Effect of temperature on the morphological and photovoltaic stability of bulk heterojunction polymer: fullerene solar cells

Sabine Bertho*, Griet Janssen, Thomas J. Cleij, Bert Conings, Wouter Moons, Abay Gadisa, Jan D'Haen, Etienne Goovaerts, Laurence Lutsen, Jean V. Manca, Dirk Vanderzande

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

In high performance polymer:fullerene bulk heterojunction solar cells the nanoscale morphology of interpenetrating acceptor:donor materials is optimized through appropriate preparation conditions such as annealing and choice of solvent, but this initial state-of-the-art morphology will not remain stable during long-term operation. We report the effects of prolonged storage at elevated temperatures on both the morphology and the photovoltaic performance for the model systems mdmo-ppv:pcbm and p3ht:pcbm as compared to ‘high tg ppv’:pcbm based solar cells, where the ‘high tg ppv’ is characterized by its high glass transition temperature (138 °c). In situ monitoring of the photocurrent–voltage characteristics at elevated temperatures, in combination with a systematic transmission electron microscopy (tem) study and complementary optical spectroscopy, reveals distinct degradation kinetics and morphological changes that indicate the occurrence of different underlying physico-chemical mechanisms.
Original languageEnglish
Pages (from-to)753-760
JournalSolar Energy Materials and Solar Cells
Volume92
Issue number7
DOIs
Publication statusPublished - Jul 2008
Externally publishedYes

Keywords

  • organic photovoltaics
  • thermal stability
  • glass transition temperature
  • morphology

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