JP2009301731A - Organic light emitting device and method for manufacturing organic light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic light emitting device for enhancing a light extraction efficiency by providing a film thickness set by a simplified optical interference design and provide a method for manufacturing the organic light emitting device. <P>SOLUTION: The organic light emitting device 30 includes a light transmitting substrate 1, a light transmitting anode layer 2 arranged on the substrate 1, a plurality of organic light emitting layers (27, 28, 29) arranged on the anode layer 2 and having at least hole transfer layers (6, 9, 12), light emitting parts (7, 10, 13) and electron transfer layers (8, 11, 14) laminated one by one from a side of the anode electrode layer 2, electric load generating layers (15, 16) interposed between the organic light emitting layers (27, 28, 29), and a cathode layer 3 arranged on the organic light emitting layer 29 located on an uppermost part in a lamination direction. Each film thickness of each layer between the anode layer 2 and the cathode layer 3 is set so that an optical path distance from a light emitting position of each of the light emitting parts (7, 10) to the cathode layer 3 may become an odd number times of a quarter of a light emitting wavelength of each of the light emitting parts (7, 10). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic light-emitting device and a method for manufacturing the organic light-emitting device, and in particular, in an organic light-emitting device having a structure in which a plurality of organic light-emitting layers are stacked, the optical film thickness of the organic light-emitting layer is controlled and the light extraction efficiency is increased. The present invention relates to an improved organic light emitting device and a method for manufacturing the organic light emitting device.

  2. Description of the Related Art In recent years, organic light-emitting devices such as display devices such as FPD (Flat Panel Display) and illumination devices such as illumination lamps have been developed for practical use using organic EL (EL) elements. . In this organic EL element, an organic EL layer including an organic light emitting layer is sandwiched between a pair of opposed electrodes, and a voltage is applied between the electrodes to cause a current to flow through the organic EL layer to emit light. Recently, in order to obtain high brightness, a structure called Multi Photon Emission (MPE) in which a plurality of organic EL layers are stacked via a charge generation layer has been proposed (for example, Patent Documents). 1).

  In the conventional MPE type organic EL element, as shown in FIG. 7, an anode 51 made of a transparent electrode is formed on a substrate 50 made of transparent glass. A first organic light emitting layer 101 in which a hole transport layer 54, a light emitting portion 55, and an electron transport layer 56 are laminated is disposed on the anode 51. Then, a charge generation layer 57 is formed so as to cover the electron transport layer 56, and the second organic light emitting layer 102 in which the hole transport layer 58, the light emitting portion 59, and the electron transport layer 60 are laminated on the charge generation layer 57. Is formed. Further, a third organic light emitting layer 103 in which a hole transport layer 62, a light emitting unit 63, and an electron transport layer 64 are stacked is disposed via the charge generation layer 61. A cathode 52 facing the anode 51 is formed on the third organic light emitting layer 103 with a metal material.

  The light emitted from each light emitting section (55, 59, 63) includes light (L7, L8, L9) directly emitted from the substrate 50, and light (L1, L9) reflected from the cathode 52 and then emitted from the substrate 50. L2, L3), or after repeated reflection at each layer, there is light emitted from the substrate 50, and these lights interfere with each other and are extracted from the substrate 50 side.

Therefore, in the MPE type organic EL element, it is necessary to appropriately set each film thickness in order to take out more intense light in consideration of optical interference of light emitted from each light emitting section (55, 59, 63). was there.
JP 2003-045676 A

  Conventionally, in the interference design of this film thickness, light (L1, L2, L3) reflected by the cathode 52 and light reflected by the anode 51 of the transparent electrode (with respect to the light emitted from each light emitting portion (55, 59, 63)) ( L4, L5, L6) and the optical path calculation were made so as not to cancel each other, and the film thickness of each layer was determined. That is, the optical distance between the light emission position and the cathode 52 is adjusted to an odd multiple of one quarter of the light emission wavelength, and the optical distance between the light emission position and the anode 51 is adjusted to an even multiple of one quarter of the light emission wavelength. Thus, the emission wavelength can be emphasized and extracted from the substrate 50 side.

  However, when the number of organic light emitting layers is increased, the optical path calculation becomes complicated as the number of layers increases, so that there is a problem that optical path adjustment becomes difficult.

