• 한국미생물·생명공학회지
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• 제38권3호
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• pp.227-234
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• 2010

Cytochrome P450 enzymes which require the supply of electrons from NAD(P)H have a great biotechnological impact as they catalyze valuable reactions on a vast variety of substrates. However, very limited biotechnological application has been reported so far due to their functional complexity, limited stability (instability) and, in most cases, low catalytic activity. In this present review, we introduce some possibilities for improving their defect by exploring electron transport system and substrate flexibility in field of Streptomyces cytochrome P450.

• Applied Science and Convergence Technology
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• 제23권3호
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• pp.128-133
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• 2014

We study the ballistic spin transport properties in a two-dimensional electron gas system in the presence of magnetic barriers using a transfer matrix method. We concentrate on the size-effect of the magnetic barriers parallel to a two-dimensional electron gas plane. We calculate the transmission probability of the ballistic spin transport in the magnetic barrier structure while varying the width of the magnetic barriers. It is shown that resonant tunneling oscillation is affected by the width and height of the magnetic barriers sensitively as well as by the inter-spacing of the barriers. We also consider the effect of additional electrostatic modulation on the top of the magnetic barriers, which could enhance the current spin polarization. Because all-semiconductor-based devices are free from the resistance mismatch problem, a resonant tunneling structure using the two-dimensional electron gas system with electric-magnetic modulation would play an important role in future spintronics applications. From the results here, we provide information on the physical parameters of a device to produce well-defined spin-polarized current.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1410-1412
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• 2005

We present that the electroluminescence (EL) efficiency can be improved by doping an electron transport layer (ETL) with organic materials which can make electron current increase. The electron transport layer of aluminum tris(8 -hydroxyquinoline) (Alq3) is doped with 2-(4-Biphenylyl)-5-(4-tertbutylphenyl)- 1,3,4-oxadiazole) (butyl-PBD) to enhance the electron mobility of the ETL. The higher quantum efficiency of device having ETL using Alq3 doped with butyl-PBD can be attributed to the improved electron and hole balance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.181-184
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• 2002

The electron transport coefficients in Air is analysed in range of E/N values from 100~1000(Td) by a MCS and BE method. This paper have calculated W, $ND_L$,$ ND_T$, Mean energy mixtures by $N_2+O_2$. The results gained that the values of the electron swarm parameters such as the electron drift velocity, longitudinal and transverse diffusion coefficients.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.934-941
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• 2000

We measured the electron transport coefficients, the electron drift velocity W and the longitudinal diffusion coefficient $D_{L}$ in the 0.526% and 5.05% $C_{3}F_{8}$-Ar mixtures over the E/N range from 0.01 Td to 100 Td by the double shutter drift tube, and compared the measured results by Hunter et al. with those. We determined the inelastic collision cross sections for the $C_{3}F_{8}$ molecule by the comparison of the present measurements and the calculation of electron transport coefficients in the $C_{3}F_{8}$-Ar mixtures by using a multi-term Boltzmann equation analysis.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.27-27
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• 2011

For the design of real applicable molecular devices, current-voltage properties through molecular nanostructures such as metal-molecule-metal junctions (molecular junctions) have been studied extensively. In thiolate monolayers on the gold electrode, the chemical bonding of sulfur to gold and the van der Waals interactions between the alkyl chains of neighboring molecules are important factors in the formation of well-defined monolayers and in the control of the electron transport rate. Charge transport through the molecular junctions depends significantly on the energy levels of molecules relative to the Fermi levels of the contacts and the electronic structure of the molecule. It is important to understand the interfacial electron transport in accordance with the increased film thickness of alkyl chains that are known as an insulating layer, but are required for molecular device fabrication. Thiol-tethered RuII terpyridine complexes were synthesized for a voltage-driven molecular switch and used to understand the switch-on mechanism of the molecular switches of single metal complexes in the solid-state molecular junction in a vacuum. Electrochemical voltammetry and current-voltage (I-V) characteristics are measured to elucidate electron transport processes in the bistable conducting states of single molecular junctions of a molecular switch, Ru(II) terpyridine complexes. (1) On the basis of the Ru-centered electrochemical reaction data, the electron transport rate increases in the mixed self-assembled monolayer (SAM) of Ru(II) terpyridine complexes, indicating strong electronic coupling between the redox center and the substrate, along the molecules. (2) In a low-conducting state before switch-on, I-V characteristics are fitted to a direct tunneling model, and the estimated tunneling decay constant across the Ru(II) terpyridine complex is found to be smaller than that of alkanethiol. (3) The threshold voltages for the switch-on from low- to high-conducting states are identical, corresponding to the electron affinity of the molecules. (4) A high-conducting state after switch-on remains in the reverse voltage sweep, and a linear relationship of the current to the voltage is obtained. These results reveal electron transport paths via the redox centers of the Ru(II) terpyridine complexes, a molecular switch.

