The Residual PbI₂ Paradox in Perovskite Solar Cells: Harnessing Excess Phase for Synergistic Performance-Stability...

Area of Science:

• Materials Science
• Renewable Energy Technologies
• Photovoltaics

Background:

• Residual/excess lead iodide (PbI2) is crucial for high-efficiency perovskite solar cells (PSCs).
• However, the chemical activity of PbI2 presents significant challenges to device stability.
• Balancing efficiency and long-term operational stability is a key obstacle in perovskite photovoltaic development.

Purpose of the Study:

• To systematically analyze the mechanistic role of residual/excess PbI2 in PSCs.
• To elucidate the impact of PbI2 on both device efficiency and operational stability.
• To summarize recent strategies for regulating PbI2 to enhance PSC performance and longevity.

Main Methods:

• Literature review and systematic analysis of existing research on PbI2 in PSCs.
• Examination of the impact of PbI2 on perovskite film formation and device characteristics.
• Categorization and summary of current methods for controlling PbI2.

Main Results:

• Residual/excess PbI2 significantly influences PSC efficiency and stability mechanisms.
• Strategies for managing PbI2 include controlling its distribution, crystallization kinetics, and elimination.
• Effective PbI2 regulation is essential for achieving optimal device performance without compromising stability.

Conclusions:

• Understanding and controlling residual/excess PbI2 is critical for advancing perovskite solar cell technology.
• The reviewed strategies offer a roadmap for designing more stable and efficient PSCs.
• This work provides guidance for future research in high-performance, long-term stable perovskite photovoltaics.