  An object of the present invention is to provide an organic light-emitting device and a method for manufacturing the organic light-emitting device that can increase the light extraction efficiency by having a film thickness set by a simplified optical interference design.

  According to one aspect of the present invention for achieving the above object, a light transmissive substrate, a light transmissive anode layer disposed on the substrate, and a stacked layer disposed on the anode layer, A plurality of organic light emitting layers in which at least a hole transport layer, a light emitting portion and an electron transport layer are sequentially laminated from the anode layer side; a charge generation layer disposed between the organic light emitting layers; and an uppermost portion in the stacking direction A cathode layer disposed on the organic light emitting layer, and the thickness of each layer sandwiched between the anode layer and the cathode layer is determined from the light emitting position of the organic light emitting layer in contact with the anode layer. The optical distance from the light emitting position of each light emitting part to the cathode layer is set to a predetermined film thickness from the light emitting position of the organic light emitting layer in contact with the cathode layer to the cathode layer. To be an odd multiple of one quarter of the emission wavelength of each light emitting section. The organic light emitting device is provided which is characterized in that it is a constant.

  According to another aspect of the present invention, each thickness of the organic light emitting layer of an organic light emitting device having a configuration in which a plurality of organic light emitting layers are laminated between an anode layer and a cathode layer formed on a substrate, Each of the light emitting units has a predetermined film thickness from the light emitting position of the organic light emitting layer in contact with the layer to the anode layer and the light emitting position of the organic light emitting layer in contact with the cathode layer to the cathode layer. A step of setting the optical distance from the light emitting position to the cathode layer to be an odd multiple of one-fourth of the light emitting wavelength of each light emitting portion, and forming the anode layer on the substrate A step of forming a plurality of the organic light emitting layers with the film thickness through a charge generation layer, a step of forming the cathode layer after forming an insulating layer, and an anode terminal through a sealing member with a sealing plate And bonding and sealing to the substrate so that the cathode terminal is exposed; Method of manufacturing an organic light emitting device having is provided.

  According to the organic light emitting device and the method for manufacturing the organic light emitting device of the present invention, the light extraction efficiency can be increased by having the film thickness set by the simplified optical interference design.

  Hereinafter, an organic light emitting device according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, differ from actual ones, and also include portions having different dimensional relationships and ratios between the drawings.

[First embodiment]
(Structure of organic light-emitting device)
As shown in FIGS. 1 and 2, the organic light emitting device 30 according to the first embodiment of the present invention includes a light transmissive substrate 1, and a light transmissive anode layer 2 disposed on the substrate 1. At least the hole transport layer (6, 9, 12), the light emitting part (7, 10, 13) and the electron transport layer (8, 11, 14) arranged on the anode layer 2 from the anode layer 2 side. ) Sequentially stacked, a plurality of organic light emitting layers (27, 28, 29), a charge generation layer (15, 16) disposed between the organic light emitting layers (27, 28, 29), and a stacking direction And the cathode layer 3 disposed on the organic light emitting layer 29 disposed on the uppermost portion.

  The film thickness of each layer sandwiched between the anode layer 2 and the cathode layer 3 is the film thickness from the light emitting position of the organic light emitting layer 27 in contact with the anode layer 2 to the anode layer 2 and the light emitting position of the organic light emitting layer 29 in contact with the cathode layer 3. From the light emitting position of each light emitting part (7, 10) to the cathode layer 3 is a quarter of the emission wavelength of each light emitting part (7, 10). It is set to be an odd multiple of 1.

In the present embodiment, the thickness of each layer constituting the organic light emitting layer (27, 28, 29) sandwiched between the anode layer 2 and the cathode layer 3 is expressed by the following formulas (1) to (5):
_{s 1 = (2i-1)} λ 1/4 ··· (1)
_{s 2 = (2l-1)} λ 2/4 ··· (2)
...
s _k = (2m−1) λ _k / 4 (3)
...
s _J-1 = (2n-1) λ _J-1 / 4 (4)
h = a + b ₁ + b ₂ +... + b _k +... b _J−1 + c (5)
However, the position of the organic light emitting layer (27, 28, 29) is counted in the stacking order from the anode layer 2 side, and s _k : the k th organic at the peak wavelength of the light emitted from the k th organic light emitting layer. Optical distance from the light emitting position of the light emitting layer to the cathode layer 3, λ _k : peak wavelength of light emitted from the kth organic light emitting layer, h: film from the surface of the anode layer 2 in contact with the substrate 1 to the cathode layer 3 Thickness, a: predetermined film thickness from the light emitting position of the first organic light emitting layer to the surface of the anode layer 2 in contact with the substrate 1, b _k : (k + 1) th light emitting position of the kth organic light emitting layer The thickness of the organic light emitting layer to the light emitting position, c: the predetermined film thickness from the light emitting position of the Jth organic light emitting layer to the cathode layer 3, k: an integer from 1 to J, J: total organic light emitting layer The number of layers, i, l, m, n: an integer of 1 or more is satisfied.

