Optically activated transistor, switch, and photodiode

Patent metadata

Field	Value
Publication number	US-10700226-B2
Application number	US-201815990067-A
Country	US
Kind code	B2
Filing date	May 25, 2018
Priority date	May 25, 2017
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

An optically activated device that includes an active material on a substrate with two electrodes electrically connected to the active material, the active material conducts current in the presence of light and does not conduct appreciable current in the absence of light. The optically activated device functions as a photodiode, a switch, and an optically gated transistor. The optically activated device conducts current in the presences of light. The active material may be layers of germanium selenide and germanium selenide and an element. Germanium selenide may be sputtered onto a substrate to create layers of material separated by layers of co-sputtered germanium selenide with the element. The active material may be deposited onto a flexible substrate.

First claim

What is claimed is:

1. An optically activated device comprising:
an active material on a substrate;
a first electrode electrically connected to the active material; and
a second electrode electrically connected to the active material, wherein the active material conducts current bidirectionally in the presence of light and wherein the active material does not conduct appreciable current in the absence of light, wherein the optically active device exhibits a current-voltage curve with operating regions that include at least a linear region and a saturation region.

2. The optically activated device of claim 1 , wherein an amount of current conducted by the active material is dependent on an intensity of the light.

3. The optically activated device of claim 2 , wherein the optically activate device comprises no more than two electrodes in contact with the active material.

4. The optically activated device of claim 3 , wherein the two electrodes are spaced between 1 micrometer and 10 millimeters apart on a surface of the active material.

5. The optically activated device of claim 1 , wherein the active material comprises:
a layer comprising germanium selenide (GeSe).

6. The optically activated device of claim 1 , wherein the active material comprises:
a first layer comprising germanium selenide (GeSe); and
a second layer comprising germanium GeSe and an element.

7. The optically activated device of claim 1 , wherein the active material comprises:
a first layer comprising germanium selenide (GeSe);
a second layer comprising GeSe and an element;
a third layer comprising GeSe, wherein the second layer is positioned between the first layer and the third layer;
a fourth layer comprising GeSe and the element, wherein the third layer is positioned between the second layer and the fourth layer; and
a fifth layer comprising GeSe, wherein the fourth layer is positioned between the third layer and the fifth layer.

8. The optically activated device of claim 7 , the first layer having a thickness of approximately 100 angstroms, the second layer having a thickness of approximately 10 angstroms to 30 angstroms, the third layer having a thickness of approximately 100 angstroms, the fourth layer having a thickness of approximately 10 angstroms to 30 angstroms, and the fifth layer having a thickness of approximately 100 angstroms.

9. The optically activated device of claim 7 , wherein the GeSe further comprises Ge 2 Se 3 .

10. The optically activated device of claim 7 , wherein the element comprises tin (Sn), aluminum (Al), carbon (C), Chromium (Cr), Tungsten (W), Titanium (Ti), or copper (Cu).

11. The optically activated device of claim 1 , wherein the active material is flexible.

12. The optically activated device of claim 1 , wherein the substrate includes a p-type silicon substrate.

13. A method of providing an optically activated device comprising:
forming a first layer by depositing germanium selenide (GeSe) onto a substrate;
forming a second layer by depositing GeSe and an element onto the first layer, wherein forming the second layer further comprises co-sputtering the GeSe and the element, the second layer having a thickness of approximately 10 to 30 angstroms;
forming a third layer by depositing GeSe onto the second layer;
forming a fourth layer by depositing GeSe and the element onto the fourth third layer; and
forming a fifth layer by depositing GeSe onto the fourth layer.

14. The method of claim 13 , electrically connecting only two terminals to the fifth layer of the optically activated device.

15. The method of claim 13 , wherein forming the first layer further comprises sputtering the GeSe, the first layer having a thickness of approximately 100 angstroms.

16. The method of claim 13 , wherein forming the third layer further comprises sputtering the GeSe, the third layer having a thickness of approximately 100 angstroms.

17. The method of claim 13 , wherein forming the fourth layer further comprises co-sputtering GeSe and the element, the fourth layer having a thickness of approximately 10 to 30 angstroms.

18. The method of claim 13 , wherein forming the fifth layer further comprises sputtering the GeSe, the fifth layer having a thickness of approximately 100 angstroms.

19. An optically activated device comprising:
a p-type silicon substrate comprising a native oxide layer;
a first layer comprising germanium selenide (GeSe) deposited on the p-type silicon substrate;
a second layer comprising GeSe and an element deposited on the first layer;
a third layer comprising GeSe deposited on the second layer;
a fourth layer comprising GeSe and the element deposited on the third layer;
a fifth layer comprising GeSe deposited on the fourth layer;
a first electrode in contact with the fifth layer; and
a second electrode in contact with the fifth layer, wherein the combination of the substrate, the first layer, the second layer, the third layer, the fourth layer, and the fifth layer conducts current between the first electrode and the second electrode in the presence of light and does not conduct appreciable current in the absence of light, and wherein no more than two electrodes are in contact with the fifth layer, wherein the optically active device exhibits a current-voltage curve with operating regions that include at least a linear region and a saturation region.

Assignees

• Univ Boise State

Inventors

• Campbell Kristy A

Classifications

• H10F77/206

  for devices having potential barriers · CPC title

• H10F77/12

  Active materials · CPC title

• H10F30/222

  the potential barrier being a PN heterojunction · CPC title

• H10F77/127 Primary

  comprising only Group IV-VI or only Group II-IV-VI chalcogenide materials, e.g. PbSnTe · CPC title

• C23C14/0629

  of zinc, cadmium or mercury · CPC title