Experimental investigation of structural and optical properties of Mn-doped ZnO thin films deposited by pneumatic spray technique

Mn-doped ZnO thin films with varying Mn concentrations were synthesized on glass substrates using the pneumatic spray technique. Energy-dispersive X-ray (EDX) analysis confirmed the substitution of Zn by Mn in the ZnO matrix. X-ray photoelectron spectroscopy (XPS) revealed characteristic spin-orbit energy states of Zn:2p and Mn:3d, indicating strong Mn-ZnO interactions. Microstructural analysis showed non-uniform extended lines and spherical grains, with decreasing grain size as Mn concentration increased. X-ray diffraction (XRD) confirmed a polycrystalline hexagonal structure, with experimentally determined lattice parameters a = 3.1453 Å, c = 5.1353 Å, in agreement with CASTEP calculations. Optical measurements indicated ~ 80% absorbance in the visible range, with a shift from blue to red as Mn content increased, suggesting bandgap modulation. These findings highlight the potential of Mn-doped ZnO films for tunable optoelectronic applications.