Organic light-emitting device and light-emitting device

Abstract

The invention discloses an organic light-emitting device and a light-emitting device. The organic light-emitting device comprises a distributed Bragg reflection structure, a light-transmitting electrode, an organic light-emitting layer and a reflection electrode, the distributed Bragg reflection structure comprises a first distributed Bragg reflection layer or comprises a second distributed Bragg reflection layer and a third distributed Bragg reflection layer; the first distributed Bragg reflection layer comprises a plurality of first sub-layers, the thickness of even-numbered layers in the first sub-layers is lambda1 / 4n1, and the thickness of odd-numbered layers in the first sub-layers is lambda2 / 4n2; the second distributed Bragg reflection layer is used for enhancing the light of the first wave band, and the third distributed Bragg reflection layer is used for enhancing the light of the second wave band. The light with two wavelengths emitted by the organic light-emitting device disclosed by the invention has relatively high intensity.

Description

Technical Field

[0001] The present invention relates to the field of organic light emitting technology, and in particular to an organic electroluminescent device and a light emitting apparatus. Background Art

[0002] Existing organic light-emitting materials usually have a wide half-peak width, and the emission spectrum includes light in a certain wavelength range, but has a peak wavelength. For example, due to the energy gap effect, the overall radiation efficiency of dyes that emit infrared light is low. Existing organic light-emitting devices cannot meet the above requirements. Summary of the invention

[0003] The present invention provides an organic electroluminescent device and a light-emitting apparatus, so that the light of two wavelengths emitted by the organic electroluminescent device both have higher intensity.

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

[0005] A distributed Bragg reflection structure, a light-transmitting electrode, an organic light-emitting layer and a reflection electrode are stacked in sequence;

[0006] Wherein, the organic light-emitting layer is used to emit light of a first wavelength band and light of a second wavelength band; the distributed Bragg reflection structure includes a first distributed Bragg reflection layer, or the distributed Bragg reflection structure includes a second distributed Bragg reflection layer and a third distributed Bragg reflection layer;

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

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

[0009] Optionally, the second distributed Bragg reflector layer comprises a plurality of second sub-layers stacked in sequence, and the refractive index of the even-numbered layers in the plurality of second sub-layers is greater than the refractive index of the odd-numbered layers along the direction of the light-transmitting electrode pointing to the distributed Bragg reflector 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 includes a plurality of third sub-layers stacked in sequence, along the direction of the distributed Bragg reflection structure pointing to the light-transmitting electrode, and the refractive index of the even-numbered layers in the plurality of third sub-layers is greater than the refractive index of the odd-numbered layers; the thickness of each of the third sub-layers is λ2 / 4n4, wherein n4 is the refractive index of the third sub-layer.

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

[0012] A connection layer disposed between the second distributed Bragg reflector layer and the third distributed Bragg reflector layer;

[0013] The connection layer is used to reduce interference between the light in the first wavelength band and the light in the second wavelength band.

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

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

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

[0017] Optionally, the number of first sublayers is an even number and is greater than or equal to 4;

[0018] The number of the second sublayers is an even number and is greater than or equal to 4;

[0019] The number of the third sublayers is an even number and is greater than or equal to 4.

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

[0021] The refractive indexes of all even-numbered layers in the plurality of second sub-layers are the same, and the refractive indexes of all odd-numbered layers in the plurality of second sub-layers are the same;

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

[0023] Optionally, the materials of all even-numbered layers in the plurality of first sub-layers are the same, and the materials of all odd-numbered layers in the plurality of first sub-layers are the same;

[0024] All even-numbered layers in the plurality of second sub-layers are made of the same material, and all odd-numbered layers in the plurality of second sub-layers are made of the same material;

[0025] The materials of all even-numbered layers in the plurality of third sub-layers are the same, and the materials of all odd-numbered layers in the plurality of third sub-layers are the same.

[0026] Optionally, the emission efficiency of the organic light-emitting layer in emitting the light in the second wavelength band is higher than the emission efficiency in emitting the light in the first wavelength band;

[0027] The first band is the red light band; the second band is the infrared band.

