Derivation of GdxZn1-xO Film: The Effects of Gd Concentration on the Structural, Morphological and Optical Properties

In recent years there has been renewed interest in zinc oxide semiconductor, mainly triggered by its prospects in optoelectronic applications. Doping ZnO with various elements has been a popular technique to gain the extrinsic properties for device applications. In this work we have studied the effect of Gadolinium (Gd) concentration on properties of sol–gel derived Gd doped ZnO films. The Gd concentration varying from 1 to 8 atomic percent (at.%). The structural, morphological and optical analyses were monitored by (XRD, Bruker D8 Advance), atomic force microscope (AFM, Tenko XE-100) and ultra violet-visible spectrophotometer (UV-Vis, Shimadzu UV 1800), respectively. Observations from the XRD results showed that all films exhibit the hexagonal wurtzite crystal structure and higher peak intensity observed at (002) peak. Based on XRD analysis, we also found that Gd concentration has a significant effect on the crystallite size and strain of the films. Moreover, the AFM analysis revealed that the surface become more uniform and denser as the Gd concentration increased. In addition, the optical transmittance spectra indicate that all films were highly transparent (>90%) in the visible range which slightly improved with increasing Gd concentration. The detail explanation on the mechanism will be discussed in detail in this paper.