Efficient and Stable Perovskite Solar Cells with a Superhydrophobic Two-Dimensional Capping Layer

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Two-dimensional (2D) perovskite layers are crucial for enhancing the stability of perovskite solar cells (PSCs).
• Traditional PSCs often face efficiency limitations despite passivation efforts.
• Defect passivation is key to achieving long-term operational stability in PSCs.

Purpose of the Study:

• To improve the efficiency and long-term stability of perovskite solar cells (PSCs).
• To investigate the use of a novel 2D perovskite passivation layer for defect mitigation.
• To explore the impact of a hydrophobic organic cation on PSC performance and durability.

Main Methods:

• Fabrication of 2D/3D structured PSCs using a hydrophobic organic cation, 2-[4-(trifluoromethyl)phenyl]ethanamine (CF3-PEA).
• Formation of a 2D (CF3-PEA)2PbI4 passivation layer on a 3D MAPbI3 perovskite.
• Characterization of charge recombination, carrier lifetime, charge generation, and transport properties.

Main Results:

• The 2D/3D structured PSCs exhibited reduced charge recombination and elongated carrier lifetimes.
• Significant efficiency enhancement from 17.9% (pristine) to 21.43% (2D/3D structured).
• Remarkable stability improvements: 83% efficiency retained after 600h at 80% RH/50°C and 87% under 1 sun illumination.

Conclusions:

• The hydrophobic 2D passivation layer effectively passivates defects in 3D perovskites, enhancing PSC performance.
• The developed 2D/3D PSCs demonstrate a promising balance of high efficiency and exceptional operational stability.
• This approach offers a viable strategy for creating highly stable and efficient MAPbI3-based perovskite solar cells.