Managing Interface Defects via Mixed-Salt Passivation toward Efficient and Stable Perovskite Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Surface Chemistry

Background:

• Perovskite solar cells (PSCs) face efficiency and stability limitations due to surface defects like iodine vacancies and uncoordinated Pb0.
• These defects act as deep-level traps, hindering charge carrier dynamics and device longevity.

Purpose of the Study:

• To develop a novel surface functionalization strategy for PSCs.
• To mitigate detrimental effects of surface defects on device performance and stability.

Main Methods:

• Surface functionalization of perovskite layers using trimethylsulfoxonium iodide (TMSI).
• Investigating the impact of TMSI on defect formation energy and Pb0 defect inhibition.
• Analyzing the effect of TMSI on iodine vacancies.

Main Results:

• TMSI treatment enhances defect formation energy and suppresses Pb0 defects.
• TMSI effectively passivates iodine vacancies on the perovskite surface.
• Optimized devices exhibit improved charge dynamics and reduced energy losses.
• Achieved a champion power conversion efficiency of 24.03%.

Conclusions:

• TMSI is a promising surface modifier for perovskite solar cells.
• Effective management of interface defects is crucial for high-efficiency and stable PSCs.
• This approach offers a viable strategy for advancing perovskite solar technology.