Efficient zinc sulfide cathode layers for organic photovoltaic applications via n-type doping

摘要

We demonstrate efficient zinc sulfide cathode window layers in thin-film organic photovoltaics enabled by n-type doping zinc sulfide (ZnS) with aluminum sulfide (Al2S3) directly through co-deposition. By optimizing the Al2S3 concentration, the power conversion efficiency is improved from 0.6% ± 0.2% in undoped ZnS window layer devices to 1.8% ± 0.1%, identical to control devices. The mechanism for this performance enhancement is shown to stem from the enhanced conductivity and interface energetics of ZnS upon n-type doping. This work expands the catalog of efficient, inorganic, non-toxic, cathode side window layers that could be effective in a range of thin-film photovoltaic technologies.