KR20200118399A - White organic light emitting device - Google Patents

Abstract

An objective of the present invention is to provide a white organic light emitting device capable of improving device life. According to an embodiment of the present invention, the white organic light emitting device comprises a first light emitting unit between a first electrode and a second electrode, and a second light emitting unit over the first light emitting unit. At least one of the first light emitting unit and the second light emitting unit includes a light emitting region control layer. According to another embodiment of the present invention, the white organic light emitting device comprises a first light emitting unit between a first electrode and a second electrode, a second light emitting unit over the first light emitting unit, and a third light emitting unit over the second light emitting unit. At least one among the first light emitting unit, the second light emitting unit, and the third light emitting unit includes a light emitting region control layer.

Description

White organic light emitting device {WHITE ORGANIC LIGHT EMITTING DEVICE}

The present invention relates to an organic light-emitting device, and more particularly, to a white organic light-emitting device capable of improving the device life.

As the information age enters, the field of display that visually expresses electrical information signals has rapidly developed, and in response to this, various flat display devices with excellent performance of thinner, lighter, and low power consumption. Device) is being developed.

Specific examples of such a flat panel display include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an organic light emitting display device. (Organic Light Emitting Device: OLED) and the like.

In particular, as an organic light emitting device, as a self-luminous device, a response speed is fast and luminous efficiency, luminance, and viewing angle are greater than other flat panel displays.

In the organic light-emitting display device, an organic emission layer is formed between two electrodes. Electrons and holes are respectively injected from the two electrodes into the organic emission layer to generate excitons according to the combination of electrons and holes. In addition, it is a device using the principle that light is generated when the generated excitons fall from an excited state to a ground state.

A conventional organic light emitting display device includes a blue light emitting layer made of a blue fluorescent material to implement white color. However, a light emitting layer made of a fluorescent material has a theoretical quantum efficiency of about 25% compared to a light emitting layer made of a phosphorescent material. For this reason, there is a problem that the blue light emitting layer made of a fluorescent material does not produce sufficient luminance compared to the phosphorescent material.

White organic light emitting device (Patent Application No. 10-2007-0053472)

Conventional organic light-emitting devices have limitations in light-emitting characteristics and lifespan performance due to the material and device structure of the organic light-emitting layer, and thus various methods for improving the lifespan in white organic light-emitting devices have been proposed.

As one method, there is a method of using a light emitting layer as a single layer. In this method, a white organic light-emitting device can be manufactured by using a single material or by doping two or more materials. For example, there is a method in which red and green dopants are used for a blue host or red, green, and blue dopants are added to a host material having a large band gap energy. However, this method has a problem in that energy transfer to the dopant is incomplete and it is difficult to adjust the white balance.

In addition, due to the characteristics of the dopant itself, there is a limit to the component of the dopant included in the light emitting layer. In addition, since the focus is on the realization of white light when each emission layer is mixed, the wavelength characteristics having an emitting peak value at a wavelength other than red, green, and blue are displayed. do. Therefore, when the color filter is included, there is a problem that the color reproduction rate is deteriorated. In addition, the lifespan of the dopant material is different, so that a color shift occurs during continuous use.

Alternatively, two light emitting layers having a complementary color relationship may be stacked to emit white light. However, in this structure, when white light passes through the color filter, there is a difference between the peak wavelength region of each light-emitting layer and the transmission region of the color filter. Accordingly, a color range that can be expressed is narrowed, and thus, there may be difficulties in implementing a desired color reproduction rate.

For example, when a blue emission layer and a yellow emission layer are stacked, white light is emitted while peak wavelengths are formed in the blue and yellow wavelength regions. When the white light passes through the red, green, and blue color filters, respectively, the transmittance of the blue wavelength region decreases compared to the red or green wavelength region, resulting in lower luminous efficiency and color reproduction.

In addition, the luminous efficiency of the yellow phosphorescent light emitting layer is relatively higher than that of the blue fluorescent light emitting layer, thereby reducing the panel efficiency and color reproducibility due to the difference in efficiency between the phosphorescent light emitting layer and the fluorescent light emitting layer. In addition, there is a problem that the luminance of blue is relatively lower than that of yellow.

In addition to this structure, in the case of a structure in which a blue fluorescent emission layer and a green-red phosphorescent emission layer are stacked, there is a problem in that the luminance of blue is relatively lower than that of green-red.

As mentioned above, various methods have been proposed to improve the lifetime of the device. However, a structure in which the number of light-emitting units constituting the light-emitting layers is increased has a problem in that a driving voltage increases because a manufacturing cost increases due to an increase in a process and a thickness of a device increases.

Accordingly, the inventors of the present invention recognized the above-mentioned problems, and conducted several experiments to improve the device lifespan by configuring two or more light-emitting layers within one light-emitting unit without increasing the number of light-emitting units constituting the light-emitting layers. .

Accordingly, the inventors of the present invention invented a white organic light-emitting device having a new structure capable of improving device life by configuring two or more light-emitting layers in one light-emitting unit through several experiments.

The problem to be solved according to an embodiment of the present invention is to configure two or more light-emitting layers within one light-emitting unit and further configure a light-emitting area control layer capable of evenly distributing the light-emitting area, thereby improving device lifespan. It is to provide a light emitting device.

The white organic light-emitting device according to an embodiment of the present invention includes a first light-emitting part between a first electrode and a second electrode, and a second light-emitting part on the first light-emitting part. According to an embodiment of the present invention, at least one of the first light emitting unit and the second light emitting unit includes a light emitting area control layer, thereby providing a white organic light emitting device capable of improving a device lifetime.

The white organic light emitting device according to another embodiment of the present invention includes a first light emitting part between the first electrode and the second electrode, a second light emitting part on the first light emitting part, and a third light emitting part on the second light emitting part. Is composed. At least one of the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit includes a light-emitting area control layer, thereby providing a white organic light-emitting device capable of improving a device life.

Details of other embodiments are included in the detailed description and drawings.

By configuring a light emitting region control layer capable of evenly distributing the light emitting regions of the light emitting unit according to an embodiment of the present invention, there is an effect of improving the life of the device.

In addition, there is an effect of preventing deterioration of the light emitting layer and improving the reliability of the device.

The effects of the present invention are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

Since the contents of the invention described in the problems to be solved above, the means for solving the problems, and the effects do not specify essential features of the claims, the scope of the claims is not limited by the matters described in the contents of the invention.

