An organic electroluminescence device and a light emitting apparatus

Abstract

The application discloses an organic electroluminescent device and a light-emitting device. The organic electroluminescent device comprises a distributed Bragg reflector structure, a light-transmitting electrode, an organic light-emitting layer and a reflective electrode; the distributed Bragg reflector structure comprises a first distributed Bragg reflector layer or a second distributed Bragg reflector layer and a third distributed Bragg reflector layer; the first distributed Bragg reflector layer comprises a plurality of first sub-layers, the thickness of the even layers in the first sub-layers is l / 4n1, and the thickness of the odd layers is l / 4n2; the second distributed Bragg reflector layer is used for enhancing light of a first wave band, and the third distributed Bragg reflector layer is used for enhancing light of a second wave band. The organic electroluminescent device of the application emits light of two wavelengths, and the light has high intensity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic light-emitting, and in particular to an organic electroluminescent device and a light-emitting apparatus. BACKGROUND

[0002] The existing organic light-emitting material usually has a relatively wide half-peak width, and includes light in a certain wavelength range in the emission spectrum, but has a peak wavelength. For example, the dye emitting infrared light has a relatively low overall radiation efficiency due to the energy gap effect. The existing organic light-emitting device cannot meet the above requirements. SUMMARY

[0003] The present application provides an organic electroluminescent device and a light-emitting apparatus, so that the light of two wavelengths emitted by the organic electroluminescent device has a relatively high intensity.

[0004] According to an aspect of the present application, an organic electroluminescent device is provided, comprising:

[0005] a distributed Bragg reflection structure, a light-transmitting electrode, an organic light-emitting layer and a reflective electrode which are sequentially stacked;

[0006] The organic light-emitting layer is configured to emit light in a first wavelength band and light in a second wavelength band; the distributed Bragg reflection structure comprises a first distributed Bragg reflection layer, or the distributed Bragg reflection structure comprises a second distributed Bragg reflection layer and a third distributed Bragg reflection layer.

[0007] The first distributed Bragg reflection layer comprises a plurality of first sub-layers which are sequentially stacked, and the refractive index of the even layers in the plurality of first sub-layers is greater than the refractive index of the odd layers in the plurality of first sub-layers along a direction from the light-transmitting electrode to the distributed Bragg reflection structure; the thickness of the even layers in the first sub-layers is λ1 / 4n1, λ1 is a peak wavelength of the first wavelength band, and n1 is the refractive index of the even layers in the first sub-layers; the thickness of the odd layers in the first sub-layers is λ2 / 4n2, λ2 is a peak wavelength of the second wavelength band, and n2 is the refractive index of the odd layers in the first sub-layers.

[0008] The second distributed Bragg reflection layer is configured to enhance the light in the first wavelength band, and the third distributed Bragg reflection layer is configured to enhance the light in the second wavelength band.

[0009] Optionally, the second distributed Bragg reflection layer comprises a plurality of second sub-layers which are sequentially stacked, and the refractive index of the even layers in the plurality of second sub-layers is greater than the refractive index of the odd layers in the plurality of second sub-layers along a direction from the light-transmitting electrode to the distributed Bragg reflection structure; the thickness of each second sub-layer is λ1 / 4n3, wherein n3 is the refractive index of the second sub-layer.

[0010] The third distributed Bragg reflection layer comprises a plurality of third sub-layers arranged in sequence, and the refractive index of even layers in the plurality of third sub-layers is greater than the refractive index of odd layers in the plurality of third sub-layers along a direction in which the light-transmitting electrode is directed to the distributed Bragg reflection structure; and the thickness of each third sub-layer is λ2 / 4n4, wherein n4 is the refractive index of the third sub-layer.

[0011] Optionally, the organic electroluminescent device further comprises:

[0012] a connecting layer arranged between the second distributed Bragg reflection layer and the third distributed Bragg reflection layer;

[0013] The connecting layer is configured to reduce interference between the light of the first wave band and the light of the second wave band.

[0014] Optionally, the second distributed Bragg reflection layer is arranged on a side of the third distributed Bragg reflection layer away from the light-transmitting electrode, and the thickness of the connecting layer is λ1 / 2n5; wherein n5 is the refractive index of the connecting layer.

[0015] The third distributed Bragg reflection layer is arranged on a side of the second distributed Bragg reflection layer away from the light-transmitting electrode, and the thickness of the connecting layer is λ2 / 2n5.

[0016] Optionally, the material of the connecting layer comprises at least one of silicon oxide, titanium oxide and silicon nitride.

[0017] Optionally, the number of the first sub-layers is even and greater than or equal to 4.

[0018] The number of the second sub-layers is even and greater than or equal to 4.

[0019] The number of the third sub-layers is even and greater than or equal to 4.

