J. García-Serrano, and U. Pal

Instituto de Física, Universidad Autónoma de Puebla, Apdo. Postal J-48, Puebla, Pue. 72570, Mexico.

The composite films of Si/ZnO were grown on quartz substrate by co-sputtering (r.f) of Si and ZnO targets. TEM images demonstrated a homogeneous distribution of clusters in the matrix with average size varied from 3.7 nm to 34 nm depending on the temperature of annealing of the films. IR absorption measurements revealed the bands correspond to the modes of vibrations of Si₃ in its triangular geometrical structure, SiO_x and ZnO. The evolution of the IR bands with the variation of Si content in the films and with the variation of the temperature of annealing are discussed in this work. The analysis of IR absorption and XPS spectra revealed the formation of nano-clusters in the composites, which consist of a Si₃ core and a SiO_x cap layer. With the increase of annealing temperature, the vibrational states of Si₃ changed from the triplet ³B₁(C_2n ) and ³A₂(D_3h) states to its singlet ground state ¹A₁(C_2n ) and the oxidation state of Si in SiO_x increased.