Effects of Al dopant on XRD, FT-IR and UV–vis properties of MgO films

Highlights: • Undoped and Al doped MgO films have been produced on glass substrates. • XRD analysis confirmed the cubic structure. • Al doping decreased optical band gaps of the MgO film. -- Abstract: Undoped and Al doped MgO films have been prepared by a sol–gel spin coating method. The crystalline structural, optical, vibrational and morphological properties of the Al doped MgO films were characterized by different techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis absorption spectra, and Fourier transform infrared (FT-IR) measurements. XRD patterns confirm that the films were polycrystalline cubic nature. The crystallite size of the films slightly changed with increasing the Al dopant content. The optical band gap of the films was found to decrease from 3.92 to 3.84 eV by Al incorporation. The FT-IR spectroscopy confirms the presence of MgO. The observed vibrational bands at 679 and 862 cm⁻¹ revealed the existence of the cubic MgO bonds. Surface morphology of the films was significantly affected by Al doping.