JP2014225416A - Organic electroluminescent element and organic light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element capable of controlling the color of light.SOLUTION: The organic electroluminescent element A includes plural light-emitting units 1 and three or more electrode layers 2. The three or more electrode layers 2 are configured to be connected to two or more power supply mechanisms 3. The plural light-emitting units 1 have one or more arrangements as an arrangement of neighboring light-emitting units 1 in which the electrode layer 2 is disposed between the light-emitting units 1 and the current flows in opposite directions.

Description

  The present invention relates to an organic electroluminescence element and an organic light emitting device using the same.

  A structure in which functional layers such as a hole transport layer, a light emitting layer, and an electron injection layer are laminated between an anode and a cathode provided on a substrate as an organic electroluminescence element (hereinafter also referred to as “organic EL element”) Are generally known. In the organic EL element, by applying a voltage between the anode and the cathode, light emitted from the light emitting layer is extracted outside in a planar shape.

Special table 2009-524189

  In an organic EL element, the color of light extracted from one element is usually fixed, and no one element that changes color is realized. In lighting applications, if the color can be changed, a color effect can be obtained effectively. For this reason, the toning function capable of changing the emission color can be an important function.

  Japanese Patent Application Laid-Open No. H10-260260 discloses a device that obtains mixed color light emission by alternately applying voltages to two light emitting units. However, in order to perform color matching according to the pulse width or pulse intensity of the applied voltage, the element must be driven by voltage control. In the voltage control, the current density decreases due to the increase in the voltage of the element due to energization, that is, the light emission intensity decreases, so there is a problem in long-term operation stability.

  This invention is made | formed in view of said situation, and aims at providing the organic electroluminescent element and organic light-emitting device which can be color-matched.

The organic electroluminescence device according to the present invention is an organic electroluminescence device comprising a plurality of light emitting units and three or more electrode layers,
The three or more electrode layers are configured to be connectable to two or more power feeding mechanisms,
The plurality of light emitting units have one or more arrangements in which the electrode layers are sandwiched between the light emitting units and the directions of currents are opposite to each other as the arrangement of the adjacent light emitting units.

  In the organic electroluminescence element, it is preferable that the three or more electrode layers are electrically connected to the electrode pads, and the electrode pads are arranged close to at least one end. .

  In the organic electroluminescence element, the electrode layer sandwiched between the adjacent light emitting units has the electrode layer functioning as an anode, and the electrode layer functioning as the anode is a work of the electrode layer. The difference between the value of the function and the value of the ionization potential between adjacent layers on both sides is preferably smaller than 1.0 eV in absolute value.

  In the organic electroluminescence element, the electrode layer sandwiched between the adjacent light emitting units has the electrode layer functioning as a cathode, and the electrode layer functioning as the cathode is a work of this electrode layer. The difference between the value of the function and the value of the electron affinity between the adjacent layers on both sides is preferably smaller than 1.5 eV in absolute value.

  In the organic electroluminescence element, the plurality of light emitting units are arranged such that one or more of the light emitting units are arranged in such a manner that a charge generation layer is sandwiched between the light emitting units and the direction of current is the same direction. It is a preferable aspect to have.

  In the organic electroluminescence element, of the three or more electrode layers, two electrode layers provided at both ends of the plurality of light emitting units constitute a cathode, and light is extracted from the two electrode layers. It is a preferable aspect that the electrode layer disposed on the side has a metal thin film.

  In the organic electroluminescence element, of the three or more electrode layers, two electrode layers provided at both ends of the plurality of light emitting units constitute an anode, and light extraction is performed among the two electrode layers. It is a preferable aspect that a light reflecting mechanism is provided on the electrode layer disposed on the opposite side to the side or on the opposite side of the electrode layer from the light extraction side.

  One aspect of the organic light-emitting device according to the present invention includes the above-described organic electroluminescence element, the two or more power feeding mechanisms, and a control unit that controls a current flowing from the two or more power feeding mechanisms. The control is made to make the total of the currents constant.

  One aspect of the organic light-emitting device according to the present invention includes the above-described organic electroluminescence element, the two or more power feeding mechanisms, and a control unit that controls a current flowing from the two or more power feeding mechanisms. The light emitting unit having the highest visibility among the plurality of light emitting units is configured to be controlled to be constant.

  ADVANTAGE OF THE INVENTION According to this invention, the organic electroluminescent element and organic light-emitting device which can adjust the luminescent color can be obtained.

It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 1. FIG. 3 is an exploded perspective view showing a stacked configuration of the organic electroluminescence element of Embodiment 1. 1 is a plan view showing an organic electroluminescence element of Embodiment 1. FIG. It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 2. It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 3. It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 4. It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 5. It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 6. It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 7. It is the schematic which shows the organic electroluminescent element and organic light-emitting device of Embodiment 8.

  An organic electroluminescence element A (organic EL element A) according to the present invention is an organic EL element A including a plurality of light emitting units 1 and three or more electrode layers 2. The three or more electrode layers 2 are configured to be connectable to two or more power feeding mechanisms 3. The plurality of light emitting units 1 have one or more arrangements in which the electrode layers 2 are sandwiched between the light emitting units 1 and the directions of currents are reversed as arrangements of the adjacent light emitting units 1. According to the organic EL element A of the present invention, the organic EL element A capable of adjusting the emission color can be obtained.

  In the organic EL element A, the three or more electrode layers 2 are electrically connected to the electrode pads 4, and the electrode pads 4 are arranged close to at least one end. It is preferable. This facilitates electrical connection. Further, since the current distribution becomes more uniform, more uniform light emission can be obtained.

  In the organic EL element A, the electrode layer 2 sandwiched between the adjacent light emitting units 1 has the electrode layer 2 functioning as an anode, and the electrode layer 2 functioning as the anode includes It is preferable that the difference between the work function value of the electrode layer 2 and the ionization potential value between adjacent layers on both sides is smaller than 1.0 eV in absolute value. Thereby, it becomes easy to inject holes into the layer adjacent to the electrode layer 2 functioning as an anode, and the luminous efficiency can be increased.

  In the organic EL element A, the electrode layer 2 sandwiched between the adjacent light emitting units 1 has the electrode layer 2 functioning as a cathode, and the electrode layer 2 functioning as the cathode is The difference between the value of the work function of the electrode layer 2 and the value of the electron affinity between adjacent layers on both sides is preferably smaller than 1.5 eV. Thereby, it becomes easy to inject electrons into the layer adjacent to the electrode layer 2 functioning as a cathode, and the luminous efficiency can be increased.

  In the organic EL element A, the plurality of light emitting units 1 are arranged in such a manner that the light emitting units 1 are adjacent to each other, the charge generation layer 5 is sandwiched between the light emitting units 1, and the directions of the currents are the same. It is one preferred embodiment that has one or more arrangements. Thereby, the power feeding structure can be simplified and the electrical characteristics can be enhanced.

  In the organic EL element A, of the three or more electrode layers 2, two electrode layers 2 provided at both ends of the plurality of light emitting units 1 constitute a cathode, and the two electrode layers 2 Of these, the electrode layer 2 disposed on the light extraction side preferably has a metal thin film 6. Thereby, the electron injection property of the electrode layer 2 which comprises a cathode can be improved, and luminous efficiency can be improved.

  In the organic EL element A, of the three or more electrode layers 2, the two electrode layers 2 provided at both ends of the plurality of light emitting units 1 constitute an anode, and the two electrode layers 2 It is preferable that the light reflection mechanism 7 is provided on the electrode layer 2 disposed on the side opposite to the light extraction side or on the side opposite to the light extraction side from the electrode layer 2. It is. Thereby, more light can be extracted to the outside by light reflection, so that the light emission efficiency can be improved.

  The organic light-emitting device according to the present invention includes the organic EL element A, the two or more power feeding mechanisms 3, and a control unit 8 that controls a current flowing from the two or more power feeding mechanisms 3. It is a preferable aspect that the control unit 8 is configured to perform control to keep the total current constant. Further, the control unit 8 is another aspect that is preferably configured to perform control to make the current of the light emitting unit 1 having the highest visibility among the plurality of light emitting units 1 constant. . According to the organic light emitting device, since the current can be controlled by the control unit 8, the color can be changed without changing the brightness so much, so that the color can be effectively adjusted.

  Hereinafter, embodiments embodying the present invention will be described. It goes without saying that the present invention is not limited to these embodiments.

[Embodiment 1]
FIG. 1 schematically shows an organic electroluminescence element A (organic EL element A) and an organic light-emitting device according to Embodiment 1. 2 and 3 show the organic EL element A of the first embodiment. The organic EL element A in FIGS. 2 and 3 constitutes the organic light emitting device in FIG. 1 by being electrically connected to circuit wiring or the like. That is, the organic light-emitting device of Embodiment 1 has the organic EL element A of Embodiment 1 as a component.

  The organic light-emitting device of Embodiment 1 includes an organic EL element A, two or more power feeding mechanisms 3, and a control unit 8 that controls a current flowing from the two or more power feeding mechanisms 3. In FIG. 1, the organic EL element A is shown in a layer configuration, and the other parts are shown in a block diagram using connection wirings 11.

  As shown in FIG. 1, the organic EL element A includes a plurality of light emitting units 1 and three or more electrode layers 2. In the organic EL element A, three or more electrode layers 2 are configured to be connectable to two or more power feeding mechanisms 3. The plurality of light emitting units 1 have at least one arrangement in which the electrode layers 2 are sandwiched between the light emitting units 1 and the directions of currents are opposite to each other as arrangements of the adjacent light emitting units 1. Accordingly, since power can be supplied for each light emitting unit 1, the intensity of light emission can be changed for each light emitting unit 1, so that the emission spectrum can be changed and the emission color can be changed. As a result, toning can be performed.

  The organic EL element A of Embodiment 1 has a substrate 9. The substrate 9 serves as a base material that supports the organic light-emitting laminate including the plurality of light-emitting units 1 and the plurality of electrode layers 2. When the organic EL element A is formed to be stacked, the layers are stacked on the substrate 9.

  In Embodiment 1, the light emitting unit 1 is comprised by three. The light emitting unit 1 is a laminated structure that emits light when a voltage is applied between an anode and a cathode. Here, the light emitting units 1 are numbered from the substrate 9 side. That is, the light emitting unit 1 closest to the substrate 9 is defined as the first light emitting unit 1a. The light emitting unit 1 adjacent to the first light emitting unit 1a on the side opposite to the substrate 9 is defined as a second light emitting unit 1b. The light emitting unit 1 adjacent to the second light emitting unit 1b on the side opposite to the substrate 9 is defined as a third light emitting unit 1c. Similarly, when there are four or more light emitting units 1, they are numbered as fourth, fifth,...

  The electrode layer 2 constitutes an electrode for applying a voltage to the organic EL element A. In the organic EL element A of Embodiment 1, the electrode layer 2 is 3 or more, which is different from a normal element. The electrode layer 2 includes an end electrode layer and an intermediate electrode layer. The electrode layer 2 disposed outside the light emitting unit 1 located on the outermost side among the plurality of light emitting units 1 is an end electrode layer. The number of end electrode layers is two. The electrode layer 2 disposed between the adjacent light emitting units 1 and 1 is an intermediate electrode layer. The organic EL element A has a configuration in which a plurality of light emitting units 1 are sandwiched between two end electrode layers. Each light emitting unit 1 is configured to be sandwiched between two electrode layers 2 (end electrode layer or intermediate electrode layer).

  The end electrode layers are close to the substrate 9 and far from the substrate 9. One end electrode layer is provided on the substrate 9 side of the light emitting unit 1 closest to the substrate 9, and the other end electrode layer is provided on the side opposite to the substrate 9 of the light emitting unit 1 farthest from the substrate 9. Here, the end electrode layers are numbered from the substrate 9 side. Of the two end electrode layers, the end electrode layer on the substrate 9 side is defined as a first end electrode layer 2a. The first end electrode layer 2 a is the electrode layer 2 closest to the substrate 9 among the plurality of electrode layers 2. Of the two end electrode layers, the end electrode layer opposite to the substrate 9 is defined as a second end electrode layer 2b. The second end electrode layer 2 b is the electrode layer 2 farthest from the substrate 9 among the plurality of electrode layers 2.

  The intermediate electrode layer is an electrode disposed between the two light emitting units 1. The organic EL element A of Embodiment 1 is characterized by having an intermediate electrode layer. The number of intermediate electrode layers may be one or plural (two or more). The number of intermediate electrode layers is smaller than the number of light emitting units 1.

  The organic EL element A of Embodiment 1 has two intermediate electrode layers. Here, the intermediate electrode layer is numbered from the substrate 9 side. The intermediate electrode layer closest to the substrate 9 side is defined as the first intermediate electrode layer 2p. The intermediate electrode layer closest to the substrate 9 side next to the first intermediate electrode layer 2p is defined as the second intermediate electrode layer 2q. Similarly, when there are three or more intermediate electrode layers, they are numbered as third, fourth,... In addition, when there is one intermediate electrode layer as in an embodiment described later, only the first intermediate electrode layer 2p is present. In this case, the intermediate electrode layer may be defined as the first intermediate electrode layer 2p.

  The organic light emitting device has a plurality of electrode pads 4. The plurality of electrode layers 2 are electrically connected to electrode pads 4 corresponding to the electrode layers 2. The electrode layers 2 are electrically insulated from each other, and the corresponding electrode pads 4 are also electrically insulated from each other. The connection between the electrode layer 2 and the electrode pad 4 can be made by an electrode lead portion 10 formed by drawing out the electrode layer 2.

  FIG. 2 shows the laminated structure of the organic EL element A in an exploded manner. In FIG. 2, each layer or layer assembly is broken up and down. Although the light emitting unit 1 can be composed of a plurality of layers, it is shown here as a single laminate. Moreover, although the electrode layer 2 can have a multilayer structure, it is shown here as a single laminate.

  As shown in FIG. 2, the organic EL element A according to Embodiment 1 is configured such that each layer or a collection of layers is stacked on a substrate 9. A laminate from the first end electrode layer 2a to the second end electrode layer 2b is an organic light emitting laminate. In the first embodiment, the organic light emitting laminate includes the first end electrode layer 2a, the first light emitting unit 1a, the first intermediate electrode layer 2p, the second light emitting unit 1b, the second intermediate electrode layer 2q, It has a laminated structure in which the three light emitting units 1c and the second end electrode layer 2b are arranged in this order. Each layer constituting the organic EL element A is laminated in a pattern shape in which each electrode layer 2 is not electrically short-circuited. For example, each light emitting unit 1 is formed so as to cover the adjacent electrode layer 2 on the substrate 9 side, whereby contact of each electrode layer 2 can be suppressed. Alternatively, each electrode layer 2 can be insulated by providing the insulating layer in an appropriate pattern shape.

  Each electrode layer 2 is formed with a portion protruding outward from the light emitting portion of the organic EL element A, and the protruding portion constitutes the electrode lead-out portion 10. By providing the electrode lead portion 10, electricity can be supplied to the electrode layer 2.

  The electrode lead portion 10 of the first end electrode layer 2a is a first end electrode lead portion 10a. The electrode lead portion 10 of the first intermediate electrode layer 2p is a first intermediate electrode lead portion 10p. The electrode lead portion 10 of the second intermediate electrode layer 2q is a second intermediate electrode lead portion 10q. The electrode lead portion 10 of the second end electrode layer 2b is a second end electrode lead portion 10b. In FIG. 1, the electrode lead-out part 10 is drawn with wiring, but the electrode lead-out part 10 may be a part of the layer drawn out as shown in FIG. 2. Each electrode lead-out portion 10 may be formed using the same material as that of the corresponding electrode layer 2 or may be formed using a different material.

  FIG. 3 shows the organic EL element A in plan view. The plan view refers to a case viewed from a direction perpendicular to the light emitting surface. That is, the plan view is a case when viewed from a direction perpendicular to the surface of the substrate 9. FIG. 3 shows a state seen from the organic light emitting laminate side.

  In the organic EL element A, sealing is usually performed to protect the organic light emitting laminate. By sealing, deterioration due to moisture can be suppressed or protected from physical impact. In FIG. 3, a region to be sealed is indicated by a broken line as a sealing region S.

  The electrode lead portion 10 is drawn from the inside of the sealing region S to the outside. As a result, electricity can be supplied from the external power supply mechanism 3 to the organic EL element A. In the first embodiment, the electrode pad 4 is provided on the substrate 9. The electrode lead-out part 10 is electrically connected by contacting the electrode pad 4. As can be seen from FIG. 1, when the organic light emitting device is formed, the connection wiring 11 is connected to each electrode pad 4 correspondingly.

  In the organic EL element A, it is preferable that each electrode pad 4 is arranged close to at least one end. Thereby, the connection of wiring becomes easy. Moreover, when the part which supplies electricity to each electrode layer 2 is near, it can suppress that electric current distribution changes for every electrode layer 2, and can obtain more uniform light emission.

