High voltage thin film optical switch

Patent metadata

Field	Value
Publication number	US-9946135-B2
Application number	US-201514725443-A
Country	US
Kind code	B2
Filing date	May 29, 2015
Priority date	May 29, 2015
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A thin film optical switch includes a layer of photosensitive material that extends laterally with first and second electrodes are spaced apart laterally from one another along the layer of photo sensitive material. The first and second electrodes contact the photo sensitive material at first and second junctions, respectively. At least one field plate is electrically insulated from the photo sensitive material and extends laterally along the layer of photo sensitive material over the first or the second junction. The field plate is electrically connected to the first electrode or the second electrode.

First claim

What is claimed is:

1. A device comprising:
a thin film optical switch comprising:
a layer of photo sensitive material that extends laterally;
first and second electrodes spaced apart laterally from one another along the layer of photo sensitive material, the first and second electrodes contacting the photo sensitive material at first and second junctions, respectively;
at least one insulator layer extending laterally along the layer of photo sensitive material and the first and second electrodes; and
at least one field plate extending laterally along the layer of photo sensitive material over the first or the second junction, the at least one field plate spaced apart from the layer of photo sensitive material by the at least one insulator layer, wherein the at least one field plate is electrically connected to the first electrode or the second electrode via a short through the at least one insulator layer.

2. The device of claim 1 , wherein the at least one field plate comprises:
a first field plate extending laterally along the layer of photo sensitive material over the first junction, the first field plate spaced apart from the layer of photo sensitive material by the at least one insulator layer, wherein the first field plate is shorted to the first electrode through the at least one insulator layer; and
a second field plate extending laterally along the layer of photo sensitive material over the second junction, the second field plate spaced apart from the layer of photo sensitive material by the at least one insulator layer, wherein the second field plate is shorted to the second electrode.

3. The device of claim 1 , wherein the optical switch comprises semiconductor, insulator and conductive layers formed on a nonconductive substrate.

4. The device of claim 1 , wherein the optical switch includes p+/i/p+, p+/n−/p, or n+/p−/n+ regions that are laterally spaced.

5. The device of claim 1 , wherein the photo sensitive material comprises a-Si:H.

6. The device of claim 1 , wherein the field plate extends laterally by at least a width larger than a separation between the field plate and the photosensitive material.

7. The device of claim 1 , wherein a dark state leakage current of the optical switch is less than about 1×10 −12 amperes at +/−100 V between the first and second electrodes.

8. The device of claim 1 , wherein the at least one field plate comprises a transparent conductor.

9. The device of claim 1 , wherein one or both of the first and second electrodes comprise a transparent conductor.

10. The device of claim 8 , wherein the transparent conductor is indium tin oxide (ITO).

11. The device of claim 1 , wherein the at least one field plate comprises MoCr or alloys thereof.

12. The device of claim 1 , wherein the at least one field plate is a metal.

13. The device of claim 1 , wherein the at least one field plate is an n+ or p+ doped material.

14. The device of claim 1 , wherein at least one of the first and second electrodes is a metal.

15. The device of claim 1 , wherein at least one of the first and second electrodes is an n+ or p+ doped material.

16. The device of claim 1 , wherein at least one of the first and second electrodes comprises the same material as the at least one field plate.

17. The device of claim 1 , wherein the ratio of on current to off current of the optical switch is greater than about 500 at an illumination of about 7×10 13 photons/second.

18. The device of claim 1 , wherein the layer of photo sensitive material is substantially planar.

19. The device of claim 1 , wherein the layer of photo sensitive material conformally coats a substructure.

20. A thin film optical switch comprising:
a non-conducting substrate having a first surface and an opposing second surface;
a layer of photo sensitive material disposed over a first surface of the substrate;
a first electrode in contact with the photo sensitive material at a first junction;
a second electrode in contact with the photo sensitive material at a second junction, the second electrode spaced apart laterally from the first electrode;
a field plate spaced apart from the layer of photo sensitive material, the field plate disposed over the second surface of the substrate, the field plate extending laterally under the first junction and electrically connected to the first electrode via a short through the non-conducting substrate, wherein the non-conducting substrate is disposed between the at least one field plate and the layer of photo sensitive material.

21. A thin film optical switch, comprising:
a layer of photo sensitive material;
a first electrode and a second electrode spaced apart laterally from one another along the layer of photo sensitive material, the first and second electrodes in contact with the photo sensitive material at a first junction and a second junction, respectively;
at least one insulator layer extending laterally along the layer of photo sensitive material and the first and second electrodes;
a first field plate electrically connected to the first electrode via a first short through the at least one insulator layer, the first field plate extending laterally over the first junction, the first field plate spaced apart from the layer of photo sensitive material by the at least one insulator layer; and
a second field plate electrically connected to the second electrode via a second short through the at least one insulator layer, the second field plate extending laterally over the second junction, the second field plate spaced apart from the layer of photo sensitive material by the at least one insulator layer.

Assignees

• Palo Alto Res Ct Inc

Inventors

• Lu Jengping
• Biegelsen David K

Classifications

• G09G2310/066

  Waveforms comprising a gently increasing or decreasing portion, e.g. ramp · CPC title

• G09G2300/0842

  forming a memory circuit, e.g. a dynamic memory with one capacitor · CPC title

• H01L31/10

  Electricity · mapped topic

• G09G3/3233

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G09G3/025 Primary

  with scanning or deflecting the beams in two directions or dimensions · CPC title