Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K50/00—Organic light-emitting devices
  • H10K50/80—Constructional details
  • H10K50/805—Electrodes
  • H10K50/81—Anodes
  • H10K50/814—Anodes combined with auxiliary electrodes, e.g. ITO layer combined with metal lines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y40/00—Manufacture or treatment of nanostructures
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K2102/00—Constructional details relating to the organic devices covered by this subclass
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K50/00—Organic light-emitting devices
  • H10K50/80—Constructional details
  • H10K50/85—Arrangements for extracting light from the devices

Definitions

• the present invention relates to a carrier substrate of an electrode, the organic electroluminescent device incorporating it and its manufacture.
• the known organic electroluminescent systems or OLED comprise a material or a stack of organic electroluminescent materials supplied with electricity by electrodes generally framing in the form of electroconductive layers.
• the upper electrode is a reflective metal layer, for example aluminum
• the lower electrode is a transparent layer based on indium oxide, generally the indium oxide doped with tin better known under the abbreviation ITO of thickness of the order of 100 to 150 nm.
• ITO abbreviation
• US7172822 also proposes an OLED device whose electrode closest to the substrate comprises an irregular network conductor obtained by filling a cracked mask. More specifically, between the glass substrate and the OLED active layer, the OLED device successively comprises:
• a gel-sol layer forming the microfissured mask after annealing, of thickness equal to 0.4 ⁇ m; the grating conductor, based on gold, obtained by catalytic deposition, this network conductor having an equal square resistance of 3 Ohm / square and a light transmission of 83%,
• the domains between the fracture lines are asymmetrical with two characteristic dimensions: one parallel to the crack propagation direction between 0.8 and 1 mm, the other perpendicular between 100 and 200 ⁇ m.
• This electrode has electroconductive properties and acceptable transparency, the square resistance being equal to 3 Ohm / square and the light transmission of 82%.
• the reliability of the OLED device with such an electrode is not assured.
• the manufacture of the electrode can be further improved.
• a soil based on water, alcohol and a silica precursor (TEOS) is deposited, the solvent is evaporated and annealed at 120 ° C. for 30 minutes.
• This method of manufacturing an electrode by cracking of the sol gel mask constitutes an advance for the manufacture of a network conductor by eliminating for example the use of photolithography (exposure of a resin to a radiation / beam and development), but can still be improved, especially to be compatible with industrial requirements (reliability, simplification and / or reduction of manufacturing steps, at a lower cost, etc.). It may also be noted that the manufacturing process of the network necessarily requires the deposition of an modifiable sub-layer (chemically or physically) at the openings to either allow a preferred adhesion (of metal colloids for example) or allow the grafting of catalyst for post-growth of metal, this sub-layer therefore having a functional role in the growth process of the network.
• the crack profile is in fact the fracture mechanics of the elastic material, which involves using a post-mask process to grow the metal network from the colloidal particles. located at the base of V.
• the aim of the invention is to obtain a high performance OLED electrode (high conductivity, adapted transparency) which is reliable, robust, reproducible, and can be produced over large areas, all on an industrial scale and preferably at a lower cost and as easily as possible.
• this electrode also contributes to increasing the overall performance of the OLED device (light output, uniformity of illumination, etc.).
• the present invention firstly relates to a carrier substrate on a main face of a composite electrode, which comprises:
• an electroconductive network formed by the strands which is a layer (monolayer or multilayer) of electroconductive material (s) based on metal and / or metal oxide, the grating having a light transmission of at least 60% at 550 nm, or even an integrated light transmission T L of at least 60%, the space between the strands being filled with a so-called electrically insulating filling material,
• an electroconductive coating covering (entirely) the electroconductive network, with a thickness greater than or equal to 40 nm, in electrical connection with the strands and in contact with the strands, with a pI resistivity of less than 10 5 ohm. cm and greater than the resistivity of the material forming the strands of the network, the coating forming a smoothed electrode outer surface,
• the composite electrode further having a square resistance less than or equal to 10 Ohm / square.
• the composite electrode according to the invention thus comprises a buried electroconductive network whose surface is smoothed to avoid introducing electrical faults in the OLEDs.
• the filling material as a function of its thickness significantly reduces, or even eliminates, the difference between the high level and the low level of the electrode network.
• the electroconductive coating eliminates the risk of short circuits generated by spike effects ("spike effect"). resulting from uncontrolled surface microroughness of the strands and / or the surface of the filling material between the strands.
• the electroconductive coating according to the invention thus makes it possible either to smooth the network and the filling material or at least to maintain a previously obtained smoothing (for example by polishing).
• the network conductor described in US7172822 is covered with a thin polymeric layer that matches the difference in level between the network conductor and the cracked mask.
• the invention is thus based on an electrode network of strands that can be relatively thick and / or spaced, to control the roughness of the electrode on several scales (first by burying the network to remove the steps abrupt and then smoothing it sufficiently) and, to ensure adequate electrical and transparency properties of an electrode made of several materials (strand material (s), filler, electroconductive coating material) or even to improve OLED performance.
• the insulating filler may be mono or multicomponent, mono or multilayer. It may preferably be distinct from a simple passivation resin.
• the electroconductive coating according to the invention by virtue of its resistivity, its coverage of the network and its thickness, contributes to a better distribution of the current.
• the resistivity of the electroconductive coating pi may be less than or equal to 10 3 Ohm. cm, and even less than or equal to 10 2 Ohm. cm.
• the network may be in the form of lines for example parallel or in the form of closed patterns (strands interconnected between them, defining meshes), for example geometric (rectangle, square, polygon %) and possibly patterns, irregular shape and / or irregular size.
• B the average distance between the strands (especially corresponding to an average mesh size)
• A the average width of the strands
• B + A the average period of the possibly irregular network. The shorter the mean distance B between strands (dense network), the higher the resistivity of the electroconductive coating.
• the filling material is insulating.
• the resistivity pi may preferably be less than or equal to 10 -1 ohm.cm, in particular when the network is dense (typically less than or equal to 50 ⁇ m) When the network is sparse (typically greater than 50 ⁇ m), the resistivity pi may then even more preferably be less than or equal to 10 -2 ohm. cm or even less than or equal to 10 "4 Ohm cm.
• the resistivity pi may be at least ten times greater than p2 to decrease sensitivity to short circuits.
• the surface of the electroconductive coating is the outer electrode surface.
• the surface of the electroconductive coating may preferably be intended to be in contact with the organic layers of the OLED: in particular the hole injection layer ("HIL” in English) and / or the hole transport layer (“HTL”). " in English).
• the surface of the electrode according to the invention is not necessarily planarized by the coating. It can be wavy.
• the electroconductive coating can smooth the surface first by forming sufficiently spreading undulations. It is thus important to delete sharp angles, steep gaps.
• the external surface is such that starting from a real profile of the external surface over the average period of the B + A grating and forming a profile corrected by nanometric filtering to eliminate the local microroughness, one obtains, in any point of the corrected profile, an angle formed by the tangent corrected profile with the average plane of the corrected profile (or real) less than or equal to 45 °, even more preferably less than or equal to 30 °.
• an atomic force microscope can be used.
• An image of the real surface is formed over a square period (A + B) 2 of the network. This image or a section of this image is used, thus forming the real profile of the surface along a given axis.
• the analysis length A + B for the profile is useful because it reflects the roughness profile.
