Effect of multilayer structure and surface texturing on optical and electric properties of structural colored photovoltaic modules for BIPV applications

Building-integrated photovoltaics (BIPV) offer a promising approach for reducing carbon emissions in the buildings sector. In BIPV system, color control harmonizes photovoltaic modules with the architectural design and surroundings. In this paper, a structural coloring technique based on the optical interference effect of dielectric multilayers is applied to the cover glass of Si-based photovoltaic modules to realize efficient and aesthetically appealing BIPV modules. A trade-off between the color brightness and the short-circuit current density (JSC) of colored BIPV modules is found, which are highly dependent on the multilayers structure and the surface roughness of the cover glass. We also evaluate the glare-effect and the color angular dependence of these modules and find that these two obstacles can be effectively suppressed by introducing the surface texturing to the cover glass. However, roughening the glass surface can also contribute to an additional optical loss and a decrease in the JSC. Therefore, the design of structured colored glass should be adapted depending on the intended purpose. Finally, we demonstrate colored PV modules with high conversion efficiencies of >21% and minimal JSC loss of <5%, while maintaining the adequate anti-glare effect and the color angular independence.