Organic light emitting diode, display panel and display device

Abstract

The invention discloses an organic light emitting diode, a display panel and a display device, and relates to the technical field of display. The organic light emitting diode includes a first electrode, a second electrode, at least two light emitting layers, a first hole transport layer, and a second hole transport layer. Wherein the thickness of the second hole transport layer is relatively large, and the thickness ratio range of the second hole transport layer and the first hole transport layer is relatively large, so that under the condition that the thicknesses of other film layers between the first electrode and the second electrode are different, the microcavity length of the organic light-emitting diode is adjusted by selecting the second hole transport layers with different thicknesses; therefore, the optical performance of the organic light-emitting diode is ensured, and the display effect of the display panel is ensured.

Description

Organic light emitting diode, display panel and display device Technical Field

[0001] The present application relates to the field of display technology, and in particular to an organic light emitting diode, a display panel, and a display device. Background Art

[0002] Organic light emitting diodes (OLEDs) are widely used in display panels due to their advantages such as self-luminescence, wide viewing angle, high contrast, fast response time and flexible display.

[0003] Summary of the Invention

[0004] The present application provides an organic light emitting diode, a display panel, and a display device, and the technical solutions are as follows:

[0005] In one aspect, an organic light emitting diode is provided, comprising: a first electrode, a second electrode, at least two light emitting layers, a first hole transport layer, and a second hole transport layer;

[0006] The light emitted by the at least two light-emitting layers is mixed to form white light, and the at least two light-emitting layers include a first light-emitting layer and a second light-emitting layer, the first electrode, the first light-emitting layer, the first hole transport layer, the second hole transport layer, the second light-emitting layer, and the second electrode, which are located on a base substrate and are stacked in sequence in a direction away from the base substrate;

[0007] The thickness of the second hole transport layer is greater than a first thickness threshold, and a ratio of the thickness of the second hole transport layer to the thickness of the first hole transport layer is in a range of 15 to 40.

[0008] Optionally, the thickness of the second hole transport layer is less than a second thickness threshold;

[0009] The second thickness threshold is greater than the first thickness threshold.

[0010] Optionally, the first thickness threshold is 150 nanometers, and the second thickness threshold is 200 nanometers.

[0011] Optionally, the thickness of the first hole transport layer is in a range of 5 nanometers to 10 nanometers.

[0012] Optionally, the at least two light-emitting layers further include: a third light-emitting layer located between the first light-emitting layer and the second light-emitting layer;

[0013] The color of the light emitted by the first light-emitting layer is the same as the color of the light emitted by the second light-emitting layer, and the color of the light emitted by the third light-emitting layer is different from the color of the light emitted by the first light-emitting layer.

[0014] Optionally, the first hole transport layer is located between the first light-emitting layer and the third light-emitting layer, and the second hole transport layer is located between the third light-emitting layer and the second light-emitting layer.

[0015] Optionally, the at least two light-emitting layers further include: a fourth light-emitting layer located between the first light-emitting layer and the third light-emitting layer;

[0016] The light emitted by the fourth light-emitting layer has a different color from that of the light emitted by the first light-emitting layer, and also has a different color from that of the light emitted by the third light-emitting layer.

[0017] Optionally, the organic light-emitting diode further includes: a reflective layer located on a side of the first electrode close to the base substrate, and a hole injection layer, a third hole transport layer, and a first electron blocking layer located between the first electrode and the first light-emitting layer and stacked in sequence in a direction away from the base substrate;

[0018] Among them, the thickness range of the reflective layer is 50nm to 100nm, the thickness range of the first electrode is 5nm to 20nm, the thickness range of the hole injection layer is 5nm to 20nm, the thickness range of the third hole transport layer is 90nm to 130nm, and the thickness range of the first electron blocking layer is 5nm to 20nm.

[0019] Optionally, the organic light emitting diode further includes: a first hole blocking layer and an electron injection layer located between the second light emitting layer and the second electrode and stacked in sequence in a direction away from the base substrate;

[0020] The thickness of the first hole blocking layer ranges from 5 nanometers to 20 nanometers, and the thickness of the electron injection layer ranges from 80 nanometers to 100 nanometers.

[0021] Optionally, the organic light emitting diode further includes: a first hole blocking layer and an electron injection layer located between the second light emitting layer and the second electrode and stacked in sequence in a direction away from the base substrate;

[0022] The thickness of the first hole blocking layer ranges from 15 nanometers to 30 nanometers, and the thickness of the electron injection layer ranges from 180 nanometers to 200 nanometers.

[0023] Optionally, the organic light-emitting diode further includes: a reflective layer located on a side of the first electrode close to the base substrate, and a hole injection layer, a third hole transport layer, and a first electron blocking layer located between the first electrode and the first light-emitting layer and stacked in sequence in a direction away from the base substrate;

[0024] Among them, the thickness range of the reflective layer is 50nm to 100nm, the thickness range of the first electrode is 5nm to 10nm, the thickness range of the hole injection layer is 5nm to 10nm, the thickness range of the third hole transport layer is 5nm to 50nm, and the thickness range of the first electron blocking layer is 5nm to 10nm.

[0025] Optionally, the organic light-emitting diode further includes: a reflective layer located on a side of the first electrode close to the base substrate, and a hole injection layer, a third hole transport layer, and a first electron blocking layer located between the first electrode and the first light-emitting layer and stacked in sequence in a direction away from the base substrate;

[0026] Among them, the thickness range of the reflective layer is 50nm to 100nm, the thickness range of the first electrode is 5nm to 20nm, the thickness range of the hole injection layer is 20nm to 25nm, the thickness range of the third hole transport layer is 170nm to 210nm, and the thickness range of the first electron blocking layer is 20nm to 35nm.

