Enhanced molecular emission characteristics by controlling electronic structure relating to the high order singlet excited state

• Project/Area Number: 18H02046
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: The University of Electro-Communications
• Principal Investigator: Hirata Shuzo 電気通信大学, 大学院情報理工学研究科, 准教授 (20552227)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥17,030,000 (Direct Cost: ¥13,100,000、Indirect Cost: ¥3,930,000); Fiscal Year 2020: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2019: ¥10,140,000 (Direct Cost: ¥7,800,000、Indirect Cost: ¥2,340,000); Fiscal Year 2018: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
• Keywords: 高次一重項励起状態 / 2光子吸収 / 光アップコンバージョン / 室温りん光 / 長寿命室温りん光 / 蓄光 / 三重項励起状態 / スピン軌道相互作用 / Kasha則 / 非放射遷移 / Kashaの法則 / 内部項間 / 分子軌道 / 高次励起状態 / 励起吸収 / 2段階励起

Outline of Final Research Achievements

Electronic structures relating to the high order singlet excited state (Sn) have not been considered to control excitons. Here we enhance photon up-conversion characteristics via two-photon absorption and persistent room-temperature phosphorescence (RTP) characteristics by controlling the electronic structures relating to Sn. The effective separation between electronic structures relating to Sn and that relating to the lowest singlet excited state led to more fluorescence from Sn to allow enhanced photon-up conversion intensity after stepwise two-photon absorption. The enhancement of the transition dipole moment between Sn and the ground state by controlling the Sn electronic structure increases the rate constant of phosphorescence without largely increasing the rate constant of nonradiative transition from the lowest triplet excited state, resulting in a large increase of RTP yield with keeping long RTP lifetime.

Academic Significance and Societal Importance of the Research Achievements

生体イメージング用の発光分子プローブでは、個々の分子が分子レベルで反応に作用する必要があるが、逐次型2光子吸収によって光アップコンバージョンを示す分子はより小型な低パワーナノ秒光源での3次元発光イメージングを可能にする技術につながる可能性がある。また高効率長寿命室温りん光分子の既存の蓄光材料、化学発光材料、放射線材料と比較して瞬間的につよい残光の輝度を出す特性は、既存の材料や技術では困難であった高解像イメージングと自家蛍光フリーを両立する非接触イメージング技術領域を開拓することにつながることが期待される。

