有機半導体電極界面のキャリア注入・取り出し機構の解明

2015 Fiscal Year Annual Research Report

• Project/Area Number: 25288114
• Research Institution: Chiba University
• Principal Investigator: 石井 久夫 千葉大学, 先進科学センター, 教授 (60232237)
• Co-Investigator(Kenkyū-buntansha): 野口 裕 明治大学, 理工学部, 准教授 (20399538) ; 中山 泰生 東京理科大学, 理工学部, 講師 (30451751) ; K.K. Rasika 千葉大学, 先進科学センター, 特任助教 (90631557)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 高感度光電子分光 / 有機半導体 / 負イオン光電子分光 / 状態密度 / ギャップ準位 / 光電子収量分光 / 電子親和力

Outline of Annual Research Achievements

本研究では、有機半導体デバイスの性能を左右するキャリアの注入・取り出し機構に関して、“障壁高さ（バリアハイト）”という一元的なパラメーターで解釈してきた従来モデルを脱却するために、ギャップ準位などの微弱準位も含めた状態密度を光電子分光により直接観測し、電気特性との比較により、キャリア注入現象の本質を解明することを目指した。最終年度におていは、以下のような成果を得た。
１）励起光の波長を細かく掃引しながら多数の光電子スペクトルを測定し、電子エネルギー分析器のゴーストシグナルの影響をうけることなくギャップ内準位を高感度に測定することに成功した。得られたスペクトルを接続することによって、光イオン化断面積の違いを補正した状態密度(DOS)を測定できた。当初計画（４桁）を大きく上回る７桁の測定レンジを達成した。２）蒸着するだけで配向分極を示す有機EL材料群に対して、高感度光電子分光を行うと、表面に存在する分極電荷によって捕捉された負イオンの電子構造を直接観測できることを示し、LUMO準位の直接観測に成功した。３）正孔輸送材料としてしられるαーNPDについて高感度光電子分光によりDOSを求めた。さらに、得られたDOSと実測の電気伝導に基づいて移動度端を推定する手法を提案した。４）倒立型の有機EL素子においては、底部の透明電極からの電子注入を改善するためにポリエチレンイミン(PEI)層を挿入することがしばしば行われている。ITO/PEI/Bebq2モデル界面の測定をおこない、エネルギー準位の接続を明らかにするとともに、Bebq2の負イオン状態が生じていることを見出した。５）超高真空内でのin-situ電気測定に関しては、トランジスタ構造を用いたキャリア状態の直接観測の実験を優先的に進め、収量分光により動作中のトランジスタ構造中の負イオンからの光電子放出と思われるシグナルを観測した。