  As shown in FIG. 3, in Embodiment 1, the organic EL element A has a quadrangular shape, and all of the electrode pads 4 corresponding to each electrode layer 2 are arranged on at least one side of the quadrangular shape. Therefore, it becomes possible to supply electricity to all the electrode layers 2 from one side of the square shape, and the current distribution can be stabilized. In FIG. 3, the electrode pads 4 corresponding to the electrode layers 2 are arranged side by side. It can be said that the electrode pads 4 are arranged in a row.

  In the organic EL element, it is preferable to provide a plurality of electrode lead portions 10 in one electrode layer 2. As a result, the number of parts for supplying electricity increases, so that the current distribution can be further stabilized. The number of electrode lead-out portions 10 and the number of electrode pads 4 are usually equal. Therefore, in this case, one electrode layer 2 is connected to a plurality of electrode pads 4. As can be seen from FIGS. 2 and 3, in the first embodiment, each electrode layer 2 has two electrode lead portions 10. The two electrode lead portions 10 are connected to the corresponding electrode pads 4. In the first embodiment, all of the electrode pads 4 corresponding to each electrode layer 2 (four types of electrode pads 4) are provided on one side of the quadrangular shape and one side facing the one side in the quadrangular shape. FIG. 3 shows a state in which the electrode pads 4 are provided on the left and right sides. Therefore, it is possible to supply power to each electrode layer 2 from a plurality of locations, and the current distribution can be further stabilized. In FIG. 1, the electrode lead portions 10 and the electrode pads 4 corresponding to each electrode layer 2 are shown as one for easy understanding of the circuit configuration, but as shown in FIGS. 2 and 3. These may be plural.

  As shown in FIG. 3, in the first embodiment, the electrode lead portions 10 and the electrode pads 4 in each electrode layer 2 are arranged point-symmetrically with respect to the center of the light emitting region. For example, in FIG. 3, one of the two electrode pads 4 connected to the first end electrode lead portion 10a is formed at the lower right corner, and the other is formed at the upper left corner. The other electrode lead portions 10 (10b, 10p, 10q) and the corresponding electrode pads 4 are similarly arranged point-symmetrically. The center of the light emitting region that is the center of point symmetry may be the center of gravity in plan view of the organic light emitting stack (laminated body from the first end electrode layer 2a to the second end electrode layer 2b). As described above, when the electrode lead portion 10 and the electrode pad 4 are formed symmetrically, electricity can be supplied symmetrically with respect to the center of the light emitting region, and the current distribution can be further stabilized. Furthermore, stable light emission can be obtained.

  In the first embodiment, the rectangular organic EL element A is illustrated in plan view, but the shape of the organic EL element A is not limited to a square. For example, the organic EL element A may have another polygonal shape, or a circular or elliptical shape. It is preferable that the electrode pads 4 are arranged on one side as well in other polygonal shapes (pentagon, hexagon, octagon, etc.). Further, it is preferable that the electrode pad 4 and the electrode lead-out portion 10 are arranged point-symmetrically also in other polygonal shapes (pentagon, hexagon, octagon, etc.). In the polygonal shape, the electrode pads 4 corresponding to the electrode layers 2 can be arranged close to one side. The polygonal shape is not limited to a regular polygon. The organic EL element A in FIG. 3 is rectangular in plan view. By the way, even when the organic EL element A is formed in a circular shape or an elliptical shape, it is preferable that the electrode pad 4 be arranged close to the end portion and that the electrode pad 4 be arranged point-symmetrically. Can be understood from the above description.

  As shown in FIG. 1, in the organic light emitting device, the electrode pad 4 is electrically connected to the power supply mechanism 3 via the connection wiring 11. The power feeding mechanism 3 and the electrode pad 4 are connected in a current direction that can supply electricity to the organic EL element A. The number of power supply mechanisms 3 is usually smaller than the number of electrode layers 2. The number of power feeding mechanisms 3 is usually smaller than the number of light emitting units 1.

  One aspect of the power feeding mechanism 3 is a power source 3a. Power can be easily supplied by the power source 3a. In FIG. 1, the power feeding mechanism 3 is illustrated by a power source 3a. Further, the power feeding mechanism 3 may be one that supplies electricity by diverting electricity from one power source 3a. That is, the power feeding mechanism 3 can be configured by a shunt. Thereby, the organic EL element A can emit light by connection with the single power source 3a.

  In the first embodiment, three power feeding mechanisms 3 are provided. There may be at least two power supply mechanisms 3. There may be four or more power supply mechanisms 3. However, in order not to complicate the apparatus, it is preferable that the number of power feeding mechanisms 3 is smaller than the number of electrode layers 2.

  Each power feeding mechanism 3 (power supply 3 a) is electrically connected to the control unit 8 through the connection wiring 11. The control unit 8 controls the current flowing from the two or more power feeding mechanisms 3. The control unit 8 has a function of controlling the amount of current flowing between the electrodes of the light emitting unit 1 from each power feeding mechanism 3 and the amount of voltage applied between the electrodes. By providing the control unit 8, it is possible to set a current amount suitable for flowing to each light emitting unit 1. Therefore, the toning property can be improved. The control unit 8 can be configured by a computer or the like.

  Whether each electrode layer 2 functions as an anode or a cathode is determined by the direction of current from the power supply mechanism 3. That is, the plus (+) and minus (−) of the electrode layer 2 is determined depending on the connection method between the electrode layer 2 and the power feeding mechanism 3.

  In the first embodiment, the first end electrode layer 2a and the second intermediate electrode layer 2q are configured as cathodes. The second end electrode layer 2b and the first intermediate electrode layer 2p are configured as anodes. In FIG. 1, “+” is described for the anode and “−” is described for the cathode. The direction of the current is from the first intermediate electrode layer 2p to the first end electrode layer 2a, from the first intermediate electrode layer 2p to the second intermediate electrode layer 2q, and from the second end electrode layer 2b to the second intermediate electrode layer 2q. There are three directions.

  In the organic EL element A, the arrangement of the light emitting units 1 adjacent to each other has at least one arrangement in which the direction of current is opposite. In the first embodiment, there are two pairs of adjacent light emitting units 1 whose current directions are opposite.

  As a pair of the adjacent light emitting units 1 whose current directions are opposite, there is a pair constituted by the first light emitting unit 1a and the second light emitting unit 1b. In the pair of the first light emitting unit 1a and the second light emitting unit 1b, the direction of the current flowing through each light emitting unit 1 is opposite. Therefore, different power can be applied to the first light emitting unit 1a and the second light emitting unit 1b. Therefore, the 1st light emission unit 1a and the 2nd light emission unit 1b can change the ratio of emitted light intensity, and can change the color taken out as a whole.

  As a pair of the adjacent light emitting units 1 whose current directions are opposite, there is a pair constituted by the second light emitting unit 1b and the third light emitting unit 1c. In the pair of the second light emitting unit 1b and the third light emitting unit 1c, the direction of the current flowing through each light emitting unit 1 is opposite. Therefore, different power can be applied to the second light emitting unit 1b and the third light emitting unit 1c. Therefore, the second light emitting unit 1b and the third light emitting unit 1c can change the ratio of the light emission intensity, and can change the color taken out as a whole.

  As described above, when the pair of adjacent light emitting units 1 has at least one arrangement in which the direction of current is opposite, power can be supplied to each light emitting unit 1. Then, since the intensity of light emission can be changed for each light emitting unit 1, it is possible to adjust the overall emission color and perform color matching.

  In order to effectively perform toning, it is preferable that the color emitted from each light emitting unit 1 is a different color. For example, the organic EL element A having three light emitting units 1 as in Embodiment 1 can be composed of three light emitting units 1 that emit red, one that emits green, and one that emits blue. . By having three colors of red, green, and blue, light of various colors can be emitted. In particular, white light emission can be easily obtained. Further, when there are two light emitting units 1, white light emission is possible by configuring the light emitting unit 1 to emit yellow or orange and the light emitting unit 1 emitting blue. Note that the color emitted by the light emitting unit 1 may be a color generated by one light emitting material or a color generated by a plurality of light emitting materials. In the case of using a plurality of light emitting materials, a case where the light emitting layer has a multilayer structure or a mixed structure in which a plurality of light emitting materials are mixed in one light emitting layer is included.

  The light emitting unit 1 is composed of layers such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. The light emitting unit 1 usually has a multilayer structure. In a preferred embodiment, the light emitting unit 1 is layered in the order (hole injection layer to electron injection layer) from the anode side. At that time, a part of the layers may be omitted as appropriate as long as driving is possible.

  The light emitting unit 1 has at least one light emitting layer. The light emitting layer is a layer containing a light emitting material (dopant). The light emitting layer is usually composed of a dopant and a host material. The light emitting layer may have a single layer structure or a multilayer structure. One light emitting layer may contain a plurality of light emitting materials. The layers other than the light emitting layer can be omitted as appropriate as long as the unit emits light. As the light emitting material, either a phosphorescent light emitting material or a fluorescent light emitting material can be used.

  Each light emitting unit 1 is preferably composed of either a phosphorescent light emitting unit or a fluorescent light emitting unit. The phosphorescent light emitting unit is a light emitting unit 1 including a phosphorescent light emitting material. The fluorescent light emitting unit is a light emitting unit 1 including a fluorescent light emitting material. The phosphorescent light emitting unit preferably contains only a phosphorescent light emitting material. The fluorescent light emitting unit preferably includes only a fluorescent light emitting material.

  It is a preferable aspect that a plurality of the light emitting units 1 are configured by a fluorescent light emitting unit and the other portions are configured by a phosphorescent light emitting unit. Thereby, for each light emitting unit 1, a structure suitable for the fluorescent light emitting material and the phosphorescent light emitting material can be adopted, and both a long life and high efficiency can be achieved. The plurality of light emitting units 1 is another embodiment in which it is preferable that all of the light emitting units 1 be constituted by phosphorescent light emitting units. Thereby, since phosphorescence emission is relatively high in efficiency, an element with high light extraction efficiency can be configured.

  The organic EL element A may have a structure for extracting light from the substrate 9 side (so-called bottom emission structure), or may have a structure for extracting light from the side opposite to the substrate 9 (so-called top emission structure). Good. In the case of the bottom emission structure, a light scattering structure may be provided on one or both of the element inner side and the element outer side of the substrate 9. Thereby, more light can be extracted outside. In the case where light is extracted from the substrate 9 side, the substrate 9 preferably has light transmittance.

  The organic EL element A of Embodiment 1 has an electrode layer 2 that functions as an anode as the electrode layer 2 sandwiched between adjacent light emitting units 1. The electrode layer 2 corresponding to this condition is the first intermediate electrode layer 2p. At this time, the first intermediate electrode layer 2p, which is the electrode layer 2 functioning as the anode, has an absolute difference between the value of the work function of the electrode layer 2 and the value of the ionization potential between adjacent layers on both sides. The value is preferably smaller than 1.0 eV. Thereby, since holes can be smoothly flowed from the anode toward the light emitting layer, the light emission efficiency can be increased.

  The first intermediate electrode layer 2p is adjacent to and in contact with the layer on the first intermediate electrode layer 2p side (second end electrode layer 2b side) most of the layers constituting the first light emitting unit 1a. The layer in contact with the first intermediate electrode layer 2p in the first light emitting unit 1a may be a hole injection layer or a hole transport layer. The first intermediate electrode layer 2p is adjacent to and in contact with the layer on the first intermediate electrode layer 2p side (first end electrode layer 2a side) of the layers constituting the second light emitting unit 1b. The layer in contact with the first intermediate electrode layer 2p in the second light emitting unit 1b may be a hole injection layer or a hole transport layer. Therefore, when the ionization potential of the hole injection layer or the hole transport layer, which is a layer adjacent to the first intermediate electrode layer 2p, is close to the work function of the first intermediate electrode layer 2p, the movement of holes is facilitated. Can do it. In particular, in the intermediate electrode layer, since it is required to inject holes into both of the two adjacent light emitting units 1, the relationship between the work function and the ionization potential is established on both sides of the electrode layer 2. It is preferable to do.

  By the way, this relationship can be applied also when the end electrode layer which functions as an anode exists. In the first embodiment, the second end electrode layer 2b is configured as an anode. Therefore, the second end electrode layer 2b, which is the electrode layer 2 functioning as an anode, has an absolute value of 1 between the work function value of the electrode layer 2 and the ionization potential value between adjacent layers. It is preferable to be smaller than 0.0 eV.

  The smaller the difference between the work function value of the electrode layer 2 functioning as the anode and the ionization potential value between adjacent layers, the better. Therefore, the lower limit of this difference is zero.

  The organic EL element A of Embodiment 1 has an electrode layer 2 that functions as a cathode as the electrode layer 2 sandwiched between adjacent light emitting units 1. The electrode layer 2 corresponding to this condition is the second intermediate electrode layer 2q. At this time, the second intermediate electrode layer 2q which is the electrode layer 2 functioning as the cathode has an absolute difference between the work function value of the electrode layer 2 and the electron affinity value between the adjacent layers on both sides. The value is preferably smaller than 1.5 eV. Thereby, electrons can flow smoothly from the cathode toward the light emitting layer, so that the light emission efficiency can be increased.

  The second intermediate electrode layer 2q is adjacent to and in contact with the layer on the second intermediate electrode layer 2q side (second end electrode layer 2b side) most of the layers constituting the second light emitting unit 1b. The layer in contact with the second intermediate electrode layer 2q in the second light emitting unit 1b may be an electron injection layer or an electron transport layer. The second intermediate electrode layer 2q is adjacent to and in contact with the layer on the second intermediate electrode layer 2q side (first end electrode layer 2a side) most of the layers constituting the third light emitting unit 1c. The layer in contact with the second intermediate electrode layer 2q in the third light emitting unit 1c may be an electron injection layer or an electron transport layer. Therefore, if the electron affinity of the electron injection layer or the electron transport layer, which is a layer adjacent to the second intermediate electrode layer 2q, is close to the work function of the second intermediate electrode layer 2q, the electron movement can be facilitated. is there. In particular, in the intermediate electrode layer, since it is required to inject electrons into both of the two adjacent light emitting units 1, the relationship between the work function and the electron affinity as described above is established on both sides of the electrode layer 2. It is preferable.

  By the way, this relationship can be applied also when the end electrode layer which functions as a cathode exists. In the first embodiment, the first end electrode layer 2a is configured as a cathode. Therefore, the first end electrode layer 2a, which is the electrode layer 2 functioning as the cathode, has an absolute value of 1 between the work function value of the electrode layer 2 and the electron affinity value between the adjacent layers. It is preferred that it be less than 5 eV.

  The smaller the difference between the work function value of the electrode layer 2 functioning as the cathode and the electron affinity between the adjacent layers, the better. Therefore, the lower limit of this difference is zero.

  In the organic light emitting device, the current applied to each light emitting unit 1 can be adjusted by the control unit 8. Therefore, the intensity ratio of light generated from the light emitting unit 1 can be changed. For example, consider a case where the organic EL element A has three light emitting units 1 of red, green, and blue and emits white light as a whole. In this case, if the ratio of the current passed through the red light emitting unit 1 is increased, a reddish color can be emitted. As redness increases, color rendering can be enhanced. Moreover, if the ratio of the current passed through the blue light emitting unit 1 is increased, a color with a more bluish color can be emitted. When the bluish color increases, the whiteness as a whole increases and white light emission with a high color temperature can be obtained. In this way, the toning can be easily performed under the control of the control unit 8.

  The organic light emitting device preferably has an external input means for giving a control instruction to the control unit 8. The external input means may be, for example, a plurality of buttons or switches for changing colors. Specifically, for example, two types of buttons can be provided: a button for instructing to increase the color temperature of the emission color and a button for instructing to decrease the color temperature of the emission color. This means is particularly useful in lighting devices. When the external input unit is provided, it can be changed to a desired color by giving an instruction from the external input unit, and an illumination device having a toning function can be easily obtained.

  In the toning of the organic light emitting device, the amount of current flowing through each light emitting unit 1 changes before and after the color change. Brightness as well as color is an important factor for light obtained from an organic light emitting device. Therefore, it is preferable that the brightness is maintained before and after the color change. If the color can be changed while maintaining the brightness as much as possible, the color can be changed with the same degree of brightness, so that the toning can be performed effectively.

  In the organic light emitting device, it is a preferable aspect that the control unit 8 is configured to perform control to make the total current constant. Thereby, since the emission color can be changed without changing the brightness so much, it is possible to perform toning effectively. If the total current is constant, the overall current flowing before and after the color change is the same, so the overall brightness is maintained. The sum of currents means a sum of currents flowing through the plurality of light emitting units 1. In the first embodiment, the sum of the three currents of the current of the first light emitting unit 1a, the current of the second light emitting unit 1b, and the current of the third light emitting unit 1c is the sum of the currents of the entire organic EL element A. . The direction in which the current flows does not matter.

