Structural and Optical Characterization of Mechanochemically Synthesized CuSbS₂ Compounds

Area of Science:

• Materials Science
• Solid State Chemistry
• Photovoltaics

Background:

• Research on thin-film solar cells seeks earth-abundant alternatives to indium (In) and gallium (Ga).
• Chalcostibite (CuSbS2) is a promising, environmentally friendly material for photovoltaic applications.
• Developing cost-effective synthesis methods is crucial for widespread adoption.

Purpose of the Study:

• To synthesize single-phase chalcostibite (CuSbS2) using a short-duration mechanochemical method.
• To characterize the structural, particle size, and thermal properties of the synthesized material.
• To evaluate the suitability of mechanochemically synthesized CuSbS2 for photovoltaic absorber applications.

Main Methods:

• Mechanochemical synthesis from elemental powders (2-hour duration).
• X-ray diffraction (XRD) for phase purity and crystallite size analysis.
• Particle size analysis (median diameter determination).
• Thermogravimetry (TGA) and differential thermal analysis (DTA) for thermal stability.
• UV-VIS-NIR spectroscopy for optical band gap determination.

Main Results:

• Successful synthesis of single-phase orthorhombic chalcostibite (CuSbS2, space group Pnma).
• Crystallite size of 26 nm and median particle diameter between 2.93–3.10 μm.
• High thermal stability, with no phase change observed after heating at 350 °C for 24 h.
• Optical band gap determined to be 1.41 eV, suitable for solar absorber materials.

Conclusions:

• Mechanochemical synthesis is a viable and efficient route for producing CuSbS2.
• The synthesized CuSbS2 exhibits properties suitable for thin-film solar cell absorber layers.
• This method offers a cost-effective and environmentally friendly approach to photovoltaic material production.