Texture inheritance in thin-film growth of Cu2ZnSnS4

The growth mechanism of Cu2ZnSnS4 thin films is studied starting from highly textured ZnS precursor films. These precursors were converted to Cu2ZnSnS4 by subsequent deposition of Cu, Sn, and S at high temperatures. Orientation measurements revealed that the ⟨111⟩ texture of the ZnS precursor is inherited by the Cu2ZnSnS4 layer. On the basis of texture and transmission electron microscopy measurements, a growth model is proposed. According to this model, the initial formation of Cu2ZnSnS4 nuclei is controlled by a topotactic or epitactic mechanism with respect to the ZnS precursor. The further growth of the Cu2ZnSnS4 grains appears to be independent of the precursor lattice.