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2017 Fiscal Year Annual Research Report

One and multiple photon induced generation and stabilization of multi-excitons in quantum dot superlattices

Publicly Offered Research

Project AreaApplication of Cooperative-Excitation into Innovative Molecular Systems with High-Order Photo-functions
Project/Area Number 17H05243
Research InstitutionHokkaido University

Principal Investigator

Biju V・Pillai  北海道大学, 電子科学研究所, 教授 (60392651)

Project Period (FY) 2017-04-01 – 2019-03-31
Keywordssuperlattice / quantum dots / perovskite / nanocrystal / charge migration / photoluminescence
Outline of Annual Research Achievements

This project focuses on the preparation of superlattices of semiconductor quantum dots and perovskite nanocrystals, which was followed by controlling density of photo-activated excitons by tuning the intensity of incident laser beam. Under low laser flounce, the photo -generated charge carriers were stabilized in the superlattice structures, providing carriers with microsecond lifetimes. However, in highly-excited superlattices, the lifetime was decreased to the nanosecond scale. Furthermore, the intensity of emitted photons increased exponentially with increase in the incident photon flux, suggesting that the highly-excited superlattices follow radiative relaxation. However, amplified stimulated emission was not detected, which can be due to random diffusion of charges in the film. Overall, this research validated the breaking of 1 nanocrystal, 1 photon, 1 exciton relation by controlling the excitation intensity dependent multiplication, pooling and diffusion of charge carriers.
This research expands to evaluate the roles of material composition, electron/hole defects, and the intensity and energy of excitation light on the diffusion and recombination of multiple charges in superlattices.

Unique outcomes of this research are twofold: (i) stable, long-lived charge carriers are generated by preparing self-assembled nanocrystal films of quantum dots and perovskites, and (ii) accomplished optical control of charge carrier density and their mode of recombination in nanocrystal assemblies.

Current Status of Research Progress
Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

Research activities are all precisely focused in the direction that was proposed initially. The results obtained are all satisfactory. Young researchers such as doctor course students are attracted to this research. To-date three PhD students work on this project, preparing novel 2D and 3D materials based on quantum dots and perovskites and piling up new, in-depth information about photo-induced dynamics of charge carriers in such materials. Furthermore, three new students approached me personally to join the research activities related to this project, showing that the outcome seeds new research themes in the perovskite/quantum dot based photophysics, with continued support from JSPS. Also, one doctor course student from Indian Institute of Science Education had joined this project as a visiting student, which was directly supported by the program leader, Prof. Hiroshi Miyasaka. In addition to the above members, one doctor course student from Indian Institute of Technology Hyderabad expressed interest in joining the lab and work on problems closely related to the project.
Collaborative research with this area continues with Prof. Tsukasa Torimoto of Nagoya University (Group A01) and Prof. Martin Vacha of Tokyo Institute of Technology (Group A03). My expectation is that the outcome of the research would extensively exceed than what was initially expected.

Strategy for Future Research Activity

One of the important remaining challenges in this project is extraction of evidence about the mechanism of long-range charge carrier migration in self-assembled nanocrystal films, which will be investigated in the remaining period. Also, it is essential to prove how carrier-carrier interactions in highly-excited superlattices lead to an exponential increase in the rate of radiative recombination. For these purposes, superlattices of nanocrystals with different band-gap materials will be prepared by controlling their assembly and order of arrangements. In such materials, the migration of charge carriers will be carried out through different energy states. Spectrally and temporally resolved photoluminescence measurements will be carried out to characterize the dynamics of diffusion and recombination of charge carriers in highly-excited superlattices. Also, spatially and temporally controlled experiments will be conducted to validate the relations among excitation, and exciton migration and recombination. Furthermore, transient absorption measurements will be carried out to understand the interactions of charge carriers with phonons while migrating from nanocrystals to nanocrystals.

  • Research Products

    (18 results)

All 2018 2017 Other

All Int'l Joint Research (1 results) Journal Article (6 results) (of which Int'l Joint Research: 6 results,  Peer Reviewed: 6 results) Presentation (11 results) (of which Int'l Joint Research: 6 results,  Invited: 6 results)

  • [Int'l Joint Research] IISER, Trivandrum(India)

    • Country Name
      India
    • Counterpart Institution
      IISER, Trivandrum
  • [Journal Article] Development of Technologies for Sensing Ozone in Ambient Air2018

    • Author(s)
      Masanori Ando, Vasudevan Pillai Biju, Yasushi Shigeri
    • Journal Title

      Analytical Sciences

      Volume: 34 Pages: 263-271

    • DOI

      10.2116/analsci.34.263

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Quantum Dot-Peptide Nanoassembly on Mesoporous Silica Nanoparticle for Biosensing2018

    • Author(s)
      Sasidharan Pillai Sreenadh, Hiroshi Yukawa, Daisuke Onoshima, Vasudevanpillai Biju, Yoshinobu Baba
    • Journal Title