[0027] Optionally, the organic light-emitting diode further includes: a reflective layer located on a side of the first electrode close to the base substrate, and a hole injection layer, a third hole transport layer, and a first electron blocking layer located between the first electrode and the first light-emitting layer and stacked in sequence in a direction away from the base substrate;

[0028] Among them, the thickness range of the reflective layer is 50nm to 100nm, the thickness range of the first electrode is 80nm to 100nm, the thickness range of the hole injection layer is 5nm to 20nm, the thickness range of the third hole transport layer is 5nm to 20nm, and the thickness range of the first electron blocking layer is 5nm to 20nm.

[0029] Optionally, the organic light-emitting diode further includes: a second hole blocking layer, a first charge generation layer, and a fourth hole transport layer located between the first light-emitting layer and the second light-emitting layer, the second hole blocking layer, the first charge generation layer, the fourth hole transport layer, and the second hole transport layer are stacked in sequence in a direction away from the substrate;

[0030] The thickness of the second hole blocking layer is in a range of 5 to 20 nanometers, the thickness of the first charge generation layer is in a range of 5 to 10 nanometers, and the thickness of the fourth hole transport layer is in a range of 5 to 10 nanometers.

[0031] Optionally, the organic light-emitting diode further includes: a second charge generation layer, a fifth hole transport layer, and a second electron blocking layer located between the third light-emitting layer and the second light-emitting layer, the second charge generation layer, the fifth hole transport layer, the first hole transport layer, and the second electron blocking layer being stacked in sequence in a direction away from the substrate;

[0032] The thickness of the second charge generation layer is in a range of 5 to 20 nanometers, the thickness of the fifth hole transport layer is in a range of 5 to 20 nanometers, and the thickness of the second electron blocking layer is in a range of 5 to 20 nanometers.

[0033] Optionally, the thickness of the first light-emitting layer ranges from 10 nanometers to 40 nanometers, the thickness of the second light-emitting layer ranges from 10 nanometers to 30 nanometers, the thickness of the third light-emitting layer ranges from 30 nanometers to 60 nanometers, and the thickness of the second electrode ranges from 80 nanometers to 120 nanometers.

[0034] On the other hand, a display panel is provided, comprising: a base substrate and a plurality of organic light emitting diodes as described above located on one side of the base substrate.

[0035] In another aspect, a display device is provided, comprising: a power supply component and the display panel according to the above aspect;

[0036] Wherein, the power supply component is used to supply power to the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] FIG1 is a schematic structural diagram of a display panel provided in an embodiment of the present application;

[0039] FIG2 is a schematic diagram of a color space provided in an embodiment of the present application;

[0040] FIG3 is a schematic structural diagram of another display panel provided in an embodiment of the present application;

[0041] FIG4 is a schematic diagram of the film thickness of an organic light emitting diode provided in an embodiment of the present application;

[0042] FIG5 is a schematic diagram of film thickness of another organic light emitting diode provided in an embodiment of the present application;

[0043] FIG6 is a schematic diagram of film thickness of another organic light emitting diode provided in an embodiment of the present application;

[0044] FIG7 is a schematic diagram of film thickness of another organic light emitting diode provided in an embodiment of the present application;

[0045] FIG8 is a schematic diagram of film thickness of another organic light emitting diode provided in an embodiment of the present application;

[0046] FIG9 is a schematic structural diagram of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0048] In related art, a display panel includes multiple organic light-emitting diodes (OLEDs), each of which may have an anode, a cathode, and an organic light-emitting film layer located between the anode and cathode. The distance between the anode and cathode layers (the thickness of the organic light-emitting film layer) is referred to as the microcavity length. The microcavity length affects the optical performance of the OLED, and therefore, the design of the organic light-emitting film layer thickness has a significant impact on the optical performance of the OLED.

[0049] However, the thickness of the organic light-emitting film layer in the related art makes it difficult for the organic light-emitting diode to achieve better optical performance, which in turn leads to poor display effect of the display panel.

[0050] FIG1 is a schematic diagram of the structure of a display panel provided in an embodiment of the present application. Referring to FIG1 , the organic light-emitting diode 1 in the display panel includes: a first electrode 101, a second electrode 102, at least two emission layers (EMLs) 103, a first hole transport layer (HTL) 104, and a second hole transport layer 105.

[0051] The mixed color of the light emitted by the at least two light-emitting layers 103 is white, that is, the organic light-emitting diode 1 can be used to emit white light.

[0052] 1 , the at least two light-emitting layers 103 include a first light-emitting layer 1031 and a second light-emitting layer 1032. Furthermore, the first electrode 101, the first light-emitting layer 1031, the first hole transport layer 104, the second hole transport layer 105, the second light-emitting layer 1032, and the second electrode 102 are positioned on the substrate 2 and stacked sequentially in a direction away from the substrate 2.

[0053] The thickness of the second hole transport layer 105 is greater than the first thickness threshold, and the ratio of the thickness of the second hole transport layer 105 to the thickness of the first hole transport layer 104 is in a range of 15 to 40.

