Syntheses, crystal and electronic structures of three new potassium cadmium(II)/zinc(II) tellurides: K2Cd2Te3, K6CdTe4 and K2ZnTe2

Three new ternary potassium(I) zinc(II) or cadmium(II) tellurides, namely, K 2 Cd 2 Te 3 , K 6 CdTe 4 and K 2 ZnTe 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 2 Cd 2 Te 3 belongs to a new structure type and its structure contains a novel two-dimensional [Cd 2 Te 3 ] 2− layers perpendicular to the b -axis. K(5) cation is located at the center of five member rings of the 2D [Cd 2 Te 3 ] 2− layer, whereas other K + cations occupy the interlayer space. K 6 CdTe 4 with a K 6 HgS 4 type structure features a “zero-dimensional” structure composed of isolated CdTe 4 tetrahedra separated by the K + ions. K 2 ZnTe 2 in the K 2 ZnO 2 structural type displays 1D [ZnTe 2 ] 2− anionic chains of edge sharing [ZnTe 4 ] tetrahedra separated by the potassium(I) ions. K 2 Cd 2 Te 3 , K 6 CdTe 4 and K 2 ZnTe 2 revealed a band gap of 1.93, 2.51 and 3.0 eV, respectively.