• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2835-2838
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• 2013

• Applied Chemistry for Engineering
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• v.20 no.3
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• pp.273-278
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• 2009

A series of poly[2-(2,6-dimethylpyran-4-ylidene)malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PM-PPV), poly[2-{2,6-Bis-[2-(5-bromothiophen-2-yl)-vinyl]-pyran-4-ylidene}-malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PMT-PPV) and poly[2-[2,6-Bis-(2-{4-[(4-bromophenyl)-phenylamino]-phenyl}-vinyl)-pyran-4-ylidene]-malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PMTPA-PPV) were synthesized by the Heck coupling reaction. The band gap of PM-PPV, PMT-PPV and PMTPA-PPV were 2.18 eV, 1.90 eV and 2.07 eV, respectively. The LUMO energy levels of PM-PPV, PMT-PPV and PMTPA-PPV were 3.65 eV, 3.54 eV and 3.62 eV, respectively and the HOMO energy levels of those were 5.83 eV, 5.61 eV and 5.52 eV, respectively. The photovoltaic devices based on the polymers was fabricated. The efficiency of the solar cells based on PM-PPV, PMT-PPV and PMTPA-PPV were 0.028%, 0.031% and 0.11%, respectively and the open circuit voltage (Voc) was 0.59 V~0.69 V under AM 1.5 G and 1 sun condition ($100mA/cm^2$).

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.137-141
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• 2010

Poly [4,7-Di-thiophen-2-yl-benzo(1,2,5)thiadiazole]-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene (PPVTBT) was synthesized by the Heck coupling reaction between 4,7-Di-thiophen-2-yl-benzo(1,2,5)thiadiazole and 1,4-bis(dodecyloxy)-2,5-divinylbenzene. The maximum absorption and band gap of PPVTBT were 550 nm and 1.74 eV, respectively. The HOMO and LUMO energy level of PPVTBT were -5.24 eV and -3.50 eV, respectively. The photovoltaic device based on the blend of PPVTBT and (6)-1-(3-(methoxycarbonyl)propyl)-{5}-1-phenyl[5,6]-$C_{61}$ (PCBM) (1 : 6 by weight ratio) was fabricated. The efficiency of device was 0.16%. The short circuit current density (Jsc), fill factor (FF) and open-circuit voltage (Voc) of the device was $0.74mA/cm^{2}$, 31% and 0.71 V, respectively, under AM 1.5 G and 1 sun condition ($100mA/cm^{2}$).

• Polymer(Korea)
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• v.39 no.1
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• pp.71-77
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• 2015

We synthesized a low band gap alternating copolymer containing electron-rich units (i.e. dithienosiloles and benzodithiophenes) and electron-deficient units (i.e. difluorobenzothiadiazoles) for high performance organic solar cells. The polymer was prepared by the Stille coupling reaction and characterized using $^1H$ NMR, GPC, TGA, UV-visible absorption spectroscopy, and cyclic voltammetry. Solar cells were fabricated in a structure of ITO/PEDOT:PSS/polymer: $PC_{70}BM/Al$ with five different blending ratios of polymer and $PC_{70}BM$ (1:1.5, 1:2, 1:3, 1:3.5 and 1:4 by weight ratio). The best efficiency was achieved from the 1:3 ratio of polymer and $PC_{70}BM$ in the photoactive layer, and TEM revealed that there is an optimal nanoscale phase separation between polymer and $PC_{70}BM$ in the 1:3 ratio blend film.

• Polymer(Korea)
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• v.39 no.2
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• pp.225-234
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• 2015

