Sequential Evaporation for Scalable Hybrid Processing of Perovskite/Silicon Tandem Solar Cells
byLorenzo Mardegan, Mingjie He, Badri Vishal, Thomas Allen, Anand Selvin Subbiah, Anil R. Pininti, Martin Bivour, Juliane Borchert, Ahmed A. Said, Stefaan De Wolf
ArticleYear:2026
Abstract
The conformal coating of perovskites on textured silicon for tandem solar cells requires scalable deposition methods, for which hybrid vacuum-solution processing, using an evaporated inorganic scaffold (Pb/Cs halides) followed by solution conversion, is promising. Yet multisource coevaporation of the scaffold, as commonly used for lab-scale devices, is complex and costly to implement at an industrial scale. Here, we investigate sequential single-source evaporation of the inorganic scaffold as an industrially viable alternative. Five sequentially evaporated scaffold stacks were compared to a coevaporated reference. Despite differences in PbI2 conversion, halide distribution, and morphology, all showed similar single-junction device power conversion efficiencies (∼19%). The best scaffold (a PbI2/CsBr/PbI2/CsBr/PbI2 stack) achieved 28.4% in perovskite/silicon tandems without molecular additives, matching the coevaporated reference (28.3%). This work demonstrates that sequential deposition of the inorganic scaffold offers a scalable route to high-efficiency tandems.