Source: http://www.google.com/patents/US5902689?dq=6,563,928
Timestamp: 2014-03-13 12:44:15
Document Index: 775800612

Matched Legal Cases: ['arts 52', 'arts 51', 'arts 51', 'arts 52', 'arts 51', 'arts 52', 'arts 52', 'arts 51']

Patent US5902689 - Electroluminescent device - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA description is given of a method of providing an electroluminescent device (20) comprising an active layer (5) of conjugated 2,5-alkyl- or alkoxy-substituted poly(p-phenylene vinylene) with inactive regions (51) and emissive regions (52) by means of patterned irradiation with UV light. Both regions...http://www.google.com/patents/US5902689?utm_source=gb-gplus-sharePatent US5902689 - Electroluminescent deviceAdvanced Patent SearchPublication numberUS5902689 APublication typeGrantApplication numberUS 08/691,905Publication dateMay 11, 1999Filing dateAug 1, 1996Priority dateAug 3, 1995Fee statusLapsedAlso published asDE69605526D1, DE69605526T2, EP0784659A1, EP0784659B1, WO1997006223A1Publication number08691905, 691905, US 5902689 A, US 5902689A, US-A-5902689, US5902689 A, US5902689AInventorsAdrianus J. M. Berntsen, Robert J. C. E. Demandt, Coen T. H. F. Liedenbaum, Hermanus F. M. Schoo, Aemilianus G. J. Staring, Jeroen J. M. VleggaarOriginal AssigneeU.S. Philips CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (1), Non-Patent Citations (6), Referenced by (29), Classifications (21), Legal Events (6) External Links: USPTO, USPTO Assignment, EspacenetElectroluminescent deviceUS 5902689 AAbstract A description is given of a method of providing an electroluminescent device (20) comprising an active layer (5) of conjugated 2,5-alkyl- or alkoxy-substituted poly(p-phenylene vinylene) with inactive regions (51) and emissive regions (52) by means of patterned irradiation with UV light. Both regions (51) and (52) of the active layer (5) show a clear difference in electroluminescence, electrical resistance and solubility. By means of the above-described effects, displays can be manufactured without making use of structured electrode layers (3) and (11).
We claim: 1. An electroluminescent device comprising an active layer having an electroluminescent property, which layer includes 2,5-substituted poly(p-phenylene vinylene) and which is situated between two electrode layers, at least one of said electrode layers being transparent to the light to be emitted, and, in operation, said device exhibiting a light-emitting pattern, characterized in that the electroluminescent property of the active layer is substantially absent locally thereby providing said pattern.
BACKGROUND OF THE INVENTION The invention relates to an electroluminescent device comprising an active layer having an electroluminescent property, which layer includes 2,5-substituted poly(p-phenylene vinylene) and which is situated between two electrode layers, at least one of said electrode layers being transparent to the light to be emitted and, in operation, said device exhibiting a light-emitting pattern. The invention also relates to a method of manufacturing an electroluminescent (EL) device having a structured active layer.
OBJECTS AND SUMMARY OF THE INVENTION It is an object of the invention to provide, inter alia, a simpler EL device which, in operation, exhibits a light-emitting pattern and in which none of the electrodes has to be structured. The invention further aims at providing a simple method of manufacturing such an EL device.
The active layer preferably comprises poly(2,5-dialkyl-p-phenylene vinylene), poly(2,5-dialkoxy-p-phenylene vinylene) or corresponding cyano-PPVs. In these polymers a difference in electroluminescence of approximately a factor of 10.sup.5 can be attained. In addition, this difference is accompanied by a difference in specific resistance of the active layer of approximately a factor of 10.sup.2, i.e. when an electric field is applied across the active layer, the current runs predominantly through the regions having electroluminescent properties. Thus, the leakage current through non-electroluminescent regions is very small.
The UV light may originate, for example, from a mercury lamp which emits light having a wavelength of predominantly 365 nm. Patterned exposure can take place, for example, via a (shadow) mask. Dependent upon the layer thickness of the active layer and the power of the mercury lamp, an exposure time in the range from one to several minutes is sufficient to cause the electroluminescent properties of the active layer to disappear completely. In addition, said exposure to UV light causes the specific resistance of the exposed parts of the layer to increase by a factor of 10.sup.2.
Suitable 2,5-substituted PPV compounds for the method in accordance with the invention comprise one of the formulas (I) or (II) as the repeating unit: ##STR1## where R.sub.1 and R.sub.2 represent a C.sub.1 -C.sub.20 alkyl group or alkoxy group. The degree of polymerization of the conjugated polymer ranges between 10 and approximately 100,000. In view of the improved solubility of the conjugated PPV in organic solvents, the substituents R.sub.1 and R.sub.2 preferably have chains of unequal length. Said PPV compounds are readily soluble, namely 1 to 3 wt. %, in many organic solvents such as toluene, xylene, tetrahydrofuran and mixtures of these solvents, so that the active layer of the EL device can be manufactured, for example, by means of spin coating. The alkyl or alkoxy substituents R.sub.1 and R.sub.2 in said formulas may be unbranched or branched.
