Researchers from the University of Electronic Science and Technology of China and Chinese Academy of Sciences have examined the role of perovskite phase homogeneity, for achieving highly-efficient and mechanical-stable flexible perovskite/c-silicon heterojunction monolithic tandem solar cells (PSTs) with textured surface.
The synthesis process of perovskite on flexible textured c-Si heterojunction bottom cells. Image credit: Nature Communications
The team demonstrated highly efficient and reliable flexible perovskite/c-Si heterojunction monolithic tandem solar cells. They highlighted the critical role of phase homogeneity of perovskite films in flexible PSTs with textured substrates and found that a highly homogeneous phase distribution of perovskite films not only effectively promotes the charge transport and extraction across all facets of the pyramid on the textured substrates, but also efficiently releases the tensile stress between the perovskite layer and textured c-Si bottom cell during bending.
The optimized flexible PSTs achieved a champion certified PCE of 29.88% (steady-state 29.2%), along with superior mechanical endurance of maintaining initial efficiency after 2000 bending cycles.
Furthermore, the team demonstrated that the mechanical endurance of flexible PSTs can be extended to the fracture limit of the c-Si substrate, only when highly phase-homogeneous perovskite is achieved.
These findings could pave the way towards high-performance flexible perovskite-based solar cells for high-power-to-weight-ratio, high-conformability, and high-integrability power applications.
