Effects of nitrogen doping on the electrical conductivity and optical absorption of ultrananocrystalline diamond/hydrogenated amorphous carbon films prepared by coaxial arc plasma deposition
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-06-07 |
| Journal | Japanese Journal of Applied Physics |
| Authors | Abdelrahman Zkria, YÅ«ki Katamune, Tsuyoshi Yoshitake |
| Institutions | Kyushu Institute of Technology, Aswan University |
| Citations | 13 |
Abstract
Section titled āAbstractāAbstract 3 at. % nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were synthesized by coaxial arc plasma deposition. Optically, the films possess large absorption coefficients of more than 10 5 cm ā1 at photon energies from 3 to 5 eV. The optical band gap was estimated to be 1.28 eV. This value is smaller than that of undoped films, which might be attributable to increased sp 2 fractions. The temperature dependence of the electrical conductivity implies that carrier transport follows a hopping conduction model. Heterojunctions with p-type Si substrates exhibited a typical rectifying action. From the capacitance-voltage characteristics that evidently indicated the expansion of a depletion region into the film side, the built-in potential and carrier concentration were estimated to be 0.51 eV and 7.5 Ć 10 16 cm ā3 , respectively. It was experimentally demonstrated that nitrogen-doped UNCD/a-C:H films are applicable as an n-type semiconductor.