  In the present embodiment, the organic light emitting layer (27, 28, 29) includes a hole transport layer (6, 9, 12), a light emitting portion (7, 10, 13) that emits monochromatic light, and an electron transport layer (8, 11, 14), and the organic light emitting layer 27 may include the hole injection layer 5. The number of the organic light emitting layers (27, 28, 29) is not particularly limited as long as it is plural, and can be appropriately set.

  In the present embodiment, the organic light emitting layer (27, 28, 29) may be configured as a laminate of three layers with the charge generation layer (15, 16) interposed therebetween as shown in FIG. In the following description, it is assumed that there are three organic light emitting layers (27, 28, 29), the organic light emitting layer 27 emits blue light, the organic light emitting layer 28 emits green light, and the organic light emitting layer 29 emits red light.

  In the present embodiment, the film thicknesses a and c are separately set by a method to be described later, and the film thicknesses of the organic light emitting layers (27, 28, 29) are set to the first blue light emitting part 7 and the second light emitting part 7, respectively. The light emitted from the green light emitting unit 10 is set based on the optical path calculation of the light (L1, L2) reflected by the cathode layer 3.

  That is, the respective film thicknesses are the following (1), (2) and (11) when the total number J of the organic light emitting layers (27, 28, 29) is 3 in the above formulas (1) to (5). Set to satisfy the expression.

_{s 1 = (2i-1)} λ 1/4 ··· (1)
_{s 2 = (2l-1)} λ 2/4 ··· (2)
h = a + b ₁ + b ₂ + c (11)
i and l are integers of 1 or more, preferably 1 to 10, and more preferably 1 to 5.

Specifically, the optical distances s ₁ and s ₂ are obtained by using the refractive index of each layer corresponding to the film thickness of each layer and the peak wavelength of the light emitted from each light emitting section (7, 10), (12) And (13).

s ₁ = d ₄ · η ₄ + d ₅ · η ₅ ++ d ₆ · η ₆ + d ₇ · η ₃ + d ₈ · η ₄ + d ₉ · η ₅ + d ₁₀ · η ₆ + d ₁₁ · η ₃ + d ₁₂ · η ₇ + d ₁₃・ Η ₅ (12)
s ₂ = d ₈ · η ₄ + d ₉ · η ₅ + d ₁₀ · η ₆ + d ₁₁ · η ₃ + d ₁₂ · η ₇ + d ₁₃ · η ₅ (13)
Further, a, b ₁ , b ₂ and c are specifically given by the equations (14) to (17).

a = d ₁ + d ₂ + d ₃ (14)
b ₁ = d ₄ + d ₅ + d ₆ + d ₇ (15)
b ₂ = d ₈ + d ₉ + d ₁₀ + d ₁₁ (16)
c = d ₁₂ + d ₁₃ (17)
Here, although the light emission position in each light emission part (7,10,13) changes with substances of a light emission part, in this Embodiment, as shown in FIG. 2, each light emission part (7,10,13) is shown. ) Of the anode layer 2 side surface. λ ₁ is the peak wavelength of blue emitted light, for example, about 430 to 480 nm, and λ ₂ is the peak wavelength of green emitted light, for example, about 530 to 580 nm. d _{1 to} d ₁₃ are film thicknesses corresponding to the respective layers. η ₁ is the refractive index of the anode layer 2, for example, about 2, and η ₂ is the refractive index of the hole injection layer 5, for example, about 1.8 to 2.0, and η ₃ is hole transport. The refractive index of the layer (6, 9, 12), for example, about 1.8 to 2.0, and η ₄ is the refractive index of the light emitting part (7, 10), for example, about 1.8-2. about .0, eta ₅ is the refractive index of the electron transport layer (8, 11 and 14), for example, about 1.8 to 2.0, eta ₆ represents a refractive index in the charge generation layer (15, 16) For example, about 1.8 to 2.0, and η ₇ is the refractive index of the light emitting portion 13, for example, about 1.7 to 1.9.

