Materials design for Cu-based quaternary compounds derived from chalcopyrite-rule

The stability of the Cu2–II–IV–VI4 and Cu–III–IV–VI4 compounds (II=Zn, Cd; III=Ga, In; IV=Si, Ge, Sn; VI=S, Se, Te) as tetrahedral coordinated structures has been investigated by means of the electronegativity combination analysis of compositional elements. As compared with the results of the products synthesized from respective elemental mixtures, the possibility of crystallization in the form of tetrahedral coordinate compounds and the crystal structure are found to be expected by this semi-theoretical analysis. These melting points and lattice constants determined from the results of differential thermal analysis and powder X-ray diffraction, respectively, are found to vary linearly with increasing of mean atomic weight, and can be established from the empirical equations.