WO2017038381A1 - Dispositif d'émission électroluminescent organique - Google Patents

Dispositif d'émission électroluminescent organique Download PDF

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Publication number
WO2017038381A1
WO2017038381A1 PCT/JP2016/073093 JP2016073093W WO2017038381A1 WO 2017038381 A1 WO2017038381 A1 WO 2017038381A1 JP 2016073093 W JP2016073093 W JP 2016073093W WO 2017038381 A1 WO2017038381 A1 WO 2017038381A1
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layer
organic
light emitting
light
emitting device
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PCT/JP2016/073093
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Japanese (ja)
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昭徳 山谷
涼子 宮里
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株式会社カネカ
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details
    • H05B33/06—Electrode terminals
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
    • H05B33/26—Light sources with substantially two-dimensional radiating surfaces characterised by the composition or arrangement of the conductive material used as an electrode
    • H05B33/28—Light sources with substantially two-dimensional radiating surfaces characterised by the composition or arrangement of the conductive material used as an electrode of translucent electrodes
    • 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
    • H10K50/15—Hole transporting layers

Definitions

  • the present invention relates to an organic EL light emitting device.
  • the present invention relates to a highly reliable organic EL light-emitting device in which leakage current is suppressed.
  • An organic EL element is a semiconductor element that converts electrical energy into light energy.
  • organic EL elements aimed at application to display screens of mobile phones and portable displays has been actively conducted. Further, due to improvements in organic materials and the like constituting the organic EL element, the driving voltage of the element is remarkably lowered and the luminous efficiency is increased. For this reason, sales of organic EL light emitting devices in which high-brightness and high-efficiency organic EL elements are put into practical use as lighting devices have also started.
  • Non-Patent Document 1 reports a stacked organic light-emitting device including a charge generation layer as an improvement method.
  • Patent Document 1 proposes a measure for suppressing the leak current and suppressing the occurrence of point defects by setting the thickness of the hole transport layer to a value exceeding 150 nm. That is, according to the manufacturing method described in Patent Document 1, even when dust is mixed in the formation of the organic light emitting layer and a part of the cathode is located on the surface of the hole transport layer, the hole transport layer Can be prevented from breaking down and the occurrence of point defects can be suppressed.
  • the organic EL panel of Patent Document 1 is an organic EL panel for a display in which organic EL elements are arranged in a matrix, and is finely separated from each pixel using a mask on a hole transport layer formed on the entire surface. A light emitting layer is formed.
  • the suppression method of Patent Document 1 focuses on the fact that dust is mixed into the surface of the hole transport layer when this mask is used.
  • the present inventors have intensively studied, and by controlling the total thickness of the hole transport layer and the hole injection layer with respect to the light-transmitting metal oxide electrode layer, the leakage current is suppressed. As a result, the present invention has been accomplished.
  • an anode layer, an organic functional layer, and a cathode layer are stacked on a substrate, and the anode layer, the organic functional layer, and the cathode layer overlap when the substrate is viewed in plan.
  • It has an organic EL element, and the organic functional layer is laminated in the order of a hole transporting layer and a light emitting layer from the anode layer side.
  • the hole transporting layer comprises a hole injection layer and a hole transporting layer.
  • the hole transporting layer is an organic EL light emitting device having an average thickness of 0.5 to 1.5 times the average thickness of the anode layer.
  • the relationship of the film thickness between the anode layer and the light emitting layer satisfies a predetermined relationship. Therefore, it is possible to increase the distance between the anode layer and the cathode layer, and it is possible to reduce the in-plane charge distribution of the organic EL element. Further, it is possible to reduce the possibility of occurrence of a short circuit due to the formation of a conductive path that does not contribute to light emission between the protrusion on the anode layer and the cathode layer, which cause leakage current, or an unexpected conductive path. Thus, according to this aspect, the leak current generation rate can be reduced.
  • the average thickness of the hole transporting layer is not less than 0.5 times and not more than 1.5 times the average thickness of the anode layer, so that sufficient thickness can be secured to reduce the leakage current.
  • a decrease in luminance and an increase in manufacturing cost can be suppressed.
  • the hole transport layer that is cheaper than the hole injection layer is generally formed thicker, an increase in cost due to the thick film of the hole transport layer can be suppressed.
  • the hole injection layer contains an electron-accepting compound, is in contact with the anode layer, and the average thickness of the hole injection layer is 15 nm or less.
  • the injection barrier in hole injection can be reduced, and the drive voltage can be reduced.
  • the hole transporting layer extends along an edge of the anode layer when the substrate is viewed in plan, and a part of the anode layer extends from the hole transporting layer. It is that you are.
  • the anode layer has an anode component constituting the organic EL element and a cathode power supply pad separated from other parts, and when the substrate is viewed in plan, the anode layer has the anode layer.
  • the anode component and the cathode power supply pad of the anode layer are divided by a groove, and a part of the organic functional layer enters the groove.
  • a groove is formed between the anode component of the anode layer and the cathode power supply pad of the anode layer, and a part of the organic functional layer enters the groove. Therefore, in the groove portion, the organic functional layer sinks to the substrate side, and the cathode layer approaches the anode layer side.
