Growth of Aligned Sb- and Ga-doped Zinc Oxide Nanorod Arrays using Hydrothermal for Triboelectric Nanogenerators

Abstract

This dissertation proposes a plan for exploring the effect of doping on triboelectrification (contact electrification) The proposed triboelectric nanogenerator is composed of a series of Sb- and Ga-doped nanorod arrays with various carrier concentrations fabricated using hydrothermal via doping rubbing with polydimethylsiloxane (PDMS) or nylon Regarding electron transfer in triboelectrification the thermionic model indicates that the Fermi-Dirac distribution function dominates and that the change in electron transfer behavior is expected to occur when a semiconducting zinc oxide nanorod array is doped The first part of this dissertation describes the proposed triboelectric nanogenerator consisting of a series of Sb-doped nanorods arrays with various carrier concentrations rubbing versus negatively charged triboelectric PDMS and positively charged triboelectric nylon with the applied force in contact-separation mode The results demonstrate that output current density is correlated with carrier concentration The electric conductivity and carrier concentration are determined using conductive atomic force microscopy Counterintuitively p-type zinc oxide contributes more electrons to the PDMS counterpart than does an undoped sample X-ray photoelectron spectroscopy indicates that the high electron concentration on the surface is due to Sb+3 ions and reflects the above-half-energy-band-gap valence band maximum as characterized by ultraviolet photoelectron spectroscopy Therefore surface downward band bending likely explains the eccentric behavior The second part of this dissertation describes the proposed triboelectric nanogenerator consisting of a series of Ga-doped nanorod arrays with various carrier concentrations The output current density of the triboelectric nanogenerator increased with increasing carrier concentration The photoluminescence for the energy band gap exhibits the Burstein-Moss effect after doping Photoelectron spectroscopy indicates that Ga replaces the position of Zn leading to a chemical shift of O-2 The corresponding valence band maximum and work function for a series of Ga-doped samples show increasing and decreasing trends respectively The schematic energy band diagrams show an initially upward and then flat or slightly downward band condition which describes the tendency in electron transfer from n-type Ga-doped nanorods to PDMS

Date of Award	2020
Original language	English
Supervisor	Chuan-Pu Liu (Supervisor)