Structural and optical studies on Nd doped ZnO thin films

•Grain size of the Nd doped ZnO layers varies from 50 nm to 76 nm by SEM.•From Raman, the LO phonon is slightly red-shifted and broadened.•Presence of crystalline defects in the ZnO lattice confirmed was by Raman studies.•A red shift was also observed for Nd doping of ZnO thin films confirmed by PL.

Thin films of Zn1−xNdxO were deposited by spray pyrolysis on Si(111) substrates preheated at 400 °C temperature and were studied as a function of neodymium (Nd)-doping concentration. X-ray diffraction (XRD) patterns confirmed that the deposited films possess hexagonal wurtzite ZnO structure. Further, it is observed that the doped films show a preferential orientation along the c-axis (0 0 2), which is perpendicular to the substrate. The un-doped films seem to be having a bit low-crystallinity, which is corroborated by the scanning electron microscope (SEM) analysis that showed nano-crystalline like features. Further, SEM analysis showed that the Nd doping triggers the formation bubble-like structure on top of the nano-crystalline structure. The SEM microstructures are interpreted with the Micro-Raman studies. Photoluminescence (PL) and XRD characterizations indicate that above 5 at.% doping concentrations, the Nd atoms preferentially agglomerate in the large islands.