  In the present embodiment, the highest light emission efficiency can be obtained when the optical distance from each light emission position to the cathode layer 3 is an odd multiple of one-fourth of the light emission wavelength. That is, light traveling through a region having a high refractive index does not shift in phase when reflected at the interface with the region having a low refractive index. However, the phase of light traveling through the region having a low refractive index is shifted by half a wavelength when reflected at the interface with the region having a high refractive index. Accordingly, the light reflected by the cathode layer 3 having a refractive index larger than that of the organic light emitting layer (27, 28, 29) is shifted by a half wavelength, so that the light emitted at each light emitting position is reflected by the cathode layer 3 and is the original light emitting position. By making the optical distance to return to an odd multiple of a half wavelength, that is, the optical distance to the cathode layer 3 an odd multiple of a quarter of the emission wavelength, the phases match and the emitted light can be intensified. .

In the present embodiment, the film thicknesses a and c are the layers on the substrate 1 side from the light emitting portion 7 of the organic light emitting layer 27 in contact with the substrate 1 side, that is, the hole transport layer 6 and the hole injection layer 5, and the transparent electrode. A layer on the cathode layer 3 side from the light emitting portion 13 including the light emitting portion 13 of the organic light emitting layer 29 in contact with the film thickness a (= d ₁ + d ₂ + d ₃ ) of the certain anode layer 2 and the cathode layer 3 side, that is, the light emitting portion 13. And the film thickness c (= d ₁₂ + d ₁₃ ) for the electron transport layer 14. The film thicknesses a and c are set by adjusting the film thicknesses so that the power efficiency [lm / W] is maximized by examining the element characteristics with each organic light emitting layer (27, 29) in a single state. To do.

 FIG. 3 shows a configuration of each organic light emitting layer (27, 28, 29) for adjusting the film thickness, and FIG. 4 shows an element of each organic light emitting layer (27, 28, 29) when the film thickness is adjusted. The characteristic results are shown.

For example, each thickness a (= d ₁ + d ₂ + d ₃ ) of the organic light emitting layer 27 obtained by the adjustment is about 50 to 300 nm for d ₁ , about 0 to 100 nm for d ₂ , and about 20 to about ₃ for d _3. is 100 nm, the thickness _c of the organic light-emitting layer _{29 (= d 12 + d 13} ) _{is, d 12} is about 10 to 60 _{nm, d 13} was about 10 to 600 nm,. Although FIG. 3 shows the hole injection layer 5, when examining the device characteristics of the organic light emitting layer (28, 29) stacked above the organic light emitting layer 27 in contact with the anode layer 2, The hole injection layer 5 may not be used.

The device characteristics of the organic light emitting layers (27, 28, 29) obtained by the adjustment are as follows. For the blue organic light emitting layer 27, luminance = 1000 [d / m ² ] and power efficiency = 12 [lm / W], current efficiency = 16 [cd / A], and for the green organic light emitting layer 28, luminance = 1000 [d / m ² ], power efficiency = 17 [lm / W], current efficiency = 23 [cd] / A] and the red organic light-emitting layer 29 had luminance = 1000 [d / m ² ], power efficiency = 9 [lm / W], and current efficiency = 11 [cd / A].

The film thicknesses d _{4 to} d ₁₁ of the respective organic light emitting layers (27, 28, 29) are calculated using the above-described equations (1) and (2) and (11) using the film thicknesses a and c set above. ) To (17) can be obtained by numerical calculation.

The film thicknesses d _{4 to} d ₁₁ obtained by the numerical calculation are, for example, d ₄ = 40 nm, d ₅ = 25 nm, d ₆ = 10 nm, d ₇ = 21 nm, d ₈ = 40 nm, d ₉ = 25 nm, d ₁₀ = 10 nm, d ₁₁ = 73 nm.

  The element characteristics of the organic light emitting device 30 having the respective film thicknesses set as described above and having the organic light emitting layers (27, 28, 29) using the materials described later were examined.

