JP2011003359A - Organic el device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL device capable of suppressing a short circuit between a pixel electrode and a counter electrode.SOLUTION: This organic EL device includes an insulating substrate, a pixel electrode disposed above the insulating substrate, a barrier plate disposed around the pixel electrode, an interlayer insulating film extending from the barrier plate to the peripheral part of the pixel electrode and exposing the center part of the pixel electrode, and organic layer disposed on the interlayer insulating film and the center part of the pixel electrode, and a counter electrode disposed on the organic layer.

Description

  The present invention relates to an organic electroluminescence (EL) device.

  In recent years, active development of display devices using organic electroluminescence (EL) elements that are self-luminous, have high-speed response, wide viewing angle, high contrast, and can be made thinner and lighter. It has been broken.

  For example, according to Patent Document 1, as a technique for suppressing a short circuit between a pixel electrode and a counter electrode, a pixel separation partition wall formed between pixels and formed above an interlayer insulating film having a depression is provided. An organic EL display device is disclosed in which an outer edge portion of a pixel separation partition wall is disposed in a region of an inner surface of a recess portion.

JP 2007-287346 A

  An object of the present invention is to provide an organic EL device capable of suppressing a short circuit between a pixel electrode and a counter electrode.

According to one aspect of the invention,
An insulating substrate; a pixel electrode disposed above the insulating substrate; a partition disposed around the pixel electrode; and a central portion of the pixel electrode extending from the partition to a peripheral edge of the pixel electrode An interlayer insulating film exposing a portion; an organic layer disposed on the interlayer insulating film; and a central portion of the pixel electrode; and a counter electrode disposed on the organic layer. An organic EL device is provided.

According to one embodiment of the present invention,
An insulating substrate; a pixel electrode disposed above the insulating substrate; a partition disposed around the pixel electrode; an organic layer disposed on the pixel electrode; and an organic layer disposed on the organic layer. A counter electrode; and an interlayer insulating film disposed between the partition and the organic layer, in contact with the pixel electrode, and covering a gap formed between the partition and the pixel electrode. An organic EL device characterized by the above is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the organic electroluminescent apparatus which can suppress the short circuit with a pixel electrode and a counter electrode can be provided.

FIG. 1 is a plan view schematically showing a configuration of an organic EL device according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of an array substrate including an organic EL element of the organic EL display device according to this embodiment. FIG. 3 is a cross-sectional view schematically showing a structure around a partition wall in the array substrate shown in FIG. FIG. 4 is a cross-sectional view schematically showing a state where the partition wall is peeled off from the pixel electrode. FIG. 5 is a cross-sectional view schematically showing another structure around the partition wall in the array substrate shown in FIG.

  Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In each figure, the same reference numerals are given to components that exhibit the same or similar functions, and duplicate descriptions are omitted.

  FIG. 1 is a plan view schematically showing a configuration of an organic EL display device adopting an active matrix driving method as an example of an organic EL device.

  That is, the organic EL device includes the display panel 1. The display panel 1 includes an array substrate 100 and a sealing substrate 200. The array substrate 100 includes a plurality of organic EL elements OLED arranged in a matrix in an approximately rectangular active area 102 for displaying an image. The sealing substrate 200 faces the organic EL element OLED of the array substrate 100 in the active area 102. The sealing substrate 200 is an insulating substrate having optical transparency such as glass or plastic.

  The array substrate 100 and the sealing substrate 200 are bonded together by a seal member 300 formed in a frame shape surrounding the active area 102. The seal member 300 is made of, for example, an organic material such as an ultraviolet curable resin or frit glass. When the seal member 300 is formed of an organic material, the resin layer may be filled inside the array member 100 and the sealing substrate 200 surrounded by the seal member 300. In this case, the resin layer to be filled can be formed of, for example, an organic material having optical transparency such as an ultraviolet curable resin.

  In addition, the array substrate 100 includes an extending portion 110 that extends outward from the end portion 200E of the sealing substrate 200 in the peripheral area 104 outside the active area 102. The extending part 110 is provided with a driving part 130. The driving unit 130 includes a driving IC chip and a flexible printed circuit (hereinafter referred to as FPC) that supply signals necessary for driving the organic EL element OLED such as a power source and various control signals to the organic EL element OLED. A signal supply source such as) can be connected.

  FIG. 2 is a cross-sectional view of the array substrate 100 including the organic EL element OLED of the organic EL device.

  The array substrate 100 includes an insulating substrate 101 such as glass, a switching element SW formed above the insulating substrate 101, an organic EL element OLED, and the like. An undercoat layer 111 is disposed on the insulating substrate 101. The undercoat layer 111 is made of an inorganic material such as silicon oxide or silicon nitride, for example. Such an undercoat layer 111 extends over substantially the entire active area 102.

