JP4942223B2 - Organic EL device - Google Patents

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. This organic EL element includes a thin film that is easily deteriorated by the influence of moisture and oxygen. For this reason, it is necessary to hermetically seal the organic EL element so as not to be exposed to the atmosphere.

  For example, according to Patent Document 1, an organic electrolysis device is provided that includes a sealing film containing an ultraviolet absorbing material that covers a substrate including an organic EL element, blocks the organic layer from the outside air, and absorbs ultraviolet rays at least in a region on the organic layer. A luminescence device is disclosed. In particular, this sealing film has a film containing an inorganic compound and a film containing an organic compound.

JP 2009-37809 A

  An object of the present invention is to provide an organic EL device capable of suppressing deterioration due to ultraviolet rays.

According to this embodiment,
An insulating substrate, a first switching element and a second switching element disposed above the insulating substrate, respectively, disposed above the first switching element and the second switching element, and reach the first switching element. An insulating film having a first contact hole and a second contact hole reaching the second switching element, and an insulating film disposed on the insulating film and extending to the first contact hole to electrically connect the first switching element. A first pixel electrode that is electrically connected to the second switching element, and the first pixel electrode that is electrically connected to the second switching element, wherein the first pixel electrode is spaced apart from the first pixel electrode on the insulating film. a second pixel electrode, between the second pixel electrode and the first pixel electrode with covering the first pixel electrode and the second pixel electrode A continuous film in which the insulating film was also coated to a position, and the organic layer including a first dopant material and a second dopant material emission performance is changed by ultraviolet irradiation, and a counter electrode covering the organic layer, the organic layer A protective layer containing an ultraviolet absorber that absorbs ultraviolet rays, disposed on the counter electrode located immediately above, a sealing film that is disposed on the protective layer and formed of an inorganic compound, and the sealing A counter substrate disposed above the film; and a filling layer filled between the sealing film and the counter substrate and formed of an ultraviolet curable resin , the first pixel electrode and the counter electrode The organic layer between the first pixel electrode and the second pixel electrode emits light in a color different from that of the organic layer between the second electrode and the counter electrode .

According to this embodiment,
An insulating substrate, a first switching element and a second switching element disposed above the insulating substrate, respectively, disposed above the first switching element and the second switching element, and reach the first switching element. An insulating film having a first contact hole and a second contact hole reaching the second switching element, and an insulating film disposed on the insulating film and extending to the first contact hole to electrically connect the first switching element. A first pixel electrode that is electrically connected to the second switching element, and the first pixel electrode that is electrically connected to the second switching element, wherein the first pixel electrode is spaced apart from the first pixel electrode on the insulating film. a second pixel electrode, between the second pixel electrode and the first pixel electrode with covering the first pixel electrode and the second pixel electrode A continuous film in which the insulating film was also coated to a position, and the organic layer including a first dopant material and a second dopant material emission performance is changed by ultraviolet irradiation, and a counter electrode covering the organic layer, the counter electrode A protective film disposed on the sealing film formed of an inorganic compound; a protective layer that is disposed on the sealing film positioned immediately above the organic layer and contains an ultraviolet absorber that absorbs ultraviolet light; and the protection A counter substrate disposed above the layer; and a filler layer filled between the protective layer and the counter substrate and formed of an ultraviolet curable resin , the first pixel electrode and the counter electrode, An organic EL device is provided in which the organic layer in between emits light in a color different from that of the organic layer between the second pixel electrode and the counter electrode .

  ADVANTAGE OF THE INVENTION According to this invention, the organic electroluminescent apparatus which makes it possible to suppress deterioration by an ultraviolet-ray can be provided.

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. FIG. 2 is a cross-sectional view of a display panel including a switching element and first to third organic EL elements of the organic EL display device according to the first embodiment. FIG. 3 is a diagram showing the relationship of the ultraviolet ray transmittance (I1 / I0) of the protective layer with respect to the film thickness (μm) of the protective layer applied in the present embodiment. FIG. 4 is a cross-sectional view of a display panel including a switching element and first to third organic EL elements of the organic EL display device according to the second embodiment. FIG. 5 is a cross-sectional view schematically showing display panels in Samples B to D of the present embodiment. FIG. 6 is a cross-sectional view schematically showing display panels in samples E to G of the present embodiment. FIG. 7 is a diagram showing the results of an experiment for verifying the influence of the organic EL element on the light emission efficiency due to ultraviolet irradiation.

  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 display device includes a substantially rectangular display panel 1. The display panel 1 includes an array substrate 100 and a counter substrate 200. The array substrate 100 includes a substantially rectangular active area (first area) 102 for displaying an image, and a peripheral area (second area) 104 formed in a frame shape around the active area 102. Yes. The active area 102 of the array substrate 100 includes a plurality of organic EL elements OLED arranged in a matrix.

