Defect Free PbTe Nanowires Grown by Molecular Beam Epitaxy on GaAs(111)B Substrates

The molecular beam epitaxial growth of PbTe nanowires on GaAs(111)B substrates is reported. The growth process was based on the Au-catalyzed vapor−liquid−solid mechanism. These nanowires grow along the [100] axis; they are perpendicular to the substrate, have tapered shapes, and have diameters of about 90 nm at the base and 60 nm at the top. High resolution transmission electron microscopy pictures reveal that the PbTe nanowires have a rock-salt structure and, in contrast to the one-dimensional structures of III−V and II−VI compound semiconductors such as GaAs, InAs, or ZnTe, are free from stacking faults. A theoretical analysis of these experimental findings, which is based on ab initio modeling of the PbTe nanowires, is also presented.