Organic tandem solar cells: How impedance analyses can improve the quality of external quantum efficiency measurements

Daniel Bahro, Manfred Wilck, Adrian Mertens, Bernd Ebenhoch, Elizabeth von Hauff, Alexander Colsmann*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

116 Downloads (Pure)

Abstract

Tandem architectures are one of the most promising concepts towards
superior power conversion efficiencies of organic solar cells. An accurate determination of the power conversion efficiency requires correction of the spectral mismatch and thus relies on accurate external quantum efficiency (EQE) spectra. Due to the series connection of 2 subcells in the tandem architecture, the EQE of the tandem solar cell reproduces the EQE of one subcell if an appropriate bias light is chosen to selectively illuminate and hence forward bias the other subcell. The resulting internal voltage drop is then compensated by applying an external voltage to the tandem solar cell. In this work, we use impedance spectroscopy to accurately predict the minimum bias light intensity and the external voltage to enable accurate EQE measurements on both subcells. We exemplify this procedure on organic tandem solar cells comprising spectrally complementary absorbers and suggest an extended protocol for future measurements of the EQE.
Original languageEnglish
Pages (from-to)763-777
Number of pages15
JournalProgress in Photovoltaics: Research and Applications
Volume26
Issue number10
Early online date28 May 2018
DOIs
Publication statusPublished - Oct 2018

Keywords

  • bias illumination
  • bias voltage
  • EQE
  • impedance spectroscopy
  • organic photovoltaics
  • tandem solar cell

Fingerprint

Dive into the research topics of 'Organic tandem solar cells: How impedance analyses can improve the quality of external quantum efficiency measurements'. Together they form a unique fingerprint.

Cite this