Organic electroluminescent device, display panel and driving method

Abstract

The invention relates to an organic light-emitting device, a display panel and a driving method, and the organic light-emitting device is characterized in that light-emitting materials are respectively arranged on a first light-emitting layer, a second light-emitting layer and a third light-emitting layer, and the first light-emitting layer and the second light-emitting layer are stacked in a first region of a pixel unit; the third light-emitting layer is arranged in a second area which is arranged side by side with the first area, the first function layer is arranged to penetrate through the second light-emitting layer, and the first light-emitting layer or the second light-emitting layer can be controlled to emit light according to the magnitude of voltage acting on the first function layer. The effective pixel density in unit area can be greatly improved, so that the display resolution can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to an organic electroluminescent device, a display panel and a driving method. BACKGROUND

[0002] At present, organic light emitting diodes (OLED) are widely used in the field of display technology. In the organic electroluminescent device of the OLED display panel, red light emitting materials, green light emitting materials and blue light emitting materials are arranged, and through the combination of different intensities or brightnesses of the three colors, color display can be realized. OLEDs need at least three primary color sub-pixels to form an effective pixel for color display, but at present, the three color light emitting materials are arranged in a light emitting layer in the organic electroluminescent device, which results in a low density of organic electroluminescent devices in a unit area and a low display resolution. SUMMARY

[0003] The present application provides an organic electroluminescent device, a display panel and a driving method to solve the technical problem of how to improve the effective pixel density of OLED in a unit area to improve the display resolution.

[0004] In a first aspect, the present application provides an organic electroluminescent device, comprising: a substrate, a cathode layer, a hole blocking layer, a first functional layer, a light emitting layer and an anode layer. The cathode layer is arranged on the substrate, the anode layer is arranged on the cathode layer, and the hole blocking layer and the light emitting layer are arranged in a stack between the cathode layer and the anode layer. The light emitting layer comprises a plurality of pixel units; each pixel unit comprises a first light emitting layer, a second light emitting layer and a third light emitting layer; the first light emitting layer, the second light emitting layer and the third light emitting layer correspond to light emitting materials of different colors respectively; the first light emitting layer and the second light emitting layer are arranged in a stack in a first area of the pixel unit, the third light emitting layer is arranged in a second area of the pixel unit, and the first area and the second area are arranged side by side. The first functional layer is arranged between the first light emitting layer and the cathode layer, the first functional layer penetrates the second light emitting layer, and the hole blocking layer wraps the first functional layer. When the voltage acting on the first functional layer is greater than or equal to the critical voltage of the first functional layer, the first light emitting layer emits light; when the voltage acting on the first functional layer is less than the critical voltage of the first functional layer, the second light emitting layer emits light.

[0005] Optionally, the organic electroluminescent device further comprises a second functional layer; the third light-emitting layer comprises an upper light-emitting layer and a lower light-emitting layer. The second functional layer is arranged between the upper light-emitting layer and the cathode layer, the second functional layer penetrates the lower light-emitting layer, and the hole blocking layer wraps the second functional layer. When the voltage acting on the second functional layer is greater than or equal to the critical voltage of the second functional layer, the upper light-emitting layer emits light; when the voltage acting on the second functional layer is less than the critical voltage of the second functional layer, the lower light-emitting layer emits light.

[0006] Optionally, the organic electroluminescent device further comprises a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer and an electron injection layer. The electron blocking layer is arranged between the anode layer and the first light-emitting layer and the third light-emitting layer close to the anode layer, the hole transport layer is arranged between the anode layer and the electron blocking layer, and the hole injection layer is arranged between the anode layer and the hole transport layer. The electron transport layer is arranged between the cathode layer and the hole blocking layer, and the electron injection layer is arranged between the cathode layer and the electron transport layer.

[0007] Optionally, the first functional layer is composed of a piezoresistor or a Zener thin film diode; and the second functional layer is composed of a piezoresistor or a Zener thin film diode.