As a result, luminance = 3000 [d / m ² ], power efficiency = 12 [lm / W], and current efficiency = 49 [cd / A] were obtained. On the other hand, in the conventional optical path calculation method, that is, as described above, in the method that also considers the light (L4, L5, L6) reflected by the anode 51 of the transparent electrode, the luminance = 3000 [d / m ² ]. The power efficiency was 9 [lm / W] and the current efficiency was 39 [cd / A].

  As a result, the organic light emitting device 30 having the film thickness set by the optical path calculation method according to the present embodiment is more efficient than the organic light emitting device having the film thickness set by the conventional optical path calculation method. It became clear that the efficiency showed a good result.

  In the present embodiment, since the organic light emitting device 30 is configured to extract light from the substrate 1 side, the substrate 1 is a transparent substrate that transmits light. An example of the material of the substrate 1 is glass. The thickness is preferably about 50 to 500 μm, for example.

  As with the substrate 1, the anode layer 2 can transmit light and has a thickness of, for example, a transparent electrode of ITO (indium-tin oxide) having a thickness of about 140 to 160 nm. As shown in FIG. 1, an anode terminal 20 obtained by extending the anode layer 2 is connected to the anode layer 2.

  As described above, the organic light emitting layer (27, 28, 29) is formed from the positive electrode transport layer (6, 9, 12), the light emitting part (7, 10, 13) and the electron transport layer (8) from the anode layer 2 side. , 11, 14) are sequentially laminated. In each of the light emitting units (7, 10, 13), for example, as described above, the light emitting unit 7 emits blue light, the light emitting unit 10 emits green light, and the light emitting unit 13 emits red light. The combination of each light emitting portion (7, 10, 13) and the light emission color is not limited to this, and other combinations such as three colors of cyan, magenta, and yellow may be used.

  The organic light emitting layer (27, 28, 29) is a layer other than the hole transport layer (6, 9, 12) and the electron transport layer (8, 11, 14), for example, a hole injection layer, an electron injection layer. Etc. may be used.

  The hole transport layer (6, 9, 12) is for smoothly transporting holes injected from the anode layer 2 or the charge generation layer (15, 16) to the organic light emitting layer (27, 28, 29). The thickness is made of, for example, about 20 to 80 nm of NPB (N, N-di (naphthalyl) -N, N-diphenyl-benzidene).

The electron transport layer (8, 11, 14) is for smoothly transporting electrons injected from the cathode layer 3 or the charge generation layer (15, 16) to the light emitting section (7, 10, 13). The thickness is made of Alq ₃ (aluminum quinolinol complex) having a thickness of about 20 to 30 nm, for example.

  The light emitting section (7, 10, 13) is for emitting light by recombination of injected holes and electrons.

The light-emitting portion 7 has a thickness in which a blue light-emitting species, for example, DPVBi (4,4′-bis (2,2′-diphenylvinyl) -1,1′-biphenyl) is doped by, for example, about 1%. Is made of, for example, Alq _{3 of} about 30 to 50 nm.

The light emitting unit 10 is made of Alq ₃ having a thickness of, for example, about 30 to 50 nm doped with, for example, about 1% of a green light emitting species, for example, dimethylquinacridone.

The light emitting unit 13 is made of Alq ₃ having a thickness of, for example, about 30 to 50 nm doped with, for example, about 1% of a red light emitting species, for example, Nile red.

  The charge generation layers (15, 16) inject holes into the light emitting portions (10, 13) disposed on the cathode layer 3 side of the charge generation layers (15, 16) when a voltage is applied. This is to play a role of injecting electrons into the light emitting portions (7, 10) disposed on the anode layer 2 side of the generation layers (15, 16). The thickness is, for example, about 5 to 20 nm.

Examples of the material of the charge generation layer (15, 16) include vanadium oxide (V ₂ O ₅ ), InZnO (indium zinc oxide), or a mixed layer of these oxides and organic substances.

  The cathode layer 3 has a thickness of about 150 nm, for example, and is made of aluminum.

The insulating layer 4 is for insulating the anode layer 2 and the cathode layer 3 and has a thickness of, for example, about 100 to 200 nm. Examples of the material include SiO ₂ , SiON, SiN, AlN, AlON, Zr ₂ O ₃ , Al ₂ O _{3 and the} like.

