Electrical and optical properties of plasma-deposited amorphous carbon filmsFunded under: JRC-ADVMAT 1C
Semiconducting amorphous hydrocarbon layers (a-C:H) were prepared by plasma-assisted chemical vapour deposition (PACVD). The addition of nitrogen led to significant changes in their electrical and optical properties. Since only a small fraction of the gas phase nitrogen is finally incorporated into the hydrocarbon film, a large excess of N(2) over acetylene had to be used. The consequence was a change of the plasma parameters and thus also of the film growth conditions. To separate the influence of the changed deposition conditions from that of the N(2) incorporated, some of the undoped samples were subsequently modified by ion implantation of nitrogen. However, here also the possible structural changes in the film caused by the impact energy of ions had to be considered. The films were investigated by optical spectroscopy, thermopower, electrical and photoconductivity measurements. For undoped and nitrogen-containing films, the results of temperature dependent conductivity measurements yielded information on the conduction mechanism. From optical absorption spectra, changes in the band gap energy were estimated. With increasing nitrogen content E(g) was reduced for ion-implanted as well as for gas-phase doped layers.
Bibliographic Reference: Paper presented: 12th European Conference on Diamond and Diamond-like Carbon Coatings, Nice (FR), Sept. 2-6, 1991
Availability: Available from (1) as Paper EN 36281 ORA
Record Number: 199111234 / Last updated on: 1994-12-02
Original language: en
Available languages: en