F-Type Pseudo-Halide Anions for High-Efficiency and Stable Wide-Band-Gap Inverted Perovskite Solar Cells with Fill...

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Wide-band-gap (WBG) perovskite films are crucial for high-performance tandem solar cells.
• Improving WBG perovskite film quality is essential for advancing tandem solar cell technology.

Purpose of the Study:

• To enhance the quality and performance of WBG perovskite films using F-type pseudo-halogen additives.
• To investigate the impact of these additives on perovskite film properties and device efficiency.

Main Methods:

• Incorporation of F-type pseudo-halogen additives (PF6- or BF4-) into perovskite precursors.
• Characterization of perovskite film properties, including grain size, crystal quality, and defect density.
• Fabrication and testing of inverted 1.67 eV perovskite devices and perovskite/silicon tandem solar cells.

Main Results:

• Perovskite films with F-type additives exhibited larger grain size, higher crystal quality, and lower defect density.
• Additives led to lattice expansion, reduced stress distortion, suppressed carrier recombination, and inhibited phase separation.
• Achieved over 20% power conversion efficiency (PCE) for inverted perovskite devices with 84.02% fill factor and improved stability.
• Reached 27.35% (PF6-) and 27.11% (BF4-) PCE in four-terminal perovskite/silicon tandem solar cells.

Conclusions:

• F-type pseudo-halogen additives significantly improve WBG perovskite film quality and device performance.
• The strategy offers a promising pathway for developing highly efficient and stable perovskite-based solar cells and tandem devices.
• This research provides valuable insights for optimizing WBG perovskite solar cell development.