Vibronic coherence contributes to photocurrent generation in organic semiconductor heterojunction diodes

Research output: Contribution to journalArticle

Abstract

Charge separation dynamics after the absorption of a photon is a fundamental process relevant both for photosynthetic reaction centers and artificial solar conversion devices. It has been proposed that quantum coherence plays a role in the formation of charge carriers in organic photovoltaics, but experimental proofs have been lacking. Here we report experimental evidence of coherence in the charge separation process in organic donor/acceptor heterojunctions, in the form of low frequency oscillatory signature in the kinetics of the transient absorption and nonlinear two-dimensional photocurrent spectroscopy. The coherence plays a decisive role in the initial ~200 femtoseconds as we observe distinct experimental signatures of coherent photocurrent generation. This coherent process breaks the energy barrier limitation for charge formation, thus competing with excitation energy transfer. The physics may inspire the design of new photovoltaic materials with high device performance, which explore the quantum effects in the next-generation optoelectronic applications.

Details

Authors
  • Qingzhen Bian
  • Fei Ma
  • Shula Chen
  • Qi Wei
  • Xiaojun Su
  • Irina A. Buyanova
  • Weimin M. Chen
  • Carlito S. Ponseca
  • Mathieu Linares
  • Khadga J. Karki
  • Arkady Yartsev
  • Olle Inganäs
Organisations
External organisations
  • Linköping University
  • KTH Royal Institute of Technology
  • University of Macau
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics
Original languageEnglish
Article number617
JournalNature Communications
Volume11
Publication statusPublished - 2020 Jan 30
Publication categoryResearch
Peer-reviewedYes