Exploring the structural and electronic properties of CeO₂ thin films: role of thickness, temperature, and oxygen vacancies

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Gunaydin S., Cengiz E., Kanmaz I., APAYDIN G., Miyazaki H., Harfouche M., ...More

JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, vol.27, no.11-12, pp.587-595, 2025 (SCI-Expanded, Scopus)

• Publication Type: Article / Article
• Volume: 27 Issue: 11-12
• Publication Date: 2025
• Journal Name: JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS
• Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex
• Page Numbers: pp.587-595
• Karadeniz Technical University Affiliated: Yes

Abstract

Systematic investigation of the temperature-dependent local arrangements in CeO2 thin films and their direct impact on electronic properties is presented. Results revealed that thicker films promote oxygen vacancy formation, reducing Ce(4+ )to Ce3+ and modifying the local coordination. Furthermore, temperature-dependent EXAFS analysis uncovers a local structural rearrangement transition above 400 K, driven by thermal activation of oxygen vacancies. This rearrangement, occurring within a globally stable cubic framework, directly alters the hybridization between Ce 4f/5d and O 2p orbitals. Density Functional Theory (DFT) calculations corroborate the experimental findings, revealing an indirect bandgap of 1.60 eV as a result of orbital hybridization.