  The counter substrate 200 faces the organic EL element OLED provided on the array substrate 100 in the active area 102. The counter substrate 200 is a light-transmitting insulating substrate such as a glass substrate or a plastic substrate.

  The display panel 1 further includes a sealing member 300 formed in a frame shape surrounding the active area 102, and a filling layer disposed inside the sealing member 300 between the array substrate 100 and the counter substrate 200. 320 is provided. The seal member 300 and the filling layer 320 are formed of an organic material such as an ultraviolet curable resin, for example. In the present embodiment, ultraviolet rays correspond to electromagnetic waves having a wavelength range of approximately 200 nm to 400 nm.

  The array substrate 100 and the counter substrate 200 are bonded together by a seal member 300 and a filling layer 320. The seal member 300 may be formed on the array substrate 100 side, or may be formed on the counter substrate 200 side. When the filling layer 320 is filled after the sealing member 300 is cured, the array substrate 100 and the counter substrate 200 are bonded to each other before the filling layer 320 is cured, so that the filling layer 320 functions as an adhesive and fills. The layer 320 is bonded to both the array substrate 100 and the counter substrate 200. When such a filling layer 320 is not filled in the entire space between the array substrate 100 and the counter substrate 200, a gap remains in a part thereof, but preferably between the array substrate 100 and the counter substrate 200. All the spaces are filled. The sealing member 300 and the filling layer 320 correspond to a resin layer disposed between the array substrate 100 and the counter substrate 200.

  In the peripheral area 104 of the array substrate 100, an extending portion 110 extending outward from the edge 200E of the counter substrate 200 is formed. The extension part 110 is provided with a connection part 130. The connection unit 130 includes a driving IC chip that supplies signals necessary for driving the organic EL element OLED such as a power source and various control signals, and a flexible printed circuit (hereinafter referred to as FPC). A signal source can be implemented.

  FIG. 2 is a cross-sectional view of the display panel 1 including the switching element SW and the first to third organic EL elements OLED1 to OLED3 of the organic EL display device according to the first embodiment. The first to third organic EL elements OLED1 to OLED3 shown here are top emission types that emit light from the counter substrate 200 side.

  The array substrate 100 includes an insulating substrate 101 having optical transparency such as a glass substrate or a plastic substrate. The switching element SW and the first to third organic EL elements OLED1 to OLED3 are respectively arranged in the active area 102 for displaying an image above the insulating substrate 101.

  A first insulating film 111 is disposed on the insulating substrate 101. Such a first insulating film 111 extends over substantially the entire active area 102. The first insulating film 111 is made of, for example, an inorganic compound such as silicon oxide or silicon nitride.

  On the first insulating film 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 the second insulating film 112. The second insulating film 112 is also disposed on the first insulating film 111. Such a second insulating film 112 extends over substantially the entire active area 102. For example, the second insulating film 112 is formed of an inorganic compound such as silicon oxide or silicon nitride.

  On the second 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 (TFT). The gate electrode G is covered with the third insulating film 113. The third insulating film 113 is also disposed on the second insulating film 112. Such a third insulating film 113 extends over substantially the entire active area 102. The third insulating film 113 is made of, for example, an inorganic compound such as silicon oxide or silicon nitride.

  On the third insulating 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), for example. Yes.

  These source electrode S and drain electrode D are covered with a fourth insulating film 114. The fourth insulating film 114 is also disposed on the third insulating film 113. Such a fourth insulating film 114 extends over substantially the entire active area 102. The fourth insulating film 114 is formed of, for example, an inorganic compound such as silicon oxide or silicon nitride, or an organic compound such as an ultraviolet curable resin or a thermosetting resin.

  The fourth insulating film 114 corresponds to an insulating film disposed above the switching element SW. That is, the fourth insulating film 114 is disposed between the switching element SW and the first to third organic EL elements OLED1 to OLED3. Further, a contact hole CH reaching the switching element SW is formed in the fourth insulating film 114. A part of the drain electrode D of the switching element SW is located at the bottom of the contact hole CH.

  Each pixel electrode PE constituting the first to third organic EL elements OLED1 to OLED3 is disposed on the fourth insulating film 114. Each pixel electrode PE of the first to third organic EL elements OLED1 to OLED3 extends into the contact hole CH and is electrically connected to the drain electrode D of the switching element SW. These pixel electrodes PE correspond to, for example, anodes. The pixel electrodes PE are separated from each other. A part of the fourth insulating film 114 corresponds to an insulating film positioned between adjacent pixel electrodes PE.