[0054] In the embodiment of the present application, the thickness of the second hole transport layer 105 in the organic light-emitting diode 1 is greater than the first thickness threshold, that is, the thickness of the second hole transport layer 105 is relatively thick. Furthermore, the ratio of the thickness of the second hole transport layer 105 to the thickness of the first hole transport layer 104 is relatively wide. Consequently, the thickness of the second hole transport layer 105 can be modulated over a wide range. Therefore, even when the thicknesses of other film layers between the first electrode 101 and the second electrode 102 vary, the microcavity length of the organic light-emitting diode 1 can be adjusted by selecting second hole transport layers 105 of varying thicknesses, thereby ensuring the optical performance of the organic light-emitting diode 1 and the display quality of the display panel.

[0055] Optionally, the first electrode 101 can be an anode, and the second electrode 102 can be a cathode. Driven by an external driving voltage, electrons from the second electrode 102 and holes from the first electrode 101 move to the light-emitting layer of the organic light-emitting diode 1. When the holes and electrons meet in the light-emitting layer, energy excitons are generated, which excite the light-emitting molecules and ultimately produce visible light.

[0056] Optionally, the material of the first electrode 101 may be indium tin oxide (ITO). The material of the second electrode 102 may be indium zinc oxide (IZO). The commonly used preparation method of indium zinc oxide is sputtering.

[0057] In summary, the embodiments of the present application provide an organic light-emitting diode (OLED), comprising a first electrode, a second electrode, at least two light-emitting layers, a first hole transport layer, and a second hole transport layer. The second hole transport layer is relatively thick, and has a relatively large ratio to the thickness of the first hole transport layer. Therefore, when the thicknesses of other film layers between the first and second electrodes vary, by selecting second hole transport layers of varying thicknesses, the microcavity length of the OLED can be adjusted, thereby ensuring the optical performance of the OLED and the display quality of the display panel.

[0058] Optionally, the electron mobility of the second hole transport layer 105 is in the range of 10 -1 cm 2 / V·S (square centimeter / volt·second) to 10cm 2 / V·S.

[0059] The thickness of the second hole transport layer 105 is less than a second thickness threshold, which is greater than the first thickness threshold. In other words, the thickness of the second hole transport layer 105 is not too great, thereby ensuring the effectiveness of the second hole transport layer 105 in transporting holes and the reliability of the injection of electrons generated by the second electrode 102 into the light-emitting layer.

[0060] The thickness of the second hole transport layer 105 is not only greater than the first thickness threshold, but also less than the first thickness threshold. Therefore, the organic light emitting diode 1 can not only ensure good optical performance, but also ensure hole transport and electron injection, and the display panel has a good display effect.

[0061] Optionally, the first thickness threshold is 150 nm, and the second thickness threshold is 200 nm. That is, the thickness of the second hole transport layer 105 ranges from 150 nm to 200 nm.

[0062] Table 1

[0063] As shown in Table 1 above, the voltage (V), color point (CIEx), color point (CIEy), and lifetime of the second hole transport layer 105 with a thickness range of 150nm to 200nm are not significantly different from those with a thickness range of 10nm to 20nm. Furthermore, referring to FIG2 , the color point after passing through the green color filter can be relatively blue-shifted (the green blue shift is shown as the coordinates (0.109, 0.575) moving to (0.102, 0.576) in FIG2 ), and the color point changes from (0.285, 0.667) to (0.271, 0.678). The color point after passing through the red color filter can be relatively red-shifted (the red red shift is shown as the coordinates (0.490, 0.526) moving to (0.497, 0.525) in FIG2 ), and the color point changes from (0.676, 0.323) to (0.680, 0.319). The DCI-P3 color gamut increases from 97.2% to 99.3%, extending the color gamut range. This value has already reached a relatively high level. Furthermore, although increasing the thickness of the second hole transport layer 105 slightly affects the luminous efficiency, as shown in Table 1, which decreases from 100% to 85%, this luminous efficiency still meets product requirements.

[0064] 2 , the solid triangle represents the color space of the color gamut standard DCI-P3 on CIE1976, and the dotted triangle represents the color space when the thickness of the second hole transport layer is 10 nm to 20 nm.

[0065] In Table 1, "thickness" refers to the thickness of the second hole transport layer 105, "green filter" refers to the color point after the green filter, and "red filter" refers to the color point after the red filter. "Lifespan" refers to the lifetime at which the luminous efficiency decays to 95% at a current density of 50 J, denoted as "LT95@50 J."

[0066] In the embodiment of the present application, the ratio of the thickness of the second hole transport layer 105 to the thickness of the first hole transport layer 104 is in a range of 15 to 40. The thickness of the second hole transport layer 105 is in a range of 150 nm to 200 nm. Thus, the thickness of the first hole transport layer 104 is in a range of 5 nm to 10 nm.

[0067] 3 , the at least two light-emitting layers 103 further include a third light-emitting layer 1033 located between the first light-emitting layer 1031 and the second light-emitting layer 1032. The color of light emitted by the first light-emitting layer 1031 is the same as the color of light emitted by the second light-emitting layer 1032, and the color of light emitted by the third light-emitting layer 1033 is different from the color of light emitted by the first light-emitting layer 1031.

[0068] Optionally, the color of the light emitted by the first light-emitting layer 1031 and the color of the light emitted by the second light-emitting layer 1032 are blue (blue, B), and the color of the light emitted by the third light-emitting layer 1033 is yellow (yello, Y). That is, the first light-emitting layer 1031 and the second light-emitting layer 1032 are both blue emission layers (blue emission layer, B-EML), and the third light-emitting layer 1033 is a yellow emission layer (yello emission layer, Y-EML).

