Optoelectronic array device having an upper transparent electrode

Patent metadata

Field	Value
Publication number	US-10957743-B2
Application number	US-201616065802-A
Country	US
Kind code	B2
Filing date	Dec 19, 2016
Priority date	Dec 23, 2015
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A matrix-array optoelectronic device includes a substrate on which a matrix array of what are called bottom electrodes is deposited; an active structure, which is preferably continuous and organic, arranged above the matrix-array of bottom electrodes, the structure being suitable for detecting light; and at least one what is called top electrode lying above the active structure, the top electrode being transparent to the light emitted or detected by the active structure; and at least one conductive element that is borne by the substrate without interposition of the active structure and that is connected to the top electrode by at least one vertical interconnection, the conductive element having an electrical conductivity greater than that of the top electrode. The device may also comprise a layer made of scintillator material, the layer being fastened to the top electrode, so as to form an x-ray imager.

First claim

The invention claimed is:

1. A matrix-array optoelectronic device comprising:
an electrically insulating substrate bearing, on one of its surfaces, a matrix array of bottom electrodes and a transistor connected to said bottom electrode;
an active structure arranged above said matrix-array of bottom electrodes, said active structure being configured to produce information according to a light detected and connected to said bottom electrode;
at least one top electrode lying above said active structure, said top electrode being transparent to the light emitted or detected by the active structure;
at least one conductive element that is borne by the substrate without interposition of said active structure between said at least one conductive element and the substrate and that is directly connected to said top electrode by at least one vertical interconnection, said conductive element having an electrical resistivity lower than that of said top electrode; and
a plurality of photosensitive pixels, each pixel comprising a photodiode formed by said active structure, said bottom electrode, and said top electrode, wherein said bottom electrode is connected to said at least one conductive element of the matrix-array optoelectronic device to read each pixel individually,
wherein said at least one vertical interconnection is formed from a material having a work function of value chosen so that an application, across the top electrode and at least the bottom electrodes that are closest to said vertical interconnection, of a potential difference that allows said active structure to detect said light, causes the appearance of a potential barrier that prevents the injection of parasitic electrical charge into said bottom electrodes through the active structure,
wherein said photodiode and said transistor forms a photodetector.

2. The matrix-array optoelectronic device as claimed in claim 1 , wherein said bottom electrodes define pixels of area no larger than 0.25 mm 2 .

3. The matrix-array optoelectronic device as claimed in claim 1 , wherein said vertical interconnection passes through said active structure.

4. The matrix-array optoelectronic device as claimed in claim 3 , wherein said or at least one said conductive element is arranged on a substrate region that is located interior to said matrix array of bottom electrodes.

5. The matrix-array optoelectronic device as claimed in claim 4 , also comprising a thin-film transistor that is electrically connected and adjacent to each said bottom electrode, said or at least one said conductive element being arranged above a said thin-film transistor, but without direct electrical connection with this transistor.

6. The matrix-array optoelectronic device as claimed in claim 4 , wherein said or at least one said conductive element is arranged in an aperture in a said lower electrode, said aperture having an area no larger than 10% of the area of the bottom electrode.

7. The matrix-array optoelectronic device as claimed in claim 4 , wherein said or at least one said conductive element replaces at least one said bottom electrode of the matrix array.

8. The matrix-array optoelectronic device as claimed in claim 4 , wherein said bottom electrodes are borne by a dielectric layer that is deposited on said substrate, whereas said or at least one said conductive element is arranged above said dielectric layer.

9. The matrix-array optoelectronic device as claimed in claim 3 , wherein said or at least one said conductive element is arranged on a peripheral region of the substrate, said region being located exterior to said matrix array of bottom electrodes.

10. The matrix-array optoelectronic device as claimed in claim 3 , wherein said or at least one said vertical interconnection has a larger lateral extent then the corresponding conductive element, so as to separate it from said active structure.

11. The matrix-array optoelectronic device as claimed in claim 3 , wherein, beyond said vertical interconnection, said or at least one said conductive element is covered with a dielectric layer, so as to separate it from said active structure.

12. The matrix-array optoelectronic device as claimed in claim 3 , wherein said or at least one said conductive element is formed from a material having a work function of value chosen to cause the appearance of a potential barrier with said active structure when said potential difference is applied across the top electrode and said bottom electrodes.

13. The matrix-array optoelectronic device as claimed in claim 1 , wherein said at least one conductive element is arranged on a peripheral region of the substrate, said region being located exterior to said matrix array of bottom electrodes, which is not covered by said active structure, and forms a bus that borders at least one edge, and preferably two contiguous edges, of said matrix array.

14. The matrix-array optoelectronic device as claimed in claim 13 , wherein a plurality of said at least one conductive elements at least partially encircle said matrix array of bottom electrodes.

15. The matrix-array optoelectronic device as claimed in claim 13 , wherein said one or more said at least one vertical interconnections and said bus are dimensioned such that the electrical resistance between said bus and said top electrode is lower than or equal to 20 Ohms.

16. The matrix-array optoelectronic device as claimed in claim 1 , comprising a plurality of said at least one conductive elements connected together by a bus.

17. The matrix-array optoelectronic device as claimed in claim 1 , wherein said active structure extends continuously above said matrix array of bottom electrodes and comprises at least one layer containing at least one organic material.

18. The matrix-array optoelectronic device as claimed in claim 17 , wherein said top electrode is based on PEDOT.

19. The matrix-array optoelectronic device as claimed in claim 1 , wherein said or at least one said vertical interconnection is made of the same material as the top electrode.

20. The matrix-array optoelectronic device as claimed in claim 1 , wherein said active structure is a photoconverting structure that interacts with said top and bottom electrodes to form a photodiode device and to thus create a matrix array of photodetectors.

21. The matrix-array optoelectronic device as claimed in claim 20 , also comprising a layer made of scintillator material, said layer being fastened above said top electrode, so as to form an x-ray imager.

Assignees

• Commissariat Energie Atomique
• Isorg
• Trixell

Inventors

• Benwadih Mohammed
• Verilhac Jean-Marie
• Charlot Simon
• Joimel Jérôme
• Rohr Pierre

Classifications

• H10F39/811 Primary

  Interconnections · CPC title

• Y02E10/549

  Organic PV cells · CPC title

• H10K30/83

  comprising arrangements for extracting the current from the cell, e.g. metal finger grid systems to reduce the serial resistance of transparent electrodes · CPC title

• H10K65/00

  Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element and at least one organic radiation-sensitive element, e.g. organic opto-couplers (organic image sensors integrated with organic light-emitting devices H10K39/34; OLED displays integrated with photosensors H10K59/13) · CPC title

• H10K39/36 Primary

  Devices specially adapted for detecting X-ray radiation · CPC title