Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F12/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring
  • C08F12/02—Monomers containing only one unsaturated aliphatic radical
  • C08F12/04—Monomers containing only one unsaturated aliphatic radical containing one ring
  • C08F12/14—Monomers containing only one unsaturated aliphatic radical containing one ring substituted by hetero atoms or groups containing heteroatoms
  • C08F12/26—Nitrogen
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
  • C09K11/06—Luminescent materials, e.g. electroluminescent or chemiluminescent containing organic luminescent materials
• • 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
  • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
  • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
• • 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
  • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
  • H10K50/14—Carrier transporting layers

Definitions

• the invention relates to electroluminescent materials comprising electroluminescent polymers which can in particular be used in visualization.
• Electroluminescence based on the use of polymers appears today to be the technology capable of overcoming the shortcomings of cathode ray tubes. Indeed :
• electroluminescent screens require the use of very thin film material ( ⁇ 1 ⁇ m) and therefore leads to flat and light displays; the deposition of an electroluminescent polymer by centrifugation has the advantages of being inexpensive, of leading to curved screens (when flexible substrate is used) and of accessing large screens;
• the polymer is capable of being etched, which opens up many perspectives in the production of complex screens.
• electroluminescent screens offer a better angle of view, a simpler implementation (no alignment layer) and do not require backlighting.
• Conjugated polymers such as PPV and MEH-PPV are the most studied.
• - PPV is insoluble, which requires going through a soluble precursor to deposit a thin film and pyrolyzing the film at a temperature between 200 and 280 ° C under vacuum to obtain a thin layer of PPV;
• the invention relates to a new family of side chain electroluminescent copolymers designed to be stable over time and efficient in terms of electroluminescence properties. These copolymers correspond to the following chemical formula:
• GR is a crosslinkable group of the type
• the phenyl-tBu group blocks the molecule in a certain configuration and generates space in space. This then avoids too close proximity of the chromophores to each other and increases the photoluminescence yield.
• PVK polyvinylcarbazole
• the subject of the invention is also a material comprising a copolymer of the invention and molecules whose absorption spectrum at least partially covers the electroluminescence spectrum of the electroluminescent copolymer and whose emission spectrum is situated in wavelengths greater than said electroluminescence spectrum.
• These molecules can be of the type:
• the subject of the invention is also a light-emitting diode comprising a substrate covered with an anode, a first layer ensuring the transport of holes, a second layer comprising an electroluminescent copolymer according to the invention or an electroluminescent material comprising said copolymer, a third layer providing electron transport and a cathode.
• the materials constituting the first layer may be of the polyvinylcarbazole type or of the polymethylphenylsilane type or else of the crosslinkable copolymer type of the
• copolymers according to the invention can advantageously comprise a crosslinkable group.
• crosslinkable group is of the type:
• Crosslinking is ensured by simple heating or by adding molecules having several aliphatic amine functions to the coating solution, for example:
• crosslinkable group is of the type:
• crosslinking is obtained by adding molecules to the coating solution with several aliphatic amine functions, such as:
• crosslinkable group is of the type:
• crosslinking is carried out by adding molecules to the coating solution with several epoxy functions such as:
• crosslinkable group is of the type:
• the remaining amine and the quinoline are protonated by adding a solution of HCI diluted until an acidic pH is obtained.
• the precipitate is drained under vacuum on a buchner.
• the brown crystals obtained are dissolved in CHCl 3 with magnetic stirring.
• the whole is then poured into a separatory funnel.
• the organic phase is washed three times with a dilute HCl solution, then rinsed with water until the pH of the aqueous phase is neutral.
• the organic phase is dried over MgS ⁇ 4. is crystallized from ether.
• the solid is purified by chromatography on silica gel with chloroform as eluent.
• the output of the product is controlled by CCM.
• the pure fractions are collected.
• the product is crystallized from petroleum ether.
• the crystals are then wrung under vacuum on a buchner.
• the imide is then recrystallized from anhydrous ethanol with strong magnetic stirring overnight.
• the white crystals are filtered under vacuum.
• the product is purified by chromatography on silica gel, with
• the contents of the three-necked flask are poured into a beaker containing methanol in order to remove the remaining hydride.
• the addition of a large excess of water with stirring causes a strong emulsion which is broken with a small amount of diluted HCl.
• the brown paste obtained after vacuum filtration on a buchner is redissolved in CH2CI2.
• the whole is placed in a separating funnel.
• the aqueous phase is rinsed with CH2Cl2 and the organic phase is dried over MgS ⁇ 4.
• the ether is purified by chromatography on silica gel with CH2Cl2 as eluent.
• the output of the product is controlled by CCM.
• the pure fractions are passed through a rotary evaporator and the thick oil obtained is triturated in petroleum ether until it has completely crystallized.
• the vacuum-filtered product is then recrystallized from hexane, with magnetic stirring while heating to a minimum to avoid polymerization. The solution is left overnight in the freezer. 1]
• the polymer is then redissolved with stirring in approximately 5 ml of CH2Cl2, then precipitated again in methanol and filtered on a buchner before being placed under vacuum at room temperature to remove any possible trace of solvent.
• An anode of indium tin oxide is produced on a substrate.
• an oxygen plasma treatment can advantageously be done.
• This polymer can be of the polyaniline or polyethylenedioxythiophene-polystyrene sulfonate type.
• the deposition of the PVK type hole injector layer is then carried out.
• the coating conditions can typically be a concentration of the order of 10 g / l, a coating speed of 6000 rev / min, a duration of 30 s and an acceleration of 8000 rev / min / s.
• a solution containing the electroluminescent polymer is coated, with a concentration of the order of 20 g / l of toluene, a speed of 3000 rpm for 30 s and an acceleration of 8000 trs. / min / s.
• Figure 6 provides the evolution of the light output as a function of the applied voltage.
• Figure 7 provides the quantum efficiency as a function of the applied voltage, i.e. an EQE efficiency of 2.6% for a voltage of 8.4 V.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Electroluminescent Light Sources (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (3)

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• 1998
  • 1998-07-10 FR FR9808926A patent/FR2780979B1/fr not_active Expired - Fee Related
• 1999
  • 1999-07-02 WO PCT/FR1999/001600 patent/WO2000002936A1/fr not_active Ceased
  • 1999-07-02 EP EP99929385A patent/EP1102799A1/de not_active Withdrawn

Non-Patent Citations (1)

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