ITO-free large-area flexible organic solar cells with an embedded metal grid

Embedded thick metal grids on flexible substrates allow uniform spin coating of thin layers of PEDOT:PSS (PH1000) semitransparent electrodes and organic semiconductor layers. Inverted solar cells with an active area of 9.3 ± 0.2 cm2, exhibited a fill factor of 0.53 ± 0.06, and an open-circuit voltage of 808 ± 5 mV and a short-circuit current density of 5.5 ± 0.5 mA/cm2, yielding a power conversion efficiency of 2.4 ± 0.4% under 100 mW/cm2 AM 1.5G illumination.