• the average period of the B + A network is typically submillimetric, preferably between 10 ⁇ m and
• the real profile is corrected by realizing (at any point) a moving average at the scale between 50 and 200 nm, for example 100 nm, and then, for each point, the angle between the mean plane and the tangent to the profile is determined. .
• This nanometric filtering serves firstly to rule out accidents on a short scale.
• the residual profile that is to say the actual profile minus the corrected profile.
• the residual profile can thus present a maximum altitude difference between the highest point and the lowest point ("peak to valley" parameter) less than 50 nm, even more preferably less than or equal to 20 nm, or even 10 nm, over the average period of the B + A network.
• the residual profile may also have a roughness parameter R.M.S of less than or equal to 50 nm, or even 20 nm (otherwise called Rq) or even 5 nm over the average period of the B + A network.
• RMS stands for "Root Mean Square” roughness. This is a measure of measuring the value of the mean square deviation of roughness.
• the RMS parameter therefore, quantifies on average the height of the peaks and troughs of residual roughness (local microroughness), compared to the average height (residual). So, a 10 nm RMS means an amplitude double peak.
• the boundary conditions on the angles and the residual micro-roughness can preferably be satisfied on the majority of the electrode surface. To verify this, measurements can be made on different areas distributed (evenly) over the entire surface.
• the electrode edges being able to be passive, for example for the connection or to form several light zones.
• the angle measurements can also be made in another way by a mechanical system tip (using for example the measuring instruments marketed by VEECO under the name DEKTAK).
• the outer surface of the electroconductive coating may further have very large scale corrugations, typically one or more millimeters.
• the substrate, and by the same the external surface, can be curved.
• the light transmission of the network depends on the ratio B / A between the average distance between the strands B on the average width of the strands A.
• the ratio B / A is between 5 and even more preferably of the order of 10 to easily retain transparency and facilitate manufacture.
• B and A are respectively approximately 300 .mu.m and 30 .mu.m, 100 .mu.m and 10 .mu.m, 50 .mu.m and 5 .mu.m, or 20 .mu.m and 2 .mu.m.
• microns typically between 100 nm and 30 microns, preferably less than or equal to 10 microns, or even 5 microns to limit their visibility and greater than or equal to 1 micron to facilitate manufacture and to easily maintain high conductivity and transparency.
• the preferred range is between 1 and 10 ⁇ m.
• an average distance between strands B greater than A between 5 ⁇ m and 300 ⁇ m, or even between 20 and 100 ⁇ m, to easily retain transparency.
• the dimensions A and B are therefore average dimensions.
• the average thickness of the strands can be between 100 nm and 5 ⁇ m, more preferably 0.5 to 3 ⁇ m, or even between 0.5 and 1.5 ⁇ m to easily maintain transparency and high conductivity.
• the composite electrode according to the invention can present:
• the composite electrode according to the invention can be used for a rear emission organic electroluminescent device ("bottom emission” in English) or for an organic emitting device emitting from the rear and the front.
• the light transmission T L may for example be measured on a T L substrate of the order of 90% or even more, for example a silicosocalocalic glass.
• the composite electrode according to the invention may be over a large surface, for example an area greater than or equal to 0.02 m 2 or even greater than or equal to 0.5 m 2 or 1 m 2 .
• an electroconductive material can cover the strands without smoothing the surface sufficiently.
• deposition techniques by gaseous, chemical (“CVD” in English) or physical (PVD in English), including vacuum deposition (evaporation, spraying) reproduce or even amplify the irregularities of the initial surface. Then, to obtain a smoothed external surface, it is then necessary to carry out a subsequent operation of surfacing an electroconductive material, for example by mechanical action (polishing type).
• a technique of liquid deposition including at least one the following techniques: by printing (plane, rotary ...), in particular by flexographic printing, by gravure printing or else by liquid spray ("spray coating” in English), dip coating ("dip coating” in English), curtain (“curtain” in English), by casting ("flow coating” in English), spin coating (“spin coating” in English), scraping ("blade coating” in English), by draw (“wire-bar”).
• the deposit may also be obtained by sol-gel route.
• the thickness of the electroconductive coating may be between 40 and 1000 nm and preferably between 50 and 500 nm.
• the electroconductive coating may for example comprise or consist of a layer of transparent oxide (s) conductor (s) (TCO).
• TCO transparent oxide conductor
• doped or alloyed zinc oxide with at least one of the following elements: aluminum, gallium, indium, boron, tin (for example ZnO: Al, ZnO: Ga, ZnO: In, ZnO: B, ZnSnO), indium oxide doped or alloyed in particular with zinc (IZO), gallium and zinc (IGZO), tin (ITO),
• the filling material it is possible to choose other oxides, especially high index ones, in particular:
• zirconium oxide ZrO 2
• titanium oxide TiO 2
• tantalum oxide (Ta 2 O 5 )
• nitrides such as Si 3 N 4 , AlN, GaN, optionally doped with Zr, or else stoichiometric silicon carbide SiC.
• the electroconductive coating may for example comprise a layer containing metal nanoparticles or transparent conductive oxides, as mentioned above, preferably between 10 and 50 nm to better limit and control the roughness of the deposit, nanoparticles optionally and preferably in a binder.
• the filling material may for example comprise or consist of a gel sol layer including metal oxides (non-conductive), single or mixed such as those mentioned above.
• the filler may for example comprise or consist of a layer containing (nano) particles or oxides (non-conductive) as mentioned above.
• the nanoparticles are preferably of size between 10 and 50 nm to better limit and control the roughness of the deposit and prepare the smoothing by an overlying electroconductive coating.
• the (nano) particles are (nano) particles optionally in a binder.
• the binder can be organic, for example acrylic resins, epoxy, polyurethane, or be developed by sol-gel (mineral, or inorganic organic hybrid ).
• the nanoparticles can be deposited from a dispersion in a solvent (alcohol, ketone, water, glycol, etc.).
• a solvent alcohol, ketone, water, glycol, etc.
• the dispersions alone are mechanically weak because of the absence of binder between the particles. Also in order to ensure the cohesion of the layer of the coating, it is preferred to mix them in a binder before they are deposited (binder distributed over the entire thickness of the filling layer).
• the binder may be electrically insulative or electroconductive.
• the binder can be organic, for example acrylic resins, epoxy, polyurethane.
• the binder can be prepared by sol-gel (mineral, or inorganic organic hybrid ).
• the binder can be based on organometallic precursors preferably of the same chemical nature as the nanoparticles of metal oxides.
• the desired resistivity for the coating is adjusted according to the formulation.
• the electroconductive coating (and / or the filler) may comprise an essentially inorganic or inorganic organic hybrid layer, for example a gel sol layer, in particular based on metal oxides and / or conductive, single or mixed such as those mentioned above.
• an essentially inorganic or inorganic organic hybrid layer for example a gel sol layer, in particular based on metal oxides and / or conductive, single or mixed such as those mentioned above.
• Soil-gels have the advantage of supporting even high heat treatments (eg quench type operation) and to resist UV exposures.
• a sol gel layer for the electroconductive coating In order to manufacture a sol gel layer for the electroconductive coating, commercially available transparent conductive oxide precursors are preferably chosen, in particular organometallic compounds or salts of these metals.