[0020] Optionally, the refractive index of all even layers in the plurality of first sub-layers is the same, and the refractive index of all odd layers in the plurality of first sub-layers is the same.

[0021] The refractive index of all even layers in the plurality of second sub-layers is the same, and the refractive index of all odd layers in the plurality of second sub-layers is the same.

[0022] The refractive index of all even layers in the plurality of third sub-layers is the same, and the refractive index of all odd layers in the plurality of third sub-layers is the same.

[0023] Optionally, the material of all even layers in the plurality of first sub-layers is the same, and the material of all odd layers in the plurality of first sub-layers is the same.

[0024] The material of all even layers in the plurality of second sub-layers is the same, and the material of all odd layers in the plurality of second sub-layers is the same.

[0025] The material of all even layers in the plurality of third sub-layers is the same, and the material of all odd layers in the plurality of third sub-layers is the same.

[0026] Optionally, the organic light-emitting layer has a higher emission efficiency for emitting light of the second waveband than for emitting light of the first waveband.

[0027] The first waveband is a red waveband, and the second waveband is an infrared waveband.

[0028] Optionally, the organic electroluminescent device further comprises:

[0029] The first functional layer is arranged between the transparent electrode and the organic light-emitting layer, and the second functional layer is arranged between the reflective electrode and the organic light-emitting layer.

[0030] When the transparent electrode is an anode and the reflective electrode is a cathode, the first functional layer comprises at least one of a hole injection layer, a hole transport layer and an electron blocking layer, and the second functional layer comprises at least one of an electron injection layer, an electron transport layer and a hole blocking layer.

[0031] When the reflective electrode is an anode and the transparent electrode is a cathode, the second functional layer comprises at least one of a hole injection layer, a hole transport layer and an electron blocking layer, and the first functional layer comprises at least one of an electron injection layer, an electron transport layer and a hole blocking layer.

[0032] According to another aspect of the present application, there is provided a light-emitting device comprising a plurality of organic electroluminescent devices according to any embodiment of the present application.

[0033] The organic electroluminescent device provided by the embodiment of the present application is characterized in that a distributed Bragg reflector structure is arranged on the side of the light-transmitting electrode; the distributed Bragg reflector structure comprises a first distributed Bragg reflector layer, or the distributed Bragg reflector structure comprises a second distributed Bragg reflector layer and a third distributed Bragg reflector layer; the first distributed Bragg reflector layer comprises a plurality of first sub-layers arranged in sequence, the refractive index of the even layers in the plurality of first sub-layers is greater than the refractive index of the odd layers, the thickness of the even layers in the first sub-layers is λ1 / 4n1, the thickness of the odd layers in the first sub-layers is λ2 / 4n2, and the first distributed Bragg reflector layer can simultaneously enhance the light of the first waveband and the light of the second waveband; the second distributed Bragg reflector layer is used for enhancing the light of the first waveband, and the third distributed Bragg reflector layer is used for enhancing the light of the second waveband. After the light of the first waveband and the light of the second waveband emitted by the organic light-emitting layer irradiate on the distributed Bragg reflector structure, the distributed Bragg reflector structure enhances the light of the first waveband and the light of the second waveband, and the enhanced light of the first waveband and the light of the second waveband are emitted from the distributed Bragg reflector structure, so that the light of the two wavelengths emitted by the organic electroluminescent device has high intensity.

[0034] It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the present application or to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0036] Figure 1 is a schematic diagram of an organic electroluminescent device provided by an embodiment of the present application.

[0037] Figure 2 is a schematic diagram of another organic electroluminescent device provided by an embodiment of the present application.

[0038] Figure 3 is a schematic diagram of an organic electroluminescent device provided by an embodiment of the present application.

[0039] Figure 4 is a luminescence spectrum diagram of the organic electroluminescent device of the embodiment of the present application.

[0040] Figure 5 is a schematic diagram of an organic electroluminescent device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0042] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0043] The embodiment of the present application provides an organic electroluminescent device, Figure 1 is a schematic diagram of an organic electroluminescent device provided by the embodiment of the present application, Figure 2 is a schematic diagram of another organic electroluminescent device provided by the embodiment of the present application, referring to Figure 1 and Figure 2 The organic electroluminescent device comprises:

[0044] The distributed Bragg reflection structure 10, the light-transmitting electrode 20, the organic light-emitting layer 30 and the reflective electrode 40 are sequentially stacked;

[0045] The organic light-emitting layer 30 is used for emitting light of a first wave band and light of a second wave band; the distributed Bragg reflection structure 10 comprises a first distributed Bragg reflection layer 11, or the distributed Bragg reflection structure 10 comprises a second distributed Bragg reflection layer 12 and a third distributed Bragg reflection layer 13;