It has been found that the use of alkyl or alkoxy substituents which are longer than approximately C.sub.12 does not lead to a noticeable increase of their solubility in organic solvents; besides, the quantity of active material per gram of conjugated PPV decreases due to the presence of longer alkyl substitutents. As they exhibit a good solubility, preferably, branched alkyl or alkoxy substitutents R.sub.1 and R.sub.2 are used.
Suitable alkyl substitutents R.sub.1 are the 3,7-dimethyl octyl group (C.sub.10), the 4,6,6-trimethyl heptyl group (C.sub.10), the n-undecyl group (C.sub.11) and the n-dodecyl group (C.sub.12).
Suitable alkyl substitutents R.sub.2 are the methyl group C.sub.1, the ethyl group (C.sub.2), the propyl group (C.sub.3) and the n-butyl group (C.sub.4).
Suitable alkoxy substitutents R.sub.1 and R.sub.2 are, for example, the decyloxy group (OC.sub.10) and the methoxy group (OC.sub.1 or OCH.sub.3), respectively.
It is noted that in an article by P. L. Burn et al. in Nature, 356, 47-49 (1992) a description is given of a method in which a non-conjugated precursor polymer with methoxy as leaving group is thermally converted to a conjugated PPV compound at 220 eliminated in the presence of HCl and another PPV compound is formed. Patterned conversion takes place by locally covering a layer of the precursor polymer with vapour-deposited aluminium strips, heating said layer to 220 the aluminium. The regions of the PPV layer which were covered during the thermal treatment are of a different color during electroluminescence. In this manner patterns of differently colored electroluminescent regions can be manufactured. The known method is rather time-consuming and requires the presence of the corrosive HCl gas. In addition, when use is made of the known method, it is impossible to manufacture dark regions next to light-emitting regions.
A conjugated 2,5-dialkoxy-substituted PPV in which R.sub.1 =OC.sub.10 H.sub.21 and R.sub.2 =OCH.sub.3 (poly 2-methoxy-5-decyloxy-p-phenylene vinylene!: FIG. 1, formula (I)) is prepared by polymerization of 1,4-bischloromethyl-2-methoxy-5-decyloxy benzene. The preparation is described in the above-mentioned article by D. Braun et al., Synthetic Metals, 66 (1994) 75-79. The polymer obtained is readily soluble, inter alia, in toluene, tetrahydrofuran and xylene.
FIG. 3 shows the I-V characteristic of the EL device 20 obtained, in which the current I in ampere is plotted as a function of the applied voltage V in volt between the electrodes. Curve A shows the current I of the unexposed parts 52. Curve B shows the current of the parts 51 which are passivated by exposure to light. FIG. 3 shows that, at a constant voltage, the current decreases to maximally a factor of 10.sup.2 at voltages above 4 volts under the influence of the UV radiation. It is favorable that the passivated parts 51 of the active layer 5 have a higher specific resistance than the unexposed parts 52. By virtue thereof, the current density through the passivated parts 51 is much lower than in the emitting parts 52, so that the leakage current is small.
FIG. 4 shows the amount of light L (electroluminescence) in arbitrary units (a.u.) as a function of the voltage V in volt. Curve A applies to the unexposed parts 52, while curve B applies to the passivated parts 51. FIG. 4 shows that, at a constant voltage, the electroluminescence decreases by a factor of 10.sup.5 under the influence of the UV radiation.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleWO1990013148A1 *Apr 18, 1990Oct 21, 1990Cambridge Capital ManagementElectroluminescent devices* Cited by examinerNon-Patent CitationsReference1 *D. Braun et al., Synthetic Metals , 66 (1994) pp. 75 79.2D. Braun et al., Synthetic Metals, 66 (1994) pp. 75-79.3 *E.J.G. Staring et al, Advanced Materials , 1994, 6, No. 12,pp. 934 937.4E.J.G. Staring et al, Advanced Materials, 1994, 6, No. 12,pp. 934-937.5 *P. L. Burn et al. in Nature , 356, pp. 47 49 (1992).6P. L. Burn et al. in Nature, 356, pp. 47-49 (1992).* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6229266 *May 14, 1999May 8, 2001U.S. Philips CorporationVoltage level indicatorUS6285124 *Jan 6, 1999Sep 4, 2001Pioneer Electronic CorporationOrganic EL display panel having a conductive high polymer layer between an anode layer and an organic EL layerUS6495644 *Jan 11, 2000Dec 17, 2002National Science CouncilElectroluminiscent conjugated polymers modified with high electronegative heterocyclic moieties and their applications in polymeric light emitting diodesUS6582756 *Nov 21, 2000Jun 24, 2003Agilent Technologies, Inc.Method and apparatus for fabricating polymer-based electroluminescent displaysUS6693158 *Nov 15, 2002Feb 17, 2004National Science CouncilElectroluminiscent conjugated polymers modified with high electronegative heterocyclic moieties and their applications in polymeric light emitting diodesUS7087348Jan 30, 2003Aug 8, 2006A123 Systems, Inc.Coated electrode particles for composite electrodes and electrochemical cellsUS7318982Jun 23, 2004Jan 15, 2008A123 Systems, Inc.Polymer composition for encapsulation of electrode particlesUS7338734Dec 23, 2002Mar 4, 2008Massachusetts Institute Of TechnologyConductive lithium storage electrodeUS7387851Jan 30, 2003Jun 17, 2008A123 Systems, Inc.Self-organizing battery structure with electrode particles that exert a repelling force on the opposite electrodeUS7553584Oct 22, 2001Jun 30, 2009Massachusetts Institute Of TechnologyReticulated and controlled porosity battery structuresUS7579112Jul 26, 2002Aug 25, 2009A123 Systems, Inc.Battery structures, self-organizing structures and related methodsUS7662265Apr 18, 2005Feb 16, 2010Massachusetts Institute Of TechnologyElectrophoretic assembly of electrochemical devicesUS7763382Jul 28, 2003Jul 27, 2010A123 Systems, Inc.Bipolar articles and related methodsUS7781098Mar 3, 2008Aug 24, 2010Massachusetts Institute Of TechnologyReticulated and controlled porosity battery structuresUS7988746Sep 20, 2010Aug 2, 2011A123 Systems, Inc.Battery structures, self-organizing structures and related methodsUS8088512Jun 16, 2008Jan 3, 2012A123 Systems, Inc.Self organizing battery structure methodUS8148009Nov 30, 2010Apr 3, 2012Massachusetts Institute Of TechnologyReticulated and controlled porosity battery structuresUS8148013Sep 17, 2007Apr 3, 2012Massachusetts Institute Of TechnologyConductive lithium storage electrodeUS8168326Jul 30, 2009May 1, 2012A123 Systems, Inc.Battery structures, self-organizing structures and related methodsUS8206468Sep 20, 2010Jun 26, 2012Massachusetts Institute Of TechnologyBattery structures, self-organizing structures and related methodsUS8206469Jun 27, 2011Jun 26, 2012A123 Systems, Inc.Battery structures, self-organizing structures and related methodsUS8241789Sep 27, 2010Aug 14, 2012Massachusetts Institute Of TechnologyBattery structures, self-organizing structures and related methodsUS8277975Jul 19, 2010Oct 2, 2012Massachusetts Intitute Of TechnologyReticulated and controlled porosity battery structuresUS8339040Dec 18, 2008Dec 25, 2012Lumimove, Inc.Flexible electroluminescent devices and systemsUS8435678Apr 18, 2012May 7, 2013A123 Systems, LLCElectrode material with enhanced ionic transport propertiesUS8481208Jun 16, 2010Jul 9, 2013A123 Systems, LLCBipolar articles and related methodsUS8580430Jul 13, 2012Nov 12, 2013Massachusetts Institute Of TechnologyBattery structures, self-organizing structures, and related methodsUS8586238May 15, 2012Nov 19, 2013Massachusetts Institute Of TechnologyBattery structures, self-organizing structures, and related methodsWO2004011901A2 *Jul 22, 2003Feb 5, 2004A123 Systems IncElectrodes and related devices* Cited by examinerClassifications U.S. Classification428/690, 264/21, 313/504, 313/507, 428/691, 428/917International ClassificationH05B33/10, H01L51/50, H05B33/14, C09K11/06Cooperative ClassificationY10S428/917, H05B33/14, H01L27/3239, C09K11/06, H01L51/5012, H05B33/10European ClassificationH01L27/32L2, C09K11/06, H05B33/14, H05B33/10, H01L51/50ELegal EventsDateCodeEventDescriptionJun 28, 2011FPExpired due to failure to pay maintenance feeEffective date: 20110511May 11, 2011LAPSLapse for failure to pay maintenance feesDec 13, 2010REMIMaintenance fee reminder mailedOct 19, 2006FPAYFee paymentYear of fee payment: 8Nov 4, 2002FPAYFee paymentYear of fee payment: 4Sep 23, 1996ASAssignmentOwner name: U.S. PHILIPS CORPORATION, NEW YORKFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SCHOO, HERMANUS F.M.;LIEDENBAUM, COEN T.H.F.;VLEGGAAR, JEROEN J.M.;AND OTHERS;REEL/FRAME:008149/0858;SIGNING DATES FROM 19960823 TO 19960904RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google