Аннотация:Galvanomagnetic and photoelectric properties of Pb1-ySnyTe(0≤y≤0.06) and Pb1-xGexTe (0.04≤x≤0.08)single crystals doped with gallium (CGa=0.3÷3 mol.%) have been investigated. Low temperature activation ranges of the impurity conductivity on the dark curves of ρ(1/T) were revealed and attributed to the appearance of gallium-induced deep level in the gap of the alloys. It was shown that the alloys possess high infrared photosensitivity at temperatures below Tc=50÷60 K. A model assuming that doping with gallium leads to the formation of two different gallium-related defect levels in the energy spectrum of the PbTe-based alloys was proposed.