EP3811428A1

EP3811428A1 - Optoelectronic device and process for manufacturing same

Info

Publication number: EP3811428A1
Application number: EP19742841.0A
Authority: EP
Inventors: Benjamin BOUTHINON; Pierre Muller; David GUILLERMARD
Original assignee: Isorg SA
Current assignee: Isorg SA
Priority date: 2018-06-04
Filing date: 2019-06-03
Publication date: 2021-04-28
Also published as: JP2021527319A; FR3082055B1; KR20210035097A; WO2019234339A1; US20210167324A1; FR3082055A1; CN112262485A

Abstract

The invention relates to an optoelectronic device comprising a substrate, a matrix array (70) of optoelectronic components covering the substrate, first conductive tracks connected to the optoelectronic components, an adhesive layer covering one portion of the matrix array and a coating (44) making contact with the adhesive layer, the coating comprising a perimeter, the device furthermore comprising a second track (72) that reflects radiation at a wavelength comprised between 335 nm and 10.6 ym and that extends, in alignment with the perimeter, in a given direction between the first conductive tracks and the coating.

Description

OPTOELECTRONIC DEVICE AND METHOD FOR MANUFACTURING THE SAME

The present patent application claims the priority of the French patent application FR18 / 00561 which will be considered as an integral part of the present description.

Field

The present description generally relates to optoelectronic devices and their manufacturing processes and, more particularly, to devices comprising a display screen and / or an image sensor.

Presentation of 1 ¹ prior art

Many computers, touch tablets, cell phones, connected watches, are equipped with an image sensor.

FIG. 1 partially and schematically represents an image sensor 10. The image sensor 10 comprises a matrix 11 of detection elements 12, called optical matrix thereafter. The detection elements 12 can be arranged in rows and columns. Each detection element 12 comprises a photodetector 14, for example a photodiode, and a selection element 16, for example a transistor whose source or drain is connected to a first electrode of the photodiode 14, for example the cathode. The image sensor 10 comprises a selection circuit 18 comprising, for each row, a conductive track 20 connected to the gates of the transistors 16 of selection. The image sensor 10 further comprises a read circuit 22 comprising, for each column, a conductive track 24 connected to the source or the drain of the column selection transistors 16. In addition, the second electrodes of the photodiodes 14, for example the anodes, can be connected by conductive tracks 26 to a source 28 of a reference potential.

It is known to produce the detection elements 12 at least partly in organic materials. The optical matrix 11 can then be made separately on a substrate and the selection circuit 18, the read circuit 22 and the potential source 28 can correspond to external circuits which are connected to the optical matrix 11. The optical matrix 11 comprises generally a stack of layers covered by a coating including protecting the organic photodiodes 14 against water and oxygen in the air. The coating may be a film which is attached to the optical matrix via an adhesive layer. A step of cutting the film is then provided after the fixing of the film on the optical matrix, in particular for exposing contact pads of the optical matrix 11 intended to be connected to the selection circuit 18, to the reading circuit 22 and to the source potential 28. The cutting step can be performed by means of a laser.

A disadvantage of such a manufacturing method is that the adjustment of the laser is difficult so that the laser cutting step can result in undesirable deterioration of the conductive tracks 22, 24, 26 located at the passage of the laser beam. In addition, when the substrate is plastic, it may be absorbent at the wavelengths of the laser so that the laser cutting step may result in undesirable damage to the substrate at the passage of the laser beam.

summary

An object of an embodiment is to overcome all or part of the disadvantages of the optoelectronic devices described above and their manufacturing processes. Another object of an embodiment is that the method of manufacturing the optoelectronic device comprises a cutting step, in particular a laser cutting step.

Another object of an embodiment is that the optoelectronic device comprises conductive tracks that are not deteriorated.

Another object of an embodiment is that the optoelectronic device comprises a substrate that is not deteriorated.

Another object of an embodiment is to provide an optoelectronic device comprising a display screen and / or an image sensor.

Another object of an embodiment is that the image sensor is, at least in part, made of organic semiconductor materials.

Another object of an embodiment is that all or part of the optoelectronic device can be produced by successive layers of layers by printing techniques, for example by inkjet, by heliography, by screen printing, by flexography or by by coating.

