Recent advances in ionic molecules applied in perovskite solar cells

Abstract

Perovskite solar cells (PSCs) have emerged as the most promising photovoltaic technology owing to their advantages of high efficiency and roll-to-roll compatibility. In the past year, many efforts have been dedicated to further improving the device performance, especially the incorporation of various organic ionic molecules, mainly because of the strong interactions between the ionic groups and perovskite components. In this review, initially, we provide a specific analysis of the interaction types in these works, including electrostatic interactions and hydrogen and coordinate bonds. Subsequently, the functions and mechanisms of these ionic molecules are comprehensively categorized, including defect passivation, crystalline regulation, interfacial band alignment and atmospheric protection. Finally, a summary of the current challenges and some suggestions on future studies are proposed. This review aims to provide important insights into the design of ionic materials for high-performance PSCs.