Perovskite/CIGS Tandem Solar Cells with over 1000 h Operational Stability through Interconnection Stress Relief.

Area of Science:

• Materials Science
• Renewable Energy Technologies
• Photovoltaics

Background:

• Perovskite/CIGS thin-film tandem solar cells are promising for lightweight, cost-effective photovoltaics.
• Long-term operational stability remains a key challenge for their practical application.

Purpose of the Study:

• Investigate the impact of CIGS substrate surface morphology on perovskite film stress and stability.
• Enhance the photothermal tolerance and operational lifetime of perovskite/CIGS tandem solar cells.

Main Methods:

• Deposited perovskite films on both smoothed and rough (corrugated) CIGS substrates.
• Analyzed the effects of substrate morphology on perovskite film stress, chemical structure, and defect properties.
• Fabricated and tested monolithic perovskite/CIGS tandem solar devices under various stress conditions.

Main Results:

• Perovskite films on smoothed CIGS exhibited tensile stress, leading to instability.
• Rough CIGS substrates alleviated tensile stress, enhancing perovskite film properties.
• Achieved a certified stabilized efficiency over 28% with an extended T80 lifetime of 1123 hours.
• Demonstrated improved stability at 60°C and during thermal cycling tests.

Conclusions:

• Substrate surface engineering is crucial for enhancing the long-term stability of perovskite/CIGS tandem solar cells.
• Corrugated CIGS surfaces effectively mitigate detrimental tensile stresses in perovskite films.
• Optimized interconnection contact design is essential for robust perovskite-based photovoltaic devices.