Insight into the Role of Rb Doping for Highly Efficient Kesterite Cu₂ZnSn(S,Se)₄ Solar Cells

Area of Science:

• Materials Science
• Renewable Energy

Background:

• Copper-related defects limit the efficiency of Copper Zinc Tin Sulfide Selenide (CZTSSe) solar cells.
• Alkali metal doping is a promising strategy to mitigate these defects.

Purpose of the Study:

• To investigate the effect of Rubidium (Rb) doping on CZTSSe thin films.
• To enhance the efficiency of CZTSSe solar cells by suppressing copper-related defects.

Main Methods:

• CZTSSe thin films were synthesized using the sol-gel technique.
• Rubidium (Rb) was introduced as a dopant into the CZTSSe lattice.
• Scanning Electron Microscopy (SEM) was used to analyze film morphology.

Main Results:

• Rb atoms successfully incorporated into the CZTSSe lattice, substituting Copper (Cu) atoms.
• Moderate Rb doping (2%) enhanced grain growth, resulting in denser films with fewer defects.
• Rb doping effectively suppressed the formation of Cu-related defects and improved electrical properties.

Conclusions:

• Rubidium doping is a viable method to reduce copper-related defects in CZTSSe.
• Optimized Rb doping (2%) leads to a significant increase in solar cell efficiency.
• This research provides insights into alkali metal doping for improving CZTSSe solar cell performance.