Light-emitting device, display panel, and display apparatus

Abstract

The present application relates to the technical field of display. Disclosed are a light-emitting device, a display panel, and a display apparatus. The light-emitting device comprises a first electrode, a first electroluminescent unit, a second electrode, a second electroluminescent unit and a third electrode, which are located on a base substrate and are sequentially stacked. The first electroluminescent unit can emit light under the joint action of the first electrode and the second electrode, and the second electroluminescent unit can emit light under the joint action of the second electrode and the third electrode. Since the reflectivity of at least one of the second electrode and the third electrode is relatively great, the light emitted by the first electroluminescent unit and the light emitted by the second electroluminescent unit can be reflected at the electrode with the relatively great reflectivity, such that the interference effect of light is enhanced, and the microcavity strength of the light-emitting device is improved, thereby improving the optical performance of the light-emitting device and improving the brightness of a display panel.

Description

Light-emitting device, display panel, and display apparatus Technical Field

[0001] The present application relates to the field of display technology, and in particular to a light-emitting device, a display panel, and a display apparatus. 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 a light-emitting device, a display panel, and a display apparatus, and the technical solutions are as follows:

[0005] In one aspect, a light emitting device is provided, comprising: a first electrode, a first electroluminescent unit, a second electrode, a second electroluminescent unit, and a third electrode, which are located on a substrate and stacked in sequence;

[0006] The color of the light emitted by the first electroluminescent unit is different from the color of the light emitted by the second electroluminescent unit; the potential of the first electrode is higher than the potential of the second electrode and higher than the potential of the third electrode, the potential of the second electrode is different from the potential of the third electrode, and the reflectivity of at least one of the second electrode and the third electrode is greater than 10%.

[0007] Optionally, the potential of the second electrode is higher than the potential of the third electrode;

[0008] The first electroluminescent unit includes: a first hole transport layer, a first light-emitting layer and a first electron transport layer stacked in sequence in a direction away from the base substrate;

[0009] The second electroluminescent unit includes: a second hole transport layer, a second light emitting layer, and a second electron transport layer sequentially stacked in a direction away from the base substrate.

[0010] Optionally, the work function of the material of the first electrode is greater than the work function of the material of the second electrode and greater than the work function of the material of the third electrode, and the work function of the material of the second electrode is greater than the work function of the material of the third electrode.

[0011] Optionally, the material of the first electrode is indium tin oxide, the material of the second electrode is aluminum, and the material of the third electrode is magnesium silver alloy;

[0012] The thickness of the first electrode ranges from 60 nanometers to 80 nanometers; the thickness of the second electrode ranges from 10 nanometers to 30 nanometers; and the thickness of the third electrode ranges from 80 nanometers to 120 nanometers.

[0013] Optionally, the light-emitting device further comprises: a fourth electrode and a third electroluminescent unit located between the first electroluminescent unit and the second electrode; wherein the potential of the fourth electrode is lower than the potential of the first electrode and higher than the potential of the second electrode;

[0014] The third electroluminescent unit includes: a third hole transport layer, a third light-emitting layer and a third electron transport layer stacked in sequence in a direction away from the base substrate.

[0015] Optionally, the work function of the material of the first electrode is greater than the work function of the material of the fourth electrode, greater than the work function of the material of the second electrode, and greater than the work function of the material of the third electrode;

[0016] The work function of the material of the fourth electrode is greater than the work function of the material of the second electrode, and greater than the work function of the material of the third electrode;

[0017] A work function of a material of the second electrode is greater than a work function of a material of the third electrode.

[0018] Optionally, the material of the first electrode is indium tin oxide, the material of the fourth electrode is indium zinc oxide, the material of the second electrode is aluminum, and the material of the third electrode is magnesium silver alloy;

[0019] The thickness of the first electrode ranges from 60 nanometers to 80 nanometers; the thickness of the fourth electrode ranges from 10 nanometers to 30 nanometers; the thickness of the second electrode ranges from 10 nanometers to 30 nanometers; and the thickness of the third electrode ranges from 80 nanometers to 120 nanometers.

[0020] Optionally, the potential of the third electrode is higher than the potential of the second electrode;

[0021] The first electroluminescent unit includes: a first hole transport layer, a first light-emitting layer and a first electron transport layer stacked in sequence in a direction away from the base substrate;

[0022] The second electroluminescent unit includes: a second electron transport layer, a second light-emitting layer, and a second hole transport layer sequentially stacked in a direction away from the base substrate.

[0023] Optionally, the work function of the material of the first electrode is greater than the work function of the material of the second electrode, and greater than the work function of the material of the third electrode, and the work function of the material of the third electrode is greater than the work function of the material of the second electrode.

[0024] Optionally, the material of the first electrode is indium tin oxide, the material of the second electrode is magnesium silver alloy, and the material of the third electrode is aluminum;

[0025] The thickness of the first electrode ranges from 60 nanometers to 80 nanometers; the thickness of the second electrode ranges from 10 nanometers to 40 nanometers; and the thickness of the third electrode ranges from 80 nanometers to 120 nanometers.

[0026] Optionally, the light-emitting device further comprises: a fourth electrode and a third electroluminescent unit located between the first electroluminescent unit and the second electrode; wherein the potential of the fourth electrode is lower than the potential of the first electrode and higher than the potential of the second electrode;

[0027] The third electroluminescent unit includes: a third hole transport layer, a third light-emitting layer and a third electron transport layer stacked in sequence in a direction away from the base substrate.

[0028] Optionally, the work function of the material of the first electrode is greater than the work function of the material of the fourth electrode, greater than the work function of the material of the second electrode, and greater than the work function of the material of the third electrode;

[0029] The work function of the material of the fourth electrode is greater than the work function of the material of the second electrode, and greater than the work function of the material of the third electrode;

[0030] A work function of the third electrode is greater than a work function of a material of the second electrode.

[0031] Optionally, the material of the first electrode is indium tin oxide, the material of the fourth electrode is indium zinc oxide, the material of the second electrode is magnesium silver alloy, and the material of the third electrode is aluminum;

[0032] The thickness of the first electrode ranges from 60 nanometers to 80 nanometers; the thickness of the fourth electrode ranges from 10 nanometers to 30 nanometers; the thickness of the second electrode ranges from 5 nanometers to 25 nanometers; and the thickness of the third electrode ranges from 80 nanometers to 120 nanometers.

[0033] Optionally, the thickness of the first light-emitting layer ranges from 30 nanometers to 50 nanometers; the thickness of the third light-emitting layer ranges from 25 nanometers to 40 nanometers.

[0034] Optionally, the light-emitting device further comprises: a third electroluminescent unit and a fourth electrode located on a side of the third electrode away from the substrate; wherein the potential of the fourth electrode is lower than the potential of the third electrode;

[0035] The third electroluminescent unit includes: a third hole transport layer, a third light-emitting layer and a third electron transport layer stacked in sequence in a direction away from the base substrate.

