Highly efficient p-i-n perovskite solar cells that endure temperature variations.

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Daily temperature fluctuations cause phase transitions and lattice strains in halide perovskites, compromising their stability in solar cell applications.
• Developing stable perovskite solar cells is crucial for advancing renewable energy technologies.

Purpose of the Study:

• To enhance the operational stability and performance of perovskite solar cells.
• To investigate the role of β-poly(1,1-difluoroethylene) in stabilizing the perovskite black phase and controlling film crystallization.

Main Methods:

• Utilized the ordered dipolar structure of β-poly(1,1-difluoroethylene) to influence perovskite film crystallization and energy level alignment.
• Fabricated and tested p-i-n perovskite solar cells incorporating the stabilizing polymer.
• Conducted long-term stability tests under continuous 1-sun maximum power point tracking at elevated temperatures (25°C and 75°C) and rapid thermal cycling (-60°C to +80°C).

Main Results:

• Achieved record power conversion efficiencies of 24.6% for 18 mm² cells and 23.1% for 1 cm² cells.
• Demonstrated remarkable operational stability, retaining 96% and 88% of initial efficiency after 1000 hours at 25°C and 75°C, respectively.
• Observed no performance degradation under rapid thermal cycling, highlighting the material's robustness.

Conclusions:

• The ordered dipolar structure of β-poly(1,1-difluoroethylene) effectively stabilizes the perovskite black phase, mitigating issues from temperature variations.
• This stabilization strategy significantly improves both the power conversion efficiency and long-term operational stability of perovskite solar cells.
• The findings present a promising approach for developing durable and high-performance perovskite solar cells for practical applications.