Vanadium-induced deep impurity level in Pb1-xSnxTe

The galvanomagnetic properties (T=4.2-300 K, B≤0.08 T) of Pb1-x-ySnxVyTe alloys (x=0.06-0.26, y=0.002-0.066) have been investigated. Low temperature activation range of the impurity conductivity on the temperature dependencies of resistivity ρ and of the Hall coefficient RH in the heavily doped samples has been revealed and attributed to the appearance of vanadium-induced deep level in the gap of the alloys. It was found that in insulating phase alloys possess a high photosensitivity to IR excitation at temperatures up to Tc∼40 K. In the alloy with x∼0.2 the metal-insulator transition due to the shift of the Fermi level from the valence band to the gap with the increase of the vanadium and tin content and the pinning of the Fermi level by vanadium level were observed. The diagram of electronic structure reconstruction for Pb1-x-ySnxVyTe alloys was proposed.