• precursors for tin oxide deposits SnCl 4 , sodium stannate, SnCl 2 (OAc) 2 , Sn (IV) alkoxide such as Sn (OtBu) can be chosen. 4 . It is also possible to choose any salt or organometallic compound known as a precursor of tin. For the antimony oxide deposits, it is possible to choose organometallic compounds and salts, in particular Sb (III) alkoxides and chlorides such as SbCl 3 or SbCl 5 .
• Mixed and / or doped oxide layers are obtained for example by mixing the precursors in the appropriate proportions and using the solvents compatible with said precursors.
• an antimony-doped tin oxide layer can be obtained from tin chloride and antimony chloride dissolved in water in the presence of urea and hydrochloric acid.
• Another example of elaboration consists in using tin tetraisopropoxide as a precursor in a water / alcohol / ethanolamine mixture and adding antimony chloride as a dopant.
• DX-400® sold by Sumitomo Metal Mining Co. Ltd. It is a paste based on tin and indium alkoxides, organic solvent and viscosity control agent.
• the composite electrode preferably has a limited ITO content for cost reasons.
• an ITO gel sol layer based on organometallic precursors has a maximum thickness of 150 nm, or even 50 nm.
• the precursors of the alkoxide metal oxides are used, for example, diluted in an organic solvent, for example a volatile alcohol.
• volatile alcohols linear or branched C1 to C10 alcohols, in particular methanol, ethanol, hexanol, isopropanol or glycols, in particular ethylene, may be selected.
• glycol or volatile esters such as ethyl acetate.
• composition used for the deposition of the sol gel layer may advantageously also comprise other constituents, in particular water as a hydrolysis agent, a stabilizing agent such as diacetone alcohol, acetylacetone, acetic acid, formamide.
• a stabilizing agent such as diacetone alcohol, acetylacetone, acetic acid, formamide.
• the precursors of the metal salt type are generally used in solution in water.
• the pH of the water can be adjusted by using acids or bases (for example hydrochloric acid, acetic acid, ammonia, sodium hydroxide) to control the condensation conditions of the precursors.
• Stabilizers such as diacetone alcohol, acetylacetone, acetic acid, formamide can also be used.
• drying is generally carried out between 20 and 150 ° C., advantageously at a temperature of the order of 100 ° C., followed by a heat treatment at a temperature of about 450 to 600 ° C. for a period of time. between a few minutes and a few hours, advantageously at a temperature of the order of 550 ° C. for a duration of the order of 30 minutes.
• the electroconductive coating may comprise or consist of a substantially polymer layer deposited by a liquid route optionally possibly capable of forming a binder for the (nano) oxide particles of a filler layer.
• polythiophenes such as PEDOT (3,4-polyethylenedioxythiopene), PEDOT / PSS c that is, (3,4-polyethylenedioxythiopene mixed with polystyrene sulfonate, and other derivatives described in US2004253439, or poly (acetylene) s, poly (pyrrole) s, poly (aniline) s, poly ( fluorene) s, poly (3-alkyl thiophene) s, polytetrathylyvalenes, polynaphthalenes, poly (p-phenylene sulfide), and poly (para-phenylene vinylene) s.
• polythiophenes such as PEDOT (3,4-polyethylenedioxythiopene), PEDOT / PSS c that is, (3,4-polyethylenedioxythiopene mixed with polystyrene sulfonate, and other derivatives described in US2004253439, or
• polythiophenes it is possible to choose, for example, the product marketed by HC Strack under the name BAYTRON® or by the company Agfa under the name Orgacon®, or Orgacon EL-P3040®.
• the conductive polymer is part of the electrode and may also serve as a hole injection layer.
• a "TCO" layer developed from precursors is smoother than a layer made from (nano) particles.
• the composite electrode, at least the filler and / or the electroconductive coating present in the CIELAB diagram colorimetric coordinates a * and b * less than 5 in absolute value.
• the network arrangement can be obtained directly by deposit (s) electroconductive material (s) to reduce manufacturing costs.
• This direct network arrangement can be obtained directly by one or more appropriate deposit methods, for example by using an ink pad, or by ink jet (with a suitable nozzle).
• the electroconductive network may also be obtained directly by electroconductive deposition (s) through an array of openings of a mask on the substrate (permanent mask or subsequently removed), or even by electroconductive deposition (s). in an etching network of the substrate formed for example by etching through said mask for example to a depth from 10 nm, preferably not beyond 100 nm, in particular of the order of 50 nm. This can promote the anchoring of the strands.
• a fluorinated plasma etching in particular under vacuum, for example by CF 4 , CHF 3 .
• CF 4 , CHF 3 under vacuum
• oxygen atmosphere it is possible to control the etching rate of the mask chosen in particular organic.
• the arrangement of the strands can be, then substantially the replica of that of the network of openings of the mask or the etching network.
• a stable mask is preferably chosen without resorting to a annealing.
• a non-selective deposition technique can be chosen, the deposit filling at the same time a fraction of the openings of the mask or the etching network and also covering the surface of the mask or the substrate. We can then remove the mask or polish the surface.
• a deposition by liquid route in particular by printing, by scraping an electroconductive ink and / or a vacuum deposition technique such as spraying, or even more preferably by evaporation.
• the deposit (s) may optionally be supplemented by an electrolytic refill using an Ag, Cu, Gold electrode or other high conductivity metal that can be used.
• the electroconductive network is deposited (entirely or in part) in a substrate etching network, in particular glass, for etching the substrate wet (for example with an HF solution for the glass), it is possible to choose a ground gel mask with an adequate network of openings.
• the electroconductive network can be obtained by deposition (s) electroconductive material (s) in a network of self-generated openings of a mask on the substrate.
• the network of self-generated openings can for example be obtained by baking a continuous deposit of a suitable material for this purpose. These may be interstices or cracks, especially those described in document US Pat. No. 7,172,222.
• the reduction in the number of technological steps necessary to produce such a self-blown mask has a favorable influence on the production yields and costs of the desired final product.
• the self-generating openings, and thus the strands, can be irregular, distributed aperiodically, (pseudo) random.
• the mask preferably with autogenerated openings, is removed before depositing the electroconductive smoothing coating.
• the electroconductive coating can at least partially fill the space between the strands, at least the upper part between the strands (furthest from the substrate).
• Its thickness can be in particular be at least one and a half times, or even twice the height of the strands.
• an electroconductive coating deposited for example by printing (flexography in particular), by liquid spraying, by dipping, coating deposited in one or more passes.
• the space between the strands is filled, preferably over its entire height, with a so-called high index filling material having a refractive index greater than or equal to 1.65 at least at 550 nm, preferably throughout visible, even more preferably a refractive index between 1.65 and 2 at 550 nm, see in all the visible, preferably the distance B between strands is less than or equal to 50 microns, more preferably less than or equal to 30 microns,
• the strands are of non-colored reflection metal (white metal), preferably silver and aluminum or platinum, chromium, palladium and nickel.
• white metal preferably silver and aluminum or platinum, chromium, palladium and nickel.
• a filler material of index at least greater than or equal to the index of the active OLED system typically of optical index of the order of 1.7 to 1.9
• minus 0.05 is chosen.
• a low-absorbency filling material in particular with a visible absorption of less than 10 -2 cm -1, is preferred.
• top filling material of inorganic index one can choose for example a deposit based on metal oxide as already indicated especially based on ZrO 2 , TiO 2 , Al 2 O 3 , Ta 2 O 5 . These oxides can be deposited under vacuum or preferably by liquid means. It can act from soil gels.