[0036] Optionally, the work function of the material of the first electrode is greater than the work function of the material of the second electrode, greater than the work function of the material of the third electrode, and greater than the work function of the material of the fourth electrode;

[0037] A work function of the third electrode is greater than a work function of the second electrode and greater than a work function of the fourth electrode.

[0038] Optionally, the material of the first electrode is indium tin oxide, the material of the second electrode is magnesium silver alloy, the material of the third electrode is indium zinc oxide, and the material of the fourth electrode is aluminum;

[0039] The thickness of the first electrode ranges from 60 nanometers to 80 nanometers; the thickness of the second electrode ranges from 10 nanometers to 30 nanometers; the thickness of the third electrode ranges from 5 nanometers to 25 nanometers; and the thickness of the fourth electrode ranges from 80 nanometers to 120 nanometers.

[0040] Optionally, the first electroluminescent unit is a red electroluminescent unit, and the second electroluminescent unit is a green electroluminescent unit.

[0041] On the other hand, a display panel is provided, comprising: a base substrate and a plurality of light-emitting devices as described above located on one side of the base substrate.

[0042] In another aspect, a display device is provided, comprising: a power supply component and the display panel according to the above aspect;

[0043] Wherein, the power supply component is used to supply power to the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] 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.

[0045] FIG1 is a schematic structural diagram of a light-emitting device provided in an embodiment of the present application;

[0046] FIG2 is a schematic structural diagram of another light-emitting device provided in an embodiment of the present application;

[0047] FIG3 is a schematic structural diagram of another light-emitting device provided in an embodiment of the present application;

[0048] FIG4 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0049] FIG5 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0050] FIG6 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0051] FIG7 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0052] FIG8 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0053] FIG9 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0054] FIG10 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0055] FIG11 is a schematic structural diagram of another light-emitting device provided in an embodiment of the present application;

[0056] FIG12 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application;

[0057] FIG13 is a schematic structural diagram of a display panel provided in an embodiment of the present application;

[0058] FIG14 is a schematic structural diagram of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0060] In related art, a display panel includes multiple light-emitting devices, which can be organic light-emitting diodes (OLEDs). These devices may have an anode, a cathode, and an electroluminescent unit located between the anode and cathode. Driven by an external voltage, holes and electrons are injected from the anode and cathode, respectively, into the organic light-emitting film layer in the electroluminescent unit, thereby forming excitons in the organic light-emitting film layer and radiating light.

[0061] However, the optical performance of the light-emitting device in the related art is poor, which in turn leads to poor display effect of the display panel.

[0062] FIG1 is a schematic diagram of the structure of a light emitting device provided in an embodiment of the present application. Referring to FIG1 , the light emitting device 10 includes a first electrode 101 , a first electroluminescent unit 102 , a second electrode 103 , a second electroluminescent unit 104 , and a third electrode 105 , which are stacked in sequence on a substrate 20 .

[0063] The first electroluminescent unit 102 can emit light under the combined action of the first electrode 101 and the second electrode 103, and the second electroluminescent unit 104 can emit light under the combined action of the second electrode 103 and the third electrode 105. The color of the light emitted by the first electroluminescent unit 102 is different from the color of the light emitted by the second electroluminescent unit 104. Optionally, the color of the light emitted by the first electroluminescent unit 102 is red, i.e., the first electroluminescent unit 102 is a red electroluminescent unit, and the color of the light emitted by the second electroluminescent unit 104 is green, i.e., the second electroluminescent unit 104 is a green electroluminescent unit.

[0064] In the embodiment of the present application, the potential of the first electrode 101 can be higher than the potential of the second electrode 103 and higher than the potential of the third electrode 105. The potential of the second electrode 103 is different from the potential of the third electrode 105. In other words, the potential of the second electrode 103 can be greater than the potential of the third electrode 105, or it can be less than the potential of the third electrode 105.

[0065] For the first electroluminescent unit 102, the first electrode 101 can serve as the anode of the first electroluminescent unit 102, and the second electrode 103 can serve as the cathode of the first electroluminescent unit 102. Driven by an external driving voltage, electrons from the second electrode 103 and holes from the first electrode 101 respectively move into the light-emitting layer of the first electroluminescent unit 102. When the holes and electrons meet in the light-emitting layer of the first electroluminescent unit 102, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0066] For the second electroluminescent unit 104, assuming the potential of the second electrode 103 is greater than that of the third electrode 105, the second electrode 103 can serve as the anode of the second electroluminescent unit 104, and the third electrode 105 can serve as the cathode of the second electroluminescent unit 104. Driven by an external driving voltage, electrons from the third electrode 105 and holes from the second electrode 103 respectively migrate to the light-emitting layer of the second electroluminescent unit 104. When the holes and electrons meet in the light-emitting layer of the second electroluminescent unit 104, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0067] For the second electroluminescent unit 104, assuming the potential of the second electrode 103 is lower than that of the third electrode 105, the second electrode 103 can serve as the cathode of the second electroluminescent unit 104, and the third electrode 105 can serve as the anode of the second electroluminescent unit 104. Driven by an external driving voltage, electrons from the second electrode 103 and holes from the third electrode 105 respectively migrate to the light-emitting layer of the second electroluminescent unit 104. When the holes and electrons meet in the light-emitting layer of the second electroluminescent unit 104, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0068] In the embodiment of the present application, the reflectivity of at least one of the second electrode 103 and the third electrode 105 is greater than 10%, for example, the reflectivity of at least one electrode is 20%. As a result, the light emitted by the first electroluminescent unit 102 and the light emitted by the second electroluminescent unit 104 can be reflected at the electrode with a higher reflectivity, thereby increasing the interference effect of the light, improving the microcavity strength of the light-emitting device, and thus improving the optical performance of the light-emitting device 10 and the brightness of the display panel.

[0069] In summary, the embodiments of the present application provide a light-emitting device, which includes a first electrode, a first electroluminescent unit, a second electrode, a second electroluminescent unit, and a third electrode, which are located on a substrate and stacked in sequence. The first electroluminescent unit can emit light under the joint action of the first electrode and the second electrode, and the second electroluminescent unit can emit light under the joint action of the second electrode and the third electrode. Since at least one of the second electrode and the third electrode has a high reflectivity, the light emitted by the first electroluminescent unit and the light emitted by the second electroluminescent unit can be reflected at the electrode with the higher reflectivity, thereby increasing the interference effect of the light, improving the microcavity strength of the light-emitting device, and thus improving the optical performance of the light-emitting device and the brightness of the display panel.

[0070] As an optional implementation, the potential of the second electrode 103 is higher than the potential of the third electrode 105. That is, the first electroluminescent unit 102 and the second electroluminescent unit 104 are both upright light-emitting units. Referring to FIG2 , the first electroluminescent unit 102 includes: a first hole transport layer 1021, a first light-emitting layer 1022, and a first electron transport layer 1023, stacked in sequence in a direction away from the substrate 20. The second electroluminescent unit 104 includes: a second hole transport layer 1041, a second light-emitting layer 1042, and a second electron transport layer 1043, stacked in sequence in a direction away from the substrate 20.

[0071] Optionally, for any electroluminescent unit, if the work function of the material of the anode of the electroluminescent unit is greater than the work function of the material of the cathode, it is easier for the driving circuit to provide appropriate driving voltages to the two electrodes to make the electroluminescent unit emit light.

[0072] Therefore, since the potential of the first electrode 101 is higher than that of the second electrode 103, the first electrode 101 acts as an anode and the second electrode 103 acts as a cathode for the first electroluminescent unit 102. Furthermore, if the work function of the material of the first electrode 101 is greater than the work function of the material of the second electrode 103, it is easier for the first electroluminescent unit 102 to emit light.

[0073] Since the potential of the second electrode 103 is higher than that of the third electrode 105, the second electrode 103 acts as an anode and the third electrode 105 acts as a cathode for the second electroluminescent unit 104. Furthermore, if the work function of the material of the second electrode 103 is greater than the work function of the material of the third electrode 105, it is easier for the second electroluminescent unit 104 to emit light.

[0074] Furthermore, since the work function of the material of the first electrode 101 is greater than the work function of the material of the second electrode 103 , and the work function of the material of the second electrode 103 is greater than the work function of the material of the third electrode 105 , the work function of the material of the first electrode 101 is also greater than the work function of the material of the third electrode 105 .

[0075] Optionally, the material of the first electrode 101 may be indium tin oxide, the material of the second electrode 103 may be aluminum, and the material of the third electrode 105 may be a magnesium-silver alloy. Referring to FIG3 , the thickness of the first electrode 101 ranges from 60 nm (nanometers) to 80 nm, the thickness of the second electrode 103 ranges from 10 nm to 30 nm, and the thickness of the third electrode 105 ranges from 80 nm to 120 nm.

[0076] 3 , the thickness of the first hole transport layer 1021 ranges from 170 nm to 210 nm, the thickness of the first light-emitting layer 1022 ranges from 20 nm to 40 nm, and the thickness of the first electron transport layer 1023 ranges from 30 nm to 60 nm. The thickness of the second hole transport layer 1041 ranges from 340 nm to 370 nm, the thickness of the second light-emitting layer 1042 ranges from 30 nm to 50 nm, and the thickness of the second electron transport layer 1043 ranges from 30 nm to 50 nm.

[0077] That is, in the schemes shown in Figures 2 and 3, since the reflectivity of the second electrode 103 (aluminum) is relatively high, but the reflectivity of the first electrode 101 (indium tin oxide) is relatively low, the first electroluminescent unit 102 can be an electroluminescent unit with a weak microcavity. Since the reflectivity of the third electrode 105 (magnesium-silver alloy) and the second electrode 103 (aluminum) are both relatively high, the second electroluminescent unit 104 can be an electroluminescent unit with a strong microcavity.

[0078] As a result, the light emitted by the second electroluminescent unit 104 can be reflected multiple times between the second electrode 103 and the third electrode 105, increasing the interference effect of the reflected light. Although the first electroluminescent unit 102 is a weak microcavity electroluminescent unit, the light emitted by the first electroluminescent unit 102 can be partially reflected by the second electrode 103 and the third electrode 105, increasing the interference effect and improving optical efficiency. As a result, the performance of the light-emitting device is improved, and the brightness of the product can also be increased. At the same brightness, the current efficiency is reduced, and the lifespan can be improved.

[0079] Furthermore, referring to FIG4 , the light-emitting device 10 further includes: a fourth electrode 106 and a third electroluminescent unit 107 located between the first electroluminescent unit 102 and the second electrode 103. The potential of the fourth electrode 106 is lower than that of the first electrode 101 and higher than that of the second electrode 103. The third electroluminescent unit 107 can be an upright electroluminescent unit. Optionally, referring to FIG4 , the third electroluminescent unit 107 includes: a third hole transport layer 1071, a third light-emitting layer 1072, and a third electron transport layer 1073, stacked sequentially in a direction away from the substrate 20.

[0080] For the first electroluminescent unit 102, the first electrode 101 can serve as the anode of the first electroluminescent unit 102, and the fourth electrode 106 can serve as the cathode of the first electroluminescent unit 102. Driven by an external driving voltage (i.e., a positive voltage is applied to the first electrode 101 and a negative voltage is applied to the fourth electrode), electrons from the fourth electrode 106 and holes from the first electrode 101 respectively move into the light-emitting layer of the first electroluminescent unit 102. When the holes and electrons meet in the light-emitting layer of the first electroluminescent unit 102, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0081] For the third electroluminescent unit 107, the fourth electrode 106 can serve as the anode of the third electroluminescent unit 107, and the second electrode 103 can serve as the cathode of the third electroluminescent unit 107. Driven by an external driving voltage (i.e., a positive voltage applied to the fourth electrode 106 and a negative voltage applied to the second electrode 103), electrons from the second electrode 103 and holes from the fourth electrode 106 respectively migrate to the light-emitting layer of the third electroluminescent unit 107. When the holes and electrons meet in the light-emitting layer of the third electroluminescent unit 107, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0082] For the second electroluminescent unit 104, the second electrode 103 can serve as the anode of the second electroluminescent unit 104, and the third electrode 105 can serve as the cathode of the second electroluminescent unit 104. Driven by an external driving voltage (i.e., a positive voltage is applied to the second electrode 103 and a negative voltage is applied to the third electrode 105), electrons from the third electrode 105 and holes from the second electrode 103 respectively migrate to the light-emitting layer of the third electroluminescent unit 107. When the holes and electrons meet in the light-emitting layer of the second electroluminescent unit 104, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0083] Since the potential of the first electrode 101 is higher than that of the fourth electrode 106, the first electrode 101 acts as an anode and the fourth electrode 106 acts as a cathode for the first electroluminescent unit 102. Furthermore, if the work function of the material of the first electrode 101 is greater than the work function of the material of the fourth electrode 106, it is easier for the first electroluminescent unit 102 to emit light.

[0084] Since the potential of the fourth electrode 106 is higher than that of the second electrode 103, the fourth electrode 106 serves as an anode and the second electrode 103 serves as a cathode for the third electroluminescent unit 107. Furthermore, if the work function of the material of the fourth electrode 106 is greater than the work function of the material of the second electrode 103, it is easier for the third electroluminescent unit 107 to emit light.

[0085] Since the potential of the second electrode 103 is higher than that of the third electrode 105, the second electrode 103 acts as an anode and the third electrode 105 acts as a cathode for the second electroluminescent unit 104. Furthermore, if the work function of the material of the second electrode 103 is greater than the work function of the material of the third electrode 105, it is easier for the second electroluminescent unit 104 to emit light.

