Dual-Functional Formic Acid Directs α-Phase Perovskite Microcrystals From Industrial Precursors for High-Yield and...

Area of Science:

• Materials Science
• Renewable Energy
• Crystallization Engineering

Background:

• Solution-processed perovskite solar cells (PSCs) face scalability challenges due to high-purity material costs.
• Developing cost-effective fabrication methods is crucial for commercializing PSC technology.

Purpose of the Study:

• To develop an efficient and scalable strategy for synthesizing FAPbI3-based perovskite microcrystals (MCs) from industrial-grade precursors.
• To investigate the role of formic acid (HCOOH) as a multifunctional additive in the crystallization process.

Main Methods:

• Utilized a synergistic process combining inverse temperature crystallization (ITC) and antisolvent-assisted precipitation.
• Employed formic acid (HCOOH) as both an additive and antisolvent with industrial-grade precursors.
• Conducted in-situ grazing-incidence wide-angle X-ray scattering (GIWAXS) to analyze crystallization dynamics.

Main Results:

• Achieved a 92.83% yield of α-FAPbI3 MCs using an optimal HCOOH concentration (40%-60% v/v).
• Formate anions (HCOO-) were shown to coordinate with Pb2+, regulating crystallization and passivating defects.
• Optimized MCs led to improved thin-film morphology, crystallinity, and charge carrier properties, resulting in a 25.24% power conversion efficiency in inverted PSCs.

Conclusions:

• Demonstrated a cost-effective and scalable route for producing high-quality perovskite materials from industrial precursors.
• Provided mechanistic insights into the dual role of HCOOH in perovskite crystallization and defect passivation.
• Offered valuable guidance for advancing low-cost, high-performance perovskite photovoltaic technologies.