Boron subnaphthalocyanine additive for multilocus passivation of defects towards efficient and stable perovskite solar cells

Abstract

Shallow and deep level defects often act as a pathway of ion migration and Shockley–Read–Hall recombination centers, respectively, in semiconductor materials, degrading the photoelectric performance and long-term stability of assembled photovoltaic devices. In this study, we introduce a novel semiconductive boron subnaphthalocyanine derivative (B-SubPc-F) with multi-functional groups into the surface and shallow layer of the perovskite film to further enhance the performance and stability of perovskite solar cells (PSCs). As a positive consequence, the detrimental defects of Pb_I anti-site defects and iodide vacancies are effectively passivated, while simultaneously modifying the energetic positions at the perovskite/spiro-OMeTAD interface to facilitate charge transport. As a result, the PSCs treated with B-SubPc-F exhibit an outstanding PCE of 23.35%, significantly surpassing that of the control device (21.75%). Additionally, the B-SubPc-F-treated PSCs exhibit superior moisture and thermal stability, with devices retaining 78% of their initial efficiency after being subjected to 348 h at 85 °C w/o encapsulation, in contrast to the control device, which retained only 16% of its PCE after thermal aging under the same conditions.