We studied the dark conductivity in pure and doped TlBr crystals obtained by Bridgman at various compositions and pressures of the residual vapors above the melt. The resistivity of pure crystals at room temperature was (0,7—2) ⋅ 10¹⁰ ohm ⋅ cm and that of doped crystals depended on the amount of introduced impurity Pb and reached 1,8 ⋅ 10¹¹ ohm ⋅ cm. The activation energy of conductivity near room temperature was 0,8—0,85 eV and 0,6—1,2 eV for pure and doped crystals, respectively. The activation energy of conductivity in the investigated crystals is consistent with the known values of formation and displacement energies for Schottky defects in TlBr at high temperatures. An expression for the dependence of conductivity on content of this divalent cation Pb in crystal was obtained. The equilibrium concentration of point defects in the investigated pure TlBr crystals was calculated as 6,4 ⋅ 10¹⁴ cm⁻³. The mobility of displacement of the anionic and cationic vacancies were μ_a = 9,8 ⋅ 10⁻⁷ cm² ⋅ V⁻¹ ⋅ c⁻¹ and μ_c = 3,4 ⋅ 10⁻¹⁰ cm² ⋅ V⁻² ⋅ c⁻² respectively.

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