An Inert Fluoride Interlayer Enabling Efficient and Stable Inverted Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Device Physics

Background:

• Commercialization of perovskite solar cells (PSCs) is limited by interfacial instability.
• Organic passivation layers degrade, accelerating device performance decay.

Purpose of the Study:

• To develop a stabilization strategy for inverted PSCs.
• To enhance the operational stability and efficiency of PSC devices.

Main Methods:

• Introduction of an ultrathin interlayer of inert alkaline-earth metal fluorides.
• Placement of the interlayer between the passivation layer and the electron-transport layer.
• Characterization of interfacial properties and device performance.

Main Results:

• The interlayer homogenizes interfacial contact-potential distribution without hindering transport properties.
• The inert interlayer preserves interfacial integrity and prevents detrimental reactions.
• Devices achieved power-conversion efficiencies exceeding 26% and retained over 91% efficiency after 1000 hours.

Conclusions:

• The ultrathin inert-interlayer approach provides a scalable pathway for highly efficient and durable inverted PSCs.
• This strategy effectively addresses interfacial degradation issues in PSCs.
• The CaF2 interlayer significantly improves operational stability.