Over 10% Efficient Sb₂(S,Se)₃ Solar Cells Enabled by CsI-Doping Strategy.

Area of Science:

• Materials Science
• Renewable Energy
• Semiconductor Physics

Background:

• Antimony selenosulfide (Sb2(S,Se)3) is a quasi-1D photovoltaic material with promising photoelectric properties.
• Its low-symmetry chain structure presents challenges for defect management and property enhancement via traditional doping.
• Improving the efficiency of Sb2(S,Se)3-based solar cells is crucial for advancing photovoltaic technologies.

Purpose of the Study:

• To develop a novel doping strategy for enhancing the performance of antimony selenosulfide solar cells.
• To investigate the effects of alkali halide doping on the structural and electronic properties of Sb2(S,Se)3.
• To achieve higher power conversion efficiencies in Sb2(S,Se)3 solar cells through optimized doping.

Main Methods:

• Utilizing alkali halide (cesium iodide, CsI) as a precursor in a hydrothermal reaction for doping Sb2(S,Se)3.
• Characterizing the doped Sb2(S,Se)3 material using techniques to analyze ion incorporation, morphology, and defect levels.
• Fabricating and evaluating the performance of CsI-doped Sb2(S,Se)3 solar cells under standard illumination conditions.

Main Results:

• Cesium (Cs) and Iodine (I) ions were successfully incorporated and coordinated with Sb and S/Se ions in the Sb2(S,Se)3 lattice.
• CsI-doped Sb2(S,Se)3 absorbers showed improved grain morphology and significantly reduced trap densities.
• The resulting solar cells exhibited favorable band alignment, suppressed charge recombination, and enhanced device performance.
• A power conversion efficiency of 10.05% was achieved for the CsI-doped Sb2(S,Se)3 solar cells.

Conclusions:

• Alkali halide doping, specifically using CsI, is an effective strategy to improve Sb2(S,Se)3 solar cell efficiency.
• The doping process enhances material quality by optimizing morphology and reducing defect-related recombination.
• This precursor-based doping approach offers a viable pathway for the development of high-performance antimony selenosulfide photovoltaic devices.