  When toning is performed, the amount of current flowing through each light emitting unit 1 is changed. At this time, if the amount of current flowing through one light emitting unit 1 is reduced, the total amount of current decreases. Then, since the total amount of current decreases, the amount of light extracted from the entire organic EL element A is reduced, and the light may be darker than the light before the change. Conversely, if the amount of current flowing through one light emitting unit 1 is increased, the total amount of current increases. Then, since the total amount of current increases, the amount of light extracted from the entire organic EL element A increases, and the light may become brighter than the light before the change. If the light intensity is different from before and after the change, the brightness change may be felt larger than the color change, and a desired toning effect may not be obtained. Therefore, it is preferable to control the total current so that it is constant.

  When the total current is constant, the ratio of currents flowing through the light emitting units 1 changes. For example, if the total current of each light emitting unit 1 before change is 1 and the current ratio is 0.35: 0.35: 0.3, the total current is set to a constant value 1, and the current ratio is changed to 0. .3: 0.35: 0.35. Then, the color can be changed while maintaining the same brightness as much as possible. Therefore, it is possible to perform toning effectively.

  In the organic light emitting device, it is preferable that the control unit 8 be configured to perform control to make the current of the light emitting unit 1 having the highest visibility among the plurality of light emitting units 1 constant. is there. As a result, the emission color can be changed without causing a significant change in brightness, so that color matching can be performed effectively. The brightness depends largely on the human senses. When a certain color changes, there are cases where it is felt that the brightness has changed greatly depending on the color, and cases where it does not. At that time, if the current amount of the light emitting unit 1 with high visibility, that is, the light emitting unit 1 in which the brightness is easy to be recognized by a person, is constant, the brightness is felt even if the color changes. And toning can be performed effectively.

  The light emitting unit 1 having the highest visibility may be the light emitting unit 1 in which the peak of the emission spectrum generated from the light emitting unit 1 is closest to the wavelength of 550 nm. This is because light in the vicinity of a wavelength of 550 nm has higher visibility than other wavelengths. The light emission spectrum generated from the light emitting unit 1 is the light emission spectrum of the light emitting material when there is one light emitting material, and the light emission spectrum obtained by mixing them when there are a plurality of light emitting materials.

  The light near the wavelength of 550 nm may be light emitted from the green light emitting material. Therefore, when the organic EL element A has a green light emitting material, it is a preferable aspect to make the current of the light emitting unit 1 having the green light emitting material constant. When there are a plurality of light emitting units 1 having a green light emitting material, it is a preferable aspect that the current of the light emitting unit 1 having a strong intensity at a wavelength closer to a wavelength of 550 nm is made constant. Note that yellow light emitting materials and orange light emitting materials also exist as materials that emit light in the vicinity of a wavelength of 550 nm. In that case, the light-emitting unit 1 that emits strong intensity near the wavelength of 550 nm can be selected as the light-emitting unit 1 that keeps the current constant.

  When performing the color matching, the ratio of the current flowing through each light emitting unit 1 is changed. At this time, if the current flowing through one light emitting unit 1 is relatively reduced, the amount of color emitted from the light emitting unit 1 is reduced. Conversely, when the current flowing through one light emitting unit 1 is relatively increased, the amount of color emitted from the light emitting unit 1 increases. At this time, if the amount of color in which the brightness is easily perceived changes, the brightness change may be felt larger than the color change, and a desired toning effect may not be obtained. At this time, the current of the light emitting unit 1 with high visibility is kept constant without changing, and the current ratio is changed by changing the current of the other light emitting units 1. Then, since the amount of light from the light emitting unit 1 with high visibility does not change so much, it is possible to minimize the change in brightness as much as possible. Therefore, it is preferable to control the current of the light emitting unit 1 having high visibility to a constant level.

  When changing the emission color while keeping the current of the light emitting unit 1 having high visibility constant, the current flowing through the other light emitting units 1 changes. The total total current may vary. For example, when the current ratio of each light emitting unit 1 before the change is 0.35: 0.35: 0.3 and the light emitting unit 1 with high visibility is the first, the current of the light emitting unit 1 is kept constant. The current of the other light emitting unit 1 is changed to 0.35: 0.3: 0.3. Then, the color can be changed while maintaining the same brightness as much as possible. Therefore, it is possible to perform toning effectively.

  Hereinafter, the material used for the organic EL element A described above and the production of the organic EL element A will be described.

  As the substrate 9, an appropriate substrate material suitable for forming the organic EL element A can be used. For example, a glass substrate, a resin substrate, or the like can be used. If a glass substrate is used, a transparent substrate having high light extraction properties and high strength can be easily obtained.

  The electrode layer 2 (anode and cathode) can be formed as the light transmissive electrode layer 2 by using an appropriate conductive material. Note that the end electrode layer opposite to the light extraction side may have light reflectivity.

  The plurality of electrode layers 2 are preferably formed using the same material. Thereby, the electrode layer 2 can be formed easily. For example, if the electrode layer 2 is made of a transparent electrode material, the organic EL element A that can extract light from each light emitting unit 1 can be formed.

  Of the plurality of electrode layers 2, it is preferable that the end electrode layer opposite to the light extraction side is configured as a light reflective electrode and the other electrode layers 2 are configured as light transmissive electrodes. Thereby, more light can be extracted outside using light reflection. In this case, it is more preferable that the electrode layer 2 having optical transparency is made of the same material. Thereby, the electrode layer 2 can be formed easily. In the first embodiment, in the case of the bottom emission structure, the second end electrode layer 2b can be made light reflective, and the other electrode layers 2 (the first end electrode layer 2a and the intermediate electrode layer) can be made light transmissive. . In the first embodiment, in the case of the top emission structure, the first end electrode layer 2a can be made light reflective, and the other electrode layers 2 (second end electrode layer 2b and intermediate electrode layer) can be made light transmissive. .

When the electrode layer 2 constitutes an anode, it is preferable to use an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function as the anode. When light is extracted from the anode, the anode can be constituted by a transparent conductive film. Examples of the configuration of the anode include a metal thin film, a transparent metal oxide film, and an organic conductive film. Examples of materials for the anode include metals such as gold, CuI, ITO (indium-tin oxide), SnO ₂ , ZnO, IZO (indium-zinc oxide), conductive polymers such as PEDOT and polyaniline, and any A conductive polymer doped with an acceptor or the like, or a conductive light-transmitting material such as a carbon nanotube can be used. If ITO or the like is used, a highly conductive transparent electrode can be formed.

  When the electrode layer 2 forms a cathode, it is preferable to use an electrode material made of a metal, an alloy, an electrically conductive compound, and a mixture thereof having a low work function as the cathode. Examples of the material for the cathode include alkali metals, alkaline earth metals, and alloys of these with other metals. Specific examples of the cathode material include, for example, aluminum, silver, sodium, sodium-potassium alloy, lithium, magnesium, magnesium-silver mixture, magnesium-indium mixture, and aluminum-lithium alloy. Further, one or more conductive materials such as metals may be laminated and used. Examples include an alkali metal / Al laminate, an alkaline earth metal / Al laminate, an alkaline earth metal / Ag laminate, a magnesium-silver alloy / Ag laminate, and the like. If aluminum, silver, or the like is used, a highly reflective electrode can be formed.

As the electrode layer 2 constituting the intermediate electrode layer, BCP: Li, ITO, NPD: MoO ₃ , Liq: Al, or the like can be used in addition to the anode or cathode material described above. For example, the electrode layer 2 can have a two-layer structure in which a first layer made of BCP: Li is arranged on the anode side and a second layer made of ITO is arranged on the cathode side. The intermediate electrode layer may be composed of a metal thin film. The metal thin film can transmit light. For example, the electrode layer 2 can be formed of Ag, Al, or the like.

  By the way, in the embodiment described later, the organic EL element A having the charge generation layer 5 will be described. However, the charge generation layer 5 can be formed of the same material as that described for the electrode layer 2. It is a preferred embodiment that the charge generation layer 5 and the electrode layer 2 are made of the same material. Thereby, manufacture becomes easy. At this time, if electrically connected to the power supply mechanism 7, the electrode layer 2 functions as the electrode layer 2. If not electrically connected to the power supply mechanism 7, the electrode layer 2 and the layer that functions as the charge generation layer 5 are used. The charge generation layer 5 can be formed.

  The light emitting layer is formed including a guest material which is a dopant compound (light emitting dopant) and a host material containing the dopant compound.

