Solvent-Assisted Heterojunction Interface Passivation via DMSO Modification for High-Efficiency Sb₂Se₃ Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Semiconductor Physics

Background:

• Antimony selenide (Sb2Se3) is a promising photovoltaic absorber exceeding 10% power conversion efficiency.
• Performance is limited by defects in the space charge depletion region near heterojunction interfaces.
• Effective defect passivation is crucial for advancing Sb2Se3 solar cell technology.

Purpose of the Study:

• To introduce a solvent-assisted annealing strategy for passivating surface defects in Sb2Se3.
• To investigate the mechanism of defect mitigation using dimethyl sulfoxide (DMSO).
• To improve the heterojunction quality and power conversion efficiency of Sb2Se3 photovoltaics.

Main Methods:

• Solvent-assisted annealing using dimethyl sulfoxide (DMSO).
• Surface analysis to identify oxide removal and sulfur incorporation.
• Passivation of selenium vacancy defects (VSe2, VSe3) via sulfur incorporation.
• Theoretical calculations to understand DMSO chemisorption and Sb-Se lattice interaction.

Main Results:

• DMSO treatment effectively passivates surface defects by removing oxides and incorporating sulfur.
• Incorporated sulfur neutralizes surface states and passivates deep-level selenium vacancies.
• Theoretical calculations confirm strong Sb-S bonding, facilitating controlled surface etching.
• Achieved a champion power conversion efficiency of 10.48%, a 17% relative improvement over control devices (8.99%).

Conclusions:

• Solvent-assisted DMSO annealing is a simple and effective method for defect mitigation in Sb2Se3.
• The strategy significantly improves heterojunction quality and photovoltaic performance.
• This approach supports the practical application and development of Sb2Se3 photovoltaics.