Thursday, August 28, 2008

Low Work Function Material

United States Patent Application 20080206448
Kind Code A1
Mao; Dongsheng ; et al. August 28, 2008

Low Work Function Material


The present invention is directed toward methods for incorporating low work function metals and salts of such metals into carbon nanotubes for use as field emitting materials. The present invention is also directed toward field emission devices, and associated components, comprising treated carbon nanotubes that have, incorporated into them, low work function metals and/or metal salts, and methods for making same. The treatments of the carbon nanotubes with the low work function metals and/or metal salts serve to improve their field emission properties relative to untreated carbon nanotubes when employed as a cathode material in field emission devices.

Inventors: Mao; Dongsheng; (Austin, TX) ; Yaniv; Zvi; (Austin, TX) ; Fink; Richard Lee; (Austin, TX) ; Pavlovsky; Igor; (Austin, TX)
Correspondence Name and Address:
P.O BOX 1022
Assignee Name and Adress: Nano-Proprietary, Inc.

Serial No.: 028171
Series Code: 12
Filed: February 8, 2008

U.S. Current Class: 427/77; 427/443.2; 977/742; 977/750; 977/752; 977/847
U.S. Class at Publication: 427/77; 427/443.2; 977/742; 977/750; 977/752; 977/847
Intern'l Class: B05D 5/12 20060101 B05D005/12


1. A method comprising the steps of :a) dispersing carbon nanotubes in a metal salt solution comprising a solvent; and b) removing the solvent to yield metal salt-treated carbon nanotubes.

[0079]It can be seen from FIG. 12 that the Cs salt-treated CNTs have significantly better field emission properties than untreated CNTs. A threshold field of less than 0.9 V/.mu.m and emission current of 30 mA at 1.84 V/.mu.m was achieved for the Cs salt-treated CNTs, whereas the untreated CNTs exhibited a threshold field of about 1.3 V/.mu.m and required a field of approximately 2.80 V/.mu.m to generate an emission current of 30 mA.