2D Ti₃C₂-MXene Serving as Intermediate Layer between Absorber and Back Contact for Efficient CZTSSe Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) is a promising material for inorganic thin-film solar cells.
• The CZTSSe/Mo back interface is critical for hole extraction and overall device performance.
• Reactions at the CZTSSe/Mo interface during selenization cause performance losses.

Purpose of the Study:

• To optimize the CZTSSe/Mo back interface using a 2D Ti3C2-MXene intermediate layer.
• To suppress detrimental reactions between CZTSSe and Mo during fabrication.
• To enhance the performance of CZTSSe-based solar cells.

Main Methods:

• Introduction of a 2D Ti3C2-MXene layer between CZTSSe and Mo.
• Fabrication of CZTSSe thin-film solar cells with the MXene intermediate layer.
• Characterization of the interface and device performance.

Main Results:

• The 2D Ti3C2-MXene layer effectively suppressed the reaction between CZTSSe and Mo.
• The thickness of the Mo(S,Se)2 layer was significantly reduced.
• Interface recombination at the CZTSSe/Mo back interface was decreased.
• Power conversion efficiency of the champion device increased from 10.89% to 13.14%.

Conclusions:

• 2D Ti3C2-MXene is a promising intermediate layer for efficient CZTSSe solar cells.
• The study provides insights into optimizing the back interface of CZTSSe solar cells.
• This approach can lead to improved performance in thin-film solar cell technology.