RESUMEN
The performance and scalability of perovskite solar cells (PSCs) based on 3D formamidinium lead triiodide (FAPbI3) absorber are often hindered by defects at the surface and grain boundaries of the perovskite. To address this, the study demonstrates the use of pyrrolidinium iodide for the in situ formation of an energetically aligned 1D pyrrolidinium lead triiodide (PyPbI3) capping layer over the 3D FAbI3 perovskite. The thermodynamically stable PyPbI3 perovskitoids, formed through cation exchange reactions, effectively reduce surface and grain boundary defects in the FAPbI3 perovskite. In addition to improved phase stability, the resulting 1D/3D perovskite film forms a cascade energy band alignment with the other functional layers in PSCs, enabling a barrier-free interfacial charge transport. With a maximum power conversion efficiency (PCE) of ≈23.1% and ≈20.7% at active areas of 0.09 and 1.05 cm2, respectively, the 1D/3D PSCs demonstrate excellent performance and scalability. Leveraging this improved scalability, the study has successfully developed a mechanically-scribed 1D/3D perovskite mini-module with an unprecedentedly high PCE of ≈20.6% and a total power output of ≈270 mW at an active area of ≈13.0 cm2. The 1D/3D multi-dimensional perovskite film developed herein holds great promise for producing low-cost, high-performance perovskite photovoltaics at both the cell and module levels.
RESUMEN
The development of anti-solvent free, scalable, and printable perovskite film is crucial to realizing the low-cost roll-to-roll development of perovskite solar cells (PSCs). Herein, large-area perovskite film fabrication is explored using a spray-assisted sequential deposition technique. How propylene carbonate (PC) solvent additive affects the transformation of lead halide (PbI2 ) into perovskite at room temperature is investigated. The result shows that PC-modified perovskite films exhibit a uniform, pinhole-free morphology with oriented grains compared with pristine perovskite films. The PC-modified perovskite film also has a prolonged fluorescence lifetime that indicates lower carrier recombination. The champion PSC devices based on PC-modified perovskite film realize a power conversion efficiency (PCE) of 20.5% and 19.3% at an active area (A) of 0.09 cm2 and 1 cm2 , respectively. The fabricated PSCs are stable and demonstrate ≥85% PCE retention following 60 days of exposure to ambient conditions. Furthermore, perovskite solar modules (A ≈ 13 cm2 ) that yield a PCE of 15.8% are fabricated. These results are among the best reported for the state-of-art spray-coated PSCs. Spray deposition coupled with a PC additive is highly promising for economical and high-output preparation of PSCs.