Korean Vacuum Society
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    • v.3 no.3
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    • pp.309-315
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    • 1994

  • 순간증착법으로 p형(Bi0.5Sb1.5Te3)과 n형(Bi2Te24Se0.6)열전박막을 제조하여 상온에서 Seebeck 계 수, 전기전도도 및 열전성능지수를 측정하였다. 또한 금속재 mask를 이용하여 다중접점 박막형 열전소 자를 제작하고 그 작동특성을 조사하였다. 이때 소자의 고온부와 저온부의 온도를 직접측정하기 위하여 copper/constantan 박막을 접점부에 증착하여 열전쌍이 되게 하였다. p/n 접점이 5쌍이 소자의 경우 Peltier 효과에 의해 생성된 최대온도차는 22K이었다.

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Thermoelectric Properties of p-type 25% $Bi_{2}Te_{3}+75%Sb_{2}Te_{3}$ Materials Prepared by Rapid Solidification Process and Hot Pressing (급속응고기술에 의한 p-type 25% $Bi_{2}Te_{3}+75% Sb_{2}Te_{3}$ 열간압축제의 열전특성)

  • 김익수
    • Journal of Powder Materials
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    • v.3 no.4
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    • pp.246-252
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    • 1996

  • $Bi_{2}Te_{3}-Sb_{2}Te_{3}$, $Bi_{2}Te_{3}-Bi_{2}Se_{3}$ solid solutions are of great interest as materials for thermoelectric energy conversion. One of the key technologies to ensure the efficiency of thermoelectric device is to obtain chemically homogeneous solid solutions. In this work, the new process with rapid solidification followed by hot pressing was investigated to produce homogeneous thermoelectric materials. Characteristics of the materials were examined with XRD, SEM, EPMA-line scan and bending test. Property variations of the materials were investigated as a function of variables, such as excess Te quantity and hot pressing temperature. Quenched ribbons are very brittle and consisted of homogeneous $Bi_{2}Te_{3}$, $Sb_{2}Te_{3}$ solid solutions. When the process parameters were optimized, the maximum figure of merit was 3.073$\times$$10^{-3}K^{-4}$. The bending strength of the material, hot pressed at 45$0^{\circ}C$, was 5.87 kgf/${mm}^2$.

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