  The structure of such a pixel electrode PE is not particularly limited, but in the example shown here, the pixel electrode PE has a two-layer structure in which a reflective layer PER and a transmissive layer PET are laminated. The reflective layer PER is disposed on the fourth insulating film 114. The transmissive layer PET is laminated on the reflective layer PER. The reflective layer PER is made of a conductive material having light reflectivity such as silver (Ag) or aluminum (Al). The transmissive layer PET is made of a light-transmitting conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

  Note that the pixel electrode PE may be a single reflective layer or a single transmissive layer, or may have a laminated structure of three or more layers. In the case of the top emission type in which the first to third organic EL elements OLED1 to OLED3 emit light from the counter substrate 200 side, the pixel electrode PE includes at least the reflective layer PER.

  The organic layer ORG constituting the first to third organic EL elements OLED1 to OLED3 is disposed on each pixel electrode PE. The organic layer ORG is a continuous film that extends over substantially the entire active area 102 and extends over the first to third organic EL elements OLED1 to OLED3. That is, the organic layer ORG covers each pixel electrode PE and also covers the fourth insulating film 114 between the pixel electrodes PE. In other words, the organic layer ORG is provided in common for each pixel electrode PE.

  The organic layer ORG includes at least a light emitting layer (not shown). The organic layer ORG may further include a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and the like. Further, the light emitting layer constituting the organic layer ORG may be formed of a fluorescent material or a phosphorescent material. Here, although referred to as an “organic layer”, a part of the light emitting layer, hole injection layer, hole transport layer, electron injection layer, and electron transport layer included in the organic layer ORG may be formed of an inorganic material. good.

  The counter electrodes CE constituting the first to third organic EL elements OLED1 to OLED3 are arranged on the organic layer ORG. In this example, the counter electrode CE corresponds to a cathode. The counter electrode CE is a continuous film extending over almost the entire active area 102, extends over the first to third organic EL elements OLED1 to OLED3, and covers the organic layer ORG.

  Such a counter electrode CE is formed of, for example, a semi-transmissive layer. The semi-transmissive layer is made of, for example, a conductive material such as magnesium (Mg) / silver (Ag). The counter electrode CE may have a two-layer structure in which a semi-transmissive layer and a transmissive layer are stacked, a transmissive layer single-layer structure, or a semi-transmissive layer single-layer structure. The transmissive layer can be formed of a light-transmitting conductive material such as ITO or IZO. When the first to third organic EL elements OLED1 to OLED3 are of the top emission type, the counter electrode CE does not include a reflective layer.

  A protective layer 150 is disposed on the counter electrode CE. More specifically, the protective layer 150 is disposed on the counter electrode CE located immediately above the organic layer ORG. Such a protective layer 150 is a continuous film extending substantially over the entire active area 102. Further, the protective layer 150 is formed of an organic compound such as an organic EL material that has a light-transmitting property and contains an ultraviolet absorber that absorbs ultraviolet rays. In particular, since the protective layer 150 is disposed above the top emission type organic EL element, that is, on the light emitting side, it is desirable that the protective layer 150 be formed of a material having a high transmittance of light emitted from each organic EL element. Such a protective layer 150 functions as an ultraviolet reduction layer that reduces the ultraviolet rays that reach the first to third organic EL elements OLED1 to OLED3 from the counter substrate 200 side.

  A sealing film 120 is disposed on the protective layer 150. Such a sealing film 120 is a continuous film extending over the entire active area 102. That is, the sealing film 120 covers the protective layer 150 and the first to third organic EL elements OLED1 to OLED3. The sealing film 120 is made of a light-transmitting material that hardly permeates moisture, for example, an inorganic compound such as silicon nitride or silicon oxynitride. Such a sealing film 120 functions as a moisture barrier film that prevents permeation of moisture into the first to third organic EL elements OLED1 to OLED3.

  The counter substrate 200 is disposed above the first to third organic EL elements OLED1 to OLED3, the protective layer 150, and the sealing film 120 formed on the array substrate 100. The counter substrate 200 is a light-transmitting insulating substrate such as a glass substrate or a plastic substrate.

  A filling layer 320 is disposed between the sealing film 120 of the array substrate 100 and the counter substrate 200. The filling layer 320 is formed of, for example, an organic compound such as an ultraviolet curable resin having light transmittance.

  In the present embodiment, the organic layer ORG including the light emitting layer is a continuous film extending over the first to third organic EL elements OLED1 to OLED3, but the light emission of the first to third organic EL elements OLED1 to OLED3. The colors are configured to be different from each other. In the example shown here, the emission color in the organic layer ORG of the first organic EL element OLED1 is red, the emission color in the organic layer ORG of the second organic EL element OLED2 is green, and the third organic EL element OLED3 The emission color in the organic layer ORG is blue.

