• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.254-254
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• 2016

Tin dioxide (SnO2) thin film is one of the most important n-type semiconducting materials having a high transparency and chemical stability. Due to their favorable properties, it has been widely used as a base materials in the transparent conducting substrates, gas sensors, and other various electronic applications. Up to now, SnO2 thin film has been extensively studied by a various deposition techniques such as RF magnetron sputtering, sol-gel process, a solution process, pulsed laser deposition (PLD), chemical vapor deposition (CVD), and atomic layer deposition (ALD) [1-6]. Among them, ALD or plasma-enhanced ALD (PEALD) has recently been focused in diverse applications due to its inherent capability for nanotechnologies. SnO2 thin films can be prepared by ALD or PEALD using halide precursors or using various metal-organic (MO) precursors. In the literature, there are many reports on the ALD and PEALD processes for depositing SnO2 thin films using MO precursors [7-8]. However, only ALD-SnO2 processes has been reported for halide precursors and PEALD-SnO2 process has not been reported yet. Herein, therefore, we report the first PEALD process of SnO2 thin films using SnCl4 and oxygen plasma. In this work, the growth kinetics of PEALD-SnO2 as well as their physical and chemical properties were systemically investigated. Moreover, some promising applications of this process will be shown at the end of presentation.

• Tribology and Lubricants
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• 제32권5호
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• pp.141-146
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• 2016

The diketopyrrolopyrrole (DPP) pigment is a bicyclic 8-π-electron system containing two lactam units. Typical DPP derivative pigments have melting points of over 350°C and very low solubility in most solvents, and show absorption in the visible region with a molar extinction coefficient of 33,000 dm²mol⁻¹ and strong photoluminescence with maxima in the range 500–600 nm. X-ray structure analyses of DPP show that the whole molecule is almost in one plane. The phenyl rings are twisted out of the heterocyclic plane and the intermolecular hydrogen bonding between neighboring lactam NH and carbonyl units influences the structure of the DPP pigment in the solid state. In this study, mono-N-alkylation and mono-N-arylation were undertaken for Pigment Red 264 or Pigment Orange 73 with alkyl halide and aryl halide, respectively, in the presence of sodium tert-butoxide as a base catalyst to improve the solubility of DPP pigments and their application as CO₂ indicators. The synthetic yield was in the range 11–88%. The indicator dyes are highly soluble in organic solvents and shows pH-dependent absorption (λ_max 501 and 572 nm for the protonated and deprotonated forms, respectively) and emission (λ_max 524 and 605 nm for the protonated and deprotonated forms, respectively) spectra. The mono-N-alkylated and mono-N-arylated DPP pigment was identified by ¹H-NMR (¹H-Nuclear Magnetic Resonance Spectrometer), FT-IR (Fourier Transform Infrared Spectroscopy), and MS (Mass Spectrometry). According to the results of color and hue properties obtained by a color matching analyzer, the synthesized DPP pigment material can be used as a CO₂ indicator.

• 공업화학
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• 제8권2호
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• pp.237-245
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• 1997

DEAE-chitin은 alkali-chitin 용액에 DEAE HCl을 이용하여 제조하였다. 제조된 DEAE-chitin은 물과 유기용매에 대한 향상된 용해성을 나타내었다. DEAE-chitin은 chitin의 탈아세틸화반응보다 온화한 조건인 sodium borohydride를 함유하고 있는 10% 수산화나트륨 수용액으로 $80^{\circ}C$에서 9시간동안 탈아세틸화반응을 행하여 DEAE-chitosan을 제조하였고, DEAE-chitin의 양이 온성을 증가시키기 위해 ethyl halide를 이용하여 4차화시킴으로써 4차 암모늄기를 가진 TEAE-chitin유도체를 각각 합성하였다. 이들 합성유도체들의 반응에 따른 구조변화는 FTIR, $^1H$ NMR 등으로 확인하였고, 카올린 현탁액을 이용한 응집실험결과 pH가 약 알칼리일 때, 그리고 수지농도가 8ppm일 때 최적의 응집성능을 나타냄을 알 수 있었다.

• 한국인쇄학회지
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• 제8권1호
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• pp.53-70
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• 1990

It is well known that viologens such as 1.1 - disubstituted 4, 4` - bipyridinium salts and those used as redox indicator, herbicide and electrocheromic display device because those possess the lowest redox potential in any organic system. Viologen salts produced reversible high blue color under the influence of radical cation by photoreduction This study is related to the synthesis of viologen derivatives and the photoreduction property in water solution stats and the polar aprotic polyvinylpyrrolidone(PVP) matrix.

