Zinc Oxide Nanostructures Fabricated under Extremely Non-Equilibrium Plasma Conditions

Abstract

In the present work, extremely non-equilibrium, high temperature and high density argon plasma is used for producing ions from pellet of zinc oxide (ZnO) fitted on top of anode. These ions along with energetic argon ions move vertically upward in a fountain like structure in post focus phase of plasma dynamics and material ions get deposited on the glass substrates placed at 4.0 cm from anode top. This process of production of material ions from ZnO pellet leads to nucleation and nanostructures formation with one and two bursts of focused plasma. The surface morphology studied using scanning electron microscopy shows the formation of nanostructures with mean size about 8 nm. The structural properties of nanostructures in X-ray diffraction pattern show [100] and [002] planes of hexagonal ZnO. Photoluminescence studies show peaks related to defect transitions. The band-gap of nanostructures found from Tauc plot is smaller than that of the bulk ZnO. The resultant morphological, structural and optical properties of nanostructures suggest the possible applications in visible optoelectronic devices.