Structural, chemical, optical and electronic properties of thin amorphous hydrogenated germanium/carbon films, produced from tetramethylgermanium by means of a radio frequency plasma enhanced chemical vapour deposition process, are described. The study reveals good quality of both the films themselves and the film/silicon interface. Strong dependence of chemical, optical and electronic properties on the RF power applied during deposition process makes the investigated materials promising candidates for applications in the field of multilayer optoelectronic systems. Substantial differences of refractive index (for the wavelength of 400 nm ranging from 1.68 to 3.35, depending on the RF power) suggest such a use as materials for interference multistate optical memories, for instance. (C) 2003 Elsevier Science B.V. All rights reserved.