• 제목/요약/키워드: Semiconductor nanowires

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Comparison of Ga-doped and Ag-doped ZnO Nanowire Gas-sensor Sensitivity and Selectivity

  • Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • 제16권6호
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    • pp.334-337
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    • 2015
  • Pure ZnO, ZnO nanowires doped with 3 wt.% Ga (3GZO) and doped with 3 wt.% Ag (3SZO) were grown by a hot-walled pulse laser deposition (HW-PLD) technique. The optical and chemical properties of Ga and Ag doped nanowires was analyzed. Nanowires were determined to be under 200 nm in diameter and several μm in length. Change of significant resistance was observed and the gas detection sensitivities of ZnO, 3GZO and 3SZO nanawires were compared. The sensitivities of ZnO, 3GZO, and 3SZO nanowire sensors were measured at 300℃ for 1 ppm of ethanol gas at 97%, 48%, and 203%, respectively.

Nanogap Array Fabrication Using Doubly Clamped Freestanding Silicon Nanowires and Angle Evaporations

  • Yu, Han-Young;Ah, Chil-Seong;Baek, In-Bok;Kim, An-Soon;Yang, Jong-Heon;Ahn, Chang-Guen;Park, Chan-Woo;Kim, Byung-Hoon
    • ETRI Journal
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    • 제31권4호
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    • pp.351-356
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    • 2009
  • We present a simple semiconductor process to fabricate nanogap arrays for application in molecular electronics and nano-bio electronics using a combination of freestanding silicon nanowires and angle evaporation. The gap distance is modulated using the height of the silicon dioxide, the width of the Si nanowires, and the evaporation angle. In addition, we fabricate and apply the nanogap arrays in single-electron transistors using DNA-linked Au nanoparticles for the detection of DNA hybridization.

Fabrication, Structure and Gas Sensing Properties of Pt-functionalized ZnS Nanowires

  • Kim, Soohyun;Park, Sunghoon;Jung, Jihwan;Lee, Chongmu
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.315.2-315.2
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    • 2014
  • Pt-functionalized ZnS nanowires were synthesized on Au-deposited c-plane sapphire substrates by thermal evaporation of ZnS powders followed by wet Pt coating and annealing. The $NO_2$ gas sensing properties of multiple-networked Pt-functionalized ZnS nanowire sensors were examined. Scanning electron microscopy showed the nanowires with diameters of 20-80 nm. Transmission electron microscopy and X-ray diffraction showed that the nanowires were wurtzite-structured ZnS single crystals. The Pt-functionalized ZnS nanowire sensors showed enhanced sensing performance to $NO_2$ gas at $150^{\circ}C$ compared to pristine ZnS nanowire sensors. Pristine and Pt-functionalized ZnS nanowire sensors showed responses of 140-211% and 207-488%, respectively, to 1-5 ppm $NO_2$, which are better than or comparable to those of many oxide semiconductor sensors. In addition, the underlying mechanism of the enhancement of the sensing properties of ZnS nanowires by Pt functionalization is discussed.

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Optically transparent and electrically conductive indium-tin-oxide nanowires for transparent photodetectors

  • Kim, Hyunki;Park, Wanghee;Ban, Dongkyun;Kim, Hong-Sik;Patel, Malkeshkumar;Yadav, Pankaj;Kim, Joondong
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.390.2-390.2
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    • 2016
  • Single crystalline indium-tin-oxide (ITO) nanowires (NWs) were grown by sputtering method. A thin Ni film of 5 nm was coated before ITO sputtering. Thermal treatment forms Ni nanoparticles, which act as templates to diffuse Ni into the sputtered ITO layer to grow single crystalline ITO NWs. Highly optical transparent photoelectric devices were realized by using a transparent metal-oxide semiconductor heterojunction by combining of p-type NiO and n-type ZnO. A functional template of ITO nanowires was applied to this transparent heterojunction device to enlarge the light-reactive surface. The ITO NWs/n-ZnO/p-NiO heterojunction device provided a significant high rectification ratio of 275 with a considerably low reverse saturation current of 0.2 nA. The optical transparency was about 80% for visible wavelengths, however showed an excellent blocking UV light. The nanostructured transparent heterojunction devices were applied for UV photodetectors to show ultra fast photoresponses with a rise time of 8.3 mS and a fall time of 20 ms, respectively. We suggest this transparent and super-performing UV responser can practically applied in transparent electronics and smart window applications.