1 is a view showing a white organic light emitting device according to an embodiment of the present invention.
2 is a diagram illustrating an energy band diagram of a light emitting unit according to an embodiment of the present invention.
3 is a view showing a white organic light emitting device according to another embodiment of the present invention.
4 is a diagram illustrating an energy band diagram of a light emitting unit according to another exemplary embodiment of the present invention.
5A is a view showing the light emission intensity of the light emitting unit according to another embodiment of the present invention, and FIG. 5B is a view showing a light emitting area of the light emitting unit according to another embodiment of the present invention.
6 is a view showing a white organic light emitting device according to another embodiment of the present invention.
7 is a view showing a white organic light emitting device according to another embodiment of the present invention.
8 is a diagram illustrating emission intensity of a white organic light emitting diode according to a comparative example and an exemplary embodiment of the present invention.
9 is a view showing a white organic light emitting device according to another embodiment of the present invention.
10 is a view showing a white organic light emitting device according to another embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and the present invention is not limited to the illustrated matters. The same reference numerals refer to the same components throughout the specification. In addition, in describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When'include','have','consists of' and the like mentioned in the present specification are used, other parts may be added unless'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of two parts is described as'upper','upper of','lower of','next to','right' Or, unless'direct' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, when a temporal predecessor relationship is described as'after','following','after','before', etc.,'right' or'direct' It may also include cases that are not continuous unless this is used.

First, second, etc. are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments can be implemented independently of each other or can be implemented together in a related relationship. May be.

Hereinafter, an exemplary embodiment of the present invention will be described in detail through the accompanying drawings and exemplary embodiments.

1 is a view showing a white organic light emitting device according to an embodiment of the present invention.

The white organic light emitting device 100 illustrated in FIG. 1 includes a first light emitting unit 110 and a second light emitting unit between the first electrode 102 and the second electrode 104, and the first and second electrodes 102 and 104. It has a part 120.

The first electrode 102 is an anode supplying holes and may be formed of transparent conductive materials such as TCO (Transparent Conductive Oxide), such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), etc. It is not limited.

The second electrode 104 is a cathode that supplies electrons and is formed of metallic materials such as gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), magnesium (Mg), or the like. It may be formed of an alloy, but is not necessarily limited thereto.

Each of the first electrode 102 and the second electrode 104 may be referred to as an anode or a cathode.

The first electrode 102 may be a transmissive electrode, and the second electrode 104 may be a reflective electrode. In addition, the first electrode 102 may be a reflective electrode, and the second electrode 104 may be configured as a transflective electrode.

The first light emitting part 110 includes a first hole transporting layer (HTL) 112, a first emitting layer (EML) 114, and a first electron transporting layer (HTL) on the first electrode 102. ETL; Electron Transporting Layer (ETL) 116 may be included.

Although not shown in the drawing, a hole injecting layer (HIL) may be additionally configured. The hole injection layer HIL is formed on the first electrode 102 and serves to smoothly inject holes from the first electrode 102. The first hole transport layer (HTL) 112 supplies holes from the hole injection layer HIL to the first emission layer (EML) 114. The first electron transport layer (ETL) 116 supplies electrons from the second electrode 104 to the first emission layer (EML) 114.

The hole injection layer (HIL) is MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), CuPc (copper phthalocyanine), or PEDOT/PSS (poly(3,4-ethylenedioxythiphene, polystyrene sulfonate)). Although it may be made, it is not necessarily limited thereto.

Light is generated in the first emission layer (EML) 114 because holes supplied through the hole transport layer HIL and electrons supplied through the electron transport layer (ETL) 116 are recombined.

The first hole transport layer (HTL) 112 may be made of the same material as the second hole transport layer (HTL) 122, but is not limited thereto.

The first hole transport layer (HTL) 112 may be formed by applying two or more layers or two or more materials.

The first electron transport layer (ETL) 116 may be formed of the same material as the second electron transport layer (ETL) 126, but is not limited thereto.

The first electron transport layer (ETL) 116 may be formed by applying two or more layers or two or more materials.

The first emission layer (EML) 114 is composed of a blue emission layer or a red-blue emission layer. The peak wavelength of the emission region of the blue emission layer may be in the range of 440 nm to 480 nm. The peak wavelength of the emission region of the red-blue emission layer may range from 600 nm to 650 nm.

A first charge generating layer (CGL) 140 may be further formed between the first light-emitting part 110 and the second light-emitting part 120. The first charge generation layer (CGL) 140 adjusts a balance of charges between the first and second light emitting units 110 and 120. The charge generation layer 140 may include an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL).

The N-type charge generation layer (N-CGL) may be formed of an organic layer doped with an alkali metal such as Li, Na, K, or Cs, or an alkaline earth metal such as Mg, Sr, Ba, or Ra, respectively. It is not limited.

Each of the P-type charge generation layers P-CGL may be formed of an organic layer including a P-type dopant, but is not limited thereto. In addition, the first charge generation layer (CGL) 140 may be formed as a single layer.

The second light emitting part 120 includes a second hole transporting layer (HTL) 122, a second emitting layer (EML) 124, and a second electron transporting layer (ETL) 126 ) Can be included. Although not shown in the drawing, an electron injection layer (EIL) may be additionally formed on the second electron transport layer (ETL) 126. In addition, a hole injection layer (HIL) may be additionally formed.

The second hole transport layer (HTL) 122 may be made of the same material as the first hole transport layer (HTL) 112, but is not limited thereto.

The second hole transport layer (HTL) 122 may be formed by applying two or more layers or two or more materials.

The second electron transport layer (ETL) 126 may be formed of the same material as the first electron transport layer (ETL) 116, but is not limited thereto.

The second electron transport layer (ETL) 126 may be formed by applying two or more layers or two or more materials.

The first emission layer (EML) 124 of the second emission part 120 is formed of a yellow-green emission layer. The peak wavelength of the emission region of the yellow-green emission layer may be in the range of 510 nm to 580 nm.

In this structure, the first emission layer (EML) 124 of the second emission unit 120 is a yellow-green emission layer and must emit light in both green and red regions. (Red) The luminous efficiency of the light-emitting layer is lower than that of green. Accordingly, in order to improve the luminous efficiency of the red emission layer, a red emission layer is further formed with the second emission layer (EML) 125.

2 is a diagram illustrating an energy band diagram of a light emitting unit according to an embodiment of the present invention.

That is, when two light-emitting layers are formed in the second light-emitting part 120, an energy band diagram is shown.

The second light-emitting unit 120 includes two light-emitting layers, a yellow-green light-emitting layer and a second light-emitting layer EML, which are the first light-emitting layer EML 124 of the second light-emitting unit 120 125) is composed of a red light emitting layer.

In this configuration, the peak wavelength of the emission region of the red emission layer is in the range of 600 nm to 650 nm, and the peak wavelength of the emission region of the yellow-green emission layer is It ranges from 510 nm to 580 nm. Since the light emitting regions of the red light emitting layer and the yellow-green light emitting layer are close, the light emitting regions of the red and yellow-green light emitting layers are aggregated. As a result, the light emitting area is skewed toward one of the red or yellow-green light emitting layers. Accordingly, deterioration in the second light-emitting unit 120 is accelerated, and the life of the device is reduced. In addition, there is a problem that a desired color cannot be realized at a peak wavelength of a desired emission region.

In order to solve the above problems, the inventors of the present invention can improve the agglomeration of the light-emitting area that occurs in a structure including at least two or more light-emitting layers in one light-emitting unit, maximize the light-emitting area, and distribute the light-emitting area evenly. I invented a structure that was there.

