Highly Efficient, Mechanically Flexible, Semi‐Transparent Organic Solar Cells Doctor Bladed from Non‐Halogenated Solvents

Abstract

All‐solution deposited, ITO‐free organic solar cells comprising hybrid top and bottom electrodes and ternary polymer:fullerene photo‐active layers are investigated. A printed micro silver mesh and conductive PEDOT:PSS are employed as bottom electrode on a mechanically flexible PET substrate, whereas the top electrode features highly conductive PEDOT:PSS with dispersed silver nanowires. The highly efficient ternary polymer:fullerene absorber blend PffBT4T‐2OD:PC 61 BM:PC 71 BM and all other functional layers are doctor bladed from non‐halogenated solvents in order to comply with the requirements of industrial device fabrication. The semi‐transparent solar cells yield maximum power conversion efficiencies of 6.6% on active areas ≤ 0.1 cm 2 and 5.9% on active areas > 1 cm 2 . Omitting additional bus bars for charge extraction grants the solar cells a homogeneous appearance and transparency perception.