Thus, an embodiment provides an optoelectronic device comprising a substrate, a matrix of optoelectronic components covering the substrate, first conductive tracks connected to the optoelectronic components, an adhesive layer covering a part of the matrix and a coating in contact with the adhesive layer. the coating comprising a periphery, the device further comprising a second reflective and / or radiation absorbing track at a wavelength of between 335 nm and 10.6 μm and extending in line with the periphery in accordance with a given direction, between the first conductive tracks and the coating.

According to one embodiment, the second track is chosen from the group comprising:

a metal or a metal alloy, for example silver (Ag), gold (Au), lead (Pb), palladium (Pd), copper (Cu), nickel (Ni), tungsten (W), molybdenum (Mo), aluminum (Al), or chromium (Cr) or an alloy of magnesium and silver (MgAg);

carbon, silver and copper nanowires;

graphene;

a colored or black resin, for example a colored or black SU-8 resin; and

a mixture of at least two of these materials.

According to one embodiment, the device comprises a first electrically insulating layer and, for each optoelectronic component, an electrode in contact with the optoelectronic component, resting on the first insulating layer and in contact with the first insulating layer, the second track resting on the first insulating layer and in contact with the first insulating layer.

According to one embodiment, the second track is of the same material as the electrodes.

According to one embodiment, the device comprises a second electrically insulating layer, and for each optoelectronic component, a field effect transistor and third conductive tracks connecting the transistor to the optoelectronic component, resting on the second insulating layer and in contact with the second insulating layer, the second track being of the same material as the third tracks, resting on the second insulating layer and in contact with the second insulating layer.

According to one embodiment, the second track is interposed between the adhesive layer and the coating.

According to one embodiment, the optoelectronic components comprise organic photodetectors.

According to one embodiment, the optoelectronic components comprise organic electroluminescent components.

One embodiment provides a method of manufacturing the optoelectronic device as defined above. According to one embodiment, the method comprises the following steps:

forming the matrix of optoelectronic components covering the substrate and the first conductive tracks connected to the optoelectronic components;

covering the portion of the matrix of the adhesive layer;

applying a film in contact with the adhesive layer; and cutting the film using a laser beam extending in a given direction to obtain the coating, the method further comprising forming the second reflective and / or absorbing the laser beam and extending in line with the periphery coating in said direction given between the first conductive tracks and the coating.

Brief description of the drawings

These and other features and advantages will be set forth in detail in the following description of particular embodiments in a non-limiting manner with reference to the accompanying drawings in which:

FIG. 1, previously described, represents an electrical diagram of an exemplary image sensor;

Figures 2 and 3 are respectively a sectional view and a top view, partial and schematic, of an exemplary optical matrix of an image sensor;

FIGS. 4A to 4C are sectional, partial and schematic views of the structures obtained at successive stages of an embodiment of a method of manufacturing the optical matrix shown in FIGS. 2 and 3;

Figures 5 and 6 are respectively a sectional view and a top view, partial and schematic, of an embodiment of an optical matrix; and

Figures 7 to 9 are partial sectional and schematic views of embodiments of an optical matrix. detailed description

The same elements have been designated with the same references in the various figures. For the sake of clarity, only the steps and elements useful for understanding the embodiments that will be described have been shown and will be detailed. In particular, the operation of a display screen and an image sensor has not been detailed, the described embodiments being compatible with the display screens and the usual image sensors. In addition, the other components of the optoelectronic device incorporating a display screen and / or an image sensor have also not been detailed, the described embodiments being compatible with the other usual constituents of the optoelectronic devices with a screen. display and / or image sensor.

Unless otherwise specified, when reference is made to two elements connected together, it means directly connected without intermediate element other than conductors, and when reference is made to two elements connected or coupled together, it means that these two elements elements can be directly connected (connected) or connected via one or more other elements.

In the description which follows, when reference is made to the terms "" of the order of "and" substantially ", this means within 10%, preferably within 5%. absolute position qualifiers, such as "high", "low", etc., or relative, such as "above", "below", "above", "below", etc., are made reference, unless otherwise specified, to the orientation of the figures.