[0046] The first distributed Bragg reflection layer 11 comprises a plurality of first sub-layers 110 arranged in sequence, and the refractive index of the even layers of the plurality of first sub-layers 110 is greater than the refractive index of the odd layers in the direction of the distributed Bragg reflection structure 10 directed by the light-transmitting electrode 20; the thickness of the even layers of the first sub-layers 110 is λ1 / 4n1, λ1 is the peak wavelength of the first waveband, and n1 is the refractive index of the even layers of the first sub-layers 110; the thickness of the odd layers of the first sub-layers 110 is λ2 / 4n2, λ2 is the peak wavelength of the second waveband, and n2 is the refractive index of the odd layers of the first sub-layers 110;

[0047] The second distributed Bragg reflection layer 12 is used for enhancing the light of the first waveband, and the third distributed Bragg reflection layer 13 is used for enhancing the light of the second waveband.

[0048] The one of the light-transmitting electrode 20 and the reflecting electrode 40 is an anode, and the other is a cathode. The first waveband can be an infrared waveband, and the second waveband can be a red waveband. The organic light-emitting layer 30 can adopt a red material with a certain intensity in the infrared waveband. That is, the organic light-emitting layer 30 can emit red light and infrared light. The light-transmitting electrode 20 adopts a transparent metal oxide material such as ITO. The reflecting electrode 40 can adopt a metal material such as aluminum or magnesium. The light emitted by the organic light-emitting layer 30 is emitted to the distributed Bragg reflection structure 10 by the light-transmitting electrode 20.

[0049] Reference Figure 1 The refractive index of the even layers of the plurality of first sub-layers 110 is greater than the refractive index of the odd layers in the direction of the distributed Bragg reflection structure 10 directed by the light-transmitting electrode 20, the first sub-layer 110 adjacent to the light-transmitting electrode 20 is the first first sub-layer 110, and the first, second, third, and so on first sub-layers 110 are arranged in sequence in the direction away from the light-transmitting electrode 20. The odd layers 111 (low refractive index layers) and the even layers 112 (high refractive index layers) of the first sub-layers are alternately arranged in the direction of the distributed Bragg reflection structure 10 directed by the light-transmitting electrode 20.

[0050] The distributed Bragg reflector (DBR) is a reflector used in waveguide. When light passes through different media, it will be reflected at the interface. The reflectivity is related to the refractive index between the media. By stacking different refractive index films periodically, when light passes through these different refractive index films, the reflected light from each layer will constructively interfere due to the change in phase angle, and then combine together to get strong reflected light, i.e. DBR can enhance light. The advantage of DBR is its high reflectivity. When the electromagnetic wave falls within the energy gap of the material, it cannot penetrate and the reflectivity can be very high. DBR performs well in improving the brightness of organic electroluminescent devices. Compared with the traditional metal mirror, DBR avoids the problem of metal absorbing light energy. The optical thickness of each layer in DBR is 1 / 4 of the center reflection wavelength. By adjusting the thickness of each layer in DBR, the position of the energy gap can be accurately adjusted to accurately control the light.

[0051] Reference Figure 1 When the distributed Bragg reflector structure 10 includes the first distributed Bragg reflector layer 11, the first distributed Bragg reflector layer 11 includes a plurality of first sub-layers 110 arranged in sequence, the refractive index of the even layers in the plurality of first sub-layers 110 is greater than the refractive index of the odd layers, and the first distributed Bragg reflector layer 11 is a DBR. By setting the thickness of the even layers in the first sub-layers 110 as λ1 / 4n1 and the thickness of the odd layers in the first sub-layers 110 as λ2 / 4n2, after the first waveband light and the second waveband light emitted by the organic light-emitting layer 30 irradiate the distributed Bragg reflector structure 10, the distributed Bragg reflector structure 10 enhances the first waveband light and the second waveband light, and the enhanced first waveband light and the second waveband light are emitted from the distributed Bragg reflector structure 10.

[0052] Reference Figure 2 When the distributed Bragg reflector structure 10 includes the second distributed Bragg reflector layer 12 and the third distributed Bragg reflector layer 13, the second distributed Bragg reflector layer 12 is a DBR, and the third distributed Bragg reflector layer 13 is a DBR. The second distributed Bragg reflector layer 12 enhances the first waveband light, and the third distributed Bragg reflector layer 13 enhances the second waveband light.

