Dual-SAM/Al₂O₃-Nanoparticles Hole-Selective Stack With BCP/PEAI Passivation Enabling High Performance Inverted...

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Single-layer self-assembled monolayers (SAMs) in perovskite solar cells (PSCs) face challenges in balancing carrier extraction and device stability.
• Hole-selective SAMs are crucial for high-performance inverted PSCs.

Purpose of the Study:

• To develop a dual-interface architecture for improved efficiency and stability in inverted PSCs.
• To address limitations of conventional single-layer SAMs in PSCs.

Main Methods:

• Designed a dual-interface architecture with alumina nanoparticles (Al2O3-NPs) sandwiched between two phosphonic acid-based SAMs.
• Incorporated a BCP/PEAI bilayer overlayer to passivate perovskite surface defects and enhance electron extraction.
• Investigated the role of Al-O-P bridging linkages and π-π stacking interactions.

Main Results:

• Achieved a champion power conversion efficiency (PCE) of 25.13% with a fill factor of 82.6%.
• Demonstrated negligible hysteresis and significant device stability with 73.8% PCE retention after 2700 hours of ambient storage.
• The dual-interface architecture effectively sealed pinholes, balanced charge transport, and suppressed non-radiative recombination.

Conclusions:

• The dual-interface molecular engineering strategy offers a pathway to highly efficient and stable PSCs.
• Al2O3-NPs and phosphonic acid SAMs synergistically enhance device performance.
• The BCP/PEAI overlayer further contributes to defect passivation and improved charge extraction.