Granted Patent B2

US 12,640,329 · App. 18/484,797 · Granted May 26, 2026

Inventors: Michael Bachmann (Munich, DE); Simon Edler (Munich, DE); Andreas Schels (Wolnzach, DE); Florian Herdl (Oberaudorf, DE); Natalie Galfe (Munich, DE); Georg Düsberg (Taufkirchen, DE)

Assignee: KETEK GmbH Halbleiter- und Reinraumtechnik

H01J35/18H01J9/24H01J35/04H01J35/064H01J35/065

Abstract

Claims (27)

1 . An electron emission device comprising:

an electrically conductive base layer;

an intermediate layer directly on the base layer, wherein the intermediate layer is of a material having a band gap leading to a higher energy of a conduction band edge of the intermediate layer compared to the base layer; and

an electrically conductive gate layer directly on a side of the intermediate layer remote from the base layer,

wherein a breakdown voltage of the intermediate layer exceeds a work function of the gate layer divided by an elementary charge,

wherein the gate layer is a carbon layer of glassy carbon, and

wherein the electron emission device is configured to emit electrons through the gate layer upon applying a voltage between the base layer and the gate layer.

2 . The electron emission device according to claim 1 ,

wherein a thickness of the carbon layer is at least one monolayer and is at most 20 nm, and

wherein the band gap of the intermediate layer is at least 4 eV.

3 . The electron emission device according to claim 1 ,

wherein the glassy carbon is an amorphous material.

4 . The electron emission device according to claim 3 ,

wherein, seen in top view and by transmission electron microscopy, the carbon layer comprises filaments with a length-to-width ratio of at least 10.

5 . The electron emission device according to claim 1 ,

wherein the base layer is also of glassy carbon.

6 . The electron emission device according to claim 5 ,

wherein the intermediate layer is of hexagonal boron nitride.

7 . The electron emission device according to claim 1 ,

further comprising a first electric contact structure,

wherein the first electric contact structure comprises at least one of a grid structure or a bar structure extending across the gate layer and directly located at the gate layer,

wherein a thickness of the first electric contact structure exceeds a thickness of the carbon layer by at least a factor of 10 2 , and

wherein the first electric contact structure is also of glassy carbon.

8 . The electron emission device according to claim 1 ,

wherein the gate layer has a specific electric conductivity of at least 10 3 S/m.

9 . The electron emission device according to claim 1 ,

wherein the electron emission device is configured for a bending radius of 1 cm or less.

Assignments (1)

Continuity (1)

References Cited (16)