  Here, the range where the dominant wavelength is 595 nm to 800 nm is defined as the first wavelength range, and the color within the first wavelength range is red. In addition, a range in which the dominant wavelength is longer than 490 nm and shorter than 595 nm is defined as a second wavelength range, and a color in the second wavelength range is green. Furthermore, a range where the dominant wavelength is 400 nm to 490 nm is defined as a third wavelength range, and a color within the third wavelength range is blue.

  Such a configuration can be realized by the following configuration, for example. That is, the organic layers ORG of the first to third organic EL elements OLED1 to OLED3 are, for example, a first dopant material whose emission color is red, a second dopant material whose emission color is green, and a third whose emission color is blue. Contains dopant material. About 1st organic EL element OLED1, a 1st dopant material light-emits and exhibits red. For the second organic EL element OLED2, the first dopant material is quenched, the second dopant material emits light, and exhibits a green color. Regarding the third organic EL element OLED3, the first dopant material and the second dopant material are quenched, and the third dopant material emits light and exhibits blue.

  The form of the organic layer ORG is not particularly limited, and a first light emitting layer containing a first dopant material, a second light emitting layer containing a second dopant material, and a third light emitting layer containing a third dopant material are stacked. It may be a three-layer structure, a two-layer structure in which a first light-emitting layer and a second light-emitting layer are stacked, or a single-layer structure including only the first light-emitting layer. In the case of the two-layer structure, the first light emitting layer may contain not only the first dopant material but also the second dopant material and the third dopant material, and the second light emitting layer includes not only the second dopant material. The first dopant material or the third dopant material may be included. In the case of a single layer structure, the first light emitting layer may include a first dopant material, a second dopant material, and a third dopant material.

  Further, as the first to third dopant materials, the case where a quenching material is applied as a material whose light emission performance is changed by ultraviolet irradiation has been described. However, the emission color is not limited to quenching, and the emission color is changed by ultraviolet irradiation. A material whose light emission performance changes can be applied.

  For example, a material in which the three-dimensional structure of a molecule is changed by irradiation with electromagnetic waves such as ultraviolet rays, and the emission color is changed or quenched can be applied. For example, the case where one dopant material is an isomer of the other dopant material corresponds to this example. Examples of cis isomers and trans isomers as types of isomers will be briefly described. The cis form refers to a three-dimensional structure of a molecule having two side chains (or atomic groups) on the same side with respect to the main skeleton, and the trans form refers to two side chains (or atomic groups) with respect to the main skeleton. Indicates the three-dimensional structure of molecules on opposite sides. Such a dopant material is selected from materials that change from a cis isomer to a trans isomer by irradiation with electromagnetic waves such as ultraviolet rays, or change from a trans isomer to a cis isomer. Examples of such a material include a photochromic material. It is done.

  Examples of other isomers include materials referred to as light-converted proteins or fluorescent proteins. For example, among fluorescent proteins, there are materials that are activated from a quenching state when irradiated with electromagnetic waves such as ultraviolet rays, and materials that are converted from one emission wavelength to another emission wavelength. The present invention can be applied as a dopant material.

  Further, a material in which the dopant material contained in the light emitting layer and the additive or the host material are chemically bonded to each other by irradiation of electromagnetic waves such as ultraviolet rays to change or quench the emission color is also applicable.

  The display panel 1 shown in FIG. 2 employs a configuration in which the partition walls for partitioning the first to third organic EL elements OLED1 to OLED3 are omitted. Therefore, the entire pixel electrode including the periphery of each pixel electrode PE is in contact with the organic layer ORG. Moreover, since the organic layer ORG is a continuous film extending over the first to third organic EL elements OLED1 to OLED3, the organic layer ORG is also the fourth insulating film 114 positioned between the adjacent pixel electrodes PE. It touches.

  Although not shown, the display panel 1 may include a partition formed of an insulating material of an inorganic compound or an insulating material of an organic compound. In this case, the partition corresponds to an insulating film positioned between adjacent pixel electrodes PE. Therefore, the organic layer ORG, which is a continuous film extending over the first to third organic EL elements OLED1 to OLED3, is in contact with each of the pixel electrodes PE and the partition walls.

  According to the first embodiment, the protective layer 150 that is an ultraviolet reduction layer is disposed between the top emission type first to third organic EL elements OLED1 to OLED3 and the counter substrate 200. For this reason, when external light is incident on the first to third organic EL elements OLED1 to OLED3 through the counter substrate 200, the first to third organic EL elements OLED1 to OLED3 caused by ultraviolet rays contained in the external light. It becomes possible to suppress deterioration, particularly deterioration of the light emitting layer included in the organic layer ORG.