  On the undercoat layer 111, the semiconductor layer SC of the switching element SW is disposed. The semiconductor layer SC is made of, for example, polysilicon. In the semiconductor layer SC, a source region SCS and a drain region SCD are formed with a channel region SCC interposed therebetween.

  The semiconductor layer SC is covered with a gate insulating film 112. The gate insulating film 112 is also disposed on the undercoat layer 111. The gate insulating film 112 is formed of an inorganic material such as silicon oxide or silicon nitride, for example. Such a gate insulating film 112 extends over substantially the entire active area 102.

  On the gate insulating film 112, the gate electrode G of the switching element SW is disposed immediately above the channel region SCC. In this example, the switching element SW is a top gate type p-channel thin film transistor. The gate electrode G is covered with a passivation film 113. The passivation film 113 is also disposed on the gate insulating film 112. The passivation film 113 is made of, for example, an inorganic material such as silicon oxide or silicon nitride. Such a passivation film 113 extends over substantially the entire active area 102.

  On the passivation film 113, the source electrode S and the drain electrode D of the switching element SW are disposed. The source electrode S is in contact with the source region SCS of the semiconductor layer SC. The drain electrode D is in contact with the drain region SCD of the semiconductor layer SC. The gate electrode G, the source electrode S, and the drain electrode D of the switching element SW are formed using a conductive material such as molybdenum (Mo), tungsten (W), aluminum (Al), or titanium (Ti).

  The source electrode S and the drain electrode D are covered with an insulating film 114. The insulating film 114 is also disposed on the passivation film 113. Such an insulating film 114 is made of, for example, an organic material such as an ultraviolet curable resin or a thermosetting resin, or various inorganic materials such as silicon nitride (SiN). Further, such an insulating film 114 extends over the entire active area 102.

  The pixel electrode PE constituting the organic EL element OLED is disposed on the insulating film 114. The pixel electrode PE is connected to the drain electrode D of the switching element SW. The pixel electrode PE corresponds to an anode in this example.

  The pixel electrode PE has a two-layer structure in which a reflective electrode PER and a transmissive electrode PET are stacked. That is, the reflective electrode PER is disposed on the insulating film 114. The transmissive electrode PET is disposed on the reflective electrode PER. The reflective electrode PER is formed of a conductive material having light reflectivity such as silver (Ag) or aluminum (Al). The transmissive electrode PET is formed of a conductive material having optical transparency such as indium tin oxide (ITO) and indium zinc oxide (IZO). Note that the pixel electrode PE is not limited to the above-described two-layer structure, and may be a laminated structure of three or more layers, a reflective electrode PER single layer, or a transmissive electrode PET single layer. good. When the microcavity structure is employed, the pixel electrode PE includes a reflective electrode PER.

  A partition wall PI is disposed on the insulating film 114. The partition wall PI is disposed around the pixel electrode PE. Further, the partition wall PI overlaps with a part of the pixel electrode PE. Such a partition wall PI is formed of, for example, an organic material such as an ultraviolet curable resin or a thermosetting resin, or an insulating material such as various inorganic materials. The partition wall PI has a side surface PIS and an upper surface PIT.

  The organic layer ORG constituting the organic EL element OLED is arranged on the pixel electrode PE exposed from the partition wall PI. The organic layer ORG includes at least a light emitting layer, and may further include a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and the like. The material of the organic layer ORG may include a fluorescent material or a phosphorescent material.

  An interlayer insulating film 120 is disposed between the organic layer ORG and the partition wall PI. The interlayer insulating film 120 is in contact with the pixel electrode PE. Such an interlayer insulating film 120 is formed of an inorganic insulating material such as silicon oxide or an organic material such as TPT (abbreviation of N, N′-Bis (4-diphenylamino-4-biphenyl) -N, N′-diphenylbenzidine). It is made of a system insulating material. The structure of the interlayer insulating film 120 will be described in detail later.

  The counter electrode CE constituting the organic EL element OLED is arranged on the organic layer ORG. In this example, the counter electrode CE corresponds to a cathode. Such a counter electrode CE is composed of, for example, a transmissive layer formed of a conductive material such as ITO or IZO, or a semi-transmissive layer formed of magnesium / silver or the like. When the microcavity structure is employed, the counter electrode CE includes a semi-transmissive layer formed of magnesium, silver, or the like. Such a counter electrode CE extends over the entire active area 102.

