• 제목/요약/키워드: quantum dot

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조합 합성 시스템의 미세유체반응기를 이용한 CdSe 양자점 합성 및 분석 (Synthesis and analysis CdSe Quantum dot with a Microfluidic Reactor Using a Combinatorial Synthesis System)

  • 홍명환;이덕희;강이승;이찬기;김범성;김남훈
    • 한국분말재료학회지
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    • 제23권2호
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    • pp.143-148
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    • 2016
  • A microfluidic reactor with computer-controlled programmable isocratic pumps and online detectors is employed as a combinatorial synthesis system to synthesize and analyze materials for fabricating CdSe quantum dots for various applications. Four reaction condition parameters, namely, the reaction temperature, reaction time, Cd/Se compositional ratio, and precursor concentration, are combined in synthesis condition sets, and the size of the synthesized CdSe quantum dots is determined for each condition. The average time corresponding to each reaction condition for obtaining the ultraviolet-visible absorbance and photoluminescence spectra is approximately 10 min. Using the data from the combinatorial synthesis system, the effects of the reaction conditions on the synthesized CdSe quantum dots are determined. Further, the data is used to determine the relationships between the reaction conditions and the CdSe particle size. This method should aid in determining and selecting the optimal conditions for synthesizing nanoparticles for diverse applications.

QLEDs 효율 및 안정성 향상을 위한 전하 수송 소재 개발 동향 (Research trend in the development of charge transport materials to improve the efficiency and stability of QLEDs)

  • 김예진;박수진;이동구;이원호
    • 접착 및 계면
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    • 제23권2호
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    • pp.17-24
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    • 2022
  • 양자점은 수 나노미터 크기의 반도체 나노입자로 우수한 발광 특성 및 색순도, 간단한 밴드갭 조절의 장점 때문에 이를 발광원으로 사용한 양자점 디스플레이가 차세대 디스플레이로 주목받고 있다. 하지만 전하 주입 불균형 문제로 인해서 소자의 효율 및 안정성에 큰 문제가 발생하고 이를 해결하기 위한 많은 연구가 진행되었다. 본 논문에서는 전자 및 정공 수송층에 중간층을 삽입하여 양자점 디스플레이의 발광과 수명 특성을 향상시킨 연구와 정공 수송층의 구조 변화를 통해서 정공 수송 능력을 향상시킨 연구들에 대해서 소개하고자 한다.

Size Control of PbS Colloidal Quantum Dots and Their Application to Photovoltaic Devices

  • Lee, Wonseok;Ryu, Ilhwan;Choi, Geunpyo;Yim, Sanggyu
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.249.1-249.1
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    • 2015
  • Quantum dots (QDs) are attracting growing attention for photovoltaic device applications because of their unique electronic, optical and physical properties. Lead sulfide (PbS) QDs are one of the most widely studied materials for the devices and known to have size-tunable properties. In this context, we investigated the relationship between the size of PbS QDs and two synthesizing conditions, a concentration of ligand, oleic acid in this work, and injection temperature. The inverted colloidal quantum dot solar cells based on the heterojunction of n-type zinc oxide layer and p-type PbS QDs were also fabricated. The size of the QDs and cell properties were observed to depend on both the QD synthesizing conditions, and hence the overall efficiency of the cell could vary even though the size of QDs used was same. The QD synthesizing conditions were finally optimized for the maximum cell efficiency.

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InAs/GaAs Self-organized Quantum Dots의 전기.광학적 특성 연구 (A Study on Electrical and Optical Characteristics of InAs/GaAs Self-organized Quantum Dots)

  • 김기홍;박종도;배인호;손정식;문병연;이주인
    • 한국전기전자재료학회논문지
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    • 제14권2호
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    • pp.99-103
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    • 2001
  • We present a detailed of the interband transitions of InAs/GaAs self-organized quantum dots(QDs) based on surface photovoltage(SPV), photoreflactance(PR) and photoluminescence(PL) spectroscopies. At room temperature, interband absorption transitions of QDs have been observed by using SPV spectrum, which clearly exhibits three well-resolved absorption transitions of QDs have been observed by using SPV spectrum, which clearly exhibits three well-resolved absorption peaks. The absorption line shape is Gaussian-like. Furthermore, the corresponding interband transitions are also observed in PR and PL experiments at 77K.

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Investigation of Carrier Transport Mechanism in Schottky Type InAs/GaAs Quantum Dot Solar Cells

  • 김호성;류근환;양현덕;박민수;김상혁;송진동;최원준;박정호
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.319.1-319.1
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    • 2014
  • We present the results on the indium tin oxide (ITO) Schottky barrier solar cells (SBSCs) with InAs quantum dots (QDs). The dependence of external quantum efficiency on the external bias voltage has been studied to anlayze carrier extraction through tunneling at room temperature.

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금속배선 칩 집적공정을 포함하는 질화물 반도체 LED 광소자 특성 연구 (A Study on the III-nitride Light Emitting Diode with the Chip Integration by Metal Interconnection)

  • 김근주;양정자
    • 반도체디스플레이기술학회지
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    • 제3권3호
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    • pp.31-35
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    • 2004
  • A blue light emitting diode with 8 periods InGaN/GaN multi-quantum well structure grown by metal-organic chemical vapor deposition was fabricated with the inclusion of the metal-interconnection process in order to integrate the chips for light lamp. The quantum well structure provides the blue light photoluminescence peaked at 479.2 nm at room temperature. As decreasing the temperature to 20 K, the main peak was shifted to 469.7 nm and a minor peak at 441.9 nm appeared indicating the quantum dot formation in quantum wells. The current-voltage measurement for the fabricated LED chips shows that the metal-interconnection provides good current path with ohmic resistance of 41 $\Omega$.

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나노물질 기반의 광변환층 개발 동향 (Advances in Nanomaterials-Based Color Conversion Layer)

  • 김동룡;최문기
    • 한국전기전자재료학회논문지
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    • 제35권6호
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    • pp.547-555
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    • 2022
  • Color conversion layer refers to a layer that converts the blue light emitted from the backlight into the red and green light. Heavy metal-free quantum dots and perovskite nanocrystals have attracted great attention as base materials for color conversion layers due to their outstanding optical characteristics. Here, we review recent advances in the development of color conversion layers based on quantum dots. First, we overview the representative optical characteristics of quantum dots and perovskite nanocrystals, and then introduce printing techniques for color converting layers including photolithography, inkjet printing, and nanoimprinting. Finally, we conclude this review with a brief perspective.