That is, by configuring at least two light-emitting layers in one light-emitting unit and further configuring a light-emitting area control layer capable of evenly distributing the light-emitting areas, a structure capable of improving device life has been invented.

3 is a view showing a white organic light emitting device according to another embodiment of the present invention.

In describing the present embodiment, descriptions of components that are the same as or corresponding to the previous embodiment will be omitted.

The white organic light-emitting device 200 of FIG. 3 includes a first electrode 102 and a second electrode 104, and a first light-emitting unit 110 and a second light-emitting unit between the first and second electrodes 102 and 104. It has 120.

Two emission layers and an emission area control layer (EACL) 190 are formed on the second emission part 120. The second The first emission layer (EML) 124 of the emission unit 120 is formed of a yellow-green emission layer, and the second emission layer (EML) 125 is formed of a red emission layer. In addition, a yellow-green emission layer is formed as the emission area control layer (EACL) 190.

The peak wavelength of the emission region of the yellow-green emission layer, which is the first emission layer (EML) 124 of the second emission unit 120, may range from 510 nm to 580 nm. . The peak wavelength of the emission region of the red emission layer, which is the second emission layer (EML) 125, may range from 600 nm to 650 nm.

The peak wavelength of the emission region of the yellow-green emission layer of the emission region control layer (EACL) 190 may be in the range of 510 nm to 580 nm.

In addition, the white organic light-emitting device according to another embodiment of the present invention may be applied to a bottom emission method, a top emission method, or a good emission method.

4 is a diagram illustrating an energy band diagram of a light emitting unit according to another exemplary embodiment of the present invention.

In the drawing, the first emission layer (EML) 124 and the second emission layer (EML) 125 of the second emission part 120 are illustrated as one dopant and one host. However, holes are formed in one dopant. ) It may be composed of two hosts composed of a host and an electron host. When two hosts are used in one dopant, the efficiency and lifetime of the light emitting layer may be improved, but the present invention is not limited thereto.

Further, in the drawing, the emission area control layer (EACL) 190 is illustrated as one dopant and one host, but may be composed of two hosts composed of a hole host and an electron host in one dopant. have. When two hosts are used in one dopant, the efficiency and lifetime of the light emitting layer may be improved, but the present invention is not limited thereto.

When two hosts are formed in one dopant, the first emission layer (EML) 124 and the emission region control layer (EACL) 190 of the second emission unit 120 will be described. Holes move from the hole host of the first emission layer (EML) 124 to the hole host of the emission region control layer (EACL) 190. Electrons move from the electronic host of the first emission layer (EML) 124 to the electron host of the emission area control layer (EACL) 190, and become excitons in which the moved holes and electrons are combined, and the light emitting unit Light is generated within.

A dopant constituting a yellow-green emission layer that is the first emission layer (EML) 124 and a dopant constituting a yellow-green emission layer that is the emission region control layer (EACL) 190 Can be configured in the same way. And the host constituting the yellow-green emission layer, which is the first emission layer (EML) 124, is a host constituting the yellow-green emission layer, which is the emission area control layer (EACL) 190 Can be configured differently. However, it is not necessarily limited thereto. In addition to one, the host may be composed of two hosts, a hole host and a charge host. It is preferable that the hole mobility of the host included in the emission area control layer (EACL) 190 is faster than that of the host of the first emission layer (EML) 124. For example, the hole mobility of the emission area control layer (EACL) 190 is preferably faster than 1×10 -5 cm 2 /Vs. This makes the generation of excitons of the emission region control layer (EACL) 190 faster than excitons generated in the first emission layer (EML) 124, and thus the first emission layer (EML) 124 The excitons of may be moved away from the second emission layer (EML) 125.

As shown in FIG. 4, the density of excitons generated in the first emission layer (EML) 124 and the second emission layer (EML) 125 is reduced by the emission area control layer (EACL) 190 It is to let. For this reason, the distribution of excitons of the first emission layer (EML) 124 is moved away from the second emission layer (EML) 125 by the emission region control layer (EACL) 190. Therefore, by disengaging the emission area of the first emission layer (EML) 124 and the second emission layer (EML) 125 to improve the aggregation of the emission area, deterioration in the second emission part 120 It's slowing down.

Accordingly, since the light-emitting regions are evenly distributed in the second light-emitting part 120, the deterioration phenomenon in the second light-emitting part 120 can be reduced, and the lifetime of the device can be improved by inducing an increase in life.

5A is a view showing the light emission intensity of the light emitting unit according to another embodiment of the present invention, and FIG. 5B is a view showing a light emitting area of the light emitting unit according to another embodiment of the present invention.

That is, FIGS. 5A and 5B are diagrams showing a light emitting area and a light emission intensity of the light emitting part as an experiment result of confirming the light emitting area of the light emitting area control layer in another embodiment of the present invention.

In order to confirm whether the light emitting area control layer (EACL) 190 of the present invention contributes to the improvement of the lifespan, the inventors constructed several devices and repeated various experiments. As a result of repeated experiments, the device of Table 1 was constructed. Through this experiment, it was confirmed that when at least two light-emitting layers are formed in one light-emitting unit, there is no effect on the device characteristics and the lifespan is improved.

Each device for this experiment was composed of 8, and the configuration of the device is shown in Table 1 below.

In this experiment, the device should be composed of the first emission layer (EML) 124, the second emission layer (EML) 125, and the emission region control layer (EACL) 190 of the second emission unit 120. One, as shown in Table 1, except for the second emission layer (EML) 125, an arbitrary emission layer is formed between the first emission layers (EML) 124. The reason is that the energy of the red emission layer, which is the second emission layer (EML) 125, is higher than that of the yellow-green emission layer, which is the first emission layer (EML) 124, This is because it is displayed in red. Therefore, in order to check the emission area and emission intensity of the emission area control layer 190, the configuration of the device is configured as shown in Table 1 above. In addition, the emission region and emission intensity of the red emission layer, which is an optional emission layer, were checked.

In Table 1, elements 1 to 3 are composed of a first light-emitting layer, a light-emitting layer, and a light-emitting region control layer. The first emission layer is expressed as the first emission layer 1 to the first emission layer 4 according to the thickness.

The first emission layer 1 of Device 1 is a yellow-green emission layer and has a thickness of 20 Å, and the emission layer is a red emission layer, which is an optional emission layer, and a thickness of 20 Å. The first emission layer 3 is a yellow-green emission layer, has a thickness of 160 Å, and the thickness of the emission region control layer is 200 Å. The thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention and does not limit the present invention.

The first emission layer 2 of Device 2 is a yellow-green emission layer and has a thickness of 90 Å, and the emission layer is a red emission layer, which is an optional emission layer, and a thickness of 20 Å. The first emission layer 2 is a yellow-green emission layer, has a thickness of 90 Å, and the thickness of the emission region control layer is 200 Å. The thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention and does not limit the present invention.

The first emission layer 3 of Device 3 is a yellow-green emission layer and has a thickness of 160 Å, and the emission layer is a red emission layer, which is an optional emission layer, and a thickness of 20 Å. The first emission layer 1 is a yellow-green emission layer and has a thickness of 20 Å, and the thickness of the emission region control layer is 200 Å. The thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention and does not limit the present invention.

