Inhibiting Buried Mechanical Failure via Vapor-Induced Chemical Reconstruction for Durable Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Tin dioxide (SnO2) is a key electron transport layer (ETL) in high-efficiency perovskite solar cells (PSCs).
• Surface reactivity of SnO2 can lead to degradation, causing cracks and voids at the buried interface.
• These defects hinder charge extraction and reduce device performance under operational stress.

Purpose of the Study:

• To investigate the degradation mechanism of SnO2 ETL in PSCs.
• To develop a surface modification strategy for enhancing SnO2 stability.
• To improve the efficiency and operational longevity of perovskite solar cells.

Main Methods:

• Chemical degradation pathway analysis of SnO2 surfaces.
• Ethanol vapor-induced reconstruction (EVR) for surface modification.
• Fabrication and characterization of n-i-p perovskite solar cells with EVR-treated SnO2.

Main Results:

• Identified reactive surface species on SnO2 as a cause of interface failure.
• EVR strategy converts hydroxyl groups to a stable acetate passivation layer, addressing oxygen vacancies.
• EVR treatment suppressed crack and void formation, enhancing interface stability.
• Optimized EVR n-i-p PSCs achieved a 26.19% power conversion efficiency (PCE).

Conclusions:

• Surface reconstruction via EVR is crucial for robust buried interfaces in PSCs.
• The acetate passivation layer effectively enhances chemical stability and suppresses degradation.
• EVR strategy significantly improves device efficiency, stabilized power output, and long-term operational stability.