Multifunctional SnO₂/Perovskite Interface Engineering for Efficient Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) show commercial promise but are hindered by material defects and instability.
• Surface defects and ion migration in PSCs limit their power conversion efficiency and operational lifetime.
• Tin dioxide (SnO₂) is a common electron transport material in PSCs, but its surface properties can impact performance.

Purpose of the Study:

• To develop a surface treatment strategy for SnO₂ to improve PSC efficiency and stability.
• To investigate the role of aluminum chloride in passivating the SnO₂/perovskite interface.
• To achieve high-performance and durable single-junction n-i-p PSCs.

Main Methods:

• Treatment of the SnO₂ surface with aluminum chloride to remove hydroxyl groups and potassium ions.
• Formation of an ultra-thin aluminum oxide passivation layer at the SnO₂/perovskite interface.
• Characterization of the modified interface and evaluation of photovoltaic performance and device stability.

Main Results:

• The aluminum chloride treatment effectively passivated the SnO₂ surface, reducing deprotonation and recombination.
• Achieved a certified power conversion efficiency of 26.29% in single-junction n-i-p PSCs, the highest reported for SnO₂-based devices.
• Demonstrated enhanced stability, retaining 94% efficiency after 10,044 hours and a T₈₀ lifetime exceeding 500 hours under illumination.

Conclusions:

• Surface engineering with aluminum chloride is a viable strategy to enhance PSC performance and longevity.
• The aluminum oxide passivation layer effectively mitigates charge carrier recombination and improves device efficiency.
• This approach offers critical insights for advancing the chemical and physical interface properties of PSCs for next-generation solar energy.