Nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films prepared by pulsed laser deposition

Nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were deposited by pulsed laser deposition. The film doped with a nitrogen content of 7.9 at.% possessed n-type conduction with an electrical conductivity of 18^-1.cm^-1 at 300 K. A heterojunction with p-type Si exhibited typical rectifying action. The UNCD grain size was estimated to be 2.5nm from X-ray diffraction measurement. Near-edge X-ray absorption fine-structure and Fourier transform infrared spectroscopies revealed the preferential formations of C=N and C-N bonds and an enhanced amount of sp² bonds in the films.