AVS 45th International Symposium
    Surface Science Division Thursday Sessions
       Session SS-ThP

Paper SS-ThP32
Scanning Tunneling Spectroscopy and X-ray Photoemission Spectroscopy Studies of Thin Films of WO3 and In2O3

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Surface Science Division Poster Session
Presenter: S. Santucci, Università dell'Aquila, Italy
Authors: S. Santucci, Università dell'Aquila, Italy
L. Lozzi, Università dell'Aquila, Italy
L. Odorisio, Università dell'Aquila, Italy
M. Passacantando, Università dell'Aquila, Italy
C. Cantalini, Università dell'Aquila, Italy
Correspondent: Click to Email
p-n junction between p-Si and n-type semiconductor oxides like WO3 and In2O3 have been fabricated by thermal evaporation in high vacuum of pure powders onto p-doped Si(100) and submitted to anneal at different temperatures up to 450°C at different times. The rectifying properties of the films have been studied by using the Scanning Tunneling Spectroscopy (STS) technique in air and using Cr-Au contacts on the etched surface of silicon and on the deposited films respectively. I-V characteristics have been measured for the films in the presence of NOx gas carried in a flux of dry air. The surface morphology of the deposited films with different annealing temperatures have been studied by Atomic Force Microscopy (AFM) where we have observed a regular rearrangement of the surface with a globular aspect for the In2O3 deposits whereas for WO3 films it showed a more flat and regular surface. X-ray Photoelectron spectroscopy (XPS) has been employed to study the composition of the deposited films and an ion beam depth profile technique to study the interface formation with the silicon substrate. n-type behavior of the films which is due to the oxygen deficiency has been observed by studying the valence band spectra of the films. A comparison with the Density Of States obtained by calculating the (dI/dV)/(I/V) of the I(V) curves detected by the STS technique has been also performed.