Improved stability of non-ITO stacked electrodes for large area flexible organic solar cells

Mike Hambsch, Hui Jin, Andrew J. Clulow, Andrew Nelson, Norifumi L. Yamada, Marappan Velusamy, Qingyi Yang, Furong Zhu, Paul L. Burn, Ian R. Gentle, Paul Meredith

Research output: Contribution to journalArticleResearchpeer-review

14 Citations (Scopus)


We present ITO-free rigid and flexible monolithic organic solar cells with an active area of 25 cm2. The devices employ a transparent insulator/metal/insulator anode consisting of a molybdenum oxide/silver/zinc sulfide stack that had a peak transmittance of 80% and a sheet resistance of 3.6/□. Neutron reflectometry showed that zinc sulfide formed a more stable capping layer at the air interface than molybdenum oxide. It was found that blade coating could be used to form good quality large area films on both rigid (glass) and flexible [poly(ethylene terephthalate)] substrates with much reduced material consumption. Cells with an active layer comprised of a blend of poly[N-9″-heptadecanyl-2,7-carbazole-alt-5,5-(4′, 7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM) gave a power conversion efficiency of 2.7%, which was 40% higher than a standard ITO-based device. No loss in efficiency was observed when a flexible substrate was used.

Original languageEnglish
Pages (from-to)182-190
Number of pages9
JournalSolar Energy Materials and Solar Cells
Publication statusPublished - 2014
Externally publishedYes


  • Blade coating
  • Neutron reflectometry
  • Organic photovoltaics
  • Organic semiconductors

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