  FIG. 3 is a cross-sectional view schematically showing the structure around the partition wall PI. In FIG. 3, only the main parts necessary for explanation are shown.

  The partition wall PI is disposed between each pixel electrode PE of the adjacent first organic EL element OLED1 and second organic EL element OLED2. Each pixel electrode PE is disposed on the insulating film 114. The partition wall PI is disposed on the insulating film 114 and overlaps the peripheral edge portion PEP of each pixel electrode PE. The partition wall PI has a substantially trapezoidal cross section, and includes a side surface PIS that faces the first organic EL element OLED1 and the second organic EL element OLED2, and an upper surface PIT that connects the side surfaces PIS. ing. The central portion PEC of each pixel electrode PE is exposed from the partition wall PI.

  The interlayer insulating film 120 covers each side surface PIS and the upper surface PIT of the partition wall PI. The interlayer insulating film 120 extends from the partition wall PI to the peripheral edge PEP of the pixel electrode PE. That is, the interlayer insulating film 120 is in close contact with the peripheral edge portion PEP of the pixel electrode PE and covers the boundary B between the partition wall PI and the pixel electrode PE. Such an interlayer insulating film 120 exposes the central portion PEC of the pixel electrode PE.

  In the present embodiment, the peripheral edge portion PEP of the pixel electrode PE is a portion in contact with the partition wall PI and the interlayer insulating film 120. Further, the central portion PEC of the pixel electrode PE is a portion other than the peripheral edge portion PEP.

  Such an interlayer insulating film 120 can be formed, for example, by depositing an interlayer insulating film material through a mask having an opening corresponding to the partition wall PI and the peripheral edge portion PEP of the pixel electrode PE. Alternatively, the interlayer insulating film 120 may be formed by depositing an interlayer insulating film material on the entire surface of the partition wall PI and the pixel electrode PE and then removing the interlayer insulating film material so as to expose the central portion PEC of the pixel electrode PE. Can also be formed.

  The organic layer ORG is disposed on each of the first organic EL element OLED1 and the second organic EL element OLED2. That is, the organic layer ORG is disposed in the central portion PEC of the pixel electrode PE exposed from the interlayer insulating film 120 and on the interlayer insulating film 120. The organic layer ORG extends to a part of the upper surface PIT of the partition wall PI.

  The counter electrode CE extends to the first organic EL element OLED1 and the second organic EL element OLED2. That is, the counter electrode CE covers the interlayer insulating film 120 and the organic layer ORG.

  In the example shown here, the interlayer insulating film 120 is formed between the side surface PIS of the partition wall PI and the organic layer ORG, between the upper surface PIT of the partition wall PI and the organic layer ORG, and between the upper surface PIT of the partition wall PI and the counter electrode CE. It is arranged between.

  In the central portion PEC of the pixel electrode PE, the organic layer ORG is stacked without being covered with the interlayer insulating film 120, and the counter electrode CE is stacked on the organic layer ORG. For this reason, a current flows between the central portion PEC of the pixel electrode PE and the counter electrode CE, and light emission is possible in the organic layer ORG. In the peripheral edge portion PEP of the pixel electrode PE, since the interlayer insulating film 120 is interposed between the pixel electrode PE and the organic layer ORG, there is no current path and no light is emitted from the organic layer ORG.

  According to such a configuration, even if the partition wall PI peels off from the underlying pixel electrode PE and the insulating film 114 or is displaced, a pixel is formed in the vicinity of the boundary B between the partition wall PI and the pixel electrode PE. Since the interlayer insulating film 120 is interposed between the electrode PE and the organic layer ORG, it is possible to suppress a short circuit between the pixel electrode PE and the counter electrode CE. Therefore, it is possible to suppress the occurrence of light emission failure of the organic EL element OLED due to the short circuit between the pixel electrode PE and the counter electrode CE.

  FIG. 4 is a cross-sectional view schematically illustrating a state where the partition wall PI is peeled from the pixel electrode PE. In FIG. 4, only the main parts necessary for the description are shown.

  A gap GP is formed between the partition wall PI and the pixel electrode PE. This partition wall PI is also peeled off from a part of the insulating film 114. When the organic layer ORG is formed without providing the interlayer insulating film 120 with such a gap GP formed, the organic layer ORG is interrupted in the vicinity of the gap GP. For this reason, the counter electrode CE formed after the organic layer ORG comes into contact with the pixel electrode PE at a portion where the organic layer ORG is interrupted, causing a short circuit between the pixel electrode PE and the counter electrode CE.

