Polaronic and Electrochemical Signatures in Group IVB (Ti, Zr, Hf) Oxides: Unified SKP-DFT Insights for Tunable Transport in Energy and Electronic Devices

• Type: Article in International Scientific Journal
• Date: 2025

Authors

Beatriz Moura Gomes (Author) FEUP; Júlia Holtz (Author) Other; Maria Luís Pinto (Author) Other; Maria Helena Braga (Author) FEUP

Journal

The Journal is awaiting validation by the Administrative Services.

Title: ADVANCED FUNCTIONAL MATERIALS

ISSN: 1616-301X

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Associated Projects

LAETA2023 - Programático - ET - Emerging Technologies - LAETA2023 - Programático - ET - Emerging Technologies

CVB - CVB - Cadeia de Valor das Baterias em Portugal

NGS -New Generation Storage - NGS -New Generation Storage

PULSELiON - PUlsed Laser depoSition tEchnology for soLid State battery manufacturIng supported by digitalizatiON

Other information

Authenticus ID: P-019-KEQ

DOI: 10.1002/adfm.202509853

Abstract (EN): Understanding interfacial energetics and transport mechanisms in transition metal oxides is key to unlocking their potential in microelectronics, memory, and energy harvesting and storage. Here, a unified electrochemical potential scale is established for the group IVB oxides TiO2, ZrO2, and HfO2, combining spatially resolved scanning Kelvin probe microscopy with hybrid and density functional theory (DFT) simulations. These results show good agreement between DFT-predicted absolute chemical potentials and experimental surface potentials across multiple electrode configurations and surface terminations. ZrO2 exhibits unexpected emergent behavior under open-circuit conditions, forming ordered potential patterns suggestive of internal charge separation and Odelta- transport. TiO2 shows dynamic sensitivity to contact polarity and termination, while HfO2 reveals elevated, orientation-dependent potentials linked to spontaneous ferroelectricity. Complementary temperature-dependent conductivity and Hall effect measurements expose thermally activated polaronic transport (Fr & ouml;hlich model), in all three oxides, including sharp transitions and topological conduction thresholds in HfO2. Simulated charge-discharge cycles further demonstrate field-tunable conductivity and mobility. These findings redefine these oxides as active electrochemical materials, not merely inert dielectrics, and provide a predictive framework for rational interface design in reconfigurable electronics and ion-electron hybrid devices.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12