• 제목/요약/키워드: Optical conductivity

검색결과 380건 처리시간 0.03초

Electrical and optical properties of ZnO:Al thin films prepared by reactive sputtering method (반응성 sputtering법으로 제막된 ZnO : Al 박막의 전기.광학적 특성)

  • 유병석;유세웅;이정훈
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • 제6권4호
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    • pp.480-492
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    • 1996
  • AZO (Aluminum doped Zinc Oxide) transparent conducting thin films were fabricated by reactive DC mangnetron sputtering method using zinc target containing 2 wt% of Al. Transition range with optimum transmittance and conductivity was obtained by contrlling partial pressure of reactive oxygen gas. Sputtering condition for this transition range could be kept stable by regulating the target voltage. According to XRD analysis, there was only one peak for (002) plane in AZO films and the films deposited in transition range.

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A study on the temperature dependence of electrical conductivity and optical absorption spectrum of poly(3-alklythiophene) in phase transition states (상전이상태에 있어서 poly(3-alkylthiophene)의 전기전도도와 광학흡수 spectrum의 온도의존성에 관한 연구)

  • 박복기
    • Electrical & Electronic Materials
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    • 제5권1호
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    • pp.52-70
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    • 1992
  • Poly(3-alkythiophene)은 온도에 따라 전기적 광학적인 성질의 현저한 변화가 관측되었다. poly(3-alkylthiophene)의 전기전도도는 온도가 상승함에 따라 증가하지만 최대치를 유지한 후 용융점에서 단게적으로 감소한다. 가열과 냉각과정 동안 전기전도도의 온도의존성에서 hysteresis가 관측되었다. 이 변칙은 carrier확산에 따른 분자구조 변화의 강한 영향인 것으로 생각된다. 흡수 spectrum 또한 상전이에서 급격히 변화한다. poly(3-alkylthiophene)의 흡수 peak는 액체상태에서 가열하면 energy는 높게 이동한다. 그러나 흡수 edge의 이동은 비교적 작다. 그렇지만 고체-액체 상전이에서 흡수 edge는 energy가 높은 쪽으로 이동한다. 이러한 현상은 고체-액체 상전이에서 poly(3-alkylthiophene)의 구조가 현저하게 변화하고 있는 것으로 설명되며 공역 길이가 짧게되는 것은 큰 구조 변화에 의해 공역계의 평면성 감소에 의한 결과로 생각한다.

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플렉서블 디스플레이용 투명전극 제조를 위한 ITO 대체소재 연구동향

  • Kim, Seon-Ok;Choe, Su-Bin;Kim, Jong-Ung
    • Ceramist
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    • 제21권1호
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    • pp.12-23
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    • 2018
  • As the flexible displays have been considered as a breakthrough to make a new electronics category, transparent electrodes have also confronted with an emerging issue, i.e., they also need to be mechanically flexible. For this to be made possible, a transparent electrode capable of withstanding large amounts of strain must be developed. Indium tin oxide (ITO) has been one of the most widely adopted transparent electrodes for displays and other transparent electronics, mainly supported by its high electrical conductivity and optical transparency. However, its brittle nature has forced the display industry to search for other alternatives. Recently, advances in nano-material researches have opened the door for various transparent conductive materials, which include carbon nanotube, graphene, Ag and Cu nanowire, and printable metal grids. Here we reviewed recently-published research works introducing flexible displays, all of which are employing the novel candidates for a conducting material.

Surface Oxidation Effect During high Temperature Vacuum Annealing on the Electrical Conductivity of ZnO thin Films Deposited by ALD

  • Kim, Jin-Yong;Choi, Yong-June;Park, Hyung-Ho
    • Journal of the Microelectronics and Packaging Society
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    • 제19권2호
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    • pp.73-78
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    • 2012
  • The chemical, electrical, and optical properties of ZnO and Al-doped ZnO films after high temperature annealing were studied. The resistivity increased significantly after annealing at $600^{\circ}C$ under $10^{-10}$ Torr atmosphere. The mechanism of the resistivity change was explored using photoemission spectroscopy and photoluminescence spectrometer. The results indicated that the amount of oxygen deficient region O-Zn bonds decreased and oxygen vacancy was decreased after the high temperature vacuum annealing. The increase in the resistivity of ZnO and Al-doped ZnO films was resulted from the decrease in carrier concentration due to a decrease in the amount of oxygen deficiency.

Optical Analysis of p-Type ZnO:Al Thin Films

  • Jin, Hu-Jie;So, Byung-Moon;Park, Bok-Kee;Park, Choon-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.68-69
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    • 2007
  • We have prepared p-type ZnO:Al films in pure oxygen ambient on n-type Si (100) and homo buffer layers by RF magnetron sputtering system. Hall effect measurement shows that the film annealed at $600^{\circ}C$ possesses p-type conductivity and the film annealed $800^{\circ}C$ does not. PL spectra show different properties of p- and n-type ZnO film. The corresponding peaks of PL spectra of p- and n-type show at about same positions. The intensities of high photon energy of n-type film on buffer shows decreasing tendency.

