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 MAPbI₃ precursor solution. Carbonyl groups in AAA coordinate with lead ions (Pb²⁺), influencing the crystallization process by binding to Pb²⁺ ions through lone pair electrons. It helps to control crystallization kinetics and passivates defects caused by under-coordinated Pb²⁺ 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.