Abstract

Ab initio molecular dynamics simulations and hybrid functional electronic structure calculations are employed to determine the formation, the structural and electronic properties, and the dynamics of covalent (In-OH) and ionic (In-H-In) hydrogen defects at crystalline-In2O3/amorphous-In2O3−x interface. This comprehensive computational study considers (i) various interstitial and substitutional hydrogen site locations within the crystalline, amorphous, and interfacial regions; (ii) several oxygen-to-hydrogen ratios; and (iii) possible defect charged states. The results reveal hydrogen's inability to fully passivate the undercoordinated under-shared in atoms in amorphous highly substoichiometric oxide, giving rise to the formation of deep electron traps even in net-charge neutral structures. These trap defects are found to be sensitive to photoexcitation, in contrast to In-OH with H's electronic states located below the valence band and to In-H-In, where H is found to maintain its charge state upon illumination. Nevertheless, H plays a critical role in photoinduced conductivity and its relaxation by promoting In-O coordination transformations at the interfacial region, including deterioration of the crystalline layer. The results help identify mobile H species and metastable H defect complexes (such as In-H-H-In, In-OH–H-In, and In-OH–O-In) that are responsible for long relaxation times of the conductivity decay.

Department(s)

Physics

Publication Status

Full Access

Comments

Missouri University of Science and Technology, Grant DMR‐1729779

Keywords and Phrases

ab initio molecular dynamics; crystalline/amorphous interfaces; H defects; transparent conducting metal oxides

International Standard Serial Number (ISSN)

1862-6270; 1862-6254

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Wiley, All rights reserved.

Publication Date

01 Jan 2025

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Physics Commons

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