Changes of Morphological, Optical, and Electrical Properties Induced by Hydrogen Plasma on (0001) ZnO Surface

Abstract

Plasma provides specific adjustment of solid‐state surface properties offering an alternative to high temperature treatment. Herein, hydrogen plasma treatment of monocrystalline (0001) ZnO surface is studied in an inductively coupled plasma reactor with reduced capacitively coupled plasma mode. The crucial role of electrical grounding of the sample holder for plasma etching and related changes in the morphology, optical, and electrical properties of surfaces exposed to electron and ion bombardment are explained. The effects on the chemical composition of the surface are analyzed by X‐ray photoelectron spectroscopy (XPS), optical properties by photoluminescence spectroscopy, topography, roughness, and surface measurements by atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM). All methods show altered ZnO surface properties before and after plasma treatment strongly depending on the electrical potential of the holder.

Polarization Controlled Assembly of Ultrathin Thiorphan Nanostructures on ZnO Surface Facets

“…21 The ZnO surface structure as well as photoluminescence can be modified by hydrogen plasma. 22 ZnO exhibits also a high adsorption capability and selectivity for photocatalytic dye removal 23 and wastewater treatment in general. 24 In addition to microscopic and spectroscopic methods, a more profound understanding of adsorption and interaction of molecules on surfaces benefits from computational simulations using methods such as density functional tight binding (DFTB) 25 and force field molecular dynamics simulations (FFMD).…”

“…For instance, ZnO is used for the treatment of various types of cancer diseases and ZnO nanoparticles are utilized in bioimaging because of their high stability and inherent photoluminescence properties . The ZnO surface structure as well as photoluminescence can be modified by hydrogen plasma . ZnO exhibits also a high adsorption capability and selectivity for photocatalytic dye removal and wastewater treatment in general …”