An active region of an optoelectronic component, in particular an electroluminescent component or a photodetector, is the region from which the majority of the electromagnetic radiation supplied by the optoelectronic component is emitted or the majority of the electromagnetic radiation received by the optoelectronic component is captured. In the rest of the description, an optoelectronic component is said organic when the active region of the optoelectronic component is predominantly, preferably completely, at least one organic material or a mixture of organic materials. In addition, a reflective element for radiation is called an element whose reflection factor for the radiation is greater than 80%, preferably greater than 90%, more preferably greater than 95%, the reflection factor being defined as the ratio between the flux of the reflected radiation and the flux of the incident radiation.

An embodiment will now be described for an optical matrix in the case where the optoelectronic components of the optical matrix are organic photodiodes. However, it is clear the optoelectronic components can correspond to electroluminescent components.

FIG. 2 is a partial sectional schematic side view of an example of an optical matrix 30 whose equivalent electrical diagram can correspond to the optical matrix 11 represented in FIG.

The optical matrix 30 comprises from bottom to top in FIG.

a substrate 32;

a stack 34 in which thin-film transistors are formed, a single transistor T being shown in FIG.

2;

electrodes 36, each electrode 36 being connected to one of the transistors T, a single electrode 36 being shown in FIG. 2;

photodetectors 38, for example organic photodiodes, also called OPD (English acronym for Organic Photodiode), a single photodiode 38 being shown in FIG. 2, each photodiode 38 being in contact with one of the electrodes 36;

an electrode 40 in contact with all organic photodiodes 38; a layer of an adhesive material 42; and a coating 44.

According to one embodiment, each photodiode 38 comprises an active region 46, the electrodes 36 and 40 being in contact with the active region 46. As a variant, each organic photodiode 38 may comprise a first interface layer in contact with the one of the electrodes 36, the active region 46 in contact with the first interface layer, and a second interface layer in contact with the active region 46, the electrode 40 being in contact with the second interface layer.

According to the present embodiment, the stack 34 comprises:

electrically conductive tracks 50, 51 resting on the substrate 32, the tracks 50 forming the gate conductors of the transistors T and the tracks 51 being connected to the drains or sources of the transistors T;

a layer 52 of a dielectric material covering the tracks 50, 51 and the substrate 32 between the tracks 50, 51 and forming the gate insulators of the transistors T;

active regions 54 resting on the dielectric layer 52 vis-à-vis the grid conductors 50;

electrically conductive tracks 56 extending over the dielectric layer 52, some of these tracks being in contact with the active regions 54 and forming the drain and source contacts of the transistors T, some of the tracks 56 being electrically connected to the tracks 51 by an electrically conductive vias intermediate 57 extending through the layer 52; and

a layer 58 of a dielectric material covering the active regions 54 and the electrically conductive tracks 56, the electrodes 36 resting on the layer 58 and being connected to some of the conductive tracks 56 by conductive vias 60 passing through the insulating layer 58 and electrode 40 being connected to some of the conductive tracks 51 by conductive vias, not shown in Figure 2, passing through the insulating layers 58 and 52.

Alternatively, the transistors T may be of the high gate type.

When at least one interface layer is present in contact with the active region 46, this interface layer may correspond to an electron-injecting layer or to a hole-injecting layer. The output work of each interface layer is adapted to block, collect or inject holes and / or electrons depending on whether this interface layer plays the role of a cathode or anode. More precisely, when the interface layer plays the role of anode, it corresponds to an injector layer of holes and electron blocker. The output work of the interface layer is then greater than or equal to 4.5 eV, preferably greater than or equal to 5 eV. When the interface layer acts as a cathode, it corresponds to an electron-injecting and hole-blocking layer. The output work of the interface layer is then less than or equal to 4.5 eV, preferably less than or equal to 4.2 eV.

In the present embodiment, the electrode 36 or 40 advantageously directly acts as an electron-injecting layer or a hole-injecting layer for the photodiode 38 and it is not necessary to provide for the photodiode 38 , an interface layer in contact with the active region 46 and acting as an electron-injecting layer or a hole-injecting layer.

