Photonic-Enhanced Perovskite Solar Cells: Tailoring Color and Light Capture.

The current exponential growth of solar electricity technologies toward consumer-oriented applications, as in building- or vehicle-integrated photovoltaics (B/VIPV), is calling for improved solar cells, not only in cost-effectiveness, but also with better adaptability and aesthetics. Here, using perovskite solar cells (PSCs) as test bed, we demonstrate an unprecedented photonic method to generate any color on a cell layout, while also increasing PV efficiency. To this end, photonic surface features were designed for PSCs, which filled the dual purpose of light-trapping (LT) and modulation of reflected light interference. A variety of geometries, from simple gratings to complex semispheroids, were optically optimized for two of the most challenging colors, magenta and green, while assuring the generation of their maximum feasible photocurrent. The best results corresponded to a current density of 22.07 mA/cm, obtained for the magenta solar cell with top domes, exhibiting an increase of 6.68%, relative to an optimized planar reference cell. In turn, the same type of geometry was able to generate the leading green cell, with up to 21.40 mA/cm (a relative increase of 3.44%). Additionally, the uniformity of the optical output of the optimal solar cells was tested under a range of incident light angles, between 0 and 60, where the current density suffered relative losses only down to 6.65%.