Synthesis of Nano-Structured Sb₂Te₃ Thin Films by Stacked Elemental Layer Method

Nanostructured Sb₂Te₃ thin films were synthesized by stacking the elemental layer which is allowed to isochronal annealing at various temperatures in the presence of Ar atmosphere. X-ray Diffraction (XRD) results confirm the presence of dominated (015) and (107) oriented hexagonal phase at above 350 °C. The crystallite size of about 58 nm of the annealed film was calculated from the XRD spectra. The XRD result shows the growth of H (105) oriented Sb₂Te₃ thin films at this temperature region. The transmission spectra indicate good optical behavior of the annealed stack. The observed bandgap was between 2 and 2.5 eV. The resistivity of the annealed stack reveals the semiconductor behavior and also low resistance. Field Emission Scanning Electron Microscope (FESEM) images show that the deposit was composed of nano pillar like structure with the size of about 70 nm and uniform film thickness. Atomic Force Microscope (AFM) images also depicted the presence of nano size particles in Sb₂Te₃ thin film and uniform surface morphology with roughness of about 38 nm. The particle size of about 60 nm could also be observed from AFM analysis. From the observed results, it is suggested that the synthesis of nano structured Sb₂Te₃ thin film could be produced by using the Stacked Elemental Layer (SEL) method.