• Title/Summary/Keyword: Tellurium

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Synthesis of Aligned Te Nanoribbons by Lithographically Patterned Nanowire Electrodeposition Technique (리쏘그라피 패턴 전해증착법에 의해 얼라인된 Te 나노리본 합성)

  • Jeong, Hyeon-Seong;Myung, Nosang V.
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.104-105
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    • 2014
  • 마이크로 패턴된 Au 전극사이에 얼라인된 Tellurium (Te) 나노리본들이 의도한 모양과 배열방식을 가지고 리쏘그래피 패턴 전해증착 (Lithographically patterned nanowier electrodepositon, LPNE) 방법에 의해 4인치 Si wafer 배치로 합성되었다. 합성된 Te 나노리본은 수 센티미터의 길이를 가지고, 그 두께와 폭 역시 작업 전극으로 사용되는 Si wafer위에 증착된 Ni의 두께와 전해증착 시간에 의해 쉽게 제어될 수 있다. $3{\mu}m$의 간격을 갖는 Au 전극 사이에 얼라인된 두께 ~100nm의 Te 나노리본들은 전해증착에 의해 그 폭이 제어되었고, 각각의 다른 폭을 갖는 증착된 하나의 Te 나노리본들의 IV 및 FET 측정을 통하여 나노리본 폭의 변화에 따른 전기적 특성 (비저항, FET 이동도 및 FET 캐리어 농도)이 평가되었다.

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Thermoelectric Properties of CoSb3-yTey Prepared by Encapsulated Induction Melting (밀폐유도용해로 제조한 CoSb3-yTey의 열전특성)

  • Kim, Mi-Jung;Shim, Woo-Seop;Ur, Soon-Chul;Kim, Il-Ho
    • Korean Journal of Materials Research
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    • v.16 no.7
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    • pp.412-415
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    • 2006
  • Te-doped $CoSb_3$ was prepared by the encapsulated induction melting, and its doping effects on the thermoelectric properties were investigated. Single phase ${\delta}-CoSb_3$ was successfully obtained by the subsequent annealing at 773 K for 24 hrs. Tellurium atoms acted as electron donors by substituting antimony atoms. Thermoelectric properties were remarkably improved by the appropriate doping. Dimensionless figure of merit was obtained to be 0.83 at 700K for the $CoSb_{2.8}Te_{0.2}$ specimen.

High-Efficiency ITO/Se Solar Cells (Se 태양전지(太陽電池)의 고효율화(高效率化)에 관한 연구(硏究))

  • Kim, Tae-Seoung
    • Solar Energy
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    • v.7 no.2
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    • pp.7-13
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    • 1987
  • Indium-Tin-Oxide (ITO)/Selenium heterojunction solar cells which fabricated by vacuum deposition technique and annealing process has been investigated. Prior to the Selenium deposition, a thin tellurium layer (about $10{\AA}$) was deposited onto the ITO layers to provide a sufficient mechanical bond between the Oxide and Selenium layers. The amorphous Selenium layer was deposited onto the Te-ITO layers, and then the crystallization of the amorphous Selenium was carried out using a hot plate at about $180^{\circ}C$ for 4 min. Efficient Selenium solar cells with conversion efficiency as high as 4.52% under AM1 condition has been fabricated in polycrystalline Selenium layer ($6{\mu}m$). The optimum data in manufacturing Se solar cell was listed in table.

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A Study on Ni Base Anti-galling alloy with Finely Dispersed Precipitates (석출상이 분산제어된 내마모성 니켈기 윤활합금 연구)

  • Kim, Young-Kyu;Kim, Kyung-Tak
    • Journal of Korea Foundry Society
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    • v.26 no.4
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    • pp.191-196
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    • 2006
  • The effects of Bi and Te on the anti-galling behaviors of Ni base alloy were investigated by SEM, galling test and wear test. Anti-galling characteristics depended on the structure of matrix and distribution of Bi-rich phase which was precipitated at grain boundary. The addition of 5 wt% Bi markably enhanced anti-galling properties. The addition of Te caused Bi-rich precipitates to disperse finely and casting structure to form equiaxed type. From the above tests, the concentration of 5 wt% Bi and 1 wt% Te was selected to optimize in this alloy.

The electrical and optical properties of Se-As-Te photoconductor and its application (Se-As-Te 광도전막의 특성 및 응용)

  • Park, Sang-Jun;Oh, Sang-Kwang;Choi, Ku-Man;Kim, Ki-Wan
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.501-504
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    • 1987
  • The photoconductor is made of evaporated amorphous selenium as the base material, doped with arsenic and tellurium to prevent crystallization and to increase the red sensitivity of the amorphous selenium. The four-layered photoconductor of Se-As-Te has good photosensitivity(r=0.9) and high dark resistivity($P_d=10^{12}{\Omega}{\cdot}cm$). therefore, this four-layered photoconductor can be used for the target of color image pick-up tube.

