Selective Area Growth of PbTe Nanowire Networks on InP

Abstract

Hybrid semiconductor–superconductor nanowires are promising candidates as quantum information processing devices. The need for scalability and complex designs calls for the development of selective area growth techniques. Here, the growth of large scale lead telluride (PbTe) networks is introduced by molecular beam epitaxy. The group IV‐VI lead‐salt semiconductor is an attractive material choice due to its large dielectric constant, strong spin‐orbit coupling, and high carrier mobility. A crystal re‐orientation process during the initial growth stages leads to single crystalline nanowire networks despite a large lattice mismatch, different crystal structure, and diverging thermal expansion coefficient to the indium phosphide (InP) substrate. The high quality of the resulting material is confirmed by Hall bar measurements, indicating mobilities up to 5600 cm2 (Vs)−1, and Aharonov–Bohm experiments, indicating a low‐temperature phase coherence length exceeding 21 µm. Together, these properties show the high potential of the system as a basis for topological networks.

In‐Plane Nanowire Growth of Topological Crystalline Insulator Pb1 − xSnxTe

“…The structure is single-crystalline over the entire length, with contrast lines visible in the HRTEM due to small-angle mosaicity. [18] For different x-values, the same crystalline quality is found (see Figure S4, Supporting Information).…”

“…By continuing the deposition for longer times and/or considering smaller opening sizes, shapes from all compositions are found to converge to a tetrahedron defined only by {200} facets, as shown in Figure 1c for PbTe (see also Ref. [18]), and for SnTe islands, grown in 100 nm openings for 45 min. This latter shape, to be considered as the final, steady‐growth morphology, looks consistent with the equilibrium morphology (Figure 1d), as predicted on the basis of ab‐initio surface energy values for both PbTe [ 19 ] and SnTe [ 20 ] in a Te‐poor environment.…”

“…Here, we investigate the in‐plane SAG of the Pb 1 − x Sn x Te ternary alloy over the full range of x from 0 to 1, by molecular beam epitaxy (MBE) growth, supported by phase‐field simulations. Growth is performed on InP(111)A substrates, as high quality PbTe growth has been shown on this specific substrate orientation in previous work, [ 18 ] and {111} facets can be readily exposed.…”

CdTe/Silica Nanospheres in a Lateral Flow Immunoassay for Prostate-Specific Antigen

“…32 This may be attributed to the alkaline growth environment of QDs at high temperatures and pressures that promotes recondensation of silicates. 29,33,34 The black dots with a size of approximately 3 nm in the TEM image (Figure 1c) directly evidence the successful growth of CdTe QDs in the DMSN-template, and the lattice of CdTe QDs is around 0.3 nm (inset in Figure 1d). 23,35 Meanwhile, the highresolution TEM (HRTEM) image of UQSN-115 is shown in Figure S2.…”

“…The large-area SEM image (Figure S1) and the corresponding inset show that the UQSN-115 surface has no apparent pore size, probably originating from the further hydrolyzed and rapidly reorganized −Si–O- bonds on the surface of DMSN-MPA . This may be attributed to the alkaline growth environment of QDs at high temperatures and pressures that promotes recondensation of silicates. ,, The black dots with a size of approximately 3 nm in the TEM image (Figure c) directly evidence the successful growth of CdTe QDs in the DMSN-template, and the lattice of CdTe QDs is around 0.3 nm (inset in Figure d). , Meanwhile, the high-resolution TEM (HRTEM) image of UQSN-115 is shown in Figure S2. As indicated in the TEM-high-angle annular dark field (TEM-HAADF) image (Figure e) of UQSN-115, the numerous bright spots indicate the high loading and homogeneous distribution of CdTe in the silica matrix, which is further supported by the energy-dispersive X-ray spectroscopy (EDS) elemental mappings (Figure f).…”