Research Products

• [Journal Article] Key of Suppressed Triplet Nonradiative Transition-Dependent Chemical Backbone for Spatial Self-Tunable Afterglow (2021)
  • Author(s): Indranil Bhattacharjee, Kikuya Hayashi, Shuzo Hirata*
  • Journal Title: JACS Au Volume: in press
  • Peer Reviewed / Open Access
• [Journal Article] Chiral Approach to Investigate Mechanism of Highly Efficient Thermally Activated Delayed Fluorescence (2021)
  • Author(s): Kikuya Hayashi, Arimasa Matsumoto, Shuzo Hirata*
  • Journal Title: Chemical Communications Volume: 57 Issue: 14 Pages: 1738-1741
  • DOI: 10.1039/d0cc08064k
  • Peer Reviewed
• [Journal Article] Vibrational Radiationless Transition from Triplet States of Chromophores at Room Temperature (2021)
  • Author(s): Shuzo Hirata*, Indranil Bhattacharjee
  • Journal Title: The Journal of Physical Chemistry A Volume: 125 Issue: 3 Pages: 885-894
  • DOI: 10.1021/acs.jpca.0c09410
  • Peer Reviewed
• [Journal Article] Phosphorescence Quenching of Heavy-atom-free Dopant Chromophores Triggered by Thermally Activated Triplet Exciton Diffusion of Conjugated Crystalline Host (2020)
  • Author(s): Shuzo Hirata*, Hyuman Hara, Indranil Bhattacharjee
  • Journal Title: The Journal of Physical Chemistry C Volume: 124 Issue: 45 Pages: 25121-25132
  • DOI: 10.1021/acs.jpcc.0c07864
  • Peer Reviewed
• [Journal Article] The Substituent-Induced Symmetry-Forbidden Electronic Transition Allows Significant Optical Limiting under Weak Sky-Blue Irradiance (2020)
  • Author(s): Takuya Kamatsuki, Indranil Bhattacharjee,* and Shuzo Hirata*
  • Journal Title: The Journal of Physical Chemistry Letters Volume: 11 Issue: 20 Pages: 8675-8681
  • DOI: 10.1021/acs.jpclett.0c02694
  • Peer Reviewed
• [Journal Article] Highly efficient persistent room-temperature phosphorescence from heavy atom-free molecules triggered by hidden long phosphorescent antenna (2020)
  • Author(s): Indranil, Bhattacharjee, Shuzo Hirata*
  • Journal Title: Advanced Materials Volume: 32 Issue: 31 Pages: 2001348-2001348
  • DOI: 10.1002/adma.202001348
  • Peer Reviewed / Open Access
• [Journal Article] Energy localization vs. charge funneling in aggregates of CsPbBr3 perovskite nanocrystals (2020)
  • Author(s): Dharmendar Kumar Sharma*, Shuzo Hirata, Martin Vacha*
  • Journal Title: Journal of Luminescence Volume: 222 Pages: 117119-117119
  • DOI: 10.1016/j.jlumin.2020.117119
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effect of Tris(trimethylsilyl)silyl Group on the Fluorescence and Triplet Yields of Oligothiophenes (2020)
  • Author(s): Hirata, S.;* Nishio, M.; Uchida, H.; Usuki, T.; Nakae, T.; Miyachi, M.; Yamanoi, Y.;* Nishihara, H.*
  • Journal Title: J. Phys. Chem. C Volume: 124 Issue: 5 Pages: 3277-3286
  • DOI: 10.1021/acs.jpcc.9b10718
  • Peer Reviewed
• [Journal Article] Single-particle electroluminescence of CsPbBr3 perovskite nanocrystals reveals particle-selective recombination and blinking as key efficiency factors (2019)
  • Author(s): Dharmendar Kumar Sharma*, Shuzo Hirata, Martin Vacha*
  • Journal Title: Nature Communications Volume: 10 Issue: 1 Pages: 4499-4499
  • DOI: 10.1038/s41467-019-12512-y
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Roles of Localized Electronic Structures caused by π Degeneracy due to Highly Symmetric Heavy Atom-free Conjugated Molecular Crystals leading to Efficient Persistent Room-temperature Phosphorescence (2019)
  • Author(s): Shuzo Hirata
  • Journal Title: Advanced Science Volume: 6 Pages: 1900410-1900410
  • Peer Reviewed / Open Access
• [Journal Article] Suppressed Triplet Exciton Diffusion Due to Small Orbital Overlap as a Key Design Factor for Ultralong‐Lived Room‐Temperature Phosphorescence in Molecular Crystals (2019)
  • Author(s): Kaishi Narushima, Yasuhiro Kiyota, Takehiko Mori, Shuzo Hirata, Martin Vacha
  • Journal Title: Advanced Materials Volume: 31 Issue: 10 Pages: 1807268-1807268
  • DOI: 10.1002/adma.201807268
  • Peer Reviewed
• [Journal Article] Stark Effect and Environment Induced Modulation of Emission in Single Halide Perovskite Nanocrystals (2019)
  • Author(s): Dharmendar Kumar Sharma, Shuzo Hirata, Vasudevanpillai Biju, Martin Vacha
