Electrical properties of bismuth telluride doped with bismuth iodide

Electrical conductivity and Hall coefficient of single crystals of Bi2Te3 doped with 3 wt% BiI3 are measured in the temperature range 100 to 450 K. The concentrations of holes and electrons, their mobilities and activation energies are calculated without using any extrapolated value of temperature variation of conductivity. The value of the activation energy obtained from the temperature variation of concentration of free carriers agrees fairly well with that obtained from the temperatures variation of electrical conductivity. (author)