  The temperature dependences of the total, crystal lattice and electronic
thermal conductivities were investigated in films of topological insulators
p-Bi$_{0.5}$Sb$_{1.5}$Te$_{3}$ and p-Bi$_{2}$Te$_{3}$ formed by discrete and
thermal evaporation methods. The largest decrease in the lattice thermal
conductivity owing to the scattering of long-wavelength phonons on the grain
interfaces was observed in the films of solid solutions
p-Bi$_{0.5}$Sb$_{1.5}$Te$_{3}$ deposited by discrete evaporation on the
amorphous substrates of polyimide without thermal treatment. It is shown that
in the p-Bi$_{0.5}$Sb$_{1.5}$Te$_{3}$ films with low thermal conductivity the
energy dependence of the relaxation time is enhanced, which is specific for the
topological insulators. The electronic thermal conductivity was determined
taking into account the effective scattering parameter in the relaxation time
approximation versus energy in the Lorentz number calculations. The observed
increase of the electronic thermal conductivity within the temperature range of
40 - 80 K is related to the weakening of the electrical conductivity
temperature dependence and is determined by the increase in the effective
scattering parameter at low temperatures due to the effect of scattering on the
point antisite and impurity defects. A correlation was established between the
thermal conductivity and features of the morphology of the interlayer surface
(0001) in the studied films.