  • Journal Title: ACS nano Volume: 13 Issue: 1 Pages: 624-632
  • DOI: 10.1021/acsnano.8b07677
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] A Colorless Semi-aromatic Polyimide Derived from a Sterically Hindered Bromine-Substituted Dianhydride Exhibiting Dual Fluorescent and Phosphorescent Emission (2019)
  • Author(s): Kenta Kanosue, Shuzo Hirata, Martin Vacha, Ramunas Augulis, Vidmantas Gulbinas, Ryohei Ishige, Shinji Ando
  • Journal Title: Materials Chemistry Frontier Volume: 3 Issue: 1 Pages: 39-49
  • DOI: 10.1039/c8qm00409a
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Wavelength-Tunable Band-Edge Photoluminescence of Nonstoichiometric Ag-In-S Nanoparticles via Ga3+ Doping (2018)
  • Author(s): Tatsuya Kameyama, Marino Kishi, Chie Miyamae, Dharmendar Kumar Sharma, Shuzo Hirata, Takahisa Yamamoto, Taro Uematsu, Martin Vacha, Susumu Kuwabata, and Tsukasa Torimoto
  • Journal Title: ACS Applied Mater. Interfaces Volume: 10 Issue: 49 Pages: 42844-42855
  • DOI: 10.1021/acsami.8b15222
  • Peer Reviewed / Open Access
• [Journal Article] dentification of Short- and Long-Wavelength Emitting Chlorophylls in Cyanobacterial Photosystem I by Plasmon-Enhanced Single-Particle Spectroscopy at Room Temperature (2018)
  • Author(s): Soya Hatazaki, Dharmendar Kumar Sharma, Shuzo Hirata, Keiji Nose, Tomokazu Iyoda, Adrian Kolsch, Heiko Lokstein, Martin Vacha
  • Journal Title: The Journal of Physical Chemistry Letters Volume: 9 Pages: 6669-6675
  • Peer Reviewed
• [Journal Article] Narrow band-edge photoluminescence from AgInS2 semiconductor nanoparticles by the formation of amorphous III-VI semiconductor shells (2018)
  • Author(s): Taro Uematsu, Kazutaka Wajima, Dharmendar Kumar Sharma, Shuzo Hirata, Takahisa Yamamoto, Tatsuya Kameyama, Martin Vacha, Tsukasa Torimoto, and Susumu Kuwabata
  • Journal Title: NPG Asia Mater. Volume: 10 Issue: 8 Pages: 713-726
  • DOI: 10.1038/s41427-018-0067-9
  • Peer Reviewed / Open Access
• [Journal Article] Intrinsic Analysis of Radiative and Room-Temperature Nonradiative Processes Based on Triplet State Intramolecular Vibrations of Heavy Atom-Free Conjugated Molecules toward Efficient Persistent Room-Temperature Phosphorescence (2018)
  • Author(s): Shuzo Hirata
  • Journal Title: The Journal of Physical Chemistry Letters Volume: 9 Issue: 15 Pages: 4251-4259
  • DOI: 10.1021/acs.jpclett.8b01711
  • Peer Reviewed
• [Journal Article] Ultralong-Lived Room Temperature Triplet Excitons: Molecular Persistent Room Temperature Phosphorescence and Nonlinear Optical Characteristics with Continuous Irradiation (2018)
  • Author(s): Shuzo Hirata
  • Journal Title: Journal of Materials Chemistry Volume: 6 Issue: 44 Pages: 11785-11794
  • DOI: 10.1039/c8tc01417e
  • Peer Reviewed
• [Journal Article] Large Refractive Index Variations Induced by Accumulating Triplet Excitons under Photoexcitation at Low Power (2018)
  • Author(s): Tomoe Hori, Kenro Totani, Shuzo Hirata, Toshiyuki Watanabe
  • Journal Title: Chemical Physics Letters Volume: 704 Pages: 5-10
  • DOI: 10.1016/j.cplett.2018.05.029
  • Peer Reviewed
• [Presentation] 実験と理論の協働によるπ共役系凝集体における三重項失活メカニズムの考察 第69回高分子討論会 無 平田修造 2020/09/16 21国内会議招待講演 蓄光ナノイメージングを可能にする高輝度残光型室温りん光分子の開発 (2020)
  • Author(s): 平田修造
  • Organizer: 第69回高分子討論会
  • Invited
• [Presentation] 蓄光ナノイメージングを可能にする高輝度残光型室温りん光分子の開発 (2020)
  • Author(s): 平田修造
  • Organizer: 第69回高分子討論会
  • Invited
• [Presentation] Highly Efficient Persistent Room Temperature Phosphorescence From Heavy Atom Free Molecules Triggered By Hidden Long Phosphorescent Antenna (2020)
  • Author(s): Indranil Bhattacharjee, Shuzo Hirata
  • Organizer: Web Annual Meeting on Photochemistry 2020
• [Presentation] ドナーアクセプター直交型キラル分子を利用した高効率熱活性化遅延蛍光発生要因の考察 (2020)
  • Author(s): 林希久也、松本有正、平田修造
  • Organizer: 2020年web光化学討論会
• [Presentation] The effect of the lowest singlet excited state lifetime on up-conversion emission via stepwise two-photon absorption (2020)
  • Author(s): Kentaro Yomogita, Shuzo Hirata
  • Organizer: Web Annual Meeting on Photochemistry 2020
• [Presentation] 置換基誘起の対称禁制遷移分子を用いた弱連続青色光下での大きな光制限効果 (2020)
  • Author(s): 釜付卓弥、Bhattacharjee Indranil、平田修造
