US 12,243,738 B2
Methods for forming a field emission cathode
Cheng Qian, Cary, NC (US)
Assigned to NCX Corporation, Raleigh, NC (US)
Filed by NCX Corporation, Raleigh, NC (US)
Filed on Feb. 12, 2024, as Appl. No. 18/439,285.
Application 18/439,285 is a continuation of application No. 18/252,992, granted, now 11,929,249, previously published as PCT/IB2021/060611, filed on Nov. 16, 2021.
Claims priority of provisional application 63/114,774, filed on Nov. 17, 2020.
Prior Publication US 2025/0006448 A1, Jan. 2, 2025
Int. Cl. H01J 9/02 (2006.01)
CPC H01J 9/025 (2013.01) 29 Claims
OG exemplary drawing
 
1. A method of forming a field emission cathode, comprising:
mixing a plurality of carbon nanotubes and a solution at a particular ratio to form a base mixture, the solution comprising a water stable conducting polymer in a liquid medium;
exposing the base mixture to a first ultrasonic dispersion process;
introducing a metal oxide sol solution to the base mixture to form a field emission material precursor;
exposing the field emission material precursor to a second ultrasonic dispersion process to form a stable solution of the field emission material precursor;
introducing a polar additive into the stable solution of the field emission material precursor to form a final sol solution as a final field emission material precursor;
depositing a layer of the final field emission material precursor on at least a portion of a substrate;
drying the layer of the final field emission material precursor and the substrate such that the layer of the final field emission material precursor forms a uniform gel layer on the substrate;
annealing the gel layer and the substrate such that the gel layer forms a field emission material; and
activating the field emission material to form the field emission cathode.