[0086] Moreover, since the work function of the material of the first electrode 101 is greater than the work function of the material of the fourth electrode 106, the work function of the material of the fourth electrode 106 is greater than the work function of the material of the second electrode 103, and the work function of the material of the second electrode 103 is greater than the work function of the material of the third electrode 105, the work function of the material of the first electrode 101 is also greater than the work function of the material of the second electrode 103, and greater than the work function of the material of the third electrode 105, and the work function of the material of the fourth electrode 106 is greater than the work function of the material of the third electrode 105.

[0087] Optionally, the material of the first electrode 101 may be indium tin oxide, the material of the fourth electrode 106 may be indium zinc oxide, the material of the second electrode 103 may be aluminum, and the material of the third electrode 105 may be a magnesium-silver alloy. Referring to FIG5 , the thickness of the first electrode 101 ranges from 60 nm to 80 nm, the thickness of the fourth electrode 106 ranges from 10 nm to 30 nm, the thickness of the second electrode 103 ranges from 10 nm to 30 nm, and the thickness of the third electrode 105 ranges from 80 nm to 120 nm.

[0088] In addition, the thickness of the first hole transport layer 1021 ranges from 170 nm to 210 nm, the thickness of the first light-emitting layer 1022 ranges from 20 nm to 40 nm, and the thickness of the first electron transport layer 1043 ranges from 35 nm to 55 nm. The thickness of the third hole transport layer 1071 ranges from 145 nm to 160 nm, the thickness of the third light-emitting layer 1072 ranges from 15 nm to 35 nm, and the thickness of the third electron transport layer 1073 ranges from 105 nm to 125 nm. The thickness of the second hole transport layer 1041 ranges from 30 nm to 50 nm, the thickness of the second light-emitting layer 1042 ranges from 30 nm to 50 nm, and the thickness of the second electron transport layer 1043 ranges from 75 nm to 95 nm.

[0089] That is, in the schemes shown in Figures 4 and 5, since the reflectivity of the first electrode 101 and the reflectivity of the fourth electrode 106 are both relatively low, the first electroluminescent unit 102 is a weak microcavity electroluminescent unit. Since the reflectivity of the second electrode 103 (aluminum) is relatively high, but the reflectivity of the fourth electrode 106 (indium zinc oxide) is relatively low, the third electroluminescent unit 107 can be a weak microcavity electroluminescent unit. Since the reflectivity of the second electrode 103 (aluminum) and the third electrode 105 (magnesium silver alloy) are both relatively high, the second electroluminescent unit 104 can be a strong microcavity electroluminescent unit.

[0090] As a result, the light emitted by the second electroluminescent unit 104 can be reflected multiple times between the second electrode 103 and the third electrode 105, increasing the interference effect of the reflected light. Although the first electroluminescent unit 102 and the third electroluminescent unit 107 are weak microcavity electroluminescent units, the light emitted by the first electroluminescent unit 102 and the third electroluminescent unit 107 can be partially reflected by the second electrode 103 and the third electrode 105, increasing the interference effect and improving the optical efficiency. As a result, the performance of the light-emitting device is improved, and the brightness of the product can also be increased. At the same brightness, the current efficiency is reduced, and the lifespan can be improved.

[0091] Since the material of the second electrode 103 is aluminum (metal material), in order to ensure that the second electroluminescent unit 104 located between the second electrode 103 and the third electrode 105 can emit light through the second electrode 103, the second electrode 103 needs to have a certain transmittance, but at the same time needs to have a certain reflectivity to ensure the interference effect of light.

[0092] Typically, the transmittance of the second electrode 103 is negatively correlated with the thickness of the second electrode 103, and the reflectance of the second electrode 103 is positively correlated with the thickness of the second electrode 103. That is, the smaller the thickness of the second electrode 103, the greater the transmittance and the lower the reflectance of the second electrode 103; and the thicker the second electrode 103, the lower the transmittance and the greater the reflectance of the second electrode 103.

[0093] Therefore, in order to ensure that the transmittance and reflectivity of the second electrode 103 meet certain requirements, the thickness of the second electrode 103 can be set in a range of 10 nm to 30 nm.

[0094] As another optional implementation, the potential of the third electrode 105 is higher than the potential of the second electrode 103. That is, the first electroluminescent unit 102 is an upright light-emitting unit, and the second electroluminescent unit 104 is an inverted light-emitting unit. Referring to FIG6 , the first electroluminescent unit 102 includes: a first hole transport layer 1021, a first light-emitting layer 1022, and a first electron transport layer 1023, stacked in sequence in a direction away from the base substrate 20. The second electroluminescent unit 104 includes: a second electron transport layer 1043, a second light-emitting layer 1042, and a second hole transport layer 1041, stacked in sequence in a direction away from the base substrate 20.

[0095] Optionally, for any electroluminescent unit, if the work function of the material of the anode of the electroluminescent unit is greater than the work function of the material of the cathode, it is easier for the driving circuit to provide appropriate driving voltages to the two electrodes to make the electroluminescent unit emit light.

[0096] Therefore, since the potential of the first electrode 101 is higher than that of the second electrode 103, the first electrode 101 acts as an anode and the second electrode 103 acts as a cathode for the first electroluminescent unit 102. Furthermore, if the work function of the material of the first electrode 101 is greater than the work function of the material of the second electrode 103, it is easier for the first electroluminescent unit 102 to emit light.

[0097] Since the potential of the third electrode 105 is higher than that of the second electrode 103, the second electrode 103 acts as a cathode and the third electrode 105 acts as an anode for the second electroluminescent unit 104. Furthermore, if the work function of the material of the third electrode 105 is greater than the work function of the material of the second electrode 103, it is easier for the second electroluminescent unit 104 to emit light.

[0098] In addition, the work function of the material of the first electrode 101 may also be greater than the work function of the material of the third electrode 105 .

[0099] Optionally, the material of the first electrode 101 may be indium tin oxide, the material of the second electrode 103 may be a magnesium silver alloy, and the material of the third electrode 105 may be aluminum. Referring to FIG7 , the thickness of the first electrode 101 ranges from 60 nm to 80 nm, the thickness of the second electrode 103 ranges from 10 nm to 40 nm, and the thickness of the third electrode 105 ranges from 90 nm to 110 nm.

[0100] In addition, the thickness of the first hole transport layer 1021 ranges from 170 nm to 210 nm, the thickness of the first light-emitting layer 1022 ranges from 20 nm to 40 nm, and the thickness of the first electron transport layer 1023 ranges from 30 nm to 60 nm. The thickness of the second electron transport layer 1043 ranges from 340 nm to 370 nm, the thickness of the second light-emitting layer 1042 ranges from 30 nm to 50 nm, and the thickness of the second hole transport layer 1041 ranges from 30 nm to 50 nm.

[0101] That is, in the schemes shown in Figures 6 and 7, since the reflectivity of the second electrode 103 (magnesium-silver alloy) is relatively high, but the reflectivity of the first electrode 101 (indium tin oxide) is relatively low, the first electroluminescent unit 102 can be an electroluminescent unit with a weak microcavity. Since the reflectivity of both the third electrode 105 (aluminum) and the second electrode 103 (magnesium-silver alloy) is relatively high, the second electroluminescent unit 104 can be an electroluminescent unit with a strong microcavity.