• a high sol-gel-type fill material mention may be made of hybrid gel sol layers obtained from metal precursors complexed with stabilizing agents. For example, layers obtained from solutions of zirconium propoxide or titanium butoxide complexed with acetylacetone in alcohol medium.
• such a material consists of a metal oxyhydroxide complexed by organic molecules.
• the organic functions can be eliminated by heat treatment from 350 ° C. to obtain inorganic gel sol layers.
• a high-index inorganic filler it is also possible to choose a high-index glass frit (lead-glass with bismuth, etc.), for example deposited by screen printing, by liquid spraying.
• polymers poly (1-naphthyl methacrylate-co-glycidyl methacrylate), with 10 mol% of glycidyl methacrylate, poly (2,4,6-tribromophenyl methacrylate), poly ( 2,4,6-tribromophenyl methacrylate-co-glycidyl methacrylate) with 10 mol% glycidyl methacrylate, poly (2,6-dichlorostyrene), poly (2-chlorostyrene), poly (2-vinylthiophene), poly (bis (4-iodophenoxy) phosphazene), poly (N-vinylphthalimide), poly (pentabromobenzyl acrylate), poly (pentabromobenzyl methacrylate), poly (pentabromobenzyl methacrylate-co-glycidyl methacrylate) with 10 mol% of glycidyl methacrylate, poly (2,4,6-tribromoph
• a high-index filler is to choose transparent materials with high index particles, polymeric or inorganic, in the high index materials already mentioned above, for example one chooses particles in ZrO 2 , TiO 2 , SnO 2 , AI 2 O 3 .
• inorganic transparent material it is possible to choose a glass frit.
• Sol-gel-type transparent material may be chosen from silica prepared from tetraethoxysilane (TEOS), sodium, lithium or potassium silicate, or hybrid obtained from organosilane precursors whose general formula is: R2 n Si (OR1) 4-n with n an integer between O and 2, R1 an alkyl function of type C x H 2x + I, R2 an organic group comprising, for example, an alkyl, epoxy, acrylate, methacrylate, amine or phenyl function, vinyl.
• TEOS tetraethoxysilane
• R1 an alkyl function of type C x H 2x + I
• R2 an organic group comprising, for example, an alkyl, epoxy, acrylate, methacrylate, amine or phenyl function, vinyl.
• These hybrid compounds can be used mixed or alone, in solution in water or in a water / alcohol mixture at an appropriate pH.
• silicones epoxy resins, polyurethanes PU, ethylene vinyl acetate EVA, polyvinyl butyral PVB, polyvinyl acetate PVA, and acrylics can be selected.
• the filling material is diffusing, in particular based on diffusing particles.
• Diffuse filler material having a blur greater than 5% may be preferred.
• the diffusing particles may be dispersed in a binder in proportions of 1 to 80% by weight of the mixture. These particles may have an average size greater than 50 nm and submicron, preferably between 100 and 500 nm, or even between 100 and 300 nm.
• the index of the diffusing particles may advantageously be greater than 1.7 and that of the binder be preferably less than 1.6, for example silica or an organosilicon hybrid material.
• the diffusing particles may be organic, for example in the above-mentioned high-index polymeric material.
• these diffusing particles may be inorganic, preferably nitrides, carbides or oxides, the oxides being chosen from alumina, zirconia, titanium or cerium or being a mixture of at least two of these oxides.
• the binder of the diffusing filling material may be preferably selected from essentially mineral binders, such as potassium silicates, sodium silicates, lithium silicates, aluminum phosphates, silica, and glass frits .
• organosilane binders as described above for transparent materials.
• the diffusing filling material may be deposited by any layer deposition technique known to those skilled in the art, in particular by screen printing, by coating with a paint, by dipping, by spin-coating, by spraying, or still by casting or flow-coating.
• This diffusing filler layer makes it possible to increase the efficiency of the OLED, in particular for relatively large strand distances, ie from 30 ⁇ m and even more at 100 ⁇ m and beyond.
• the diffusing filling material can only partially fill the space, in particular being in the lower part of the space between the network.
• the diffusing filling material is insulating. Its thickness may then be preferably between 20% and 100% of the height of the conductive strands and advantageously between 50% and 100% of the thickness of the strands.
• Filling of the melted glass frit or a sol gel layer may be chosen.
• the sol-gel fill layer can comprise as essential constituent material at least one compound of at least one of the elements: Si, Ti, Zr, Sb, Hf, Ta, Mg, Al, Mn, Sn, Zn, Ce. It may be in particular a simple oxide or a mixed oxide of at least one of the aforementioned elements.
• the filling material may preferably be essentially based on silica, in particular for its adhesion and compatibility with a mineral glass.
• the precursor sol of the material constituting the silica layer may be a silane, especially a tetraethoxysilane (TEOS) and / or a (methyltriethoxysilane) MTEOS, or a lithium, sodium or potassium silicate.
• the silica may be hybrid obtained by or a compound of general formula R2 n Si (OR1) 4-n as already mentioned above.
• the filling material preferably can be deposited preferably by screen printing, dipping, or liquid spraying.
• the overlying conductive coating may preferably be deposited by printing, such as by flexography, dipping, or liquid spraying.
• the mask can be preserved with a network of self-generated openings and the strands fill, preferably entirely, the network openings of the mask, the filling material then corresponding to this mask.
• This mask may preferably be surfaceable, in particular by mechanical polishing, preferably up to the level of the surface of the strands. The polishing may also make it possible, if necessary, to remove conductive material on the surface of the mask resulting from a non-selective deposition of the material for the network conductor. By polishing, it may optionally choose to deposit the electroconductive coating by gaseous, chemical or physical.
• a sol gel mask preferably based on silica, with a thickness that may exceed one to several microns, is chosen.
• It may be in particular a mineral silica gel sol layer obtained from lithium potassium silicate, or sodium.
• hybrid compounds can be used mixed or alone, in solution in water or in a water / alcohol mixture at an appropriate pH.
• the control of the concentration and drying conditions of the mask make it possible to modulate the ratio B / A.
• the electroconductive network may be composite, in particular multilayer.
• the electroconductive network may comprise or consist of an inexpensive and easy to manufacture metal oxide layer, for example zinc oxide ZnO, or tin oxide SnO 2 , or alternatively mixed oxide of indium and tin ITO.
• metal oxides are for example deposited by vacuum deposition, magnetron sputtering or ion beam assisted sputtering.
• the electroconductive network may be based on a pure metallic material selected from silver, aluminum or even platinum, gold, copper, palladium, chromium or based on said alloy material or doped with at least another material: Ag, Au, Pd, Al, Pt, Cu, Zn, Cd, In, Si, Zr, Mo, Ni, Cr, Mg, Mn, Co, Sn.
• the electroconductive network may comprise or consist of a layer of material (continuous medium) substantially metallic and / or a layer based on metal particles dispersed in an electroconductive matrix or not, for example an ink charged with conductive particles , in particular silver, such as the product TEC-PA-030® marketed by the company InkTec which can be deposited by scraping.
• the metal deposit or deposits may be supplemented by an electrolytic refill using an electrode Ag, Cu, Gold, or other high conductivity metal usable.
