Revealing composition and structure dependent deep-level defect in antimony trisulfide photovoltaics

Area of Science:

• Materials Science
• Solid-State Physics
• Photovoltaics

Background:

• Antimony trisulfide (Sb2S3) is an emerging light-harvesting material known for its stability and elemental abundance.
• Theoretical studies suggest complex defect properties in Sb2S3 due to its quasi-one-dimensional symmetry.
• Experimental verification of these defect properties has been lacking.

Purpose of the Study:

• To experimentally investigate the deep-level defect properties in Sb2S3.
• To understand the influence of defects on carrier lifetime in Sb2S3.
• To provide insights for enhancing the efficiency of Sb2S3-based solar cells.

Main Methods:

• Optical deep-level transient spectroscopy (ODLTS) was employed to study Sb2S3.
• Defect characterization was performed based on varying Sb2S3 compositions.
• Carrier lifetime was analyzed in relation to specific defect types, particularly Sb-interstitial (Sbi).

Main Results:

• Maximum of three distinct deep-level defects were identified in Sb2S3, with their presence dependent on material composition.
• The Sb-interstitial (Sbi) defect was found to have a minimal impact on carrier lifetime.
• The quasi-one-dimensional crystal structure of Sb2S3 demonstrates a high tolerance for accommodating impurities.

Conclusions:

• This research provides the first experimental evidence of deep-level defects in Sb2S3.
• The findings highlight the robustness of the Sb2S3 crystal structure against certain impurities.
• Understanding these defect properties offers a pathway for optimizing Sb2S3 solar cell performance.