In this study, we proposed to synthesize thermally stable, soluble and conjugated Schiff base polymer (SbP). For this reason, a specific molecule namely 4,4'-thiodiphenol which has sulfur and oxygen bridge in its structure was used to synthesize bi-functional monomers. Bi-functional amino and carbonyl monomers namely 4,4'-[thio-bis(4,1-phenyleneoxy)] dianiline (DIA) and 4,4'-[thiobis(4,1-phenyleneoxy)]dibenzaldehyde (DIB) were prepared from the elimination reaction of 4,4'-thiodiphenol with 4-iodonitrobenzene and 4-iodobenzaldehyde, respectively. The structures of products were confirmed by elemental analysis, FTIR, $^1H$ NMR and $^{13}C$ NMR techniques. The molecular weight distribution parameters of SbP were determined by size exclusion chromatography (SEC). The synthesized SbP was characterized by solubility tests, TG-DTA and DSC. Also, conductivity values of SbP and SbP-iodine complex were determined from their solid conductivity measurements. The conductivity measurements of doped and undoped SbP were carried out by Keithley 2400 electrometer at room temperature and atmospheric pressure, which were calculated via four-point probe technique. When iodine was used as a doping agent, the conductivity of SbP was observed to be increased. Optical band gap ($E_g$) of SbP was also calculated by using UV-Vis spectroscopy. It should be stressed that SbP was a semiconductor which had a potential in electronic and optoelectronic applications, with fairly low band gap. SbP was found to be thermally stable up to $300^{\circ}C$. The char of SbP was observed 29.86% at $1000^{\circ}C$.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.825-828
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• 2005

In this paper, we propose a new nonvolatile unit memory cell and proposal peripheral circuit using the polymer material. Memory that relies on bistable behavior- having tow states associated with different resistances at the same applied voltage - has attracted much interest because of its nonvolatile properties. Such memory may also have other merits, including simplicity of structure and manufacturing, and the small size of memory cells. We have plotted the load line graphs for the use of a polymer memory character, hence we have designed in the band-gap reference shape of a write/erase drive, and then designed in the 2-stage differential amplifier shape of a sense amplifier in the consideration of a low current characteristic of a polymer memory cell. The simulation result shows that is has high gain about 80dB by sensing the very small current.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.2073-2076
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• 2010

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1485-1490
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• 2014

We have designed and developed a new ladder type tetrafused ${\pi}$-conjugated building block such as dihydroindolo[3,2-b]indole (DINI) and investigated its role as an electron rich unit. The photovoltaic properties of a new semiconducting ${\pi}$-conjugated polymer, poly[[5,10-bisoctyl-5,10-dihydroindolo[3,2-b]indole-[5,6- bis(octyloxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole]], represented by PDINI-OBTC8 are described. The new polymer PDINI-OBTC8 was synthesized in donor-acceptor (D-A) fashion, where fused ${\pi}$-conjugated tetracyclic DINI, and 5,6-bis(octyloxy)-4,7-di(thiophen-2-yl) benzo[c][1,2,5]thiadiazole (OBTC8) were employed as electron rich (donor) and electron deficient (acceptor) moieties, respectively. The conventional bulk heterojunction (BHJ) device structure ITO/PEDOT:PSS/PDINI-OBTC8:PCB71M/LiF/Al was utilized to fabricate polymer solar cells (PSCs), which comprises the blend of PDINI-OBTC8 and [6,6]-phenyl-$C_{71}$-butyric acid methyl ester ($PC_{71}BM$) in BHJ network. A BHJ PSC that contain PDINI-OBTC8 delivered power conversion efficiency (PCE) value of 1.68% with 1 vol% of 1,8-diidooctane (DIO) under the illumination of A.M 1.5G 100 $mW/cm^2$.

• Journal of Information Display
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• v.6 no.1
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• pp.33-36
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• 2005

To obtain various colors from the blue emitting poly(fluorene)s, two different approaches are introduced. One is copolymerization with low band gap comonomers and the other is molecular doping with various dyes. As fast and efficient exciton migration and trapping and/or energy transfer between the chromorphoric segments or doped dyes in conjugated polymers can shift the emission to longer wavelengths, these phenomena can be utilized to obtain various colors from the intrinsically blue light emitting poly(fluorene)s.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.263-266
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• 1999

Electrolunlinescent devices based on conjugated polymer emitting materials have been much attracted possible applications for multicolor flat panel display, since the conjugated polymers have a small band gap emitting obtained at a low driving voltage. In this paper, we fabricated the single layer EL device using poly(3-hexylthiophene) as emitting material Electroluminescence(EL) and I-V-L characteristics of indium-tin-oxide[ITO]P3HT/AI device with a various thickness were investigated. It was demonstrate that the I-V characteristics depend, not the voltage but the electric- field strength, The current is dependent on the electric filed and not on the applied voltage, indicating that the carriers are injected by a tunneling process. In the device, the barrier to hole injection is only 0.5eV and the barrier to electron injection is 1.5eV.