  • the average thickness of the hole transporting layer is 0.5 to 1.5 times the average thickness of the anode layer, and the hole transporting layer has a sufficient thickness with respect to the depth of the groove. Therefore, the electrical connection between the anode component and the cathode power supply pad and the electrical connection between the anode component and the cathode layer can be cut off.
  • a more preferable aspect is that the groove is filled with the organic functional layer.
  • the groove is filled with the organic functional layer, it is possible to more reliably prevent the leakage current from being generated by the groove.
  • the average thickness of the anode layer is d 0
  • the refractive index of the x-th layer counted from the anode layer side between the anode layer and the k-th light emitting layer is n kx
  • the thickness is d x
  • the optical path length between the light emitting layer and the light extraction surface of the substrate is optimized, and q takes 0 or a value close to 0, so that the luminance and power efficiency can be improved as compared with the conventional case. .
  • the value of p is a positive integer of 2 or more and the value of q is a decimal that satisfies ⁇ 0.2 ⁇ q ⁇ 0.2.
  • the hole transporting layer has a hole transporting material whose hole mobility is 1.0 ⁇ 10 ⁇ 3 cm 2 / V ⁇ s or more as a main component.
  • Main component refers to a component occupying 50% or more of all components.
  • the amount of voltage increase caused by the hole transporting layer can be suppressed to be small, and an organic EL light emitting device with high power efficiency can be obtained.
  • a preferable aspect is that when the drive voltage at a luminance of 1 cd / m 2 is a threshold voltage (V th ) V, the applied voltage is minus (V th ⁇ 1.0) V or more and plus (V th ⁇ 0.5) V or less. In this range, the absolute value of the current density is less than 1.0 ⁇ 10 ⁇ 4 mA / cm 2 .
  • the organic EL element is film-sealed, the generation of leakage current can be further suppressed.
  • the organic functional layer includes a phosphorescent second light emitting layer
  • the hole transporting layer has an average thickness of 60 nm or more and 120 nm or less, and a power efficiency of 20 lm / W or more during lighting. It is possible to emit white light.
  • the light from the phosphorescent second light emitting layer is amplified by the light interference effect, and the light emission intensity is increased. Therefore, it becomes a high-intensity organic EL light emitting device.
  • the light emitting layer emits blue light when lit
  • the organic functional layer includes a phosphorescent second light emitting layer
  • the average thickness of the hole transporting layer is 80 nm or more. It is 140 nm or less, and can emit white light at a color temperature of 4000 K or more when lit.
  • the light from the light emitting layer emitting blue light is amplified by the light interference effect and the light emission intensity is increased, so that the organic EL light emitting device with a high color temperature is obtained.
  • the light emitting layer emits blue light when lit
  • the organic functional layer includes a phosphorescent second light emitting layer
  • the average thickness of the hole transporting layer is 80 nm or more. It is 120 nm or less, and can emit white light with a power efficiency of 20 lm / W or more at a color temperature of 4000 K or more when lit.
  • both the above-described phosphorescent light-emitting second light-emitting layer and blue light-emitting layer exhibit the light interference effect, and the organic EL light-emitting device has high luminance and high color temperature.
  • An aspect related to the present invention is an organic EL light-emitting device including an organic EL element formed on a light-transmitting insulating substrate, and the organic EL element is in contact with the light-transmitting insulating substrate from the light-transmitting insulating substrate side.
  • a first hole transporting layer in contact with the light-transmitting metal oxide electrode layer from the light-transmitting metal oxide electrode layer side comprising a light-sensitive metal oxide electrode layer, an organic functional layer, and a reflective electrode layer;
  • the average thickness of the first hole transporting layer is not less than 0.5 times and not more than 1.5 times the average thickness of the translucent metal oxide electrode layer.
  • FIG. 1 is a plan view of an organic EL light emitting device according to a first embodiment of the present invention. It is a cross-sectional perspective view of the organic EL light-emitting device of FIG.
  • FIG. 4 is a cross-sectional view showing each cross section of the organic EL light emitting device of FIG. 3, wherein (a) shows an AA cross section and (b) shows a BB cross section. It is explanatory drawing of the organic electroluminescent light emitting device of FIG.
  • FIG. 3 is a perspective view which shows the state which peeled the reflective electrode layer from the organic EL element. It is sectional drawing of the organic EL element of FIG. It is a figure which shows the voltage dependence of the current density and brightness
  • 1 is a cross-sectional configuration diagram of an organic EL element of Example 1.
  • FIG. 1 It is a top view which shows the formation procedure of the organic EL element of Example 1, and (a), (b), (c) in order, and also through the formation region of the lower layer covered with the upper layer so that each layer formation region can be understood.
  • Yes It is a figure which shows the voltage dependence of the current density in the forward bias state before and behind the light emission start voltage of the organic EL element of Example 1, and a reverse bias state.
  • 5 is a graph showing emission spectra of organic EL light emitting devices of Example 1 and Comparative Example 1. It is a graph which shows the emission spectrum of the organic EL light-emitting device of Example 2 and Example 3.