  In particular, as described in the present embodiment, the organic layer ORG including the light emitting layer is a continuous film extending over the first to third organic EL elements OLED1 to OLED3, but the first to third organic EL elements. In the configuration in which the emission colors of the OLEDs 1 to 3 are different from each other, the organic EL material contained in the organic layer ORG tends to absorb and change the property of the ultraviolet rays and is sensitive to the ultraviolet rays. For this reason, it is necessary to protect the organic layer ORG from ultraviolet rays after irradiation with ultraviolet rays in order to control the emission color.

  Therefore, by disposing the protective layer 150 above the first to third organic EL elements OLED1 to OLED3, the organic layers ORG of the first to third organic EL elements OLED1 to OLED3 can be protected from ultraviolet rays. .

  In addition, as described in the present embodiment, the filling layer 320 disposed between the sealing film 120 positioned immediately above the first to third organic EL elements OLED1 to OLED3 and the counter substrate 200 is an ultraviolet curable resin. It is necessary to protect the organic layer ORG from the ultraviolet rays irradiated for the curing process.

  Therefore, the organic layer ORG of the first to third organic EL elements OLED1 to OLED3 is protected from ultraviolet rays by disposing the protective layer 150 between the first to third organic EL elements OLED1 to OLED3 and the filling layer 320. It becomes possible.

  In general, the light transmittance (ratio of transmitted light intensity to incident light intensity) is: incident light intensity I0, transmitted light intensity I1, angular frequency of light ω, wavelength λ, absorption coefficient κ, refractive index Where n is the light speed, C is the light velocity, and Z is the film thickness, I1 / I0 = exp (−2ωκ / C · Z) = exp (−4πκ / λ / n · Z). In order to increase the amount of ultraviolet light absorbed by the protective layer 150 disposed above the counter electrode CE as much as possible, that is, to minimize the amount of ultraviolet light transmitted through the protective layer 150, κ / n · Z of the protective layer 150 should be as small as possible. It needs to be bigger. Therefore, by adjusting the film thickness Z of the protective layer 150, it is possible to reduce damage to the organic layer ORG caused by ultraviolet rays.

  In particular, it is preferable that the protective layer 150 is formed of an organic EL material by utilizing the characteristic that the organic EL material easily absorbs ultraviolet rays. The protective layer 150 made of such a material can be formed by a technique such as coating or vapor deposition.

  FIG. 3 is a diagram showing the relationship of the ultraviolet transmittance (I1 / I0) of the protective layer 150 with respect to the film thickness (μm) of the protective layer 150. Here, the refractive index n of the protective layer 150 is 2.02, the absorption coefficient κ of the protective layer 150 is 0.18, and the wavelength λ of ultraviolet light incident on the protective layer 150 is 365 nm.

  As shown in the figure, it can be confirmed that the greater the film thickness of the protective layer 150, the lower the ultraviolet transmittance. In particular, in order to set the transmittance of ultraviolet rays that pass through the protective layer 150 to 50% or less, the thickness of the protective layer 150 is preferably about 0.2 μm or more.

  Next, a second embodiment will be described.

  FIG. 4 is a cross-sectional view of the display panel 1 including the switching element SW and the first to third organic EL elements OLED1 to OLED3 of the organic EL display device according to the second embodiment. Compared with the example shown in FIG. 2, the example shown in FIG. 4 replaces the protective layer 150 between the counter electrode CE and the sealing film 120, and between the sealing film 120 and the filling layer 320. The difference is that the protective layer 150 is disposed. In addition, about the same structure as the example shown in FIG. 2, the same referential mark is attached | subjected and detailed description is abbreviate | omitted.

  Between the insulating substrate 101 of the array substrate 100 and the first to third organic EL elements OLED1 to OLED3, the first insulating film 111, the second insulating film 112, the third insulating film 113, the fourth insulating film 114, and the switching are provided. Elements SW and the like are arranged. In the fourth insulating film 114, a contact hole CH reaching the drain electrode D of the switching element SW is formed.

  Each pixel electrode PE constituting the first to third organic EL elements OLED1 to OLED3 is disposed on the fourth insulating film 114. Each of the pixel electrodes PE of the first to third organic EL elements OLED1 to OLED3 extends into the contact hole CH and is electrically connected to the drain electrode D of the switching element SW. Each pixel electrode PE is formed of a reflective layer PER disposed on the fourth insulating film 114 and a transmissive layer PET disposed on the reflective layer PER.