• Strands may be multilayer, in particular a first metal layer made of the abovementioned materials, in particular silver, aluminum, optionally topped with copper, and an overcoat for protection against corrosion (water and / or air), for example metallic, in nickel, chromium, molybdenum, or their mixtures, or even oxides TCO for example, of thickness from 10 nm, typically between 20 and 30 nm, and for example up to 200 nm or even 100 nm.
• the overcoat is deposited by evaporation or spraying.
• the composite electrode according to the invention may be essentially mineral, even more preferentially, the substrate is also glass.
• the substrate may be flat or curved, and further rigid, flexible or semi-flexible.
• This substrate may be large, for example, top surface to 0.02 m 2, or even 0.5 m 2 or 1 m 2 and a lower electrode substantially occupying the surface
• the substrate may be substantially transparent, mineral or plastic such as PC polycarbonate or polymethyl methacrylate PMMA or PET, polyvinyl butyral PVB, PU polyurethane, polytetrafluoroethylene PTFE etc ...
• the substrate is preferably glass, in particular of silicosodocalcic glass.
• the substrate may advantageously be a glass having an absorption coefficient of less than 2.5 m "1, preferably less than 0.7 m" 1 at the wavelength of the radiation or OLEDs.
• silicosodocalcic glasses with less than 0.05% Fe III or Fe 2 O 3 are chosen, for example Saint-Gobain Glass, Optiwhite glass,
• the thickness of the substrate in particular chosen glass, may be at least 0.35 mm, preferably at least 0.7 mm.
• edges of the wafer of the substrate may also be reflective, and preferably comprise a mirror, to ensure optimum recycling of the guided radiation and the edges, form with the main face associated with the OLED system an external angle greater than or equal to 45 ° and less than 90 °, preferably greater than or equal to 80 °, to redirect the radiation over a wider extraction zone.
• the slice can be as well beveled.
• the method of manufacturing the electrode described in document US Pat. No. 7,172,822 necessarily requires the deposition of an modifiable under-layer at the level of the cracks in order to allow the grafting of catalyst for a post-growth of metal. layer thus having a functional role in the growth process of the network.
• This underlayer may also have one or more of the following disadvantages: low adhesion to a soda-lime glass substrate, instability in a basic medium, widely used during washing of the substrates, instability during thermal treatments at high temperature (quenching, annealing etc).
• the composite electrode according to the invention may preferably be directly on the substrate, in particular glass.
• the composite electrode according to the invention may be discontinuous, typically forming at least two isolated electrode regions, one of which the other, and preferably one or more parallel rows of composite electrode areas.
• the composite electrode is etched by laser and the created void is filled with a passivation material, for example polyamide.
• the carrier substrate of the composite electrode as defined above may further comprise an organic electroluminescent system deposited directly on the outer surface.
• the invention also relates to an organic electroluminescent device incorporating the carrier substrate of the composite electrode as defined above, the composite electrode forming the so-called lower electrode, the closest to the substrate.
• the organic electroluminescent device may include:
• a discontinuous upper electrode with an electroconductive layer in the form of electrode zones arranged on the electroluminescent layer areas.
• the electroluminescent layer areas may be shifted from the lower electrode areas in the row direction and in a given direction, and the upper electrode areas may be shifted from the electroluminescent areas in the direction of the row and in the same direction.
• the distance between the electroluminescent zones of distinct rows may be greater than the distance between the zones of the same row, preferably from 100 ⁇ m, in particular between 100 ⁇ m and 250 ⁇ m.
• Each row is thus independent. If one of the zones in each row is defective, the entire row still works. And the adjacent rows are intact.
• the organic electroluminescent device according to the invention can be supplied with or without the current leads.
• Two continuous or discontinuous current supply strips forming part of a collector or a current distributor may respectively be electrically connected to a peripheral edge of the lower composite electrode, and with a peripheral edge of the upper electrode.
• These current feed strips may preferably be between 0.5 to 10 ⁇ m thick and 0.5 mm wide and may be in various forms:
• metal monolayer of one of the following metals Mo, Al, Cr, Nd or alloy of metals such as MoCr, AINd,
• a metal multilayer from the following metals: Mo, Al, Cr, Nd, such as MoCr / Al / MoCr,
• the upper electrode it is possible to use a thin metal layer known as "TCC” (for "transparent conductive coating” in English), for example in Ag, Al, Pd, Cu, Pd, Pt In or Mo, Au and, typically, thickness between 5 and 50 nm depending on the transmission / desired light reflection.
• TCC transparent conductive coating
• the upper electrode may be an electroconductive layer advantageously chosen from metal oxides, in particular the following materials: doped zinc oxide, especially aluminum ZnO: Al or gallium ZnO: Ga, or else indium oxide doped, in particular with tin
• ITO indium oxide
• IZO zinc doped indium oxide
• TCO Transparent Conductive Oxide
• the OLED device can produce monochromatic light, especially blue and / or green and / or red, or be adapted to produce white light.
• monochromatic light especially blue and / or green and / or red
• white light can be adapted to produce white light.
• the OLED device may include a plurality of adjacent organic electroluminescent systems, each of which is a light emitter white or, in sets of three, red, green and blue light, the systems being for example connected in series.
• Each row can for example emit according to a given color.
• the OLED device can be part of a multiple glazing, including a vacuum glazing or with air knife or other gas.
• the device can also be monolithic, include a monolithic glazing to gain compactness and / or lightness.
• the OLED system may be glued or preferably laminated with another flat substrate said cover, preferably transparent such as a glass, using a lamination interlayer, in particular extraclair.
• the laminated glazings usually consist of two rigid substrates between which is disposed a sheet or a superposition of polymer sheets of the thermoplastic type.
• the invention also includes so-called "asymmetrical" laminated glazings using a particularly rigid carrier substrate of the glass type and as a substrate covering one or more protective polymer sheets.
• the invention also includes laminated glazings having at least one interlayer sheet based on a single or double-sided adhesive polymer of the elastomer type (that is to say not requiring a lamination operation in the conventional sense of the term, laminating imposing heating generally under pressure to soften and adhere the thermoplastic interlayer sheet).
• the means for securing the cover and the carrier substrate may then be a lamination interlayer, in particular a sheet of thermoplastic material, for example polyurethane (PU), polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), or resin multi-component or multi-component heat-curable (epoxy, PU) or ultraviolet (epoxy, acrylic resin). It is preferably (substantially) of the same size as the cover and the substrate.
• the lamination interlayer may make it possible to prevent bending of the bonnet, particularly for devices of large dimensions, for example with an area greater than 0.5 m 2 .
• EVA offers many advantages: - it is not or little loaded with water in volume,
• thermoplastic lamination interlayer may be preferred to a cast resin cover because it is both easier to implement, more economical and possibly more watertight.
• the interlayer optionally comprises a network of electroconductive son embedded in its so-called internal surface facing the upper electrode, and / or an electroconductive layer or electroconductive strips on the inner surface of the cover.
• the OLED system can be preferably placed inside the double glazing, with a particularly inert gas blade (argon for example).
• argon for example
• a coating having a given functionality on the opposite side of the carrier substrate of the electrode according to the invention or on an additional substrate. It may be an anti-fog layer (using a hydrophilic layer), antifouling (photocatalytic coating comprising at least partially crystallized TiO 2 in anatase form), or an anti-reflection stack type for example
• 3 NVSiO 2 ZSi 3 NVSiO 2 or a UV filter such as a layer of titanium oxide (TiO2). It may also be one or more phosphor layers, a mirror layer, at least one diffusing layer of light extraction.