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

[0029] 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;

[0030] When the light-transmitting electrode is an anode and the reflective electrode is a 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;

[0031] When the reflective electrode is an anode and the light-transmitting electrode is a 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.

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

[0033] The organic electroluminescent device of the embodiment of the present invention is provided with a distributed Bragg reflection structure on one side of the light-transmitting electrode; the distributed Bragg reflection structure includes a first distributed Bragg reflection layer, or the distributed Bragg reflection structure includes a second distributed Bragg reflection layer and a third distributed Bragg reflection layer; the first distributed Bragg reflection layer includes a plurality of first sub-layers stacked in sequence, the refractive index of the even-numbered layers in the plurality of first sub-layers is greater than the refractive index of the odd-numbered layers, the thickness of the even-numbered layers in the first sub-layers is λ1 / 4n1, and the thickness of the odd-numbered layers in the first sub-layers is λ2 / 4n2, and the first distributed Bragg reflection layer can enhance the light of the first band and the second band at the same time; the second distributed Bragg reflection layer is used to enhance the light of the first band, and the third distributed Bragg reflection layer is used to enhance the light of the second band. After the light of the first band and the light of the second band emitted by the organic light-emitting layer are irradiated to the distributed Bragg reflection structure, the distributed Bragg reflection structure enhances the light of the first band and the light of the second band, and the enhanced light of the first band and the light of the second band are emitted by the distributed Bragg reflection structure, so that the light of the two wavelengths emitted by the organic electroluminescent device has a high intensity.

[0034] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

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

[0038] Figure 3 It is a schematic diagram of an organic electroluminescent device provided in an embodiment of the present invention.

[0039] Figure 4 It is a light emission spectrum diagram of the organic electroluminescent device according to an embodiment of the present invention.

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

[0041] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

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

[0043] An embodiment of the present invention provides an organic electroluminescent device, Figure 1 is a schematic diagram of an organic electroluminescent device provided by an embodiment of the present invention, Figure 2 is a schematic diagram of another organic electroluminescent device provided by an embodiment of the present invention, with reference to Figure 1 and Figure 2 , the organic electroluminescent device comprises:

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

[0045] The organic light emitting layer 30 is used to emit light of a first wavelength band and light of a second wavelength band; the distributed Bragg reflection structure 10 includes a first distributed Bragg reflection layer 11, or the distributed Bragg reflection structure 10 includes a second distributed Bragg reflection layer 12 and a third distributed Bragg reflection layer 13;

[0046] The first distributed Bragg reflector 11 comprises a plurality of first sub-layers 110 stacked in sequence, and along the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflector structure 10, the refractive index of the even-numbered layers in the plurality of first sub-layers 110 is greater than the refractive index of the odd-numbered layers; the thickness of the even-numbered layers in the first sub-layer 110 is λ1 / 4n1, λ1 is the peak wavelength of the first band, and n1 is the refractive index of the even-numbered layers in the first sub-layer 110; the thickness of the odd-numbered layers in the first sub-layer 110 is λ2 / 4n2, λ2 is the peak wavelength of the second band, and n2 is the refractive index of the odd-numbered layers in the first sub-layer 110;

[0047] The second distributed Bragg reflector 12 is used to enhance the light in the first wavelength band, and the third distributed Bragg reflector 13 is used to enhance the light in the second wavelength band.

[0048] Among them, one of the transparent electrode 20 and the reflective electrode 40 is an anode and the other is a cathode. The first band can be an infrared band, and the second band can be a red band. The organic light-emitting layer 30 can use a red light material whose luminous spectrum has a certain intensity in the infrared band. That is, the organic light-emitting layer 30 can emit red light and infrared light. The transparent electrode 20 uses a transparent metal oxide material such as ITO. The reflective electrode 40 can use a metal material such as aluminum or magnesium. The light emitted by the organic light-emitting layer 30 is emitted from the transparent electrode 20 to the distributed Bragg reflection structure 10.