  The sealing plate 17 protects and seals the anode layer 2, the cathode layer 3, and the light emitting part (7, 10, 13), and has a thickness of about 50 to 500 μm, for example.

  Examples of the material of the sealing plate 17 include resin, glass, and the like, and metals such as stainless steel (SUS) and copper.

  The seal members (18, 19) are for bonding and sealing the substrate 1 and the sealing plate 17, and use UV curable resin, epoxy resin, or the like.

  The internal space between the sealing plate 17 and the substrate 1 may be filled with an inert gas and a desiccant or the like for absorbing moisture.

(Operating principle)
The operation principle of the organic light emitting device according to the present embodiment is as follows.

  First, a constant voltage is applied between the anode layer 2 and the cathode layer 3 from the external electrode (illustrated) via the anode terminal 20 and the cathode terminal 21 of the organic light emitting device 30. Thus, the light emitting portions (7, 10, and 4) that emit light of each color of blue, green, and red from the anode layer 2 or the charge generation layer (15, 16) through the hole transport layer (6, 9, 12). 13) Holes are injected into the light emitting portion (7, 10, 13) from the cathode layer 3 or the charge generation layer (15, 16) through the electron transport layer (8, 11, 14). Is done. Then, the holes and electrons injected into the light emitting part (7, 10, 13) recombine to emit light of each color. These lights overlap and are emitted to the outside through the substrate 1 to obtain white light.

(Production method)
The method for manufacturing an organic light emitting device according to the first embodiment of the present invention includes a plurality of organic light emitting layers between an anode layer 2 and a cathode layer 3 formed on a substrate 1 as shown in FIGS. Each film thickness of the organic light emitting layer (27, 28, 29) of the organic light emitting device 30 having a configuration in which (27, 28, 29) is laminated is changed from the light emitting position of the organic light emitting layer 27 in contact with the anode layer 2 to the anode layer. The film thickness up to 2 and the film thickness from the light emitting position of the organic light emitting layer 29 in contact with the cathode layer 3 to the cathode layer 3 are set to a predetermined film thickness, and from the light emitting position of each light emitting part (7, 10) to the cathode layer 3 The step of setting the optical distance to be an odd multiple of one-fourth of the emission wavelength of each light emitting section (7, 10), and forming the anode layer 2 on the substrate 1, and the organic light emission by the set film thickness A step of forming a plurality of layers (27, 28, 29) via the charge generation layers (15, 16), and an insulating layer 4 After the film formation, the step of forming the cathode layer 3 and the sealing plate 17 are bonded and sealed to the substrate 1 through the sealing members (18, 19) so that the anode terminal 20 and the cathode terminal 21 are exposed. Process.

  Below, a manufacturing process is explained in full detail.

(A) First, as shown in FIGS. 1 and 2, the thickness of the organic light-emitting device 30 in which three organic light-emitting layers (27, 28, 29) are stacked via charge generation layers (15, 16) is as follows. After setting a and c by the above-described method, the first light emitting section 7 and the second green light emitting section 10 emit light with the respective film thicknesses of the organic light emitting layers (27, 28, 29). For the light (L1, L2) reflected by the cathode layer 3, the optical path is calculated in the same manner as described above using the equations (1) and (2) and equations (11) to (17). To set.

(B) Next, as shown in FIG. 5 (a), the anode layer 2, the hole injection layer 5, and the hole transport layer are formed on the substrate 1 at a set film thickness by a vacuum deposition method or a sputtering method. 6. A light emitting portion 7 that emits monochromatic light, an electron transport layer 8, and a charge generation layer 15 are sequentially formed.

(C) Next, as shown in FIG. 5B, the hole transport layer 9 emits monochromatic light with a set film thickness on the charge generation layer 15 by a vacuum deposition method or a sputtering method. The part 10, the electron transport layer 11, and the charge generation layer 16 are sequentially formed. Next, the hole transport layer 12, the light emitting portion 13 that emits monochromatic light, and the electron transport layer 14 are sequentially formed with the set film thickness.

(D) Next, as shown in FIG. 5C, after the insulating layer 4 is formed, the cathode layer 3 is formed. When the anode layer 2 and the cathode layer 3 are formed, the anode terminal 20 obtained by extending the anode layer 2 is formed, and the cathode terminal 21 obtained by extending the cathode layer 3 is formed.