• the invention also relates to the various applications that can be found in these OLEDS devices, forming one or more transparent and / or reflecting luminous surfaces (mirror function) arranged both outside and inside.
• the device can form (alternative or cumulative choice) an illuminating, decorative, architectural, (etc.) system, a signaling display panel - for example of the drawing, logo, alphanumeric signage type, in particular an emergency exit sign -.
• the OLED device can be arranged to produce a uniform light, especially for uniform illumination, or to produce different light areas of the same intensity or distinct intensity. Conversely, one can seek a differentiated lighting.
• the organic electroluminescent system (OLED) produces a direct light region, and another light zone is obtained by extraction of OLED radiation which is guided by total reflections in the thickness of the selected glass substrate. To form this other light zone, the extraction zone may be adjacent to the OLED system or on the other side of the substrate.
• the extraction zone (s) can be used, for example, to reinforce the illumination provided by the direct light zone, in particular for an architectural type of lighting, or to signal the luminous panel.
• the extraction zone or zones are preferably in the form of band (s) of light, in particular uniform (s), and preferably arranged (s) on the periphery of one of the faces. These strips can for example form a very bright frame.
• the extraction is obtained by at least one of the following means arranged in the extraction zone: a diffusing layer, preferably based on mineral particles and preferably with a mineral binder, the substrate made diffusing, in particular texture or rough.
• the two main faces may each have a direct light area.
• an illuminating window can in particular be produced.
• the device in particular transparent by part (s) or entirely, can be:
• an external luminous glazing such as an external luminous glazing, an internal light partition or a part (part of) luminous glass door in particular sliding,
• a transport vehicle such as a luminous roof, a (part of) side light window, an internal light partition of a land, water or air vehicle (car, truck train, plane, boat etc),
• - intended for street or professional furniture such as a bus shelter panel, a wall of a display, a jewelery display or a showcase, a wall of a greenhouse, an illuminating slab, interior furniture, shelf or furniture element, furniture front, illuminated tile, ceiling lamp, illuminated refrigerator shelf, aquarium wall,
• For the backlight of electronic equipment including display screen or display, possibly dual screen, such as a TV screen or computer, a touch screen.
• one of the electrodes may be reflective or a mirror may be disposed on the opposite side of the OLED system, if it is desired to favor illumination of only one side in the direct light region.
• the illuminated panel can be used for lighting a bathroom wall or a kitchen worktop, to be a ceiling lamp.
• OLEDs are generally dissociated into two major families depending on the organic material used.
• SM-OLEDs Small Mollecule Organic Light Emitting Diodes
• the organic electroluminescent material of the thin layer consists of evaporated molecules such as for example the complex of AIQ 3 (tris (8-hydroxyquinoline) aluminum), DPVBi (4,4 '- (diphenylvinylene biphenyl)), the
• DMQA dimethyl quinacridone
• DCM dimethyl-6- (4-dimethylaminostyryl
• the emitting layer may also be for example by a layer of 4,4 ', 4 f '-tri (N-carbazolyl) TRIPHENYLAMINE (TCTA) doped with fac tris (2-phenylpyridine) iridium [Ir (ppy) 3].
• TCTA N-carbazolyl
• fac tris (2-phenylpyridine) iridium [Ir (ppy) 3].
• the structure of an SM-OLED consists of a hole injection layer stack or "HIL" for "HoIe Injection
• hole injection layer is copper phthalocyanine (CuPC)
• the hole-transporting layer may be, for example, N, N'-Bis (naphthalen-1-yl) -N, N'-bis ( phenyl) benzidine (alpha-NPB).
• the electron transport layer may be composed of tris (8-hydroxyquinoline) aluminum (Alq 3 ) or bathophenanthroline (BPhen).
• the upper electrode may be a Mg / Al or Li F / Al layer.
• organic electroluminescent stacks are for example described in US 6,645,645.
• organic electroluminescent layers are polymers, they are called PLED (Polymer Light Emitting Diodes).
• the organic electroluminescent material of the thin layer consists of these polymers (pLEDs), for example PPV for poly (para-phenylene vinylene), PPP (poly (para-phenylene), DO-PPP
• polymer layer is also associated with a layer which promotes the injection of holes ( HIL) consisting for example of PEDT / PSS (poly (3,4-ethylene-dioxythiophene / poly (4-styrene sulfonate).
• HIL hole-initiol
• PEDOT poly(styren sulphonate)
• the invention also relates to the method of manufacturing the composite electrode on the carrier substrate as defined above comprising, in a first configuration, the following steps: a first step of directly forming the driver's network arrangement, comprising at least one of the following depots:
• a deposit of the electroconductive material of the network by ink-pad or conductive ink jet on the substrate a deposit in an etching network of the substrate, preferably glass.
• a second step comprising a liquid deposit of the electroconductive coating.
• a second step comprising a liquid deposit of the electroconductive coating.
• the deposition of the electroconductive material of the network in the mask and / or in the etching network may preferably be achieved by a simple, non-selective deposition, preferably by vacuum deposition, in particular by evaporation, or by liquid, especially by scraping a conductive ink, by dipping, by printing (flat or rotary)
• This deposit is optionally supplemented by an electrolytic charging by a metal such as gold, silver, copper.
• the method according to the invention comprises a step of forming the mask comprising: depositing on the substrate (bare or coated) a so-called masking layer,
• the firing that is to say a drying if the layer is liquid
• the masking layer may advantageously be a solution of colloidal particles stabilized and dispersed in a solvent, in particular an aqueous solution of colloids based on acrylic copolymers.
• Such an array of openings has significantly more interconnections than the fissured silica gel ground mask.
• the mask thus has a random, aperiodic structure on at least one direction, or even two (all) directions.
• the width (average) of the micron or even nanometric network A in particular between a few hundred nanometers to a few tens of micrometers, in particular between 200 nm and 50 ⁇ m,
• - size (average) pattern B millimeter or submillimeter, in particular between 5 to 500 microns, or even 100 to 250 microns,
• the open mesh rate (non-emerging gap, "blind"), is less than 5%, or even less than or equal to 2%, in a given region of the mask, or even on the majority or the entire surface, therefore with a rupture limited network see almost zero, possibly reduced, and deleted by burning the network, for a given mesh, the majority or even all the meshes, in a given region or on the whole surface, the difference between the greatest characteristic dimension of mesh and the smallest characteristic dimension of mesh is less than 2, to reinforce the isotropy, - for the majority or all segments of the network, the edges are constant spacing, parallel, especially at a scale of 10 microns (for example observed under an optical microscope with a magnification of 200).
• the width A may be for example between 1 and 20 microns, even between 1 and 10 microns, and B between 50 and 200 microns. This makes it possible subsequently to produce a grid defined by an average strand width substantially identical to the width of the openings and a (mean) space between the strands substantially identical to the space between the openings (of a mesh).
• the sizes of the strands may preferably be between a few tens of microns to a few hundred nanometers.
• the ratio B / A can be chosen between 7 and 20, or even 30 to 40.
• the meshes delimited by the openings are of various shapes, typically three, four, five sides, for example mainly four sides, and / or of various sizes, randomly distributed, aperiodic.
• the angle between two adjacent sides of a mesh can be between 60 ° and 110 °, in particular between 80 ° and 100 °.