• 세라미스트
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• 제23권2호
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• pp.145-165
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• 2020

Halide perovskites are promising photovoltaic materials due to their excellent optoelectronic properties like high absorption coefficient, low exciton binding energy and long diffusion length, and single-junction solar cells consisting of them have shown a high certified efficiency of 25.2%. Despite of high efficiency, perovskite photovoltaics show poor stability under actual operational condition, which is the mostly critical obstacle for commercialization. Given that the stability of the perovskite devices is significantly affected by charge-transporting layers, the use of inorganic charge-transporting layers with better intrinsic stability than the organic counterparts must be beneficial to the enhanced device reliability. In this review article, we summarized a number of studies on the inorganic charge-transporting layers of the perovskite solar cells, especially focusing on their effects on the enhanced device reliability.

• 한국인쇄학회지
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• 제9권1호
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• pp.27-44
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• 1991

In this research, double-layered photoconductor consist of the carrier generation layer(CGL) of ${\varepsilon}$ type copper phthalocyanine thin film by an aqueous coating method and the carrier transport layer(CGL) of polyvinyl carbazol(PVK) by spin coating. We inverstigated effect of the surfactant solution and cathod electrolysis to the crystal type of ${\varepsilon}$-CuPc in CGL with TEM, SEM and X-ray diffraction spectroscopy and studied the mechanism of an aqueous coating for the preparation of CGL. The effect of the washing of CGL about the electrophotographic characteristics of the ${\varepsilon}$-CUPC/PVK double-layered photoconductors is studied also.

• Current Photovoltaic Research
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• 제3권4호
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• pp.107-111
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• 2015

Current characteristic curve of an illuminated solar cell was used to determine its reverse saturation current density ($J_0$), ideality factor (n) and resistances, by using numerical diode simulation. High efficiency amorphous silicon, heterojunction crystalline Si (HIT), plastic and organic-inorganic halide perovskite solar cell shows n=3.27 for a-Si and n=2.14 for improved HIT cell as high and low n respectively, while the perovskite and plastic cells show n=2.56 and 2.57 respectively. The $J_0$ of these cells remain within $7.1{\times}10^{-7}$ and $1.79{\times}10^{-8}A/cm^2$ for poorer HIT and improved perovskite solar cell respectively.

• Bulletin of the Korean Chemical Society
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• 제11권1호
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• pp.65-69
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• 1990

The nucleophilic substitution reactions of naphthalene-1,5-disulfonyl chloride and 4-fluorosulfonylbenzenesulfonyl chloride with p-substituted anilines and methyl substituted pyridines in methanol-acetonitrile mixtures and hydrolyses of those disulfonyl halides have been studied by means of conductometric and polarographic methods. A large difference in the selective parameter, ${\rho}_N$ between mono-sulfonyl chloride and disulfonyl halide can be taken as an evidence that the second $SO_2Cl$ grolup of naphthalene-1,5-disulfonyl chloride also takes part in the reaction in contrast to sulfonyl fluoride in 4-fluorosulfonylbenzenesulfonyl chloride, which only acts as a substituent in the nucleophilic substitution reaction.

• Electronic Materials Letters
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• 제14권6호
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• pp.657-668
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• 2018

Organic-inorganic hybrid lead halide perovskites have been extensively investigated for various optoelectronic applications. Particularly, owing to their ability to form highly crystalline and homogeneous films utilizing low-temperature solution processes (< $150^{\circ}C$), perovskites have become promising photoactive materials for realizing high-performance flexible solar cells. However, the current use of mesoporous $TiO_2$ scaff olds, which require high-temperature sintering processes (> $400^{\circ}C$), has limited the fabrication of perovskite solar cells on flexible substrates. Therefore, the development of a low-temperature processable charge-transporting layer has emerged as an urgent task for achieving flexible perovskite solar cells. This review summarizes the recent progress in low-temperature processable electron- and hole-transporting layer materials, which contribute to improved device performance in flexible perovskite solar cells.

• 약학회지
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• 제38권5호
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• pp.516-519
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• 1994

The derivatives of methyl 5-hydroxy-dinaphtho[1,2-2',3']furan-7,12-dione-6-carboxylate (MHDDC) were synthesized by condensing alkyl sulfate or alkyl halide with MHDDC in organic solvent, and their structures were identified by NMR, MS, UV, IR etc. We also investigated the physico-chemical properties, physiological activities, and set up the micro-analytical method of the compounds.