Dual-Interface Modulation with Covalent Organic Framework Enables Efficient and Durable Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Dual-interface modulation is critical for high performance in lead halide perovskite solar cells (PSCs).
• Optimizing both buried and top surfaces is key to device efficiency and stability.

Purpose of the Study:

• To investigate the use of functional covalent organic frameworks (COFs), specifically HS-COFs, for dual-interface modulation in PSCs.
• To understand the intrinsic mechanisms by which HS-COFs optimize perovskite solar cell performance.

Main Methods:

• Application of HS-COFs as a buried layer to enhance UV resistance and reduce tensile strain.
• Utilization of HS-COFs on the top surface for defect passivation and suppression of non-radiative recombination.
• Characterization of perovskite film crystallization and growth with HS-COF modification.

Main Results:

• The buried HS-COFs layer improved perovskite crystal growth order and device stability.
• The top HS-COFs layer passivated surface defects and reduced recombination.
• Champion efficiencies of 24.26% (0.0725 cm²) and 21.30% (1 cm²) were achieved.
• Devices retained 88% and 84% efficiency after 2000h aging under ambient and heated nitrogen conditions, respectively.

Conclusions:

• HS-COFs effectively modulate dual interfaces in PSCs, enhancing both efficiency and stability.
• The synergistic effects of dual-interface modification with HS-COFs offer a promising strategy for advanced perovskite solar cells.