Research Institute for Electronic Science, Hokkaido University


LAST UPDATE 2021/06/07

  • 研究者氏名
    Researcher Name

    ビジュ・ヴァスデヴァン・ピライ BIJU Vasudevan Pillai
    教授 professor
  • 所属
    Professional Affiliation

    Research Institute for Electronic Science, Hokkaido University

    物質科学研究部門 分子フォトニクス研究分野
    Material and Molecular Sciences, Laboratory of Molecular Photonics
  • 研究キーワード
    Research Keywords

    Physical Chemistry
    Semiconductor Nanoparticles and Quantum Dots
    Electron and energy transfer
    Molecular Sensors
Research Subject

Fluorescent Nanomaterials, Quantum Dots, and Molecules

研究の背景 Background

Metal chalcogenide quantum dots and metal halide perovskite nanomaterials emerge as a promising and cost-effective class of semiconductors for next-generation photoluminescent, electroluminescent and photovoltaic devices. These nanomaterials own high optical absorption coefficients and narrow-band bright photoluminescence, which are in addition to the composition-and size-dependent tunable bandgap, exciton binding energy, and carrier diffusion. However, these materials show photobleaching or stochastic fluctuations in their luminescence due to electronics/ionic defects and photo-charging. Therefore, it is essential to classify the origins of the blinking and bleaching processes and develop high-quality quantum optical materials.

研究の目標 Outcome

Semiconductor quantum dots, nanocrystals, and microcrystals with stable photoluminescence and electroluminescence are developed by synthesizing these nanomaterials, analyzing their photoluminescence properties at the single-particle level, and passivating ionic and electronic defects. Random charging, blinking, and bleaching of metal chalcogenide quantum dots are suppressed by photoinduced electron transfer from molecular donors. Conversely, the photoluminescence and electroluminescence properties of halide perovskite quantum dots, nanocrystals, and microcrystals are optimized by real-time halide vacancy filling and light-soaking. Thus, by combining materials synthesis and optical studies with physicochemical modification of the structure and properties, this research develops highly luminescent semiconductor materials.

研究図Research Figure

Fig.1. MAPbI3 perovskite nanocrystals with photoluminescence stailized by the suppression of superoxide generation.

Fig.2. Bromide and iodide perovskite quantum dots with photoluminescence optimized by halide vacancy filling.

文献 / Publications

L. Chouhan, S. Ito, E. M. Thomas, Y. Takano, S. Ghimire, H. Miyasaka, V. Biju, ACS Nano 2021, 15, 2831.               E. M. Thomas, S. Ghimire, R. Kohara, A. N. Anil, K. Yuyama, Y. Takano, K. G. Thomas, V. Biju, ACS Nano 2018, 12, 9060.