The substrate 32 may be a rigid substrate or a flexible substrate. The substrate 32 may have a monolayer structure or correspond to a stack of at least two layers. An example of a rigid substrate comprises a substrate made of silicon, germanium or glass. Preferably, the substrate 32 is a flexible film. An example of a flexible substrate comprises a film made of PEN (polyethylene naphthalate), PET (polyethylene terephthalate), PI (polyimide), TAC (cellulose triacetate), COP (cycloolefin copolymer) or PEEK (polyetheretherketone). The thickness of the substrate 32 may be between 5 μm and 1000 μm. According to one embodiment, the substrate 32 may have a thickness of 10 μm to 300 μm, preferably between 75 μm and 250 μm, in particular of the order of 125 μm, and have a flexible behavior, that is to say say that the substrate 32 may, under the action of an external force, deform, including bending, without breaking or tearing. The substrate 32 may comprise at least one substantially oxygen-tight and moisture-tight layer in order to protect the organic layers of the optical matrix 30. It may be a layer or layers deposited by a deposition process of thin layers (ALD, Atomic Layer Deposition), for example a layer of Al2O3.

According to one embodiment, the material composing the electrodes 36, 40 is chosen from the group comprising:

a transparent conductive oxide (TCO), in particular indium tin-doped indium oxide (ITO), a zinc oxide and aluminum oxide (AZO, acronym for Aluminum Zinc Oxide), a gallium zinc oxide (GZO), an ITO / Ag / ITO alloy, an ITO / Mo / ITO alloy, an AZO / Ag / AZO alloy or a ZnO / Ag / ZnO alloy;

a metal or a metal alloy, for example silver (Ag), gold (Au), lead (Pb), palladium (Pd), copper (Or), nickel (Ni), tungsten (W), molybdenum (Mo), aluminum (Al), or chromium (Cr) or an alloy of magnesium and silver (MgAg);

carbon, silver and / or copper nanowires; graphene; and

a mixture of at least two of these materials.

The material composing the electrode 40 may also be chosen from the group comprising the PEDOT: PSS polymer, which is a mixture of poly (3,4) -ethylenedioxythiophene and sodium polystyrene sulphonate, or a polyaniline, the tungsten (WO3), nickel oxide (NiO), vanadium oxide (V2O5), or molybdenum oxide (M0O3). When the optical matrix 30 is exposed to light radiation, the latter reaches the photodiodes 38 through the coating 44, the electrode 40 and the coating 44 are at least partly transparent to the electromagnetic radiation captured by the photodiodes 38. electrode 40 is for example TCO. The electrodes 36 and the substrate 32 can then be opaque to the electromagnetic radiation captured by the photodiodes 38. When the radiation reaches the photodiodes 38 through the substrate 32, the electrodes 36 and the substrate 32 are a material at least partly transparent to the radiation. electromagnetic captured by the photodiodes 38. The electrodes 36 are for example TCO. The electrode 40 can then be opaque to the electromagnetic radiation captured by the photodiodes 38.

Each insulating layer 52, 58 may have a monolayer or multilayer structure and comprise at least one layer made of silicon nitride (SiN), silicon oxide (SiO 2) or a polymer, in particular a resin.

The layer of adhesive material 42 is transparent or partially transparent to visible light. The layer of adhesive material 42 is preferably substantially airtight and watertight. The material composing the layer of adhesive material 42 is selected from the group consisting of a polyepoxide or a polyacrylate. Among the polyepoxides, the material constituting the adhesive material layer 42 may be chosen from the group comprising bisphenol A epoxy resins, in particular the diglycidyl ether of bisphenol A (DGEBA) and the diglycidyl ether of bisphenol A and tetrabromobisphenol A, the epoxy resins bisphenol F, epoxy novolac resins, especially epoxy-phenol-novolac resins (EPN) and epoxy-cresol novolac resins (ECN), aliphatic epoxy resins, in particular epoxy resins with glycidyl groups and cycloaliphatic epoxides, epoxy glycidylamine resins, including glycidyl ethers of methylene dianiline (TGMDA), and a mixture of at least two of these compounds. Among the polyacrylates, the material constituting the layer of adhesive material 42 may be made from monomers including acrylic acid, methyl methacrylate, acrylonitrile, methacrylates, methyl acrylate, ethyl acrylate, 2-chloroethyl vinyl ether, 2-ethylhexyl acrylate, hydroxyethyl methacrylate, butyl acrylate, butyl methacrylate, trimethylolpropane triacrylate (TMPTA) and derivatives thereof.

When the layer of adhesive material 42 comprises at least one polyepoxide or a polyacrylate, the thickness of the layer of adhesive material 42 is between 1 μm and 50 μm, preferably between 5 μm and 40 μm, in particular of the order of 15 ym.

