Carrier Mobilities in Pb1−xSnxTe Alloys

Experimental measurements on the transport properties in Pb1−xSnxTe single-crystal alloys at 77°K have been made as a function of both carrier concentration and composition. The measurements were made on p-type materials, primary interest being in the carrier concentration range where impurity scattering was clearly dominant (p≥1×1019 cm−3). The entire compositional range has been studied and the results reveal the following compositional regions with differing transport characteristics: (1) the region containing from 2- to 5-mol% SnTe, where there is a rapid decrease in hole mobility at any given carrier concentration, (2) the region from 5- to 37-mol%, where the hole mobilities are essentially independent of composition, (3) the region from 37- to 40-mol% SnTe, where a distinct discontinuity in the hole mobility occurs, and (4) the region from 40- to 100-mol% SnTe, where the hole mobility gradually increases with tin content.