Multifunctional acetoacetanilide additive strategy for enhanced efficiency and stability in perovskite solar cells.

Perovskite solar cells (PSCs) have garnered tremendous interest for their cost-effective solution-based fabrication process and impressive power conversion efficiency (PCE). The performance and stability of PSCs are closely tied to the quality of the perovskite film. Additive engineering has emerged as a highly effective strategy to achieve stable and efficient PSCs. In this study, acetoacetanilide (AAA), containing amide and carbonyl groups, is introduced for the first time as a multifunctional agent to the MAPbI precursor solution. Carbonyl groups in AAA coordinate with lead ions (Pb), influencing the crystallization process by binding to Pb ions through lone pair electrons. It helps to control crystallization kinetics and passivates defects caused by under-coordinated Pb ions. Simultaneously, the amide groups strongly interact with iodide ions (I), stabilizing them and suppressing ion migration, which reduces defect vacancies in the perovskite structure. Incorporating AAA led to a significant improvement in PCE, increasing from 16.93% in the untreated device to 20.1% in the AAA-treated devices. Furthermore, the AAA-treated devices showed more stability behavior against humidity and light. These findings underscore the potential of AAA as a high-performing additive for advancing the PCE and stability of PSCs.