[0008] Optionally, the critical voltage of the first functional layer and the critical voltage of the second functional layer are adjusted by the thickness of the piezoresistor, or adjusted by the doping of the piezoresistor, or adjusted by the thin film material of the Zener thin film diode, or adjusted by the thin film doping.

[0009] Optionally, the organic electroluminescent device further comprises a quarter wave plate and a polarizing plate. The polarizing plate is arranged on the outer side of the substrate, and the quarter wave plate is arranged between the substrate and the polarizing plate.

[0010] Optionally, the substrate, the cathode layer and the anode layer are all transparent materials.

[0011] Optionally, the light-emitting layer comprises red light-emitting material, green light-emitting material and blue light-emitting material. The first light-emitting layer is the first kind of the red light-emitting material, the green light-emitting material and the blue light-emitting material. The second light-emitting layer is the second kind of the red light-emitting material, the green light-emitting material and the blue light-emitting material. The third light-emitting layer is a third one of the red light-emitting material, the green light-emitting material and the blue light-emitting material.

[0012] In a second aspect, the present application provides a display panel, comprising the organic electroluminescent device of any one of the first aspect.

[0013] In a third aspect, the present application provides a method for driving an organic electroluminescent device, applied to the display panel of the second aspect, and the method comprises: determining a voltage acting on the first functional layer according to a color to be displayed of the organic electroluminescent device in the display panel; when the voltage acting on the first functional layer is greater than or equal to a threshold voltage of the first functional layer, the first light-emitting layer emits light; when the voltage acting on the first functional layer is less than the threshold voltage of the first functional layer, the second light-emitting layer emits light.

[0014] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art: the organic electroluminescent device provided by the embodiments of the present application comprises: a substrate, a cathode layer, a hole blocking layer, a first functional layer, a light-emitting layer and an anode layer; the cathode layer is arranged on the substrate, the anode layer is arranged on the cathode layer, and the hole blocking layer and the light-emitting layer are arranged in a stack between the cathode layer and the anode layer; wherein the light-emitting layer comprises a plurality of pixel units; each pixel unit comprises a first light-emitting layer, a second light-emitting layer and a third light-emitting layer; the first light-emitting layer, the second light-emitting layer and the third light-emitting layer correspond to light-emitting materials of different colors respectively; the first light-emitting layer and the second light-emitting layer are arranged in a stack in a first area of the pixel unit, the third light-emitting layer is arranged in a second area of the pixel unit, and the first area and the second area are arranged side by side; the first functional layer is arranged between the first light-emitting layer and the cathode layer, the first functional layer penetrates the second light-emitting layer, and the hole blocking layer wraps the first functional layer; when the voltage acting on the first functional layer is greater than or equal to a threshold voltage of the first functional layer, the first light-emitting layer emits light; when the voltage acting on the first functional layer is less than the threshold voltage of the first functional layer, the second light-emitting layer emits light. The organic electroluminescent device sets the light-emitting materials in the first light-emitting layer, the second light-emitting layer and the third light-emitting layer respectively, the first light-emitting layer and the second light-emitting layer are arranged in a stack in the first area of the pixel unit, the third light-emitting layer is arranged in the second area which is arranged side by side with the first area, and the first functional layer penetrates the second light-emitting layer, so that the first light-emitting layer or the second light-emitting layer can be controlled to emit light according to the size of the voltage acting on the first functional layer. Since the first light-emitting layer and the second light-emitting layer are arranged in the same area of the pixel unit, the effective pixel density in a unit area can be greatly improved, thereby the display resolution can be improved. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 This is a schematic diagram of an OLED display principle; Figure 2 This is a schematic diagram of an OLED display panel structure; Figure 3 This is a schematic diagram of the structure of an organic electroluminescent device provided in one embodiment of this application; Figure 4 A circuit schematic diagram of an organic electroluminescent device provided in one embodiment of this application; Figure 5 A schematic diagram of the structure of an organic electroluminescent device provided in another embodiment of this application; Figure 6 A schematic diagram of the structure of a bidirectional light-emitting organic electroluminescent device provided in one embodiment of this application; Figure 7 A schematic diagram of green light excitation provided in one embodiment of this application; Figure 8 A schematic diagram of red light excitation provided in one embodiment of this application; Figure 9 This is a flowchart illustrating a method for driving an organic electroluminescent device according to an embodiment of this application.