Research Progress Status

27年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

27年度が最終年度であるため、記入しない。

Causes of Carryover

27年度が最終年度であるため、記入しない。

Expenditure Plan for Carryover Budget

27年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] アウグスブルグ大学(ドイツ)
  • Country Name: GERMANY
  • Counterpart Institution: アウグスブルグ大学
• [Int'l Joint Research] 國立清華大学(台湾)
  • Country Name: その他の国・地域
  • Counterpart Institution: 國立清華大学
• [Journal Article] Significant relaxation of residual negative carrier in polar Alq3 film directly detected by high-sensitivity photoemission (2016)
  • Author(s): Hiroumi Kinjo, Hyunsoo Lim, Tomoya Sato, Yutaka Noguchi, Yasuo Nakayama and Hisao Ishii
  • Journal Title: Applied physics letters Volume: 9 Pages: 021601-1~4
  • DOI: http://doi.org/10.7567/APEX.9.021601
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Electronic Structures of a Well-Defined Organic Hetero-Interface: C60 on Pentacene Single Crystal (2015)
  • Author(s): Masayuki Yamamoto, Yasuo Nakayama, Yuki Uragami, Hiroumi Kinjo, Yuta Mizuno, Kazuhiko Mase, Kaveenga Rasika Koswattage, Hisao Ishii
  • Journal Title: e-Journal of Surface Science and Nanotechnology Volume: 13 Pages: 59-64
  • DOI: http://doi.org/10.1380/ejssnt.2015.59
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Effects of Interface Electronic Structures on Transition Voltage Spectroscopy of Alkanethiol Molecular Junctions (2015)
  • Author(s): Daisuke Nose, Kouki Dote, Tomoya Sato, Makoto Yamamoto, Hisao Ishii, Yutaka Noguchi
  • Journal Title: The Journal of Physical Chemistry C Volume: 119 Pages: 12765-12771
  • DOI: 10.1021/acs.jpcc.5b03296
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Charge carrier dynamics and degradation phenomena in organic light-emitting diodes doped by a thermally activated delayed fluorescence emitter (2015)
  • Author(s): Yutaka Noguchi, Hyung-Jun Kim, Ryuta Ishino, Kenichi Goushi, Chihaya Adachi, Yasuo Nakayama, Hisao Ishii
  • Journal Title: Organic Electronics Volume: 17 Pages: 184-191
  • DOI: doi:10.1016/j.orgel.2014.12.009
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Electronic Structure of Chlorophyll a Solution Investigated by Photoelectron Yield Spectroscopy (2015)
  • Author(s): Yuki Takeda, Hiroshi Ezawa, Takuya Miyauchi, Hiroumi Kinjo, Kaveenga Rasika Koswattage, Yasuo Nakayama, Hisao Ishii
  • Journal Title: Applied Mechanics and Materials Volume: 763 Pages: 58-60
  • Peer Reviewed
• [Journal Article] Analyzing Degradation Effects of Organic Light-Emitting Diodes via Transient Optical and Electrical Measurements (2015)
  • Author(s): Tobias D. Schmidt, Lars Jaeger, Yutaka Noguchi, Hisao Ishii, and Wolfgang Bruetting
  • Journal Title: Journal of Applied Physics Volume: 117 Pages: 215502-1~10
  • Peer Reviewed / Int'l Joint Research
• [Presentation] 高感度光電子分光によるITO/PEI/Bebq2界面の電子構造の観測 (2016)
  • Author(s): 清水 康平, 深川 弘彦, 森井 克行, 金城 拓海, 佐藤 友哉, 石井 久夫
  • Organizer: 第63回応用物理学会春季学術講演会
  • Place of Presentation: 東京工業大学
  • Year and Date: 2016-03-19 – 2016-03-22
• [Presentation] 波長掃引型紫外光電子分光による状態密度のワイドレンジ計測:サブppmレベルの超高感度検出 (2016)
  • Author(s): 佐藤 友哉，金城 拓海，山﨑 純暉，石井 久夫
  • Organizer: 第63回応用物理学会春季学術講演会
  • Place of Presentation: 東京工業大学
  • Year and Date: 2016-03-19 – 2016-03-22
• [Presentation] 有機半導体のバルク・界面電子構造評価の最前線 Trends in Evaluation of Bulk and Interface Electronic Structures of Organic Semiconductors (2016)
  • Author(s): Hisao Ishii
  • Organizer: Japan-Korea Joint Symposium on Organic Electronics 日韓の有機エレクトロニクス研究:現状と次の飛躍に向けて, 応用物理学会 2016年第63回応用物理学会春季学術講演会