  • Organizer: 日本化学会第101回春季年会
• [Presentation] Intrinsic analysis of transition processes from the lowest excited triplet state of heavy atom-free molecules with persistent room-temperature phosphorescence (2020)
  • Author(s): Shuzo Hirata
  • Organizer: SPIE Photonics Europe, Digital Forum
  • Int'l Joint Research / Invited
• [Presentation] Intrinsic analysis of transition processes from the lowest excited triplet state of heavy atom-free conjugated molecular crystals with persistent room temperature phosphorescence (2019)
  • Author(s): Shuzo Hirata
  • Organizer: 2019 MRS Fall Meeting
  • Int'l Joint Research / Invited
• [Presentation] Donor-acceptor molecules showing photon upconversion emission by stepwise two photon absorption (2019)
  • Author(s): YOMOGITA Kentaro, ZHANG Junxiang, MIZUTANI Ryota, VAHCA Martin, KAMADA Kenji, MARDER Seth, HIRATA Shuzo
  • Organizer: Annual Meeting on Photochemistry 2019
• [Presentation] Analysis of Triplet State in Conjugated Molecular Crystals toward Persistent Room Temperature Phosphorescence from Soft Crystals (2019)
  • Author(s): Shuzo Hirata
  • Organizer: The 2nd International Symposium of Soft Crystals
  • Int'l Joint Research / Invited
• [Presentation] Exciton management for unique molecular emission characteristics (2019)
  • Author(s): Shuzo Hirata
  • Organizer: The 36th International Conference of Photopolymer Science and Technology (ICPST-36)
  • Int'l Joint Research / Invited
• [Presentation] Molecular Materials with Ultralong-Lived Room Temperature Triplet Excitons (2019)
  • Author(s): Shuzo Hirata
  • Organizer: 2019 International Seminar on Polymer Photochemistry (2019 ISPP)
  • Int'l Joint Research / Invited
• [Presentation] 分散系および凝集系における重原子フリー分子の三重項励起状態 (2019)
  • Author(s): 平田修造
  • Organizer: 141 M&BE 新分野開拓研究会「有機半導体制御技術の最新動向～分子配向・電荷・励起子～」
  • Invited
• [Presentation] 高効率分子蓄光に向けた三重項からの輻射と非輻射過程の解析 (2019)
  • Author(s): 平田修造
  • Organizer: 日本化学会第99回春季年会 特別企画 ルミネッセンス化学アンサンブル：発光の未来を探る
  • Invited
• [Presentation] 遷移双極子が小さい光学活性分子材料：円偏光遅延蛍光と円偏光室温蓄光 (2019)
  • Author(s): 平田修造
  • Organizer: 千葉大学分子キラリティーセンター定例研究会
  • Invited
• [Presentation] 分散系共役分子および凝集系共役分子結晶の室温長寿命三重項励起子のサイエンスと機能 (2018)
  • Author(s): 平田修造
  • Organizer: 東北大学PHyM若手フォーラム
  • Invited
• [Presentation] Intrinsic analysis of radiative process, intramolecular vibrational room-temperature nonradiative process, and quenching process from triplet state for heavy atom-free conjugated structures (2018)
  • Author(s): Shuzo Hirata
  • Organizer: Annual Meeting on Photochemistry on 2018
  • Invited
• [Presentation] Intrinsic Analysis between Radiative Process and Room-Temperature Nonradiative Process based on Intramolecular Vibrations from Triplet State of Heavy Atom-free Aromatics toward Efficient Persistent Room-temperature Phosphorescence (2018)
  • Author(s): Shuzo Hirata
  • Organizer: 2018 International Seminar on Advanced Materials Research 2018 ISAMR
  • Int'l Joint Research / Invited
• [Book] 化学工業6月号 (2021)
  • Author(s): 平田修造
  • Total Pages: 6
  • Publisher: 株式会社化学工業社
• [Book] Single-Molecule Level Study and Control of Collective Photosynergetic Responses in Molecules and Molecular Aggregates; Photoresponse in Molecular Complexes and Related Systems (2020)
  • Author(s): Martin Vacha, Shuzo Hirata
  • Total Pages: 21
  • Publisher: Springer, Singapore
  • ISBN: 9789811554513
• [Book] コンバーテック12月号：明るい環境下でも視認可能な高輝度蓄光分子 (2020)
  • Author(s): 平田修造
  • Total Pages: 4
  • Publisher: 株式会社加工技術研究会
• [Book] OPTRONICS11月号 (2020)
  • Author(s): 平田修造
  • Total Pages: 6
  • Publisher: 株式会社オプトロニクス社
• [Book] 環状高分子の合成と機能発現 (2018)
  • Author(s): 平田修造、バッハマーティン
  • Total Pages: 9
  • Publisher: シーエムシー出版
  • ISBN: 9784781313993
• [Patent(Industrial Property Rights)] 発光材料、及び蓄光材料 (2020)
  • Inventor(s): 平田修造、バタチャージーインドラニル
  • Industrial Property Rights Holder: 平田修造、バタチャージーインドラニル
  • Industrial Property Rights Type: 特許
  • Filing Date: 2020
• [Patent(Industrial Property Rights)] 発光材料、及び蓄光材料 (2020)
  • Inventor(s): 平田 修造 , バタチャージー インドラニル
  • Industrial Property Rights Holder: 平田 修造 , バタチャージー インドラニル
  • Industrial Property Rights Type: 特許
  • Industrial Property Number: 2020-078341
  • Filing Date: 2020