Researchers from Zhejiang University and Aiko Solar Energy Technology have explained that while perovskite/silicon tandem PVs are attractive, achieving an efficient tandem architecture that leverages industrially textured silicon (ITS) with pyramid sizes larger than 2 μm remains a significant challenge. Such textured surfaces complicate the uniform coverage of the subsequent hole-selective layer deposition and the high-quality deposition of perovskites, ultimately causing significant contact losses in tandem devices.
In their recent work, the scientists presented a tandem solar cell architecture that uses localized submicron contacts, enabled by silica (SiOX) nanospheres, to effectively regulate silicon substrate surfaces that exhibit iceberg-like pyramids.
This architecture facilitates the complete coverage of solution-processed perovskites on ITS substrates while substantially reducing interfacial recombination losses and enhancing charge carrier transport.
Consequently, the developed tandem solar cells demonstrated certified power conversion efficiencies of up to 33.15% in a one square centimeter area, along with improved device stability. The team noted that this is the highest reported to date for monolithic perovskite-silicon tandem solar cells utilizing ITS.
Also, they found that the buried interface of perovskites at bottom of pyramid valleys was strengthened in the tandems, demonstrating superior stability compared to tandems with submicron textured silicon.
This approach, which harnesses localized submicron contacts facilitated by SiOX nanospheres to create a tandem architecture, allows for the formation of a SAM layer, followed by the integration of solution-processed perovskites on ITS substrates. The resulting devices exhibit high efficiencies and enhanced stability, positioning them as promising candidates for the commercialization of perovskite-silicon tandem solar cells. This research paves the way for further exploration and advancements in this dynamic field.
