Elucidation of Electronic Properties of Organic Semiconductors by Direct Observation of Frontier Density of States

2012 Fiscal Year Final Research Report

• Project/Area Number: 21245042
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Functional materials/Devices
• Research Institution: Chiba University
• Principal Investigator: ISHII Hisao 千葉大学, 先進科学センター, 教授 (60232237)
• Co-Investigator(Kenkyū-buntansha): NOGUCHI Yutaka 千葉大学, 先進科学センター, 助教 (20399538) ; NAKAYAMA Yasuo 千葉大学, 先進科学センター, 特任講師 (30451751) ; MIYAMAE Takayuki 産業技術総合研究所, ナノシステム研究部 門, 研究員 (80358134)
• Project Period (FY): 2009 – 2012
• Keywords: 有機半導体 / 紫外光電子分光 / 光電子収量分光 / ギャップ準位 / 界面電子構造 / 接触帯電 / 絶縁性高分子 / 界面電荷 / 巨大表面電位 / 埋もれた界面

Research Abstract

In order to understand the mechanism of electronic devices using organic molecules, it is indispensable to elucidate how electrons are stored in molecules. So far, it has been investigated focusing on electronic states such as HOMO and LUMO. But other electronic states called gap s t at e s , whose density is less than one thousandth of HOMO, is also important for device physics. In this study, we have developed an apparatus to directly measure such gap states, and investigated the electronic structures of various organic semiconductors.

Research Products

• [Journal Article] Influence of the direction of spontaneous orientation polarization on the charge injection properties of organic light-emitting diodes (2013)
  • Author(s): Yutaka Noguchi, Hyunsoo Lim, Takashi Isoshima, Eisuke Ito, Masahiko Hara, Whee Won Chin, Jin Wook Han, Hiroumi Kinjo, Yusuke Ozawa, Yasuo Nakayama, and Hisao Ishii
  • Journal Title: Applied Physics Letters Volume: 102(20) Pages: 203306-1-5
• [Journal Article] Low-Energy Photoemission Study of C60/Rubrene/Au Interfaces in Practical Device Thickness (2013)
  • Author(s): Shin'ichi Machida, Yusuke Ozawa, Juni-ichi Takahashi, Hiroshi Tokairin, Yasuo Nakayama, Hisao Ishii
  • Journal Title: Applied Physics Express Volume: 6(2) Pages: 025801-1-3
• [Journal Article] Highest occupied molecular orbital banddispersionofrubrenesinglecrystals as observed by angle-resolved ultraviolet photoelectron spectroscopy (2010)
  • Author(s): Shin-ichi Machida, Yasuo Nakayama, Steffen Duhm, Qian Xin, Akihiro Funakoshi, Naoki Ogawa, Satoshi Kera, Nobuo Ueno, Hisao Ishii
  • Journal Title: Physical Review Letters Volume: 104(15) Pages: 156401-1-4
• [Presentation] In situ measurement of displacement current measurement and ultraviolet photoelectron spectroscopy to examine carrier injection property of organic-electrode interface (2012)
  • Author(s): Hisao Ishii, Taiki Yamada, Yusuke Ozawa, Shin-ichi Machida, Yukio Ouchi, Yasuo Nakayama, Yutaka Noguchi
  • Organizer: 2012 SPIE Optics+Photonics
  • Place of Presentation: San Diego
  • Year and Date: 20120812-16
• [Presentation] Intrinsic and extrinsic electronic structures of organic semiconductors studied by photoemission and photoelectron yield spectroscopy (2012)
  • Author(s): Hisao Ishii
  • Organizer: Gordon Research Conferece (Electronic Processes in Organic Materials Exploring the Fundamentals of Organic Electronics)
  • Place of Presentation: Renaissance Tuscany Il Ciocco Resort Lucca (Barga), Italy
  • Year and Date: 20120603-08
• [Presentation] Electronic investigation inside crystalline organic semiconductors: two-dimensional valence band structures, gap states, and buried interfaces (2012)
  • Author(s): Yasuo Nakayama, Shin'ichi Machida, Jens Niederhausen, Yuki Uragami, Hiroumi Kinjo, K. Rasika Koswattage, Kazuhiko Mase, Antje Vollmer, Juegen P. Rabe, Norbert Koch, Hisao Ishii
  • Organizer: International Symposium on Organic Transistors and Functional Interfaces (OFET2012)
  • Place of Presentation: Princeton, USA
  • Year and Date: 2012-10-28
• [Book] 有機半導体のデバイス物性"(安達千波矢編)第3章「有機/金属界面のエネルギー構造」 (2012)
  • Author(s): 石井久夫
  • Publisher: 講談社