Solvent-Antisolvent Ambient Processed Large Grain Size Perovskite Thin Films for High-Performance Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Hybrid organic-inorganic halide perovskites are vital for low-cost optoelectronic devices, especially solar cells.
• Perovskite film microstructure significantly impacts device performance.
• A cost-effective ambient processing technique for microstructure control is lacking.

Purpose of the Study:

• To develop a simple, robust solvent engineering technique for ambient processing of perovskite films.
• To achieve large grain size, high crystalline quality, and low pinhole density in perovskite thin films.
• To investigate the impact of microstructure on the performance of perovskite solar cells.

Main Methods:

• Solvent-antisolvent processing of CH3NH3PbI3-xClx based thin films under ambient conditions.
• Utilizing a specific solvent mixture (75% chlorobenzene and 25% ethanol) for optimized film formation.
• Fabrication and characterization of planar perovskite solar cells.

Main Results:

• Achieved large perovskite grains (>5 µm) with excellent crystalline quality and surface coverage (>99.97%).
• Demonstrated very low pinhole density in the processed perovskite films.
• Produced planar perovskite solar cells with power conversion efficiencies (PCEs) up to 14.0%.

Conclusions:

• Solvent engineering is a promising technique for ambient processing of high-quality perovskite films.
• Minimizing pinholes and controlling grain size are critical for high-performance perovskite solar cells.
• This method facilitates the optimization of large-area thin films for efficient solar energy conversion.