[0102] As a result, the light emitted by the second electroluminescent unit 104 can be reflected multiple times between the second electrode 103 and the third electrode 105, increasing the interference effect of the reflected light. Although the first electroluminescent unit 102 is a weak microcavity electroluminescent unit, the light emitted by the first electroluminescent unit 102 can be partially reflected by the second electrode 103 and the third electrode 105, increasing the interference effect and improving optical efficiency. As a result, the performance of the light-emitting device is improved, and the brightness of the product can also be increased. At the same brightness, the current efficiency is reduced, and the lifespan can be improved.

[0103] Furthermore, referring to FIG8 , the light-emitting device 10 further includes: a fourth electrode 106 and a third electroluminescent unit 107 located between the first electroluminescent unit 102 and the second electrode 103. The potential of the fourth electrode 106 is lower than that of the first electrode 101 and higher than that of the second electrode 103. The third electroluminescent unit 107 can be an upright electroluminescent unit. Optionally, referring to FIG8 , the third electroluminescent unit 107 includes: a third hole transport layer 1071, a third light-emitting layer 1072, and a third electron transport layer 1073, stacked sequentially in a direction away from the substrate 20.

[0104] For the first electroluminescent unit 102, the first electrode 101 can serve as the anode of the first electroluminescent unit 102, and the fourth electrode 106 can serve as the cathode of the first electroluminescent unit 102. Driven by an external driving voltage (i.e., a positive voltage is applied to the first electrode 101 and a negative voltage is applied to the fourth electrode 106), electrons from the fourth electrode 106 and holes from the first electrode 101 respectively move into the light-emitting layer of the first electroluminescent unit 102. When the holes and electrons meet in the light-emitting layer of the first electroluminescent unit 102, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0105] For the third electroluminescent unit 107, the fourth electrode 106 can serve as the anode of the third electroluminescent unit 107, and the second electrode 103 can serve as the cathode of the third electroluminescent unit 107. Driven by an external driving voltage (i.e., a positive voltage is applied to the fourth electrode 106 and a negative voltage is applied to the second electrode 103), electrons from the second electrode 103 and holes from the fourth electrode 106 respectively migrate to the light-emitting layer of the third electroluminescent unit 107. When the holes and electrons meet in the light-emitting layer of the third electroluminescent unit 107, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0106] For the second electroluminescent unit 104, the second electrode 103 can serve as the cathode of the second electroluminescent unit 104, and the third electrode 105 can serve as the anode of the second electroluminescent unit 104. Driven by an external driving voltage (i.e., a negative voltage is applied to the second electrode 103 and a positive voltage is applied to the third electrode 105), electrons from the second electrode 103 and holes from the third electrode 105 respectively migrate to the light-emitting layer of the third electroluminescent unit 107. When the holes and electrons meet in the light-emitting layer of the second electroluminescent unit 104, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0107] Since the potential of the first electrode 101 is higher than that of the fourth electrode 106, the first electrode 101 acts as an anode and the fourth electrode 106 acts as a cathode for the first electroluminescent unit 102. Furthermore, if the work function of the material of the first electrode 101 is greater than the work function of the material of the fourth electrode 106, it is easier for the first electroluminescent unit 102 to emit light.

[0108] Since the potential of the fourth electrode 106 is higher than that of the second electrode 103, the fourth electrode 106 serves as an anode and the second electrode 103 serves as a cathode for the third electroluminescent unit 107. Furthermore, if the work function of the material of the fourth electrode 106 is greater than the work function of the material of the second electrode 103, it is easier for the third electroluminescent unit 107 to emit light.

[0109] Since the potential of the third electrode 105 is higher than that of the second electrode 103, the second electrode 103 acts as a cathode and the third electrode 105 acts as an anode for the second electroluminescent unit 104. Furthermore, if the work function of the material of the third electrode 105 is greater than the work function of the material of the second electrode 103, it is easier for the second electroluminescent unit 104 to emit light.

[0110] Furthermore, because the work function of the material of the first electrode 101 is greater than the work function of the material of the fourth electrode 106, the work function of the material of the fourth electrode 106 is greater than the work function of the material of the second electrode 103, and the work function of the material of the third electrode 105 is greater than the work function of the material of the second electrode 103, the work function of the material of the first electrode 101 is also greater than the work function of the material of the second electrode 103. Furthermore, the work function of the material of the first electrode 101 and the work function of the material of the fourth electrode 106 may also be greater than the work function of the material of the third electrode 105.

[0111] Optionally, the material of the first electrode 101 may be indium tin oxide, the material of the fourth electrode 106 may be indium zinc oxide, the material of the second electrode 103 may be a magnesium silver alloy, and the material of the third electrode 105 may be aluminum. Referring to FIG9 , the thickness of the first electrode 101 ranges from 60 nm to 80 nm, the thickness of the fourth electrode 106 ranges from 10 nm to 30 nm, the thickness of the second electrode 103 ranges from 5 nm to 25 nm, and the thickness of the third electrode 105 ranges from 80 nm to 120 nm.

[0112] 9 , the thickness of the first hole transport layer 1021 ranges from 170 nm to 210 nm, the thickness of the first light-emitting layer 1022 ranges from 20 nm to 40 nm, and the thickness of the first electron transport layer 1043 ranges from 35 nm to 55 nm. The thickness of the third hole transport layer 1071 ranges from 135 nm to 150 nm, the thickness of the third light-emitting layer 1072 ranges from 15 nm to 35 nm, and the thickness of the third electron transport layer 1073 ranges from 115 nm to 135 nm. The thickness of the second electron transport layer 1043 ranges from 150 nm to 170 nm, the thickness of the second light-emitting layer 1042 ranges from 30 nm to 50 nm, and the thickness of the second hole transport layer 1041 ranges from 50 nm to 80 nm.

[0113] That is, in the schemes shown in Figures 8 and 9, since the reflectivity of the first electrode 101 and the reflectivity of the fourth electrode 106 are both relatively low, the first electroluminescent unit 102 is a weak microcavity electroluminescent unit. Since the reflectivity of the second electrode 103 (magnesium-silver alloy) is relatively high, but the reflectivity of the fourth electrode 106 (indium zinc oxide) is relatively low, the third electroluminescent unit 107 can be a weak microcavity electroluminescent unit. Since the reflectivity of the second electrode 103 (magnesium-silver alloy) and the third electrode 105 (aluminum) are both relatively high, the second electroluminescent unit 104 can be a strong microcavity electroluminescent unit.

[0114] As a result, the light emitted by the second electroluminescent unit 104 can be reflected multiple times between the second electrode 103 and the third electrode 105, increasing the interference effect of the reflected light. Although the first electroluminescent unit 102 and the third electroluminescent unit 107 are weak microcavity electroluminescent units, the light emitted by the first electroluminescent unit 102 and the third electroluminescent unit 107 can be partially reflected by the second electrode 103 and the third electrode 105, increasing the interference effect and improving the optical efficiency. As a result, the performance of the light-emitting device is improved, and the brightness of the product can also be increased. At the same brightness, the current efficiency is reduced, and the lifespan can be improved.