  • the vertical direction is based on FIG. That is, the substrate 1 side is the lower side and the sealing film 11 side is the upper side.
  • the organic EL light emitting device 100 is a lighting device, and is an organic EL panel having a light emitting surface and a back surface as both main surfaces as shown in FIG. That is, the surface of the organic EL light emitting device 100 is a light emitting surface, and the opposite surface is a back surface.
  • the organic EL light emitting device 100 is a light emitting device that emits light from the light emitting region 20 on the light emitting surface side based on light emission of the organic EL element 10 included therein.
  • the organic EL light emitting device 100 preferably emits white light from the light emitting region 20 on the light emitting surface side.
  • the organic EL light emitting device 100 is a member having a planar shape, and is preferably a plate member.
  • the organic EL light emitting device 100 includes an organic EL element 10 formed on a translucent insulating substrate 1 (hereinafter, also simply referred to as “substrate 1”), and is a bottom emission type organic EL light emitting device that extracts light from the substrate 1 side. Device.
  • the organic EL light-emitting device 100 includes a specific organic EL element 10 and suppresses leakage current.
  • the organic EL light emitting device 100 When the driving voltage at the luminance of 1 cd / m 2 shown in FIG. 8B is the threshold voltage (V th ) V, the organic EL light emitting device 100 has a minus (V th ⁇
  • the absolute value of the current density is preferably less than 1.0 ⁇ 10 ⁇ 4 mA / cm 2 at a voltage of 1.0) V or more and plus (V th ⁇ 0.5) V or less. That is, the organic EL light emitting device 100 has an absolute value of current density of 1.0 ⁇ 10 ⁇ 4 mA / cm in a voltage range of ⁇ (V th ⁇ 1.0) V to (V th ⁇ 0.5) V. Preferably it is less than 2 .
  • the light emission start voltage of the organic EL element 10 is the voltage when the luminance is 1 cd / m 2, and the value is the threshold voltage ( V th ). That is, the threshold voltage (V th ) is a voltage when the voltage is increased from 0 V and the luminance becomes 1 cd / m 2 .
  • the organic EL element 10 In the case of a normal organic EL element, the organic EL element 10 itself has a diode characteristic. For this reason, until the threshold voltage (V th ), the characteristic is essentially close to an insulator.
  • V th threshold voltage
  • the characteristic is essentially close to an insulator.
  • the film itself is more likely to deteriorate compared to other portions.
  • the deterioration of the organic EL element 10 is promoted, it becomes difficult for current to flow through the portion, and a region that does not emit light is generated and becomes a dark spot. Therefore, in order to provide an organic EL light emitting device that does not substantially generate a dark spot, it is necessary to use the organic EL element 10 in which leakage current is suppressed.
  • One of the characteristics is that generation of a leakage current generated in the light-transmitting metal oxide electrode layer 2 is suppressed by optimizing the ratio of the above.
  • the organic EL light emitting device 100 has a light emitting region 20 corresponding to the organic EL element 10 on its light emitting surface.
  • the organic EL light emitting device 100 preferably includes a sealing region 70 including a sealing film 11 that covers the entire surface of the light emitting region 20 on the back surface when viewed in plan. By doing so, it is possible to prevent moisture from entering the organic EL element 10 and to suppress the generation of dark spots.
  • the sealing film 11 has at least an inorganic sealing layer having a thickness of 1 ⁇ m or more and 10 ⁇ m or less in contact with the organic EL element 10 and an adhesive layer in contact with the inorganic sealing layer.
  • the sealing film 11 includes an inorganic sealing layer that covers the organic EL element 10 and an adhesive layer that covers the outer side of the inorganic sealing layer in the thickness direction. More preferably, the organic EL light emitting device 100 includes a soaking film or an exterior film on the sealing film 11.
  • the light emitted from the light emitting region 20 when the organic EL light emitting device 100 is turned on has a spectrum with one emission peak in the range of 500 nm to 580 nm and one emission in the range of 590 nm to 650 nm.
  • White light having a peak is preferable. More preferably, the white light further has an emission peak in the range of 450 nm to 480 nm.
  • the organic EL light emitting device 100 of the present embodiment includes one emission peak in each of the ranges of light irradiated from the light emitting region 20 in the range of 450 nm to 480 nm, 500 nm to 580 nm, and 590 nm to 650 nm. ing.
  • the TCO layer 2 constituting a part of the organic EL element 10 is an organic layer continuous from the organic functional layer 3 constituting a part of the organic EL element 10 when the substrate 1 is viewed in cross section as shown in FIG.
  • the first hole transporting layer 4 of the functional layer 3 covers the side surface.
  • the value of p is a positive integer of 1 or more, and The value of q is ⁇ 0.2 ⁇ q ⁇ 0.2, More preferably, the decimal number is ⁇ 0.1 ⁇ q ⁇ 0.1.
