Ligand-free preparation of polymer/CuInS2 nanocrystal films and the influence of 1,3-benzenedithiol on their photovoltaic performance and charge recombination properties

Thomas Rath, Dorothea Scheunemann, Roberto Canteri, Heinz Amenitsch, Jasmin Handl, Karin Wewerka, Gerald Kothleitner, Simon Leimgruber, Astrid-Caroline Knall, Saif A. Haque

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Bulk heterojunction solar cells based on conjugated polymer donors and fullerene-derivative acceptors have received much attention in the last decade. Alternative acceptors like organic non-fullerene acceptors or inorganic nanocrystals have been investigated to a lesser extent; however, they also show great potential. In this study, one focus is set on the investigation of the in situ growth of copper indium sulfide nanocrystals in a conjugated polymer matrix. This preparation method allows the fabrication of a hybrid active layer without long-chain ligands, which could hinder charge separation and transport. In contrast, surfactants for the passivation of the nanocrystal surface are missing. To tackle this problem, we modified the absorber layer with 1,3-benzenedithiol and investigated the influence on charge transfer and solar cell performance. Using ToF-SIMS measurements, we could show that 1,3-benzenedithiol is successfully incorporated and homogeneously distributed in the absorber layer, which significantly increases the power conversion efficiency of the corresponding solar cells. This can be correlated to an improved charge transfer between the nanocrystals and the conjugated polymer as revealed by transient absorption spectroscopy as well as prolonged carrier lifetimes as disclosed by transient photovoltage measurements.

Original languageEnglish
Pages (from-to)943-952
Number of pages952
JournalJournal of Materials Chemistry C
Volume7
Issue number4
DOIs
Publication statusPublished - 2019

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ASJC Scopus subject areas

  • Materials Chemistry
  • Chemistry(all)

Fields of Expertise

  • Advanced Materials Science

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