[0019] The attached figures are labeled as follows: 1-Organic electroluminescent device; 11-Substrate; 12-Anode layer; 13-Cathode layer; 14-Polarizer; 15-Quarter-wave plate; 16-Encapsulation layer; 21-Red luminescent material; 22-Green luminescent material; 23-Blue luminescent material; 31-First functional layer; 32-Second functional layer. Detailed Implementation

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0021] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplicity, the elements and settings of the specific examples in the following description are described. Of course, they are only examples and are not intended to limit the present application. In addition, reference numbers and / or letters can be repeated in different examples in the present application. Such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed.

[0022] For the convenience of understanding the technical solutions of the present application, first, the existing OLED display principle and display structure are described. The OLED display principle is shown in Figure 1 , and the OLED structure schematic diagram is shown in Figure 2 . Among them, Cathode represents the cathode, Anode represents the anode, the OLED display panel can include a plurality of organic electroluminescent devices 1, and in each organic electroluminescent device 1, a substrate 11, a cathode layer 13, an electron injection layer (EIL), an electron transport layer (ETL), a hole blocking layer (HBL), a light emitting layer (EML), an electron blocking layer (EBL), a hole transport layer (HTL), a hole injection layer (HIL), an anode layer 12, an encapsulation layer 16, a quarter wave plate 15 and a polarizer 14 are stacked in sequence. Among them, the three light emitting materials (red light emitting material 21, green light emitting material 22 and blue light emitting material 23) in the light emitting layer EML are all arranged in the same light emitting layer, resulting in a low pixel structure density per unit area and a low display resolution.

[0023] To solve the technical problem of how to improve the effective pixel density in the unit area of an OLED to improve the display resolution in the prior art, the present application provides an organic electroluminescent device, a display panel and a driving method, wherein the light-emitting materials are arranged in the first light-emitting layer, the second light-emitting layer and the third light-emitting layer respectively, the first light-emitting layer and the second light-emitting layer are arranged in layers in the first region of the pixel unit, the third light-emitting layer is arranged in the second region which is arranged side by side with the first region, and the first functional layer is arranged to penetrate the second light-emitting layer, so that the first light-emitting layer or the second light-emitting layer can be controlled to emit light according to the size of the voltage acting on the first functional layer. Since the first light-emitting layer and the second light-emitting layer are arranged in the same region of the pixel unit, the effective pixel density in the unit area can be greatly improved, so that the display resolution can be improved.

[0024] Embodiment 1 The first embodiment of the present application provides an organic electroluminescent device, which comprises: Figure 3 a substrate 11, a cathode layer 13, a hole blocking layer HBL, a first functional layer 31, a light-emitting layer EML and an anode layer 12.

[0025] The cathode layer 13 is arranged on the substrate 11, the anode layer 12 is arranged on the cathode layer 13, and the hole blocking layer and the light-emitting layer are arranged in layers between the cathode layer 13 and the anode layer 12.

[0026] The light-emitting layer EML comprises a plurality of pixel units, each pixel unit comprising a first light-emitting layer EML-1, a second light-emitting layer EML-2 and a third light-emitting layer EML-3. The first light-emitting layer EML-1, the second light-emitting layer EML-2 and the third light-emitting layer EML-3 respectively correspond to light-emitting materials of different colors; the first light-emitting layer EML-1 and the second light-emitting layer EML-2 are arranged in layers in the first region of the pixel unit, and the third light-emitting layer EML-3 is arranged in the second region of the pixel unit, the first region being arranged side by side with the second region. That is, in each pixel unit, the first light-emitting layer EML-1 and the second light-emitting layer EML-2 are arranged in layers in the first region, and the third light-emitting layer EML-3 is arranged in the second region which is arranged side by side with EML-1 and EML-2. The first functional layer 31 is arranged between the first light-emitting layer EML-1 and the cathode layer 13, the first functional layer 31 penetrates the second light-emitting layer EML-2, and the hole blocking layer wraps the first functional layer 31.