[0053] The organic electroluminescent device of the embodiment of the present application is characterized in that a distributed Bragg reflector 10 is arranged on the side of the light-transmitting electrode 20; the distributed Bragg reflector 10 comprises a first distributed Bragg reflector layer 11, or the distributed Bragg reflector 10 comprises a second distributed Bragg reflector layer 12 and a third distributed Bragg reflector layer 13; the first distributed Bragg reflector layer 11 comprises a plurality of first sub-layers 110 arranged in sequence, the refractive index of the even layers of the plurality of first sub-layers 110 is greater than the refractive index of the odd layers, the thickness of the even layers of the first sub-layers 110 is λ1 / 4n1, the thickness of the odd layers of the first sub-layers 110 is λ2 / 4n2, and the first distributed Bragg reflector layer 11 can simultaneously enhance the light of the first waveband and the light of the second waveband; the second distributed Bragg reflector layer 12 is used for enhancing the light of the first waveband, and the third distributed Bragg reflector layer 13 is used for enhancing the light of the second waveband. After the light of the first waveband and the light of the second waveband emitted by the organic light-emitting layer 30 irradiate on the distributed Bragg reflector 10, the distributed Bragg reflector 10 enhances the light of the first waveband and the light of the second waveband, and the enhanced light of the first waveband and the light of the second waveband are emitted from the distributed Bragg reflector 10, so that the light of the two wavelengths emitted by the organic electroluminescent device has high intensity.

[0054] On the basis of the above implementation, optionally, with reference to Figure 2 The second distributed Bragg reflector layer 12 comprises a plurality of second sub-layers 120 arranged in sequence, and the refractive index of the even layers of the plurality of second sub-layers 120 is greater than the refractive index of the odd layers along the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflector 10; the thickness of each second sub-layer 120 is λ1 / 4n3, wherein n3 is the refractive index of the second sub-layer 120;

[0055] The third distributed Bragg reflector layer 13 comprises a plurality of third sub-layers 130 arranged in sequence, and the refractive index of the even layers of the plurality of third sub-layers 130 is greater than the refractive index of the odd layers along the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflector 10; the thickness of each third sub-layer 130 is λ2 / 4n4, wherein n4 is the refractive index of the third sub-layer 130.

[0056] Optionally, with reference to Figure 2In the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflection structure 10, the refractive index of the even layers in the plurality of second sub-layers 120 is greater than the refractive index of the odd layers, and the second sub-layer 120 closest to the light-transmitting electrode 20 is the first second sub-layer 120, and the first second sub-layer 120, the second second sub-layer 120, the third second sub-layer 120, and so on are arranged in turn in the direction away from the light-transmitting electrode 20. In the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflection structure 10, the second sub-layer odd layers 121 (low refractive index layers) and the second sub-layer even layers 122 (high refractive index layers) are arranged alternately in turn.

[0057] In the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflection structure 10, the refractive index of the even layers in the plurality of third sub-layers 130 is greater than the refractive index of the odd layers, and the third sub-layer 130 closest to the light-transmitting electrode 20 is the first third sub-layer 130, and the first third sub-layer 130, the second third sub-layer 130, the third third sub-layer 130, and so on are arranged in turn in the direction away from the light-transmitting electrode 20. In the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflection structure 10, the third sub-layer odd layers 131 (low refractive index layers) and the third sub-layer even layers 132 (high refractive index layers) are arranged alternately in turn.

[0058] With reference to Figure 2 When the distributed Bragg reflection structure 10 includes the second distributed Bragg reflection layer 12 and the third distributed Bragg reflection layer 13, the second distributed Bragg reflection layer 12 includes a plurality of second sub-layers 120 arranged in turn, and the refractive index of the even layers in the plurality of second sub-layers 120 is greater than the refractive index of the odd layers, and the second distributed Bragg reflection layer 12 is a DBR. The thickness of each second sub-layer 120 is λ1 / 4n3, n3 is the refractive index of the second sub-layer 120, and for example, the thickness of the first second sub-layer 120 is λ1 / 4 divided by the refractive index of the first second sub-layer 120, and the thickness of the second second sub-layer 120 is λ1 / 4 divided by the refractive index of the second second sub-layer 120. By setting the thickness of each second sub-layer 120 to be λ1 / 4n3, the second distributed Bragg reflection layer 12 can enhance the first waveband of light emitted by the organic light-emitting layer 30 after the first waveband of light is incident on the distributed Bragg reflection structure 10, and the enhanced first waveband of light is emitted from the distributed Bragg reflection structure 10.

[0059] The third DBR layer 13 includes a plurality of third sub-layers 130 stacked in sequence, and the refractive index of the even layers is greater than the refractive index of the odd layers. The third DBR layer 13 is a DBR. The thickness of each third sub-layer 130 is λ2 / 4n4, where n4 is the refractive index of the third sub-layer 130. For example, the thickness of the first third sub-layer 130 is λ2 / 4 divided by the refractive index of the first third sub-layer 130, and the thickness of the second third sub-layer 130 is λ2 / 4 divided by the refractive index of the second third sub-layer 130. By setting the thickness of each third sub-layer 130 to be λ2 / 4n4, the third DBR layer 13 can enhance the second band of light emitted by the organic light-emitting layer 30 after the second band of light is irradiated to the DBR structure 10, and the enhanced second band of light is emitted from the DBR structure 10. Therefore, when the DBR structure 10 includes the second DBR layer 12 and the third DBR layer 13, the DBR structure 10 enhances the first band of light and the second band of light, and the enhanced first band of light and the enhanced second band of light are emitted from the DBR structure 10.

