Dual Passivation of Perovskite and SnO₂ for High-Efficiency MAPbI₃ Perovskite Solar Cells.

ABSTRACT: So far, most techniques for modifying perovskite solar cells (PSCs) focus on either the perovskite or electron transport layer (ETL). For the sake of comprehensively improving device performance, a dual-functional method of simultaneously passivating trap defects in both the perovskite and ETL films is proposed that utilizes guidable transfer of Eu³⁺ in SnO₂ to perovskite. Europium ions are distributed throughout the SnO₂ film during the formation process of SnO₂, and they can diffuse directionally through the SnO₂/perovskite interface into the perovskite, while most of the europium ions remain at the interface. Under the synergistic effect of distributed Eu³⁺ in the SnO₂ and aggregated Eu³⁺ at the interface, the electron mobilities of ETLs are evidently improved. Meanwhile, diffused Eu³⁺ ions passivate the perovskite to reduce trap densities at the grain boundaries, which can dramatically elevate the open-circuit voltage (V _oc) of PSCs. Finally, the mainly PSCs coated on SnO₂:Eu³⁺ ETL achieve a power conversion efficiency of 20.14%. Moreover, an unsealed device degrades by only 13% after exposure to ambient atmosphere for 84 days.

SUBMITTER: Chen Y 

PROVIDER: S-EPMC7927604 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature