The direct measurement of energy barrier height at metal/ polyfluorene derivatives interface by internal photoemission spectroscopy

Eiji Itoh, Shinya Takaishi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We have investigated the barrier height for electron injection at the cathode / polyfluorene derivatives interface by the internal photoemission (IPE) spectroscopy techniques using the "electron only device" structure consisting of TiO 2, electron transporting polyimide inter-layer (IL), and polyfluorene derivatives. We also estimated the barrier height by the current analysis based on the Schottky thermal emission current model, and it coincides well to the threshold energy of IPE result only when the energy is lower than 1.1eV. The measured barrier height obtained by IPE linearly increases with both the work-function of cathode materials. However, the slope parameter becomes less than 1 (∼0.6) for poly (9,9-dioctylfluorene) (F8) probably due to the interfacial gap states. On the other hand, the slope parameter becomes very small (∼0.18) for the poly (9,9-dioctylfluorene)-co- benzo- thiadiazole) (F8BT) probably due to the electron pinning at the cathode/ acceptor interface.

Original languageEnglish
Title of host publicationMolecular and Hybrid Materials for Electronics and Photonics
Pages72-77
Number of pages6
DOIs
Publication statusPublished - 2011 Dec 1
Externally publishedYes
Event2010 MRS Fall Meeting - Boston, MA, United States
Duration: 2010 Nov 292010 Dec 3

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1286
ISSN (Print)0272-9172

Other

Other2010 MRS Fall Meeting
CountryUnited States
CityBoston, MA
Period10/11/2910/12/3

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'The direct measurement of energy barrier height at metal/ polyfluorene derivatives interface by internal photoemission spectroscopy'. Together they form a unique fingerprint.

Cite this