Naphthalenediimides with carboxyl anchoring groups as promising components of the electron transport layer in n-i-p perovskite solar cells

A series of unsymmetrically substituted naphthalenediimide derivatives containing pendant carboxyl groups were used as a passivating coating of tin dioxide electron transport layer in n-i-p perovskite solar cells. Devices fabricated using naphthalenediimides showed competitive performances reaching 16.5% (compared to 17.6% provided by fullerene derivative PCBA) and, most importantly, demonstrated improved operational stability. These results indicate the potential for further exploration of naphthalenediimide derivatives as highly promising and cost-efficient electron transport layer materials for perovskite solar cells.