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

Abstract

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.

Chemical Transformations in Ultrathin Chalcogenide Nanowires

“…That is because free energy of formatin of cubic PbTe is less than the high-pressure phase in ambient condition, which is under thermodynamic control. 57,58 In the case of CdTe and ZnTe transformation, however, there should be no special preference for zinc blende and wurtzite in light of a very small difference of free energy of formation between wurtzite and zinc blende structure (7.0 and 6.4 meV for CdTe and ZnTe, respectively). 60 Nevertheless, the major crystal structure of resultant CdTe and ZnTe nanowires was found to be zinc blende, although a small portion of wurtzite-structured products was observed.…”

Bi catalyzed VLS growth of PbTe (001) nanowires

“…This set of planes is the lowest free-energy surfaces in IV-VI semiconductors [14][15][16][17], that makes {1 0 0} faceting energetically favorable for PbTe nanocrystal structures. The faceting has been observed previously for Ga-Au catalyzed (0 0 1) PbTe NWs on GaAs (1 1 1) B substrates prepared at the same substrate temperature [14]. In contrast to our case, PbTe NWs on GaAs had tapered shape and different substrate orientation therefore faceting with other sets of plains was also present.…”

Defect-free SnTe topological crystalline insulator nanowires grown by molecular beam epitaxy on graphene

“…1c and 1d indicate that NWs have square cross sections, which corresponds to [001] NW growth axes. We have observed previously that, in contrast to III-V and II-VI semiconductor NWs which usually grow along [111] crystallographic direction, the IV-VI NWs naturally grow along [001] direction, 25 which implies their 4-fold axial symmetry and square cross section.…”