  • the maximum wavelength of light emitted from the k-th light-emitting layer and L k counted from the light transmission metal oxide electrode layer 2 a refractive index at a maximum wavelength L k of the transparent metal oxide electrode layer 2 N k0 , film thickness d 0 , between the translucent metal oxide electrode layer 2 and the kth light emitting layer, and the refractive index of the xth layer counted from the translucent metal oxide electrode layer 2 side Is n kx and the average film thickness is d x .
  • the average thickness of the TCO layer 2 is preferably 50 nm or more, and more preferably 70 nm or more.
  • the average thickness of the TCO layer 2 is preferably 200 nm or less, and more preferably 160 nm or less.
  • a conductive polymer material such as PEDOT: PSS can be given as a representative example of the hole injection layer material.
  • this polymer material is laminated by a coating method, its lifetime is inferior to that of an organic EL element produced by a vapor deposition method. Therefore, in order to be a highly reliable organic EL element, it is preferable that the hole injection layer 41 is also laminated with a low molecule by a vapor deposition method.
  • the average thickness of the first hole transporting layer 4 is 80 nm or more and 120 nm or less from the viewpoint that the luminance is improved including the phosphorescent second light emitting layer 52 and the organic EL element 10 has a high color temperature. More preferably.
  • the voltage increase width V (V) of the drive voltage caused by the resistance of these layers can be estimated using the space charge limited current (SCLC) formula shown by the following formula 2.
  • J is a current density flowing through the organic EL element 10, and this value is assumed to be 5 mA / cm 2 as a general rated current density, and the mobility ⁇ of the hole transport material is 1.0 ⁇ 10 ⁇ 3.
  • the thickness L of the hole transport layer 15 is 100 nm.
  • the increase amount V of the drive voltage is about 0.2V. It can be said that this voltage increase width is sufficiently smaller than the driving voltage (for example, 6.9 V in Example 1 described later).
  • the second light emitting layer 52 is a phosphorescent light emitting layer, and is preferably a light emitting layer that emits red and green light.
  • the second light-emitting layer 52 may have a structure in which a red sub-light-emitting layer that emits light of each color and a green sub-light-emitting layer are stacked, but a single light-emitting layer including a red phosphorescent material, a green phosphorescent material, and a phosphorescent light-emitting layer host material It is preferable that When the second light emitting layer 52 is a single light emitting layer, it is more preferable that the second light emitting layer 52 uniformly includes a red phosphorescent material, a green phosphorescent material, and a phosphorescent layer host material. That is, the second light emitting layer 52 is preferably a red-green light emitting layer containing a red phosphorescent material, a green phosphorescent material, and a
  • the maximum emission peak wavelength of the red phosphorescent material is preferably separated from the maximum emission peak wavelength of the green phosphorescent material by 50 nm or more. By doing so, it becomes possible to irradiate light with high color rendering properties.
  • it can emit light with high color-rendering index R a and the special color rendering index R 9.
  • the average color rendering index R a and the special color rendering index R 9 pursuant to JIS Z 8726 are both enables emission of 90 or more.
  • the reflective electrode layer 6 is a layer having conductivity and light reflectivity.
  • the reflective electrode layer 6 is a back electrode layer formed on the back surface side, and is a layer constituting the cathode layer of the organic EL element 10.
  • the reflective electrode layer 6 can be formed using a material capable of forming a thin film, for example, a metal material. From the viewpoint of making the organic EL light emitting device 100 with high brightness, the reflective electrode layer 6 is preferably a white glossy metal layer among various metal materials, among which silver (Ag) and aluminum (Al) are preferable. More preferred.
  • the organic functional layer 3 of the present embodiment includes a first light emitting unit 30 including the first light emitting layer 5, a second light emitting unit 31 including the second light emitting layer 52, and the first A connection layer 32 for connecting the light emitting unit 30 and the second light emitting unit 31 is provided.
  • the light emitting units 30 and 31 are composed of a plurality of organic layers mainly made of an organic compound.
  • an organic compound known materials such as low molecular dye materials and conjugated polymer materials generally used in organic EL elements can be used.
  • each light emitting unit 30 and 31 has light emitting layers 5 and 52 that actually emit light in the layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, etc.
  • a plurality of layers can be included, and these layers other than the light emitting layer mainly have a function of promoting light emission in the light emitting layer.
  • These layers are formed by a known method such as a vacuum deposition method, a sputtering method, a CVD method, a dipping method, a roll coating method (printing method), a spin coating method, a bar coating method, a spray method, a die coating method, or a flow coating method.
  • a vacuum deposition method such as a vacuum deposition method, a sputtering method, a CVD method, a dipping method, a roll coating method (printing method), a spin coating method, a bar coating method, a spray method, a die coating method, or a flow coating method.
  • I can make a film.
  • These layers are preferably formed by vacuum deposition from the viewpoint of the high-performance organic EL element 10.
  • the color rendering properties, spectrum, and color temperature are those for the organic EL light emitting device 100 including the light extraction layer 7.
  • the anode power supply extension region 61 is a portion that supplies power to the anode component 60 that is the anode of the organic EL element 10, and is continuous with the anode component 60 when viewed in plan. This is a portion extending outward from the anode component 60.