• a main network is obtained with openings (possibly approximately parallel) and a secondary network of openings (possibly approximately perpendicular to the parallel network), whose location and distance are random.
• the secondary openings have a width for example less than the main openings.
• the drying causes a contraction of the mask layer and a friction of the nanoparticles at the surface inducing a tensile stress in the layer which, by relaxation, forms the openings.
• the solution is naturally stable, with nanoparticles already formed, and preferably does not contain (or in negligible amount) polymer-precursor type reactive element. Drying leads in one step to the removal of the solvent and the formation of the openings.
• particles of limited size nanoparticles
• dispersion with preferably a characteristic (average) dimension between 10 and 300 nm, or even 50 and 150 nm, of stabilizing the particles in the solvent (in particular by treatment with surface charges, for example by a surfactant, by control of the pH), to prevent them from agglomerating with each other, that they precipitate and / or that they fall by gravity.
• the concentration of particles is adjusted, preferably between 5% and even 10% and 60% by weight, more preferably between 20% and 40%.
• the addition of binder is avoided.
• the solvent is preferably water-based or even entirely aqueous.
• the colloid solution comprises polymeric nanoparticles (and preferably with a water-based or even entirely aqueous solvent).
• polymeric nanoparticles and preferably with a water-based or even entirely aqueous solvent.
• acrylic copolymers, styrenes, polystyrenes, poly (meth) acrylates, polyesters or mixtures thereof are chosen.
• the solution comprises mineral nanoparticles, preferably silica, alumina, iron oxide.
• deposition and drying can preferably be carried out at a temperature below said temperature Tg for better control of the morphology of the grid mask.
• the deposition and drying steps of the process may in particular be carried out (substantially) at room temperature, typically between 20 ° and 25 ° C. Annealing is not necessary.
• the difference between the glass transition temperature Tg given particles and the drying temperature is preferably greater than 10 0 C or 20 0 C.
• the deposition and drying steps of the process can be carried out substantially at atmospheric pressure rather than vacuum drying for example.
• the drying parameters can be modified to adjust B, A, and / or the B / A ratio.
• the ratio B / A can be adjusted.
• edges of the mask are substantially straight, that is to say in a mean plane between 80 and 100 ° relative to the surface, or even between 85 ° and 95 °.
• the deposited layer is discontinuous (no or little deposit along the edges) and the coated mask can thus be removed without damaging the grating.
• the deposited layer can be made both through the interstices and on the mask.
• the openings in the network may be cleaned prior to the development of the first deposition step, preferably using a plasma source at atmospheric pressure.
• the surface for the deposition of the mask layer based on colloids is film-forming, especially hydrophilic if the solvent is aqueous.
• This sub-layer is not necessarily a growth layer for electrolytic deposition of the gate material. Between the mask layer there can be several sub-layers.
• the substrate according to the invention may thus comprise an underlayer (in particular as a base layer, the closest to the substrate), which is continuous and may be an alkaline barrier.
• the basecoat is robust, easy and fast to deposit according to different techniques. It can be deposited, for example by a pyrolysis technique, especially in the gas phase (a technique often referred to by the abbreviation of C.V. D, for "Chemical Vapor Deposition"). This technique is interesting for the invention because appropriate settings of the deposition parameters make it possible to obtain a very dense layer for a reinforced barrier.
• the primer may be optionally doped with aluminum and / boron to make its vacuum deposit more stable.
• the bottom layer (monolayer or multilayer, possibly doped) may be between 10 and 150 nm thick, more preferably between 15 and 50 nm.
• the bottom layer may be preferably: based on silicon oxide, silicon oxycarbide, layer of general formula SiOC, based on silicon nitride, silicon oxynitride, silicon oxycarbonitride, layer of general formula SiNOC, in particular SiN, in particular Si 3 N 4 .
• a bottom layer based on silicon oxide, silicon oxycarbide, layer of general formula SiOC, based on silicon nitride, silicon oxynitride, silicon oxycarbonitride, layer of general formula SiNOC, in particular SiN, in particular Si 3 N 4 .
• silicon nitride Si 3 N 4 / doped or not. Silicon nitride is very fast to deposit and forms an excellent barrier to alkalis.
• the second deposition step it is possible, before the second deposition step, to provide a removal step preferably by liquid means, for example by selective chemical dissolution of the mask (in water, alcohol, acetone, acidic or basic solutions). , optionally hot and / or ultrasonically assisted, to reveal said electroconductive network.
• a removal step preferably by liquid means, for example by selective chemical dissolution of the mask (in water, alcohol, acetone, acidic or basic solutions).
• the second deposition step it is possible, before the second deposition step, to provide for a removal step, for example by selective chemical dissolution of the mask (in water, alcohol, acid or basic solutions), until revealing said electroconductive network.
• the first configuration or the second configuration after removal of the mask to reveal said electroconductive network, it can provide a deposit of a lower thickness filling material.
• This filler may be optionally also diffusing, high index, and the materials already described, in particular be a sol-gel layer.
• the deposition can be carried out for example by printing, by screen printing, by scraping an ink, by dipping, by liquid spraying, depending on the chosen materials and formulations.
• first configuration or the second configuration after removal of the mask until revealing said electroconductive network
• This surfaceable filler layer can be screen printed by example of the glass frit, or be a preferably transparent gel sol layer, for example a mineral or hybrid silica layer already described.
• the filler layer is insulating, the surfacing must naturally make it possible to discover the surface of the strands for electrical contact with the overlying electroconducting coating.
• the heat treatment serves, for example, to melt the glass frit or, for the sol-gel layer, to remove the solvent and / or to densify the layer.
• the heat treatment serves, for example, to melt the glass frit or, for the sol-gel layer, to remove the solvent and / or to densify the layer.
• the second deposition step can even be by a step of deposition by gaseous means, by spraying in particular of a simple, doped and / or mixed conductive metal oxide such as those already described.
• a mechanical polishing step can be provided to obtain an electroconductive network and a mask of the same height and with a surface smooth before the second deposit step.
• the second deposition step can even be by a step of deposition by gaseous route, by spraying in particular of a simple, doped and / or mixed conductive metal oxide such as those already described.
• the composite electrode, at least the electroconductive coating is resistant to the following OLED manufacturing steps: held at 200 ° C. for 1 hour,
• FIG. 1 is a diagrammatic sectional view of a first organic electroluminescent device, which comprises a composite lower electrode according to a first embodiment of the invention
• FIG. 2 illustrates a schematic top view of the electrode array used in the device of FIG. 1;
• FIG. 3 is a schematic sectional view of a second organic electroluminescent device, which comprises a composite lower electrode according to FIG. a second embodiment of the invention,
• FIG. 4 is a diagrammatic sectional view of a third organic electroluminescent device, which comprises a composite lower electrode according to a third embodiment of the invention.
• FIG. 1 voluntarily very schematic, shows in lateral section an organic electroluminescent device 100 (emission through the substrate or "bottom emission” in English).
• This device 100 comprises a plane substrate 1 made of clear, for example rectangular, 0.75-mm thick silico-soda-lime glass with first and second main faces 11, 12.
• the first main face 11 comprises:
• an organic electroluminescent system 3 for example an SM-OLED of following structure:
• a reflective upper electrode 4 in particular metal in particular based on silver or aluminum.