Element 4 is composed of a first light-emitting layer 4, a light-emitting layer, and a light-emitting region control layer. The first emission layer 4 is a yellow-green emission layer and has a thickness of 180 Å, and the emission layer is a red emission layer, which is an optional emission layer, and a thickness of 20 Å. The thickness of the emission region control layer is 200 Å. The thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention and does not limit the present invention.

In Table 1, the elements 5 to 8 are composed of a first light-emitting layer, a light-emitting region control layer, and a light-emitting layer. The emission area control layer is expressed as the emission area control layer 1 to the emission area control layer 4 according to the thickness.

Element 5 is composed of a first light-emitting layer, a light-emitting layer, and a light-emitting region control layer 4. The thickness of the first emission layer is 200 Å, the emission layer is a red emission layer, which is an optional emission layer, and the thickness is 20 Å. The emission area control layer 4 is a yellow-green emission layer and has a thickness of 180 Å. The thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention and does not limit the present invention.

Devices 6 to 8 consist of a first light-emitting layer, a light-emitting region control layer, and a light-emitting layer. The emission area control layer is expressed as the emission area control layer 1 to the emission area control layer 3 according to the thickness.

The thickness of the first emission layer of the device 6 is 200 Å, the emission region control layer 1 is a yellow-green emission layer, and the thickness is 20 Å. The emission layer is a red emission layer, which is an optional emission layer, and has a thickness of 20 Å, and the emission region control layer 3 is a yellow-green emission layer and a thickness of 160 Å. In addition, the thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention, and does not limit the present invention.

The thickness of the first emission layer of the device 7 is 200 Å, the emission region control layer 2 is a yellow-green emission layer, and the thickness is 20 Å. The emission layer is a red emission layer, which is an optional emission layer, and has a thickness of 20 Å, and the emission region control layer 2 is a yellow-green emission layer and a thickness of 90 Å. The thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention and does not limit the present invention.

The thickness of the first emission layer of the device 8 is 200 Å, the emission region control layer 3 is a yellow-green emission layer, and the thickness is 160 Å. The emission layer is a red emission layer, which is an optional emission layer, and has a thickness of 20 Å, and the emission region control layer 1 is a yellow-green emission layer and a thickness of 20 Å. The thickness of the emission layers or the emission region control layer is arbitrarily set for the experiment of the present invention and does not limit the present invention.

As shown in FIG. 5A, the emission intensity is shown when the emission region control layer of the present invention is applied. As a result of checking the emission intensity of the red emission layer, it can be seen that the emission intensity of the devices 1 to 6 increases at 600 nm to 650 nm, which is the peak wavelength of the emission region of the red emission layer.

That is, in the devices 1 to 6, the emission intensity in the emission peak area of the red emission layer is increased by excitons generated between the emission area control layer 190 and the first emission layer (EML) 124. Will increase. On the other hand, devices 7 and 8 decrease the luminous intensity at 600 nm to 650 nm, which is the peak wavelength of the emission region of the red emission layer, so excitons were not generated in devices 7 and 8. You can see the sound. Accordingly, it can be confirmed that the light emission intensity is increased by applying the light emission region control layer of the present invention.

As shown in FIG. 5B, the emission region of the first emission layer (EML) 124 is a portion indicated by “a”. It can be seen that the emission area of the second emission part 120 is increased from the emission area "a" to the emission area "E" by the emission area control layer 190. This confirms that by evenly distributing the light-emitting area in the light-emitting part, it is possible to reduce the deterioration phenomenon in the light-emitting part and induce an increase in lifespan, thereby improving the life of the device.

According to this experiment, when two light-emitting layers are configured in one light-emitting part, which is an embodiment of the present invention, since the light-emitting areas of the two light-emitting layers are separated, the aggregation of the light-emitting areas between the two light-emitting layers is caused by It can be seen that it is prevented by Accordingly, it can be seen that by spreading the distribution of the light-emitting area evenly, the light-emitting area is increased and the light-emitting intensity is also increased in the desired wavelength area.

Accordingly, since the light-emitting regions are evenly distributed in the second light-emitting part 120, the deterioration phenomenon in the second light-emitting part 120 can be reduced, and the lifetime of the device can be improved by inducing an increase in life.

6 is a view showing a white organic light emitting device according to another embodiment of the present invention. In describing the present embodiment, descriptions of components that are the same as or corresponding to the previous embodiment will be omitted.

The white organic light emitting device 300 according to another embodiment of the present invention includes a first light emitting unit 110 between the first electrode 102 and the second electrode 104, and between the first electrode and the second electrode 102 and 104. A second light emitting unit 120 is provided. The first emission layer (EML) 114 of the first emission unit 110 constitutes a red emission layer, and the second emission layer (EML) 115 of the first emission unit 110 is yellow-green. The (Yellow-Green) light emitting layer is formed. A blue emission layer is formed by the first emission layer (EML) 124 of the second emission unit 120.

In addition, a light emitting area control layer (EACL) 290 is formed on the first light emitting part 110. The emission region control layer 290 is formed of a yellow-green emission layer.

The peak wavelength of the emission region of the red emission layer, which is the first emission layer (EML) 114 of the first emission unit 110, may range from 600 nm to 650 nm. In addition, a peak wavelength of the emission region of the yellow-green emission layer of the second emission layer (EML) 115 may be in the range of 510 nm to 580 nm. The peak wavelength of the emission region of the blue emission layer, which is the first emission layer (EML) 124 of the second emission unit 120, may range from 510 nm to 580 nm.

The peak wavelength of the emission region of the yellow-green emission layer of the emission region control layer (EACL) 290 may be in the range of 510 nm to 580 nm.

The first emission layer (EML) 124 of the second emission part 120 may be formed of a blue emission layer or a red-blue emission layer. The peak wavelength of the emission region of the blue emission layer may be in the range of 440 nm to 480 nm. The peak wavelength of the emission region of the red-blue emission layer may range from 600 nm to 650 nm.

The second emission layer (EML) 115 of the first emission unit 110 and the emission region control layer (EACL) 290 may have the same dopant and different hosts, It is not necessarily limited thereto.

In addition to one, the host may be composed of two hosts, a hole host and a charge host. It is preferable that the hole mobility of the host included in the emission area control layer (EACL) 290 is higher than that of the host of the second emission layer (EML) 115. For example, the hole mobility of the emission area control layer (EACL) 290 is preferably faster than 1×10 -5 cm 2 /Vs. This makes the generation of excitons of the emission area control layer (EACL) 290 faster than excitons generated in the second emission layer (EML) 115, and thus the second emission layer (EML) 115 The excitons of may be moved away from the first emission layer (EML) 114.