  • Place of Presentation: 東京工業大学
  • Year and Date: 2016-03-19
  • Invited
• [Presentation] 「ペロブスカイト太陽電池」モデル界面の電子構造とその水蒸気曝露による変化 (2016)
  • Author(s): 中山 泰生，早川 慧，佐藤 友哉，鶴田 諒平，土手 宏樹，石井 久夫,間瀬 一彦，Ludmila Cojocaru，内田 聡
  • Organizer: 2015年度量子ビームサイエンスフェスタ
  • Place of Presentation: つくば国際会議場
  • Year and Date: 2016-03-15 – 2016-03-16
• [Presentation] High Sensitivity Photoemission and Photoelectron Yield Spectroscopy from Polar OLED Films: Existence of Shallow States above Fermi Level (2016)
  • Author(s): Hiroumi Kinjo, Tomoya Sato, Hyunsoo Lim, Hyung-Jun Kim, Junki Yamazaki, Koki Dote, Yutaka Noguchi, Yasuo Nakayama, Hisao Ishii
  • Organizer: 2016 Discussion Meeting on Organic-Inorganic Hybrids Electronics: Charge Transport, Structure and Electronic States
  • Place of Presentation: Chiba
  • Year and Date: 2016-03-02
  • Int'l Joint Research
• [Presentation] Photoemission in atmospheric environment: from organic semiconductor to biomolecule (2016)
  • Author(s): H. Ishii, Y. Takeda, T. Yamashita, T. Miyauchi, H. Ezawa, H. Kinjo, T. Sato, K. R. Koswattage, and Y. Nakayama
  • Organizer: The First Symposium of Chiral Molecular Science and Technology in Chiba University -Advanced Materials Science, Biology & Nanophotonics in Chiba
  • Place of Presentation: Chiba
  • Year and Date: 2016-02-29 – 2016-03-01
  • Int'l Joint Research
• [Presentation] Negative Ion Photoemission Spectroscopy from Polar Organic LED Films (2015)
  • Author(s): H. Kinjo, T. Sato, Y. Nakayama, and H. Ishii
  • Organizer: Anjou University - Chiba University Symposium 2015
  • Place of Presentation: Suwon, Korea
  • Year and Date: 2015-12-12
  • Int'l Joint Research / Invited
• [Presentation] High-Sensitivity UV Photoemission of α-NPD Film Doped with HAT-CN (2015)
  • Author(s): Junki Yamazaki，Hiroumi Kinjo, Tomoya Sato, Yuki Takeda, Yasuo Nakayama, Hisao Ishii
  • Organizer: Ajou University - Chiba University Symposium
  • Place of Presentation: Suwon, Korea
  • Year and Date: 2015-12-11 – 2015-12-12
  • Int'l Joint Research
• [Presentation] High Sensitivity Photoemission Spectroscopy and Photoelectron Yield Spectroscopy of Polarized OLED Thin Films (2015)
  • Author(s): H. Kinjo, T. Sato, J. Yamasaki, K. Dote, Y. Noguchi, Y. Nakayama, and H. Ishii
  • Organizer: The 3rd Workshop on Physics in Organic Optoelectronics
  • Place of Presentation: Okazaki, Japan
  • Year and Date: 2015-12-10 – 2015-12-11
  • Int'l Joint Research / Invited
• [Presentation] Direct Observation of Weak Density of States of Polymers by High Sensitivity Photoemission (2015)
  • Author(s): omoya Sato, Kaveenga Rasika Koswattage, Yasuo Nakayama, Hisao Ishii
  • Organizer: The 3rd Workshop on Physics in Organic Optoelectronics
  • Place of Presentation: Okazaki, Japan
  • Year and Date: 2015-12-10 – 2015-12-11
  • Int'l Joint Research
• [Presentation] High Sensitivity Photoemission Spectroscopy of ITO/PEI/Bebq2 Interfaces (2015)
  • Author(s): Kohei Shimizu, Hiroumi Kinjo, Tomoya Sato, Junki Yamazaki, Hisao Ishii
  • Organizer: The 3rd Workshop on Physics in Organic Optoelectronics
  • Place of Presentation: Okazaki, Japan
  • Year and Date: 2015-12-10 – 2015-12-11
  • Int'l Joint Research
• [Presentation] Negative Ion Photoemission Spectroscopy from Thin Films Related to Organic Light Emitting Diodes 有機EL材料薄膜の負イオン光電子分光 (2015)
  • Author(s): Hirofumi Kinjo, Tomoya Sato, Yasuo Nakayama, Hisao Ishii
  • Organizer: 表面界面スペクトロスコピー2015