  The organic layer ORG constituting the first to third organic EL elements OLED1 to OLED3 is disposed on each pixel electrode PE. The organic layer ORG is a continuous film that extends over substantially the entire active area 102 and extends over the first to third organic EL elements OLED1 to OLED3. That is, the organic layer ORG covers the fourth insulating film 114 between each pixel electrode PE and the pixel electrode PE.

  The counter electrodes CE constituting the first to third organic EL elements OLED1 to OLED3 are arranged on the organic layer ORG. The counter electrode CE is a continuous film extending over almost the entire active area 102, extends over the first to third organic EL elements OLED1 to OLED3, and covers the organic layer ORG.

  A sealing film 120 is disposed on the counter electrode CE. Such a sealing film 120 is a continuous film extending over the entire active area 102. That is, the sealing film 120 covers the first to third organic EL elements OLED1 to OLED3.

  A protective layer 150 is disposed on the sealing film 120. More specifically, the protective layer 150 is disposed on the sealing film 120 positioned immediately above the organic layer ORG. Such a protective layer 150 is a continuous film extending substantially over the entire active area 102.

  A filler layer 320 is disposed between the protective layer 150 and the counter substrate 200.

  In the second embodiment, the same effect as that of the first embodiment can be obtained.

  Next, for the organic EL device according to the present embodiment, an experiment was conducted to verify the influence on the light emission efficiency of the organic EL element OLED by ultraviolet irradiation.

  The switching element SW, the first insulating film 111, the second insulating film 112, the third insulating film 113, the fourth insulating film 114, and the pixel electrode PE are formed on a first mother substrate made of a 400 mm × 500 mm rectangular glass substrate. A reflective layer PER and a transmissive layer PET were formed. In the first mother substrate, 24 regions for forming the array substrate 100 in which the diagonal dimension of the active area 102 is 3.5 type are formed. The switching element SW is configured as a low-temperature polysilicon TFT having a polysilicon thin film as a semiconductor layer. Seven such first mother substrates (A, B, C, D, E, F, G) were prepared.

  Subsequently, the seven first mother substrates of Samples A to G are respectively set in a resistance heating type organic EL film forming apparatus, and a hole transport layer is formed as an organic EL material on the pixel electrode PE. On the transport layer, a red light emitting layer containing a first dopant material that emits red light is formed over the entire surface where the first to third organic EL elements OLED1 to OLED3 are formed. A red light emitting layer formed in these regions by irradiating the region where the second organic EL element OLED2 and the third organic EL element OLED3 are formed through a photomask with ultraviolet light having a dominant wavelength of 365 nm. The first dopant material contained in the liquid crystal was prevented from emitting light.

  Thereafter, each of the first mother substrates of Samples A to G is set again in the organic EL film forming apparatus, and the regions where the first to third organic EL elements OLED1 to OLED3 are respectively formed on the red light emitting layer. After forming a green light emitting layer containing a second dopant material that emits green light over the entire surface, the green light emitting layer is once taken out from the organic EL film forming apparatus, and the main wavelength is formed in a region where the third organic EL element OLED3 is formed through a photomask. Was irradiated with ultraviolet light of 365 nm so that the second dopant material contained in the green light emitting layer formed in this region did not emit light.

  Further, each of the first mother substrates of Samples A to G is set again in the organic EL film forming apparatus, and the first to third organic EL elements OLED1 to OLED3 are formed on the green light emitting layer. After forming a blue light-emitting layer containing a third dopant material that emits blue light over the entire surface, an electron transport layer is formed on the blue light-emitting layer, and an electron injection layer is formed on the electron transport layer, Thereafter, a counter electrode CE was formed on the electron injection layer using magnesium / silver.

  Subsequently, for the first mother substrates of Samples A to G, the sealing film 120 and the protective layer 150 were formed on the counter electrode CE according to the following procedure.

  That is, for the first mother substrate of Sample A, a thin film made of silicon nitride (SiN) was formed as a sealing film 120 with a film thickness of 1 μm on the counter electrode CE using the plasma CVD method. Since the sample A does not include a member corresponding to the protective layer 150, the value of (κ / n · Z) is zero.

  For the first mother substrates of Samples B to D, after forming the protective layer 150 on the counter electrode CE using the organic EL material using the resistance heating type organic EL film forming apparatus, A thin film made of silicon nitride (SiN) was formed to a thickness of 1 μm as a sealing film 120 on the top using a plasma CVD method.

  For sample B, the thickness of the protective layer 150 was 100 nm. The value of (κ / n · Z) in Sample B is 8.91 nm. For sample C, the thickness of the protective layer 150 was 200 nm. The value of (κ / n · Z) in sample C is 17.82 nm. For sample D, the thickness of the protective layer 150 was 300 nm. The value of (κ / n · Z) in sample D is 26.73 nm.