The density of excitons generated in the first emission layer (EML) 114 and the second emission layer (EML) 115 is reduced by the emission area control layer (EACL) 290. For this reason, the distribution of excitons of the second emission layer (EML) 115 is moved away from the first emission layer (EML) 114 by the emission region control layer (EACL) 190. Accordingly, the light emission area of the first emission layer (EML) 114 and the second emission layer (EML) 115 are separated to improve the aggregation of the emission area, and deterioration in the first emission unit 110 It's slowing down.

Accordingly, since the light-emitting regions are evenly distributed in the first light-emitting unit 110, it is possible to reduce the deterioration phenomenon in the first light-emitting unit 110 and induce an increase in life time, thereby improving the life of the device.

The white organic light-emitting device according to another embodiment of the present invention may be applied to a bottom emission method, a top emission method, or a good emission method.

7 is a view showing a white organic light emitting device according to another embodiment of the present invention. In describing the present embodiment, descriptions of components that are the same as or corresponding to the previous embodiment will be omitted.

In another embodiment of the present invention, the white organic light emitting device 400 includes a first light emitting unit 110 between the first electrode 102 and the second electrode 104, the first electrode and the second electrode 102, 104, A second light-emitting unit 120 and a third light-emitting unit 130 are provided. The first emission layer (EML) 114 of the first emission unit 110 constitutes a blue emission layer, and the first emission layer (EML) 124 of the second emission unit 120 is yellow-green. The (Yellow-Green) light emitting layer was formed.

A red emission layer is further formed as the second emission layer (EML) 125 of the second emission unit 120 to form at least two emission layers in the second emission unit 120. In addition, a light emitting area control layer (EACL) 390 is formed on the second light emitting part 120. The emission area control layer 390 is formed of a yellow-green emission layer.

The peak wavelength of the emission region of the blue emission layer, which is the first emission layer (EML) 114 of the first emission unit 110, may range from 440 nm to 480 nm.

The peak wavelength of the emission region of the yellow-green emission layer, which is the first emission layer (EML) 124 of the second emission unit 120, may range from 510 nm to 580 nm.

The peak wavelength of the emission region of the red emission layer, which is the second emission layer (EML) 125 of the second emission unit 120, may range from 600 nm to 650 nm.

The peak wavelength of the emission region of the yellow-green emission layer, which is the emission region control layer (EACL) 390, may range from 510 nm to 580 nm.

The blue light emitting layer made of a fluorescent material has a theoretical quantum efficiency of about 25% compared to the light emitting layer made of a phosphorescent material. For this reason, there is a problem that the blue light emitting layer made of a fluorescent material does not produce sufficient luminance compared to other phosphorescent materials. Accordingly, a first emission layer (EML) 134 is further formed on the third emission unit 130 in order to improve the lifespan by improving the luminous efficiency of the blue emission layer.

Accordingly, the white organic light-emitting device 400 according to another embodiment of the present invention constitutes a blue light-emitting layer with the first light-emitting layer (EML) 114 of the first light-emitting unit 110, and the second light-emitting unit The first emission layer (EML) 124 of 120 constitutes a third emission unit 130 from the emission unit including a yellow-green emission layer. The first emission layer 134 constituting the third emission part may be formed of a blue emission layer.

Even in a structure in which the number of light-emitting units is further increased as described above, when the light-emitting region control layer of the present invention is applied, light emission efficiency is maintained and lifespan is improved. This will be described later in FIG. 8 and Table 2.

Although at least two light-emitting layers are formed on the second light-emitting unit 120 as an example, it is possible to configure at least two or more light-emitting layers on the second light-emitting unit 120 according to a configuration or characteristic of a device. In addition, it is also possible to configure at least two or more light-emitting layers on the first light-emitting unit 110 according to the configuration or characteristics of the device. In addition, it is also possible to configure at least two or more light-emitting layers on the third light-emitting unit 130 according to the configuration or characteristics of the device.

The first emission layer (EML) 124 of the second emission unit 120 may be composed of one dopant and one host, and may be composed of two hosts composed of a hole host and an electronic host in one dopant. I can. When two hosts are used in one dopant, the efficiency and lifetime of the light emitting layer may be improved, but the present invention is not limited thereto.

The emission area control layer (EACL) 390 may be composed of one dopant and one host, and may be composed of two hosts composed of a hole host and an electronic host in one dopant. When two hosts are used in one dopant, the efficiency and lifetime of the light emitting layer may be improved, but the present invention is not limited thereto.

A yellow-green emission layer that is the first emission layer (EML) 124 of the second emission unit 120 and a yellow-green emission layer that is the emission area control layer (EACL) 390 The dopant constituting the light emitting layer is the same and the host is configured differently. In addition to one, the host may be composed of two hosts, a hole host and a charge host. It is preferable that the hole mobility of the host included in the emission region control layer 390 is higher than that of the host of the first emission layer (EML) 124. For example, it is preferable that the hole mobility of the emission region control layer 390 is faster than 1×10 -5 cm 2 /Vs. This makes the generation of excitons of the emission region control layer 390 faster than excitons generated in the first emission layer (EML) 124, and thus excitons of the first emission layer (EML) 124 ( Exciton) can be moved away from the second emission layer (EML) 125.

Exciton generated in the first emission layer (EML) 124 and the second emission layer (EML) 125 of the second emission unit 120 by the emission area control layer (EACL) 390 It reduces the density. Accordingly, the distribution of excitons of the first emission layer (EML) 124 is moved away from the second emission layer (EML) 125 by the emission region control layer 390. Therefore, by disengaging the emission area of the first emission layer (EML) 124 and the second emission layer (EML) 125 to improve the aggregation of the emission area, deterioration in the second emission part 120 It's slowing down.

Accordingly, since the light-emitting regions are evenly distributed in the second light-emitting part 120, the deterioration phenomenon in the second light-emitting part 120 can be reduced, and the lifetime of the device can be improved by inducing an increase in life.

The first light-emitting unit 110 and the second light-emitting unit 120 are described for components that are the same as or corresponding to the previous embodiment, and thus will be omitted.

The third light emitting part 130 is a third electron transporting layer (ETL) 136, a first emitting layer (EML) 134, a third hole transporting layer under the second electrode 104 (HTL; Hole Transporting Layer) 132 may be included. Although not shown in the drawing, an electron injection layer (EIL) may be additionally formed on the third electron transport layer (ETL) 136. In addition, a hole injection layer (HIL) may be additionally formed.

The third hole transport layer (HTL) 132 is TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-bi-phenyl-4,4'-diamine) or NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine) may be formed, but is not limited thereto.

The third hole transport layer (HTL) 132 may be configured by applying two or more layers or two or more materials.

The third electron transport layer (ETL) 136 may be made of oxadiazole, triazole, phenanthroline, benzoxazole, benzthiazole, or the like, It is not necessarily limited thereto.

The third electron transport layer (ETL) 136 may be formed by applying two or more layers or two or more materials.

The first emission layer (EML) 134 may include a blue emission layer or a red-blue emission layer. The peak wavelength of the emission region of the blue emission layer may be in the range of 440 nm to 480 nm. The peak wavelength of the emission region of the red-blue emission layer may range from 600 nm to 650 nm.