[0069] In addition, the first hole transport layer 104 is located between the first light-emitting layer 1031 and the third light-emitting layer 1033, and the second hole transport layer 105 is located between the third light-emitting layer 1033 and the second light-emitting layer 1032. In other words, in the embodiment of the present application, the hole transport layer located between the third light-emitting layer 1033 and the second light-emitting layer 1032 is designed to be thicker.

[0070] Furthermore, the at least two light-emitting layers 103 further include a fourth light-emitting layer 1034 located between the first light-emitting layer 1031 and the third light-emitting layer 1033. The color of light emitted by the fourth light-emitting layer 1034 is different from the color of light emitted by the first light-emitting layer 1031 and the color of light emitted by the third light-emitting layer 1033. Optionally, the color of light emitted by the fourth light-emitting layer 1034 is red (red, R). In other words, the fourth light-emitting layer 1034 is a red emission layer (R-EML).

[0071] As can be seen from FIG3 , the organic light-emitting diode 1 further includes a reflective layer 106 located on the side of the first electrode closest to the base substrate, and a hole injection layer (HIL) 107, a third hole transport layer 108, and a first electron block layer (EBL) 109 located between the first electrode 101 and the first light-emitting layer 1031 and stacked sequentially in a direction away from the base substrate 2. The reflective layer 106 can be made of at least one of aluminum (Al), silver (Ag), and molybdenum (Mo).

[0072] Optionally, the thickness of the reflective layer 106 is in a range of 50 nm to 100 nm, the thickness of the first electrode 101 is in a range of 5 nm to 20 nm, the thickness of the hole injection layer 107 is in a range of 5 nm to 20 nm, the thickness of the third hole transport layer 108 is in a range of 90 nm to 130 nm, and the thickness of the first electron blocking layer 109 is in a range of 5 nm to 20 nm. Alternatively, the thickness of the first electrode 101 is in a range of 5 nm to 10 nm, the thickness of the hole injection layer 107 is in a range of 5 nm to 10 nm, the thickness of the first hole transport layer 104 is in a range of 5 nm to 50 nm, and the thickness of the first electron blocking layer 109 is in a range of 5 nm to 10 nm. Alternatively, the thickness of the first electrode 101 ranges from 5 nm to 20 nm, the thickness of the hole injection layer 107 ranges from 20 nm to 25 nm, the thickness of the first hole transport layer 104 ranges from 170 nm to 210 nm, and the thickness of the first electron blocking layer 109 ranges from 20 nm to 35 nm. Alternatively, the thickness of the first electrode 101 ranges from 80 nm to 100 nm, the thickness of the hole injection layer 107 ranges from 5 nm to 20 nm, the thickness of the first hole transport layer 104 ranges from 5 nm to 20 nm, and the thickness of the first electron blocking layer 109 ranges from 5 nm to 20 nm.

[0073] 3 , the organic light emitting diode 1 further includes: a first hole block layer (HBL) 110 and an electron injection layer (EIL) 111 located between the second light emitting layer 1032 and the second electrode 102 and stacked sequentially in a direction away from the base substrate 2 .

[0074] Optionally, the thickness of the first hole blocking layer 110 ranges from 5 nm to 20 nm, and the thickness of the electron injection layer 111 ranges from 80 nm to 100 nm. Alternatively, the thickness of the first hole blocking layer 110 ranges from 15 nm to 30 nm, and the thickness of the electron injection layer 111 ranges from 180 nm to 200 nm.

[0075] 3 , the organic light-emitting diode 1 further includes a second hole blocking layer 112, a first charge-generation layer (CGL) 113, and a fourth hole transport layer 114, located between the first light-emitting layer 1031 and the third light-emitting layer 1033. The second hole blocking layer 112, the first charge generation layer 113, the fourth hole transport layer 114, and the first hole transport layer 104 are stacked sequentially in a direction away from the base substrate 2.

[0076] Optionally, the thickness of the second hole blocking layer 112 ranges from 5 nm to 20 nm, the thickness of the first charge generation layer 113 ranges from 5 nm to 10 nm, and the thickness of the fourth hole transport layer 114 ranges from 5 nm to 10 nm.

[0077] 3 , the organic light-emitting diode 1 further includes a second charge generation layer 115, a fifth hole transport layer 116, and a second electron blocking layer 117 located between the third light-emitting layer 1033 and the second light-emitting layer 1032. The second charge generation layer 115, the fifth hole transport layer 116, the second hole transport layer 105, and the second electron blocking layer 117 are stacked sequentially in a direction away from the substrate 2.

[0078] Optionally, the thickness of the second charge generation layer 115 is in a range of 5 nm to 20 nm, the thickness of the fifth hole transport layer 116 is in a range of 5 nm to 20 nm, and the thickness of the second electron blocking layer 117 is in a range of 5 nm to 20 nm.

[0079] In addition, in the embodiment of the present application, the thickness range of the first light-emitting layer 1031 is 10nm to 30nm, the thickness range of the second light-emitting layer 1032 is 10nm to 30nm, the thickness range of the third light-emitting layer 1033 is 30nm to 60nm, and the thickness range of the second electrode 102 is 80nm to 120nm.

