Co-Doped ZnO Thin Films: Experimental and DFT Insights into Structural, Optical and Magnetic Properties
PHYSICA E: LOW-DIMENSIONAL SYSTEMS AND NANOSTRUCTURES, vol.177, no.11, pp.116434, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 177 Issue: 11
- Publication Date: 2026
- Doi Number: 10.1016/j.physe.2025.116434
- Journal Name: PHYSICA E: LOW-DIMENSIONAL SYSTEMS AND NANOSTRUCTURES
- Journal Indexes: Scopus, Science Citation Index Expanded (SCI-EXPANDED), Compendex, INSPEC
- Page Numbers: pp.116434
- Bursa Uludag University Affiliated: Yes
Abstract
In this work, we systematically investigate the structural, optical, and magnetic properties of undoped and Co-doped ZnO thin films prepared by the sol–gel method, supported by DFT (Quantum ESPRESSO) calculations. XRD analysis confirms the retention of the hexagonal wurtzite phase, while Co incorporation leads to c-axis expansion, reduced crystallite size, and increased microstrain and a moderate expansion along the c-axis associated with strain- and defect-mediated lattice perturbations. UV-Vis spectra reveal a band-gap narrowing and redshift, consistent with Co 3d-derived intermediate states near the band edges. Photoelectrochemical measurements (Mott–Schottky and time-resolved photocurrent) show an increase in carrier density and enhanced photocurrent under UV illumination. VSM measurements demonstrate room-temperature ferromagnetism, and DFT reveals spin-asymmetric density of states and Co-centered magnetic moments, which provide a microscopic rationale for these experimental findings.