[0060] In addition, the second DBR layer 12 can be located on the side of the third DBR layer 13 adjacent to the transparent electrode 20, or on the side of the third DBR layer 13 away from the transparent electrode 20.

[0061] The organic electroluminescent device provided by the embodiment of the present application is characterized in that a distributed Bragg reflector 10 is arranged on the side of the light-transmitting electrode 20; the distributed Bragg reflector 10 comprises a first distributed Bragg reflector layer 11, or the distributed Bragg reflector 10 comprises a second distributed Bragg reflector layer 12 and a third distributed Bragg reflector layer 13; the first distributed Bragg reflector layer 11 comprises a plurality of first sub-layers 110 arranged in sequence, the refractive index of the even layers in the plurality of first sub-layers 110 is greater than the refractive index of the odd layers, the thickness of the even layers in the first sub-layers 110 is λ1 / 4n1, and the thickness of the odd layers in the first sub-layers 110 is λ2 / 4n2; the first distributed Bragg reflector layer 11 can simultaneously enhance the light of the first waveband and the light of the second waveband; the second distributed Bragg reflector layer 12 comprises a plurality of second sub-layers 120 arranged in sequence, the refractive index of the even layers in the plurality of second sub-layers 120 is greater than the refractive index of the odd layers; the thickness of each second sub-layer 120 is λ1 / 4n3; the second distributed Bragg reflector layer 12 is used for enhancing the light of the first waveband; the third distributed Bragg reflector layer 13 comprises a plurality of third sub-layers 130 arranged in sequence, the refractive index of the even layers in the plurality of third sub-layers 130 is greater than the refractive index of the odd layers, and the thickness of each third sub-layer 130 is λ2 / 4n4; the third distributed Bragg reflector layer 13 is used for enhancing the light of the second waveband; after the light of the first waveband and the light of the second waveband emitted by the organic light-emitting layer 30 irradiate on the distributed Bragg reflector 10, the distributed Bragg reflector 10 enhances the light of the first waveband and the light of the second waveband, and the enhanced light of the first waveband and the light of the second waveband are emitted from the distributed Bragg reflector 10, so that the light of the two wavelengths emitted by the organic electroluminescent device has high intensity.

[0062] On the basis of the above-mentioned embodiment, optionally, with reference to Figure 2 The organic electroluminescent device further comprises a connecting layer 50 arranged between the second distributed Bragg reflector layer 12 and the third distributed Bragg reflector layer 13; the connecting layer 50 is used for reducing the interference between the light of the first waveband and the light of the second waveband.

[0063] Specifically, by arranging the connecting layer 50, the light interference between the second distributed Bragg reflector layer 12 and the third distributed Bragg reflector layer 13 can be avoided, and the light-emitting efficiency of the organic electroluminescent device is improved.

[0064] Figure 3 is a schematic diagram of the organic electroluminescent device provided by the embodiment of the present application, on the basis of the above-mentioned embodiment, optionally, with reference to Figure 2 The second distributed Bragg reflector layer 12 is arranged on the side of the third distributed Bragg reflector layer 13 away from the light-transmitting electrode 20, and the thickness of the connecting layer 50 is λ1 / 2n5; wherein n5 is the refractive index of the connecting layer; with reference toFigure 3 The third distributed Bragg reflector layer 13 is arranged on the side of the second distributed Bragg reflector layer 12 away from the light-transmitting electrode 20, and the thickness of the connecting layer 50 is λ2 / 2n5.

[0065] Specifically, by arranging the connecting layer 50 with an optical thickness (optical thickness = actual thickness * refractive index) of 1 / 2 of a preset wavelength between the second distributed Bragg reflector layer 12 and the third distributed Bragg reflector layer 13, the mutual interference between the spectra can be prevented, and the normal spectral shape can be ensured, wherein the preset wavelength is the center reflection wavelength corresponding to the reflection layer adjacent to the light-emitting side in the second distributed Bragg reflector layer 12 and the third distributed Bragg reflector layer 13, the center reflection wavelength of the second distributed Bragg reflector layer 12 is λ1, and the center reflection wavelength of the third distributed Bragg reflector layer 13 is λ2.

[0066] On the basis of the above embodiment, optionally, the material of the connecting layer 50 includes at least one of silicon oxide, titanium oxide, and silicon nitride.

[0067] Specifically, the silicon oxide, titanium oxide, and silicon nitride materials have low prices and mature manufacturing processes, and the use of the silicon oxide, titanium oxide, and silicon nitride for the connecting layer 50 can reduce the process and material costs.

