Correlated In Situ Low-Frequency Noise and Impedance Spectroscopy Reveal Recombination Dynamics in Organic Solar Cells Using Fullerene and Non-Fullerene Acceptors

Kyle A. Luck, Vinod K. Sangwan, Patrick E. Hartnett, Heather N. Arnold, Michael R. Wasielewski, Tobin J. Marks, Mark C. Hersam

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Non-fullerene acceptors based on perylenediimides (PDIs) have garnered significant interest as an alternative to fullerene acceptors in organic photovoltaics (OPVs), but their charge transport phenomena are not well understood, especially in bulk heterojunctions (BHJs). Here, charge transport and current fluctuations are investigated by performing correlated low-frequency noise and impedance spectroscopy measurements on two BHJ OPV systems, one employing a fullerene acceptor and the other employing a dimeric PDI acceptor. In the dark, these measurements reveal that PDI-based OPVs have a greater degree of recombination in comparison to fullerene-based OPVs. Furthermore, for the first time in organic solar cells, 1/f noise data are fit to the Kleinpenning model to reveal underlying current fluctuations in different transport regimes. Under illumination, 1/f noise increases by approximately four orders of magnitude for the fullerene-based OPVs and three orders of magnitude for the PDI-based OPVs. An inverse correlation is also observed between noise spectral density and power conversion efficiency. Overall, these results show that low-frequency noise spectroscopy is an effective in situ diagnostic tool to assess charge transport in emerging photovoltaic materials, thereby providing quantitative guidance for the design of next-generation solar cell materials and technologies.

Original languageEnglish
Article number1703805
JournalAdvanced Functional Materials
Volume27
Issue number48
DOIs
Publication statusPublished - Dec 22 2017

Keywords

  • 1/f noise
  • PBDTTT-EFT
  • PCBM
  • alternate acceptors
  • organic photovoltaics

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Correlated In Situ Low-Frequency Noise and Impedance Spectroscopy Reveal Recombination Dynamics in Organic Solar Cells Using Fullerene and Non-Fullerene Acceptors'. Together they form a unique fingerprint.

  • Cite this