Direct synthesis of nanostructured silver antimony sulfide powders from metal xanthate precursors

Silver(I) ethylxanthate [AgS₂COEt] (1) and antimony(III) ethylxanthate [Sb(S₂COEt)₃] (2) have been synthesised, characterised and used as precursors for the preparation of AgSbS₂ powders and thin films using a solvent-free melt method and spin coating technique, respectively. The as-synthesized AgSbS₂ powders were characterized by powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. The crystalline AgSbS₂ powder was investigated using XRD, which shows that AgSbS₂ has cuboargyrite as the dominant phase, which was also confirmed by Raman spectroscopy. SEM was also used to study the morphology of the resulting material which is potentially nanostructured. EDX spectra gives a clear indication of the presence of silver (Ag), antimony (Sb) and sulfur (S) in material, suggesting that decomposition is clean and produces high quality AgSbS₂ crystalline powder, which is consistent with the XRD and Raman data. Electronic properties of AgSbS₂ thin films deposited by spin coating show a p-type conductivity with measured carrier mobility of 81 cm² V^-1 s^-1 and carrier concentration of 1.9 × 10¹⁵ cm^-3. The findings of this study reveal a new bottom-up route to these compounds, which have potential application as absorber layers in solar cells.