A second charge generating layer (CGL) 150 may be further formed between the second light-emitting part 120 and the third light-emitting part 130. The second charge generation layer 150 adjusts the balance of charges between the second and third light emitting units 120 and 130. The second charge generation layer (CGL) 150 may include an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL).

The N-type charge generation layer (N-CGL) serves to inject electrons into the second light-emitting unit 120, and the P-type charge generation layer (P-CGL) is used as the third light-emitting unit 130. It serves to inject holes. The present invention is not limited thereto, and the second charge generation layer CGL 150 may be formed as a single layer.

The N-type charge generation layer (N-CGL) may be formed of an organic layer doped with an alkali metal such as Li, Na, K, or Cs, or an alkaline earth metal such as Mg, Sr, Ba, or Ra, respectively. It is not limited.

Each of the P-type charge generation layers P-CGL may be formed of an organic layer including a P-type dopant, but is not limited thereto. The first charge generation layer (CGL) 140 is the same material of the N-type charge generation layer (N-CGL) and the P-type charge generation layer (P-CGL) of the second charge generation layer (CGL) 150 It may be made of, but is not necessarily limited thereto.

In addition, although the white organic light emitting device according to another embodiment of the present invention has been described for a bottom emission method, it may be applied to a top emission method or a good emission method.

8 is a diagram illustrating emission intensity of a white organic light emitting diode according to a comparative example and an exemplary embodiment of the present invention.

As a comparative example, a red emission layer and a yellow-green emission layer are formed as emission layers in the second emission part.

In an embodiment of the present invention, a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit are provided, and at least two light-emitting layers and a light-emitting region control layer are provided in the second light-emitting unit. The first emission layer (EML) 114 of the first emission part is formed of a blue emission layer. The first and second emission layers (EML) 124 and 125 of the second emission part are composed of a yellow-green emission layer and a red emission layer. The emission region control layer is formed of a yellow-green emission layer. The first emission layer (EML) 134 of the third emission part is formed of a blue emission layer.

In FIG. 8, the horizontal axis represents the wavelength region of light, and the vertical axis represents the light emission intensity.

In Examples A and B, different thicknesses of the first emission layer, the second emission layer, and the emission region control layer were applied. In Example A, the sum of the thicknesses of the first emission layer and the emission region control layer and the thickness of the first emission layer of the comparative example are the same. In Example B, the sum of the thicknesses of the first emission layer and the emission region control layer and the thickness of the first emission layer in Comparative Example are thicker.

As shown in FIG. 8, it was found that the luminous intensity of Comparative Examples, Example A and Example B was almost unchanged in the range of 440 nm to 480 nm of the peak wavelength of the emission region of the blue emission layer. I can. It can be seen that this does not affect the lifetime of the light-emitting layer that occurs when two or more light-emitting layers are formed in one light-emitting part, and the light-emitting intensity is maintained.

It can be seen that the peak wavelength of the emission region of the yellow-green emission layer is in the range of 510 nm to 580 nm, and the emission intensity of Example B is increased compared to the comparative example. It can be seen that since the luminous efficiency of the blue light-emitting layer is not lowered and the light-emitting efficiency of the blue light-emitting layer is increased, the device life can be improved. And, comparing Example A and Example B, it can be seen that Example B has an increased light emission intensity than Example A. This seems to be because in Example B, as the thickness of the device increases, excitons in the emission layer move to the electron transport layer, so that the excitons less destroy the hole transport layer.

It can be seen that the peak wavelength of the emission region of the red emission layer is in the range of 600 nm to 650 nm, and the emission intensity of Examples A and B is increased compared to the Comparative Example. It can be seen that since the luminous efficiency of the red light-emitting layer is not lowered and the light-emitting efficiency of the red light-emitting layer is increased, the device life can be improved. In addition, it is possible to solve the problem of lowering the luminous efficiency of the red light-emitting layer that occurs during device configuration.

As described above, it can be seen that when the emission region control layer of the present invention is applied, device characteristics are maintained and device life is improved.

In addition, Table 2 below compares the efficiency, quantum efficiency, and lifetime according to the comparative example and the embodiment of the present invention.

Comparative Example and Examples A and B are the same as those described in FIG. 7. That is, in an exemplary embodiment of the present invention, a first light-emitting part, a second light-emitting part, and a third light-emitting part are provided, and at least two light-emitting layers and a light-emitting region control layer are provided in the second light-emitting part. The first emission layer (EML) 114 of the first emission part is formed of a blue emission layer. The first emission layer (EML) 124 of the second emission part is a yellow-green emission layer and a second emission layer (EML) 125 of red It is composed of a light emitting layer. The first emission layer (EML) 124 is formed of a yellow-green emission layer as the emission area control layer. The first emission layer (EML) 134 of the third emission part is formed of a blue emission layer.

As a comparative example, a red emission layer and a yellow-green emission layer are formed as emission layers in the second emission part.

As shown in Table 2, it can be seen that there is no change in the efficiencies of the light emitting layers in Comparative Examples, Examples A and B. In the case of configuring two light emitting layers in one light emitting part of the present invention, it can be seen that there is no effect in terms of efficiency compared to the comparative example. It can be seen that this does not affect device characteristics that occur when two or more light-emitting layers are formed in one light-emitting unit, and luminous efficiency is maintained.

In addition, in terms of device characteristics, it can be seen that an increase in driving voltage V, which occurs when two or more light-emitting layers are formed in one light-emitting part, does not appear.

EQE (External quantum efficiency) is external quantum efficiency, which refers to the luminous efficiency when light goes out of the organic light emitting device. In addition, compared to the comparative example, it can be seen that there is no change even when the EQE is composed of two or more light-emitting layers in one light-emitting part. That is, it can be seen that there is no effect on the luminous efficiency.

And, compared to the comparative example, it can be seen that the lifetime of the light emitting layers is improved by about 10% to 50%. That is, compared to the comparative example, the lifespan of the red, green, and blue light-emitting layers was improved without any reduction in lifespan when two or more light-emitting layers were formed in one light-emitting part. . Therefore, it can be seen that in the white (White) lifespan is improved by 20% to 40% compared to the comparative example.

In addition, it can be seen that even if one light-emitting part is additionally configured in addition to the two light-emitting parts, when the light-emitting region control layer of the present invention is applied, device characteristics such as luminous efficiency are maintained and device life is improved.

In the present invention, the second light-emitting unit is composed of at least two light-emitting layers. However, in addition to the at least two light-emitting layers, the second light-emitting unit may be composed of two or more light-emitting layers according to the configuration or characteristics of the device. In addition, in addition to the second light-emitting part, the first light-emitting part may be composed of at least two or more light-emitting layers, depending on the configuration or characteristics of the device. In addition, it is also possible to configure the third light-emitting unit with at least two or more light-emitting layers in addition to the second light-emitting unit according to the configuration or characteristics of the device.

9 is a view showing a white organic light emitting device according to another embodiment of the present invention. In describing the present embodiment, descriptions of components that are the same as or corresponding to the previous embodiment will be omitted.

