Effect of Deviation from Stoichiometry on Thermal Conductivity of Bi2Se3 Polycrystals

Abstract

The dependences of electronic and lattice thermal conductivity on the composition (59.9 - 60.0) at. % Se of Bi2Se3 polycrystals subjected to a long-term annealing at 650 K. A non-monotonic behavior of these concentration dependences, associated with a change in the phase composition and defect structure under the deviation from stoichiometry, was observed. The boundaries of the Bi2Se3 homogeneity region were estimated. The results of the present work confirm those obtained earlier in our study of the effect of deviation from stoichiometry (59.9 - 60.0 at.% Se) on the electrical conductivity, Hall coefficient, Seebeck coefficient and microhardness of Bi2Se3polycrystals after a similar preparation technology.