Retrieval of electronic spectra of charge carriers in organic field-effect transistors from charge modulation reflectance spectra distorted by optical interference

Kiyoshi Miyata, Yuta Ishino, Kazuya Watanabe, Kazumoto Miwa, Takafumi Uemura, Jun Takeya, Yoshiyasu Matsumoto

Research output: Contribution to journalArticle


Charge modulation (CM) spectroscopy is useful for detecting and characterizing the electronic structure of charge carriers accumulated in organic field-effect transistors (OFETs). However, CM spectra are distorted by optical interference due to multiple reflections in OFETs particularly when reflection configurations are used. In this study, we demonstrated a method for retrieving the spectra of complex refractive indices of carriers from the distorted CM spectra by using a 4 × 4 matrix algorithm with general transition matrices. We tested this method by applying it to the CM spectra of a rubrene single-crystal FET measured at several incident angles of light. In spite of the strong distortion of the CM spectra, we could retrieve the spectrum of the imaginary part of refractive indices, which is similar to that observed in the transmission configuration. This method extends the applicability of CM spectroscopy to OFETs with opaque electrodes, where transmission configurations cannot possibly be applied.

Original languageEnglish
Article number062401
JournalJapanese journal of applied physics
Issue number6 PART 1
Publication statusPublished - Jun 1 2013
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Engineering(all)
  • Physics and Astronomy(all)

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