[0080] In the embodiment of the present application, different thickness settings can be used to ensure the optical performance of the organic light emitting diode 1. Optionally, the thickness schemes include the following:

[0081] Scheme 1, referring to Figure 4, the thickness of the film layers stacked in the direction away from the substrate 2 are: the thickness of the reflective layer 106 ranges from 50nm to 100nm, the thickness of the first electrode ranges from 5nm to 20nm; the thickness of the hole injection layer 107 ranges from 5nnm to 20nm; the thickness of the third hole transport layer 108 ranges from 90nm to 130nm; the thickness of the first electron blocking layer 109 ranges from 5nm to 20nm; the thickness of the first light-emitting layer 1031 ranges from 10nm to 30nm; the thickness of the second hole blocking layer 112 ranges from 5nm to 20nm, the thickness of the first charge generation layer 113 ranges from 5nm to 10nm, the thickness of the fourth hole transport layer 114 ranges from 5nm to 10nm; the thickness of the first hole transport layer 104 ranges from 10nm to 10nm. The thickness range of the fourth light-emitting layer 1034 is 5nm to 20nm; the thickness range of the third light-emitting layer 1033 is 30nm to 60nm; the thickness range of the second charge generation layer 115 is 5nm to 20nm; the thickness range of the fifth hole transport layer 116 is 5nm to 20nm, and the thickness range of the second hole transport layer 105 is 150nm to 200nm; the thickness range of the second electron blocking layer 117 is 5nm to 20nm; the thickness range of the second light-emitting layer 1032 is 10nm to 30nm; the thickness range of the first hole blocking layer 110 is 5nm to 20nm; the thickness range of the electron injection layer 111 is 80nm to 100nm; the thickness range of the second electrode 102 is 80nm to 120nm.

[0082] In the first solution, the distance between the second light-emitting layer 1032 close to the substrate 2 and the reflective layer 106 ranges from 335nm to 610nm, and the distance between the second light-emitting layer 1032 close to the substrate 2 and the second electrode 102 ranges from 95nm to 150nm.

[0083] Option 2, referring to Figure 5, the thickness of the film layers stacked in the direction away from the substrate 2 are: the thickness of the reflective layer 106 ranges from 50nm to 100nm; the thickness of the first electrode 101 ranges from 5nm to 10nm; the thickness of the hole injection layer 107 ranges from 5nnm to 10nm; the thickness of the third hole transport layer 108 ranges from 5nm to 50nm; the thickness of the first electron blocking layer 109 ranges from 5nm to 10nm; the thickness of the first light-emitting layer 1031 ranges from 10nm to 30nm; the thickness of the second hole blocking layer 112 ranges from 5nm to 20nm, the thickness of the first charge generation layer 113 ranges from 5nm to 10nm, the thickness of the fourth hole transport layer 114 ranges from 5nm to 10nm; the thickness of the first hole transport layer 104 ranges from 5nm to 20nm The thickness range of the fourth light-emitting layer 1034 is 5nm to 20nm; the thickness range of the third light-emitting layer 1033 is 30nm to 60nm; the thickness range of the second charge generation layer 115 is 5nm to 20nm; the thickness range of the fifth hole transport layer 116 is 5nm to 20nm, and the thickness range of the second hole transport layer 105 is 150nm to 200nm; the thickness range of the second electron blocking layer 117 is 5nm to 20nm; the thickness range of the second light-emitting layer 1032 is 10nm to 30nm; the thickness range of the first hole blocking layer 110 is 5nm to 20nm; the thickness range of the electron injection layer 111 is 80nm to 100nm; the thickness range of the second electrode 102 is 80nm to 120nm.

[0084] Among them, in the second solution, the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the reflective layer 106 ranges from 250nm to 500nm, and the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the second electrode 102 ranges from 95nm to 150nm.

[0085] Scheme three, referring to Figure 6, the thickness of the film layers stacked in the direction away from the substrate 2 are as follows: the thickness of the reflective layer 106 ranges from 50nm to 100nm; the thickness of the first electrode 101 ranges from 5nm to 20nm; the thickness of the hole injection layer 107 ranges from 20nnm to 35nm; the thickness of the third hole transport layer 108 ranges from 170nm to 210nm; the thickness of the first electron blocking layer 109 ranges from 20nm to 35nm; the thickness of the first light-emitting layer 1031 ranges from 10nm to 30nm; the thickness of the second hole blocking layer 112 ranges from 5nm to 20nm, the thickness of the first charge generation layer 113 ranges from 5nm to 10nm, the thickness of the fourth hole transport layer 114 ranges from 5nm to 10nm; the first hole transport layer 104 the thickness range of the fourth light-emitting layer 1034 is 5nm to 20nm; the thickness range of the third light-emitting layer 1033 is 30nm to 60nm; the thickness range of the second charge generation layer 115 is 5nm to 20nm; the thickness range of the fifth hole transport layer 115 is 5nm to 20nm, and the thickness range of the second hole transport layer 105 is 150nm to 200nm; the thickness range of the second electron blocking layer 117 is 5nm to 20nm; the thickness range of the second light-emitting layer 1032 is 10nm to 30nm; the thickness range of the first hole blocking layer 110 is 5nm to 20nm; the thickness range of the electron injection layer 111 is 80nm to 100nm; and the thickness range of the second electrode 102 is 80nm to 120nm.

[0086] Among them, in the third scheme, the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the reflective layer 106 ranges from 425nm to 720nm, and the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the second electrode 102 ranges from 95nm to 150nm.