[0027] When the voltage acting on the first functional layer 31 is greater than or equal to the critical voltage of the first functional layer 31, the first light-emitting layer EML-1 emits light; when the voltage acting on the first functional layer 31 is less than the critical voltage of the first functional layer 31, the second light-emitting layer EML-2 emits light.

[0028] The organic electroluminescent device sets the light-emitting materials in the first light-emitting layer, the second light-emitting layer and the third light-emitting layer respectively, the first light-emitting layer and the second light-emitting layer are arranged in layers in the first region of the pixel unit, the third light-emitting layer is arranged in the second region which is parallel to the first region, and the first functional layer is arranged through the second light-emitting layer, so that the first light-emitting layer or the second light-emitting layer can be controlled to emit light according to the size of the voltage applied to the first functional layer. Since the first light-emitting layer and the second light-emitting layer are arranged in the same region of the pixel unit, the effective pixel density in the unit area can be greatly improved, so that the display resolution can be improved.

[0029] In this embodiment, the circuit schematic diagram of the organic electroluminescent device is as shown in Figure 4 When the voltage applied to the functional layer is less than the critical voltage, the impedance of the functional layer is very high, and the second light-emitting layer EML-2 emits light. When the voltage applied to the functional layer is greater than or equal to the critical voltage, the impedance of the functional layer drops sharply, the second light-emitting layer EML-2 is short-circuited, and the first light-emitting layer emits light.

[0030] Specifically, the first functional layer 31 can be a piezoresistor or a Zener thin film diode. At this time, the critical voltage of the first functional layer 31 can be the wake-up voltage of the piezoresistor or the breakdown voltage of the Zener thin film diode.

[0031] In one embodiment, the light-emitting layer includes red light-emitting material, green light-emitting material and blue light-emitting material. The first light-emitting layer EML-1 is the first of the red light-emitting material, the green light-emitting material and the blue light-emitting material; the second light-emitting layer EML-2 is the second of the red light-emitting material, the green light-emitting material and the blue light-emitting material; and the third light-emitting layer EML-3 is the third of the red light-emitting material, the green light-emitting material and the blue light-emitting material.

[0032] In this embodiment, the first light-emitting layer EML-1 is taken as red light-emitting material, the second light-emitting layer EML-2 is taken as green light-emitting material, and the third light-emitting layer EML-3 is taken as blue light-emitting material. The voltage applied to the first functional layer 31 can be referred to as V division voltage, and the critical voltage of the first functional layer 31 can be referred to as V critical. When V division voltage < V critical, the impedance of the first functional layer is very high, and in the red-green superposition pixel, the hole reaches EML-2 first and then recombines with the electron, and the second light-emitting layer EML-2 emits green light. When V division voltage ≥ V critical, the impedance of the first functional layer drops sharply, the EML-2 light-emitting layer is short-circuited, the hole and the electron recombine in the EML-1, and the first light-emitting layer EML-1 emits red light.

[0033] In the embodiment, the short circuit of the different light-emitting layers is switched by the open circuit or short circuit of the first functional layer under different voltages, and the short circuit of the different light-emitting layers is switched by the hole blocking layer wrapping the first functional layer, so that the stacked display is realized, and the effective pixel density per unit area is improved. For example, the red and green light-emitting layers are vertically stacked in different layers, and the blue light sub-pixel is arranged in the double layers. By the red and green overlapping design, the area of one pixel is reduced by 1 / 3, the pixel density is increased by about 50%, and the double-layer thickness of the blue light sub-pixel is arranged to improve the service life of the blue light pixel.

