Bidirectional Chemo-Mechanical Interface Stabilization in Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face challenges with interface instability, leading to degradation.
• Lateral chemical aggregation and vertical delamination at interfaces hinder long-term performance.
• Existing methods lack a holistic approach to address these dual degradation pathways.

Purpose of the Study:

• To introduce a molecular-level stabilization strategy for the perovskite/C60 interface in PSCs.
• To mitigate concurrent chemical aggregation and mechanical delamination at critical interfaces.
• To enhance the operational stability and efficiency of perovskite solar cells.

Main Methods:

• Incorporation of an ultrathin 1,3,6,8-pyrenetetrasulfonic tetrasodium salt (PTS) interfacial layer.
• Utilizing PTS's sulfonate groups for perovskite anchoring and pyrene cores for π-π interactions with C60.
• Implementing a bidirectional chemo-mechanical interface stabilization (BCIS) mechanism.

Main Results:

• Achieved power conversion efficiencies (PCEs) up to 26.53% in PSCs.
• Demonstrated high operational stability: 96% PCE retention after 1,000 hours and 91% after 300 thermal cycles.
• Successfully scaled PTS treatment for large-area (818 cm²) perovskite solar modules (PSMs) with PCEs over 20% under industrial conditions.

Conclusions:

• Bidirectional interface engineering using PTS is a highly effective strategy for stabilizing PSCs.
• The BCIS mechanism significantly improves device longevity and performance.
• This approach paves the way for commercially viable perovskite photovoltaics.