Stabilization of FAPbI₃ with Multifunctional Alkali-Functionalized Polymer

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Defects at interfaces and grain boundaries (GBs) in perovskite films degrade photovoltaic performance and stability.
• Effective strategies include manipulating crystallization and using molecular passivators to mitigate these issues.

Purpose of the Study:

• To develop a novel strategy for manipulating FAPbI3 perovskite crystallization.
• To passivate defects and enhance the performance and stability of perovskite solar cells.

Main Methods:

• Incorporating alkali-functionalized polymers into the antisolvent solution during perovskite film formation.
• Utilizing the synergistic effects of alkali cations and poly(acrylic acid) anions for defect passivation.
• Investigating the interaction between C=O bonds and Pb2+ for reduced lead leakage.

Main Results:

• Rubidium (Rb)-functionalized poly(acrylic acid) significantly improved the power conversion efficiency of FAPbI3 perovskite solar cells to nearly 25%.
• The strategy effectively passivated surface and GB defects in perovskite films.
• Reduced risk of lead ion (Pb2+) leakage was observed due to strong C=O bond interactions.
• Unencapsulated devices demonstrated enhanced operational stability, retaining 80% efficiency after 500 hours.

Conclusions:

• Alkali-functionalized polymers offer a promising approach to enhance perovskite solar cell performance and stability.
• This method effectively addresses critical defect issues and improves device longevity.
• The findings contribute to the advancement of efficient and stable perovskite photovoltaic technology.