Analysis of gamma dose dependent nanostructure, morphological, optical and electrical properties of CeO2 thin films

Abstract

The structural, morphological, optical and electrical properties of CeO2 thin films deposited on glass substrate using spin coating technique are studied with and without gamma irradiation. The prepared samples were gamma irradiated with 60Co at room temperature with dose range from 0 to 100 kGy. The pristine and gamma exposed samples were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive X-rays (EDX), UV–Vis Spectroscopy, photoluminescence (PL) and Hall measurements. XRD results confirmed the face-centered cubic phase of CeO2 for all samples and showing the decreased in the crystallinity with gamma irradiation dose values. The FESEM images shows that after gamma exposure, the CeO2 thin films surface became compressed, smooth and uniform. UV–Vis Spectroscopy determined that the shifting of energy band gap values accredited by creating or eradication of induced defects inside the energy band gap. PL peaks appeared in pristine and irradiated thin films can be allocated to the oxygen related defects. The mobility, electrical resistivity and carrier concentration were estimated for all sample by Hall measurements. It was found that the electrical properties, such as an increase in the number of carrier concentration and the decrease in the resistivity, of the CeO2 thin films were improved with gamma rays irradiation. The study successfully demonstrates that CeO2 thin films is a potential candidate to detect gamma radiation for dosemetric application.

Keywords

• Gamma irradiation
• XRD
• Energy band gap
• Photoluminescence
• Hall measurements