Dopant-induced modulation of acetone sensing in SILAR-grown MgO thin films

Pure and transition-metal-doped MgO thin films were synthesized by the SILAR method. The effects of Fe, Mn, and Ni doping on structural, optical, surface, and acetone sensing properties were systematically examined. XRD confirmed single-phase cubic MgO with a preferred (200) orientation, while doping altered crystallite size and lattice parameters. SEM and EDX analyses revealed uniform surface morphology and successful dopant incorporation. XPS verified the chemical states of Mg, O, and the dopant elements. UV–Vis results showed dopant-dependent changes in optical absorption and band gap, associated with defect states and lattice distortion. Acetone sensing tests demonstrated that doped films exhibited higher responses than pure MgO, depending on dopant type. The improved performance was attributed to increased surface defects, enhanced charge transfer, and catalytic effects of dopants. Overall, SILAR-grown doped MgO thin films showed strong potential for acetone detection applications.