Cluster Assembled Sb Films: Studies On Structure, Surface And Optical Properties

Abstract

A low energy cluster beam deposition (LECBD) technique has been used to prepare the Sb cluster films on different substrates and are characterized using a variety of probes. Proton induced X-ray emission (PIXE) analysis shows the absence of any foreign trace elemental impurity even at ppm level. Glancing angle X-ray diffraction (GXRD) and transmission electron diffraction (TED) studies reveal the presence of single crystalline feature of Sb with hexagonal symmetry along with Sb-oxides. The transmission electron micrograph (TEM) of the cluster films of thickness 20 Å and 100 Å show size distribution which is more for the 100 Å film compared to that of the 20 Å one. The photoluminescence (PL) studies at 300 K show red shifted peaks along with the one possibly due to HOMO-LUMO transition around 2.4 eV. X-ray photoelectron spectroscopy (XPS) of Sb cluster films show shoulders to the core level peaks of the Sb corresponding to 3d 3=2 and 3d 5=2 which are shifted by 1.0 to 2.0 eV suggesting the formation of Sb-oxide. Raman scattering studies show the shift of A 1g and E g vibrational modes from their bulk value.