Tunable and angle-insensitive structural coloring of solar cell modules for high performance building-integrated photovoltaic application

Abstract

Building-integrated photovoltaics (BIPV) is desired to reduce carbon emissions from residential and commercial buildings. In this application, the controlling the visual impact of BIPV module with preserving PV performance remains a great challenge since the appearance of conventional PV modules is not favorable for building skins in most cases because of their dark colors. In this paper, we report on the color control of crystalline silicon (c-Si) PV modules by introducing the structural colors based on the interference effect. We apply the structural colors to the cover glass of PV minimodules with textured surfaces. The glass texturing is realized by sandblasting technique that allows us to form various textured surfaces depending on sandblasting conditions. High flexibility of structural colors is demonstrated by realizing various colors including violet, cyan, green, and orange using dielectric multilayers deposited on planar and textured glass sheets. These colored glass sheets are applied to c-Si PV minimodules, which exhibit high efficiencies (>18%) with distinct colors. The efficiency of colored PV minimodules depends strongly on their colors, as the efficiency loss originates solely from the optical loss by the colored glasses. In addition, the color difference at various view angles is evaluated by reflectance measurement with an integral sphere and compared in a CIE color system. It clarifies that surface texturing by sandblasting mitigates the angular dependence of structural colors substantially, which is also observable by our eyes. Besides, surface texturing is effective to mitigate the glare effect as well. Therefore, the combination of structural colors and surface texturing is a promising way to realize fascinating colors and a high energy yield simultaneously in BIPV modules. • We investigate the structural color technology to develop colorful building-integrated photovoltaics (BIPV). • Violet, cyan, green, and orange modules are achieved with high efficiencies over 18%. • The efficiency loss originates solely from the optical loss by the colored glasses. • The textured colored glasses mitigate the angular dependence of colors substantially as well as the glare effect.