      Nano Hybrids and Composites

      Volume: 19 Pages: 55-72

    • DOI

      10.4028/www.scientific.net/NHC.19

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Relations of exciton dynamics in quantum dots to photoluminescence, lasing, and energy harvesting2018

    • Author(s)
      Sushant Ghimire, Vasudevanpillai Biju
    • Journal Title

      Journal of Photochemistry and Photobiology C

      Volume: 37 Pages: 137-151

    • DOI

      10.1016/j.jphotochemrev.2018.01.004

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] In vivo ROS production and use of oxidative stress-derived biomarkers to detect the onset of diseases such as Alzheimer's disease, Parkinson's disease, and diabetes.2017

    • Author(s)
      Aya Umeno, Vasudevanpillai Biju, Yasukazu Yoshida
    • Journal Title

      Free Radical Research

      Volume: 51 Pages: 413-427

    • DOI

      10.1080/10715762.2017.1315114

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Blue‐Emitting Electron‐Donor/Acceptor Dyads for Naked‐Eye Fluorescence Detection of Singlet Oxygen2017

    • Author(s)
      Reiko Kohara, Ken‐ichi Yuyama, Yasushi Shigeri, Vasudevanpillai Biju
    • Journal Title

      ChemPhotoChem

      Volume: 1 Pages: 299-303

    • DOI

      10.1002/cptc.201700046

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Reversible photoluminescence sensing of gaseous alkylamines using CdSe-based quantum dots2017

    • Author(s)
      Masanori Ando, Takuya Kamimura, Koichi Uegaki, Vasudevanpillai Biju, Jennifer T Damasco Ty, Yasushi Shigeri
    • Journal Title

      Sensors and Actuators B: Chemical

      Volume: 246 Pages: 1074-1079

    • DOI

      10.1016/j.snb.2017.01.058

    • Peer Reviewed / Int'l Joint Research
  • [Presentation] Extended Diffusion of Charge Carriers in Perovskite Nanocrystal Assembly2018

    • Author(s)
      Sushant GHIMIRE, Lata CHOUHAN, Kenichi YUYAMA, Yuta TAKANO, Vasudevanpillai Biju
    • Organizer
      日本化学会第98春季年会2018
  • [Presentation] A Few Intracellular Pathways Of Quantum Dot Bioconjugates2017

    • Author(s)
      Vasudevanpillai Biju
    • Organizer
      MAF2017
    • Int'l Joint Research / Invited
  • [Presentation] Single molecule detections &Bioimaging using Semiconductor Nanocrystals.2017

    • Author(s)
      Vasudevanpillai Biju
    • Organizer
      Emerging Frontiers in Chemical Science 2017
    • Int'l Joint Research / Invited
  • [Presentation] Quantum Dots for Single Molecule Detections: Recent Progress and Challenges2017

    • Author(s)
      Vasudevanpillai Biju
    • Organizer
      2017 RIES-CIS Symposium
    • Int'l Joint Research / Invited
  • [Presentation] Semiconductor Quantum Dots in Single Molecule Detections: Prospects and challenges2017

    • Author(s)
      Vasudevanpillai Biju
    • Organizer
      ICPA
    • Int'l Joint Research / Invited
  • [Presentation] Semiconductore Quantum Dots for Single-molecule Detections in Living Cells: Challenges and Progress2017

    • Author(s)
      Vasudevanpillai Biju
    • Organizer
      Nanobiotechnology
    • Int'l Joint Research / Invited
  • [Presentation] Semiconductor Quontum Dots in Bioimagion: Progress and Challenges2017

    • Author(s)
      Vasudevanpillai Biju
    • Organizer
      9th Bangalore India NANO
    • Int'l Joint Research / Invited
  • [Presentation] Fluorescence Detection of Singlet Oxygen Using Intramolecular Electron Donor-Acceptor Dyads2017

    • Author(s)
      Reiko Kohara, Kenichi Yuyama, Vasudevanpillai Biju
    • Organizer
      2017年光化学討論会
  • [Presentation] 界面での半導体ナノ材料の光トラッピング2017

    • Author(s)
      Kenichi YUYAMA, Vasudevanpillai Biju
    • Organizer
      2017年光化学討論会
  • [Presentation] The Dynamics of Photogenerated Charge Carriers in Self-Assembled Semiconductor Nanocrystal Structures2017

    • Author(s)
      Sushant Ghimire, Vijayakumar C. Nair, Kenichi Yuyama, Vasudevanpillai Biju
    • Organizer
      The 18th RIES-Hokudai International Symposium
  • [Presentation] Electron Donor-Acceptor Dyads for Singlet Oxygen Detection: Oxidation vs Dimerization2017

    • Author(s)
      Reiko Kohara, Kenichi Yuyama, Vasudevanpillai Biju
    • Organizer
      The 18th RIES-Hokudai International Symposium

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Published: 2018-12-17  

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