Structure of nanometer line cold-cathode electron source array with grid and method for producing the same as well as application of flat panel display

[0054] Example

[0055] This embodiment presents the manufacturing process of the electron source array using copper oxide nanowires as the cold cathode material. For the specific manufacturing process steps, please refer to the attached Figure 7. First, the glass substrate was ultrasonically cleaned with acetone, ethanol, and deionized water for 20 minutes, dried with nitrogen, and then dried. On the glass substrate, the cathode electrode strips are prepared by the DC magnetron sputtering vacuum coating technology and the stripping process. The cathode electrode strip is composed of a chromium film and an aluminum film, the thickness of which is 120nm and 100nm, respectively. A plasma-enhanced vapor deposition method is used to prepare a silicon nitride and silicon dioxide composite insulating layer film, with a total thickness of 1.5 μm. The grid electrode strips are prepared by DC magnetron sputtering vacuum coating technology and stripping process. The gate electrode strip is composed of a chromium film and an aluminum film, with thicknesses of 400 nm and 100 nm, respectively. Reactive ion etching technology is used to etch the insulating layer film to form holes in the insulating layer. The transition layer film and the growth source film are prepared by DC magnetron sputtering vacuum coating technology and the stripping process. The transition layer film and the growth source film are made of chromium film and copper film, and their thicknesses are 100 nm and 1.0 μm, respectively. Finally, the glass substrate is put into a tube furnace for oxidation. The temperature is raised from room temperature to 400°C, then kept at 400°C for 3 hours, and finally cooled naturally. The entire oxidation process described above is carried out in air.

[0056] The prepared electron source array was observed by scanning electron microscope (SEM). Attached Picture 12 It is the electron micrograph of the electron source array observed by the scanning electron microscope (SEM). It can be found that the copper oxide nanowires are integrated in the gate structure to form a copper oxide nanowire electron source array. The diameter of the copper oxide nanowires is about 80 ~100nm, the height is 0.3~3.0μm.

[0057] The completed electron source array substrate and the anode phosphor screen substrate are assembled into a field emission display prototype device, and the two substrates are insulated by ceramic insulating materials. After the device is assembled, the entire device is tested under vacuum. First, apply a voltage on the anode electrode, and then apply a voltage between a certain row of grids and a certain column of cathodes or all of the cathode columns. Electrons will be emitted from the copper oxide nanowire cold cathode under the action of the anode voltage and the grid voltage. After being accelerated in a vacuum, it bombards the anode to emit light, so as to realize the display of a certain pixel or a certain row of pixels. Attached Figure 13 (a) is a display picture of a field emission display assembled from a copper oxide nanowire electron source array made by the present invention. The corresponding working conditions are: the anode working electric field is fixed at 5.2MV/m, and the grid working voltage is 40V, 80V, 100V, 120V, respectively. Figure 13 (b) is the relationship curve between anode collector current and grid voltage. It can be seen from the curve that when the anode electric field is fixed at 5.2 MV/m and the gate voltage increases from 0 V to 120 V, the current collected by the anode increases from 170 nA to 480 nA. Figure 14 (a) is a photo of the appearance of a fully packaged 3.5-inch copper oxide nanowire cold cathode field emission display manufactured by using the present invention. Figure 14 (b) is a photo of the device displaying characters and graphics. The above experimental results prove that the fabricated nanowire electron source array is promising for application in high-resolution, low-voltage field emission display devices.