The white organic light emitting device 500 according to another embodiment of the present invention includes a first light emitting unit 110 between the first electrode 102 and the second electrode 104, the first electrode and the second electrode 102, 104, A second light emitting part 120 and a third light emitting part 130 are provided.

The first emission layer (EML) 114 of the first emission unit 110 is composed of a red emission layer, and the second emission layer (EML) 115 is composed of a yellow-green emission layer. .

The first emission layer (EML) 124 of the second emission unit 120 is composed of a blue emission layer, and the first emission layer (EML) 134 of the third emission unit 130 is blue. ) It consists of a light emitting layer.

In addition, the emission area control layer (EACL) 490 is formed on the first light-emitting unit 110, and the emission area control layer (EACL) 490 is formed of a blue emission layer.

The peak wavelength of the emission region of the red emission layer, which is the first emission layer (EML) 114 of the first emission unit 110, may range from 600 nm to 650 nm. The peak wavelength of the emission region of the yellow-green emission layer of the second emission layer (EML) 115 may range from 510 nm to 580 nm.

The peak wavelength of the emission region of the blue emission layer, which is the first emission layer (EML) 124 of the second emission unit 120, may range from 440 nm to 480 nm.

The peak wavelength of the emission region of the blue emission layer, which is the first emission layer (EML) 134 of the third emission unit 130, may range from 440 nm to 480 nm.

The peak wavelength of the emission region of the yellow-green emission layer, which is the emission area control layer (EACL) 490, may range from 510 nm to 580 nm.

The first emission layer (EML) 124 of the second emission unit 110 may be formed of a red-blue emission layer according to the configuration or characteristics of the device. The peak wavelength of the light emitting region of the red-blue light emitting layer may be in the range of 600 nm to 650 nm.

In addition, the first emission layer (EML) 134 of the third emission unit 110 may be formed of a red-blue emission layer according to a configuration or characteristic of a device. The peak wavelength of the light emitting region of the red-blue light emitting layer may be in the range of 600 nm to 650 nm.

The second emission layer (EML) 115 and the emission region control layer (EACL) 490 may have the same dopant and different hosts, but are not limited thereto.

The second emission layer (EML) 115 of the first emission unit 110 and the emission region control layer 490 may have the same dopant and different host configurations, and are limited thereto. It does not become.

In addition to one, the host may be composed of two hosts, a hole host and a charge host. It is preferable that the hole mobility of the host included in the emission area control layer 490 is higher than that of the host of the second emission layer (EML) 115. For example, it is preferable that the hole mobility of the emission area control layer (EACL) 490 is faster than 1×10 -5 cm 2 /Vs. This makes the generation of excitons of the emission region control layer (EACL) 490 faster than excitons generated in the second emission layer (EML) 115, and thus the second emission layer (EML) 115 The excitons of may be moved away from the first emission layer (EML) 114.

The density of excitons generated in the first emission layer (EML) 114 and the second emission layer (EML) 115 is reduced by the emission area control layer (EACL) 490. Accordingly, the distribution of excitons of the second emission layer (EML) 115 is moved away from the first emission layer (EML) 114 by the emission region control layer (EACL) 490. Accordingly, the light emission area of the first emission layer (EML) 114 and the second emission layer (EML) 115 are separated to improve the aggregation of the emission area, and deterioration in the first emission unit 110 It's slowing down.

Accordingly, since the light-emitting regions are evenly distributed in the first light-emitting unit 110, it is possible to reduce the deterioration phenomenon in the first light-emitting unit 110 and induce an increase in life time, thereby improving the life of the device.

The white organic light-emitting device according to another embodiment of the present invention may be applied to a bottom emission method, a top emission method, or a good emission method.

10 is a view showing a white organic light emitting device according to another embodiment of the present invention. In describing the present embodiment, descriptions of components that are the same as or corresponding to the previous embodiment will be omitted.

In another embodiment of the present invention, the white organic light-emitting device 600 includes a first electrode 102 and a second electrode 104, and a first light-emitting unit 110 between the first and second electrodes 102 and 104 , It includes a second light-emitting unit 120 and a third light-emitting unit 130.

The first emission layer (EML) 114 of the first emission unit 110 is composed of a blue emission layer, and the first emission layer (EML) 124 of the second emission unit 120 is blue. ) It consists of a light emitting layer.

The first emission layer (EML) 134 of the third emission part 130 is composed of a red emission layer, the second emission layer (EML 135) constitutes a yellow-green emission layer, The emission area control layer (EACL) 590 is formed on the third light emitting part 130.

The emission area control layer (EACL) 590 is formed of a yellow-green emission layer.

The peak wavelength of the emission region of the blue emission layer, which is the first emission layer (EML) 114 of the first emission unit 110, may range from 440 nm to 480 nm.

The peak wavelength of the emission region of the blue emission layer, which is the first emission layer (EML) 124 of the second emission unit 120, may range from 440 nm to 480 nm.

The peak wavelength of the emission region of the red emission layer of the first emission layer (EML 134) of the third emission unit 130 may range from 600 nm to 650 nm. The second emission layer The peak wavelength of the emission region of the yellow-green emission layer of (EML) 135 may range from 510 nm to 580 nm.

The peak wavelength of the emission region of the yellow-green emission layer of the emission region control layer (EACL) 590 may be in the range of 510 nm to 580 nm.

The second emission layer (EML) 135 of the third emission unit 130 and the emission region control layer (EACL) 590 may have the same dopant and different host configurations, It is not necessarily limited thereto.

In addition to one, the host may be composed of two hosts, a hole host and a charge host. It is preferable that the hole mobility of the host included in the emission area control layer (EACL) 590 is higher than that of the host of the second emission layer (EML) 135. For example, the hole mobility of the emission area control layer (EACL) 590 is preferably faster than 1×10 -5 cm 2 /Vs. This makes the generation of excitons of the emission region control layer (EACL) 590 faster than excitons generated in the second emission layer (EML) 135, and thus the second emission layer (EML) 135 The excitons of may be moved away from the first emission layer (EML) 134.

The density of excitons generated in the first emission layer EML 134 and the second emission layer EML 135 is reduced by the emission area control layer ECL 590. For this reason, the distribution of excitons of the second emission layer (EML) 135 is moved away from the first emission layer (EML) 134 by the emission region control layer (EACL) 590. Therefore, the light emission area of the first emission layer (EML) 134 and the second emission layer (EML) 135 are separated to improve the aggregation phenomenon of the emission area, and deterioration in the third emission part 130 It's slowing down.

Accordingly, since the light-emitting regions are evenly distributed in the third light-emitting part 130, the deterioration phenomenon in the third light-emitting part 130 is reduced, and the lifespan of the device can be improved by inducing an increase in life.

The first emission layer (EML) 114 of the first emission unit 110 may be formed of a red-blue emission layer according to the configuration or characteristics of the device. The peak wavelength of the light emitting region of the red-blue light emitting layer may be in the range of 600 nm to 650 nm.

