High Current Emission from Patterned Aligned Carbon Nanotubes Fabricated by Plasma-Enhanced Chemical Vapor Deposition.

Linfan Cui,Bingjun Yang,Tifeng Jiao,Jiangtao Chen

doi:10.1186/s11671-015-1192-9

Linfan Cui, Bingjun Yang + Show 2 more

Open Access

https://doi.org/10.1186/s11671-015-1192-9

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Journal: Nanoscale research letters	Publication Date: Dec 1, 2015
Citations: 45	License type: CC BY 4.0

Abstract

Vertically, carbon nanotube (CNT) arrays were successfully fabricated on hexagon patterned Si substrates through radio frequency plasma-enhanced chemical vapor deposition using gas mixtures of acetylene (C2H2) and hydrogen (H2) with Fe/Al2O3 catalysts. The CNTs were found to be graphitized with multi-walled structures. Different H2/C2H2 gas flow rate ratio was used to investigate the effect on CNT growth, and the field emission properties were optimized. The CNT emitters exhibited excellent field emission performance (the turn-on and threshold fields were 2.1 and 2.4 V/μm, respectively). The largest emission current could reach 70 mA/cm2. The emission current was stable, and no obvious deterioration was observed during the long-term stability test of 50 h. The results were relevant for practical applications based on CNTs.

Highlights

Field emission is a quantum mechanical tunneling phenomenon
The emission densities and short emission lifetimes present obstacles for the practically available electron field emitters based on Carbon nanotube (CNT)
The results indicated that the fabrication of a single CNT was from a catalyst island

Summary

Background

Field emission is a quantum mechanical tunneling phenomenon. Electrons in the materials can emit into vacuum from solid surface which is determined by the strength of local electric field and potential barrier to emission. Aligned CNTs can be synthesized by chemical vapor deposition methods (CVD). The CVD methods are ideally suited to prepare CNT films on various substrates, and the process can be assisted by microwave of radio frequency plasma [19,20,21,22]. As CNTs are capable of emitting efficient high currents, they are potential as emitters in various devices [23, 24]. The CNT emitters were fabricated using radio frequency plasma-enhanced chemical vapor deposition (PECVD) method on patterned Si substrate. The vertically aligned CNT arrays showed good field emission properties with high emission current and ultra-long-term emission stability which were better than other reported patterned vertical CNTs [26,27,28]

Methods

Results and Discussion

Conclusions