Combinatorial synthesis of tin antimony sulfide thin films for solar cell application

Tin antimony sulfide (SnSb₂S₄) has gained tremendous research attention due to its low cost, environment-friendly, and abundant photovoltaic material in recent years. However, the high resistivity and low carrier density have limited its scope of applications. In this work, thin film of tin antimony sulfide (TAS) was deposited combinatorially using thermal evaporation techniques. The combinatorial film was synthesized by using baffles inside the vacuum chamber to control the flume. The as deposited combinatorial thin film was annealed inside argon gas in a glass ampule at 175°C. The elemental, structural, and optical characterizations of the films deposited with various elemental compositions are reported. To comprehend the study, ten different points of elemental composition were selected. The XRD analysis of the obtained annealed film revealed its SnSb₂S₄ phase. From our further measurements, it is found that the film is highly absorbent. The results of transmittance are found to be decreased with increasing content of antimony and no transmittance is absorbed below the visible range. Although the film shows good photoconductivity, few of the points in the thin film are found highly photoactive. The p-type semi-conductivity nature of the film was found for all points by the hotpoint probe technique.