The coating 44 is a flexible film. An example of a flexible film comprises a film made of PEN (polyethylene naphthalate), PET (polyethylene terephthalate), PI (polyimide), TAC (cellulose triacetate), COP (cycloolefin copolymer) or PEEK (polyetheretherketone). The thickness of the coating 44 may be between 5 μm and 1000 μm.

According to one embodiment, the substrate 32 may have a thickness of 10 μm to 300 μm, preferably between 25 μm and 100 μm, in particular of the order of 50 μm, and have a flexible behavior, that is to say to say that the coating may, under the action of an external force, deform, in particular to bend, without breaking or tearing. The coating 44 may comprise at least one substantially oxygen-tight layer and moisture to protect the organic layers of the optical matrix 30. The coating 44 may comprise at least one layer of SiN, for example deposited by chemical deposition plasma-assisted vapor phase (PECVD) and / or a layer of aluminum oxide (Al 2 O 3), for example deposited by ALD.

The active region 46 comprises at least one organic material and may comprise a stack or a mixture of several organic materials. Active region 46 may comprise a mixture of an electron donor polymer and an electron acceptor molecule. The functional area of the active region 46 is delimited by the overlap between the lower electrode 36 and the upper electrode 40. The currents flowing through the functional zone of the active region 46 can vary from a few femtoamperes to a few microamperes. The thickness of the active region 46 covering the lower electrode 36 may be between 50 nm and 5 μm, preferably between 300 nm and 2 μm, for example of the order of 500 nm.

Active region 46 may include small molecules, oligomers or polymers. It can be organic or inorganic materials. The active region 46 may comprise an ambipolar semiconductor material, or a mixture of an N-type semiconductor material and a P-type semiconductor material, for example in the form of superposed layers or of an intimate mixture at the nanoscale so to form a heterojunction by volume.

Examples of P-type semiconductor polymers suitable for producing active region 42 are poly (3-hexylthiophene) (P3HT), poly [N-9'-heptadecanyl-2,7-carbazole-alt-5,5 (4, 7-di-2-thienyl-2 ', 1', 3'-benzothiadiazole)] (PCDTBT), Poly [(4,8-bis (2-ethylhexyloxy) -benzo [1,2- b, 4,5-b'-dithiophene) -2,6-diyl-alt- (4- (2-ethylhexanoyl) thi no [3,4-b] thiophene) -2,6-diyl]; 4, 5-b '] dithi-ophene) -2,6-diyl-alt- (5,5'-bis (2-thienyl) -4,4-dininyl-2,2'-bithiazole) -5' , 5 '' -diyl]

(PBDTTT-C), poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylenevinylene] (MEH-PPV) or Poly [2,6- (4,4) bis (2-ethylhexyl) -4H-cyclopenta [2,1-b; 3,4-b '] dithiophene) -ait-4,7 (2,1,3-benzothiadiazole)] (PCPDTBT).

Examples of N-type semiconductor materials suitable for producing the active region 42 are fullerenes, especially C60, methyl [6, 6] -phenyl-C8 _] -butanoate ([60JPCBM), [6, 6], 6] -phenyl-α-butanoate methyl ([70JPCBM), perylene diimide, zinc oxide (ZnO) or nanocrystals allowing the formation of quantum dots, in English quantum dots. In the case where an interface layer is present and the interface layer acts as an electron-injecting layer, the material composing the interface layer is selected from the group consisting of:

a metal oxide, especially a titanium oxide or a zinc oxide;

a molecular host / dopant system, especially the products marketed by Novaled under the names NET-5 / NDN-1 or NET-8 / MDN-26;

a doped conductive or semiconductive polymer, for example the PEDOT: Tosylate polymer which is a mixture of poly (3,4) -ethylenedioxythiophene and tosylate;

carbonate, for example CsCO3;

a polyelectrolyte, for example poly [9,9-bis (3 '- (N, N-dimethylamino) propyl) -2,7-fluorene-alt-2,7- (9,9-dioctylfluorene)] (PFN) poly [3- (6-trimethylammoniumhexyl) thiophene] (P3TMAHT) or poly [9,9-bis (2-ethylhexyl) fluorene] - b-poly [3- (6-trimethylammoniumhexyl) thiophene (PF2 / 6- b- R3TMDHT);

a polyethyleneimine polymer (PEI) or an ethoxylated polyethyleneimine polymer (PEIE) polymer, propoxylated and / or butoxylated;

