Double Layer and High–Low Refractive Index Stacks Antireflecting Coatings for Multijunction Perovskite-on-Silicon Solar Cells

The progress toward high-efficiency and low-cost photovoltaics is currently driven by the development of multijunction perovskite-on-silicon solar cells. In many cases, these devices use relatively simple single-layer antireflection coatings formed by a low-index optical material. In this article, we analyze the potential of improving such antireflecting coatings (ARCs) using two optical materials. To this end, we assess four material combinations, namely, [LiF/ZnS], [MgF
₂
/ZnS], [LiF/Al
₂
O
₃
], and [MgF
₂
/Al
₂
O
₃
], and determine under which conditions ARCs more complex than the single-layer (as the double-layer) provide any advantages. Finally, we introduce the high–low refractive index stack methodology for the design of broadband antireflection coatings that can produce net short-circuit current density gains in all material combinations studied, with maximum increments of 1.7%.