Syntheses, crystal and electronic structures of three new potassium cadmium(II)/zinc(II) tellurides: K{sub 2}Cd{sub 2}Te{sub 3}, K{sub 6}CdTe{sub 4} and K{sub 2}ZnTe{sub 2}

Three new ternary potassium(I) zinc(II) or cadmium(II) tellurides, namely, K{sub 2}Cd{sub 2}Te{sub 3}, K{sub 6}CdTe{sub 4} and K{sub 2}ZnTe{sub 2}, were synthesized by solid-state reactions of the mixture of pure elements of K, Cd (or Zn) and Te in Nb tubes at high temperature. K{sub 2}Cd{sub 2}Te{sub 3} belongs to a new structure type and its structure contains a novel two-dimensional [Cd{sub 2}Te{sub 3}]{sup 2-} layers perpendicular to the b-axis. K(5) cation is located at the center of five member rings of the 2D [Cd{sub 2}Te{sub 3}]{sup 2-} layer, whereas other K{sup +} cations occupy the interlayer space. K{sub 6}CdTe{sub 4} with a K{sub 6}HgS{sub 4} type structure features a 'zero-dimensional' structure composed of isolated CdTe{sub 4} tetrahedra separated by the K{sup +} ions. K{sub 2}ZnTe{sub 2} in the K{sub 2}ZnO{sub 2} structural type displays 1D [ZnTe{sub 2}]{sup 2-} anionic chains of edge sharing [ZnTe{sub 4}] tetrahedra separated by the potassium(I) ions. K{sub 2}Cd{sub 2}Te{sub 3}, K{sub 6}CdTe{sub 4} and K{sub 2}ZnTe{sub 2} revealed a band gap of 1.93, 2.51 and 3.0 eV, respectively. - Graphical abstract: Three new semiconducting K-Zn(Cd)-Te phases were synthesized. They feature 2D, 1D or 0D anionic structure made of corner- and edge-sharing or isolated MTe{submore » 4} tetrahedra.« less