Crown Ether-Modified 1D/3D Heterojunction for Efficient and Stable Carbon-Based CsPbI₃ Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Interface engineering is crucial for perovskite solar cell (PSC) stability and performance.
• Single interface modification steps often yield limited improvements.
• Synergistic effects from multi-step engineering are needed for optimal device outcomes.

Purpose of the Study:

• To develop and investigate a two-step interface engineering strategy for CsPbI3 perovskite solar cells.
• To enhance the efficiency and long-term stability of perovskite solar cells through novel surface modifications.
• To address unpassivated surface defects and interfacial recombination in PSCs.

Main Methods:

• Fabrication of CsPbI3 perovskite solar cells.
• Two-step interface engineering: initial modification with choline iodide (ChI) to form a 1D ChPbI3/3D CsPbI3 heterojunction, followed by crown ether surface treatment.
• Characterization of device performance and stability under various stress conditions (moisture, heat, light).

Main Results:

• The two-step interface engineering strategy significantly passivated surface defects.
• Resultant carbon-electrode-based CsPbI3 PSCs (C-PSCs) achieved a champion power conversion efficiency of 18.78%.
• Enhanced device stability against moisture, heat, and light stress was observed due to improved hydrophobicity and suppressed ion migration.

Conclusions:

• The developed two-step interface engineering approach effectively suppresses interfacial recombination and enhances PSC performance.
• Crown ether plays a vital role in further defect passivation and improving device stability.
• This strategy offers a promising pathway for developing highly efficient and stable perovskite solar cells.