• 제목/요약/키워드: nanoDot

검색결과 166건 처리시간 0.03초

박막 실리콘 태양전지의 광열화현상 연구: 비정질 실리콘 태양전지 및 나노양자점 실리콘 박막 태양전지 (Study of Light-induced Degradation in Thin Film Silicon Solar Cells: Hydrogenated Amorphous Silicon Solar Cell and Nano-quantum Dot Silicon Thin Film Solar Cell)

  • 김가현
    • 한국태양에너지학회 논문집
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    • 제39권1호
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    • pp.1-9
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    • 2019
  • Light induced degradation is one of the major research challenges of hydrogenated amorphous silicon related thin film silicon solar cells. Amorphous silicon shows creation of metastable defect states, originating from elevated concentration of dangling bonds during light exposure. The metastable defect states work as recombination centers, and mostly affects quality of intrinsic layer in solar cells. In this paper we present results of light induced degradation in thin film silicon solar cells and discussion on physical origin, mechanism and practical solutions of light induced degradation in thin film silicon solar cells. In-situ light-soaking IV measurement techniques are presented. We also present thin film silicon material with silicon nano-quantum dots embedded within amorphous matrix, which shows superior stability during light-soaking. Our results suggest that solar cell using silicon nano-quantum dots in abosrber layer shows superior stability under light soaking, compared to the conventional amorphous silicon solar cell.

Interband optical properties in wide band gap group-III nitride quantum dots

  • Bala, K. Jaya;Peter, A. John
    • Advances in nano research
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    • 제3권1호
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    • pp.13-27
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    • 2015
  • Size dependent emission properties and the interband optical transition energies in group-III nitride based quantum dots are investigated taking into account the geometrical confinement. Exciton binding energy and the optical transition energy in $Ga_{0.9}In_{0.1}N$/GaN and $Al_{0.395}In_{0.605}N$/AlN quantum dots are studied. The largest intersubband transition energies of electron and heavy hole with the consideration of geometrical confinement are brought out. The interband optical transition energies in the quantum dots are studied. The exciton oscillator strength as a function of dot radius in the quantum dots is computed. The interband optical absorption coefficients in GaInN/GaN and AlInN/AlN quantum dots, for the constant radius, are investigated. The result shows that the largest intersubband energy of 41% (10%) enhancement has been observed when the size of the dot radius is reduced from $50{\AA}$ to $25{\AA}$ of $Ga_{0.9}In_{0.1}N$/GaN ($Al_{0.395}In_{0.605}N$/AlN) quantum dot.

잉크젯 기법을 이용한 은 미세라인 형성 (Fabrication of Silver Micro Lines by Ink-Jet Method)

  • 변종훈;서동수;최영민;장현주;공기정;이정오;류병환
    • 한국세라믹학회지
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    • 제41권10호
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    • pp.788-791
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    • 2004
  • 입자크기가 수 nm인 고농도 은 나노 졸을 이용하여 잉크젯 기법으로 은 미세라인을 형성하고자 하였다. 고분자전해질을 사용하여 합성한 $10wt\%$ 농도의 은 나노 졸의 입자크기는 10nm 이하였으며, 은 나노 졸을 이용한 미세 라인의 인쇄특성은 은 나노 졸의 접촉각에 매우 깊은 관계를 갖고 있었다. 순수한 ITO 기판에서 은 나노 졸은 높은 접촉각을 나타내었으며, dot 형상이 나타났다. 그러나 100ppm의 Polyethylenimine(PEI)을 코팅한 ITO 기판은 젖음성이 크게 개선되었으며, 잉크젯 기법을 이용하여 $60\~100{\mu}m$의 선폭을 갖는 은 나노 졸의 미세라인 형성이 가능함을 확인할 수 있었다.

Effect of thiophenol-based ligands on photoluminescence of quantum dot nanocrystals

  • Moon, Hyungseok;Jin, Hoseok;Kim, Bokyoung;Kang, Hyunjin;Kim, Daekyoung;Chae, Heeyeop
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.197-197
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    • 2016
  • Quantum dot nanocrystals(QDs) have been emerged as next generation materials in the field of energy harvesting, sensor, and light emitting because of their compatibility with solution process and controllable energy band gap. Especially, characteristics of color tuning and color purity make it possible for QDs to be used photoluminescence materials. Photoluminescence devices with QDs have been researched for a long time. Photoluminescence quantum yield(PL QY) is important factor that defines the performance of Photoluminescence devices. One of the ways to achieve better PL QY is ligand modification. If ligands are changed to proper electron donating group, electrons can be confined in the core which results in enhancement of PL QY. Because of the reason, short ligands are preferred for enhancing PL QY. Thiophenol-based ligands are shorter than typical alkyl chain ligands. In this study, the effect of thiophenol-based ligands with different functional groups are investigated. Four different types of thiophenol-based organic materials are used as organic capping ligand. QDs with bare thiophenol and fluorothiophenol show better quantum yield compared to oleic acid.

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상압 분위기에서 QD 제작 및 이를 응용한 비휘발성 QD 메모리 특성 평가

  • 안강호;안진홍;정혁
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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    • pp.137-141
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    • 2005
  • Quantum dot(QD) 메모리용 silicon nano-particle을 corona 방전방법에 의해 상온에서 대량 발생하는 방법을 개발하였다. Silicon QD는 SiH4 가스를 코로나 방전 영역을 통과시켜 발생시켰으며, 코로나 전압은 2.75kV를 사용하였다. SiH4 몰농도 $0.33{\times}10^{-7}\;mol/l$ 일 경우 발생된 QD입자 크기는 약 10nm이며 기하학적 표준편차(geometric standard deviation)는 1.31이었다. 이 조건에서 nonvolatile quantum dot semiconductor memory (NVQDM)를 제작하였으며, 이렇게 제작된 NVQDM flat band voltage는 1.5 volt였다.

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다공성 알루미나 박막을 이용한 Au dot-arrays의 제작에 관한 연구 (A Study for the fabrication of Au dot-arrays using porous alumina film)

  • 정경한;박상현;신훈규;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.922-925
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    • 2003
  • The interest of self-organization materials that have uniform and regular structure in nano scale has been grown due to their utilization in various fields of nanotechnology. An attractive candidate among these materials is anodic aluminum oxide film, which are formed by anodization of aluminum in an appropriate acid solution. The anodic aluminum oxide film has a highly ordered porous structure with very uniform and nearly parallel pores that can be organized in an almost precise close-packed hexagonal structure. In this study, we attempt to make Au dot arrays, which were fabricated using anodic aluminum oxide film as an evaporation mask. The Au dot arrays have a uniform sized dots and spacing to its neighbors and the average diameter of Au dots is about 60 nm corresponding to them of the mask.

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