CONTROL OF HOLE CONCENTRATION IN LIQUID-PHASE EPITAXIAL LAYERS OF PBTE BY AS DOPING

Liquid-phase epitaxial layers of PbTe grown at {reversed tilde equals}55O‡C have been doped p-type over the concentration range 5 × 1016 - 5 × 1018cm-3by adding from 0.004 - 10 at.% arsenic to the melts. The hole concentrations of the layers, which were grown on p+ substrates, were obtained from plasma reflectivity and thermoelectric probe measurements. The latter assessment technique is shown to be a reliable and simple method for determining the hole concentration in epitaxial layers with thicknesses greater than ≃ 5ym, provided the damage introduced by the probe is controlled. Damage can cause negative thermoelectric power signals to be obtained from p-type PbTe, showing that dislocations introduce donor centres in this material. © 1979 AIME.