Patent ID: 7988515

Claim:
A method for manufacturing a field emission electron source comprising: providing a CNT array; drawing a bundle of CNTs from the CNT array to form a CNT yarn; soaking the CNT yarn into an organic solvent, and shrinking the CNT yarn into a CNT string after the organic solvent volatilizing; applying a voltage between two opposite ends of the CNT string, until the CNT string snaps at a certain point to form two CNT string emitters, wherein each of the two CNT string emitters comprises an end portion and a break-end portion opposite to the end portion, the break-end portion comprises a plurality of CNT bundles, each of the plurality of CNT bundles has a taper shaped end comprising a plurality of CNTs, and some CNTs protrude higher than other adjacent CNTs; and attaching the end portion of at least one of the two CNT string emitters to a conductive base.