Temperature dependence of the electrical conductivity and thermoelectric power in MoTe₂ single crystals

Abstract

Abstract Thermoelectric power and de electrical conductivity measurements are made on MoTe 2 single crystals in a wide temperature range (77 to 770 K). The results are analyzed on the basis of impurity conduction. It is shown that three processes contribute to the total conductivity: hopping conduction between impurity sites, scattering by optical modes, and, in the intrinsic domain, scattering by impurities. The thermal energy gap (0.99 eV) is approximately the same as the optical one (1.03 eV). The effective mass of electrons in the conduction band is not very different from the mass of the free electron ( m * = 0.76 m ), and the dielectric constant of the medium is K ≈︁ 34. The agreement between theoretical and experimental results is quite good. A comparison with previous results performed on compact polycrystalline samples is given.