Abstract
? 2022 Elsevier B.V.In order to elaborate stoichiometric CuSbS2 and Cu12Sb4S13 (CAS) thin films by co-electrodeposition on FTO substrates, the copper concentration was varied between 0.015 M and 0.030 M at ? 0.98 mV co-electrodeposition potential (vs. saturated calomel electrode (SCE)). After a sulfurization step in a quartz tube at 410 °C under an argon flow for 45 min, the samples formed are analyzed by different techniques: The XRD technique has shown the existence of characteristic peaks of the CuSbS2 phase at 28.53, 28.79, 29.73 and 29.99° clearly for the 0.015 M concentration, but this XRD spectrum has shifted to that of Cu12Sb4S13 phase when the copper concentration increases to 0.030 M. Likewise the Raman spectroscopy has indicated the principal peak of CuSbS2 located at 337 cm?1 on the spectrum of the 0.015 M concentration, but this peak have disappeared for the 0.030 M concentration and was replaced by a new principal peak of Cu12Sb4S13 at 317 cm?1. This effect was confirmed by the UV-Visible spectrophotometry technique which shows an increase of optical gap from 1.46 eV (CuSbS2) to 1.81 eV (Cu12Sb4S13) when the copper concentration passes from 0.015 M to 0.030 M. The morphological study and EDS analysis have proved that the layers CuSbS2 and Cu12Sb4S13 were elaborated with good stoichiometry.
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Elsevier