[0115] Optionally, taking the first electroluminescent unit as a red electroluminescent unit, the second electroluminescent unit as a blue electroluminescent unit, and the third electroluminescent unit as a green electroluminescent unit as an example, refer to Table 1, which shows the current efficiency and color point of each electroluminescent unit in the light-emitting device shown in FIG8 .

[0116] Table 1

[0117] For blue electroluminescent cells, current efficiency and color point (CIE y) jointly influence device performance. Therefore, to measure the performance of a blue electroluminescent cell, both current efficiency and color point (CIE y) must be considered to obtain the BI value. The BI value is equal to current efficiency divided by color point (CIE y). For example, in Table 1 above, the BI value of the blue electroluminescent cell is 6.46 ÷ 0.0557 = 115.9785.

[0118] In addition, it can be seen from Table 1 above that the color point (CIE x) and the color point (CIE y) of each electroluminescent unit have little difference from the standard color point and can meet the corresponding luminescence requirements.

[0119] Assuming that the reflectivity of the second electrode and the third electrode are both low (conventional light-emitting device), the current efficiency and color point of each electroluminescent unit in the light-emitting device are obtained as shown in Table 2 below.

[0120] Table 2

[0121] From Table 1 and Table 2 above, it can be seen that, compared with conventional light-emitting devices, the efficiency of the red electroluminescent unit of the light-emitting device in the present application is improved by: (14.29-11.34) / 11.34=26%, the efficiency of the green electroluminescent unit is improved by: (68.4-52.46) / 52.46=30%, and the BI value of the blue electroluminescent unit is improved by: (115.9785-94.14) / 94.14=23%.

[0122] In the embodiment of the present application, due to the strong drilling and penetration ability of indium zinc oxide (fourth electrode 106), indium zinc oxide (fourth electrode 106) may be directly connected to other electrodes above and below, causing a short circuit in the device. In order to solve the above problem, the light-emitting layers before and after the fourth electrode 106 (i.e., the first light-emitting layer and the third light-emitting layer) can be thickened, and the device structure can be optically adjusted to form a thickened device structure as shown in Figure 10. Combining Table 3 and Table 2, in the performance of the thickened device, the efficiency of the red electroluminescent unit is improved by: (11.34-11.34) / 11.34=0%, the efficiency of the green electroluminescent unit is improved by: (65.78-52.46) / 52.46=25%, and the BI value of the blue electroluminescent unit is improved by: (100.6745-94.14) / 94.14=7%. That is, the performance of the thickened device is lower than that of the non-thickened device to a certain extent, but it is still improved compared to the conventional device.

[0123] Table 3

[0124] Furthermore, referring to FIG11 , the light-emitting device 10 further includes a third electroluminescent unit 107 and a fourth electrode 106 located on a side of the third electrode 105 away from the substrate 20. The potential of the fourth electrode 106 is lower than that of the third electrode 105. The third electroluminescent unit 107 may be an upright electroluminescent unit. Optionally, referring to FIG11 , the third electroluminescent unit 107 includes a third hole transport layer 1071, a third light-emitting layer 1072, and a third electron transport layer 1073, stacked sequentially in a direction away from the substrate 20.

[0125] For the first electroluminescent unit 102, the first electrode 101 can serve as the anode of the first electroluminescent unit 102, and the second electrode 103 can serve as the cathode of the first electroluminescent unit 102. Driven by an external driving voltage (i.e., a positive voltage is applied to the first electrode 101 and a negative voltage is applied to the second electrode 103), electrons from the second electrode 103 and holes from the first electrode 101 respectively move into the light-emitting layer of the first electroluminescent unit 102. When the holes and electrons meet in the light-emitting layer of the first electroluminescent unit 102, energy excitons are generated, which excite the light-emitting molecules and ultimately produce visible light.

[0126] For the second electroluminescent unit 104, the second electrode 103 can serve as the cathode of the second electroluminescent unit 104, and the third electrode 105 can serve as the anode of the second electroluminescent unit 104. Driven by an external driving voltage (i.e., a negative voltage is applied to the second electrode 103 and a positive voltage is applied to the third electrode 105), electrons from the second electrode 103 and holes from the third electrode 105 respectively migrate to the light-emitting layer of the second electroluminescent unit 104. When the holes and electrons meet in the light-emitting layer of the second electroluminescent unit 104, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0127] For the third electroluminescent unit 107, the third electrode 105 can serve as the anode of the third electroluminescent unit 107, and the fourth electrode 106 can serve as the cathode of the third electroluminescent unit 107. Driven by an external driving voltage (i.e., a positive voltage is applied to the third electrode 105 and a negative voltage is applied to the fourth electrode 106), electrons from the fourth electrode 106 and holes from the third electrode 105 respectively migrate to the light-emitting layer of the third electroluminescent unit 107. When the holes and electrons meet in the light-emitting layer of the third electroluminescent unit 107, energy excitons are generated, which excite the luminescent molecules and ultimately produce visible light.

[0128] Since the potential of the first electrode 101 is higher than that of the second electrode 103, the first electrode 101 acts as an anode and the second electrode 103 acts as a cathode for the first electroluminescent unit 102. Furthermore, if the work function of the material of the first electrode 101 is greater than the work function of the material of the second electrode 103, it is easier for the first electroluminescent unit 102 to emit light.

[0129] Since the potential of the third electrode 105 is higher than that of the second electrode 103, the second electrode 103 acts as a cathode and the third electrode 105 acts as an anode for the second electroluminescent unit 104. Furthermore, if the work function of the material of the third electrode 105 is greater than the work function of the material of the second electrode 103, it is easier for the second electroluminescent unit 104 to emit light.

[0130] Since the potential of the third electrode 105 is higher than that of the fourth electrode 106, the third electrode 105 acts as an anode and the fourth electrode 106 acts as a cathode for the third electroluminescent unit 107. Furthermore, if the work function of the material of the third electrode 105 is greater than the work function of the material of the fourth electrode 106, it is easier for the third electroluminescent unit 107 to emit light.

[0131] Furthermore, the work function of the material of the first electrode 101 may be greater than the work function of the material of the third electrode 105 , and greater than the work function of the material of the fourth electrode 106 .

[0132] Optionally, the material of the first electrode 101 may be indium tin oxide, the material of the second electrode 103 may be a magnesium-silver alloy, the material of the third electrode 105 may be indium zinc oxide, and the material of the fourth electrode 106 may be aluminum. Referring to FIG12 , the thickness of the first electrode 101 ranges from 60 nm to 80 nm, the thickness of the second electrode 103 ranges from 10 nm to 30 nm, the thickness of the third electrode 105 ranges from 5 nm to 25 nm, and the thickness of the fourth electrode 106 ranges from 80 nm to 120 nm.

