著者

Hiroki Nagashima Shuhei Kawaoka Yasunori Matsui Takashi Tachikawa Hiroshi Ikeda Yasuhiro Kobori

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.31, no.2, pp.163-167, 2018-06-25 (Released:2018-09-05)

参考文献数

26

被引用文献数

1

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The singlet fission (SF) is expected to be powerful tool for exceeding the theoretical limit of the power conversion efficiency on the organic solar cells. However, little is known on the intermolecular SF mechanism in the solid state. In the present study, we have investigated intermolecular SF in 2-phenyl-6,11-bis(triisopropylsilylethynyl)tetracene (TIPS-Ph-Tc) in frozen solutions using a time-resolved electron paramagnetic resonance measurement at a low temperature. SF-born quintet states (Q) and subsequent dissociations into two triplet states (T + T) were detected for a diluted solute concentration of 10-4 M in dichloromethane. The microsecond triplet dissociation was found to occur due to the amorphous morphology in the frozen aggregate, suggesting that Q is generated as a trapped state. Furthermore, it was also suggested that the T + T dissociation follows the Q generation due to a T-T repulsion, whose energy were determined by the negative exchange couplings in the triplet pairs, (TT).

著者

Kazuki Okamoto Tomohito Wakasa Jun Taniguchi Shin-ichi Satake

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.35, no.2, pp.125-130, 2022-12-16 (Released:2023-03-14)

参考文献数

20

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Performing the minimum number of ultraviolet nanoimprint lithography imprints is important for ensuring high throughput and low costs. The stamp lifetime can be estimated quickly from little information during imprint processing. We proposed two methods to predict the stamp lifetime from durability test data with a line-patterned mold. We characterized the contact angle, concentration of release resin, and the number of imprints from the data. Both of the proposed methods used machine learning. One method was binary classification, and the other was regression analysis. Under the binary classification method, the recall was 50% and the prediction showed that the recall becomes 0% when Gaussian random noise is added. Under the regression analysis, the prediction did not drastically change, with an approximately 100-fold increase in the mean absolute error. The results show that regression analysis is useful for predicting the lifetime of a line-patterned mold.

著者

Hitoshi Sugiyama Shuichi Sato Kazukiyo Nagai

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.34, no.6, pp.571-578, 2021 (Released:2022-08-10)

参考文献数

22

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The photo-alignment properties of 4,4-(hexafluoroisopropylidene) diphthalic anhydride (6FDA)-based polyimides with sterically hindered diamine component were systematically evaluated, such as 6FDA-3,3'-dimethylbenidine, 6FDA-2,7-diaminofluorene, 6FDA- 2,3,5,6-tetramethyl-1,4-phenylene diamine, 6FDA-2,5-diamino-1,4-phenylenediamine, 6FDA-1,4-phenylenediamine, and 6FDA-1,3-phenylenediamine. To evaluate sterically hindered diamine components, the diamine components with varying number of benzyl ring and methyl group were used. The polyimides containing the diamine components with methyl group were well planarity and forming charge transfer complex efficiently. The polyimides showing photo reaction property by linearly polarized ultra violet light induced photo alignment properties, however, the linear structured polyimide induced photo alignment property even it showed poor photo reaction property.

著者

Jin-Kyun Lee Priscillia G. Taylor Alexander A. Zakhidov Hon Hang Fong Ha Soo Hwang Margarita Chatzichristidi George G. Malliaras Christopher K. Ober

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.22, no.5, pp.565-569, 2009-06-30 (Released:2009-09-17)

参考文献数

21

被引用文献数

23 24

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Organic electronics is an extensively studied subject opening new horizons in electronics technology. It has attracted great attention as a technology to enable flexible electronic devices through solution processing of organic and polymeric materials. However, patterning of organic materials to construct device components still remains one of the major hurdles to be overcome due to problems with chemical processing. Fundamentally this challenge originates from the limited number of options regarding orthogonal solvents. Recently, we have identified supercritical carbon dioxide (scCO2) and segregated hydrofluoroethers (HFEs) as universal, non-damaging solvents for most non-fluorinated polymeric materials. These unconventional solvents expand processing options from the two-dimensional plane to three-dimensional space by drawing another orthogonal axis. Taking advantage of those noble solvents and fluorinated photoresists, we were able to make patterns of functional organic materials photolithographically. Furthermore, our orthogonal processing method has been applied to the fabrication of a patterned polymer light-emitting device in scCO2 and an organic thin-film transisotor in HFEs.

著者

Masayoshi Higuchi Yukio Fujii

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.34, no.2, pp.175-180, 2021-06-11 (Released:2021-11-23)

参考文献数

20

被引用文献数

3

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Electrochromic (EC) displays are expected as energy-saving smart windows or digital signages because of the memory property. We succeeded in developing a designed and flexible electrochromic (EC) display device with Fe(II)-based metallo-supramolecular polymer (polyFe) using a mechanically etched ITO film. Mechanical etching an ITO film was performed with a cutting machine having a blade of which length was adjusted so as not to cut off the film. The fabricated EC device was composed of the etched ITO film, a polyFe layer, an electrolyte layer, a nickel hexacyanoferrate layer as the counter material, and another ITO film. The EC device showed unique changes of the display upon applying a voltage of 1.5 V between the two ITO electrodes. It was revealed that the EC changes were controlled by the etching pattern such as a closed circle or the formation of a narrow ITO path.

著者

Shengjie Fang Masakazu Umezawa Kyohei Okubo Kohei Soga

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.34, no.1, pp.7-10, 2021-06-11 (Released:2021-11-23)

参考文献数

26

被引用文献数

1

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Near-infrared (NIR) light has been used for in vivo deep imaging in the biomedical field owing to its high permeability in biological tissues. Conventional fluorescence bioimaging requires simultaneous optical excitation, which can induce undesired results such as autofluorescence. In the present study, we report a polymer-based NIR afterglow fluorescent complex by using NIR dye, LDS 821, and SrAl2O4: Eu, Dy powder. To obtain the complex, SrAl2O4: Eu, Dy was first mixed with LDS 821 solution and dried at 65 °C for 12 h. Then, they were further mixed with pentaerythiritol tetraacrylate (PETA) and photopolymerization initiator and then subjected to phopolymerization reaction. Poly-PETA was effective for not only retain both the dye and inorganic powder but also preventing the denaturation of SrAl2O4: Eu, Dy by water. The obtained polymer-based complex emits NIR afterglow fluorescence (wavelength: 760−780 nm) with a long fluorescence lifetime (5.0 min). This material design will provide a choice of obtaining NIR luminescent imaging phosphors for deep tissues without simultaneous light irradiation during image acquisition.

著者

Syo Miyagi Takuya Kusanagi Shuichi Sato

出版者

The Society of Photopolymer Science and Technology(SPST)

雑誌

Journal of Photopolymer Science and Technology (ISSN:09149244)

巻号頁・発行日

vol.32, no.1, pp.33-43, 2019-06-24 (Released:2019-11-14)

参考文献数

20

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The effects of polymer gel electrolyte on the photoelectric and driving characteristics of Prussian blue (PB)-based electrochromic (EC) cells were systematically investigated under different preparation conditions. The EC cells were switched from the coloring to decoloring mode by applying ±1.5 V. Subsequently, we prepared an automatic driving circuit wherein the signal of the voltage was alternately applied. The thickness of the PB layer significantly depended on the switching speed as opposed to the electrolyte concentration and the polymer gel electrolyte. In particular, the speed of coloring exceeds that of decoloring due to the electron exchange in the chemical reaction. The speed varied from approximately 5 to 10 times based on the type of the electrolyte.