High performance and low cost transparent electrodes based on ultrathin Cu layer.

Transparent electrodes based on an ultrathin Cu layer, embedded between two dielectrics, are optimized by simulations and experiments. Different dielectrics are screened in transfer matrix simulations for maximizing the broad-band transmittance. Based on this, sputtered electrodes were developed with the Cu embedded between TiO_X-coated glass or PET substrate and an Al-doped ZnO (AZO) top layer. It is found that, for ultrathin Cu layers, increased sputter power fosters island coalescence, leading to superior optical and electrical performance compared to previously reported Cu-based electrodes. Simulations showed that the electrode design optimized with air as ambient medium has to be adapted in the case of electrode implementation in a hybrid perovskite solar cell of inverted architecture.