Characterization and Properties of Ge1-x-Cx:H Compounds Obtained by X-ray CVD of Germane/Ethyne Systems: Effect of the Irradiation Dose

Amorphous germanium carbides have been prepared by X‐ray activated CVD from germane/ethyne systems containing from 10 % to 80 % of ethyne. The effects of the dosage on the composition, characteristics, and properties of the solids obtained have been investigated. The composition of the material is found to change depending on both the ethyne percentage in the mixture and the irradiation time. Electron paramagnetic resonance (EPR), X‐ray diffraction (XRD) analysis, and infrared spectroscopy (IRS) results indicate that the solids are formed by a randomly bound network of carbon and germanium atoms with hydrogen atoms terminating all the dangling bonds. Optical gap values higher than 3.0 eV, and increasing with the carbon molar fraction of the solid, have been found. Hydrogenated germanium‐carbon alloys have been obtained from X‐ray radiolysis of GeH4/C2H2 systems. Their morphology, bonding, structure, and optical properties have been investigated as a function of the irradiation time. The solids are formed by a randomly bound network of carbon and germanium atoms with hydrogen atoms terminating all the dangling bonds (see Figure).