Electronic and ionic zeebeck coefficients in mixed conductors of Ag 0.25–δ Cu 1.75 Se, Ag 1.2–δ Cu 0.8 Se

The paper presents the studies of ionic and electronic Zeebeck coefficients and electronic conductivity in nonstoichiometric Ag0.25–δCu1.75Se, Ag1.2–δCu0.8Se solid solutions existing on the basis of the cubic phase of copper selenide. It is shown that Ag1.2–δCu0.8Se is a bilateral variable composition phase manifesting inversion of the sign of predominant charge carriers under variation of the chemical composition by silver within the homogeneity region. Mobilities of electrons and electron holes are estimated on the basis of the concentration dependences.