Influence of duration time of CVD process on emissive properties of carbon nanotubes films

Abstract

In this paper various types of films made of carbon nanotubes (CNTs) are presented. These films were prepared on different substrates (Al 2 O 3 , Si n-type) by the two-step method. The two-step method consists of physical vapor deposition step, followed by chemical vapor deposition step (PVD/CVD). Parameters of PVD process were the same for all initial films, while the duration times of the second step -the CVD process, were different (15, 30 min.). Prepared films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and field emission (FE) measurements. The I-E and F-N characteristics of electron emission were discussed in terms of various forms of CNT films. The value of threshold electric field ranged from few V/µm (for CNT dispersed rarely on the surface of the film deposited on Si) up to ∼20 V/µm (for Al 2 O 3 substrate).

Studies of field emission process influence on changes in CNT films with different CNT superficial density

“…The field emitter is a carbon nanotube film (CNTs film) deposited on metallic substrate in two-step method PVD/CVD. The details of emitters preparation, properties and lamp construction were published in our previous papers [19][20][21][22]. The quality of the emitter, its stability, working time, efficiency are important factors for lighting properties of lamps with such emitters.…”