MgAg;

tris (8-hydroxyquinoline) aluminum (III) (Alq3); 2- (4-Biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (Bu-PBD); and

a mixture of two or more of these materials. In the case where an interface layer is present and the interface layer acts as a hole-injecting layer, the material constituting the interface layer may be selected from the group consisting of:

a doped conductive or semiconductor polymer, in particular the materials marketed under the names Plexcore OC RG-1100, Plexcore OC RG-1200 by Sigma-Aldrich, PEDOT: PSS; a molecular host / dopant system, especially the products marketed by Novaled under the names NHT-5 / NDP-2 or NHT-18 / NDP-9;

a polyelectrolyte, for example the Nation;

a metal oxide, for example a molybdenum oxide, a vanadium oxide, ITO, or a nickel oxide;

Bis [(1-naphthyl) -N-phenyl] benzidine (NPB); triarylamines (TPD); and

a mixture of two or more of these materials. Preferably, in the case where the interface layer plays the role of a hole-injecting layer, the material constituting the interface layer is a doped conductive or semiconductor polymer.

In the case where the optical matrix comprises electroluminescent components, in particular organic light-emitting diodes, the active region of the light-emitting diode is for example a light-emitting material. The electroluminescent material may be a polymeric electroluminescent material, as described in the publication entitled "Progress with Light-Emitting Polymers" by MT Bernius, M. Inbasekaran, J. O. Brien and W. Wu (Advanced Materials, 2000, Volume 12 , Issue 23, pages 1737-1750) or a low molecular weight electroluminescent material such as trisquinoline aluminum, as described in US Pat. No. 5,294,869. The electroluminescent material may comprise a mixture of electroluminescent material and a fluorescent dye or may comprise a layered structure of electroluminescent material and a fluorescent dye. Light-emitting polymers include polyfluorene, polybenzothlazole, polytriarylamine, poly

(phenylenevinylene) and polythophene. Preferred light emitting polymers include homopolymers and copolymers of 9, 9-di-n-octylfluorene (F8), N, N-bis (phenyl) -4-sec-butylphenylamine (TFB), benzothiadiazole (BT) and 4,4'-N, N '-dicarbazole-biphenyl (CBP) doped with tris (2- phenylpyridine) of iridium (Ir (ppy) 3). The thickness of the active region 46 is between 1 nm and 100 nm.

The conductive tracks 50, 51, 56 may be of the same material as the electrodes 36 or 40. The thickness of the conductive tracks 50, 51 may be less than 50 μm.

The active regions 54 may be of polycrystalline silicon, in particular polycrystalline silicon deposited at low temperature (LTPS), amorphous silicon (aSi), zinc oxide-gallium-indium (IGZO), polymer or comprise small molecules used in a known manner for the production of thin-film organic transistors (OTFT, acronym for Organic Thin Film Transistor).

Each insulating layer 52, 58 may be SiN, SiO2 or an organic polymer. The insulating layer 52 may have a thickness of between 10 nm and 4 μm and the insulating layer 58 may have a thickness of between 10 nm and 4 μm.

The optical matrix 30 may further comprise a polarizing filter, arranged for example on the coating 44. The optical matrix 30 may further comprise color filters vis-à-vis the photodetectors 38 to obtain a wavelength selection radiation reaching the photodetectors 38.

FIG. 3 is a top view, partial and schematic, of the optical matrix 30 shown in FIG. 2. FIG. 3 shows by dashed lines 60 the outline of the zone in which the photodiodes 38 are formed, and by solid lines and dashed lines 62 the contours of the zones in which are formed the conductive tracks 50 and 51. We also represented by a solid line the periphery 64 of the coating 44. As appears in Figure 3, a portion of zones 62, shown in solid lines, is not covered by the coating 44 so as to allow connection to the conductive tracks 50, 51 of the selection circuit 18, the read circuit 22 and the potential source 28, not shown in figure 3. FIGS. 4A to 4C are sectional, partial and schematic views of structures obtained at successive stages of an embodiment of a method for manufacturing the optical matrix 30.