In addition, the first emission layer (EML) 124 of the second emission unit 110 may be formed of a red-blue emission layer according to the configuration or characteristics of the device. The peak wavelength of the light emitting region of the red-blue light emitting layer may be in the range of 600 nm to 650 nm.

Although the white organic light emitting device according to another embodiment of the present invention has been described for a bottom emission method, it is also possible to apply it to a top emission method or a good emission method.

As described in the present invention, when two light-emitting layers are configured in one light-emitting part, the light-emitting area of the two light-emitting layers is separated by the light-emitting area control layer, so that agglomeration of light-emitting areas between the two light-emitting layers is prevented You can see that it is. As a result, it can be seen that the light emitting area is increased by uniformly distributing the light emitting area, and the light emission intensity is also increased in the desired wavelength area.

Therefore, since the light-emitting regions are evenly distributed in the light-emitting part, it is possible to reduce the deterioration phenomenon in the light-emitting part and induce an increase in life time, thereby improving the life of the device.

One of the first light-emitting unit and the second light-emitting unit may include at least two light-emitting layers.

The at least two emission layers may include a red emission layer and a yellow-green emission layer.

The emission area control layer may be formed in a light emitting portion including the at least two emission layers.

The emission area control layer may be formed of a yellow-green emission layer.

The dopant of the emission region control layer and the yellow-green emission layer constituting the first emission unit or the second emission unit are the same, and the host may be configured differently.

The hole mobility of the host of the emission area control layer may be faster than that of the host of the yellow-green emission layer constituting the first emission part or the second emission part.

When the light emitting part including the at least two light emitting layers is the second light emitting part, the first light emitting part may include a blue light emitting layer.

One of the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit may include at least two light-emitting layers.

The at least two emission layers may include a red emission layer and a yellow-green emission layer.

The emission area control layer may be formed in a light emitting portion including the at least two emission layers.

The emission area control layer may be formed of a yellow-green emission layer.

The dopant of the emission region control layer and the yellow-green emission layer constituting the first emission unit, the second emission unit, or the third emission unit may be the same, and the host may be configured differently.

The hole mobility of the emission area control layer may be faster than that of the yellow-green emission layer constituting the first emission unit, the second emission unit, or the third emission unit.

When the light emitting part including the at least two light emitting layers is the second light emitting part, one of the first light emitting part and the third light emitting part may include a blue light emitting layer.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 200, 300, 400, 500, 600: white organic light emitting device
101: substrate 102: first electrode
104: second electrode 110: first light emitting unit
120: second light emitting unit 130: third light emitting unit
140: first charge generation layer 150: second charge generation layer
112: first hole transport layer 122: second hole transport layer
132: third hole transport layer 116: first electron transport layer
126: second electron transport layer 136: third electron transport layer
114: first light emitting layer of the first light emitting part
115: second light emitting layer of the second light emitting part
124: first light emitting layer of the second light emitting part
125: second light emitting layer of the second light emitting part
134: first light emitting layer of the third light emitting part
135: second light emitting layer of the third light emitting part
190, 290, 390, 490, 590: emission area control layer
E: light-emitting area

Claims (18)

A first light emitting unit between the first electrode and the second electrode; And
Including a second light-emitting portion on the first light-emitting portion,
At least one of the first light emitting part and the second light emitting part includes a light emitting area control layer,
At least one of the first light emitting part and the second light emitting part includes at least two light emitting layers,
The emission area control layer is formed in a light emitting portion including the at least two emission layers,
The emission area control layer is disposed adjacent to the second electrode than the at least two emission layers,
The emission area control layer is disposed to be adjacent to one of the at least two emission layers. The method of claim 1,
The at least two emission layers include a red emission layer and a yellow-green emission layer. The method of claim 2,
The white organic light-emitting device, wherein the dopant of the emission region control layer and the yellow-green emission layer constituting the first emission unit or the second emission unit are the same, and different hosts are configured. The method of claim 2,
A white organic light-emitting device in which the hole mobility of the host of the emission area control layer is faster than that of the host of the yellow-green emission layer constituting the first emission unit or the second emission unit. The method of claim 1,
When the light emitting part including the at least two light emitting layers is the second light emitting part, the first light emitting part includes a blue light emitting layer. The method of claim 1,
A white organic light-emitting device further comprising a charge generation layer between the first light-emitting part and the second light-emitting part. A first light emitting unit between the first electrode and the second electrode;
A second light-emitting part on the first light-emitting part; And
Including a third light emitting portion on the second light emitting portion,
At least one of the first light-emitting part, the second light-emitting part, and the third light-emitting part includes a light-emitting area control layer,
One of the first light-emitting part, the second light-emitting part, and the third light-emitting part includes at least two light-emitting layers,
The emission area control layer is formed in a light emitting portion including the at least two emission layers,
The emission area control layer is disposed adjacent to the second electrode than the at least two emission layers,
The emission area control layer is disposed to be adjacent to one of the at least two emission layers. The method of claim 7,
The at least two emission layers include a red emission layer and a yellow-green emission layer. The method according to claim 2 or 8,
The emission region control layer is a white organic light-emitting device consisting of the yellow-green emission layer. The method of claim 8,
A white organic light-emitting device in which the dopant of the emission region control layer and the yellow-green emission layer constituting the first emission unit, the second emission unit, or the third emission unit are the same and different hosts. The method of claim 8,
The hole mobility of the emission region control layer is faster than the hole mobility of the yellow-green emission layer constituting the first emission unit, the second emission unit, or the third emission unit. The method of claim 7,
When the light emitting part including the at least two light emitting layers is the second light emitting part, one of the first light emitting part and the third light emitting part includes a blue light emitting layer. The method according to claim 1 or 7,
Peak wavelengths of the at least two emission layers are 510nm to 580nm and 600nm to 650nm, white organic light emitting device. The method according to claim 1 or 7,
The peak wavelength of the emission region control layer is 510nm to 580nm, white organic light emitting device. A first light emitting unit between the first electrode and the second electrode;
A second light-emitting part on the first light-emitting part; And
Including a third light emitting portion on the second light emitting portion,
The first light emitting part includes a first light emitting layer having a peak wavelength of 440 nm to 480 nm,
The second light emitting part includes at least two second light emitting layers having peak wavelengths of 510 nm to 580 nm and 600 nm to 650 nm, and a third light emitting layer on the at least two light emitting layers and having a peak wavelength of 510 nm to 580 nm,
The third light-emitting unit includes a fourth light-emitting layer having a peak wavelength of 440nm to 480nm, white organic light-emitting device. The method of claim 15,
A white organic light-emitting device in which the third emission layer and the second emission layer having a peak wavelength of 510 nm to 580 nm have the same dopant and different hosts. The method of claim 15,
The hole mobility of the third emission layer is faster than the hole mobility of the second emission layer having a peak wavelength of 510nm to 580nm, white organic light emitting device. The method of claim 7 or 15,
A first charge generation layer between the first light emitting part and the second light emitting part; And
The white organic light-emitting device further comprising a second charge generation layer between the second light-emitting part and the third light-emitting part.

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