  • Each anode power supply extension region 61 belongs to the power supply region 21 and is arranged at a predetermined interval in the circumferential direction.
  • the pad connection portion 68 of the reflective electrode layer 6 is laminated on the electrode protection portion 66 of the organic functional layer 3, and its end portion is connected to the cathode power supply pad 62. Therefore, the anode power supply extension region 61 is electrically connected to the element component of the TCO layer 2 of the organic EL element 10, and the cathode power supply pad 62 is connected to the reflective electrode layer 6 of the organic EL element 10.
  • the cathode component 67 is electrically connected.
  • the light emitting layers 5 and 52 are layers in which a host material having a hole transporting property or an electron transporting property is doped with a light emitting material.
  • the light emitting layers 5 and 52 are layers in which luminescent excitons are generated by combining holes flowing from the hole transport layers 15 and 51 and electrons flowing from the electron transport layers 17 and 53 by applying an electric field.
  • the thickness of the light emitting layers 5 and 52 is preferably 1 nm or more and 40 nm or less.
  • triazole compound examples include 3-phenyl-4- (1'-naphthyl) -5-phenyl-1,2,4-triazole (TAZ).
  • Electrode-accepting dopant As the electron-accepting dopant, a tetracyanoquinodimethane compound, molybdenum oxide (MoO 3 ), tungsten oxide (WO 3 ), vanadium oxide (V 2 O 5 ), or the like can be employed.
  • MoO 3 molybdenum oxide
  • WO 3 tungsten oxide
  • V 2 O 5 vanadium oxide
  • Tetracyanoquinodimethane compounds include tetracyanoquinodimethane (TCNQ). Examples include 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ).
  • dihydroimidazole compound examples include bis- [1,3 diethyl-2-methyl-1,2-dihydrobenzimidazolyl] tetrathiafulvalene (TTF), tetrathianaphthacene (TTT), and the like.
  • the organic EL light emitting device 100 of the present embodiment since the optical path length between the light emitting layers 5 and 52 and the translucent insulating substrate 1 can be easily optimized, high brightness and high color temperature are easily obtained. Moreover, the voltage rise resulting from the 1st hole transportable layer 4 can be suppressed, and it can also be set as high power efficiency.
  • the organic functional layer 3 has a structure in which the two light emitting units 30 and 31 are connected by the connection layer 32, but the present invention is not limited to this.
  • the organic functional layer 3 may have a structure including one light emitting unit 30, or may have a structure in which three or more light emitting units are stacked directly or via a connection layer 32.
  • Example 1 Light-emitting element 1a
  • Example 1 an organic EL light emitting device 100 as shown in FIGS. 1 and 2 was produced.
  • FIGS. 10 (a), 10 (b), and FIG. The organic EL element 10 having the light emitting region 20 of 80.4 mm ⁇ 80.4 mm was formed as the organic EL element 10 in the order shown in the order of 10 (c). Thereafter, when viewed in plan, a sealing region 70 is formed by the sealing film 11 so as to include the light emitting region 20, and an optical film (OCF film) as the light extraction layer 7 is attached to the light emitting side of the substrate 1. did. Thus, the organic EL light emitting device 100 was produced.
  • FIG. 9 shows a cross-sectional configuration diagram of the organic EL element 10 of the first embodiment.
  • an ITO film on the glass substrate 1 was patterned by a wet etching method to prepare an organic EL element forming substrate having the ITO layer 2 shown in FIG.
  • This substrate for forming an organic EL element is composed of the same ITO film around the central ITO layer 2 to be the organic EL element 10, eight cathode power supply pads 62 at the four corners, and anodes at the four sides.
  • the power supply extension region 61 is provided with four regions. Normally, after this, the surface of the TCO layer 2 is polished to perform a polishing process for reducing the density of leak defects originating from the surface. However, in Example 1, this polishing process was not performed. . That is, it is in a state where a leak current is intentionally easily generated.
  • an organic functional layer 3 (FIG. 10B) and an aluminum (Al) layer 6 (FIG. 10) are formed on the organic EL light-emitting element substrate so as to have a cross-sectional configuration diagram shown in FIG.
  • Each of (c)) was laminated by a vacuum deposition method using a predetermined mask to form a light emitting element 1a as the organic EL element 10 of Example 1.
  • FIG. 10B ′ the side surface of the TCO layer 2 included in the organic EL element 10 and covered with the organic functional layer 3 is indicated by a bold line.
  • a hole injection layer (HIL1) which is a first hole injection layer 41 in contact therewith, and a hole transport layer Two layers (HTL1) were formed, and the first light-emitting layer 5 (EML1) was formed in contact with the hole transport layer (HTL1).
  • the organic functional layer 3 including these was further formed to include EML2 as the phosphorescent second light emitting layer 52.
  • each layer at that time was formed so as to have the value shown in the light-emitting element 1a in Table 1.
  • the degree of vacuum was set to a high vacuum of 2 ⁇ 10 ⁇ 5 Pa or more, and vacuum deposition was performed at a predetermined speed. Layers made of two or more materials such as a light emitting layer were co-deposited at a predetermined mixing ratio.
