Optoelectronic transport and antibacterial properties driven by surface defects in micro- and nanoscale oxides of zinc and gallium.

Brannon, John Hunter

Item

Optoelectronic transport and antibacterial properties driven by surface defects in micro- and nanoscale oxides of zinc and gallium.

Brannon, John Hunter

Date

2025-12-08

Abstract

Zinc oxide (ZnO) and beta-gallium oxide (β-Ga2O3) are semiconductors with bandgap energies of approximately 3.4 eV and 4.8 eV, respectively. These materials are utilized across diverse applications, including pharmaceuticals, radiation shielding, etc. Our investigation addresses: (1) antimicrobial properties of Zn- and Ga-containing metal oxides, and (2) studies of the role of hydrogen in the persistent n-type conductivity of β-Ga2O3. Ga- and Zn-containing metal oxides present alternative antibacterial pathways mediated by surface chemistry and defect states that are not fully understood. β-Ga2O3 is promising for high-power electronics, but its persistent n-type behavior restricts applications. Iron doping of ZnO is used to possibly reduce Zn-cation release from surface, a suggested driver of ZnO’s antibacterial activity. GaOOH particles with different defect levels and morphologies show varied antibacterial efficacy against S. aureus and E. coli. β-Ga2O3 microcrystals are treated with remote hydrogen plasma to elucidate hydrogen’s behavior as a contributor to persistent n-type conductivity.