FIG. 4A shows the structure obtained after the formation of the stack of layers comprising the transistors T, the electrodes 36, the photodetectors 38, the electrode 40 and the layer of the adhesive material 42.

Depending on the materials considered, the process for forming the layers of the optical matrix may correspond to a so-called additive process, for example by direct printing of the material making up the organic layers at the desired locations, in particular in the form of sol-gel, for example by printing with inkjet, heliography, screen printing, flexography, spray coating (English spray coating) or drop-casting. According to the materials considered, the process for forming the layers of the optical matrix may correspond to a so-called subtractive process, in which the material making up the organic layers is deposited on the entire structure and in which the unused portions are then removed, for example by photolithography or laser ablation. Depending on the material considered, the deposition on the entire structure may be carried out for example by liquid, sputtering or evaporation. This may include processes such as spin coating, spray coating, heliography, slot-die coating, blade-coating, flexography or screen printing. When the layers are metallic, the metal is, for example, deposited by evaporation or cathodic sputtering on the entire support and the metal layers are defined by etching.

Advantageously, at least some of the layers of the optical matrix can be made by printing techniques. The materials of these layers described above can be deposited in liquid form, for example in the form of conductive, semiconducting or insulating inks using inkjet printers. By materials in liquid form, here also means gel materials deposited by printing techniques. Annealing steps are optionally provided between the deposits of the different layers, but the annealing temperatures may not exceed 150 ° C, and the deposition and any annealing may be carried out at atmospheric pressure.

Figure 4B shows the structure obtained after the deposition of a film 68 of the same material as the desired coating 44. This can be achieved by a lamination step in which the film 68 is applied against the adhesive layer 42, possibly under pressure and with heating.

Figure 4C shows the structure obtained after a film cutting step 68 to form the coating 44. The cutting step may be a laser cutting step. By way of example, the laser is a continuous CO2 type laser with a wavelength of between 9.4 μm and 10.6 μm. For example, the power of the laser is between 1 W and 100 W, the speed of movement between 1 cm / s and 10 m / s. An alternative is to use a continuous nitrogen laser with a wavelength of 337.1 nm or a pulsed laser Yag with wavelengths 1050 nm to 1070 nm, 1550 nm or 2100 nm. The cutting is preferably done with a CO2 laser. The path followed by the laser beam is indicated schematically in FIG. 4C by arrows 64.

The inventors have demonstrated that the laser cutting step can lead to a deterioration of the conductive tracks 50, 51 by the laser beam, and in particular a localized interruption of the conductive tracks 50, 51 on the laser path. In addition, in the case where the substrate 32 is of a plastic material, the substrate 32 can absorb the laser beam, which can cause localized deterioration of the substrate 32 on the laser path. The inventors have demonstrated that the deteriorations due to the laser cutting step can be avoided by providing a track of a material reflecting the laser radiation and / or a material absorbing the laser radiation on the path of the laser when of the cutting step, this track being interposed between the laser beam on the one hand and the conductive tracks 50, 51 and the substrate 32 on the other hand. Preferably, the width of this track is greater than 500 μm, preferably greater than 1 mm.

Figures 5 and 6 are respectively a sectional view and a top view, partial and schematic, of an embodiment of an optical matrix 70 comprising a protection for the cutting step. The optical matrix 70 comprises all the elements of the optical matrix 30 shown in FIG. 2 and furthermore comprises at least one reflecting track 72 resting on the insulating layer 58 on the film cutting path 68. According to a method of FIG. realization, the reflective track 72 is an electrically conductive track made simultaneously with the electrodes 36 and the same material as the electrodes 36 when the electrodes 36 are reflective material.

FIG. 7 is a partial, schematic sectional view of an embodiment of an optical matrix 75 comprising a protection for the cutting step. The optical matrix 75 comprises all the elements of the optical matrix 30 shown in FIG. 2 and further comprises a reflective track 76 resting on the insulating layer 52 on the cutting path of the film 68. According to one embodiment, the reflective track 76 is an electrically conducting track made simultaneously with the tracks 56 and of the same material as the tracks 56.

According to one embodiment, the material composing the track 72 or 76 is chosen from the group comprising:

an ITO / MB / ITO stack;

carbon, silver and / or copper nanowires; graphene; and

a mixture of at least two of these materials.