  For the first mother substrates of Samples E to G, a thin film made of silicon nitride (SiN) as the sealing film 120 on the counter electrode CE using a plasma CVD method using a resistance heating type organic EL film forming apparatus. Was formed to a thickness of 1 μm, and then a protective layer 150 was formed on the sealing film 120 using an organic EL material.

  For sample E, the thickness of the protective layer 150 was 100 nm. The value of (κ / n · Z) in Sample E is 8.91 nm. For sample F, the thickness of the protective layer 150 was 200 nm. The value of (κ / n · Z) in Sample F is 17.82 nm. For sample G, the thickness of the protective layer 150 was 300 nm. The value of (κ / n · Z) in sample G is 26.73 nm.

  The organic EL material used as the protective layer 150 of Samples B to G had an absorption coefficient κ of 0.18 for ultraviolet light having a wavelength of 365 nm and a refractive index n of 2.02.

  On the other hand, a second mother substrate was prepared from a glass substrate as the counter substrate 200. On each second mother substrate, an ultraviolet curable resin is applied as a seal member 300 using a dispenser, and an appropriate amount of an ultraviolet curable resin for forming the filling layer 320 is dropped inside the seal member 300. did. These second mother substrates are bonded to the first mother substrates of the samples A to G in the vacuum chamber.

Thereafter, the ultraviolet curable resin to be the sealing member 300 and the ultraviolet curable resin to be the filling layer 320 were cured by being irradiated with ultraviolet rays. At this time, the main wavelength of the irradiated ultraviolet light was 365 nm, and the energy at a wavelength of 365 nm was 5 J / cm ² .

  Then, the substrate pair in which the first mother substrate and the second mother substrate were bonded together was cleaved into 24 display panels 1, and then a signal supply source was mounted on each display panel 1.

  Samples B to D thus formed correspond to the first embodiment described above.

  FIG. 5 is a cross-sectional view schematically showing the display panel 1 in samples B to D. In FIG. 5, the array substrate 100 includes the first insulating film 111, the second insulating film 112, the third insulating film 113, the fourth insulating film 114, the switching element SW, and the like as already described. The illustration is omitted.

  In the display panel 1, each pixel electrode PE is covered with an organic layer ORG, and the organic layer ORG is covered with a counter electrode CE. A protective layer 150 is disposed on the counter electrode CE. The counter electrode CE and the protective layer 150 are covered with the sealing film 120. A filling layer 320 is disposed inside the sealing member 300 and between the sealing film 120 and the counter substrate 200.

  Further, the formed samples E to G correspond to the above-described second embodiment.

  FIG. 6 is a cross-sectional view schematically showing the display panel 1 in samples E to G. In FIG. 6, the array substrate 100 includes a first insulating film 111, a second insulating film 112, a third insulating film 113, a fourth insulating film 114, a switching element SW, and the like, which are not shown. .

  In the display panel 1, each pixel electrode PE is covered with an organic layer ORG, and the organic layer ORG is covered with a counter electrode CE. The counter electrode CE is covered with the sealing film 120. A protective layer 150 is disposed on the sealing film 120. A filling layer 320 is disposed between the protective layer 150 and the counter substrate 200 on the inner side surrounded by the seal member 300.

  Subsequently, for each of samples A to G, the light emission efficiency (cd / A) of 24 display panels 1 at a current value of 0.5 mA was measured, and the average value of the light emission efficiency of each sample was calculated. The result is shown in FIG.

  For sample A that does not include the protective layer 150, the organic layers ORG of the first to third organic EL elements OLED1 to OLED3 are damaged by the influence of ultraviolet rays irradiated in the process of forming the sealing member 300 and the filling layer 320 ing. For this reason, luminous efficiency was remarkably low, and the average value was 2.1 cd / A.

  Samples B to G provided with the protective layer 150 have a higher luminous efficiency than Sample A because the influence of ultraviolet rays is reduced. The average value of the luminous efficiency of Sample B was 3.2 cd / A. The average value of the luminous efficiency of sample C was 4.5 cd / A. The average value of the luminous efficiency of sample D was 4.8 cd / A. The average value of the luminous efficiency of sample E was 3.1 cd / A. The average value of the luminous efficiency of sample F was 4.6 cd / A. The average value of the luminous efficiency of sample G was 4.9 cd / A.

  In addition, according to the comparison of Sample B, Sample C, and Sample D, or the comparison of Sample E, Sample F, and Sample G, the first to third organic layers due to ultraviolet rays are increased as the protective layer 150 is thicker. It was confirmed that deterioration of the EL elements OLED1 to OLED3 can be suppressed and high luminous efficiency can be obtained.

