Coloured and Semi-Transparent Nanowire-based Solar Cells for Building Integrated Photovoltaics

Semi-transparent photovoltaics (ST-PV) provide smart spatial solutions to integrate solar cells into already-built areas. Here, we study the potential of semiconductor nanowires (NWs) as promising ST-PV. We perform FDTD simulations for different PV materials in a wide range of array geometries, from which we compute PV performance next to perceived appearance. Surprisingly we find an unusual compromise between photocurrent and transmittance as a function of NW diameter that enables NW-based PV to outperform theoretical limits of non-wavelength selective ST-PV. We theoretically and experimentally demonstrate the robustness of NW arrays to different illumination conditions. We provide the origin behind the outperforming NW array geometries, which is crucial for designing NW-based ST-PV systems based on specific needs.