DIMENSIONAL REDUCTION IN II-VI-MATERIALS - A(2)CD(3)Q(4) (A=K, Q=S, SE, TE, A=RB, Q=S, SE), NOVEL TERNARY LOW-DIMENSIONAL CADMIUM CHALCOGENIDES PRODUCED BY INCORPORATION OF A(2)Q IN CDQ

The synthesis of the isomorphous layered chalcogenides K2Cd3S4 (I), Rb 2Cd3S4 (II), K2Cd3Se4 (III), Rb2Cd3Se4(IV), and K2Cd3Te4(V) in molten A(2)Q(x) fluxes is reported (A = K, Rb; Q = S, Se, Te; x = 2 to 3): Th e compounds form as (Cd(3)Q(4))(n)(2n-) layers interspersed with A(+) cations; the layers are composed of Cd(3)Q(4)(2-) units shaped as trun cated cubes. The compounds have room-temperature band gaps of 2.75, 2. 93, 2.36, 2.37, and 2.26 eV for I, II, III, IV, and V, respectively, a nd also display strong photoluminescence. The thermal analysis data fo r all compounds are reported. The properties of these compounds are co mpared with those of the three-dimensional compounds CdS, CdSe, and Cd Te, as well as those of the nanometer-sized CdQ clusters. A conceptual contest is presented to connect all these different types of compound s.