[0133] 12 , the thickness of the first hole transport layer 1021 ranges from 170 nm to 210 nm, the thickness of the first light-emitting layer 1022 ranges from 20 nm to 40 nm, and the thickness of the first electron transport layer 1043 ranges from 35 nm to 55 nm. The thickness of the second electron transport layer 1043 ranges from 135 nm to 150 nm, the thickness of the second light-emitting layer 1042 ranges from 15 nm to 35 nm, and the thickness of the second hole transport layer 1041 ranges from 115 nm to 135 nm. The thickness of the third hole transport layer 1071 ranges from 70 nm to 90 nm, the thickness of the third light-emitting layer 1072 ranges from 30 nm to 50 nm, and the thickness of the third electron transport layer 1073 ranges from 50 nm to 80 nm.

[0134] That is, in the schemes shown in Figures 11 and 12, since the reflectivity of the second electrode 103 (magnesium-silver alloy) is relatively high, but the reflectivity of the first electrode 101 (indium tin oxide) is relatively low, the first electroluminescent unit 102 is a weak microcavity electroluminescent unit. Since the reflectivity of the second electrode 103 (magnesium-silver alloy) is relatively high, but the reflectivity of the third electrode 105 (indium zinc oxide) is relatively low, the second electroluminescent unit 104 can be a weak microcavity electroluminescent unit. Since the reflectivity of both the third electrode 105 (indium zinc oxide) and the fourth electrode 106 (aluminum) is relatively high, the third electroluminescent unit 107 can be a strong microcavity electroluminescent unit.

[0135] Therefore, in the solutions shown in Figures 11 and 12, the first electroluminescent unit 102, the second electroluminescent unit 104, and the third electroluminescent unit 107 are all weak microcavity electroluminescent units. However, the light emitted by each electroluminescent unit can be partially reflected by the second electrode 103 and the fourth electrode 106, which increases the interference effect and improves the optical efficiency. As a result, the performance of the light-emitting device is improved, the brightness of the product can also be increased, the current efficiency is reduced at the same brightness, and the lifespan can be increased.

[0136] In the embodiment of the present application, the first electroluminescent unit 102 may be a red electroluminescent unit, the second electroluminescent unit 104 may be a green electroluminescent unit, and the third electroluminescent unit 107 may be a blue electroluminescent unit.

[0137] In the solutions shown in Figures 2 and 6, the light-emitting device can be a yellow-light stacked device composed of red and green electroluminescent units. Optionally, the yellow-light stacked device can be used in fields such as medical care and space exploration. Yellow-light lamps, also known as UV-free lamps, direct-light-proof lamps, or UV-resistant lamps, are widely used in yellow-light areas of electronics factories, museums, art galleries, archives, libraries, art galleries, high-end boutique showrooms, color matching inspections of printed materials, and antique and cultural relic storage. Furthermore, the yellow-light stacked device can be used in locations where photosensitive materials are stored, including integrated circuit (IC) semiconductor electronics factories, plasma night crystal panel factories, laptop computers (Natebooks), personal digital assistants (PDAs), digital cameras, thin film transistors (TFTs), super twisted nematic (STN) screens, OLED mobile phone manufacturers, R&D laboratories, and clean rooms.

[0138] In the solutions shown in FIG. 4 , FIG. 8 and FIG. 11 , the light emitting device may be a white light stacked device consisting of a red electroluminescent unit, a green electroluminescent unit and a blue electroluminescent unit.

[0139] In summary, the embodiments of the present application provide a light-emitting device, which includes a first electrode, a first electroluminescent unit, a second electrode, a second electroluminescent unit, and a third electrode, which are located on a substrate and stacked in sequence. The first electroluminescent unit can emit light under the joint action of the first electrode and the second electrode, and the second electroluminescent unit can emit light under the joint action of the second electrode and the third electrode. Since at least one of the second electrode and the third electrode has a high reflectivity, the light emitted by the first electroluminescent unit and the light emitted by the second electroluminescent unit can be reflected at the electrode with the higher reflectivity, thereby increasing the interference effect of the light, improving the microcavity strength of the light-emitting device, and thus improving the optical performance of the light-emitting device and the brightness of the display panel.

[0140] FIG13 is a schematic diagram of the structure of a display panel provided in an embodiment of the present application. Referring to FIG13 , the display panel 01 includes a base substrate 20 and a plurality of light-emitting devices 10 provided in the above embodiment located on one side of the base substrate 20. FIG13 schematically shows only one light-emitting device 10.

[0141] Optionally, the display panel 01 further includes an encapsulation layer 30, a filler layer 40, and a cover plate 50 located on a side of the light emitting device 10 away from the base substrate 20. The encapsulation layer 30 may be made of SiON (silicon oxynitride), and the cover plate 50 may be made of glass.

[0142] Optionally, the thickness of the encapsulation layer 30 ranges from 900 to 1100 nm, and the thickness of the filling layer 40 ranges from 8900 nm to 9100 nm.

[0143] Since the display panel can have substantially the same technical effects as the light-emitting device described in the previous embodiment, the technical effects of the display panel will not be repeatedly described here for the purpose of brevity.

[0144] FIG14 is a schematic diagram of the structure of a display device provided in an embodiment of the present application. Referring to FIG14 , 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.

[0145] Optionally, the light-emitting device 10 included in the display panel 01 can be an organic light-emitting diode (OLED), and the display device can be an OLED display device. The display device can be any appropriate display device, including but not limited to mobile phones, tablet computers, televisions, monitors, laptops, digital photo frames, navigators, e-books, and any other products or components with display functions.

[0146] Since the display device can have substantially the same technical effects as the light-emitting device described in the previous embodiment, the technical effects of the display device will not be repeatedly described here for the purpose of brevity.

[0147] The terms used in the embodiments of this application are only used to explain the embodiments of this application and are not intended to limit this application. Unless otherwise defined, the technical terms or scientific terms used in the embodiments of this application should have the common meaning understood by people with ordinary skills in the field to which this application belongs.

[0148] The terms used in the embodiments of this application are intended solely to illustrate the embodiments of this application and are not intended to limit this application. Unless otherwise defined, technical or scientific terms used in the embodiments of this application should have the same ordinary meaning as those understood by persons of ordinary skill in the art to which this application belongs. The terms "first," "second," "third," and similar terms used in this patent specification and claims do not denote any order, quantity, or importance, but are simply used to distinguish between different components. Similarly, terms such as "a" or "an" do not denote a limitation of quantity, but rather denote the presence of at least one. Terms such as "include" or "comprising" and similar terms mean that the elements or objects listed before "include" or "comprising" include the elements or objects listed after "include" or "comprising," and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used solely to indicate relative positions. When the absolute position of the described objects changes, the relative positions may also change accordingly.