  • the deposition rate of the aluminum (Al) layer 6 was controlled to be 0.5 to 2.0 nm / sec.
  • the average thickness of the ITO layer 2 was 120 nm, and the average thickness of the first hole transporting layer 4 was 74 nm (HIL1 (14 nm) + HTL1 (60 nm)). That is, the average thickness of the first hole transporting layer 4 was 0.62 times the average thickness of the ITO layer 2.
  • the average thickness of the organic functional layer 3 is 268 nm, which is 2.23 times the average thickness of the ITO layer 2. That is, the average thickness of the organic functional layer 3 is at least twice the average thickness of the ITO layer 2.
  • a blue fluorescent light emitting layer having a light emission maximum wavelength between 450 and 480 nm is used as the first light emitting layer 5 (EML1), and a light emission maximum wavelength is 500 as the second light emitting layer 52 (EML2).
  • EML1 first light emitting layer 5
  • EML2 second light emitting layer 52
  • a phosphorescent emitting layer between ⁇ 650 nm was used.
  • the hole transporting layers 15 and 51 have a hole transporting material having a hole mobility of 2.3 ⁇ 10 ⁇ 3 cm 2 / V ⁇ s.
  • the hole injection layers 41 and 50 were formed by co-evaporation of the hole transport layer material and an organic material serving as an electron-accepting dopant.
  • a silicon nitride film having an average thickness of about 1.6 ⁇ m was formed on the organic EL element 10 by a CVD method using a predetermined mask.
  • polysilazane was applied by a spray method and baked to form a silica conversion layer having an average thickness of about 0.6 ⁇ m.
  • region 70 comprised by the sealing film 11 was formed by affixing the protective film which consists of PET with an adhesive material on this sealed organic EL element 10.
  • the OCF film 7 was pasted on the surface of the glass substrate 1 opposite to the surface on which the elements were formed, to produce the organic EL light emitting device 100 of Example 1.
  • FIG. 11 shows the measurement results of the voltage dependency of current density and luminance under the forward bias state and the reverse bias state before and after the light emission start voltage.
  • Table 3 shows the results of a leak evaluation test described later.
  • FIG. 12 shows an emission spectrum in the central portion of the organic EL light emitting device 100.
  • the threshold voltage (V th ) which is the voltage when the luminance becomes 1 cd / m 2 , is about 4.8V.
  • a value 0.5 V lower than the threshold voltage is set as the maximum value of the applied voltage at the time of determining whether the leakage current is acceptable in the forward direction.
  • the criterion for determining the leakage current value in the forward bias state was set to less than 1.0 ⁇ 10 ⁇ 4 mA / cm 2 from 0 V to (threshold voltage ⁇ 0.5) V.
  • the absolute value of the leakage current is 1.0 ⁇ 10 ⁇ 4 mA / cm 2 in the reverse bias state from 0 V to (threshold voltage ⁇ 1.0) V absolute value. Less than. That is, if the leakage current value in the forward bias state is less than 1.0 ⁇ 10 ⁇ 4 mA / cm 2 in the range of 0 V to (threshold voltage ⁇ 0.5) V, the leakage current is obtained in the reverse bias state. If the value was less than 1.0 ⁇ 10 ⁇ 4 mA / cm 2 in the range of 0 V to minus (threshold voltage ⁇ 1.0) V, the test was accepted.
  • the absolute value of the leakage current is smaller than the reference value in this applied voltage range.
  • the current value increased exponentially with respect to the applied voltage from 0 V to the emission start voltage.
  • the logarithm of the current value was proportional to the voltage, and when the light emission start voltage was exceeded, the charge injection increased rapidly, so that the current value rose vertically and light emission was confirmed.
  • the current value up to the light emission start voltage is larger than that in a normal organic EL element.
  • the leak defects that will be a problem in the future in the forward bias state which is the state when the organic EL light emitting device 100 is actually turned on, it cannot be found as a leak defect in the initial leak inspection, and is not detected There is a leak defect. That is, among the leak defects that will be a problem in the future, there are non-exposed leak defects that cannot be detected as leak defects in the initial leak inspection in the forward bias state, and are not detected.
  • Table 3 shows the measurement results of 100 light emitting elements 1a of Example 1 as the number distribution in each range of leakage current. That is, Table 3 shows the result of measurement for 100 light emitting elements 1a of Example 1 as a number distribution according to the leakage current density classification.
  • Comparative Example 1 Light-Emitting Element 1b
  • An organic EL light emitting device of Comparative Example 1 was prepared and evaluated in the same manner except that the film thickness of the hole transport layer 15 (HTL1) having a thickness of 60 nm in Example 1 was 24 nm. That is, the specific thickness of each layer was set to the value shown in the light-emitting element 1b in Table 1.
  • HTL1 hole transport layer 15
  • the average thickness of the ITO layer 2 was 120 nm, and the average thickness of the first hole transporting layer 4 was 38 nm (HIL1 (14 nm) + HTL1 (24 nm)). That is, the average thickness of the first hole transporting layer 4 was 0.32 times the average thickness of the ITO layer 2.
