Amino Pyridine Iodine as an Additive for Defect-Passivated Perovskite Solar Cells

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photovoltaics

Background:

• Defect passivation is crucial for reducing charge recombination in perovskites.
• Lewis acid/base functional groups neutralize trap states, limiting nonradiative recombination.
• Zwitterions offer simultaneous passivation of both anionic and cationic defects, unlike traditional molecules.

Purpose of the Study:

• To investigate the use of zwitterions organic halide salt 1-amino pyridine iodine (AmPyI) for perovskite defect passivation.
• To evaluate the impact of AmPyI on perovskite film quality, charge recombination, and device performance.

Main Methods:

• Utilized AmPyI as an additive for perovskite defect passivation.
• Analyzed defect passivation mechanisms via hydrogen bonding and ionic interactions.
• Characterized perovskite film morphology, crystallinity, and device performance.

Main Results:

• AmPyI passivates surface and grain boundary defects through hydrogen bonding.
• The iodide component of AmPyI binds uncoordinated Pb2+, improves film morphology, and enhances crystallinity.
• Achieved amplified perovskite grains (1.24 μm) and a power conversion efficiency of 23.80% with minimal hysteresis.

Conclusions:

• AmPyI is an effective zwitterionic passivator for perovskite solar cells.
• Simultaneous defect passivation by AmPyI leads to improved film quality and device performance.
• This approach offers a promising strategy for high-efficiency and stable perovskite photovoltaics.