[0049] refer to Figure 1 , along the direction from the transparent electrode 20 to the distributed Bragg reflector structure 10, the refractive index of the even-numbered layers in the plurality of first sub-layers 110 is greater than the refractive index of the odd-numbered layers, and the first sub-layer 110 adjacent to the transparent electrode 20 is the first first sub-layer 110, and so on, along the direction away from the transparent electrode 20, the first first sub-layer 110, the second first sub-layer 110, the third first sub-layer 110, ... are arranged in sequence. Along the direction from the transparent electrode 20 to the distributed Bragg reflector structure 10, the first sub-layer odd-numbered layers 111 (low refractive index layers) and the first sub-layer even-numbered layers 112 (high refractive index layers) are arranged alternately in sequence.

[0050] Distributed Bragg reflector (DBR) is a reflector used in waveguides. When light passes through different media, it will reflect at the interface. The reflectivity is related to the refractive index between the media. By stacking thin films with different refractive indices interactively and periodically, when light passes through these thin films with different refractive indices, the light reflected from each layer will constructively interfere due to the change in phase angle, and then combine with each other to obtain strong reflected light, that is, DBR can enhance the light. The advantage of DBR lies in its high reflectivity. When electromagnetic waves fall into the energy gap range of the material, the reflectivity can reach a very high level because they cannot penetrate. DBR performs well in improving the brightness of organic electroluminescent devices. Compared with traditional metal reflectors, DBR avoids the problem of metal absorbing light energy. The optical thickness of each layer in DBR is 1 / 4 of the central reflection wavelength. By adjusting the thickness of each layer in DBR, the position of the energy gap can be accurately adjusted to achieve precise control of light.

[0051] refer to 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 stacked in sequence, the refractive index of the even-numbered layers in the plurality of first sub-layers 110 is greater than the refractive index of the odd-numbered layers, and the first distributed Bragg reflector layer 11 is a DBR. By setting the thickness of the even-numbered layers in the first sub-layer 110 to λ1 / 4n1 and the thickness of the odd-numbered layers in the first sub-layer 110 to λ2 / 4n2, after the light of the first wavelength band and the light of the second wavelength band emitted by the organic light-emitting layer 30 are irradiated to the distributed Bragg reflector structure 10, the distributed Bragg reflector structure 10 enhances the light of the first wavelength band and the light of the second wavelength band, and the enhanced light of the first wavelength band and the light of the second wavelength band are emitted from the distributed Bragg reflector structure 10.

[0052] refer to Figure 2 When the distributed Bragg reflector structure 10 includes a second distributed Bragg reflector layer 12 and a 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 light of the first wavelength band, and the third distributed Bragg reflector layer 13 enhances the light of the second wavelength band.

[0053] The organic electroluminescent device of the embodiment of the present invention is provided with a distributed Bragg reflection structure 10 on one side of a light-transmitting electrode 20; the distributed Bragg reflection structure 10 includes a first distributed Bragg reflection layer 11, or the distributed Bragg reflection structure 10 includes a second distributed Bragg reflection layer 12 and a third distributed Bragg reflection layer 13; the first distributed Bragg reflection layer 11 includes a plurality of first sub-layers 110 stacked in sequence, the refractive index of the even-numbered layers in the plurality of first sub-layers 110 is greater than the refractive index of the odd-numbered layers, the thickness of the even-numbered layers in the first sub-layers 110 is λ1 / 4n1, the thickness of the odd-numbered layers in the first sub-layers 110 is λ2 / 4n2, and the first distributed Bragg reflection layer 11 can simultaneously enhance the light of the first wavelength band and the second wavelength band; the second distributed Bragg reflection layer 12 is used to enhance the light of the first wavelength band, and the third distributed Bragg reflection layer 13 is used to enhance the light of the second wavelength band. After the light of the first wavelength band and the light of the second wavelength band emitted by the organic light-emitting layer 30 are irradiated to the distributed Bragg reflection structure 10, the distributed Bragg reflection structure 10 enhances the light of the first wavelength band and the light of the second wavelength band. The enhanced light of the first wavelength band and the light of the second wavelength band are emitted by the distributed Bragg reflection structure 10, so that the two wavelengths of light emitted by the organic electroluminescent device have higher intensities.