  Furthermore, according to the comparison between the sample B and the sample E, the comparison between the sample C and the sample F, or the comparison between the sample D and the sample G, the same luminous efficiency is obtained. It was confirmed that the deterioration of the first to third organic EL elements OLED1 to OLED3 due to ultraviolet rays can be suppressed regardless of the order in which the film 120 and the protective layer 150 are formed.

  As described above, by disposing the protective layer 150 that absorbs ultraviolet rays between the counter electrode CE and the sealing film 120 or between the sealing film 120 and the filling layer 320, a display panel having high light emission efficiency. 1 can be provided.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit 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 OLED1 ... 1st organic EL element OLED2 ... 2nd organic EL element OLED3 ... 3rd organic EL element 120 ... Sealing film 150 ... Protective layer 200 ... Opposite substrate 300 ... Sealing member 320 ... Filling layer SW ... Switching element PE ... Pixel electrode PER ... Reflective layer PET ... Transmission layer ORG ... Organic layer CE ... Counter electrode

Claims (8)

An insulating substrate;
A first switching element and a second switching element respectively disposed above the insulating substrate ;
An insulating film disposed above the first switching element and the second switching element and having a first contact hole reaching the first switching element and a second contact hole reaching the second switching element;
A first pixel electrode disposed on the insulating film, extending to the first contact hole and electrically connected to the first switching element ;
A second pixel electrode disposed on the insulating film and spaced apart from the first pixel electrode, extending to the second contact hole and electrically connected to the second switching element ;
A continuous film covering the first pixel electrode and the second pixel electrode and also covering the insulating film located between the first pixel electrode and the second pixel electrode, and the light emission performance is changed by ultraviolet irradiation. An organic layer comprising a first dopant material and a second dopant material ,
A counter electrode covering the organic layer;
A protective layer that is disposed on the counter electrode located directly above the organic layer and contains an ultraviolet absorber that absorbs ultraviolet rays;
A sealing film disposed on the protective layer and formed of an inorganic compound ;
A counter substrate disposed above the sealing film;
A filling layer filled between the sealing film and the counter substrate and formed of an ultraviolet curable resin ;
Equipped with a,
The organic EL device , wherein the organic layer between the first pixel electrode and the counter electrode emits light in a color different from that of the organic layer between the second pixel electrode and the counter electrode . An insulating substrate;
A first switching element and a second switching element respectively disposed above the insulating substrate ;
An insulating film disposed above the first switching element and the second switching element and having a first contact hole reaching the first switching element and a second contact hole reaching the second switching element;
A first pixel electrode disposed on the insulating film, extending to the first contact hole and electrically connected to the first switching element ;
A second pixel electrode disposed on the insulating film and spaced apart from the first pixel electrode, extending to the second contact hole and electrically connected to the second switching element ;
A continuous film covering the first pixel electrode and the second pixel electrode and also covering the insulating film located between the first pixel electrode and the second pixel electrode, and the light emission performance is changed by ultraviolet irradiation. An organic layer comprising a first dopant material and a second dopant material ,
A counter electrode covering the organic layer;
A sealing film disposed on the counter electrode and formed of an inorganic compound ;
A protective layer that is disposed on the sealing film located immediately above the organic layer and contains an ultraviolet absorber that absorbs ultraviolet rays;
A counter substrate disposed above the protective layer;
A filling layer filled between the protective layer and the counter substrate and formed of an ultraviolet curable resin ;
Equipped with a,
The organic EL device , wherein the organic layer between the first pixel electrode and the counter electrode emits light in a color different from that of the organic layer between the second pixel electrode and the counter electrode . The organic EL device according to claim 1 , wherein the protective layer protects the organic layer from ultraviolet rays when the filling layer is irradiated with ultraviolet rays .   The organic EL device according to claim 1, wherein the protective layer is formed of an organic EL material. The organic layer includes a first light-emitting layer including the first dopant material, and a second light-emitting layer stacked on the first light-emitting layer and including the second dopant material. The organic EL device described in 1. The organic EL device according to claim 3, wherein the organic layer includes a single-layer light emitting layer including the first dopant material and the second dopant material. The first emission color of the first dopant material has a longer wavelength than the second emission color of the second dopant material, and the organic layer between the first pixel electrode and the counter electrode is the first dopant material. The organic layer between the second pixel electrode and the counter electrode emits light and the second dopant material emits light in the organic layer between the second pixel electrode and the counter electrode. Organic EL device. The organic layer is in contact with the first switching element in the first contact hole of the first pixel electrode and in contact with the second switching element in the second contact hole of the second pixel electrode. The organic EL device according to claim 7, wherein the covered portion is covered.

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