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Experimental fabrication and analysis of thermoelectric devices (복합재료에 의한 열전변환 냉각소자의 개발에 관한 연구)

  • 성만영;송대식;배원일
    • Electrical & Electronic Materials
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    • v.9 no.1
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    • pp.67-75
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    • 1996
  • This paper has presented the characteristics of thermoelectric devices and the plots of thermoelectric cooling and heating as a function of currents for different temperatures. The maximum cooling and heating(.DELTA.T) for (BiSb)$\_$2/Te$\_$3/ and Bi$\_$2/(TeSe)$\_$3/ as a function of currents is about 75.deg. C, A solderable ceramic insulated thermoelectric module. Each module contains 31 thermoelectric devices. Thermoelectric material is a quaternary alloy of bismuth, tellurium, selenium, and antimony with small amounts of suitable dopants, carefully processed to produce an oriented polycrystalline ingot with superior anisotropic thermoelectric properties. Metallized ceramic plates afford maximum electrical insulation and thermal conduction. Operating temperature range is from -156.deg. C to +104.deg. C. The amount of Peltier cooling is directly proportional to the current through the sample, and the temperature gradient at the thermoelectric materials junctions will depend on the system geometry.

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Geochemistry of a Te-bearing Au-Ag mineralization of the Yuryang mine: Fluid inclusion and stable isotope study

  • Heo, Chul-Ho;Choi, Seon-Gyu;Pak, Sang-Joon;Choi, Sang-Hoon;Yun, Seong-Taek
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.178-179
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    • 2003
  • Mesothermal, tellurium-bearing gold-silver vein mineralization of the Yuryang mine was formed in mineralogically complex quartz-sulfide veins that filled the fault fractures in Precambrian gneiss within Gyeonggi Massif. Ore grades average 179 g/ton gold with a gold/silver ratio of 1.5 : 1. Ore mineralization was deposited in single stage. Major ore mineralization can be divided into two mineralization phases with increasing paragenetic time: Fe-sulfide and base-metal mineralization phase $\rightarrow$ telluride mineralization phase. (omitted)

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Photoemission study f valence stated in Eu chalcogenides

  • Hoon Koh;Park, Won-Go;Oh, S.J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.166-166
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    • 2000
  • We studied electronic structure of magnetic semiconductors EuO, EuS, and EuTe. The photoemission spectra show localized Eu 4f states and broad anion p bands. As the size of anion increases from oxygen to tellurium, anion p band width increases and eventually overlaps Eu 4f states. Hence in EuO and EuS, Eu 4f states are the highest occupied stated lying above anion p band, while Te 5p band spreads widely over Eu 4f states to become valence band maximum in EuTe. It was also observed that Eu 4f states have width of 0.7eV and dispersion of 0.2eV in EuS by angle resolved photoemission spectroscopy. The width of the 4f spectra mainly originates from atomic multiplets, but the much larger dispersion than that of Eu metal is due to p-f mixing.

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Synthesis of Tellurium Sorption Complexes in Fully Dehydrated and Fully Ca2+-exchanged Zeolites A and X and their Single-crystal Structures

  • Lim, Woo-Taik;Park, Jong-Sam;Lee, Sang-Hoon;Jung, Ki-Jin;Heo, Nam-Ho
    • Bulletin of the Korean Chemical Society
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    • v.30 no.6
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    • pp.1274-1284
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    • 2009
  • Single crystals of fully dehydrated and fully $Ca^{2+}$-exchanged zeolites A (|$Ca_6$|[$Si_{12}Al_{12}O_{48}$]-LTA) and X (|$Ca_{46}$| [$Si_{100}Al_{92}O_{384}$]-FAU) were brought into contact with Te in fine pyrex capillaries at 623 K and 673 K, respectively, for 5 days. Crystal structures of Te-sorbed $Ca^{2+}$-exchanged zeolites A and X have been determined by single-crystal X-ray diffraction techniques at 294 K in the cubic space group Pm$\overline{3}$ m (a = 12.288(2) $\AA$) and Fd $\overline{3}$ (a = 25.012(1) $\AA$), respectively. The crystal structures of pale red-brown |$Ca_6Te_3$|[$Si_{12}Al_{12}O_{48}$]-LTA and black coloured |$Ca_{46}Te_8$| [$Si_{100}Al_{92}O_{384}$]-FAU have been refined to the final error indices of $R_1/wR_2\;=\;0.1096/0.2768\;and\;R_1/wR_2$ = 0.1054/ 0.2979 with 204 and 282 reflections for which $F_o\;>\;4{\sigma}(F_o)$, respectively. In the structure of |Ca6Te3|[$Si_{12}Al_{12}O_{48}$]- LTA, 6 $Ca^{2+}$ ions per unit cell were found at one crystallographic positions, on 3-fold axes equipoints of opposite 6-rings. In |$Ca_{46}Te_8$|[$Si_{100}Al_{92}O_{384}$]-FAU, 46 $Ca^{2+}$ ions per unit cell were found at four crystallographically distinct positions: 3 $Ca^{2+}$ ions at Ca(1) fill the 16 equivalent positions of site I, 21 $Ca^{2+}$ ions at Ca(2) fill the 32 equivalent positions of site I’, 10 and 12 $Ca^{2+}$ ions at Ca(3) and Ca(4), respectively, fill the 32 equivalent positions of site II. The Te clusters are stabilized by interaction with cations and framework oxygen. In sodalite units, Te-Te distances of 2.86(10) and 2.69(4) $\AA$ in zeolites A and X, respectively exhibited strong covalent properties due to their interaction with $Ca^{2+}$ ions. On the other hand, in large cavity and supercage, those of 2.99(3) and 2.76(11) $\AA$ in zeolites A and X, respectively, showed ionic properties because alternative ionic interaction was formed through framework oxygen at one end and $Ca^{2+}$ cations at the other end.