AVS 49th International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeP

Paper TF-WeP5
XPS Study of First Stages of ZnO Growth and Nano-structure Dependence of the Polarisation Effects at ZnO/SiO@sub 2@ and ZnO/Al@sub 2@O@sub 3@ Interfaces

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Poster Session
Presenter: A.I. Martin-Concepcion, CSIC-Univ. Sevilla, Spain
Authors: A.I. Martin-Concepcion, CSIC-Univ. Sevilla, Spain
F. Yubero, CSIC-Univ. Sevilla, Spain
J.P. Espinos, CSIC-Univ. Sevilla, Spain
A.R. Gonzalez-Elipe, CSIC-Univ. Sevilla, Spain
S. Tougaard, University of Southern Denmark
Correspondent: Click to Email
A critical characteristic of nanoparticles and, in general, nanomaterials, is the overweighing importance of the surface and interface layers in respect to the bulk because of the small size of the aggregates (in 3D) or thickness of the layers (in the case of 2D) that constitute the nanomaterial. The present paper reports about the characterization of these interface layers in the particular case of ZnO/MO (MO: Al@sub 2@O@sub 3@ and SiO@sub 2@) interfaces by using X-ray photoelectron spectroscopy (XPS). Careful experiments have been performed consisting in the deposition of ZnO material on SiO@sub 2@ and Al@sub 2@O@sub 3@ substrates. Several samples were produced and characterized in situ. The nanostructure of the first stages of growth of the ZnO deposited was determined by Tougaard -peak shape analysis of several photoelectron peaks from both substrate and overlayer to check the consistency of the determined growth mechanisms. Thus the actual nanostructure of the growing ZnO films were carefully determined. In addition, the chemical interaction at the ZnO/MO interface was monitored by following the variation of the Auger parameter of the Zn atoms, as the amount of ZnO deposited was increased. Thus, the changes of the Auger parameter of the ZnO atoms have been correlated with the actual nanostructures formed by the ZnO deposits. From this information, a model is presented that accounts for the changes in the electronic parameters determined by XPS as a result of bonding and polarization interactions at the interface.