[0068] On the basis of the above embodiment, optionally, with reference to Figure 1 and Figure 2 The number of the first sub-layers 110 is an even number and greater than or equal to 4, the number of the second sub-layers 120 is an even number and greater than or equal to 4, and the number of the third sub-layers 130 is an even number and greater than or equal to 4.

[0069] Specifically, the number of the first sub-layers 110 is an even number and greater than or equal to 4, that is, the first distributed Bragg reflector layer 11 includes 4 pairs or more of high-refractive-index layers and low-refractive-index layers, and each pair of high-refractive-index layers and low-refractive-index layers includes two first sub-layers 110. In this way, the first distributed Bragg reflector layer 11 can enhance the light of the first waveband and the second waveband to a greater extent, and improve the light-emitting intensity.

[0070] The number of the second sub-layers 120 is an even number and greater than or equal to 4, that is, the second distributed Bragg reflector layer 12 includes 4 pairs or more of high-refractive-index layers and low-refractive-index layers, and each pair of high-refractive-index layers and low-refractive-index layers includes two second sub-layers 120. In this way, the second distributed Bragg reflector layer 12 can enhance the light of the first waveband to a greater extent, and improve the light-emitting intensity.

[0071] The number of the third sub-layers 130 is even and greater than or equal to 4, that is, the third DBR layer 13 includes 4 pairs or more of high refractive index layers and low refractive index layers, and each pair of the high refractive index layer and the low refractive index layer includes two third sub-layers 130. In this way, the third DBR layer 13 can enhance the light of the third wavelength band to a greater extent, thereby improving the light intensity.

[0072] On the basis of the above-mentioned embodiments, optionally, the refractive index of all even layers in the plurality of first sub-layers 110 is the same, and the refractive index of all odd layers in the plurality of first sub-layers 110 is the same; the refractive index of all even layers in the plurality of second sub-layers 120 is the same, and the refractive index of all odd layers in the plurality of second sub-layers 120 is the same; the refractive index of all even layers in the plurality of third sub-layers 130 is the same, and the refractive index of all odd layers in the plurality of third sub-layers 130 is the same.

[0073] Specifically, the refractive index of all even layers in the plurality of first sub-layers 110 is the same, and the refractive index of all odd layers in the plurality of first sub-layers 110 is the same, so that the thickness of all even layers in the plurality of first sub-layers 110 is the same, and the thickness of all odd layers in the plurality of first sub-layers 110 is the same, thereby reducing the difficulty of the manufacturing process of the first DBR layer 11.

[0074] The refractive index of all even layers in the plurality of second sub-layers 120 is the same, and the refractive index of all odd layers in the plurality of second sub-layers 120 is the same, so that the thickness of all even layers in the plurality of second sub-layers 120 is the same, and the thickness of all odd layers in the plurality of second sub-layers 120 is the same, thereby reducing the difficulty of the manufacturing process of the second DBR layer 12.

[0075] The refractive index of all even layers in the plurality of third sub-layers 130 is the same, and the refractive index of all odd layers in the plurality of third sub-layers 130 is the same, so that the thickness of all even layers in the plurality of third sub-layers 130 is the same, and the thickness of all odd layers in the plurality of third sub-layers 130 is the same, thereby reducing the difficulty of the manufacturing process of the third DBR layer 13.

[0076] On the basis of the above-mentioned embodiments, optionally, the material of all even layers in the plurality of first sub-layers 110 is the same, and the material of all odd layers in the plurality of first sub-layers 110 is the same; the material of all even layers in the plurality of second sub-layers 120 is the same, and the material of all odd layers in the plurality of second sub-layers 120 is the same; the material of all even layers in the plurality of third sub-layers 130 is the same, and the material of all odd layers in the plurality of third sub-layers 130 is the same.

[0077] Specifically, the materials of all even layers in the plurality of first sub-layers 110 are the same, and the materials of all odd layers in the plurality of first sub-layers 110 are the same, so that all even layers in the plurality of first sub-layers 110 can be prepared by the same process, and all odd layers in the plurality of first sub-layers 110 can be prepared by the same process, thereby reducing the process cost.

[0078] The materials of all even layers in the plurality of second sub-layers 120 are the same, and the materials of all odd layers in the plurality of second sub-layers 120 are the same, so that all even layers in the plurality of second sub-layers 120 can be prepared by the same process, and all odd layers in the plurality of second sub-layers 120 can be prepared by the same process, thereby reducing the process cost.

[0079] The materials of all even layers in the plurality of third sub-layers 130 are the same, and the materials of all odd layers in the plurality of third sub-layers 130 are the same, so that all even layers in the plurality of third sub-layers 130 can be prepared by the same process, and all odd layers in the plurality of third sub-layers 130 can be prepared by the same process, thereby reducing the process cost.

