Positive and negative magnetic field effects in organic semiconducting materials

Liang Yan, Yue Wu, Zhihua Xu, Bin Hu

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

It has been found that non-magnetic organic semiconducting materials can exhibit magnetic responses in electrical current, electroluminescence, photoluminescence, and photocurrent when an external magnetic field is applied. These intrinsic magnetic responses can be naturally attributed to (i) magnetic field-dependent singlet/triplet ratio and (ii) singlet/triplet ratio-dependent excited processes. We observe that inter-molecular and intra-molecular excited states are sensitive and insensitive, respectively, to external magnetic field in magnetic field dependences of electroluminescence, photocurrent, and photoluminescence. This experimental phenomenon suggests that the electron-hole separation distance essentially determines whether magnetic field effects can be activated through the competition between spin-exchange interaction-induced singlet-triplet energy difference and magnetic Zeeman splitting when applied magnetic field is stronger than spin-orbital coupling. Furthermore, the dissociation in inter-molecular excited states and exciton-charge reaction in intra-molecular excited states have positive and negative responses to external magnetic field. As a result, controlling the dissociation in inter-molecular excited states and the exciton-charge reaction in intra-molecular excited states provide an effective methodology to tune the magnetic field effects between positive and negative values in organic semiconducting materials.

Original languageEnglish (US)
Pages (from-to)2323-2325
Number of pages3
JournalSynthetic Metals
Volume159
Issue number21-22
DOIs
StatePublished - Nov 1 2009

Fingerprint

Magnetic field effects
Excited states
Magnetic fields
magnetic fields
Electroluminescence
Photocurrents
Excitons
excitation
Photoluminescence
electroluminescence
photocurrents
Exchange interactions
excitons
dissociation
photoluminescence
spin exchange
Electrons
methodology
orbitals

Keywords

  • Magnetic field effects
  • Organic electroluminescence
  • Organic photovoltaic

Cite this

Positive and negative magnetic field effects in organic semiconducting materials. / Yan, Liang; Wu, Yue; Xu, Zhihua; Hu, Bin.

In: Synthetic Metals, Vol. 159, No. 21-22, 01.11.2009, p. 2323-2325.

Research output: Contribution to journalArticle

Yan, Liang ; Wu, Yue ; Xu, Zhihua ; Hu, Bin. / Positive and negative magnetic field effects in organic semiconducting materials. In: Synthetic Metals. 2009 ; Vol. 159, No. 21-22. pp. 2323-2325.
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