Cost-Effective Acetonitrile-Based Precursor Solution Mitigates Heterogeneous Nucleation for Efficient and Stable...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Solution-processing is key for high-efficiency perovskite solar cells (PSCs).
• Solvent choice critically impacts perovskite film formation and quality.
• Additives can improve film formation but may cause heterogeneous nucleation and defects.

Purpose of the Study:

• To develop a cost-effective and efficient solvent system for perovskite precursor solutions.
• To investigate the impact of acetonitrile (ACN) as a weak coordination solvent on perovskite film formation and device performance.
• To enhance the stability and power conversion efficiency (PCE) of perovskite solar cells.

Main Methods:

• Developed a perovskite precursor solution using acetonitrile (ACN) as a weak coordination host solvent, replacing N,N-dimethylformamide (DMF).
• Investigated the crystallization pathway via a dimethyl sulfoxide-solvated intermediate phase to α-FAPbI₃.
• Fabricated PSCs and minimodules using the ACN-based precursor solution.

Main Results:

• The ACN-based solution reduced heterogeneous nucleation and compositional heterogeneity compared to DMF.
• Enhanced perovskite film crystallinity and reduced defect states.
• Achieved a PCE of 23.62% for PSCs and 20.13% for minimodules.
• PSCs retained over 97% efficiency after 800 hours of continuous illumination under MPPT.

Conclusions:

• Acetonitrile offers a cost-effective alternative to DMF for PSC fabrication, reducing costs by half.
• The ACN-based method promotes a single crystallization pathway, improving film quality and device performance.
• This strategy enhances PSC efficiency and long-term operational stability.