Hybrid Ag Nanowire–ITO as Transparent Conductive Electrode for Pure Sulfide Kesterite Cu2ZnSnS4 Solar Cells

Abstract

We present the hybrid silver nanowire network–ultrathin ITO as the transparent conductive electrode for earth-abundant and environmentally friendly pure sulfide Cu2ZnSnS4 solar cells, replacing the scarce and expensive ITO. For this new hybrid transparent electrode, sputtered intrinsic zinc oxide is introduced as an antireflective coating replacing MgF2 in traditional Cu2ZnSnS4 solar cells. Random arrays of silver nanowire network with different densities hybridized with 20 nm ITO layer are employed in Cu2ZnSnS4 devices and their device performance is compared with the reference device with conventional ITO electrode. The devices with the hybrid electrodes with similar sheet resistance to ITO show generally improved current density due to their better optical transparency than ITO while maintaining similar fill factor. Cu2ZnSnS4 devices with low density Ag nanowire hybrid electrode give the highest efficiency of 6.4% on average mainly due to improved current density, among which the highest efficiency va...