  • Place of Presentation: 埼玉
  • Year and Date: 2015-11-27 – 2015-11-28
• [Presentation] Direct Observation of Density of States of Polymers by High Sensitivity Ultraviolet Photoemission Spectroscopy (2015)
  • Author(s): Tomoya Sato, Kaveenga Rasika Koswattage, Yasuo Nakayama, Hisao Ishii
  • Organizer: 表面・界面スペクトロスコピー2015
  • Place of Presentation: 埼玉
  • Year and Date: 2015-11-27 – 2015-11-28
• [Presentation] Energetic Relaxation of Anions in OLED Films Directly Observed by High Sensitivity Photoemission: Impact of Orientation Polarization on Electron Injection (2015)
  • Author(s): Hiroumi Kinjo, Tomoya Sato, Hyunsoo Lim, Hyung-Jun Kim, Junki Yamazaki, Koki Dote, Yutaka Noguchi, Yasuo Nakayama, Hisao Ishii
  • Organizer: 2015 Solid-State and Organic Lighting (SOLED)
  • Place of Presentation: 蘇州、中国
  • Year and Date: 2015-11-02 – 2015-11-05
  • Int'l Joint Research / Invited
• [Presentation] 有機EL材料における極性配向と光誘起負イオンドーピングの実測 (2015)
  • Author(s): 金城 拓海，Lim Hyunsoo，佐藤 友哉，大澤 祐介，山﨑 純暉，中光 栄仁，野口 裕，中山 泰生，石井 久夫
  • Organizer: 第5回CSJ化学フェスタ2015
  • Place of Presentation: 東京
  • Year and Date: 2015-10-15
• [Presentation] Direct Observation of Weak Density of States of Organic Films by High Sensitivity Photoemission and Photoelectron Yield Spectroscopy (2015)
  • Author(s): Tomoya Sato, Hiroumi Kinjo, Koki Dote, Junki Yamazaki, K. Rasika Koswattage, Yasuo Nakayama and Hisao Ishii
  • Organizer: Electronic Structure and Processes at Molecular-Based Interfaces (ESPMI VIII)
  • Place of Presentation: Tucson, USA
  • Year and Date: 2015-10-14 – 2015-10-16
  • Int'l Joint Research
• [Presentation] 負イオン光電子分光で見た極性分子膜における負イオンの蓄積 (2015)
  • Author(s): 金城 拓海，Lim Hyunsoo，大澤 祐介，佐藤 友哉，中光 栄仁，Thanh Luan Nguyen，浦上 裕希，山﨑 純暉，野口 裕，中山 泰生，石井 久夫
  • Organizer: 第76回応用物理学会秋季学術講演会
  • Place of Presentation: 名古屋国際会議場
  • Year and Date: 2015-09-15
  • Invited
• [Presentation] Direct Observation of Surface Anions Relaxed by Spontaneous Orientation Polarization in OLED Films by High Sensitivity Photoemission (2015)
  • Author(s): Hiroumi Kinjo, Tomoya Sato, Hirounjo, Junki Yamazaki, Yutaka Noguchi, Yasuo Nakayama, Hisao Ishii
  • Organizer: SPIE Organic Photonics + Electronics
  • Place of Presentation: San Diego, USA
  • Year and Date: 2015-08-09 – 2015-08-13
  • Int'l Joint Research / Invited
• [Presentation] 光電子放出を用いた仕事関数・電子構造測定 (2015)
  • Author(s): 石井 久夫
  • Organizer: 学振166委員会「第68回研究会」
  • Place of Presentation: 東京
  • Year and Date: 2015-07-17
  • Invited
• [Presentation] The Roles of Interface Charge in Organic Light-Emitting Diodes Doped by a Thermally Activated Delayed Fluorescence Emitter" (2015)
  • Author(s): Yutaka Noguchi,Hyung Jun Kim, Ryuta Ishino, Kenichi Goushi, Chihaya Adachi, Yasuo Nakayama, and Hisao Ishii
  • Organizer: Eighth International Conference on Molecular Electronics and Bioelectronics (M&BE8)
  • Place of Presentation: Tokyo
  • Year and Date: 2015-06-22 – 2015-06-24
  • Int'l Joint Research
• [Presentation] Negative Ion Photoemission (2015)
  • Author(s): Kinjo Hiroumi，Hyunsoo Lim, Yusuke Ozawa, Tomoya Sato, Shigehito Nakamitsu, Thanh Luan Nguyen, Yuki Uragami, Jyunki Yamazaki, Yasuo Nakayama, Hisao Ishii
  • Organizer: Eight International Conference on Molecular Electronics and Bioelectronics
  • Place of Presentation: Tokyo
  • Year and Date: 2015-06-22 – 2015-06-24
  • Int'l Joint Research
• [Presentation] Direct Determination of Density of States of Several Polymers Including Gap States Studied by High Sensitivity Photoemission and Photoelectron Yield Spectroscopy (2015)
