To obtain a deep insight into the lattice characteristics of the NWs, TEM imaging were performed along the [−110] zone axis (cubic notation). Figure 3a shows the TEM image of a representative NW of the first group (with indium droplet top ends). The regions ‘1’ , ‘2’ , ‘3’ , and ‘4’ indicate the regions where the selected-area electron diffraction (SAED) analysis is performed. Note that region ‘1’ is on the indium droplet end, while

regions ‘2’ , ‘3’ , and ‘4’ are on the NW body. The SAED spectrum measured at ‘1’ , ‘2’ , ‘3’ , and ‘4’ is shown in Figure 3b,c,d,e, respectively. It can be observed that the 3-deazaneplanocin A purchase indium droplet shows poly-crystalline structures (metal) (see Figure 3b), while the NW body just below the indium droplet present zinc blende structure (InSb semiconductor) (see Figure 3c), which is consistent with previous results reported [15–17] for Au or Ag-catalyzed InSb NWs. The SAED pattern from Bafilomycin A1 manufacturer area 3 (Figure 3d) shows two sets of diffraction patterns [18], and both of them are [1–10] zone axis diffraction patterns.

One pattern indexed by 1 presents a relative 70.5° rotation with respect to the other pattern indexed by 2. 1111 coincides with 11-12, and two patterns reveal the same 111 plane class parallel to growth direction of NW. Figure 3f presents the structural diagram of rotation grain boundary. In Figure 3a, the dark contrast area represents the [1–10] orientation indexed by 1, while the bright contrast area represents the [1–10] orientation indexed by 2. The interfaces between bright areas and dark areas indicate the rotation grain boundaries. There are eight rotation grain boundaries in InSb NW as shown in Figure 3a. The SAED pattern from area 4 is shown in Figure 3e, which shows a cubic zinc blende, the same structure as that shown in Figure 3c. The second group

of InSb NWs (without indium droplet top ends) demonstrates the same lattice structure as the first Phosphoprotein phosphatase group InSb NWs with indium droplet top ends (SAED results are shown Additional file 3: Figure S3). Figure 3 TEM image and SAED pattern of an InSb NW. (a) TEM image of an InSb nanowire terminating with a droplet; (b) SAED pattern from the droplet shown in the area 1 of (a); (c) SAED pattern from area 2 shown in (a); (d) SAED pattern from area 3 shown in (a); (e) SAED pattern from area 4 shown in (a). (f) Structural diagram of rotation grain boundary. Figure 4a shows a typical longitudinal 2θ-ω XRD scan measured from InSb ensemble NW sample. The peaks at 23.8° and 76.3° arise from the 111 and 333 reflections of zinc-blende-structured InSb, respectively [12]. All the observed InSb reflections match those of Si (111), indicating the epitaxial growth of InSb NWs facilitate perpendicular to the Si substrate.