Synergistic ECM-TTPBr/PCBA Dual-Molecule Buried-Interface Passivation Enables Highly Efficient Planar Carbon-Based...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) offer high efficiency but face stability challenges.
• Interface engineering is crucial for optimizing charge transport and reducing defects in PSCs.
• Developing stable, efficient, and industrially viable PSCs remains a key research goal.

Purpose of the Study:

• To introduce a novel copassivation strategy using ethoxycarbonyl triphenylphosphonium bromide (ECM-TTPBr).
• To enhance the solubility of [6,6]-phenyl-C61-butyric acid (PCBA) for uniform electron transport layer (ETL) coverage.
• To improve the interface between the ETL and perovskite layer for higher device efficiency and stability.

Main Methods:

• Utilizing ECM-TTPBr as a copassivator to improve PCBA solubility in chlorobenzene.
• Applying a dual-molecule copassivation effect to optimize the ETL-perovskite interface.
• Reducing interface defects and residual lead iodide clusters.

Main Results:

• Achieved a photovoltaic conversion efficiency of 19.15% in hole transport layer-free carbon-based PSCs.
• Demonstrated significantly enhanced device stability.
• Improved ETL conductivity and charge extraction efficiency.
• Smoothed the perovskite film's bottom interface, enhancing physical contact with the ETL.

Conclusions:

• The ECM-TTPBr copassivation strategy offers a technically feasible pathway for industrializing high-efficiency and stable PSCs.
• Dual interface passivation effectively minimizes defects and enhances charge dynamics.
• This approach contributes to the development of next-generation perovskite solar cell technologies.