Bifacial Diffuse Absorptance of Semitransparent Microstructured Perovskite Solar Cells.

An optical radiometry technique enabling simultaneous transmittance and reflectance measurements from both sides of a device was used to investigate bifacial diffuse absorptance of neutral-color semitransparent perovskite solar cells based on a thin film of microsized perovskite islands. In such microstructured solar cells diffuse irradiance was more effectively absorbed than direct irradiance at near-normal incidence, in contrast to reference solar cells comprising a continuous perovskite thin film. Experimental findings were discussed in ray-optics approximation in relation to the surface texture of the active layer, highlighting the role of light trapping. This absorptance spectroscopy technique is envisaged to find wide applicability to bifacial solar cells for building-integrated photovoltaics and other bifacial light harvesting systems.