Recently, self-assembled monolayers (SAMs) have garnered significant attention in the field of perovskite solar cells (PSCs). Replacing flexible alkyl chains with conjugated linkers can significantly enhance the material's performance. Traditional conjugation modulation primarily relies on carbon-carbon double bonds (C═C), whereas the use of carbon-carbon triple bonds (C≡C) to expand the conjugated system of SAM materials has been rarely reported, and the influence of introducing triple bonds on material properties and device performance remains unclear. In this work, we design a novel donor-acceptor (D-A) structured SAM, named ABT, by incorporating a C≡C linker between the D-A moiety and the anchor group. The introduction of a C≡C bond effectively extends the conjugated system of the material, significantly enhancing its thermal stability and charge transport properties. As a result, ABT-based devices achieve a champion power conversion efficiency (PCE) of 26.19%, surpassing the reference BT-based devices (24.92%), along with exceptional thermal and long-term operational stability. This work provides a rational molecular design strategy for high-performance and stable D-A type SAMs, thereby facilitating the commercialization of PSCs.
Xia et al. (Thu,) studied this question.