Pyridine-Anchored Small Molecule Interlayer Enables Defect Passivation and Enhanced Carrier Transport for Perovskite...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) are promising for next-generation photovoltaics.
• Interface engineering between perovskite and hole transport layers (HTLs) is critical for device performance.
• Existing interfacial materials face challenges in defect passivation and stability.

Purpose of the Study:

• To design and investigate novel interfacial materials for PSCs.
• To understand the relationship between molecular structure, spatial conformation, and passivation effects.
• To improve the efficiency and stability of perovskite solar cells.

Main Methods:

• Designed two interfacial materials, MN-CZ and CN-CZ, by regulating group substitution sites.
• Investigated the spatial conformation and passivation effects of the designed molecules.
• Fabricated and characterized perovskite solar cells using the novel interfacial materials.

Main Results:

• CN-CZ molecules demonstrated a stronger "vector addition" effect, leading to larger molecular dipoles.
• Enhanced defect passivation and energy level regulation were observed with CN-CZ.
• CN-CZ-based PSCs achieved a high efficiency of 23.8%, surpassing the reference device.
• Significantly improved humidity and thermal stability for unencapsulated devices.

Conclusions:

• Molecular design of interfacial materials is key to optimizing PSC performance.
• CN-CZ represents a highly effective interfacial material for high-efficiency and stable perovskite solar cells.
• The findings pave the way for more robust and efficient perovskite solar cell technologies.