Division of Materials Science, NAIST

Organic Electronics Laboratory

Staff & Contact
Educational StaffProf. Masakazu Nakamura
Associate Prof. Hiroaki Benten
Assistant Prof. Hirotaka Kojima, Jung Min-Chel
URLhttps://mswebs.naist.jp/LABs/greendevice/index_e.html

Let’s imagine electronic equipment that is easy to carry in a rolled state, a piece of fabric that generates electricity from the human body or a paper-like solar cell that generates electricity from light. Adding such unprecedented electronic functions onto various “surfaces”, human life will become more comfortable and prosperous. We are pursuing the realization of such novel electronic devices through studies elucidating unique phenomena in organic solids and applying the findings to the device functions using knowledge of solid-state physics, electronics, surface science, polymer physics, and molecular science. Our laboratory utilizes unique approaches made possible by our original characterization tools and computer simulations.

We determine individual research projects ranging from basic science to development of operable devices, depending on the interests and aptitudes of the students. We foster independent thinking and a top-level mindset necessary for a researcher through collaborative research with institutes in Japan and overseas. Thus, we aim to cultivate researchers with a broad knowledge of science and a keen interest toward industrial applications.

We are attempting to create novel thermoelectric materials and innovative flexible thermoelectric generators to convert exhaust heat from the living environment and the human body into electricity. We have found that the thermal conductivity of a carbon nanotube composite decreases to 1/1000 by forming molecular junctions between nanotubes with a specially designed protein. (Fig. 1) We are also trying to elucidate and control the Giant Seebeck Effect in organic semiconductors discovered in our laboratory (Fig. 2) with the aid of advanced measurement techniques, theoretical physics, and computational chemistry.

We develop original characterization techniques, such as AFM Potentiometry, and perform studies to deepen understanding of the structure and the electronic functions of organic semiconductors.

We develop next-generation solar cells based on semiconducting polymers. To elucidate the mechanisms that lead to photon-to-current energy conversion, functional structures of the photovoltaic layer have been visualized at the nanometer scale by conductive atomic force microscopy. (Fig. 3)

We study the origin of the strong absorption of terahertz wave by organic-inorganic hybrid perovskite thin film such as AMX3 (A = MA or FA, M = Pb or Sn, and X = Cl, Br, I) and develop THz-sensing devices with them. (Fig. 4)

  • Fig. 1 A novel design of a thermoelectric nanocomposite using biomolecular junctions
  • Fig. 2 Conceptual diagram of the Giant Seebeck Effect: a specific current-heat flow interaction in organic solids
  • Fig. 3 Functional structures for photovoltaic conversion in plastic solar cells
  • Fig. 4 An image of a baggage check with the rollable THz-wave imaging device

1.H. Kojima et al., “Universality of Giant Seebeck Effect in Organic Small Molecules”, Mater. Chem. Front. 2, 1276 (2018).
2.M. Ito, et al., “From materials to device design of a thermoelectric fabric for wearable energy harvesters”, J. Mater. Chem. A 5, 12068 (2017).
3.H. Benten et al., “Recent Research Progress of Polymer Donor/Polymer Acceptor Blend Solar Cells”, J. Mater. Chem. A 4, 5340 (2016).
4.Y. M. Lee, et al., “Surface Instability of Sn-based Hybrid Perovskite Thin Film, CH3NH3SnI3: The Origin of Its Material Instability”, J. Phys. Chem. Lett. 9, 2293 (2018).
5.M.-C. Jung, et al., “Diffusion and influence on photovoltaic characteristics of p-type dopants in organic photovoltaics for energy harvesting from blue-light”, Organic Electronics 52, 17 (2018).

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