The thickness of the track 72 or 76 may be between 10 nm and 10 μm.

When the track 72, 76 is electrically conductive, it can be connected, during the operation of the optical matrix, to a source of a low reference potential, for example ground, at the potential source 28 or at a source of the potential controlling the closing of transistors T.

FIG. 8 is a partial, schematic sectional view of an embodiment of an optical matrix 80 comprising a protection for the cutting step. The optical matrix 80 comprises all the elements of the optical matrix 30 shown in FIG. 2 and further comprises a track 82 of a material absorbing laser radiation and resting on the insulating layer 58 on the cutting path of the laser. The track 82 may be of colored resin, for example a colored or black SU-8 resin. In the present embodiment, the track 82 is formed on the insulating layer 58 before the deposition of the adhesive layer 42, for example according to one of the additive or subtractive process techniques described above. The thickness of the track 82 may be between 100 nm and 50 μm.

FIG. 9 is a partial, schematic sectional view of an embodiment of an optical matrix 85 comprising a protection for the cutting step. Optical matrix 85 comprises all the elements of the optical matrix 30 shown in FIG. 2 and further comprises a track 86 of a laser radiation absorbing material resting on the adhesive layer 42 on the coating cutting path. 44. Runway 86 may be of the same material as runway 82. In the In this embodiment, the track 86 is formed on the adhesive layer 42 before applying the film forming the coating 44 for example according to one of the additive or subtractive process techniques described above.

Various embodiments with various variations have been described above and various variations and modifications occur to those skilled in the art. It is noted that one skilled in the art can combine various elements of these various embodiments and variants without being creative. In particular, the optical matrix may comprise both photodetectors and electroluminescent components.

Claims

1. Optoelectronic device comprising a substrate

(32), a matrix (70; 75; 80; 85) of optoelectronic components (38) covering the substrate, first conductive tracks (50,51) connected to the optoelectronic components, an adhesive layer (42) covering a portion of the a matrix and a coating (44) in contact with the adhesive layer (42), the coating including a periphery (64), the device further comprising a second track (72; 76; 82; 86) reflecting radiation at a length of Wavelength between 335 nm and 10.6 μm and extending aligned with the periphery in a given direction between the first conductive tracks and the coating.

Optoelectronic device according to claim 1, wherein the second track (72; 76; 82; 86) is selected from the group consisting of:

carbon, silver and / or copper nanowires; graphene;

a colored or black resin, for example a colored or black SU-8 resin; and

a mixture of at least two of these materials.

Optoelectronic device according to claim 1 or 2, comprising a first electrically insulating layer (58) and, for each optoelectronic component, an electrode (36) in contact with the optoelectronic component (38), resting on the first insulating layer and in contact the first insulating layer, the second track (72; 82) resting on the first insulating layer and in contact with the first insulating layer.

Optoelectronic device according to claim 3, wherein the second track (72) is of the same material as the electrodes (36).

Optoelectronic device according to claim 1 or 2, comprising a second electrically insulating layer (52), and for each optoelectronic component (38), a field effect transistor (T) and third conductive tracks (56) connecting the transistor the optoelectronic component, resting on the second insulating layer and in contact with the second insulating layer, the second track (76) being of the same material as the third tracks, resting on the second insulating layer and in contact with the second insulating layer.

Optoelectronic device according to claim 1 or 2, wherein the second track (86) is interposed between the adhesive layer (42) and the coating (44).

An optoelectronic device according to any one of claims 1 to 6, wherein the optoelectronic components (38) comprise organic photodetectors.

Optoelectronic device according to any one of claims 1 to 7, wherein the optoelectronic components (38) comprise organic electroluminescent components.

9. A method of manufacturing the optoelectronic device according to any one of claims 1 to 8.

The method of claim 9, comprising the steps of:

forming the matrix (70; 75; 80; 85) of optoelectronic components (38) covering the substrate (32) and the first conductive tracks (50,51) connected to the optoelectronic components;

cover the part of the matrix of the adhesive layer

(42); applying a film (68) in contact with the adhesive layer

(42); and

cutting the film using a laser beam extending in the given direction to obtain the coating (44),

the method further comprising forming the second track (72; 76; 82; 86) reflecting the laser beam and extending in alignment with the perimeter of the coating (44) in said given direction between the first conductive tracks and the coating.