[0087] Scheme 4, referring to Figure 7, the thickness of the film layers stacked in the direction away from the substrate 2 are as follows: the thickness of the reflective layer 106 ranges from 50nm to 100nm; the thickness of the first electrode 101 ranges from 80nm to 100nm; the thickness of the hole injection layer 107 ranges from 5nm to 20nm; the thickness of the third hole transport layer 108 ranges from 5nm to 20nm; the thickness of the first electron blocking layer 109 ranges from 5nm to 20nm; the thickness of the first light-emitting layer 1031 ranges from 10nm to 30nm; the thickness of the second hole blocking layer 112 ranges from 5nm to 20nm, the thickness of the first charge generation layer 113 ranges from 5nm to 10nm, the thickness of the fourth hole transport layer 114 ranges from 5nm to 10nm; the thickness of the first hole transport layer 104 ranges from 10nm to 20nm. The thickness range of the fourth light-emitting layer 1034 is 5nm to 20nm; the thickness range of the third light-emitting layer 1033 is 30nm to 60nm; the thickness range of the second charge generation layer 115 is 5nm to 20nm; the thickness range of the fifth hole transport layer 116 is 5nm to 20nm, and the thickness range of the second hole transport layer 105 is 150nm to 200nm; the thickness range of the second electron blocking layer 117 is 5nm to 20nm; the thickness range of the second light-emitting layer 1032 is 10nm to 30nm; the thickness range of the first hole blocking layer 110 is 5nm to 20nm; the thickness range of the electron injection layer 111 is 80nm to 100nm; and the thickness range of the second electrode 102 is 80nm to 120nm.

[0088] Among them, in the fourth scheme, the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the reflective layer 106 ranges from 325nm to 580nm, and the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the second electrode 102 ranges from 95nm to 150nm.

[0089] Scheme 5, referring to FIG8 , the thicknesses of the film layers stacked in the direction away from the substrate 2 are as follows: the thickness of the reflective layer 106 ranges from 50 nm to 100 nm; the thickness of the first electrode 101 ranges from 5 nm to 20 nm; the thickness of the hole injection layer 107 ranges from 5 nm to 20 nm; the thickness of the third hole transport layer 108 ranges from 90 nm to 130 nm; the thickness of the first electron blocking layer 109 ranges from 5 nm to 20 nm; the thickness of the first light emitting layer 1031 ranges from 10 nm to 30 nm; the thickness of the second The thickness of the hole blocking layer 112 is in the range of 5 nm to 20 nm, the thickness of the first charge generation layer 113 is in the range of 5 nm to 10 nm, and the thickness of the fourth hole transport layer 114 is in the range of 5 nm to 10 nm; the thickness of the first hole transport layer 104 is in the range of 5 nm to 10 nm; the thickness of the fourth light emitting layer 1034 is in the range of 5 nm to 20 nm; the thickness of the third light emitting layer 1033 is in the range of 30 nm to 60 nm; the thickness of the second charge generation layer 115 is in the range of 5 nm to 20 nm; the thickness of the fifth hole transport layer 116 is in the range of 5 nm to 10 nm. The thickness range of the second hole transport layer 105 is 5nm to 20nm, the thickness range of the second electron blocking layer 117 is 5nm to 20nm; the thickness range of the second light-emitting layer 1032 is 10nm to 30nm; the thickness range of the first hole blocking layer 110 is 15nm to 30nm; the thickness range of the electron injection layer 111 is 180nm to 200nm; the thickness range of the second electrode 102 is 80nm to 120nm.

[0090] Among them, in the fifth scheme, the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the reflective layer 106 ranges from 335nm to 610nm, and the distance between the side of the second light-emitting layer 1032 close to the base substrate 2 and the second electrode 102 ranges from 205nm to 260nm.

[0091] In the embodiment of the present application, the first hole transport layer 104, the second hole transport layer 105, and the third hole transport layer 108 can all be conventional hole transport layers, denoted as HTL. The fourth hole transport layer 114 and the fifth hole transport layer 116 can both be P-type hole transport layers, denoted as P-HTL. The P-type hole transport layer can refer to a conventional hole transport layer doped with a material with a relatively low LUMO energy level. For example, a conventional hole transport layer is doped with HATCN, and its doping ratio ranges from 4% to 20%.

[0092] Alternatively, the first charge generation layer 113 and the second charge generation layer 115 may be conventional electron transport layers doped with lithium, or conventional electron transport layers doped with lithium octahydroxyquinoline and ytterbium, with the doping ratio ranging from 1.5% to 10%. The first charge generation layer 113 and the second charge generation layer 115 may both be referred to as N-CGL.

[0093] In summary, the embodiments of the present application provide an organic light-emitting diode (OLED), comprising a first electrode, a second electrode, at least two light-emitting layers, a first hole transport layer, and a second hole transport layer. The second hole transport layer is relatively thick, and has a relatively large ratio to the thickness of the first hole transport layer. Therefore, when the thicknesses of other film layers between the first and second electrodes vary, by selecting second hole transport layers of varying thicknesses, the microcavity length of the OLED can be adjusted, thereby ensuring the optical performance of the OLED and the display quality of the display panel.

[0094] The present application also provides a display panel, as shown in Figures 1 and 3 . The display panel 01 includes a base substrate 2 and a plurality of organic light emitting diodes 1 provided in the above embodiments, located on one side of the base substrate 2. Figures 1 and 3 schematically illustrate only one organic light emitting diode.

