Precursor-Engineered Volatile Inks Enable Reliable Blade-Coating of Cesium-Formamidinium Perovskites Toward Fully...

Area of Science:

• Materials Science
• Renewable Energy

Background:

• Antisolvent-free printing of perovskite solar cells typically requires volatile solvents like 2-methoxyethanol (2ME).
• High-quality cesium-formamidinium (Cs-FA) perovskite fabrication is challenging with volatile solvents due to poor precursor coordination.

Purpose of the Study:

• To resolve the challenge of fabricating high-quality Cs-FA perovskites using volatile solvents.
• To develop a reliable, scalable, and cost-effective method for perovskite solar cell production.

Main Methods:

• Re-formulated a 2ME-based Cs$_{0.05}$FA$_{0.95}$PbI$_{3}$ ink using pre-synthesized single crystals instead of raw powders.
• Removed colloidal particles from the ink to suppress heterogeneous nucleation and promote crystal growth.
• Employed vacuum-free, fully printed processing for solar cell fabrication with a carbon electrode.

Main Results:

• Achieved a power conversion efficiency (PCE) of 19.3% for printed solar cells.
• Demonstrated excellent operational stability with T$_{80}$ of 1000 hours under ISOS-L-2I conditions (85 °C/1 Sun).
• Fabricated carbon-electrode mini solar modules with a stabilized average PCE of 15.6%, a record for fully printed devices.

Conclusions:

• Precursor engineering with single crystals in volatile inks enables high-quality Cs-FA film formation.
• The antisolvent-free printing methodology is crucial for scalable and cost-effective perovskite solar cell manufacturing.
• This approach represents a significant milestone towards achieving scalable photovoltaic technology.