Kawakami Laboratory(Optoelectronic Materials Science and Engineering)
Department of Electronic Science and Engineering, Kyoto University
Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan
Welcome to Kawakami laboratory!

In the laboratory of Prof. Kawakami we study the interaction between light and matter; we try to elucidate and possibly discover physics involved in the interaction processes. We promote such studies to finally realize cutting-edge optical devices and applications that dramatically enrich human activities. Three main research lines are pursued:
(1) The development of new measurement techniques for studying nano-scaled optical emission dynamics
(2) The application of the original techniques developed in (1) to nano- and micro-scopic physical properties of materials and biosamples. New biosensors and devices are studied and realized.
(3) We also realized methodologies to modify and control the growth process of crystal structures of optical devices in order to obtain a light source with a desired emission color and a 100% quantum efficiency.
The synthesis of a desired optical spectrum is of course related to the realization of tailor-made solid-state optical devices. The topics in (1) and (2) are naturally linked each other and they both connect to the research line (3). In other words, the development of new materials and the study of their basic optical and physical properties give us a positive feedback on the realization of new devices, applications, and original measurement techniques.
As an application of optical materials, we can suggest bio and medical systems. In the near future we hope to realize micro-machinery able to enter the human body and perform measurements or actions, as was inspired by the 1966 Science Fiction movie "Fantastic Voyage". Our researches point toward the realization of smaller and higher-definition light sources and detection devices that are indispensable elements in such enterprise. Recently we were able to control the spectral emission of optical devices through special growth techniques. This is also promising for the final realization of extremely small light sources that can be used for insertion in the human body.
Finally, we want to understand the basic optical processes related to solid state illumination, for the realization of a new kind of illumination systems. We are pursuing the realization of nanometer sized light sources, highly efficient portable illumination element and optical devices of wide and controllable spectral characteristics. We are involved in this challenging endeavor in the hope to realize novel systems for both medical and technological applications.


  • The paper published in Applied Physics Express Vol. 6, No. 11, 111002 (2013) entitled
    "Remarkably Suppressed Luminescence Inhomogeneity in a (0001) InGaN Green Laser Structure"
    was scored first place in number of monthly downloaded articles of October 2013,
    and selected in the Editors' Choice of Applied Physics Express.
  • The paper talked at CLEO-PR&OECC/PS 2013 entitled
    "Local Photoluminescence Properties of InGaN Green Laser Structure on (0001) GaN Substrate"
    was selected in the Best Paper Awards.
  • The paper published in rapid communication of Physical Review B Vol. 87, No. 16, paper #161204(R) (2013) entitled
    "Huge electron-hole exchange interaction in aluminum nitride"
    was selected in the Editors' suggestions of Physical Review B.
  • The paper published in rapid communication of Physical Review B Vol. 87, No. 4, paper #041306(R) (2013) entitled
    "Strong optical polarization in nonpolar (1-100) AlGaN/AlN quantum wells"
    was selected in the Editors' suggestions of Physical Review B.
  • "100 mW deep-ultraviolet emission from aluminium-nitride-based quantum wells pumped by an electron beam"
    was published in the Nature Photonics (2010).
  • The paper published in Nature Photonics Vol. 4, No. 11, pp. 767-770, (2010) entitled
    "100 mW deep-ultraviolet emission from aluminium-nitride-based quantum wells pumped by an electron beam"
    was introduced in the Research Highlights of Nature asia-pacific Materials.
  • "Visualization of the Local Carrier Dynamics in an InGaN Quantum Well Using Dual-Probe Scanning Near-Field Optical Microsocpy"
    was published in the Appl. Phys. Express 3, 102102 (2010)
  • Profs. M. Funato and Y. Kawakami
    "Semipolar III Nitride Semiconductors: Crystal Growth, Device Fabrication, and Optical Anisotropy"
    was published in the Materials Research Society (MRS) Bulletin Vol.34, No.5, pp.334-340, (2009).
  • The paper published in Appl. Phys. Exp. 1, 011106 (2008) entitled
    "Monolithic Polychromatic Light-Emitting Diodes Based on InGaN Microfacet Quantum Wells toward Tailor-Made Solid-State Lighting"
    was introduced in the Research Highlights of Nature Photonics.
    Nature Photonics vol.2, p.128 (March 2008)
  • Profs. Y. Kawakami and M. Funato
    Realization of phosphor free polychromatic LEDs. The LEDs emitting multiple colors including white were realized in collaboration with Dr. Yukio Narukawa and Dr. Takashi Mukai of Nichia Corp. Japan.
    Details are described in Appl. Phys. Express 1, 011106 (2008)

    This topic appeared in many Japanese newspapers, and was broadcasted by the Japanese National TV (NHK).

    This topic introduced in the related articles:
    Trend in Japan
    "Broadening The LED Color Spectrum" New Diode Can Produce White and Intermediate Colors
    SPIE Newsroom
    "Light-emitting diode design allows precise control of colors and intensity"
    Compound Semiconductor, vol.15, No.5, p.14
    "Multi-faced LEDs introduce more color"

  • Profs. Y. Kawakami, M. Funato and Dr. A. Kaneta
    "Assessment and Modification of Recombination Dynamics in InxGa1-xN-Based Quantum Wells"
    was published in the Materials Science Forum Vol.590 (2008), Advances in Light Emitting Materials
Invited talks