CBP, CzTT, TCTA, mCP, CDBP, or the like can be used as a host for the phosphorescent light emitting layer. Ir (ppy) ₃ , Ir (ppy) ₂ (acac), Ir (mppy) _3, or the like can be used as the phosphorescent green light-emitting dopant. As the phosphorescent red light emitting dopant, Btp ₂ Ir (acac), Bt ₂ Ir (acac), PtOEP, or the like can be used. As the phosphorescent blue light-emitting dopant, FIr (pic) or the like can be used. The doping concentration of the phosphorescent light emitting dopant can be 1 to 40% by mass.

Alq ₃ , ADN, BDAF, TBADN, or the like can be used as a host for the fluorescent light-emitting layer. As the fluorescent green light-emitting dopant, C545T, DMQA, coumarin 6, rubrene, or the like can be used. TBP, BCzVBi, perylene, or the like can be used as the fluorescent blue light-emitting dopant. As the fluorescent red light emitting dopant, DCJTB or the like can be used. It is also preferable to use a charge transfer assisting dopant for the fluorescent light-emitting layer, and for example, NPD, TPD, Spiro-TAD, or the like can be used. The total doping concentration of the luminescent dopant and the charge transfer assisting dopant can be 1 to 30% by mass.

As the hole injection layer, CuPc, MTDATA, TiOPC, HAT-CN6, or the like can be used. Further, a hole transporting organic material doped with an acceptor may be used for the hole injection layer. Examples of the acceptor include MoO ₃ , V ₂ O ₅ and F4TCNQ.

  As the hole transport layer, TPD, NPD, TPAC, DTASi, a triarylamine compound, or the like can be used.

As the electron transport layer, BCP, TAZ, BAlq, Alq ₃ , OXD7, PBD, or the like can be used.

As an electron injection layer, in addition to fluorides, oxides, and carbonates of alkali metals and alkaline earth metals such as LiF, Li ₂ O, MgO, and Li ₂ CO ₃ , lithium, sodium, cesium, and calcium are used as organic layers. A layer doped with an alkali metal such as alkaline earth metal can be used.

  And the organic EL element A of the layer structure shown in FIG. 1 can be manufactured by forming and laminating the materials as described above in the appropriate order in the appropriate order. Lamination can usually be performed from the substrate 9 side. The film thickness of each electrode layer 2 can be about 10 to 300 nm, for example. The film forming method is not particularly limited, and examples thereof include a vacuum deposition method, a sputtering method, and a coating method.

  The electrode pad 4 can be formed by laminating metal materials. The electrode pad 4 may be formed before, during or after the lamination of each layer constituting the organic EL element A.

  After lamination of each layer constituting the organic EL element A, it is preferable to seal with a sealing substrate. Sealing can be performed by disposing an organic light emitting laminate between the substrate 9 and the sealing substrate. Thereby, deterioration due to moisture can be suppressed. A sealing region S is formed by sealing. At the time of sealing, sealing is performed so that the electrode pad 4 is disposed outside the sealing region S. At this time, a part of the electrode lead-out portion 10 may protrude from the sealing region S.

  After the organic EL element A is manufactured, the organic light emitting device can be manufactured by electrically connecting the organic EL element A to the power feeding mechanism 3 and the control unit 8 by the connection wiring 11. The organic light emitting device can be used as a planar lighting device.

[Embodiment 2]
FIG. 4 shows the organic EL element A and the organic light emitting device of the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The organic EL element A of Embodiment 2 is different from Embodiment 1 in the direction of current flow in each light emitting unit 1. The first end electrode layer 2a constitutes an anode. The second end electrode layer 2b constitutes a cathode. The first intermediate electrode layer 2p constitutes a cathode. The second intermediate electrode layer 2q constitutes the anode. Thus, also in the organic EL element A in which the anode and the cathode are replaced, the color matching can be effectively performed as in the first embodiment. The reason is the same as in the first embodiment. Moreover, the preferable aspect of the organic EL element A is the same as the content described in the first embodiment, and the reason is understood from the first embodiment.

[Embodiment 3]
FIG. 5 shows the organic EL element A and the organic light emitting device of the third embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The organic EL element A according to Embodiment 3 is different from Embodiment 1 in that a charge generation layer 5 is provided between the second light emitting unit 1b and the third light emitting unit 1c. The charge generation layer 5 is a layer that can inject holes to the cathode side and can inject electrons to the anode side. The charge generation layer 5 can be formed from, for example, the material of the electrode layer 2. The charge generation layer 5 is preferably composed of a material for the intermediate electrode layer.

  In the organic EL element A, the plurality of light emitting units 1 have at least one arrangement in which the charge generation layer 5 is sandwiched between the light emitting units 1 and the directions of the currents are the same as the arrangement of the adjacent light emitting units 1. It is a preferable embodiment. Thereby, the power feeding structure can be simplified, and color matching can be performed more easily.

  In the third embodiment, the first end electrode layer 2a constitutes a cathode. The second end electrode layer 2b constitutes a cathode. That is, the two end electrode layers are both composed of the cathode. The first intermediate electrode layer 2p constitutes an anode. Note that the charge generation layer 5 is disposed at the position of the second intermediate electrode layer 2q in Embodiment 1, and does not have the second intermediate electrode layer 2q. Therefore, there is one intermediate electrode layer.

  In Embodiment 3, as an arrangement of the light emitting units 1 adjacent to each other, there is one arrangement in which the electrode layer 2 is sandwiched between the light emitting units 1 and the current direction is opposite. This arrangement includes a first light emitting unit 1a and a second light emitting unit 1b.

  In the third embodiment, the arrangement of adjacent light emitting units 1 has one arrangement in which the charge generation layer 5 is sandwiched between the light emitting units 1 and the current direction is the same direction. This arrangement includes a second light emitting unit 1b and a third light emitting unit 1c. The direction of current in the second light emitting unit 1b is the same as the direction of current in the third light emitting unit 1c.

  The direction of current in the first light emitting unit 1a is opposite to the direction of current in the second light emitting unit 1b. Thus, even in the organic EL element A in which the charge generation layer 5 is arranged between the adjacent light emitting units 1, there is an arrangement of the adjacent light emitting units 1 in which the current directions are opposite. Therefore, it is possible to perform toning effectively as in the first embodiment. The reason is the same as in the first embodiment. Moreover, the preferable aspect of the organic EL element A is the same as the content described in the first embodiment, and the reason is understood from the first embodiment.

  The organic EL element A of Embodiment 3 has three electrode layers 2. One charge generation layer 5 is provided. When the number of light emitting units 1 is further increased (in the case of four or more), a plurality of charge generation layers 5 may be provided.

  In the third embodiment, two power feeding mechanisms 3 are provided. Since the number of power feeding mechanisms 3 is smaller than that in the first embodiment, the power feeding structure is simplified. In addition, light emission can be easily controlled.

  In the third embodiment, for example, the first light emitting unit 1a can be constituted by a fluorescent light emitting unit, and the second light emitting unit 1b and the third light emitting unit 1c can be constituted by phosphorescent light emitting units. Of course, the configuration of the light emitting unit 1 is not limited to this. The light extraction direction may be from the substrate 9 side or from the side opposite to the substrate 9.

  Also in the organic light emitting device of the third embodiment, the control unit 8 can perform the same preferable control as that described in the first embodiment. For example, it is possible to control to make the total current constant, or to make the current of the light emitting unit 1 having the highest visual sensitivity constant. Thereby, toning can be performed effectively.

[Embodiment 4]
FIG. 6 shows the organic EL element A and the organic light emitting device of the fourth embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. The fourth embodiment is a modification of the third embodiment. In the fourth embodiment, the position of the charge generation layer 5 is different from that of the third embodiment. The fourth embodiment is different from the third embodiment in that the two end electrodes function as anodes.

  In the organic EL element A of Embodiment 4, the charge generation layer 5 is provided between the first light emitting unit 1a and the second light emitting unit 1b. The charge generation layer 5 is a layer that can inject holes to the cathode side and can inject electrons to the anode side. The charge generation layer 5 can be formed from, for example, the material of the electrode layer 2. The charge generation layer 5 is preferably composed of a material for the intermediate electrode layer.

  In the organic EL element A, the plurality of light emitting units 1 have at least one arrangement in which the charge generation layer 5 is sandwiched between the light emitting units 1 and the directions of the currents are the same as the arrangement of the adjacent light emitting units 1. It is a preferable embodiment. Thereby, the power feeding structure can be simplified, and color matching can be performed more easily.

