• 제목/요약/키워드: Donor-acceptor

검색결과 443건 처리시간 0.028초

전하 이동을 이용한 실세스퀴옥산/폴리스티렌 하이브리드 (Silsesquioxane/Polystyrene Hybrid Materials via Charge Transfer Interactions)

  • 최지원;요시키 주조
    • 폴리머
    • /
    • 제31권2호
    • /
    • pp.136-140
    • /
    • 2007
  • Carbazole(electron donor)그룹과 dinitrobenzene(electron acceptor)그룹을 이용하여 전하 이동 작용이 실세스퀴옥산/고분자 하이브리드의 형성 메커니즘으로서 작용할 수 있는지 살펴보는 연구를 진행하였다. 하이브리드 실험은 새롭게 합성된 Poly(carbazole-styrene) (PS/D)와 dinitrobenzyl silsesquioxane (Cube/A)의 톨루엔 용액을 혼합/캐스팅을 하여 만들어진 필름을 이용하였으며 상분리가 없는 투명한 하이브리드 필름이 일부 조건에서 얻어졌다. PS/D및 Cube/A의 $^1H-NMR$분석, 그리고 하이브리드 필름들의 UV 흡수 실험은 실세스퀴옥산에 의한 입체 장애 효과가 없는 조건에서는 acceptor와 donor가 1:1로 전하 이동 착물을 형성할 수 있지만, 상분리가 없는 투명한 실세스퀴옥산 하이브리드는 acceptor/donor의 비율이 0.7 : 1 이하에서 형성된다는 것을 보여주었다. 이 결과들은 또 실세스퀴옥산 한 분자 당 평균 4개의 전하 이동 착물이 형성된다는 하이브리드 나노 구조에 대한 정보도 제공하였다.

시간상관 단일광자 계수법에의한 Rhodamine 6G에서 Malachite Green으로의 에너지 전달 연구 (Study for Energy Transfer from Rhodamine 6G to Malachite Green Using Time Correlated Single Photon Counting Method)

  • 김현수;엄효순;최규관;정홍식;김웅
    • 한국광학회지
    • /
    • 제2권4호
    • /
    • pp.203-208
    • /
    • 1991
  • 모드동기된 아르곤 이온 레이저를 여기광원으로 사용한 시간상관 단일광자 계수장치를 이용하여 에틸렌글리콜 용매 내에서 Rhodamine 6G에서 Malachite Green으로의 비복사 에너지전달과정을 연구하였다. 측정된 donor의 형광소멸곡선을 full-fitting 방법으로 분석 처리하여 acceptor 농도의 변화에 따른 환산농도와 임계전이거리를 구했다. donor의 농도가 acceptor의 농도 보다 클때는 donor-donor의 원거리 쌍극자 모멘트에 의한 에너지 이주 효과를 고려해야하며 Forster 모델 보다 Huber 모델이 더 적절하였다.

  • PDF

Two-Photon Absorption Cross Sections of Dithienothiophene-Based Molecules

  • Chung, Myung-Ae;Lee, Kwang-Sup;Jung, Sang-Don
    • ETRI Journal
    • /
    • 제24권3호
    • /
    • pp.221-225
    • /
    • 2002
  • We performed nonlinear transmission measurements and quantum-chemical calculations on dithienothiophene(DTT)-based molecules to gain insight into the effect of acceptor and donor groups on two-photon absorption(TPA) properties. The TPA intensity showed dispersion characteristics of the single-photon absorption spectrum. When the molecules included an asymmetric donor-acceptor pair, the single- and two-photon absorption maximum wavelengths were red-shifted more than when the molecules had a symmetric donor-donor structure. We interpreted this result as indicating that the $S_2$ state plays the dominating role in the absorption process of molecules with a symmetric structure. The experimental TPA ${\delta}$ values at the absorption peak wavelength showed a dependence on the structural variations. We found the self-consistent force-field theory and Hartree-Fock Hamiltonian with single configuration interaction formalism to be valid for evaluating TPA ${\delta}$. Although the quantum-chemical calculations slightly underestimated the experimental ${\delta}$ values obtained from nonlinear trans -mission measurements, they reasonably predicted the dependence of the ${\delta}$ value on the structural variations. We confirmed the role of molecular symmetry by observing that donor-donor substituted structure gave the highest experimental and theoretical TPA ${\delta}$ values and that the donor-acceptor substituted structure showed a greater red-shift in the TPA absorption maximum wavelength. Overall, the theoretical ${\delta}$ values of DTT-based molecules were in the order of $10^{-46}\;cm^4{\cdot}s{\cdot}photon^{-1}$ and are higher than that of AF-50 by nearly two orders of magnitude.

  • PDF

Detonation transmission with an abrupt change in area

  • Hsu, Yao-Chung;Chao, Yei-Chin;Chung, Kung-Ming
    • Advances in aircraft and spacecraft science
    • /
    • 제5권5호
    • /
    • pp.533-550
    • /
    • 2018
  • Detonation transmission between propane/oxygen (donor) and propane/air (acceptor) with an abrupt area change is experimentally studied. In the donor, there are two types of incident detonation waves: A self-sustained Chapman-Jouguet (CJ) detonation wave and an overdriven detonation wave that is a result of the difference in the initial donor pressure ratios. The piston work is used to characterize the strength of the incident detonation wave. For an incident CJ detonation wave, the re-initiation of a detonation wave in the acceptor depends on the initial pressure in the donor and the expansion ratio. The axisymmetric and non-axisymmetric soot patterns respectively correspond to direct detonation and detonation re-initiation. For an incident overdriven detonation wave, the re-initiation of a detonation wave in the acceptor strongly depends on the degree of overdrive.

