Thin Solid Films, Vol.631, 213-218, 2017
The influence of oxygen partial pressure on the shape transition of ZnO microstructure by thermal evaporation
One-dimensional (1-D) and two-dimensional (2-D) wurtzite zinc oxide (ZnO) microstructures were grown on indium tin oxide (ITO)/borosilicate glass substrates via oxygen-assisted thermal chemical vapor deposition (CVD) using zinc (Zn) powder as a precursor with different flow rates of ultra-high purity nitrogen carrier gas (N-2) at the total pressure of 450 Pa and temperature of 550 degrees C. The structural and optical properties of the synthesized ZnO microstructures were investigated using field-emission scanning electron microscopy, X-ray diffraction (XRD) and photoluminescence (PL) as a term of oxygen (O-2) partial pressure. The obtained microstructure evolved from micropin to micropillar and to microsheet in correspondence with the increase of O2 partial pressure. XRD confirmed the transition from 1-D to 2-D microstructure with defects observed from PL spectra. The experiment suggested that the increase of supersaturation in the vapor-solid (VS) growth mechanism caused the shape transition. (C) 2017 Elsevier B.V. All rights reserved.