Spacer Regulation of the Novel Pyrene-Based Tetrapodal Self-Assembled Monolayers for Efficient and Stable Inverted...

Multipodal self-assembled monolayers (SAMs) composed of π-conjugated aromatic units have emerged as highly promising hole-transporting layers in perovskite solar cells (PSCs) due to their excellent interfacial anchoring and scalable fabrication. However, it remains a formidable challenge to develop high-performance tetrapodal SAMs that can simultaneously achieve ideal surface coverage, enhanced device efficiency, and improved long-term stability. Herein, we rationally designed and synthesized two novel pyrene-centered tetrapodal SAMs, 4PACz-Py-C2 and 4PACz-Py-C4. Spacer engineering has been employed to regulate molecular packing, facilitate hole extraction, and suppress non-radiative recombination. The optimized PSCs based on 4PACz-Py-C2 achieved a power conversion efficiency (PCE) of 26.61% and maintained 90.1% of their initial PCE after 2000 h of maximum power point (MPP) tracking, demonstrating outstanding commercialization potential. Moreover, perovskite solar modules (aperture area: 21 cm²) and 1.68 eV wide-bandgap perovskite devices based on 4PACz-Py-C2 yielded high PCEs of 23.52% and 23.48%, respectively. This work exhibits significant application value in the development of novel multipodal SAMs for enhancing the efficiency and stability of PSCs.