Spontaneous Orientation of Alq3 Molecule in Evaporated Film and Its Vanishment by Light Irradiation

Keiji Sugi, Hisao Ishii, Yasuo Kimura, Michio Niwano, Naoki Hayashi, Yukio Ouchi, Eisuke Ito, Kazuhiko Seki

Research output: Contribution to journalConference articlepeer-review


Recently we found high and persistent spontaneous buildup of the surface potential upon vacuum vapor deposition of tris(8-hydroxyquinolinato) aluminum(III)(Alq3) on Au substrate under dark conditions (28 V for 560 nm thick Alq3 film). Such giant potential is removed by visible-light irradiation. These natures of the film suggest the possible applications to various organic devices such as memory devices. In this study, we investigated the retention time of the giant potential and the mechanism of the light-induced depolarization in order to discuss the feasibility of the device applications. The observed decay rate of the surface potential in vacuum condition was roughly 10 % loss in 10 years, which is enough for memory devices. As to the decay rate by light-irradiation, the observed rate was successfully reproduced by a theoretical simulation based on the photo-induced randomization of oriented Alq3 molecules.

Original languageEnglish
Pages (from-to)213-218
Number of pages6
JournalMaterials Research Society Symposium - Proceedings
Publication statusPublished - 2003
EventOrganic and Polymeric Materials and Devices - San Francisco, CA, United States
Duration: 2003 Apr 222003 Apr 25

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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