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ITO 나노와이어 기반의 투명 산화물 반도체 광전소자 (ITO Nanowires-embedded Transparent Metal-oxide Semiconductor Photoelectric Devices)

  • 김현기;김홍식;;김준동
    • 한국전기전자재료학회논문지
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    • 제28권12호
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    • pp.808-812
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    • 2015
  • Highly optical transparent photoelectric devices were realized by using a transparent metal-oxide semiconductor heterojunction of p-type NiO and n-type ZnO. A functional template of ITO nanowires (NWs) was applied to this transparent heterojunction device to enlarge the light-reactive surface. The ITO NWs/n-ZnO/p-NiO heterojunction device provided a significant high rectification ratio of 275 with a considerably low reverse saturation current of 0.2 nA. The optical transparency was about 80% for visible wavelengths, however showed an excellent blocking UV light. The nanostructured transparent heterojunction devices were applied for UV photodetectors to show ultra fast photoresponses with a rise time of 8.3 mS and a fall time of 20 ms, respectively. We suggest this transparent and super-performing UV responser can practically applied in transparent electronics and smart window applications.

수직배향된 산화아연 나노막대의 성장 및 발광특성에 관한 연구 (Metalorganic vapor-phase epitaxial growth of vertically well-aligned ZnO nanorods and their photoluminescent properties)

  • Jeon Yong-Ho;Park Won-Il;Lee Gyu-Cheol
    • 한국광학회:학술대회논문집
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    • 한국광학회 2002년도 하계학술발표회
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    • pp.174-175
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    • 2002
  • One-dimensional semiconductor nanowires and nanorods have attracted increasing interest due to their unique physical properties and diversity for potential electronic and photonic device applications., Unlike the conventional nanowires fabricated by metal catalyst-assisted vapor-liquid-solid (VLS) method, we developed metalorganic vapor-phase epitaxial (MOVPE) growth for which no catalyst is needed. The structural and photoluminecent properties will also be discussed. (omitted)

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A review of zinc oxide photoanode films for dye-sensitized solar cells based on zinc oxide nanostructures

  • Tyona, M.D.;Osuji, R.U.;Ezema, F.I.
    • Advances in nano research
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    • 제1권1호
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    • pp.43-58
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    • 2013
  • Zinc oxide (ZnO) is a unique semiconductor material that exhibits numerous useful properties for dye-sensitized solar cells (DSSCs) and other applications. Various thin-film growth techniques have been used to produce nanowires, nanorods, nanotubes, nanotips, nanosheets, nanobelts and terapods of ZnO. These unique nanostructures unambiguously demonstrate that ZnO probably has the richest family of nanostructures among all materials, both in structures and in properties. The nanostructures could have novel applications in solar cells, optoelectronics, sensors, transducers and biomedical sciences. This article reviews the various nanostructures of ZnO grown by various techniques and their application in DSSCs. The application of ZnO nanowires, nanorods in DSSCs became outstanding, providing a direct pathway to the anode for photo-generated electrons thereby suppressing carrier recombination. This is a novel characteristic which increases the efficiency of ZnO based dye-sensitized solar cells.

Synthesis of Vertically Aligned SiNW/Carbon Core-shell Nanostructures

  • 김준희;김민수;김동환
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.488.2-488.2
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    • 2014
  • Carbon-based materials such as carbon nanotubes and graphene have emerged as promising building blocks in applications for nanoelectronics and energy devices due to electrical property, ease of processability, and relatively inert electrochemistry. In recent years, there has been considerable interest in core-shell nanomaterials, in which inorganic nanowires are surrounded by inorganic or organic layers. Especially, carbon encapsulated semiconductor nanowires have been actively investigated by researchers in lithium ion batteries. We report a method to synthesize silicon nanowire (SiNW) core/carbon shell structures by chemical vapor deposition (CVD), using methane (CH4) as a precursor at growth temperature of $1000{\sim}1100^{\circ}C$. Unlike carbon-based materials synthesized via conventional routes, this method is of advantage of metal-catalyst free growth. We characterized these materials with FE-SEM, FE-TEM, and Raman spectroscopy. This would allow us to use these materials for applications ranging from optoelectronics to energy devices such as solar cells and lithium ion batteries.

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