Interface-oriented bridges toward efficient carbon-based perovskite solar cells.

The perovskite/electron transport layer interface plays a critical role in perovskite solar cell (PSC) performance and stability. Here, we report potassium bisaccharate (PB) acting as a multifunctional interfacial chemical bridge at the interface between the electron transport layer and the perovskite layer on introducing it into a buried interface. The carboxyl group at one end of the molecule is anchored to the hydroxy-rich SnO surface through covalent interactions, stabilizing its out-of-plane orientation, and the carboxyl group at the other end reduces non-radiative recombination by passivating the under-coordinated Pb in the perovskite.

Ligand-Induced In Situ Epitaxial Growth of PbI Nanosheets/MAPbI Heterojunction Realizes High-Performance HTM-Free Carbon-Based MAPbI Solar Cells.

Hole-transporting layer-free carbon-based perovskite solar cells (HTL-free C-PSCs) hold great promise for photovoltaic applications due to their low cost and outstanding stability. However, the low power conversion efficiency (PCE) of HTL-free C-PSCs mainly results from grain boundaries (GBs). Here, epitaxial growth is proposed to rationally design a hybrid nanostructure of PbI nanosheets/perovskite with the desired photovoltaic properties.