Single-Atom Effect on the Regulation of Buried Interface for Self-Assembled Molecules in Inverted Perovskite Solar Cells

Abstract

Although the self-assembled molecules (SAMs) have shown great potential in boosting the device performance of inverted perovskite solar cells (PSCs) during the past years, the molecular design strategies are particularly varied with equivocal design principles due to the strikingly different molecular structures and the resultant properties. Herein, we designed and developed a series of SAMs featuring nearly identical structure and differing by only a single atom (from O atom to S and Se atom). It was found that the corresponding SAMs POZ-PA, POT-PA and POSe-PA show distinct molecular configurations and properties. POZ-PA containing O atom possesses relatively planar structure, more dense self-assembling film and superior interface properties such as well-matched energy level alignment, excellent passivation capacity and optimized charge dynamics. Consequently, a champion power conversion efficiency of 22.23% is realized for POZ-PA-based PSCs along with good storage and thermal stability. This work provides a more precise molecular design strategy to better investigate the structure-property-performance relationship and give guidance for the development of efficient and stable hole-selective materials.