[0054] Based on the above implementation, optionally, refer to Figure 2 The second distributed Bragg reflector 12 includes a plurality of second sub-layers 120 stacked in sequence, along the direction of the light-transmitting electrode 20 pointing to the distributed Bragg reflector structure 10, and the refractive index of the even-numbered layers in the plurality of second sub-layers 120 is greater than the refractive index of the odd-numbered layers; the thickness of each second sub-layer 120 is λ1 / 4n3, where n3 is the refractive index of the second sub-layer 120;

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

[0056] Among them, reference Figure 2, along the direction from the transparent electrode 20 to the distributed Bragg reflector structure 10, the refractive index of the even-numbered layers in the plurality of second sub-layers 120 is greater than that of the odd-numbered layers, and the second sub-layer 120 closest to the transparent electrode 20 is the first second sub-layer 120, and so on, along the direction away from the transparent electrode 20, the first second sub-layer 120, the second second sub-layer 120, the third second sub-layer 120, ... are arranged in sequence. Along the direction from the transparent electrode 20 to the distributed Bragg reflector structure 10, the second sub-layer odd-numbered layers 121 (low refractive index layers) and the second sub-layer even-numbered layers 122 (high refractive index layers) are arranged alternately in sequence.

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

[0058] refer to 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 includes a plurality of second sub-layers 120 stacked in sequence, the refractive index of the even-numbered layers in the plurality of second sub-layers 120 is greater than the refractive index of the odd-numbered layers, and the second distributed Bragg reflector layer 12 is a DBR. The thickness of each second sub-layer 120 is λ1 / 4n3, where n3 is the refractive index of the second sub-layer 120. 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 λ1 / 4n3, after the light of the first wavelength band emitted by the organic light-emitting layer 30 is irradiated to the distributed Bragg reflector structure 10, the second distributed Bragg reflector layer 12 can enhance the light of the first wavelength band, and the enhanced light of the first wavelength band is emitted from the distributed Bragg reflector structure 10.

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

[0060] In addition, the second distributed Bragg reflective layer 12 may be located on a side of the third distributed Bragg reflective layer 13 adjacent to the light-transmitting electrode 20 , or may be located on a side of the third distributed Bragg reflective layer 13 away from the light-transmitting electrode 20 .

[0061] The organic electroluminescent device of the embodiment of the present invention is provided with a distributed Bragg reflection structure 10 on one side of the light-transmitting electrode 20; the distributed Bragg reflection structure 10 includes a first distributed Bragg reflection layer 11, or the distributed Bragg reflection structure 10 includes a second distributed Bragg reflection layer 12 and a third distributed Bragg reflection layer 13; the first distributed Bragg reflection layer 11 includes a plurality of first sub-layers 110 stacked in sequence, the refractive index of the even-numbered layers in the plurality of first sub-layers 110 is greater than the refractive index of the odd-numbered layers, the thickness of the even-numbered layers in the first sub-layers 110 is λ1 / 4n1, and the thickness of the odd-numbered layers in the first sub-layers 110 is λ2 / 4n2. The first distributed Bragg reflection layer 11 can enhance the light of the first wavelength band and the second wavelength band at the same time. The second distributed Bragg reflection layer 12 includes a plurality of second sub-layers 120 stacked in sequence, the refractive index of the even-numbered layers in the plurality of second sub-layers 120 is greater than the refractive index of the odd-numbered layers; the thickness of each second sub-layer 120 is λ1 / 4n3; the second distributed Bragg reflection layer 12 is used to enhance the light of the first wavelength band. The third distributed Bragg reflector 13 includes a plurality of third sub-layers 130 stacked in sequence, wherein the refractive index of the even-numbered layers in the plurality of third sub-layers 130 is greater than the refractive index of the odd-numbered layers, and the thickness of each third sub-layer 130 is λ2 / 4n4; the third distributed Bragg reflector 13 is used to enhance the light in the second wavelength band. After the light in the first wavelength band and the light in the second wavelength band emitted by the organic light-emitting layer 30 are irradiated to the distributed Bragg reflector structure 10, the distributed Bragg reflector structure 10 enhances the light in the first wavelength band and the light in the second wavelength band, and the enhanced light in the first wavelength band and the light in the second wavelength band are emitted from the distributed Bragg reflector structure 10, so that the light of the two wavelengths emitted by the organic electroluminescent device has a high intensity.