  In the fourth embodiment, the first end electrode layer 2a constitutes an anode. The second end electrode layer 2b constitutes an anode. That is, the two end electrode layers are both composed of the anode. There is one intermediate electrode layer. This intermediate electrode layer is defined as a first intermediate electrode layer 2p, and the first intermediate electrode layer 2p constitutes a cathode. The first intermediate electrode layer 2p is disposed at the position of the second intermediate electrode layer 2q in Embodiment 1, that is, between the second light emitting unit 1b and the third light emitting unit 1c. The charge generation layer 5 is disposed at the position of the first intermediate electrode layer 2p (position between the first light emitting unit 1a and the second light emitting unit 1b) in the first embodiment.

  In Embodiment 4, as an arrangement of the light emitting units 1 adjacent to each other, there is one arrangement in which the electrode layer 2 is sandwiched between the light emitting units 1 and the current direction is opposite. This arrangement includes a second light emitting unit 1b and a third light emitting unit 1c.

  In the fourth embodiment, as the arrangement of the light emitting units 1 adjacent to each other, there is one arrangement in which the charge generation layer 5 is sandwiched between these light emitting units 1 and the current direction is the same direction. This arrangement includes a first light emitting unit 1a and a second light emitting unit 1b. The direction of current in the first light emitting unit 1a and the direction of current in the second light emitting unit 1b are the same.

  The direction of the current in the second light emitting unit 1b is opposite to the direction of the current in the third light emitting unit 1c. Thus, even in the organic EL element A in which the charge generation layer 5 is arranged between the adjacent light emitting units 1, there is an arrangement of the adjacent light emitting units 1 in which the current directions are opposite. Therefore, it is possible to perform toning effectively as in the first embodiment. The reason is the same as in the first embodiment. Moreover, the preferable aspect of the organic EL element A is the same as the content described in the first embodiment, and the reason is understood from the first embodiment.

  The organic EL element A of Embodiment 4 has three electrode layers 2. One charge generation layer 5 is provided. When the number of light emitting units 1 is further increased (in the case of four or more), a plurality of charge generation layers 5 may be provided.

  In the fourth embodiment, two power feeding mechanisms 3 are provided. Since the number of power feeding mechanisms 3 is smaller than that in the first embodiment, the power feeding structure is simplified. In addition, light emission can be easily controlled.

  In the fourth embodiment, for example, the first light emitting unit 1a and the second light emitting unit 1b can be constituted by phosphorescent light emitting units, and the third light emitting unit 1c can be constituted by fluorescent light emitting units. Of course, the configuration of the light emitting unit 1 is not limited to this. The light extraction direction may be from the substrate 9 side or from the side opposite to the substrate 9.

  Also in the organic light emitting device of the fourth embodiment, the control unit 8 can perform the same preferable control as that described in the first embodiment. For example, it is possible to control to make the total current constant, or to make the current of the light emitting unit 1 having the highest visual sensitivity constant. Thereby, toning can be performed effectively.

[Embodiment 5]
FIG. 7 shows an organic EL element A and an organic light emitting device according to the fifth embodiment. The same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted.

  The organic EL element A of Embodiment 5 has two light emitting units 1. The two light emitting units 1 are composed of a first light emitting unit 1a and a second light emitting unit 1b. The two light emitting units 1 are disposed between the first end electrode layer 2a and the second end electrode layer 2b. A first intermediate electrode layer 2p is disposed as an intermediate electrode layer between the first light emitting unit 1a and the second light emitting unit 1b.

  The organic light emitting device has two power feeding mechanisms 3. Each electrode layer 2 is electrically connected to the power feeding mechanism 3 through the electrode pad 4.

  In the power feeding structure of the fifth embodiment, the first end electrode layer 2a functions as a cathode. The second end electrode layer 2b functions as a cathode. That is, the two end electrode layers are both composed of the cathode. There is one intermediate electrode layer. This intermediate electrode layer is defined as a first intermediate electrode layer 2p, and the first intermediate electrode layer 2p constitutes an anode.

  Also in the fifth embodiment, as the arrangement of the light emitting units 1 adjacent to each other, the electrode layer 2 is sandwiched between these light emitting units 1 and the direction of the current is reversed. In the fifth embodiment, the direction of current flow differs between the first light emitting unit 1a and the second light emitting unit 1b. Therefore, the amount of current can be adjusted for each light emitting unit 1, and the ratio of the light emission intensity can be changed. Therefore, the color generated as a whole can be changed, and toning can be performed. The specific reason is the same as in the first embodiment. Moreover, the preferable aspect of the organic EL element A is the same as the content described in the first embodiment, and the reason is understood from the first embodiment.

  Also in the organic light emitting device of the fifth embodiment, the control unit 8 can perform the same preferable control as that described in the first embodiment. For example, it is possible to control to make the total current constant, or to make the current of the light emitting unit 1 having high visibility constant. Thereby, toning can be performed effectively.

[Embodiment 6]
FIG. 8 shows the organic EL element A and the organic light emitting device of the sixth embodiment. The same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted.

  The organic EL element A of Embodiment 6 has two light emitting units 1. The two light emitting units 1 are composed of a first light emitting unit 1a and a second light emitting unit 1b. The two light emitting units 1 are disposed between the first end electrode layer 2a and the second end electrode layer 2b. A first intermediate electrode layer 2p is disposed as an intermediate electrode layer between the first light emitting unit 1a and the second light emitting unit 1b.

  The organic light emitting device has two power feeding mechanisms 3. Each electrode layer 2 is electrically connected to the power feeding mechanism 3 through the electrode pad 4.

  In the power feeding structure of the sixth embodiment, the first end electrode layer 2a functions as an anode. The second end electrode layer 2b functions as an anode. That is, the two end electrode layers are both composed of the anode. There is one intermediate electrode layer. This intermediate electrode layer is defined as a first intermediate electrode layer 2p, and the first intermediate electrode layer 2p constitutes a cathode.

  Also in Embodiment 6, as an arrangement of the light emitting units 1 adjacent to each other, the electrode layer 2 is sandwiched between the light emitting units 1 and the direction of the current is opposite. In the sixth embodiment, the direction of current flow is different between the first light emitting unit 1a and the second light emitting unit 1b. Therefore, the amount of current can be adjusted for each light emitting unit 1, and the ratio of the light emission intensity can be changed. Therefore, the color generated as a whole can be changed, and toning can be performed. The specific reason is the same as in the first embodiment. Moreover, the preferable aspect of the organic EL element A is the same as the content described in the first embodiment, and the reason is understood from the first embodiment.

  Also in the organic light emitting device of the sixth embodiment, the control unit 8 can perform the same preferable control as that described in the first embodiment. For example, it is possible to control to make the total current constant, or to make the current of the light emitting unit 1 having high visibility constant. Thereby, toning can be performed effectively.

[Embodiment 7]
FIG. 9 shows an organic EL element A and an organic light emitting device according to the seventh embodiment. The same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. The seventh embodiment is a modification of the fifth embodiment. The seventh embodiment is different from the fifth embodiment in that the thin metal film 6 is provided. Other than that may be the same structure.

  In the power feeding structure of the seventh embodiment, the first end electrode layer 2a and the second end electrode layer 2b function as cathodes. The first intermediate electrode layer 2p constitutes an anode. The direction in which current flows is different between the first light emitting unit 1a and the second light emitting unit 1b. Therefore, the amount of current can be adjusted for each light emitting unit 1, and the ratio of the light emission intensity can be changed. Therefore, the color generated as a whole can be changed, and toning can be performed. The specific reason is the same as in the first embodiment. Moreover, the preferable aspect of the organic EL element A is the same as the content described in the first embodiment, and the reason is understood from the first embodiment.

  In the organic EL element A, when two electrode layers 2 provided at both ends of the plurality of light emitting units 1 among the three or more electrode layers 2 form a cathode, the two electrode layers 2 are arranged on the light extraction side. The electrode layer 2 to be formed preferably has a metal thin film 6. The electrode layer 2 disposed on the light extraction side functions as an electrode having optical transparency. When the electrode having optical transparency is formed of a cathode, the function of injecting electrons may be weakened. For example, when the electrode is made of a metal oxide such as ITO, there is a possibility that the electron injection property may be lowered even if the hole injection property is not hindered. Therefore, the metal thin film 6 is provided on the electrode layer 2 on the light extraction side. Then, since the metal thin film 6 usually has a higher function of injecting electrons than the material constituting the light-transmitting electrode, it compensates for the electron injection property of the transparent electrode material, and serves as the cathode of the electrode layer 2. Function is improved. Therefore, the light emission efficiency can be further increased.

