Efficient colored silicon solar modules using integrated resonant dielectric nanoscatterers

We demonstrate photovoltaic modules with a bright green color based on silicon heterojunction solar cells integrated with arrays of light scattering dielectric nanoscatterers. Dense arrays of crystalline silicon nanocylinders, 100-120 nm wide, 240 nm tall, 325 nm pitch, are made onto module cover slides using substrate-conformal soft-imprint lithography. Strong electric and magnetic dipolar Mie resonances with a narrow linewidth (Q∼30) cause strong (35-40%) specular light scattering on resonance (∼540 nm). The green color is observed over a wide range of angles (8-75∼). As the resonant nanoscatterers are transparent for the major fraction of the incident solar spectrum the relative loss in short-circuit current is only 10-11%. The soft-imprinted nanopatterns can be applied on full-size solar modules, and integrated with conventional module encapsulation. The dielectric Mie resonances can be controlled by geometry, opening up a new road for designing efficient colorful or white building-integrated photovoltaics.