Structural, morphological characteristics and optical properties of Y doped ZnO thin films by sol–gel spin coating method

Un-doped and Y doped ZnO thin films were deposited successfully by sol–gel spin coating method with different Y concentrations. The X-ray diffraction spectra revealed that all the films have polycrystalline of hexagonal wurtzite structure. SEM images of the films show different micro structure with nano clusters and show a reduction in surface roughness. The EDX spectrum confirms the presence of Zn, O and Y elements in the prepared films. The optical transmittance spectrum indicates the average transmittance of the films is increased from 78% to 83%. The optical band gaps of the ZnO films were changed from 3.33 eV to 3.43 eV with increasing Y doping. PL spectra show the blue shift in near band edge (NBE) UV emission. The presence of functional groups and the chemical bonding is confirmed by FTIR spectra. The Hall measurements show that the films have n-type conductivity.