Electrical properties of indium-doped LPE layers of Pb1?xSnx Te

Liquid-phase epitaxial (LPE) layers of Pb_1−xSn_xTe with an alloy composition 0≤×≤0.25 were doped n-type by adding from 0.002 to 10 at.% indium to the growth solution. Doping characteristics of indium and electrical properties of the epilayers at 77 and 4.2K were studied by Hall and resistivity measurements made directly on the grown layers. Electron concentration and mobility at 77 and 4.2K are presented as a function of indium doping for various x values. Doping coefficients of ~0.05 and ~0.03 are found for PbTe and Pb_0.8Sn_0.2Te, respectively, grown at ~450°C. For medium to high indium doping, the electron concentration saturates to a constant value independent of doping and LPE growth temperature. The saturation values decrease substantially with increasing x and increase with a decrease in sample temperature. Bulklike mobilities practically independent of doping are recorded up to an indium concentration N_ln~0.3 at.%, above which the mobility decreases with increasing indium concentration. The data shows that indium is a suitable donor in liquid-phase epitaxial layers of Pb_l-XSn_xTe.