Abstract: The disclosure relates to a field emission cathode. The field emission cathode includes a microchannel plate, a cathode electrode and a number of cathode emitters. The microchannel plate is an insulative plate and includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The cathode electrode is located on the first surface. The number of cathode emitters are filled in the number of holes and electrically connected with the cathode electrode.

Abstract: An electron emission source includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked in that sequence, wherein an electron collection layer is sandwiched between the semiconductor layer and the insulating layer, the electron collection layer is in contact with the semiconductor layer and the insulating layer, and the electron collection layer is a conductive layer to collect electrons.

Abstract: An electron emission device includes a number of electron emission units spaced from each other, wherein each of the number of electron emission units includes a first electrode, a semiconductor layer, an electron collection layer, an insulating layer, and a second electrode stacked with each other, the electron collection layer is in contact with the semiconductor layer and the insulating layer, and the electron collection layer is a conductive layer.

Abstract: An electron emission device includes a number of electron emission units spaced from each other, wherein each of the number of electron emission units includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked with each other, the first electrode includes a carbon nanotube layer, a number of holes defines in the semiconductor layer, and a portion of the carbon nanotube layer suspended on the number of holes.

Abstract: An electron emission source includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked in that sequence, wherein the semiconductor layer defines a number of holes, the first electrode comprises a carbon nanotube layer, and a portion of the carbon nanotube layer corresponding to the number of holes is suspended on the number of holes.

Abstract: An electron emission device includes a number of electron emission units, wherein each of the number of electron emission units includes a first electrode, an insulating layer, and a second electrode stacked in that sequence, wherein the first electrode is a carbon nanotube composite structure having a carbon nanotube layer and a semiconductor layer stacked together, and the semiconductor layer is sandwiched between the carbon nanotube layer and the insulating layer, the first electrodes in the number of electron emission units are spaced apart from each other, and the second electrodes in the number of electron emission units are spaced apart from each other.

Abstract: An electron emission source includes a first electrode, an insulating layer, and a second electrode stacked in that sequence, wherein the first electrode is a carbon nanotube composite structure comprising a carbon nanotube layer and a semiconductor layer stacked together, and the semiconductor layer is sandwiched between the carbon nanotube layer and the insulating layer. A method for making the electron emission source is also related.

Abstract: An electron emission device includes a number of second electrodes intersected with a number of first electrodes to define a number of intersections. The first electrode includes a carbon nanotube layer and a semiconductor layer coated on the carbon nanotube layer. An insulating layer is sandwiched between the first electrode and the second electrode at each of the number of intersections, wherein the semiconductor layer is sandwiched between the insulating layer and the carbon nanotube layer.

Abstract: The disclosure relates to a method for making field emission cathode. A microchannel plate is provided. The microchannel plate includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The plurality of holes are filled with a carbon nanotube slurry. The carbon nanotube slurry is adhered on inner walls of the plurality of holes. The carbon nanotube slurry in the plurality of holes is solidified.

Abstract: An electron emission device includes a number of second electrodes intersected with a number of first electrodes to define a number of intersections. An electron emission unit is sandwiched between the first electrode and the second electrode at each of the number of intersections, wherein the electron emission unit includes a semiconductor layer, an electron collection layer, and an insulating layer stacked together, and the electron collection layer is a conductive layer.

Abstract: An electron emission device includes a number of first electrodes and a number of second electrodes intersected with each other to define a number of intersections. An electron emission unit is sandwiched between the first electrode and the second electrode at each of the number of intersections, wherein the electron emission unit includes a semiconductor layer and an insulating layer stacked together, the semiconductor layer defines a number of holes, the carbon nanotube layer covers the number of holes, and a portion of the carbon nanotube layer is suspended on the number of holes.

Abstract: The disclosure relates to a field emission cathode. The field emission cathode includes a microchannel plate, a cathode electrode and a number of cathode emitters. The microchannel plate is an insulative plate and includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The cathode electrode is located on the first surface. The number of cathode emitters are filled in the number of holes and electrically connected with the cathode electrode.

Abstract: The disclosure relates to a method for making field emission cathode. A microchannel plate is provided. The microchannel plate includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The plurality of holes are filled with a carbon nanotube slurry. The carbon nanotube slurry is adhered on inner walls of the plurality of holes. The carbon nanotube slurry in the plurality of holes is solidified.

Abstract: The disclosure relates to a field emission cathode. The field emission cathode includes a microchannel plate, a cathode electrode and a number of cathode emitters. The microchannel plate is an insulative plate and includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The cathode electrode is located on the first surface. The number of cathode emitters are filled in the number of holes and electrically connected with the cathode electrode.

Abstract: The disclosure relates to a field emission cathode. The field emission cathode includes a microchannel plate, a cathode electrode and a number of cathode emitters. The microchannel plate is an insulative plate and includes a first surface and a second surface opposite to the first surface. The microchannel plate defines a number of holes extending through the microchannel plate from the first surface to the second surface. The cathode electrode is located on the first surface. The number of cathode emitters are filled in the number of holes and electrically connected with the cathode electrode.

Abstract: An X-ray tube includes a vacuum tube. A field emission cathode structure and an anode spaced from each other are located in the vacuum tube. The field emission cathode structure includes a first metal plate, a second metal plate, and an electron emitter. The electron emitter is fixed between the first metal plate and the second metal plate. One end of the electron emitter extends out of the first metal plate and the second metal plate to act as an electron emission end.

Abstract: A field emission cathode device includes a cathode electrode. An electron emitter is electrically connected to the cathode electrode, wherein the electron emitter includes a number of sub-electron emitters. An electron extracting electrode is spaced from the cathode electrode by a dielectric layer, wherein the electron extracting electrode defines a through-hole. The distances between an end of each of the sub-electron emitters away from the cathode electrode and a sidewall of the through-hole are substantially equal.

Abstract: An electron emission device includes a number of electron emission units, wherein each of the number of electron emission units includes a first electrode, an insulating layer, and a second electrode stacked in that sequence, wherein the first electrode is a carbon nanotube composite structure having a carbon nanotube layer and a semiconductor layer stacked together, and the semiconductor layer is sandwiched between the carbon nanotube layer and the insulating layer, the first electrodes in the number of electron emission units are spaced apart from each other, and the second electrodes in the number of electron emission units are spaced apart from each other.

Abstract: An electron emission source includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked in that sequence, wherein an electron collection layer is sandwiched between the semiconductor layer and the insulating layer, the electron collection layer is in contact with the semiconductor layer and the insulating layer, and the electron collection layer is a conductive layer to collect electrons.

Abstract: An electron emission source includes a first electrode, a semiconductor layer, an insulating layer, and a second electrode stacked in that sequence, wherein the semiconductor layer defines a number of holes, the first electrode comprises a carbon nanotube layer, and a portion of the carbon nanotube layer corresponding to the number of holes is suspended on the number of holes.