[0080] On the basis of the above-mentioned embodiments, optionally, the emission efficiency of the organic light-emitting layer 30 emitting light of the second waveband is higher than the emission efficiency of the organic light-emitting layer 30 emitting light of the first waveband.

[0081] Specifically, the emission efficiency of the organic light-emitting layer 30 emitting light of the first waveband is low, and the optical thickness (optical thickness = actual thickness * refractive index) of the even layers with high refractive index in the first distributed Bragg reflector 11 is set to 1 / 4 of the peak wavelength of the first waveband, so that the first distributed Bragg reflector 11 has a strong enhancement effect on the light of the first waveband, and the organic electroluminescent device can emit light of the first waveband with strong light intensity. At the same time, the optical thickness of the odd layers in the first distributed Bragg reflector 11 is 1 / 4 of the peak wavelength of the second waveband, and the first distributed Bragg reflector 11 has an enhancement effect on the light of the second waveband, so that the organic electroluminescent device can emit light of the first waveband and light of the second waveband.

[0082] On the basis of the above-mentioned embodiments, optionally, the first waveband is a red waveband; and the second waveband is an infrared waveband.

[0083] Specifically, photo biomodulation therapy (PBMT), also known as low level laser therapy (LLLT), refers to the use of a light flux of 1–10 J / cm 2 , an irradiance of 1-90 mW / cm 2Red light and infrared light with a wavelength in the range of 600-1000 nm are used for treatment. Clinical studies show that such light can stimulate epidermal stem cells in the hair follicle to promote hair growth; it can also promote wound healing, tissue repair and anti-inflammatory treatment. Due to the energy gap effect, the efficiency of existing organic electroluminescent devices in the infrared light-emitting band is limited, and it is difficult to do high. Figure 4 is a luminescence spectrum diagram of an organic electroluminescent device according to an embodiment of the present application, referring to Figure 4 , the embodiment sets the organic electroluminescent device to include a distributed Bragg reflector structure, which can enhance the light intensity of infrared light, so that the organic electroluminescent device can emit red light and infrared light with relatively strong intensity at the same time.

[0084] Figure 5 is a schematic diagram of an organic electroluminescent device according to an embodiment of the present application, and on the basis of the above embodiment, optionally, referring to Figure 5 , the organic electroluminescent device further comprises:

[0085] a first functional layer 60 and a second functional layer 70; the first functional layer 60 is arranged between the light-transmitting electrode 20 and the organic light-emitting layer 30, and the second functional layer 70 is arranged between the reflective electrode 40 and the organic light-emitting layer 30;

[0086] When the light-transmitting electrode 20 is an anode and the reflective electrode 40 is a cathode, the first functional layer 60 includes at least one of a hole injection layer, a hole transport layer and an electron blocking layer, and the second functional layer 70 includes at least one of an electron injection layer, an electron transport layer and a hole blocking layer;

[0087] When the reflective electrode 40 is an anode and the light-transmitting electrode 20 is a cathode, the second functional layer 70 includes at least one of a hole injection layer, a hole transport layer and an electron blocking layer, and the first functional layer 60 includes at least one of an electron injection layer, an electron transport layer and a hole blocking layer.

[0088] Among them, the hole injection layer is arranged on the side of the hole transport layer adjacent to the anode, the electron blocking layer is arranged on the side of the hole transport layer adjacent to the organic light-emitting layer 30, the hole injection layer is used to improve the hole injection efficiency, the hole transport layer is used to improve the hole transport rate, and the electron blocking layer is used to block the electron. The electron injection layer is arranged on the side of the electron transport layer adjacent to the cathode, and the hole blocking layer is arranged on the side of the electron transport layer adjacent to the organic light-emitting layer 30. The electron injection layer is used to improve the electron injection efficiency, the electron transport layer is used to improve the electron transport rate, and the hole blocking layer is used to block the hole. By arranging the first functional layer 60 and the second functional layer 70, the light-emitting efficiency of the organic electroluminescent device can be improved, and the light intensity of the first waveband and the second waveband can be improved.

[0089] The embodiment of the present application further provides a light-emitting device comprising a plurality of the organic electroluminescent devices according to any of the embodiments of the present application. The light-emitting device can be a light medical device or other light-emitting device.

[0090] It should be understood that the various forms of flow shown above can be used to reorder, add, or delete steps. For example, the steps described in the present application can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which are not limited herein.

