Sulfurization growth of SnS films and fabrication of ZnO/SnS heterojunction for solar cells

Polycrystalline tin sulfide (SnS) films were grown by sulfurization. The SnS film sulfurized at 400 °C comprises densely packed 300-800-nm-diameter columnar grains, and the surface of the SnS film revealed that no crack and pinhole were observed, which are appropriate for use in the photoabsorption layers of SnS solar cells. Using appropriate SnS film, SnS solar cells with an n-CdS/p-SnS and with an n-ZnO/p-SnS structure were fabricated on Mo-coated SLG substrates. The conversion efficiency is improved just due to the using of the ZnO as an n-type layer instead of CdS. These results represent the first step toward realizing high-performance solar cells using a SnS film grown by sulfurization using conventional and large-scale equipment.