Physical properties of sputtered amorphous Ge: The role of the deposition rate

The role of the deposition rate was studied on thin layers of amorphous germanium, prepared by cathode sputtering. Strong influence of this technological parameter on the density, electrical conductivity and optical absorption was found. The dependences observed are discussed in terms of the presence of voids, which influence the properties of a-Ge in their vicinity. The effect of argon and the traces of oxygen in argon is considered.We thank Dr. M. Rozsíval for testing our samples by the electron diffraction and Dr. B. Velický for his interest and helpful discussions.