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  • Structural and Optical Characterization of Mechanochemically Synthesized CuSbS2† [Abstract]
    Publication . Esperto, Luís; Figueira, Isabel; Mascarenhas, João; Silva, Teresa; Correia, J.B.; Neves, Filipe
    ABSTRACT: The present work describes experimental studies related to the characterization of CuSbS2 directly synthesized after 2 h of mechanochemical synthesis (MCS) at 340 rpm, starting from mixtures of elemental powders. X-ray diffraction (XRD) and UV-VIS-NIR spectroscopy were carried out to analyze the crystal structure, degree of crystallinity, crystallite size and optical properties of the mechanochemically synthesized CuSbS2 powders. Rietveld refinement was carried out using Diffrac. TOPAS (Bruker AXS). Thermal stability of the synthesized materials was evaluated by the vacuum thermal heat treatment of the mechanochemically synthesized CuSbS2 powders at 350 °C for 24 h. Furthermore, the CuSbS2 powders were also analyzed by field-emission scanning electron microscopy (FE-SEM), laser diffraction, and differential thermal analysis.
  • Structural and optical characterization of mechanochemically synthesized CuSbS2 compounds
    Publication . Esperto, Luís; Figueira, Isabel; Mascarenhas, João; Silva, Teresa; Correia, J.B.; Neves, Filipe
    ABSTRACT: One of the areas of research on materials for thin-film solar cells focuses on replacing In and Ga with more earth-abundant elements. In that respect, chalcostibite (CuSbS2) is being considered as a promising environmentally friendly and cost-effective photovoltaic absorber material. In the present work, single CuSbS2 phase was synthesized directly by a short-duration (2 h) mechanochemical-synthesis step starting from mixtures of elemental powders. X-ray diffraction analysis of the synthesized CuSbS2 powders revealed a good agreement with the orthorhombic chalcostibite phase, space group Pnma, and a crystallite size of 26 nm. Particle-size characterization revealed a multimodal distribution with a median diameter ranging from of 2.93 mu m to 3.10 mu m. The thermal stability of the synthesized CuSbS2 powders was evaluated by thermogravimetry and differential thermal analysis. No phase change was observed by heat-treating the mechanochemically synthesized powders at 350 degrees C for 24 h. By UV-VIS-NIR spectroscopy the optical band gap was determined to be 1.41 eV, suggesting that the mechanochemically synthesized CuSbS2 can be considered suitable to be used as absorber materials. Overall, the results show that the mechanochemical process is a viable route for the synthesis of materials for photovoltaic applications.