Perovskite Crystallization Regulation via Antimonene Quantum Sheets for Highly Efficient and Stable Solar Cells

The two-step deposition method offers significant advantages in the production of high-performance planar perovskite solar cells (PSCs). Nevertheless, there are still numerous challenges in regulating perovskite crystallization during the two-step process. In this work, two-dimensional (2D) material antimonene quantum sheets (AMQSs) as an additive are introduced to regulate the crystallization process of perovskite. As a result, perovskite films with high crystalline quality and vertical growth orientation are obtained by AMQSs providing heterogeneous nucleation sites with the penetration of a mixture solution of AMQSs and FAI into the PbI₂ layer. Also, the influence mechanism of AMQSs on the crystallization of perovskite film is analyzed in details. At the same time, due to the chemical interaction between antimonene and the uncoordinated Pb²⁺, the defects in the perovskite are efficiently passivated. In addition, the energy level at the perovskite/SnO₂ interface becomes more matched, leading to improved charge transport and extraction with the incorporation of AMQSs. Benefiting from the versatile AMQSs, the power conversion efficiency (PCE) of PSCs made by PbI₂ + FAI:AMQSs is improved from 20.65 to 22.31% with the vastly enhanced J_sc and V_oc. The ambient and operational stability of the unencapsulated PSCs fabricated using the PbI₂ + FAI:AMQSs method were significantly improved, retaining 80% of the original PCE after being stored in a dark environment at a relative humidity of 30-40% for 18 days and 83% of the original PCE following continuous AM 1.5G illumination for 200 h.