Breaking the color-efficiency trade-off: aesthetic rainbow organic-silicon solar cell.

Imparting vivid colors to photovoltaic devices has traditionally required sacrificing power conversion efficiency, a trade-off that limits their adoption in building-integrated photovoltaics (BIPV) and other aesthetics-driven applications. Here, we overcome this constraint by integrating short-range correlated disordered dielectric nanostructures onto high-efficiency organic-silicon heterojunction solar cells. These wavelength-scale nanospheres act dually to suppress broadband specular reflection, thereby enhancing light harvesting, and to generate coherent off-specular scattering that yields iridescent structural colors. To explore this mechanism, we developed a large-scale theoretical framework that decouples collective disorder from single-particle scattering responses, enabling quantitative prediction of the color-efficiency interplay in assemblies of more than 2000 nanoparticles. Experimentally, the iridescent device achieves a power conversion efficiency of 8.17%, compared with 7.3% for the reference device without PS nanospheres, while exhibiting high-saturation CIE 1931 color coordinates. This work demonstrates that vivid coloration does not require strong reflection, overturning the long-standing efficiency-aesthetics trade-off and opening pathways to next-generation BIPV that combine performance with visual appeal.