  • the average thickness of the organic functional layer 3 is 232 nm, which is 1.93 times the average thickness of the ITO layer 2. That is, the average thickness of the organic functional layer 3 is less than twice the average thickness of the ITO layer 2.
  • Example 1 For the organic EL light emitting device of Comparative Example 1, measurement of current-voltage-luminance characteristics, leak evaluation test, and spectrum measurement were performed in the same manner as in Example 1.
  • the organic EL light emitting device of Comparative Example 1 had a light emission power efficiency of 38.51 lm / W when a constant current of 220 mA was applied.
  • the result of Comparative Example 1 is shown in Table 2, Table 3, and FIG.
  • the luminance of the organic EL light emitting device 100 of Example 1 was improved by about 150 cd / m 2 as compared with the organic EL light emitting device of Comparative Example 1.
  • the voltage was almost the same as that of the element 1b of Comparative Example 1 although the hole transport layer (HTL1) was thickened compared to Comparative Example 1.
  • Example 1 As shown in Table 3, the element 1a of Example 1 passed 62% of the total, whereas the element 1b of Comparative Example 1 passed only 6%. . From this, in Example 1, it is thought that the pass rate was greatly improved due to the effect of increasing the thickness of the first hole transporting layer 4.
  • the organic EL light-emitting device 100 of Example 1 has higher emission intensity in almost all wavelength regions than the organic EL light-emitting device of Comparative Example 1, and this is particularly noticeable at 500 nm to 650 nm. It was. This leads to the aforementioned luminance result.
  • the device 100 of Example 1 satisfies the above-described emission intensity enhancement condition, and the device of Comparative Example 1 does not satisfy the emission intensity enhancement condition. That is, with respect to the optical path length from the interface between the glass substrate 1 and the ITO layer 2 to the HTL2 / EML2 interface that is the interface on the ITO layer 2 side of the phosphorescent second light emitting layer 52, ⁇ n kx d x in the following formula 1 When the value is obtained, it is 554 nm for the element 1 a of the device 100 of the first embodiment and 491 nm for the element 1 b of the device of the first comparative example.
  • the value closest to the value of ⁇ n kx d x of the element 1a is when p is 2 and q is ⁇ 0.02, which is 554.4. Is the time.
  • the value closest to the value of ⁇ n kx d x of the element 1b is when p is 2 and q is ⁇ 0.25, which is 490 nm. Is the time.
  • the element 1a since the value of q of the element 1a is smaller than that of the element 1b and it matches the emission intensity enhancement condition, it is considered that the element 1a has a high luminance that does not have strong phosphorescence intensity compared to the element 1b.
  • the values shown in Table 4 were used as the refractive index values of the ITO layer 2 and the organic functional layer 3.
  • Example 2 Light-emitting element 2a
  • the organic EL light-emitting device 100 of Example 2 was produced and evaluated in the same manner except that the thickness of each layer in Example 1 was set to the value shown in the light-emitting element 2a of Table 1.
  • the average thickness of the ITO layer 2 was 120 nm, and the average thickness of the first hole transporting layer 4 was 114 nm (HIL1 (14 nm) + HTL1 (100 nm)). That is, the average thickness of the first hole transporting layer 4 was 0.95 times the average thickness of the ITO layer 2.
  • the average thickness of the organic functional layer 3 is 314 nm, which is 2.62 times the average thickness of the ITO layer 2.
  • the current-voltage-luminance characteristics were measured in the same manner as in Example 1 except that the current value at the time of measurement was 4.4 mA / cm 2 (285 mA), and Spectrum measurement was performed.
  • the organic EL light emitting device 100 of Example 2 had a light emission power efficiency of 25.11 lm / W when a constant current of 285 mA was applied.
  • Example 3 Light-emitting element 3a
  • the organic EL light emitting device 100 of Example 3 was produced and evaluated in the same manner except that the film thickness of HTL1 of 100 nm in Example 2 was changed to 60 nm. That is, the specific thickness of each layer was set to the value shown for the light emitting element 3a in Table 1.
  • the average thickness of the ITO layer 2 was 120 nm, and the average thickness of the first hole transporting layer 4 was 74 nm (HIL1 (14 nm) + HTL1 (60 nm)). That is, the average thickness of the first hole transporting layer 4 was 0.62 times the average thickness of the ITO layer 2. Moreover, the average thickness of the organic functional layer 3 is 274 nm, which is 2.28 times the average thickness of the ITO layer 2.
  • the organic EL light emitting device 100 of Example 3 was measured for current-voltage-luminance characteristics and spectrum measurement in the same manner as Example 2.
  • the light emission power efficiency of the organic EL light emitting device 100 of Example 3 when the 285 mA constant current was applied was 25.06 lm / W.
  • Example 2 The results of Example 2 and Example 3 are shown in Table 5 and FIG.
  • the intensity of the blue light emission peak was improved by about 8% compared to the organic EL light emitting device 100 of Example 3. Accordingly, as shown in Table 5, in the organic EL light emitting device 100 of Example 2, the color temperature was improved by about 200K compared to the organic EL light emitting device 100 of Example 3.