(E) Finally, as shown in FIG. 6 (d), the sealing plate 17 is bonded and sealed to the substrate 1 through the sealing members (18, 19) so that the anode terminal 20 and the cathode terminal 21 are exposed. The organic light emitting device 30 shown in FIG. 1 is completed.

  Such an organic light emitting device 30 has a conventional interference design, and the light emitted from the light emitting portions (55, 59, 63) is reflected by the light path (L1, L2, L3) reflected by the cathode layer 3 and the anode 51. While calculating the optical path of the reflected light (L4, L5, L6), it is not necessary to calculate the optical path of the light (L4, L5, L6) reflected by the anode 51, thus simplifying the interference design. Can be Thus, even when the number of organic light emitting layers (27, 28, 29) is increased, the film thickness can be set efficiently.

  Further, since the film thicknesses a and c on the side in contact with the anode layer 2 and the cathode layer 3 are set based on the single element characteristics of each organic light emitting layer (27, 28, 29), the plurality of organic light emitting layers ( 27, 28, 29) The MPE type organic light emitting device 30 composed of 27, 28, 29) exhibits good element characteristics and can further simplify the optical interference calculation.

  According to the organic light emitting device and the method for manufacturing the organic light emitting device according to the present embodiment, the light extraction efficiency can be increased by having the film thickness set by the simplified optical interference design.

[Other embodiments]
As described above, the present invention has been described in detail according to the above-described first embodiment. However, for those skilled in the art, the present invention is not limited to the first embodiment described in this specification. Is clear. The present invention can be implemented as modifications and changes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention. Hereinafter, a modified embodiment in which the first embodiment described above is partially modified will be described.

  For example, it is possible to change the thickness of the substrate 1, the sealing plate 17 or the cathode layer 2, and the material constituting the organic light emitting layer (27, 28, 29).

1 is a schematic cross-sectional structure diagram of an organic light-emitting device according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional structure diagram showing a relationship between a film thickness and a refractive index corresponding to each layer in FIG. 1. The block diagram for investigating the element characteristic of the organic light emitting layer in a single state. A diagram showing the device characteristics of the organic light emitting layer in a single state, (a) Voltage [V] - current density [mA / cm ^2] characteristic diagram, (b) Voltage [V] - luminance [cd / ^{m 2} ] Characteristic diagram, (c) current density [mA / cm ² ] −current efficiency [cd / A] characteristic diagram, and (d) luminance [cd / m ² ] −power efficiency [lm / W] characteristic diagram. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the manufacturing method of the organic light-emitting device concerning the 1st Embodiment of this invention, Comprising: (a) After forming the anode layer 2 on the board | substrate 1, the organic light-emitting layer 27 and the charge generation layer 15 are sequentially formed. Steps for forming, (b) Steps for forming organic light emitting layers (28, 29) sequentially via charge generation layer 16, (c) Steps for forming cathode layer 3 after forming insulating layer 4 . It is explanatory drawing of the manufacturing method of the organic light-emitting device which concerns on the 1st Embodiment of this invention, Comprising: (d) The anode terminal 20 and the cathode terminal 21 are put on the sealing board 17 via the sealing member (18, 19). FIG. 6 is a process diagram for bonding and sealing to the substrate 1 so as to expose the substrate. The typical cross-section figure which shows the laminated structure of the conventional organic light-emitting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Anode layer 3 ... Cathode layer 4 ... Insulating layer 5 ... Hole injection layer 6, 9, 12 ... Hole transport layer 7, 10, 13, ... Light emitting portions 8, 11, 14 ... electron transport layers 15, 16 ... charge generation layer 17 ... sealing plates 18, 19 ... sealing member 20 ... anode terminal 21 ... cathode terminal 27, 28, 29 ... organic light emitting layer 30 ... organic light emitting device

Claims (6)

