U. Pal et J. Garcia-serrano, Infrared absorption and evidence of Si-3 nanocluster formation in Si/ZnO composites, SOL ST COMM, 111(8), 1999, pp. 427-430
Si nanoclusters embedded in ZnO matrix were prepared by radio-frequency co-
sputtering and subsequent annealing of the composite films. Transmission el
ectron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and infrare
d (IR) spectroscopy techniques were used to characterize the composite film
s. The average size of the nanoclusters, depending on annealing temperature
varied from 3.7 to 34 nm. The nanoclusters in the composites consist of a
Si core surrounded by a SiOx cap layer. The Si-3 in the clusters remain mai
nly in its triangular geometrical structure. With the increase of annealing
temperature, the vibrational state of Si-3 changes from its excited B-3(1)
(C-2v) and (3)A(2)'(D-3h) triplet states to (1)A(1)(C-2v) Singlet ground st
ate and the oxidation state of Si in SiOx cap layer increases. (C) 1999 Els
evier Science Ltd. All rights reserved.