Direct evidence of photoinduced electron transfer in conducting-polymer-C60 composites by infrared photoexcitation spectroscopy

Kwanghee Lee, R.A.J. Janssen, N.S. Sariciftci, A.J. Heeger

Research output: Contribution to journalArticleAcademicpeer-review

99 Citations (Scopus)
131 Downloads (Pure)

Abstract

We report direct spectral evidence of photoinduced electron transfer from the excited state of poly(3-octylthiophene), P3OT, onto C60 by infrared photoexcitation spectroscopy, 0.01 eV (100 cm-1) to 1.3 eV (11 000 cm-1). The photoinduced absorption spectrum of P3OT, characterized by subgap electronic absorptions and associated infrared-active vibrational modes, is significantly enhanced in magnitude upon adding a few percent of C60. Two new peaks are found in the photoexcited spectrum of the P3OT/C60 composite and assigned to the allowed HOMO (T1u)-LUMO (T1g) transitions of C60- with energies, 1.15 and 1.25 eV, in good agreement with calculated values. The photoinduced charge transfer from P3OT onto C60 enhances the quantum efficiency for photogeneration of charge carriers resulting in charge separation in the excited state. As a result, the lifetime of the excited-state configuration, (P3OT)+ and C60-, is extended; thereby leading to both the enhanced photoinduced response of P3OT and the appearance of the 1.15- and 1.25-eV signatures associated with C60-.
Original languageEnglish
Pages (from-to)5781-5784
Number of pages4
JournalPhysical Review B: Condensed Matter
Volume49
Issue number8
DOIs
Publication statusPublished - 1994

Fingerprint

Dive into the research topics of 'Direct evidence of photoinduced electron transfer in conducting-polymer-C60 composites by infrared photoexcitation spectroscopy'. Together they form a unique fingerprint.

Cite this