High‐low refractive index stacks as antireflection coatings on triple‐junction solar cells

Abstract Antireflection coatings (ARCs) are crucial components of high‐efficiency solar cells. A new ARC design philosophy, dubbed high‐low refractive index stacks, has demonstrated good potential to minimize reflection losses for triple‐junction and quadruple‐junction solar cells in simulations. We have implemented such novel ARCs on GaInP/InGaAs/Ge triple‐junction solar cells and compared the experimental performances—external quantum efficiency and reflectivity—with that of identical devices equipping the classic double‐layer ARC. For typical materials such as MgF 2 /ZnS with ambient glass, the results show that the new design improves the short circuit current by 1.8% at normal incidence and 1.6% and 1% for angles of incidence of 30° and 50°, respectively.