Co-Doped ZnO Thin Films: Experimental and DFT Insights into Structural, Optical and Magnetic Properties

Gültekin, ZAFER

doi:10.1016/j.physe.2025.116434

Co-Doped ZnO Thin Films: Experimental and DFT Insights into Structural, Optical and Magnetic Properties

Gültekin Z.

PHYSICA E: LOW-DIMENSIONAL SYSTEMS AND NANOSTRUCTURES, cilt.177, sa.11, ss.116434, 2026 (SCI-Expanded, Scopus)

Yayın Türü: Makale / Tam Makale
Cilt numarası: 177 Sayı: 11
Basım Tarihi: 2026
Doi Numarası: 10.1016/j.physe.2025.116434
Dergi Adı: PHYSICA E: LOW-DIMENSIONAL SYSTEMS AND NANOSTRUCTURES
Derginin Tarandığı İndeksler: Scopus, Science Citation Index Expanded (SCI-EXPANDED), Compendex, INSPEC
Sayfa Sayıları: ss.116434
Bursa Uludağ Üniversitesi Adresli: Evet

Özet

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.