• Journal of Plant Biology
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• 제35권3호
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• pp.247-252
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• 1992

iso-Butanol이 엽록체의 광합성 전자전달 활성에 미치는 영향을 연구하기 위하여 암조건하에서 시금치의 엽록체에 iso-butanol을 처리한 후 대조구와 비교하여 광계 II 활성과 광계 I 활성을 조사하였으며, 또한 iso-butanol이 틸라코이드 막단백질에 미치는 영향을 알아보기 위해 전기영동으로 틸라코이드 막단백질의 변화를 조사하였다. 광계 I 활성은 iso-butanol이 저농도(1-4%)일 때는 증가하였으나 고농도(5-9%) 에서는 감소되었다. 광계 II 활성은 iso-butanol의 농도가 0.6, 0.8, 1%에서는 각각 75%, 55% 및 25%로 활성이 감소하였다. Butanol 중에서 탄소수는 같으나 OH 기의 위치가 다른 1-butanol, sec-butanol, tert-butanol, iso-butanol이 광계 II의 전자전달계에 미치는 영향을 비교해 본 결과 OH 기를 중심으로 탄소의 배열이 직선상 일 때 저해효과가 크다는 것을 알 수 있었다. iso-butanol이 1차적으로 광계 II에 미치는 억제 부위는 0.8% iso-butanol 처리구에 DPC 첨가했을 때 DCIP 환원율이 93%로 증가하는 것으로 보아 광계 II의 산화 부위임을 알 수 있다. 0.8% iso-butanol 처리구에 외부에서 망간과 칼슘을 첨가하였을 때 광계 II 활성이 각각 83%와 79%로 보호된 것으로 보아 광계 II 활성 억제는 망간의 소실과 관계 있는 것으로 생각된다. 또한 1% iso-butanol 처리한 엽록체를 20배 희석하였을 때 활성이 78%로 회복되었다. iso-Butanol은 1% 이하의 저농도에서 광계 II 활성을 감소시킨데 비해 1% iso-butanol 처리구의 틸라코이드 막단백질의 SDS-PAGE에 의한 band pattern은 대조구와 유사하며 2% 처리구에서는 52 Kd 부근에서 미세한 band pattern의 차이가 있으며 5%의 iso-butanol 처리구의 틸라코이드 막단백질의 band는 전체적으로 많이 소실되었다. 이것으로 보아 iso-butanol은 가역적으로 광계 II의 산화부위에 관여하는 단백질에 영향을 주어 $Ca^{2+}와\;Mn^{2+}$ 이온의 친화력을 저하시켜 광계 II 활성을 억제시키고 또한 알코올의 R-group의 틸라코이드 막에 침투하여 막구조를 변형시키므로 광계 I 활성이 증가하며 고농도(5-9%)에서는 비가역적으로 막구조를 변경하여 광계 I 활성이 감소한 것으로 사료된다.

• 공업화학
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• 제9권5호
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• pp.710-714
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• 1998

Poly(p-phenylene vinylene), PPV를 발광층으로 하고 전자수송층(electron transport layer, ETL)이 도입된 이중 접합구조 유기 전기발광소자(electroluminescence device, ELD)를 제작하고 전기 발광 특성을 조사하였다. 전자 수송제로는 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole(PBD)를 사용하고 이를 분산시킬 기재 고분자(matrix polymer)로는 stilbene계 공단량체를 포함하는 poly(styrene-co-p-vinyl-trans-stilbene (PVTS)), poly(styrene-co-MeO-PVTS) 및 poly(styrene-co-MeO-ST)를 합성하였다. 이들 재료를 이용하여 이종 접합구조 ELD를 제조하였으며 poly(styrene-co-PVTS)를 기재 고분자로 쓴 EL 소자가 최대의 휘도를 나타냄을 확인하였다. Poly(styrene-co-MeO-PVTS) 및 poly(styrene-co-MeO-ST) 등 전자 주게 성질을 가진 methoxy기를 함유하는 기재 고분자를 쓴 EL 소자는 전자 수송층이 없는 ITO/PPV/Mg 단층 소자와 휘도가 유사 혹은 낮게 나타났다. Poly(styrene-co-PVTS)를 ETL에 쓴 EL 소자에 있어서 styrene보다 긴 conjugation 길이의 증가가 EL 발광 스펙트럼에 미치는 영향은 크지 않고 실제 발광은 PPV에 의해 주로 일어남이 관찰되었다.

• 한국전기전자재료학회논문지
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• 제35권1호
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• pp.93-97
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• 2022

We report highly efficient quantum dot light-emitting diodes (QLEDs) with TiO₂ nanoparticles (NPs) as an alternative electron transport layer (ETL) and poly (methyl methacrylate) (PMMA) as an insulating layer. TiO₂ NPs were applied as ETLs of inverted structured QLEDs and the effect of the addition of PMMA between ETL and emission layer (EML) on device characteristics was studied in detail. A thin PMMA layer supported to make the charge balance in the EML of QLEDs due to its insulating property, which limits electron injection effectively. Green QLEDs with a PMMA layer produced the maximum luminance of 112,488 cd/m² and a current efficiency of 25.92 cd/A. We expect the extended application of TiO₂ NPs as the electron transport layer in inverted structured QLEDs device in the near future.

• 센서학회지
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• 제32권6호
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• pp.455-461
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• 2023

We investigated the electrical characteristics of ZnO nanoparticles (NPs) with air exposure that is a widely used electron transport layer for quantum dot light-emitting diodes (QLEDs). Upon air exposure, we observed changes in the density of states (DOS) of the trap levels of ZnO NPs. In particular, with air exposure, the concentration of deep trap energy levels in ZnO NPs decreased and electron mobility significantly improved. Consequently, the air-exposed ZnO reduced leakage current by approximately one order of magnitude and enhanced the external quantum efficiency at the low driving voltage region of the QLED. In addition, based on the excellent conductivity properties, high-brightness QLEDs could be achieved.