Effect of substrate temperature on the physical properties of SnS₂:Cu thin films deposited by spray pyrolysis

Abstract

The main impetus of the present study is to investigate thin films of tin disulfide that have been doped with copper impurities and prepared on glass substrates by using the spray pyrolysis technique. Also, the influence of the substrate temperature on the structural, optical, and electrical properties of these films are investigated. The thin films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical absorption (UV–vis) analyses. The XRD patterns clarify that the thin films possess polycrystalline structures, having a peak associated with the (001) plane of the SnS2 phase. The average crystalline grain sizes were estimated to be within the range 5.7–7.1 nm. The SEM images indicate that the grain size increases from 53 to 114 nm with an increment in the substrate temperature, resulting in an increasing–decreasing trend in the band gap of the thin films. However, the films’ resistance decreases from 92.5 to 0.174 Ω·cm as the substrate temperature increases from 400 to 450 °C. Also, their optical energy band gap depicts an increasing–decreasing trend with the estimated values of 2.81, 3.21, and 3.06 eV at 400, 425, and 450 °C, respectively. The thin films exhibit n-type conductivity.

Effect of substrate temperature on physical properties of Co doped SnS2 thin films deposited by ultrasonic spray pyrolysis

“…Therefore, high conductivity of the Co doped SnS 2 film is about 5.00 Ω −1 cm −1 obtained at 400 °C which is attributed to improved crystallization in accordance with XRD results. Same trend in the variation of electrical proprieties is reported on Cu doping [21] in SnS 2 deposited using spray pyrolysis technique at various substrate temperatures.…”

“…In fact, the growth of clusters was observed in all other samples caused by the effect of Cobalt in enhancing the surface topography of the films, because the addition of Cobalt atoms to the deposited solution with increasing the temperature led to their coalescence and hence the formation of larger grain sizes. This granular morphology was observed by Fadavieslam [21] for sprayed Cu doped SnS 2 films with variation of substrate temperature. The SEM images exhibited that the surface morphology of the Co doped SnS 2 films strongly dependent on the substrate temperature.…”

“…The obtained patterns were not identified peaks that characterized the other phases of tin sulfide and its combination or the metallic Sn and Co because the radius of the Sn 2+ ion is bigger than that of Co 2+ ion. Fadavieslam [21] and Yassin et al [22] have found the same peak (001) for SnS 2 films doped with different impurities (Cu, V, and W) elaborated by spray pyrolysis. Also, similar results were observed about the formation of SnS 2 phase in using other deposition techniques.…”