Interfacial stabilization for inverted perovskite solar cells with long-term stability

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) suffer from performance degradation caused by ion migration and electrode corrosion.
• Existing charge transport layers in PSCs are susceptible to degradation, limiting device operational lifetime.
• Interfacial instability is a primary bottleneck for the commercial viability of PSC technology.

Purpose of the Study:

• To develop an interfacial management strategy to improve the stability and efficiency of perovskite solar cells.
• To investigate the role of a boron chloride subphthalocyanine (Cl6SubPc)/fullerene electron-transport layer in passivating defects and suppressing ion migration.
• To evaluate the long-term operational stability of the modified perovskite solar cells under various stress conditions.

Main Methods:

• Fabrication of inverted perovskite solar cells incorporating a Cl6SubPc/fullerene electron-transport layer.
• Characterization of interfacial properties using techniques including electron energy loss spectroscopy with visual element mapping.
• Assessment of device performance and stability under damp heat stress, elevated temperature, illumination, and outdoor testing (ISOS-O-1).

Main Results:

• The Cl6SubPc interface effectively passivates perovskite defects and suppresses halide diffusion.
• Achieved a certified power conversion efficiency of 21.3% (22.0% initial) for the inverted PSCs.
• Demonstrated remarkable operational stability: T80 of 816 h under damp heat, 98% retention after 2000 h at 80°C, 90% after 2034 h illumination, and 95% after 1272 h outdoor testing.

Conclusions:

• The interfacial management strategy using Cl6SubPc significantly enhances the stability and performance of perovskite solar cells.
• The developed electron-transport layer effectively mitigates ion migration and electrode corrosion, crucial for long-term device operation.
• This approach represents a promising advancement towards the commercialization of stable and efficient perovskite solar technology.