Stabilized perovskite ink for scalable coating enables high-efficiency perovskite modules

Area of Science:

• Materials Science
• Chemical Engineering
• Renewable Energy

Background:

• Perovskite inks are crucial for high-quality films and reproducible perovskite solar cell performance.
• Current cesium-formamidinium lead triiodide (Cs_xFA_1-xPbI₃) inks suffer from instability due to strong solvent-lead-halide coordination, leading to aggregation and precipitation.

Purpose of the Study:

• To address the instability of Cs_xFA_1-xPbI₃ perovskite inks.
• To identify the key factors governing ink stability and develop a more stable ink formulation.
• To improve the performance and durability of perovskite solar modules fabricated using blade-coating techniques.

Main Methods:

• Investigated the coordination strength between precursor salts and solvents in perovskite ink formulations.
• Identified solvent coordination-dispersion equilibrium as the critical factor for ink stability.
• Developed a novel stable perovskite ink by modulating solvent-precursor interactions.
• Fabricated perovskite films using blade-coating with the optimized ink.
• Characterized the resulting films and fabricated p-i-n perovskite solar modules.

Main Results:

• A stable perovskite ink with significantly increased shelf life was developed.
• The stable ink facilitated controlled ink drying and film crystallization, yielding highly uniform perovskite films with low defect density.
• Ambient-fabricated p-i-n perovskite modules achieved a power conversion efficiency (PCE) of 23.5%.
• The perovskite modules demonstrated excellent durability, retaining 99% of their initial PCE after 1700 hours of continuous operation under maximum power point tracking (ISOS-L-2 standard).

Conclusions:

• Modulating solvent coordination strength is key to achieving stable perovskite inks.
• The developed stable ink formulation enables high-quality perovskite film formation and improved device performance.
• This work offers a pathway to highly efficient and durable perovskite solar modules through enhanced ink stability.