A light transmissive substrate;
A light transmissive anode layer disposed on the substrate;
A plurality of organic light-emitting layers arranged on the anode layer in a stacked manner, at least a hole transport layer, a light-emitting portion, and an electron transport layer from the anode layer side;
A charge generation layer disposed between the organic light emitting layers;
A cathode layer disposed on the organic light emitting layer disposed at the uppermost portion in the stacking direction, and the thickness of each layer sandwiched between the anode layer and the cathode layer is the organic light emitting layer in contact with the anode layer The film thickness from the light emitting position of the layer to the anode layer and the film thickness from the light emitting position of the organic light emitting layer in contact with the cathode layer to the cathode layer are set to predetermined thicknesses, and the light emitting position of each light emitting portion to the cathode An organic light-emitting device, wherein an optical distance to the layer is set to be an odd multiple of one-fourth of a light emission wavelength of each light-emitting portion. The thickness of each layer sandwiched between the anode layer and the cathode layer is expressed by the following formulas (1) to (5):
_{s 1 = (2i-1)} λ 1/4 ··· (1)
_{s 2 = (2l-1)} λ 2/4 ··· (2)
...
s _k = (2m−1) λ _k / 4 (3)
...
s _J-1 = (2n-1) λ _J-1 / 4 (4)
h = a + b ₁ + b ₂ +... + b _k +... b _J−1 + c (5)
However, supposing that the position of the organic light emitting layer is counted from the anode layer side in the stacking order, s _k : from the light emission position of the kth organic light emitting layer at the peak wavelength of the light emitted from the kth organic light emitting layer Optical distance to the cathode layer, λ _k : peak wavelength of light emitted from the kth organic light emitting layer, h: film thickness from the surface of the anode layer in contact with the substrate to the cathode layer, a: first A predetermined film thickness from the light emitting position of the th organic light emitting layer to the surface of the anode layer in contact with the substrate, b _k : light emission of the (k + 1) th organic light emitting layer from the light emitting position of the k th organic light emitting layer Film thickness to position, c: predetermined film thickness from the light emission position of the Jth organic light emitting layer to the cathode layer, k: integer of 1 to J, J: total number of organic light emitting layers, i, l , M, n: an integer greater than or equal to 1
The organic light-emitting device according to claim 1, wherein:   The predetermined film thicknesses a and c are film thicknesses obtained by adjusting the first and Jth organic light emitting layers in a single state to maximize power efficiency [lm / W]. The organic light-emitting device according to claim 2. Each film thickness of the organic light emitting layer of the organic light emitting device having a configuration in which a plurality of organic light emitting layers are laminated between the anode layer and the cathode layer formed on the substrate, and the light emitting position of the organic light emitting layer in contact with the anode layer And a film thickness from the light emitting position of the organic light emitting layer in contact with the cathode layer to the cathode layer is set to a predetermined film thickness, and an optical from the light emitting position of each light emitting portion to the cathode layer Setting the distance to be an odd multiple of one quarter of the emission wavelength of each light emitting section;
Forming the anode layer on the substrate, and forming a plurality of the organic light emitting layers with the set film thickness through a charge generation layer;
After forming the insulating layer, forming the cathode layer;
And a step of bonding and sealing the sealing plate to the substrate through the sealing member so as to expose the anode terminal and the cathode terminal. Each film thickness of the organic light emitting layer has the following formulas (6) to (10):
_{s 1 = (2i-1)} λ 1/4 ··· (6)
_{s 2 = (2l-1)} λ 2/4 ··· (7)
...
s _k = (2m−1) λ _k / 4 (8)
...
s _J-1 = (2n-1) λ _J-1 / 4 (9)
h = a + b ₁ + b ₂ +... + b _k +... b _J−1 + c (10)
However, supposing that the position of the organic light emitting layer is counted from the anode layer side in the stacking order, s _k : from the light emission position of the kth organic light emitting layer at the peak wavelength of the light emitted from the kth organic light emitting layer Optical distance to the cathode layer, λ _k : peak wavelength of light emitted from the kth organic light emitting layer, h: film thickness from the surface of the anode layer in contact with the substrate to the cathode layer, a: first A predetermined film thickness from the light emitting position of the th organic light emitting layer to the surface of the anode layer in contact with the substrate, b _k : light emission of the (k + 1) th organic light emitting layer from the light emitting position of the k th organic light emitting layer Film thickness to position, c: predetermined film thickness from the light emission position of the Jth organic light emitting layer to the cathode layer, k: integer of 1 to J, J: total number of organic light emitting layers, i, l , M, n: an integer greater than or equal to 1
The method for manufacturing an organic light emitting device according to claim 4, wherein:   The predetermined film thicknesses a and c are film thicknesses obtained by adjusting the first and Jth organic light emitting layers in a single state to maximize power efficiency [lm / W]. The method for manufacturing an organic light-emitting device according to claim 5.

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