[0062] Based on the above embodiment, optionally, refer to Figure 2 The organic electroluminescent device further includes: a connection layer 50 disposed between the second distributed Bragg reflective layer 12 and the third distributed Bragg reflective layer 13; the connection layer 50 is used to reduce interference between the light of the first wavelength band and the light of the second wavelength band.

[0063] Specifically, by providing the connection layer 50 , mutual interference of light between the second distributed Bragg reflective layer 12 and the third distributed Bragg reflective layer 13 can be avoided, thereby improving the light extraction efficiency of the organic electronic light emitting device.

[0064] Figure 3 is a schematic diagram of an organic electroluminescent device provided in an embodiment of the present invention. Based on the above embodiment, optionally, reference Figure 2 , the second distributed Bragg reflection layer 12 is arranged on the side of the third distributed Bragg reflection layer 13 away from the transparent electrode 20, and the thickness of the connecting layer 50 is λ1 / 2n5; wherein n5 is the refractive index of the connecting layer; Figure 3 The third distributed Bragg reflector 13 is disposed on a side of the second distributed Bragg reflector 12 away from the light-transmitting electrode 20 , and the thickness of the connecting layer 50 is λ2 / 2n5.

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

[0066] Based on the above embodiment, optionally, the material of the connection layer 50 includes at least one of silicon oxide, titanium oxide and silicon nitride.

[0067] Specifically, silicon oxide, titanium oxide and silicon nitride are relatively low in price and have mature manufacturing processes. The connection layer 50 uses silicon oxide, titanium oxide and silicon nitride, which can reduce process and material costs.

[0068] Based on the above embodiment, optionally, refer to Figure 1 and Figure 2 , the number of the first sub-layers 110 is an even number and is greater than or equal to 4; the number of the second sub-layers 120 is an even number and is greater than or equal to 4; the number of the third sub-layers 130 is an even number and is greater than or equal to 4.

[0069] Specifically, the number of the first sublayers 110 is an even number and is greater than or equal to 4, that is, the first distributed Bragg reflector 11 includes 4 or more pairs 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 sublayers 110. In this way, the first distributed Bragg reflector 11 can enhance the light in the first wavelength band and the second wavelength band to a greater extent, thereby improving the light output intensity.

[0070] The number of the second sublayers 120 is an even number and is greater than or equal to 4, that is, the second distributed Bragg reflector 12 includes 4 or more pairs 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 sublayers 120. In this way, the second distributed Bragg reflector 12 can enhance the light in the first wavelength band to a greater extent and improve the light output intensity.

[0071] The number of the third sublayers 130 is an even number and is greater than or equal to 4, that is, the third distributed Bragg reflector 13 includes 4 or more pairs 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 third sublayers 130. In this way, the third distributed Bragg reflector 13 can enhance the light in the third wavelength band to a greater extent and improve the light output intensity.

[0072] Based on the above embodiments, optionally, all even-numbered layers in the multiple first sublayers 110 have the same refractive index, and all odd-numbered layers in the multiple first sublayers 110 have the same refractive index; all even-numbered layers in the multiple second sublayers 120 have the same refractive index, and all odd-numbered layers in the multiple second sublayers 120 have the same refractive index; all even-numbered layers in the multiple third sublayers 130 have the same refractive index, and all odd-numbered layers in the multiple third sublayers 130 have the same refractive index.