[0034] In one embodiment, a schematic structural diagram of the organic electroluminescent device is as shown in FIG. 1. Figure 5 The organic electroluminescent device further comprises a second functional layer 32, and the third light-emitting layer EML-3 comprises an upper light-emitting layer EML-31 and a lower light-emitting layer EML-32.

[0035] The second functional layer 32 is arranged between the upper light-emitting layer EML-31 and the cathode layer 13, the second functional layer 32 penetrates the lower light-emitting layer EML-32, and the hole blocking layer HBL wraps the second functional layer 32. When the voltage acting on the second functional layer 32 is greater than or equal to the critical voltage of the second functional layer 32, the upper light-emitting layer EML-31 emits light; when the voltage acting on the second functional layer 32 is less than the critical voltage of the second functional layer 32, the lower light-emitting layer EML-32 emits light.

[0036] In the embodiment, the third light-emitting layer EML-3 also comprises a second functional layer 32, and the light-emitting materials of the upper light-emitting layer EML-31 and the lower light-emitting layer EML-32 of the third light-emitting layer EML-3 are the same. Taking the third light-emitting layer EML-3 as a blue light-emitting material as an example, when blue light is needed, the upper light-emitting layer EML-31 and the lower light-emitting layer EML-32 of the third light-emitting layer EML-3 do not emit light at the same time, but the upper light-emitting layer EML-31 emits light or the lower light-emitting layer EML-32 emits light according to the voltage acting on the second functional layer, so that the service life of the blue pixel can be further improved. For example, when the voltage acting on the second functional layer is greater than or equal to the critical voltage of the second functional layer, the upper light-emitting layer EML-31 emits light, and when the voltage acting on the second functional layer is less than the critical voltage of the second functional layer, the lower light-emitting layer EML-32 emits light.

[0037] Specifically, the second functional layer 32 is composed of a piezoresistor or a Zener diode. The critical voltage of the second functional layer 32 can be the wake-up voltage of the piezoresistor or the breakdown voltage of the Zener diode.

[0038] In one embodiment, the organic electroluminescent device further comprises a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0039] The electron blocking layer is arranged between the anode layer 12 and the first light-emitting layer EML-1 and the third light-emitting layer EML-3 close to the anode layer 12, the hole transport layer is arranged between the anode layer 12 and the electron blocking layer, and the hole injection layer is arranged between the anode layer 12 and the hole transport layer; the electron transport layer is arranged between the cathode layer 13 and the hole blocking layer, and the electron injection layer is arranged between the cathode layer 13 and the electron transport layer.

[0040] Specifically, the organic electroluminescent device further comprises a quarter-wave plate 15 and a polarizer 14.

[0041] The polarizer 14 is arranged on the outer side of the substrate 11, and the quarter-wave plate 15 is arranged between the substrate 11 and the polarizer 14. The quarter-wave plate 15 and the polarizer 14 are arranged on the light-emitting side, and it should be understood that when double-sided light emission is required, the quarter-wave plate 15 and the polarizer 14 should be arranged on both the upper and lower sides of the organic electroluminescent device.

[0042] In one embodiment, the critical voltage of the first functional layer 31 and the critical voltage of the second functional layer 32 are adjusted by the thickness of the pressure-sensitive resistor or by the doping of the pressure-sensitive resistor, or by the thin film material of the Zener thin film diode or by the thin film doping.

[0043] In this embodiment, when the functional layer is selected as a zinc oxide (ZnO) pressure-sensitive resistor, the critical voltage V can be adjusted by adjusting the thickness and doping of the ZnO pressure-sensitive resistor, and when the functional layer is selected as a Zener thin film diode, the critical voltage V can be adjusted by adjusting the thin film material or the thin film doping of the Zener thin film diode.

