Suppressing Multi-Dimensional Defects in Cs_0.05FA_0.95PbI₃ Single Crystals Enables Efficient and Stable Back-Contacted...

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Back-contacted perovskite solar cells (PSCs) offer cost and stability benefits.
• Current PSC efficiencies are limited by defect-induced recombination and poor carrier diffusion in thin crystals.

Purpose of the Study:

• To overcome efficiency limitations in back-contacted PSCs.
• To develop a multi-dimensional defect suppression strategy for perovskite crystals.

Main Methods:

• Incorporated N-methylformamidinium (MFA+) into Cs0.05FA0.95PbI3 crystals.
• Investigated the impact of MFA+ on crystal quality, defect suppression, and carrier transport.

Main Results:

• MFA+ incorporation suppressed point, line, and plane defects, including iodide vacancies, microstrain, dislocations, and surface wrinkles.
• Achieved high-quality crystals with extended electron diffusion lengths (∼400 µm).
• Demonstrated a record 17.35% efficiency for back-contacted PSCs.

Conclusions:

• Multi-dimensional defect suppression is crucial for enhancing carrier transport in PSCs.
• The developed strategy significantly advances the efficiency and stability of back-contacted PSCs.
• This approach provides valuable insights for future high-performance PSC development.