Ca와 Nb가 첨가된 $BaTiO_3$의 결함화학 (Defect Chemistry of Ca and Nb doped $BaTiO_3$)

  • 정재호;한영호;박순자
    • 한국재료학회지
    • /
    • 제4권7호
    • /
    • pp.798-807
    • /
    • 1994
  • $BaTio_{3}$에 Ca가 첨가되면 상온 저항을 증가시키며 이는 $Ca^{2+}$$Ti^{4+}$를 치환하여 acceptor 불순물을 형성하기 때문이라고 생각된다. 그러나 $Ca^{2+}$$Ti^{4+}$보다 이온 반경이 크므로 그 자리를 치환하지 않는다는 주장도 있다. 본 실험에서는 $BaTiO_{3}$에 의한 acceptor가 존재하는지 알아보기 위하여 Ba/(Ti+Ca+Nb)=1이 되도록 Ca와 Nb를 첨가하여 산소 분압의 변화에 따른 고온 평형 전기 전도도를 측정하였다. 측정은 $1000^{\circ}C$에서 행하였으며 산소 분압은 $10^{-15}$ ~ 1 기압의 범위에서 조절하였다. 첨가된 Ca와 Nb의 농도를 변화시킨 결과, acceptor와 donor의 상호 보상 효과가 나타났다. 즉, Nb에 의한 donor를 보상하는 acceptor가 존재함을 확일하였고, 전도도 곡선의 결함 화학적인 해석에 의하여 Ca가 Ti자리를 치환함을 알았다. 이러한 acceptor의 존재는 ICTS에 의해서도 확인되었다.

  • PDF

New Design and Synthesis of Donor-Acceptor units by Introducing Boron Based to Non-Boron based Semiconductor for high Voc OPV

  • Ryu, Ka Yeon;Cho, Kyuwan;Kim, Won-Suk;Kim, Kyungkon
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
    • /
    • pp.432.2-432.2
    • /
    • 2016
  • A new A-D-A type (Acceptor-Donor-Acceptor) conjugated based on pyridine-borane complex (Donor), non-boron fluorine (Donor) and 2,5-bis(alkyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) (Acceptor) were designed and synthesized via Pd-catalyzed Suzuki cross-coupling reaction. The synthesized boron based complex exhibited high electron affinity, which indicates deep HOMO energy levels and good visible absorption led to their use as donors in BHJ (bulk heterojunction) solar cells. Inverted devices were fabricated, reaching open-circuit voltage as high as 0.91eV. To probe structure-property relationship and search for design principle, we have synthesized pyridine-boron based electron donating small molecules. In this study, we report a new synthetic approach, molecular structure, charge carrier mobility and morphology of blended film and their correlation with the photovoltaic J-V characteristics in details.

  • PDF

F$\ddot{o}$rst energy transfer 를 적용한 준고체 DSSC 의 효율향상 (Enhanced Light Harvesting from F$\ddot{o}$rst-type resonance Energy Transfer in the Quasi-Solid State Dye-Sensitized Solar Cells)

  • 천종훈;이정관;양현석;김재홍
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
    • /
    • pp.117.1-117.1
    • /
    • 2011
  • We have demonstrated Forst-type resonance energy transfer (FRET) in the quasi-solid type dye-sensitized solar cells between organic fluorescence materials as an energy donor doped in polymeric gel electrolyte and ruthenium complex as an energy acceptor on surface of $TiO_2$. The strong spectral overlap of emission/absorption of energy donor and acceptor is required to get high FRET efficiency. The judicious choice of energy donor allows the enhancement of light harvesting characters of energy acceptor in quasi-solid dye sensitized solar cells which increase the power conversion efficiency. The enhanced light harvesting effect by the judicious choice/design of the fluorescence materials and sensitizing dyes permits the enhancement of photovoltaic performance of DSSC.

  • PDF

Solution-processed Organic Trilayer Solar Cells Incorporating Conjugated Polyelectrolytes

  • Cha, Myoung Joo;Walker, Bright;Seo, Jung Hwa
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
    • /
    • pp.192.1-192.1
    • /
    • 2014
  • We report solution-processed organic trilayer solar cells consisting of poly (3-hexylthiophene) (P3HT), a conjugated polyelectrolyte (CPE) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), wherein the effect CPE layer thickness on device properties was investigated. The current-voltage characteristics under illumination and dark as well as photoluminescence were characterized using various concentrations (0.02, 0.1, and 0.3wt%) of to deposit the CPE interlayer between the donor and acceptor layers. We also investigated the influence of molecular dipole moments in the trilayer solar cells by external stimuli. These results provide an experimental approach for investigating the influence of interfacial dipoles on solar cell parameters when placed between the donor and acceptor and allow us to obtaining fundamental information about the donor/acceptor interface in organic solar cells.

  • PDF