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산소 플라즈마로 처리한 전도성 투명 BZO(ZnO:B)박막에 대한 전기적 특성

  • Gang, Jeong-Uk;Yu, Ha-Jin;Son, Chang-Gil;Jo, Won-Tae;Park, Sang-Gi;Choe, Eun-Ha;Gwon, Gi-Cheong
    • Proceedings of the Korean Vacuum Society Conference
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.477-477
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    • 2010
  • 태양전지용 TCO(Transfer Conductivity Oxide)는 가시광선 영역에서 높은 광 투과도(optical transmittance), 낮은 저항(resistivity), 우수한 박막 표면 거칠기(roughness) 등의 특성이 요구된다. 현재 가장 많이 사용되는 투명전극은 ITO(Indium Tin Oxide)가 보편적이다. 하지만 ITO에 사용되는 원료 재료인 In이 상대적으로 열적 안정성이 낮아 제조과정에서 필수적으로 수반되는 열처리가 제한적이며, 높은 원료 단가로 인하여 경제적인 측면에서 약점으로 지적되고 있다. 이러한 ITO 투명전극의 대체 재료로서 최근 ZnO 박막의 연구가 활발히 이루어지고 있다. MOCVD(Metal-Organic chemical vapor deposition)로 Soda lime glass 기판위에 약 900nm의 두께로 증착한 BZO(Boron-zinc-oxide)박막을 수소 플라즈마 처리공정을 한 뒤 산소 플라즈마를 이용하여 재처리 하였다. 산소 플라즈마 처리 공정은 RIE(Reactive Ion Etching)방식의 플라즈마 처리 장치를 사용하였고 공정 조건은 13.56 MHz의 RF주파수를 사용하여 RF 전력, 압력, 기판 온도 등을 변화시켜 BZO 박막의 전기적 특성을 측정 및 분석하였다.

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Hybrid Organic-Inorganic Films Fabricated Using Atomic and Molecular Layer Deposition Techniques

  • George, Steven M.
    • Proceedings of the Korean Vacuum Society Conference
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.75.1-75.1
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    • 2013
  • Atomic layer deposition (ALD) and molecular layer deposition (MLD) are based on sequential, self-limiting surface reactions that produce atomic layer controlled and conformal thin film growth. ALD can deposit inorganic films and MLD can deposit films containing organics. ALD and MLD can be used together to fabricate a wide range of hybrid organic-inorganic alloy films. The relative fraction of inorganic and organic constituents can be defined by controlling the ratio of the ALD and MLD reaction cycles used to grow the film. These hybrid films can be tuned to obtain desirable mechanical, electrical and optical properties. This talk will focus on the growth and properties of metal alkoxide films grown using metal precursors and various organic alcohols that are known as "metalcones". The talk will highlight the tunable mechanical properties of alucone alloys grown using Al2O3 ALD and alucone MLD and the tunable electrical conductivity of zincone alloys grown using ZnO ALD and zincone MLD with DEZ and hydroquinone as the reactants.

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Synthesis and Dispersion Stabilization of Indium Tin Oxide Nanopowders by Coprecipitation and Sol-Gel Method for Transparent and Conductive Films

  • Cho, Young-Sang;Hong, Jeong-Jin;Kim, Young Kuk;Chung, Kook Chae;Choi, Chul Jin
    • Korean Journal of Metals and Materials
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    • 제48권9호
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    • pp.831-841
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    • 2010
  • Indium tin oxide (ITO) nanopowders were synthesized by coprecipitation and the sol-gel method to prepare a stable dispersion of ITO nano-colloid for antistatic coating of a display panel. The colloidal dispersions were prepared by attrition process with a vibratory milling apparatus using a suitable dispersant in organic solvent. The ITO coating solution was spin-coated on a glass panel followed by the deposition of partially hydrolyzed alkyl silicate as an over-coat layer. The double-layered coating films were characterized by measuring the sheet resistance and reflectance spectrum for antistatic and antireflective properties.

A Theoretical Study on the Low Transition Temperature of VO2 Metamaterials in the THz Regime

  • Kyoung, Jisoo
    • Current Optics and Photonics
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    • 제6권6호
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    • pp.583-589
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    • 2022
  • Vanadium dioxide (VO2) is a well-known material that undergoes insulator-to-metal phase transition near room temperature. Since the conductivity of VO2 changes several orders of magnitude in the terahertz (THz) spectral range during the phase transition, VO2-based active metamaterials have been extensively studied. Experimentally, it is reported that the metal nanostructures on the VO2 thin film lowers the critical temperature significantly compared to the bare film. Here, we theoretically studied such early transition phenomena by developing an analytical model. Unlike experimental work that only measures transmission, we calculate the reflection and absorption and demonstrate that the role of absorption is quite different for bare and patterned samples; the absorption gradually increases for bare film during the phase transition, while an absorption peak is observed at the critical temperature for the metamaterials. In addition, we also discuss the gap width and VO2 thickness effects on the transition temperatures.

Terahertz Characteristics of Hydroxygraphene Based on Microfluidic Technology

  • Boyan Zhang;Siyu Qian;Bo Peng;Bo Su;Zhuang Peng;Hailin Cui;Shengbo Zhang;Cunlin Zhang
    • Current Optics and Photonics
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    • 제7권4호
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    • pp.463-470
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    • 2023
  • Hydroxygraphene as a kind of functionalized graphene has important applications in composite, photoelectric and biological materials. In the present study, THz and microfluidic technologies were implemented to study the THz transmission characteristics of hydroxygraphene with different concentrations and residence times in magnetic and electric fields. The results show that the THz transmission intensity decreases with the increase in sample concentration and duration of an applied electric field, while it increases by staying longer in the magnetic field. The phenomenon is analyzed and explained in terms of hydrogen bond, conductivity and scattering characteristics. The results establish a foundation for future research on the THz absorption characteristics of liquid graphene based on microfluidic technology in different external environments. It also provides technical support for the application and development of graphene in THz devices.