Research Subjects

• Fabrication of well-defined organic and polymer nanocrystals, and their size-dependent optoelectronic properties.
• Developments of novel fabrication processes for organic-inorganic (metal, oxides) hybridized nanocrystals, and their synergistic effect between organics and metal in nonlinear optics.
• Building of ordered array nanostructures consisted of transparent polymer microspheres and/or polymer-encapsulated organic nanocrystals, and their light propagation behaviors.
• Structural control of 3-dimensional ordered microporous (3DOM) materials, and their application to photonic materials and low-k materials.
• Conductive electronic properties of surface-doped conjugated polymers thin films.
• Random lasing behaviors from porous nanostructure medium.
• Electric and optoelectronic properties of doped charge transfer complex nanocrystals.

Overview of Research

Fabrication of Organic and Polymer Hybridized Nanocrystals and Their Optoelectronic Function
π-Conjugated organic crystals exhibit excellent optoelectronic and photonic properties, depending on morphology. The device applications, however, will be often involved in intrinsic problems on processability. As approaches to overcome these problems, we have succeeded in nanocrystallization of organic compounds by the useful reprecipitation method, and fabricated transparent layer-by-layer films and polymer composites containing the organic nanocrystals. On the other hand, orientational and positional control of individual polymer particles could be achieved by applying an external field and on a patterned substrate for practical devices application. Furthermore, we also recently started fabricating hybridized nanocrystals, consisting of organics and metal, as a novel material. Since the dimension and structure of hybridized nanomaterials would definitely determine the physicochemical properties such as nonlinear optical properties and photoelectric conversion, it becomes so important to develop fabrication technique, and characterize the hybridized nanostructures in detail.

Selected Publications

• Encapsulation of π-Conjugated Polymer Nanocrystals and Ordered Array Structure toward Photonic Nanomaterials T. Onodera, M. Nakamura, Y. Takaya, A. Masuhara, Y. Wakayama, N. Nemoto, H. Nakanishi, and H. Oikawa: J. Phys. Chem. C, 113, 11647-11651 (2009).
• Micro-Demultiplexer of Coupled Resonator Optical Waveguide Fabricated by Microspheres T. Mitsui, Y. Wakayama, T. Onodera, T. Hayashi, N. Ikeda, Y. Sugimoto, T. Takamasu, and H. Oikawa: Adv. Mater., 22, 3022-3026 (2010).
• Silver Nanoparticle-Accelerated Photopolymerization of a Diacetylene Derivative T. Yokoyama, A. Masuhara, T. Onodera, H. Kasai, and H. Oikawa: J. Phys. Chem. C, 115, 22121-22125 (2011).
• Fabrication of Doped Cu-TCNQ Nanocrystals and Their Optoelectronic Properties T. Onodera, S. Matsuo, K. Hiraishi, A. Masuhara, H. Kasai, and H. Oikawa: CrystEngComm,14, 7586-7589 (2012).
• Highly Controlled Plasmonic Emission Enhancement from Novel Metal-Semiconductor Quantum Dots Complex Nanostructures H. Naiki, A. Masuhara, S. Masuo, T. Onodera, H. Kasai, and H. Oikawa: J. Phys. Chem., C, 117, 2455-2459 (2013).
• Fabrication of Fluorescent Copper Complex Nanoparticles Using the Heterogeneous Reaction Process R. Suzuki, T. Onodera, H. Kasai, and H. Oikawa: Jpn. J. Appl. Phys., 53, 06JH03-1-4 (2014).
• Nanocrystallization of Insoluble Copper(I) Complex and Formation Mechanism R. Suzuki, T. Onodera, H. Kasai, and H. Oikawa: Mol. Cryst. Liq. Cryst., 621, 150-155 (2015).
• Giant Amplification of Photoswitching by a Few Photons in Fluorescent Photochromic Organic Nanoparticles J. Su, T. Fukaminato, J.-P. Placial, T. Onodera, R. Suzuki, H. Oikawa, A. Brosseau, F. Brisset, R. Pansu, K. Nakatani, and R. Métivier: Angew. Chem. Int. Ed., 55, 3662-3666 (2016).
• Highly Enhanced Emission of Visible Light from Core-Dual Shell Type Hybridized Nanoparticle N. Sakamoto, T. Onodera, T. Dezawa, Y. Shibata, and H. Oikawa: Part. Part. Syst. Char., 34, 1700258 1-5 (2017).
• A Promising Visible-Light-Driven Photocatalytic Activity of Conjugated Polymer Nanocrystals C. Pornrungroj, M. Ozawa, T. Onodera, and H. Oikawa: RSC Adv., 8, 38773-38779 (2018).

Contact Information

Please delete “/” after “@” in a mail address.
Hidetoshi OIKAWA
(TEL +81-22-217-6357, Email: oikawah@/tagen.tohoku.ac.jp)
Tsunenobu ONODERA
(TEL +81-22-217-5645, Email: onoderat@/tagen.tohoku.ac.jp)
FAX +81-22-217-5645