Dual-functional 1-adamantanethiol additive engineering for efficient and stable perovskite solar cells

Perovskite solar cells (PSCs) feature the superiority of low-cost and convenient fabrication. Yet it is still a challenge to solve the malady of defect passivation and environmental stability of PSC devices. Functional additives were introduced during the crystallization and film formation of perovskite, and it has become a promising route to improve the efficiency and stability of PSC devices. Here, we introduce a dual-functional additive, 1-adamantanethiol (ADSH), into the perovskite film. In ADSH, the sulfur-containing thiol group functions as a Lewis base, coordinating the under-coordinated Pb²⁺ ions, also the rigid and hydrophobic adamantane framework can be regarded as a barrier against moisture ingress. The characterization shows that by using ADSH additive, the perovskite film was improved. Finally, the ADSH-modified device scored a power conversion efficiency (PCE) of 25.31%, and stably operated over 800 h.