  • Author(s): Tomoya Sato，Kaveenga Rasika Koswattage, Yasuo Nakayama, Hisao Ishii
  • Organizer: Eight International Conference on Molecular Electronics and Bioelectronics
  • Place of Presentation: Tokyo
  • Year and Date: 2015-06-22 – 2015-06-24
  • Int'l Joint Research
• [Presentation] Orientation Polarization in Doped OLED : The Formation of Interface Charge and Deep Trap (2015)
  • Author(s): Ryuta Ishino，Shigehito Nakamitsu, Hyung Jun Kim, Yutaka Noguchi, Hisao Ishii
  • Organizer: Eight International Conference on Molecular Electronics and Bioelectronics
  • Place of Presentation: Tokyo
  • Year and Date: 2015-06-22 – 2015-06-24
  • Int'l Joint Research
• [Presentation] Electronic structure of Chlorophyll-a solution observed by Photoelectronic Yield Spectroscopy (2015)
  • Author(s): Yuki Takeda，Hiroshi Ezawa, Takuya Miyauchi, Hiroumi Kinjo, Kaveenga Rasika Koswattage, Yasuo Nakayama, Hisao Ishii
  • Organizer: Eight International Conference on Molecular Electronics and Bioelectronics
  • Place of Presentation: Tokyo
  • Year and Date: 2015-06-22 – 2015-06-24
  • Int'l Joint Research
• [Presentation] 有機EL材料薄膜の負イオン光電子放出の検証 (2015)
  • Author(s): 金城 拓海，Lim Hyunsoo，大澤 祐介，佐藤 友哉，中光 栄仁，Thanh Luan Nguyen，浦上 裕希，山﨑 純暉，中山 泰生，石井 久夫
  • Organizer: 有機EL討論会第20回例会
  • Place of Presentation: 千葉
  • Year and Date: 2015-06-19
• [Presentation] 微量のアクセプタをドープしたα-NPD膜の高感度光電子分光 (2015)
  • Author(s): 山﨑 純暉，金城 拓海，佐藤 友哉，武田 祐希，中山 泰生，石井 久夫
  • Organizer: 有機EL討論会第20回例会
  • Place of Presentation: 千葉
  • Year and Date: 2015-06-19
• [Presentation] High Sensitivity Photoemission and Photoelectron Yield Spectroscopy of Weak Density of States of Organic Functional Films:Direct Detection of Gap States and Anion States (2015)
  • Author(s): Tomoya Sato, Hiroumi Kinjo, K. Rasika Koswattage, Yasuo Nakayama, Hisao Ishii
  • Organizer: The 5th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2015)
  • Place of Presentation: Niigata, Japan
  • Year and Date: 2015-06-16 – 2015-06-19
  • Int'l Joint Research / Invited
• [Presentation] Beyond the Limit of Conventional Photoemission Spectroscopy for Organic Materials (2015)
  • Author(s): Hisao Ishii
  • Organizer: 2015 Japan-Taiwan International Workshop on Spectroscopy and Surface Science
  • Place of Presentation: Chiba, Japan
  • Year and Date: 2015-06-01 – 2015-06-02
  • Int'l Joint Research
• [Presentation] High Sensitivity Photoemission Study of Organic Molecules and Polymers: Direct Detection of Trap States and Charged States (2015)
  • Author(s): Tomoya Sato, Hiroumi Kinjo, K. Rasika Koswattage, Yasuo Nakayama,Hisao Ishii
  • Organizer: Internatioanl conference on moelcular electronics and devices
  • Place of Presentation: Seoul, Korea
  • Year and Date: 2015-05-21 – 2015-05-22
  • Int'l Joint Research / Invited
• [Presentation] Relaxed Anion-State in OLED Films Studied (2015)
  • Author(s): Hiroumi Kinjo, Tomoya Sato, Junki Yamazaki, Yutaka Noguchi, Yasuo Nakayama, Hisao Ishii
  • Organizer: Korean Physics Society Meeting 2015
  • Place of Presentation: Daejon, Korea
  • Year and Date: 2015-04-23
  • Int'l Joint Research / Invited
• [Book] Electronic processes in organic electronics: Bridging nanostructure, electronic states and device propertiesの第８章 (2015)
  • Author(s): Hisao Ishii, Hiroumi Kinjo, Tomoya Sato, Shin-ichi Machida, Yasuo Nakayama
  • Total Pages: 25
  • Publisher: Springer
• [Remarks] 石井研究室WEB
  • URL: http://ishii-lab.in.coocan.jp/pukiwiki/?FrontPage