High-Mobility Epitaxial Layers of PbTe and Pb1−xSnxTe Prepared by Post-Growth Annealing

Abstract

Postgrowth annealing has been found to give layers of PbTe and Pb1−xSnxTe (with x ≈ 0.2) with much larger low-temperature Hall mobilities than as-grown layers. At temperatures down to about 50 °K the Hall mobilities are close to those of good bulk crystals. Below 50 °K there is a tendency to saturation at values greater than 105 cm2 V−1 sec−1. Structural studies indicate that both as-grown and annealed specimens are single crystals with about the same concentration of low-angle grain boundaries as the BaF2 substrates. It is suggested that the annealing process removes an excess of native defects.