ИСТИНА

The nanocarbon films were produced by plasma-enhanced chemical vapor deposition (PE CVD) from hydrogen-methane gas mixture activated by a direct current discharge. With scanning electron microscopy investigation composition of the films of few-layer graphene flakes and carbon nanoscrolls homogeneously distributed over whole film surface was revealed. Variation of structural characteristics such as dimensions and density of the nanographite flakes and nanoscrolls was made by changing substrate temperature and methane concentration during deposition process. Comparative study of the field electron emission characteristics of the films obtained with different deposition parameters was performed in a flat diode configuration. It was found that the density of the emission sites and average field enhancement factor are not correlated with the substrate temperature varied in the range of 840 – 1000 °C during CVD. At the same time, with increasing the volume fraction of methane, the field enhancement factor increased on average by 30%. The films with the best field emission characteristics were investigated by scanning anode field emission microscopy in order to explore the emission properties of individual emission sites and their degradation with time. The possible mechanisms responsible for the observed field emission behavior are discussed on basis of comparison of the structural properties of the nanocarbon emitters before and after field emission measurements.