Minimizing Buried Interface Energy Losses with Post-Assembled Chelating Molecular Bridges for High-Performance and...

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Self-assembled monolayers (SAMs) are crucial for hole collection in inverted perovskite solar cells (PSCs).
• Challenges include incomplete SAM coverage and poor perovskite/SAM interface contact, leading to energy losses.
• Optimizing the buried interface is key to improving PSC performance.

Purpose of the Study:

• To develop a post-assembled chelating molecular bridge strategy to modify the perovskite/SAM buried interface in inverted PSCs.
• To enhance interface characteristics, promote carrier extraction, and improve the overall performance and stability of PSCs.
• To address the limitations of incomplete SAM coverage and non-intimate interface contact.

Main Methods:

• A post-assembled chelating molecular bridge strategy using 5-(9H-carbazol-9-yl)isophthalicacid (CB-PA) was employed.
• CB-PA was chemically coupled with MeO-2PACz via π-π stacking and chelated with perovskite through C═O···Pb bonds.
• The method involved filling voids in SAMs to create dense hybrid layers and analyzing the effects on perovskite crystallization and defect passivation.

Main Results:

• The CB-PA molecular bridge promoted efficient carrier extraction and improved interface contact by forming dense hybrid SAMs.
• CB-PA treatment led to oriented perovskite crystallization, interface defect passivation, and reduced lattice stress.
• CB-PA-based inverted PSCs achieved a champion power conversion efficiency of 25.27%.

Conclusions:

• The post-assembled chelating molecular bridge strategy effectively addresses buried interface challenges in inverted PSCs.
• This approach significantly enhances both the efficiency and operational stability of perovskite solar cells.
• The developed method offers a promising pathway for high-performance and durable perovskite solar cell devices.