A Triphenylamine-Functionalized Co-Assembly Material for Record Efficiency Inverted CsPbI3 Perovskite Solar Cells.

High quality distribution and surface modification of self-assembled monolayer (SAM) is crucial for enhancing the efficiency and stability of p-i-n inverted perovskite solar cells (PSCs). In this work, a new co-assembly material, 4-(aminomethyl)-N,N-diphenylaniline iodide (TPAI), is developed to make SAMs orderly assembled. Density functional theory (DFT) calculation and sum frequency generation (SFG) characterization unveil that TPAI can bind with SAMs through π-π interactions to effectively diminish SAMs aggregation and improve the orderly assembly of SAMs.