Efficient colored silicon solar modules using integrated resonant dielectric nanoscatterers

Abstract

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, and 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 road for designing efficient colorful or white building-integrated photovoltaics.