**6.3 Indium catalyst removal**

Residual indium could be removed by a simple chemical method consisting of soaking samples in 5% hydrochloric acid (HCl) solution (**Figure 12**). The reaction

#### **Figure 11.**

*EDS spectra of a wire performed (a) in the middle, (b) on the top, and (c) on the particle catalyst as shown in (d).*


#### **Table 1.**

*Atomic percentage of silicon and indium in a grown silicon wire.*

**Figure 12.** *Illustration of the experimental protocol used.*

**Figure 13.** *SEM images of SiNWs (a) before and (b) after catalyst elimination.*

between In and HCl could potentially produce two types of indium chloride: InCl2 or InCl4. **Figure 13** shows the grown silicon nanowires before and after indium catalyst elimination.
