Cation-Anion Synergy Enables Uniform and Stable SAMs for High-Efficiency Perovskite/TOPCon Tandem Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Hole-selective self-assembled monolayers (SAMs) enhance perovskite/silicon tandem solar cell (TSC) efficiency.
• Challenges exist in forming dense, uniform, and stable SAMs on textured surfaces for advanced solar devices.

Purpose of the Study:

• To develop a synergistic strategy for improved SAMs and perovskite absorber quality.
• To enhance molecular anchoring stability and interfacial contact in TSCs.
• To achieve high power conversion efficiency (PCE) and operational stability in perovskite-based solar cells.

Main Methods:

• Employed a cation-anion synergistic strategy to suppress SAMs clustering.
• Utilized cation-π interaction and phosphonic acid deprotonation for SAM formation.
• Fabricated wide-bandgap perovskite solar cells and perovskite/silicon tandem solar cells on textured tunnel oxide passivated contacts (TOPCon).

Main Results:

• Achieved a PCE of 23.04% for wide-bandgap perovskite solar cells, with 84% retention after 1500 hours of stability testing.
• Demonstrated a 1 cm² monolithic perovskite/silicon tandem solar cell with a record 32.13% PCE.
• Confirmed enhanced interfacial contact and molecular anchoring stability through the synergistic strategy.

Conclusions:

• The cation-anion synergistic strategy effectively improves SAM quality and stability for perovskite solar cells.
• This approach leads to high-performance and durable perovskite/silicon tandem solar cells.
• The developed method sets a new benchmark for perovskite/TOPCon tandem solar cell efficiency.