Highly efficient and stable perovskite solar cells enabled by low-dimensional perovskitoids

Area of Science:

• Materials Science
• Photovoltaics
• Nanotechnology

Background:

• Defects at surfaces and grain boundaries in perovskite absorbers cause nonradiative recombination and degradation in perovskite solar cells (PSCs).
• These defects significantly limit the efficiency and long-term stability of PSCs.

Purpose of the Study:

• To improve the performance and stability of PSCs by addressing surface defects.
• To investigate the passivation effect of low-dimensional (LD) perovskitoids on three-dimensional (3D) perovskite absorbers.

Main Methods:

• Capping the photoactive layer of PSCs with low-dimensional (LD) perovskitoids (0D and 1D).
• Characterization of the 3D/LD perovskitoid interface for passivation mechanisms.
• Performance testing and stability assessment of the modified PSCs under operational conditions.

Main Results:

• Effective passivation of undercoordinated Pb ions and metallic Pb at the 3D perovskite surface via Pb-I bonding at the 3D/LD interface.
• Enhanced device stability and hydrophobicity due to the protective LD perovskitoid capping layer.
• Achieved a certified power conversion efficiency of 24.18% for the PSCs.
• Unencapsulated devices retained 90% of initial efficiency after 800 hours of continuous illumination.

Conclusions:

• LD perovskitoid capping is a viable strategy to mitigate defects and enhance PSC performance.
• The 3D/LD interface plays a crucial role in defect passivation and stability.
• This approach offers a promising route towards highly efficient and stable perovskite solar cells.