Amidinopyridine Ion Docking in Crown Ether Cavity to Modulate the Top Interface in Inverted Perovskite Solar Cells

Abstract

The formation of electric dipoles at the buried interface through self-assembled molecules is crucial for minimizing non-radiative recombination and improving the efficiency of inverted perovskite solar cells. However, creating dipoles at the upper interface has seldom been reported in the literature, primarily due to the scarcity of suitable n-type organic passivants, film sensitivity of perovskite, and chemisorption issues. In this study, a novel bimolecular host–guest strategy is proposed utilizing the cavity of crown ether as the host and the ammonia ion as the guest. The ion-docking phenomenon is thoroughly examined through a comprehensive range of experimental characterizations and theoretical analyses, instilling confidence in the robustness of the findings. These findings demonstrate that the host–guest electrostatic interlocking induces an electric dipole at the perovskite surface, which facilitates electron extraction and prevents hole recombination. As a result, a power conversion efficiency of 25.25% is achieved with minimal photovoltage and non-radiative recombination losses. The target devices also exhibited superior long-term stabilities under high humid and high temperature environments.