• the composite lower electrode 2 comprises first an aperiodic network conductor 21, 1 ⁇ m thick, formed of irregular strands based on silver, average width A of the order of 3 microns, and spaced between they have an average distance B of the order of 30 ⁇ m, with a B / A ratio of 10.
• the square resistance of this network 21, particularly low is about 0.6 Ohm / square.
• the light transmission T L of this network 21 is about 70% and the strands are invisible to the naked eye.
• it can deposit on the metal strands a protective overlay of nickel or chromium with a thickness of about ten nm, thereby forming composite strands.
• a high-index filler layer 23 is used, formed of nanoparticles of TiO 2 with a size of less than 50 nm.
• This layer 23 may be deposited with a solvent which is then evaporated. This layer 23 improves the extraction of the guided modes in the organic layers.
• the electroconductive coating 22 in PEDOT / PSS deposited by liquid route is resistivity pi of the order of 10 "1 Ohm. Cm, a thickness of the order of 100 nm, fills the remaining space and smooth the electrode 2.
• the electroconductive network 21 is manufactured by silver evaporation on a mask with a network of self-organized openings. The mask is removed afterwards. The irregular arrangement of the electroconductive network 21 with its strands 210 is shown in FIG.
• an opening of the composite electrode 2 near a longitudinal edge and preferably over its entire length is made for example by laser and is about 150 microns wide.
• This etched area is then passivated by means of an insulating resin 5 of acrylic type.
• bus bars 6 In electrical junction zones, provided here near the longitudinal edges, it is preferred to add conventional bus bars 6 by example by silkscreening silver on the electrodes 2, 4.
• the device 100 produces a uniform illumination on a surface that can be large. If it is desired to create a plurality of light zones, other suitable laser etchings, for example 150 ⁇ m wide, are made at the time of etching for the connection, and then passively.
• Fig. 3 shows a sectional view of an organic electroluminescent device 3200 which comprises a composite electrode 2. Only the modifications with respect to the device 100 are detailed below.
• a filler layer 230 made of molten glass frit is interposed between the strands of the network 210 .
• the surface formed by the strands of the network 210 and the molten glass frit 230 is smoothed by mechanical polishing using, for example, polishing with alumina, or cerium oxide, etc.
• This glass frit can alternatively be high index.
• glass frit is deposited between the strands of the network 210 and beyond to form an overlayer on the strands. After annealing, the surface is then leveled to the level of the strands.
• a sol-gel layer may be chosen as a filler layer, for example a hybrid silica layer obtained from a soil composed of methyltriethoxysilane (MTEOS).
• MTEOS methyltriethoxysilane
• MTEOS methyltriethoxysilane
• 3 moles of water and 3 moles of ethanol are added.
• the formulation is preferably deposited by dipping or liquid spraying. The deposited formulation is dried at 100 ° C. and then undergoes a heat treatment for one hour at 450 ° C. It is preferable to choose to deposit the formulation in overcoat, and after drying and annealing, to polish the sol-gel layer, leveling the surface to the level of the strands.
• This gel sol layer can be high index for example by being loaded with ZrO 2 . Since the filler layer 230 is insulating, the electroconductive coating 220 with a low resistivity is chosen. The electroconductive coating 220 preserves the smoothing and distributes the current.
• the electroconductive coating 220 By polishing, it is possible to choose to deposit the electroconductive coating 220 by gas deposition.
• ITO sputtering is chosen to obtain a pI resistivity of the order of 10.sup.- 4 ohm.cm, with a thickness starting from 40 nm.An ITO sol-gel layer can also be formed.
• the electroconductive coating may alternately be
• polished glass frit is not used because a network mask of self-organized openings, typically cracks, is used to fabricate the network of the electrode. It is a solid and polished monolithic mask for example a hybrid sol-gel layer.
• a silica layer obtained from a sol composed of triethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) is chosen in a molar ratio equal to 1.
• TEOS triethoxysilane
• MTEOS methyltriethoxysilane
• the mass concentration of precursors is 45%.
• the formulation is preferably deposited by dipping or liquid spraying.
• the formulation is directly subjected to a high temperature heat treatment, for example one hour at 450 ° C., to generate the cracks.
• a high temperature heat treatment for example one hour at 450 ° C.
• network-conducting material for example silver
• liquid for example by scraping an ink until a fraction of the height of the mask is filled. Then comes to polish the surface of the mask by polishing up to the level of the strands.
• Fig. 4 shows a sectional view of an organic electroluminescent device 300 which comprises a composite electrode 20 '. Only modifications with respect to the device 100 are detailed below.
• the electroconductive network 210 ' is in an etching network 110 of the glass 1, a micron thick.
• a cracked sol-gel mask is used on the glass, for example based on hybrid or non-hybrid silica.
• the substrate is etched wet with an HF solution.
• the deposition of the material of the network is carried out keeping the mask sol gel, the deposit being made through cracks.
• Vacuum deposition is preferably chosen, for example a deposit of silver by evaporation or a deposition of ITO or IZO by spraying.
• the deposit thickness can be controlled to preferably completely fill the etched areas.
• the glass is then polished to remove the electroconductive deposit on its free surface.
• the electroconductive coating 220 ' may be, for example, PEDOT / PSS deposited by a thick liquid process starting at 50 nm.
• the outer surface of the coating is such that, starting from a so-called real profile of the external surface over the average period of the B + A grating and forming a profile corrected by nanometric filtering to eliminate the local microroughness, at any point of the corrected profile, an angle formed by the tangent to the corrected profile is obtained with the average plane of the corrected profile less than or equal to 45 °.
• a maximum altitude difference between the highest point and the lowest point of the residual profile in the corrected profile is obtained at any point in the corrected profile. less than 50 nm over the average period of the B + A network.
• the so-called masking layer incorporating the colloidal particles is then dried so as to evaporate the solvent.
• This drying can be carried out by any suitable method (hot air drying
• the system self-arranges and describes patterns according to a structure characterized by the average width of the pattern referred to as A1 and the mean distance between the patterns referred to below as Bl.
• This stabilized mask will be subsequently defined by the ratio Bl / Al.
• a stable mask is obtained without annealing.
• the ratio B1 / A1 can be modified by adapting, for example, the coefficient of friction between the compacted colloids and the surface of the substrate, or the size of the nanoparticles, or even the rate of evaporation, or the initial concentration of particles, or the nature of the solvent, or the thickness depending on the deposition technique.
• a cleaning using a plasma source at atmospheric pressure, plasma blown based on a mixture of oxygen and helium allows both the improvement of the adhesion of the material deposited at the bottom of the interstices and widening of the interstices. It is possible to use a plasma source of "ATOMFLOW" brand marketed by the company Surfx.
• the electroconductive network of the composite electrode according to the invention is produced.
• the average width of the conductive strands A is substantially equal to Al.
• the average distance between the conductive strands B is substantially equal to B1.
• a "lift off” operation is carried out.
• the colloidal mask is immersed in a solution containing water and acetone (the cleaning solution is chosen according to the nature of the colloidal particles) and then rinsed so as to remove all the parts coated with colloids.
• the space between the conductive strands is completely filled by a given material preferably favoring the extraction of the guided modes in the OLED (high index, scattering) and / or electroconductive layers, and at the coverage of the network. by an electroconductive coating which completes the smoothing and has an electrical role of distributing the current or maintaining a vertical conductivity.

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