Low-temperature growth of highly crystalline ZnO nanopillars by mist chemical vapor deposition technique

Abstract

Highly crystalline ZnO nanopillars were successfully synthesized using the mist chemical vapor deposition (Mist-CVD) technique. This environmentally friendly and low-cost method operates under atmospheric pressure and low temperatures. By varying the growth temperature from 300C to 500 ∘ C, we demonstrated control over the structural, optical and morphological properties of ZnO. X-ray diffraction (XRD) analysis confirmed a transition in the preferential growth orientation from (100) to (002) as the temperature increased, with nanopillars showing a highly c-axis orientation at 450 ∘ C. SEM and AFM analyses revealed vertically aligned, homogeneously distributed nanopillars with high surface roughness, favorable for photocatalytic applications. Optical transmittance decreased with growth temperature, while the bandgap narrowed due to intrinsic defects. These findings highlight the potential of Mist-CVD for producing high-quality ZnO nanostructures tailored for advanced applications.