Dual-functional Interface Engineering with Picolinamide for Improved MAPbI_3-xCl_x Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face challenges like high defect density and energy-level misalignment.
• These issues cause nonradiative recombination and limit charge extraction efficiency in MAPbI_3-xCl_x PSCs.

Purpose of the Study:

• To investigate picolinamide (PA) as an interfacial modifier for MAPbI_3-xCl_x perovskite films.
• To enhance the properties and photovoltaic performance of perovskite solar cells using PA.

Main Methods:

• Introduced picolinamide (PA) as an ultrathin interlayer in inverted PSCs.
• Utilized PA's pyridine nitrogen and amide groups to passivate defects and optimize energy-level alignment.
• Assessed film hydrophobicity, ion migration, and moisture penetration.

Main Results:

• PA modification led to a champion power conversion efficiency (PCE) of 19.35%, a 23.01% improvement over control devices.
• Enhanced film hydrophobicity, reducing ion migration and moisture ingress.
• Unencapsulated devices retained over 80% of initial PCE after 180 days (N2) and 360 hours (ambient).

Conclusions:

• Picolinamide is a promising interfacial modifier for perovskite solar cells.
• PA effectively passivates defects, optimizes energy levels, and enhances device stability.
• This strategy offers a pathway to highly efficient and durable perovskite photovoltaics.