ITO-free inverted polymer solar cells with ZnO:Al cathodes and stable top anodes

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Antonietta De Sio - , University of Oldenburg (Author)
  • Kambulakwao Chakanga - , NEXT ENERGY (Author)
  • Oleg Sergeev - , NEXT ENERGY (Author)
  • Karsten Von Maydell - , NEXT ENERGY (Author)
  • Jürgen Parisi - , University of Oldenburg (Author)
  • Elizabeth Von Hauff - , University of Freiburg, Fraunhofer Institute for Solar Energy Systems (Author)

Abstract

We report on the application of ZnO:Al as the transparent conductive oxide in high performance inverted polymer solar cells. We show that the optimized inverted architecture, which does not contain low work function metals or water-based transport layers, can be employed without sacrificing device efficiency. The widely studied P3HT:PCBM donoracceptor system was chosen for the active layer. ZnO:Al layers were produced by dc-magnetron sputtering on glass substrates and used as the cathode. The thickness of ZnO:Al was optimized to achieve a low sheet resistance while maintaining high transmission. The resulting ZnO:Al layers were smoother than the reference ITO samples, and the active layers could be processed directly onto ZnO:Al without employing additional buffer layers. The structure of the top anodic contact was also optimized. Initial devices with an Au layer demonstrated poor results, and device performance improved when a MoO 3/Ag anode was used. Control devices in the standard forward structure using commercial ITO coated glass substrates were compared to the ZnO:Al based cells. Higher photocurrents were obtained in the inverted structures than in the ITO-based solar cells due to the higher transmittance of ZnO:Al in the spectral range where the blend absorbs.

Details

Original languageEnglish
Pages (from-to)52-56
Number of pages5
JournalSolar energy materials and solar cells
Volume98
Publication statusPublished - Mar 2012
Peer-reviewedYes
Externally publishedYes

External IDs

ORCID /0000-0002-6269-0540/work/172082579

Keywords

Sustainable Development Goals

Keywords

  • Inverted solar cell, ITO-free, PEDOT:PSS free, Polymer solar cell, ZnO:Al