Conduction band splitting and transport properties of Bi2Se3

Detailed transport studies of single crystals of Bi2Se3 were made in the temperature range of 2-300 K, and the data were analyzed in terms of a model consisting of two groups of electrons-a centrosymmetrical lower conduction band and an upper conduction band located away from the Gamma-point. Very good agreement with the experimental data is obtained assuming the electrons are scattered on acoustic phonons and ionized impurities. A rather strong influence of the latter mechanism is attributed to a large number of charged selenium vacancies in Bi2Se3. The fitted transport parameters were used to calculate the electronic portion of the thermal conductivity that, in turn, allowed for the determination of the lattice thermal conductivity. The Debye model provides a good approximation to the temperature dependence of the lattice thermal conductivity. (C) 2004 Elsevier Inc. All rights reserved.