Multifunctional Additives Suppressed Phase Segregation of Wide-Bandgap Perovskites for Semitransparent Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Metal halide perovskites with a ~1.68 eV bandgap are key for tandem solar cells.
• Incorporating Br- and Cs+ into iodide-based perovskites causes ionic size mismatches, leading to defects and instability.
• These issues compromise perovskite solar cell efficiency and operational lifespan.

Purpose of the Study:

• To develop a strategy to overcome crystallization and stability issues in metal halide perovskites.
• To improve the performance and durability of perovskite solar cells and tandem devices.
• To investigate the role of a novel multifunctional molecule in perovskite film formation.

Main Methods:

• Designed a multifunctional molecule, (S)-methyl 2-amino-3-(3,4-dihydroxyphenyl)propanoate hydrochloride (DMECl), with ester, amino, and catechol groups.
• Utilized DMECl to coordinate with Pb2+ and form hydrogen bonds with I- and FA+, regulating crystallization.
• Fabricated semi-transparent perovskite solar cells and perovskite-silicon tandem solar cells using the DMECl strategy.

Main Results:

• DMECl effectively regulated perovskite crystallization, reduced defect density, and suppressed phase segregation.
• Semi-transparent perovskite solar cells achieved a 19.7% power conversion efficiency with >85% stability after 1000 hours.
• Perovskite-silicon tandem solar cells reached a 29% power conversion efficiency.

Conclusions:

• The designed DMECl molecule significantly enhances the performance and stability of metal halide perovskite films.
• This approach offers a promising pathway for developing efficient and durable perovskite-based solar cells and tandem devices.
• DMECl-modified perovskites are crucial for advancing next-generation photovoltaic technologies.