[0149] 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. A light-emitting device, characterized in that, The light-emitting device includes: a first electrode, a first electroluminescent unit, a second electrode, a second electroluminescent unit, and a third electrode, which are sequentially stacked on a substrate; wherein, the color of the light emitted by the first electroluminescent unit is different from the color of the light emitted by the second electroluminescent unit; the potential of the first electrode is higher than the potential of the second electrode and higher than the potential of the third electrode, the potential of the second electrode is different from the potential of the third electrode, and the reflectivity of at least one of the second electrode and the third electrode is greater than 10%.

2. The light-emitting device according to claim 1, wherein, The potential of the second electrode is higher than the potential of the third electrode; The first electroluminescent unit includes: a first hole transport layer, a first light-emitting layer, and a first electron transport layer, which are sequentially stacked in a direction away from the substrate; The second electroluminescent unit includes: a second hole transport layer, a second light-emitting layer, and a second electron transport layer, which are sequentially stacked in a direction away from the substrate.

3. The light-emitting device according to claim 2, characterized in that, The work function of the material of the first electrode is greater than the work function of the material of the second electrode and greater than the work function of the material of the third electrode, and the work function of the material of the second electrode is greater than the work function of the material of the third electrode.

4. The light-emitting device according to claim 3, wherein The material of the first electrode is indium tin oxide, the material of the second electrode is aluminum, and the material of the third electrode is a magnesium-silver alloy; The thickness range of the first electrode is 60 nanometers to 80 nanometers; the thickness range of the second electrode is 10 nanometers to 30 nanometers; the thickness range of the third electrode is 80 nanometers to 120 nanometers.

5. The light-emitting device according to claim 2, characterized in that, The light-emitting device further includes: a fourth electrode and a third electroluminescent unit located between the first electroluminescent unit and the second electrode; wherein, the potential of the fourth electrode is lower than the potential of the first electrode and higher than the potential of the second electrode; The third electroluminescent unit includes: a third hole transport layer, a third light-emitting layer, and a third electron transport layer, which are sequentially stacked in a direction away from the substrate.

6. The light-emitting device according to claim 5, characterized in that, The work function of the material of the first electrode is greater than the work function of the material of the fourth electrode, greater than the work function of the material of the second electrode, and greater than the work function of the material of the third electrode; The work function of the material of the fourth electrode is greater than the work function of the material of the second electrode and greater than the work function of the material of the third electrode; The work function of the material of the second electrode is greater than the work function of the material of the third electrode.

7. The light-emitting device according to claim 6, wherein The material of the first electrode is indium tin oxide, the material of the fourth electrode is indium zinc oxide, the material of the second electrode is aluminum, and the material of the third electrode is a magnesium-silver alloy; The thickness range of the first electrode is 60 nanometers to 80 nanometers; the thickness range of the fourth electrode is 10 nanometers to 30 nanometers; the thickness range of the second electrode is 10 nanometers to 30 nanometers; the thickness range of the third electrode is 80 nanometers to 120 nanometers.

8. The light-emitting device according to claim 1, characterized in that, The potential of the third electrode is higher than the potential of the second electrode; The first electroluminescent unit includes: a first hole transport layer, a first light-emitting layer, and a first electron transport layer, which are sequentially stacked in a direction away from the substrate; The second electroluminescent unit includes: a second electron transport layer, a second light-emitting layer, and a second hole transport layer, which are sequentially stacked in a direction away from the substrate.

9. The light-emitting device according to claim 8, characterized in that, The work function of the material of the first electrode is greater than that of the material of the second electrode and greater than that of the material of the third electrode, and the work function of the material of the third electrode is greater than that of the material of the second electrode.

10. The light-emitting device according to claim 9, characterized in that, The material of the first electrode is indium tin oxide, the material of the second electrode is a magnesium-silver alloy, and the material of the third electrode is aluminum; The thickness range of the first electrode is from 60 nanometers to 80 nanometers; the thickness range of the second electrode is from 10 nanometers to 40 nanometers; the thickness range of the third electrode is from 80 nanometers to 120 nanometers.

11. The light-emitting device according to claim 8, wherein The light-emitting device further includes: a fourth electrode and a third electroluminescent unit located between the first electroluminescent unit and the second electrode; wherein, the potential of the fourth electrode is lower than that of the first electrode and higher than that of the second electrode; The third electroluminescent unit includes: a third hole transport layer, a third light-emitting layer, and a third electron transport layer, which are sequentially stacked in a direction away from the substrate.

12. The light-emitting device according to claim 11, characterized in that, The work function of the material of the first electrode is greater than that of the material of the fourth electrode, greater than that of the material of the second electrode, and greater than that of the material of the third electrode; The work function of the material of the fourth electrode is greater than that of the material of the second electrode and greater than that of the material of the third electrode; The work function of the third electrode is greater than that of the material of the second electrode.

13. The light-emitting device according to claim 12, wherein, The material of the first electrode is indium tin oxide, the material of the fourth electrode is indium zinc oxide, the material of the second electrode is a magnesium-silver alloy, and the material of the third electrode is aluminum; The thickness range of the first electrode is from 60 nanometers to 80 nanometers; the thickness range of the fourth electrode is from 10 nanometers to 30 nanometers; the thickness range of the second electrode is from 5 nanometers to 25 nanometers; the thickness range of the third electrode is from 80 nanometers to 120 nanometers.

14. The light-emitting device according to claim 11, wherein, The thickness range of the first light-emitting layer is from 30 nanometers to 50 nanometers; the thickness range of the third light-emitting layer is from 25 nanometers to 40 nanometers.

15. The light-emitting device according to claim 8, wherein The light-emitting device further includes: a third electroluminescent unit and a fourth electrode located on a side of the third electrode away from the substrate; wherein, the potential of the fourth electrode is lower than that of the third electrode; The third electroluminescent unit includes: a third hole transport layer, a third light-emitting layer, and a third electron transport layer, which are sequentially stacked in a direction away from the substrate.

16. The light-emitting device according to claim 15, wherein The work function of the material of the first electrode is greater than that of the material of the second electrode, greater than that of the material of the third electrode, and greater than that of the material of the fourth electrode; The work function of the third electrode is greater than that of the second electrode and greater than that of the fourth electrode.

17. The light-emitting device according to claim 16, wherein, The material of the first electrode is indium tin oxide, the material of the second electrode is a magnesium-silver alloy, the material of the third electrode is indium zinc oxide, and the material of the fourth electrode is aluminum; The thickness range of the first electrode is from 60 nanometers to 80 nanometers; the thickness range of the second electrode is from 10 nanometers to 30 nanometers; the thickness range of the third electrode is from 5 nanometers to 25 nanometers; the thickness range of the fourth electrode is from 80 nanometers to 120 nanometers.

18. The light-emitting device according to any one of claims 1 to 17, characterized in that, The first electroluminescent unit is a red electroluminescent unit, and the second electroluminescent unit is a green electroluminescent unit.

19. A display panel, characterized in that, The display panel includes: a substrate and a plurality of light-emitting devices as described in any one of claims 1 to 18 located on one side of the substrate.

20. A display device, characterized in that, The display device includes: a power supply component and the display panel as described in claim 19; wherein, the power supply component is used to supply power to the display panel.

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