A Cryogenic Process for Antisolvent-Free High-Performance Perovskite Solar Cells.

Area of Science:

• Materials Science
• Renewable Energy
• Chemical Engineering

Background:

• Perovskite solar cells offer high efficiency but often rely on environmentally harmful antisolvents during fabrication.
• Controlling perovskite crystallization is crucial for device performance and stability.
• Developing greener fabrication methods is essential for sustainable solar energy technologies.

Purpose of the Study:

• To introduce a cryogenic process for controlling perovskite crystallization.
• To eliminate the need for hazardous antisolvents in perovskite solar cell fabrication.
• To improve the performance and efficiency of perovskite solar cells through a novel fabrication technique.

Main Methods:

• A cryogenic process involving rapid cooling of precursor films in liquid nitrogen.
• Inhibition of chemical reactions during rapid cooling to decouple nucleation and crystallization.
• Controlled blow-drying with nitrogen gas to induce uniform precursor precipitation and solvent evaporation.
• Application of the process to various mixed halide perovskite compositions.

Main Results:

• Successful decoupling of nucleation and crystallization phases in perovskite films.
• Uniform precursor precipitation and enhanced solvent evaporation at low temperatures.
• Demonstrated applicability to three different mixed halide perovskite types.
• Achieved a champion power conversion efficiency (PCE) of 21.4% with V_OC = 1.14 V, J_SC = 23.5 mA cm^-2, and FF = 0.80.

Conclusions:

• The cryogenic process offers an environmentally friendly alternative to antisolvent methods for perovskite fabrication.
• This technique enables precise control over perovskite crystallization, leading to improved solar cell performance.
• The developed method is versatile and applicable to a range of perovskite compositions, paving the way for efficient and sustainable solar cells.