[0073] Specifically, the refractive index of all even-numbered layers in the multiple first sublayers 110 is the same, and the refractive index of all odd-numbered layers in the multiple first sublayers 110 is the same, so that the thickness of all even-numbered layers in the multiple first sublayers 110 is the same, and the thickness of all odd-numbered layers in the multiple first sublayers 110 is the same, thereby reducing the difficulty of the manufacturing process of the first Bragg distributed reflection layer 11.

[0074] The refractive index of all even-numbered layers in the multiple second sublayers 120 is the same, and the refractive index of all odd-numbered layers in the multiple second sublayers 120 is the same, so that the thickness of all even-numbered layers in the multiple second sublayers 120 is the same, and the thickness of all odd-numbered layers in the multiple second sublayers 120 is the same, reducing the difficulty of the manufacturing process of the second Bragg distributed reflection layer 12.

[0075] The refractive index of all even-numbered layers in the multiple third sublayers 130 is the same, and the refractive index of all odd-numbered layers in the multiple third sublayers 130 is the same, so that the thickness of all even-numbered layers in the multiple third sublayers 130 is the same, and the thickness of all odd-numbered layers in the multiple third sublayers 130 is the same, reducing the difficulty of the manufacturing process of the third Bragg distributed reflection layer 13.

[0076] Based on the above embodiments, optionally, the materials of all even-numbered layers in the multiple first sublayers 110 are the same, and the materials of all odd-numbered layers in the multiple first sublayers 110 are the same; the materials of all even-numbered layers in the multiple second sublayers 120 are the same, and the materials of all odd-numbered layers in the multiple second sublayers 120 are the same; the materials of all even-numbered layers in the multiple third sublayers 130 are the same, and the materials of all odd-numbered layers in the multiple third sublayers 130 are the same.

[0077] Specifically, the materials of all the even-numbered layers in the multiple first sublayers 110 are the same, and the materials of all the odd-numbered layers in the multiple first sublayers 110 are the same, so that all the even-numbered layers in the multiple first sublayers 110 can be prepared using the same process, and all the odd-numbered layers in the multiple first sublayers 110 can be prepared using the same process, thereby reducing process costs.

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

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

[0080] On the basis of the above embodiment, optionally, the emission efficiency of the organic light-emitting layer 30 for emitting light in the second wavelength band is higher than the emission efficiency for emitting light in the first wavelength band.

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

[0082] Based on the above embodiment, optionally, the first waveband is a red light waveband; and the second waveband is an infrared waveband.

[0083] Specifically, photobiomodulation therapy (PBMT), also known as low-level laser therapy (LLLT), refers to the use of a laser with a light flux of 1–10 J / cm 2 The irradiance is 1-90mW / cm 2The treatment is carried out with red and infrared light with a wavelength in the range of 600-1000nm. Clinical studies have shown that such light can stimulate the epidermal stem cells in the hair follicles to promote hair growth; it can also promote wound healing, tissue repair and anti-inflammatory treatment. However, due to the energy gap effect, the efficiency of existing organic electroluminescent devices in the infrared emission band is limited and it is difficult to increase it. Figure 4 is a light emitting spectrum diagram of an organic electroluminescent device according to an embodiment of the present invention, with reference to Figure 4 In this embodiment, the organic electroluminescent device includes a distributed Bragg reflection structure, which can enhance the light intensity of infrared light, so that the organic electrode light-emitting device can simultaneously emit strong red light and infrared light.

[0084] Figure 5 is a schematic diagram of an organic electroluminescent device provided in an embodiment of the present invention. Based on the above embodiment, optionally, reference 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 disposed between the light-transmitting electrode 20 and the organic light-emitting layer 30, and the second functional layer 70 is disposed 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 transparent 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 electrons. The electron injection layer is arranged on the side of the electron transport layer adjacent to the cathode, 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 holes. By arranging the first functional layer 60 and the second functional layer 70, the luminous efficiency of the organic electroluminescent device can be improved, and the light output intensity of the light in the first band and the second band can be improved.

