Low-Cost Antimony Selenosulfide with Tunable Bandgap for Highly Efficient Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Antimony selenosulfide (Sb₂ (S,Se)₃ ) solar cells offer potential for efficient energy conversion.
• Previous methods using selenourea faced challenges in bandgap tuning and high cost.
• Optimizing Sb₂ (S,Se)₃ for ideal bandgaps (1.3-1.4 eV) and reducing fabrication expenses are critical for commercial viability.

Purpose of the Study:

• To develop a straightforward, one-step hydrothermal method for preparing high-quality Sb₂ (S,Se)₃ films.
• To utilize a novel, cost-effective selenium precursor, sodium selenosulfate.
• To achieve tunable bandgaps and high power conversion efficiencies in Sb₂ (S,Se)₃ solar cells.

Main Methods:

• A one-step hydrothermal synthesis was employed to create Sb₂ (S,Se)₃ absorber layers.
• The Se/(Se+S) ratio in the precursor solution was tuned to control film properties.
• Solar cell devices were fabricated and characterized for efficiency, bandgap, and stability.

Main Results:

• High-quality Sb₂ (S,Se)₃ films with tunable bandgaps ranging from 1.31 to 1.71 eV were successfully prepared.
• The optimized solar cells achieved a power conversion efficiency of 10.05% with a current density of 26.01 mA cm^-2 at a 1.35 eV bandgap.
• Production costs were reduced by over 80% compared to selenourea-based methods, and devices maintained over 93% efficiency after 30 days of atmospheric exposure.

Conclusions:

• The novel sodium selenosulfate precursor enables facile and cost-effective fabrication of high-performance Sb₂ (S,Se)₃ solar cells.
• The developed method allows for precise bandgap tuning, crucial for optimizing photovoltaic efficiency.
• This work presents a promising pathway for low-cost, high-efficiency, and stable chalcogenide-based photovoltaic devices.