Synchronous Interfacial and Crystallographic Engineering of Wide-Bandgap Perovskites for Efficient Perovskite/Silicon Tandem Solar Cells

Sufficient interfacial contact with a self-assembled molecule (SAM) hole-selective layer is critical for achieving optimal wide-bandgap (WBG) (1.68 eV) perovskite solar cells (PSCs) and high-efficiency tandem photovoltaics. Herein, we report a novel multifunctional molecule, TMTEA, featuring a triazole aromatic ring and terminal quaternary ammonium moiety to implement a high molecular dipole moment and strong interfacial chemical interactions. The introduction of TMTEA synergistically optimizes SAM packing on the substrate, resulting in a smooth and homogeneous surface, tailored energy-level alignment, and enhanced charge extraction. Simultaneously, TMTEA induces preferentially oriented perovskite crystallization and effectively passivates bulk defects. As a result, the TMTEA-modified WBG PSCs deliver a champion power conversion efficiency (PCE) of 23.93% with a markedly improved device stability. Furthermore, when integrated into monolithic perovskite/silicon tandem solar cells, the strategy enables a promising efficiency of 32.15%.