Vanadium-induced deep impurity level in Pb_(1-x)Sn_xTe

摘要

The galvanomagnetic properties (T=4.2–300 K, B≤0.08 T) of Pb_(1-x-y)Sn_xV_yTe 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 r and of the Hall coefficient R_H 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 TcE40 K. In the alloy with xE0.2 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 Pb_(1-x-y)Sn_xV_yTe alloys was proposed.