  The metal thin film 6 is preferably light transmissive. Therefore, it is preferable that the thickness of the metal thin film 6 is thin, for example, it can be set to 100 nm or less, more preferably 50 nm or less, further preferably 30 nm or less, and further preferably 20 nm or less. . The thickness of the metal thin film 6 is preferably thin, but if it is too thin, the layer may not be stably formed. For example, the thickness of the metal thin film 6 can be 1 nm or more.

  In the seventh embodiment, the two end electrode layers are both composed of cathodes. The light extraction side is the substrate 9 side. Therefore, the first end electrode layer 2 a that is the end electrode layer disposed on the light extraction side has the metal thin film 6. The metal thin film 6 is preferably provided on the light emitting unit 1 side of the electrode layer 2 (in this embodiment, the first light emitting unit 1a side of the first end electrode layer 2a). When the metal thin film 6 is in contact with the most cathode side layer in the light emitting unit 1, the electron injection property can be efficiently increased.

  By the way, the 2nd end electrode layer 2b arrange | positioned on the opposite side to the light extraction side can be comprised as a light reflective electrode. In that case, more light can be extracted outside by the reflection function. Further, the second end electrode layer 2b may have a laminated structure of a light transmissive electrode material layer and a light reflective electrode material layer. Even in that case, more light can be extracted outside by the reflection function.

  Also in the organic light emitting device of the seventh embodiment, the control unit 8 can perform the same preferable control as that described in the first embodiment. For example, it is possible to control to make the total current constant, or to make the current of the light emitting unit 1 having high visibility constant. Thereby, toning can be performed effectively.

[Embodiment 8]
FIG. 10 shows an organic EL element A and an organic light emitting device according to the eighth embodiment. The same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. The ninth embodiment is a modification of the sixth embodiment. The eighth embodiment is different from the sixth embodiment in that the light reflecting mechanism 7 is provided. Other than that may be the same structure.

  In the power feeding structure of the eighth embodiment, the first end electrode layer 2a and the second end electrode layer 2b function as anodes. The first intermediate electrode layer 2p constitutes a cathode. The direction in which current flows is different between the first light emitting unit 1a and the second light emitting unit 1b. Therefore, the amount of current can be adjusted for each light emitting unit 1, and the ratio of the light emission intensity can be changed. Therefore, the color generated as a whole can be changed, and toning can be performed. The specific reason is the same as in the first embodiment. Moreover, the preferable aspect of the organic EL element A is the same as the content described in the first embodiment, and the reason is understood from the first embodiment.

  In the organic EL element A, when two electrode layers 2 provided at both ends of the plurality of light emitting units 1 among the three or more electrode layers 2 constitute an anode, it is preferable that the light reflection mechanism 7 is provided. In a preferred embodiment, the light reflecting mechanism 7 can be provided on the side opposite to the light extraction side than the end electrode layer disposed on the side opposite to the light extraction side of the two end electrode layers. Since the light reflecting mechanism 7 can reflect the light and direct the light to the light extraction side, more light can be extracted to the outside.

  In the eighth embodiment, the light reflection mechanism 7 is constituted by a light reflector 7a. The light reflector 7a can be made of an appropriate reflective material. As the reflective material, a metal film, an inorganic material, a dielectric multilayer film, or the like can be used. The light reflector 7a may be a conductive material. When the light reflector 7a is a conductive material, the conductivity of the electrode layer 2 can be assisted if the light reflector 7a is in contact with the electrode layer 2. Of course, the light reflector 7a may be made of an insulating material.

  The aspect in which the light reflector 7a is provided is preferably employed when the end electrode layer (second end electrode layer 2b) on the side opposite to the light extraction side is light transmissive.

  In the eighth embodiment, the two end electrode layers are both composed of the anode. The light extraction side is the substrate 9 side. Therefore, the light reflector 7a is provided as the light reflecting mechanism 7 on the side opposite to the substrate 9 of the second end electrode layer 2b that is the end electrode layer opposite to the light extraction side. If the electrode layer 2 is transparent, light will be emitted to the side opposite to the light extraction side, and there is a possibility of wasted light emission. Therefore, by providing the light reflecting mechanism 7, more light can be extracted outside.

  The light reflector 7a may be provided in contact with the end electrode layer (second end electrode layer 2b) on the side opposite to the light extraction side or may not be provided in contact. For example, the organic EL element A is normally sealed by a sealing substrate, but the light reflector 7a may be provided on the surface of the sealing substrate. Even in that case, more light can be extracted outside by reflecting the light.

  The light reflecting mechanism 7 is not limited to the structure constituted by the light reflector 7a. It is another preferable aspect that the light reflecting mechanism 7 is provided on the end electrode layer (second end electrode layer 2b) itself opposite to the light extraction side. In this case, if the electrode layer 2 is configured as a light reflective electrode, the electrode layer 2 having the light reflecting mechanism 7 can be configured. When the electrode layer 2 itself has light reflectivity, the light extraction property can be easily improved. The light-reflective electrode layer 2 can be formed using, for example, a material such as Al or Ag or an alloy material containing any of these materials.

  Also in the organic light emitting device of the eighth embodiment, the control unit 8 can perform the same preferable control as that described in the first embodiment. For example, it is possible to control to make the total current constant, or to make the current of the light emitting unit 1 having high visibility constant. Thereby, toning can be performed effectively.

DESCRIPTION OF SYMBOLS 1 Light emission unit 1a 1st light emission unit 1b 2nd light emission unit 1c 3rd light emission unit 2 Electrode layer 2a 1st end electrode layer 2b 2nd end electrode layer 2p 1st intermediate electrode layer 2q 2nd intermediate electrode layer 3 Feed mechanism 3a Power supply 4 Electrode Pad 5 Charge Generation Layer 6 Metal Thin Film 7 Light Reflection Mechanism 7a Light Reflector 8 Control Part 9 Substrate 10 Electrode Lead Part 11 Connection Wiring

Claims (9)

An organic electroluminescence device comprising a plurality of light emitting units and three or more electrode layers,
The three or more electrode layers are configured to be connectable to two or more power feeding mechanisms,
The plurality of light emitting units, as the arrangement of the adjacent light emitting units, has one or more arrangements in which the electrode layer is sandwiched between these light emitting units and the direction of current is opposite. Organic electroluminescence device. The three or more electrode layers are electrically connected to each electrode pad,
2. The organic electroluminescence device according to claim 1, wherein each of the electrode pads is arranged close to at least one end. As the electrode layer sandwiched between adjacent light emitting units, the electrode layer functioning as an anode,
The electrode layer functioning as the anode is characterized in that a difference between a work function value of the electrode layer and an ionization potential value between adjacent layers on both sides is smaller than 1.0 eV in absolute value. The organic electroluminescence device according to claim 1 or 2. As the electrode layer sandwiched between adjacent light emitting units, the electrode layer functioning as a cathode,
The electrode layer functioning as the cathode is characterized in that a difference between a work function value of the electrode layer and an electron affinity value between adjacent layers on both sides is smaller than 1.5 eV in absolute value. The organic electroluminescent element according to any one of claims 1 to 3.   The plurality of light emitting units, as the arrangement of the adjacent light emitting units, has one or more arrangements in which a charge generation layer is sandwiched between these light emitting units and the direction of current is the same direction. The organic electroluminescent element of any one of Claims 1-4. Of the three or more electrode layers, two electrode layers provided at both ends of the plurality of light emitting units constitute a cathode,
The organic electroluminescence element according to claim 1, wherein the electrode layer disposed on the light extraction side of the two electrode layers has a metal thin film. Of the three or more electrode layers, two electrode layers provided at both ends of the plurality of light emitting units constitute an anode,
Of the two electrode layers, a light reflection mechanism is provided on the electrode layer disposed on the opposite side of the light extraction side or on the opposite side of the electrode layer from the light extraction side. The organic electroluminescent element according to any one of claims 1 to 6. The organic electroluminescence element according to claim 1, the two or more power feeding mechanisms, and a control unit that controls a current flowing from the two or more power feeding mechanisms,
The organic light emitting device according to claim 1, wherein the control unit is configured to perform control to make the total current constant. The organic electroluminescence element according to claim 1, the two or more power feeding mechanisms, and a control unit that controls a current flowing from the two or more power feeding mechanisms,
The said control part is comprised so that the electric current of the said light emission unit with the largest visibility among several said light emission units may be controlled, It is comprised, The organic light-emitting device characterized by the above-mentioned.

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