Nano/Micro-Structured ZnO Rods Synthesized by Thermal Chemical Vapor Deposition with Perpendicular Configuration

Abstract

Under a one-step process, catalyst-free growth of one-dimensional (1D) ZnO hierarchical nanostructures was performed on ZnO-seeded Si substrate by thermal chemical vapor deposition with a perpendicular setup. The morphological and crystallographic properties of the nano/micro-structured ZnO rods were investigated with varying growth temperature and growth time. X-ray diffraction patterns of 1D ZnO double-structured rods showed the hexagonal wurtzite structure. The morphology and crystal structure of the ZnO double-structured rods were sensitive to the growth temperature and growth time. From Raman scattering and photoluminescence spectra, the orientation and size effects of the ZnO double-structured rods were discussed in relation to growth temperatures and growth times.

Keywords: ZnO double-structured rods; nano/micro-structured ZnO rods; one-dimensional ZnO hierarchical nanostructures; one-step process; perpendicular configuration; thermal chemical vapor deposition.

Figure 1

FE-SEM images of ZnO double-structured rods grown on ZnO-coated Si substrates by thermal CVD with perpendicular setup as functions of growth temperature and growth time: at 700 °C for (a) 20 min, (b) 40 min, and (c) 60 min; at 800 °C for (d) 20 min, (e) 40 min, and (f) 60 min; at 900 °C for (g) 20 min, (h) 40 min, and (i) 60 min.

Figure 2

(a) EPMA and (b) EDS spectra of ZnO double-structured rods grown at a growth temperature of 700 °C for a growth time of 60 min.

Figure 3

XRD patterns of the ZnO double-structured rods grown on ZnO-coated Si substrates at a growth temperature of (a) 700, (b) 800, and (c) 900 °C.

Figure 4

Raman scattering spectra of the ZnO double-structured rods grown at a growth temperature of (a) 700, (b) 800, and (c) 900 °C.

Figure 4

Raman scattering spectra of the ZnO double-structured rods grown at a growth temperature of (a) 700, (b) 800, and (c) 900 °C.

Figure 5

PL spectra of the ZnO double-structured rods grown for a growth time of 60 min under different growth temperatures. The insets correspond to Figure 1c,f,i.