Fabrication of Silver-doped Zinc Oxide Thin Films Through Optimized Sol-Gel Deposition and Nanoparticle Wetting Process
Date of Award
Master of Science
Benjamin C Church, Konstantin Sobolev
p-type ZnO, Silver Doped, Silver Nanoparticle, Sol-gel, Thin Films, Zinc Oxide
Zinc Oxide (ZnO) has been of significant interest as a Transparent Conductive Oxide (TCO) given its sizable direct band-gap, and as a potential substitute for Indium-Tin Oxide for use in opto-electronic and piezo-electric devices, due to its comparatively abundant and nontoxic precursor materials. Sol-gel processing is an easy, low-energy method for fabricating ZnO thin films, and there has been increasing interest in doping the compound such to give it p-type semiconductive character.
This thesis thoroughly investigates sol-gel processing of ZnO thin solid films, with focus on wet-chemistry (sol-gel) methods of doping the material with silver (both as elemental ions and nanoparticles,) in the interest of achieving p-type doped ZnO. From dozens of similar but varying documented procedures, optimal processing methods and parameters for experimentation involving solutions-based doping were investigated and codified into a repeatable standard operating procedure (SOP), confirmed by X-Ray Diffraction results showing preferential (002)-peak, c-axis crystalline orientation. Heretofore unexplored study of the use of organic solvents as wetting agents and introduction of silver nanoparticles in layering processes within the sol-gel processing framework are shown to further improve c-axis orientation. A newly-adapted, quantified method of XRD preferential orientation analysis is implemented alongside UV-Visual bandgap analysis and SEM/AFM microscopy methods to further confirm improved crystallinity and reduced-diameter nanoscale c-axis oriented crystallites.
These experiments and characterizations are analyzed in the context of structure and properties leading to material performance, with results documented in detailed appendices.
Heintzkill, Reed T., "Fabrication of Silver-doped Zinc Oxide Thin Films Through Optimized Sol-Gel Deposition and Nanoparticle Wetting Process" (2018). Theses and Dissertations. 1993.