[0095] Since the display panel can have substantially the same technical effects as the organic light emitting diode described in the previous embodiment, the technical effects of the display panel will not be repeatedly described here for the purpose of brevity.

[0096] FIG9 is a schematic diagram of the structure of a display device provided in an embodiment of the present application. Referring to FIG9 , the display device includes: a power supply component 02 and a display panel 01 provided in the above embodiment. The power supply component 02 is used to supply power to the display panel 01.

[0097] Optionally, the display device may be an OLED display device, which may be any appropriate display device, including but not limited to mobile phones, tablet computers, televisions, monitors, laptop computers, digital photo frames, navigators, e-books, and any other products or components with display functions.

[0098] Since the display device can have substantially the same technical effects as the organic light emitting diode 1 described in the previous embodiment, the technical effects of the display device will not be repeatedly described here for the purpose of brevity.

[0099] It will be understood that, although the terms first and second, etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another region, layer or part. Therefore, the first element, component, region, layer or part discussed above may be referred to as a second element, component, region, layer or part without departing from the teachings of the present disclosure.

[0100] Spatially relative terms such as “under,” “over,” “left,” “right,” and the like may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the figures for ease of description. It will be understood that these spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figure is flipped, the element described as “under other elements or features” will be oriented “over other elements or features.” Therefore, the exemplary term “under” can encompass both orientations of over and under. The device can be oriented in other ways (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein are interpreted accordingly. In addition, it will also be understood that when a layer is referred to as “between two layers,” it can be the only layer between the two layers, or one or more intermediate layers can also be present.

[0101] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "one", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms "include" and / or "comprise" specify the existence of the features, integral bodies, steps, operations, elements and / or parts when used in this specification, but do not exclude the existence of one or more other features, integral bodies, steps, operations, elements, parts and / or their groups or add one or more other features, integral bodies, steps, operations, elements, parts and / or their groups. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. In this specification, the specific features, structures, materials or characteristics of description can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples without contradicting each other.

[0102] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant art and / or the context of this specification, and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0103] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An organic light emitting diode, characterized in that: The organic light emitting diode (1) comprises: a first electrode (101), a second electrode (102), at least two light emitting layers (103), a first hole transport layer (104) and a second hole transport layer (105); The light emitted by the at least two light-emitting layers (103) is mixed to form a white color; the at least two light-emitting layers (103) include a first light-emitting layer (1031) and a second light-emitting layer (1032); the first electrode (101), the first light-emitting layer (1031), the first hole transport layer (104), the second hole transport layer (105), the second light-emitting layer (1032), and the second electrode (102) are located on a base substrate (2) and are stacked in sequence in a direction away from the base substrate (2); The thickness of the second hole transport layer (105) is greater than a first thickness threshold, and the ratio of the thickness of the second hole transport layer (105) to the thickness of the first hole transport layer (104) is in the range of 15 to 40.

2. The organic light emitting diode according to claim 1, characterized in that: The thickness of the second hole transport layer (105) is less than a second thickness threshold; The second thickness threshold is greater than the first thickness threshold.

3. The organic light emitting diode according to claim 2, characterized in that: The first thickness threshold is 150 nanometers, and the second thickness threshold is 200 nanometers.

4. The organic light emitting diode according to claim 3, characterized in that: The thickness of the first hole transport layer (104) is in the range of 5 nanometers to 10 nanometers.

5. The organic light emitting diode according to any one of claims 1 to 4, characterized in that: The at least two light-emitting layers (103) further include: a third light-emitting layer (1033) located between the first light-emitting layer (1031) and the second light-emitting layer (1032); The color of the light emitted by the first light-emitting layer (1031) is the same as the color of the light emitted by the second light-emitting layer (1032), and the color of the light emitted by the third light-emitting layer (1033) is different from the color of the light emitted by the first light-emitting layer (1031).

6. The organic light emitting diode according to claim 5, characterized in that: The first hole transport layer (104) is located between the first light-emitting layer (1031) and the third light-emitting layer (1033), and the second hole transport layer (105) is located between the third light-emitting layer (1033) and the second light-emitting layer (1032).

7. The organic light emitting diode according to claim 5 or 6, characterized in that: The at least two light-emitting layers (103) further include: a fourth light-emitting layer (1034) located between the first light-emitting layer (1031) and the third light-emitting layer (1033); The light emitted by the fourth light-emitting layer (1034) has a different color from the light emitted by the first light-emitting layer (1031), and has a different color from the light emitted by the third light-emitting layer (1033).

8. The organic light emitting diode according to claim 7, characterized in that: The organic light emitting diode (1) further comprises: a reflective layer (106) located on a side of the first electrode (101) close to the base substrate (2), and a hole injection layer (107), a third hole transport layer (108) and a first electron blocking layer (109) located between the first electrode (101) and the first light emitting layer (1031) and stacked in sequence in a direction away from the base substrate (2); The thickness of the reflective layer (106) is in the range of 50 nm to 100 nm, the thickness of the first electrode (101) is in the range of 5 nm to 20 nm, the thickness of the hole injection layer (107) is in the range of 5 nm to 20 nm, the thickness of the third hole transport layer (108) is in the range of 90 nm to 130 nm, and the thickness of the first electron blocking layer (109) is in the range of 5 nm to 20 nm.