  In the present embodiment, the interlayer insulating film 120 is formed after the partition wall PI is formed. At this time, the gap GP formed between the partition wall PI and the pixel electrode PE is covered with the interlayer insulating film 120. The interlayer insulating film 120 is formed as a continuous film without interruption in the vicinity of the gap GP. For this reason, the organic layer ORG formed after the interlayer insulating film 120 is laminated on the interlayer insulating film 120 and the pixel electrode PE without interruption. Therefore, a short circuit between the counter electrode CE and the pixel electrode PE stacked on the organic layer ORG can be suppressed.

  The interlayer insulating film 120 applied in the present embodiment is formed as a continuous film without interruption even if the gap GP is formed between the partition wall PI and the pixel electrode PE. It is desirable that the thickness is sufficient. On the other hand, the thicker the interlayer insulating film 120, the longer the time required to form the interlayer insulating film 120, which is not desirable. Here, the thickness of the interlayer insulating film 120 is the thickness laminated on the upper surface PIT of the partition wall PI.

  The thickness of the interlayer insulating film 120 is equal to or greater than the film thickness of the organic layer ORG and is preferably about twice or less the film thickness of the organic layer ORG, and is desirably in the range of, for example, 50 nm to 100 nm.

  FIG. 5 is a cross-sectional view schematically showing another structure around the partition wall PI. In FIG. 5, only the main parts necessary for explanation are shown.

  The example shown in FIG. 5 is different from the example shown in FIG. 3 in that the interlayer insulating film 120 covers the side surface PIS of the partition wall PI and does not cover the upper surface PIT. That is, the partition wall PI is disposed on the insulating film 114 between the pixel electrodes PE of the adjacent first organic EL elements OLED1 and OLED2. The interlayer insulating film 120 covers each side surface PIS facing the first organic EL element OLED1 and the second organic EL element OLED2 of the partition wall PI. The interlayer insulating film 120 extends from the partition wall PI to the peripheral edge portion PEP of the pixel electrode PE, covers the boundary B between the partition wall PI and the pixel electrode PE, and exposes the central portion PEC of the pixel electrode PE. ing.

  The organic layer ORG is disposed on each of the first organic EL element OLED1 and the second organic EL element OLED2. That is, the organic layer ORG is disposed in the central portion PEC of the pixel electrode PE exposed from the interlayer insulating film 120 and on the interlayer insulating film 120. Further, the organic layer ORG extends on a part of the upper surface PIT of the partition wall PI. That is, the interlayer insulating film 120 is covered with the organic layer ORG, and is surrounded by the side surface PIS of the partition wall PI, the pixel electrode PE, and the organic layer ORG.

  The counter electrode CE extends to the first organic EL element OLED1 and the second organic EL element OLED2. That is, the counter electrode CE covers the upper surface PIT of the partition wall PI and the organic layer ORG.

  Even in such a configuration, the same effect as the example shown in FIG. 3 can be obtained.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the gist of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  In the present embodiment, the organic EL display device has been described as the organic EL device, but the present invention can also be used for organic EL lighting, an organic EL printer head, and the like.

DESCRIPTION OF SYMBOLS 1 ... Display panel 100 ... Array board | substrate 120 ... Interlayer insulation film OLED ... Organic EL element PE ... Pixel electrode PEP ... Peripheral part PEC ... Center part CE ... Counter electrode ORG ... Organic layer PI ... Partition PIS ... Side surface PIT ... Upper surface G ... Gap B ... Boundary

Claims (5)

An insulating substrate;
A pixel electrode disposed above the insulating substrate;
Barrier ribs arranged around the pixel electrode;
An interlayer insulating film extending from the partition wall to the peripheral edge of the pixel electrode and exposing a central portion of the pixel electrode;
An organic layer disposed on the interlayer insulating film and on a central portion of the pixel electrode;
A counter electrode disposed on the organic layer;
An organic EL device comprising: An insulating substrate;
A pixel electrode disposed above the insulating substrate;
Barrier ribs arranged around the pixel electrode;
An organic layer disposed on the pixel electrode;
A counter electrode disposed on the organic layer;
An interlayer insulating film disposed between the partition and the organic layer and in contact with the pixel electrode, and covering a gap formed between the partition and the pixel electrode;
An organic EL device comprising:   The organic EL device according to claim 1, wherein the partition wall has a side surface and an upper surface, the interlayer insulating film covers the side surface, and the counter electrode covers the upper surface of the partition wall and the organic layer. .   The barrier rib has a side surface and an upper surface, the interlayer insulating film covers the side surface and the upper surface, and the counter electrode covers the interlayer insulating film and the organic layer. Organic EL device.   The organic EL device according to claim 1, wherein the interlayer insulating film covers a gap formed between the partition wall and the pixel electrode.

Images