[0091] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An organic electroluminescent device, characterized by comprising: Comprise: A distributed Bragg reflector structure, a light-transmitting electrode, an organic light-emitting layer and a reflective electrode are sequentially stacked; The organic light-emitting layer is used for emitting light of a first waveband and light of a second waveband; the distributed Bragg reflector structure comprises a first distributed Bragg reflector layer, or the distributed Bragg reflector structure comprises a second distributed Bragg reflector layer and a third distributed Bragg reflector layer; the first distributed Bragg reflector layer is used for simultaneously enhancing the light of the first waveband and the light of the second waveband; the second distributed Bragg reflector layer is used for enhancing the light of the first waveband, and the third distributed Bragg reflector layer is used for enhancing the light of the second waveband; the enhanced light of the first waveband and the light of the second waveband are emitted by the distributed Bragg reflector structure; The first distributed Bragg reflector layer comprises a plurality of first sub-layers which are sequentially stacked; along a direction in which the light-transmitting electrode points to the distributed Bragg reflector structure, the refractive index of an even layer in the plurality of first sub-layers is greater than the refractive index of an odd layer; the thickness of the even layer in the first sub-layers is λ1 / 4n1, λ1 is a peak wavelength of the first waveband, and n1 is the refractive index of the even layer in the first sub-layers; the thickness of the odd layer in the first sub-layers is λ2 / 4n2, λ2 is a peak wavelength of the second waveband, and n2 is the refractive index of the odd layer in the first sub-layers; The second distributed Bragg reflector layer comprises a plurality of second sub-layers which are sequentially stacked; along a direction in which the light-transmitting electrode points to the distributed Bragg reflector structure, the refractive index of an even layer in the plurality of second sub-layers is greater than the refractive index of an odd layer; the thickness of each second sub-layer is λ1 / 4n3, wherein n3 is the refractive index of the second sub-layer; The third distributed Bragg reflector layer comprises a plurality of third sub-layers which are sequentially stacked; along a direction in which the light-transmitting electrode points to the distributed Bragg reflector structure, the refractive index of an even layer in the plurality of third sub-layers is greater than the refractive index of an odd layer; the thickness of each third sub-layer is λ2 / 4n4, wherein n4 is the refractive index of the third sub-layer.

2. The organic electroluminescent device according to claim 1, wherein Further comprise: A connecting layer arranged between the second distributed Bragg reflector layer and the third distributed Bragg reflector layer; The connecting layer is used for reducing interference between the light of the first waveband and the light of the second waveband.

3. The organic electroluminescent device according to claim 2, characterized in that: The second distributed Bragg reflector layer is arranged on a side of the third distributed Bragg reflector layer away from the light-transmitting electrode, and the thickness of the connecting layer is λ1 / 2n5; wherein n5 is the refractive index of the connecting layer; Or, the third distributed Bragg reflector layer is arranged on a side of the second distributed Bragg reflector layer away from the light-transmitting electrode, and the thickness of the connecting layer is λ2 / 2n5.

4. The organic electroluminescent device according to claim 2, characterized in that: The material of the connecting layer comprises at least one of silicon oxide, titanium oxide and silicon nitride.

5. The organic electroluminescent device according to claim 1, characterized in that: The number of first sub-layers is even and greater than or equal to 4. The number of the second sub-layer is even, and greater than or equal to 4; The number of third sub-layers is even, and greater than or equal to 4.

6. The organic electroluminescent device according to claim 1, characterized in that: All even-numbered layers in the plurality of first sublayers have the same refractive index, and all odd-numbered layers in the plurality of first sublayers have the same refractive index. All even-numbered layers in multiple second sublayers have the same refractive index, and all odd-numbered layers in multiple second sublayers have the same refractive index. All even-numbered layers in the plurality of third sublayers have the same refractive index, and all odd-numbered layers in the plurality of third sublayers have the same refractive index.

7. The organic electroluminescent device according to claim 6, characterized in that: The material of all even-numbered layers in multiple first sublayers is the same, and the material of all odd-numbered layers in multiple first sublayers is the same; The material of all even-numbered layers in multiple second sub-layers is the same, and the material of all odd-numbered layers in multiple second sub-layers is the same; All even-numbered layers in the plurality of third sublayers are made of the same material, and all odd-numbered layers in the plurality of third sublayers are made of the same material.

8. The organic electroluminescent device according to claim 1, characterized in that: The organic light-emitting layer emits light in the second band with higher efficiency than it emits light in the first band. The first band is the red light band; the second band is the infrared band. The organic electroluminescent device further includes: A first functional layer and a second functional layer; the first functional layer is disposed between the light-transmitting electrode and the organic light-emitting layer, and the second functional layer is disposed between the reflective electrode and the organic light-emitting layer; When the phototransmitting electrode is the anode and the reflective electrode is the cathode, the first functional layer includes at least one of a hole injection layer, a hole transport layer and an electron blocking layer, and the second functional layer includes at least one of an electron injection layer, an electron transport layer and a hole blocking layer. When the reflective electrode is the anode and the phototransmitting electrode is the cathode, the second functional layer includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, and the first functional layer includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer.

9. A light-emitting device, characterized in that, It includes the organic electroluminescent devices according to any one of claims 1-8.

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