Surface Reconstruction Drives Highly Efficient Carrier Management in Antimony Selenosulfide Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Semiconductor Devices

Background:

• Antimony selenosulfide (Sb₂(S,Se)₃) solar cells show photovoltaic potential.
• Chemical bath deposition (CBD) processed Sb₂(S,Se)₃ solar cells are limited by carrier loss and efficiencies below 10%.

Purpose of the Study:

• To improve the performance of CBD-processed Sb₂(S,Se)₃ solar cells.
• To address carrier loss bottlenecks in Sb₂(S,Se)₃ solar cells.

Main Methods:

• A surface reconstruction (SR) strategy involving depositing an amorphous Sb₂S₃ layer followed by postannealing.
• Promoting anion interdiffusion to create a gradient bandgap structure.

Main Results:

• Reduced carrier transport loss from 11.06% to 8.5%.
• Achieved a champion efficiency of 10.02%, the highest for CBD-processed Sb₂(S,Se)₃ solar cells.
• Enhanced bulk carrier transport and improved Sb₂(S,Se)₃/hole transport layer interface characteristics.

Conclusions:

• Surface reconstruction is an effective post-treatment strategy for Sb₂(S,Se)₃ solar cells.
• The developed method paves the way for high-performance optoelectronic devices.
• Gradient bandgap structures are beneficial for carrier transport in photovoltaic devices.