Ryota Kabe

Okinawa Institute of Science and Technology Graduate University (OIST) Organic Optoelectronics Unit
Associate professor

Research AreasOrganic optoelectronics, Coordination Chemistry
Participating Group (2018-2019)

Controlling photo-induced charge-separation and emission from charge-recombination processes using soft crystals

Organic long persistent luminescence, Soft Crystal, Charge separation, Charge recombination, Exciplex

Research Outline

Most long persistent luminescent (LPL) materials, which slowly release energy absorbed from ambient light, are based on inorganic compounds. Organic long persistent luminescent (OLPL) systems have advantages over inorganic LPL materials of solubility, transparency, and flexibility. OLPL emission is based on successive processes of photo-induced charge-separation, charge diffusion, and emission form charge recombination. However, the LPL duration is still short because of inefficient charge-separation. Moreover, the OLPL has not been observed in air because of oxygen quenching. In this study, we develop a novel OLPL system based on a soft crystal strategy. We expect longer emission duration and air-stability because the soft crystal provides longer carrier diffusion lengths and denser molecular packing. Moreover, the optical properties will be controlled by application of electrical fields, thermal energy and mechanical forces to the soft crystal.

Emission mechanism of OLPL
Soft crystal OLPL system


Academic papers/reviewed


  1. "Fabrication-Method Independence of Organic Long-Persistent Luminescence Performance" K. Jinnai, N. Nishimura, R. Kabe, C. Adachi, Chem. Lett., 2019, 48, 270-273.
  2. "Organic Long-Persistent Luminescence from a Flexible and Transparent Doped Polymer" K. Jinnai, R. Kabe, C. Adachi, Advance Materials, 2018, 30, 1870286.
  3. "Wide-Range Tuning and Enhancement of Organic Long-Persistent Luminescence Using Emitter Dopants" Z. Lin, R. Kabe, N. Nishimura, K. Jinnai, C. Adachi, Adv. Mat., 2018, 30, 1800365.(Frontispiece)

Award winner


  1. " Orange Organic Long-persistent Luminescence from ally excited states on organic long persistence luminescence" Z. Lin, *R. Kabe, K. Wang, *C. Adachi, Nat. Commun. 11, 191 (2020).
  2. "Orange Organic Long-persistent Luminescence from an Electron Donor/Acceptor Binary System" Z. Lin, *R. Kabe, *C. Adachi, Chem. Lett., 49, 203–206 (2020).
  3. "Many Exciplex Systems Exhibit Organic Long-Persistent Luminescence" N. Nishimura, Z. Lin, K. Jinnai, *R. Kabe, *C. Adachi, Adv. Funct. Mater, 30, 2000795 (2020). (Inside back cover)

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