Double-gated isolated vertically aligned carbon nanofiber field emission and field ionization arrays

Electron impact ionization (ElI) is used extensively in mass spectrometry for gas-phase analytes. Due to the significant amount of fragmentation generated by ElI, the spectrum is usually very noisy. In addition, the thermionic emission electron source used in ElI has a slow response time and consumes large amount of power. To address these two issues, double-gated vertically aligned carbon nanofiber (VACNF) field emission and field ionization arrays have been developed. These arrays were characterized as field ionizers, which could produce molecular ions without severe fragmentation; and as field emitters, which act as an electron source with a fast response time and consume less power than using thermionic emission. Self-aligned double-gated isolated VACNF arrays, which were fabricated using a photoresist-based planarization process, are reported. These arrays were designed such that the tip electric field is maximized and the shielding effect from the neighboring tips is minimized while the device is capable of handling large voltages during field emission and field ionization. Two types of arrays were fabricated: (1) CNFs with tips in-plane with the gate and (2) CNFs with tips 0.9tm below the gate.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Chen, Liang-Yu, 1979-

Advisor dc:contributor.advisor

• Akintunde Ibitayo (Tayo) Akinwande.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/40492

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40492