  • the element 2a of Example 2 has the same voltage as that of the element 3a of Example 3 although the hole transport layer (HTL1) is thicker than the element 3a of Example 3. It was almost the same.
  • the device 100 of Example 2 satisfies the above-described emission intensity enhancement condition
  • the device 100 of Example 3 satisfies the above-described emission intensity enhancement condition. It is thought that there is not. That is, the optical path length from the interface between the glass substrate 1 and the ITO layer 2 to the HTL1 / EML1 interface that is the interface between the first hole transporting layer 4 and the first light emitting layer 5 is the same as described above.
  • the value of ⁇ n kx d x in Equation 1 is obtained using the numerical values shown in FIG.
  • the peak wavelength of blue is 470 nm
  • the value closest to the value of ⁇ n kx d x of the element 2a is when p is 2 and q is ⁇ 0.08, which is 451.2. It is.
  • the blue peak wavelength is 470 nm
  • the value closest to the value of ⁇ n kx d x of the element 3a is when p is 2 and q is ⁇ 0.39, which is 378.35. Is the time.
  • the value of q of the element 2a is smaller than that of the element 3a and the emission intensity enhancement condition is met. Therefore, the element 2a has a higher intensity of blue fluorescent light emission and a higher color temperature than the element 3a. Conceivable.

Abstract

L'invention concerne un dispositif d'émission électroluminescent organique qui peut supprimer l'apparition de courant de fuite en raison du recouvrement par une couche fonctionnelle organique des surfaces latérales d'une couche d'électrode positive et de la proximité de la couche d'électrode positive et d'une couche d'électrode négative. La présente invention concerne un élément électroluminescent organique dans lequel la couche d'électrode positive, la couche fonctionnelle organique, et la couche d'électrode négative sont stratifiées sur un substrat, et lorsque le substrat est vu dans une vue en plan, la couche d'électrode positive, la couche fonctionnelle organique, et la couche d'électrode négative sont superposées. La couche fonctionnelle organique est formée par stratification, à partir du côté couche d'électrode positive, d'une couche à propriété de transport de trous et d'une couche d'émission, dans cet ordre. La couche à propriété de transport de trous comprend une couche d'injection de trous et une couche de transport de trous et est en contact avec la couche d'électrode positive ainsi qu'avec la couche d'émission. Lorsque l'élément électroluminescent organique est vu en coupe transversale, au moins une partie des surfaces latérales de la couche d'électrode positive est recouverte par la couche fonctionnelle organique, et l'épaisseur moyenne de la couche à propriété de transport de trous est de 0,5 à 1,5 fois l'épaisseur moyenne de la couche d'électrode positive.
PCT/JP2016/073093 2015-09-03 2016-08-05 Dispositif d'émission électroluminescent organique WO2017038381A1 (fr)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006085615A1 (fr) * 2005-02-10 2006-08-17 Tohoku Pioneer Corporation Dispositif luminescent et panneau luminescent
WO2012096232A1 (fr) * 2011-01-13 2012-07-19 株式会社カネカ Élément électroluminescent organique et son procédé de fabrication
WO2013031345A1 (fr) * 2011-09-02 2013-03-07 コニカミノルタホールディングス株式会社 Élément organique à électroluminescence
JP2013070086A (ja) * 2012-12-14 2013-04-18 Panasonic Corp 有機電界発光素子
WO2013176069A1 (fr) * 2012-05-23 2013-11-28 コニカミノルタ株式会社 Élément électroluminescente organique et procédé pour sa fabrication
JP2014044894A (ja) * 2012-08-28 2014-03-13 Konica Minolta Inc 有機エレクトロルミネッセンス素子
WO2014057678A1 (fr) * 2012-10-11 2014-04-17 パナソニック株式会社 Élément électroluminescent organique et appareil d'éclairage
JP2014232861A (ja) * 2013-04-30 2014-12-11 キヤノン株式会社 有機発光素子

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006085615A1 (fr) * 2005-02-10 2006-08-17 Tohoku Pioneer Corporation Dispositif luminescent et panneau luminescent
WO2012096232A1 (fr) * 2011-01-13 2012-07-19 株式会社カネカ Élément électroluminescent organique et son procédé de fabrication
WO2013031345A1 (fr) * 2011-09-02 2013-03-07 コニカミノルタホールディングス株式会社 Élément organique à électroluminescence
WO2013176069A1 (fr) * 2012-05-23 2013-11-28 コニカミノルタ株式会社 Élément électroluminescente organique et procédé pour sa fabrication
JP2014044894A (ja) * 2012-08-28 2014-03-13 Konica Minolta Inc 有機エレクトロルミネッセンス素子
WO2014057678A1 (fr) * 2012-10-11 2014-04-17 パナソニック株式会社 Élément électroluminescent organique et appareil d'éclairage
JP2013070086A (ja) * 2012-12-14 2013-04-18 Panasonic Corp 有機電界発光素子
JP2014232861A (ja) * 2013-04-30 2014-12-11 キヤノン株式会社 有機発光素子

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