9. The organic light emitting diode according to claim 8, characterized in that: The organic light emitting diode (1) further comprises: a first hole blocking layer (110) and an electron injection layer (111) which are located between the second light emitting layer (1032) and the second electrode (102) and are sequentially stacked in a direction away from the base substrate (2); The thickness of the first hole blocking layer (110) is in the range of 5 nanometers to 20 nanometers, and the thickness of the electron injection layer (111) is in the range of 80 nanometers to 100 nanometers.

10. The organic light emitting diode according to claim 8, characterized in that: The organic light emitting diode (1) further comprises: a first hole blocking layer (110) and an electron injection layer (111) which are located between the second light emitting layer (1032) and the second electrode (102) and are sequentially stacked in a direction away from the base substrate (2); The thickness of the first hole blocking layer (110) is in the range of 15 nanometers to 30 nanometers, and the thickness of the electron injection layer (111) is in the range of 180 nanometers to 200 nanometers.

11. The organic light emitting diode according to claim 7, characterized in that: The organic light emitting diode (1) further comprises: a reflective layer (106) located on a side of the first electrode (101) close to the base substrate (2), and a hole injection layer (107), a third hole transport layer (108) and a first electron blocking layer (109) located between the first electrode (101) and the first light emitting layer (1031) and stacked in sequence in a direction away from the base substrate (2); The thickness of the reflective layer (106) is in the range of 50 nm to 100 nm, the thickness of the first electrode (101) is in the range of 5 nm to 10 nm, the thickness of the hole injection layer (107) is in the range of 5 nm to 10 nm, the thickness of the third hole transport layer (108) is in the range of 5 nm to 50 nm, and the thickness of the first electron blocking layer (109) is in the range of 5 nm to 10 nm.

12. The organic light emitting diode according to claim 7, characterized in that: The organic light emitting diode (1) further comprises: a reflective layer (106) located on a side of the first electrode (101) close to the base substrate (2), and a hole injection layer (107), a third hole transport layer (108) and a first electron blocking layer (109) located between the first electrode (101) and the first light emitting layer (1031) and stacked in sequence in a direction away from the base substrate (2); The thickness of the reflective layer (106) is in the range of 50 nm to 100 nm, the thickness of the first electrode (101) is in the range of 5 nm to 20 nm, the thickness of the hole injection layer (107) is in the range of 20 nm to 25 nm, the thickness of the third hole transport layer (108) is in the range of 170 nm to 210 nm, and the thickness of the first electron blocking layer (109) is in the range of 20 nm to 35 nm.

13. The organic light emitting diode according to claim 7, characterized in that: The organic light emitting diode (1) further comprises: a reflective layer (106) located on a side of the first electrode (101) close to the base substrate (2), and a hole injection layer (107), a third hole transport layer (108) and a first electron blocking layer (109) located between the first electrode (101) and the first light emitting layer (1031) and stacked in sequence in a direction away from the base substrate (2); The thickness of the reflective layer (106) is in the range of 50 nm to 100 nm, the thickness of the first electrode (101) is in the range of 80 nm to 100 nm, the thickness of the hole injection layer (107) is in the range of 5 nm to 20 nm, the thickness of the third hole transport layer (108) is in the range of 5 nm to 20 nm, and the thickness of the first electron blocking layer (109) is in the range of 5 nm to 20 nm.

14. The organic light emitting diode according to any one of claims 5 to 13, characterized in that: The organic light emitting diode (1) further comprises: a second hole blocking layer (112), a first charge generation layer (113), and a fourth hole transport layer (114) located between the first light emitting layer (1031) and the third light emitting layer (1033), wherein the second hole blocking layer (112), the first charge generation layer (113), the fourth hole transport layer (114), and the first hole transport layer (104) are stacked in sequence along a direction away from the base substrate (2); The thickness of the second hole blocking layer (112) is in the range of 5 nanometers to 20 nanometers, the thickness of the first charge generation layer (113) is in the range of 5 nanometers to 10 nanometers, and the thickness of the fourth hole transport layer (114) is in the range of 5 nanometers to 10 nanometers.

15. The organic light emitting diode according to any one of claims 5 to 14, characterized in that: The organic light emitting diode (1) further comprises: a second charge generation layer (115), a fifth hole transport layer (116), and a second electron blocking layer (117) located between the third light emitting layer (1033) and the second light emitting layer (1032), wherein the second charge generation layer (115), the fifth hole transport layer (116), the first hole transport layer (104), and the second electron blocking layer (117) are stacked in sequence along a direction away from the base substrate (2); The thickness of the second charge generation layer (115) is in the range of 5 nanometers to 20 nanometers, the thickness of the fifth hole transport layer (116) is in the range of 5 nanometers to 20 nanometers, and the thickness of the second electron blocking layer (117) is in the range of 5 nanometers to 20 nanometers.

16. The organic light emitting diode according to any one of claims 5 to 15, characterized in that: The thickness of the first light-emitting layer (1031) ranges from 10 nanometers to 40 nanometers, the thickness of the second light-emitting layer (1032) ranges from 10 nanometers to 30 nanometers, the thickness of the third light-emitting layer (1033) ranges from 30 nanometers to 60 nanometers, and the thickness of the second electrode (102) ranges from 80 nanometers to 120 nanometers.

17. A display panel, characterized in that: The display panel (01) comprises: a base substrate (2) and a plurality of organic light emitting diodes (1) according to any one of claims 1 to 16, located on one side of the base substrate (2).

18. A display device, characterized in that: The display device comprises: a power supply component (02) and a display panel (01) as claimed in claim 17; Wherein, the power supply component (02) is used to supply power to the display panel (01).

Images