[0089] The embodiment of the present invention further provides a light-emitting device, comprising a plurality of organic electroluminescent devices according to any embodiment of the present invention, wherein the light-emitting device may be a photomedical device or other light-emitting device.

[0090] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0091] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An organic electroluminescent device, characterized in that: include: A distributed Bragg reflection structure, a light-transmitting electrode, an organic light-emitting layer and a reflection electrode are stacked in sequence; Wherein, the organic light-emitting layer is used to emit light of a first wavelength band and light of a second wavelength band; the distributed Bragg reflection structure includes a first distributed Bragg reflection layer, or the distributed Bragg reflection structure includes a second distributed Bragg reflection layer and a third distributed Bragg reflection layer; The first distributed Bragg reflector layer comprises a plurality of first sub-layers stacked in sequence, and along the direction of the light-transmitting electrode pointing to the distributed Bragg reflector structure, the refractive index of the even-numbered layers in the plurality of first sub-layers is greater than the refractive index of the odd-numbered layers; the thickness of the even-numbered layers in the first sub-layer is λ1 / 4n1, λ1 is the peak wavelength of the first band, and n1 is the refractive index of the even-numbered layers in the first sub-layer; the thickness of the odd-numbered layers in the first sub-layer is λ2 / 4n2, λ2 is the peak wavelength of the second band, and n2 is the refractive index of the odd-numbered layers in the first sub-layer; The second distributed Bragg reflector layer is used to enhance light in a first wavelength band, and the third distributed Bragg reflector layer is used to enhance light in a second wavelength band.

2. The organic electroluminescent device according to claim 1, characterized in that: The second distributed Bragg reflector layer comprises a plurality of second sub-layers stacked in sequence, along the direction of the light-transmitting electrode pointing to the distributed Bragg reflector structure, the refractive index of the even-numbered layers in the plurality of second sub-layers being greater than the refractive index of the odd-numbered layers; 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 reflection layer includes a plurality of third sub-layers stacked in sequence, along the direction of the distributed Bragg reflection structure pointing to the light-transmitting electrode, and the refractive index of the even-numbered layers in the plurality of third sub-layers is greater than the refractive index of the odd-numbered layers; the thickness of each of the third sub-layers is λ2 / 4n4, wherein n4 is the refractive index of the third sub-layer.

3. The organic electroluminescent device according to claim 1, characterized in that: Also includes: A connection layer disposed between the second distributed Bragg reflector layer and the third distributed Bragg reflector layer; The connection layer is used to reduce interference between the light in the first wavelength band and the light in the second wavelength band.

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

5. The organic electroluminescent device according to claim 3, characterized in that: The material of the connection layer includes at least one of silicon oxide, titanium oxide and silicon nitride.

6. The organic electroluminescent device according to claim 2, characterized in that: The number of the first sublayers is an even number and is greater than or equal to 4; The number of the second sublayers is an even number and is greater than or equal to 4; The number of the third sublayers is an even number and is greater than or equal to 4.

7. The organic electroluminescent device according to claim 2, characterized in that: The refractive indexes of all even-numbered layers in the plurality of first sub-layers are the same, and the refractive indexes of all odd-numbered layers in the plurality of first sub-layers are the same; The refractive indexes of all even-numbered layers in the plurality of second sub-layers are the same, and the refractive indexes of all odd-numbered layers in the plurality of second sub-layers are the same; The refractive indexes of all even-numbered layers in the plurality of third sub-layers are the same, and the refractive indexes of all odd-numbered layers in the plurality of third sub-layers are the same.

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

9. The organic electroluminescent device according to claim 1, characterized in that: The organic light emitting layer has a higher emission efficiency for emitting light in the second wavelength band than for emitting light in the first wavelength band; The first band is the red light band; the second band is the infrared band; The organic electroluminescent device further comprises: 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 light-transmitting electrode is an anode and the reflective electrode is a 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 an anode and the light-transmitting electrode is a 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.

10. A light emitting device, characterized in that: The organic electroluminescent device comprises a plurality of organic electroluminescent devices according to any one of claims 1 to 9.

Images