Effect of film structure on field emission properties of nitrogen doped hydrogenated amorphous carbon films

In this study, we investigated the effect of bonding structure of nitrogen doped a-C:H (a-C:N:H) film on the electrical and field emission properties. The bonding structure in nitrogen doped a-C: H films were controlled via growth using an acetonitrile methane mixture. Nitrogen atoms in the a-C:N:H films were incorporated in termination structure such as C N and N-H. Current-voltage measurements for a-C:N:H films showed that the electrical conductivity was high for the lightly nitrogen doped films. The lightly doped a-C:N:H film exhibited lower threshold field emission voltage than heavy nitrogen doped films. The behavior observed in this research suggests that nitrogen atoms do not act as electron donors. The results can be interpreted as that incorporated nitrogen atoms do not acts as electron donor because they are involved in the C N and N-H termination structures. Characterizations of the doping system, not only doping species. is necessary to design the electronic structures of a film to obtain high efficiency field emission. (C) 2008 Elsevier B.V. All rights reserved.