[0044] In one embodiment, a schematic structural diagram of a bidirectional light-emitting organic electroluminescent device is as shown in Figure 6 The substrate 11, the cathode layer 13 and the anode layer 12 are all transparent materials.

[0045] Taking the first light-emitting layer EML-1 as a red light-emitting material, the second light-emitting layer EML-2 as a green light-emitting material, and the third light-emitting layer EML-3 as a blue light-emitting material as an example. When V is less than V, the impedance of the first functional layer is very high, and in the red-green superimposed pixel, the hole reaches EML-2 first and recombines with the subsequent electron, and the second light-emitting layer EML-2 emits green light. Since the substrate, the cathode layer and the anode layer are all transparent materials, the organic electroluminescent device emits green light on both the upper and lower sides. When V is greater than or equal to V, the impedance of the first functional layer drops sharply, the EML-2 light-emitting layer is short-circuited, the hole and the electron recombine in the EML-1, and the first light-emitting layer EML-1 emits red light. Since the substrate, the cathode layer and the anode layer are all transparent materials, the organic electroluminescent device emits red light on both the upper and lower sides. Similarly, when the third light-emitting layer EML-3 emits blue light, the organic electroluminescent device emits blue light on both the upper and lower sides.

[0046] In one specific embodiment, the first light-emitting layer EML-1 is a red light-emitting material, the second light-emitting layer EML-2 is a green light-emitting material, and the third light-emitting layer EML-3 is a blue light-emitting material. For example, a green light excitation schematic diagram is as shown in Figure 7 The starting voltage of the first functional layer is referred to as Vstart. Considering that the moving speed of holes is faster than that of electrons, when light of a corresponding color is required to be emitted, in order to ensure that holes can first reach the corresponding light-emitting layer to wait for electrons, the thicknesses of the hole injection layer, the hole transport layer, the electron blocking layer, the electron transport layer, and the electron injection layer can also be adjusted to adjust the required time length for electrons and holes to reach the corresponding light-emitting layer. If the required time length for holes to reach the corresponding light-emitting layer is recorded as a first transmission time length, the required time length for electrons to reach the corresponding light-emitting layer is recorded as a second transmission time length, the distance that holes need to pass through is recorded as T hole, and the distance that electrons need to pass through is recorded as T e, the first transmission time length can be adjusted by adjusting the thicknesses of the hole injection layer, the hole transport layer, and the electron blocking layer (T hole), and the second transmission time length can be adjusted by adjusting the thicknesses of the electron injection layer and the electron transport layer (T e). In this embodiment, when Vstart

[0047] A red light excitation schematic diagram is as shown in Figure 8 When Vdrop > Vcritical > Vstart, the resistance of the first functional layer is suddenly reduced, EML-2 is short-circuited, holes and electrons recombine in the first light-emitting layer EML-1, and the first light-emitting layer EML-1 emits red light.

[0048] In the above embodiments of the present application, the anode layer 12 can be selected from transparent films such as indium tin oxide (ITO). The cathode layer 13 can be selected from silver films, aluminum films, or silver-magnesium alloy films (if bidirectional light-emitting transparency is required, the thickness can be set to 2-18 nm). The hole injection layer HIL can be selected from hexaazatriphenylenehexacarbonitrile (HAT-CN) and molybdenum trioxide (MoO3). The hole transport layer HTL can be selected from naphthyl diphenylamine (NPB), tris(carbazylphenyl)triphenylamine (TCTA), tris(9H-fluoren-9-yl-phenylphenylamine)triphenylamine (TAPC), etc. The electron blocking layer EBL can be selected from tris(carbazylphenyl)triphenylamine (TCTA), etc. The light-emitting layer EML can be selected from phosphorescent, fluorescent, thermally activated delayed fluorescent, etc. materials, and different color light emission can be achieved by doping different quantum dots. The hole blocking layer HBL can be selected from N,N'-di(3-methylphenyl)-N,N'-diphenylbenzidine (TmPyPB), etc. The electron transport layer ETL can be selected from tris(8-hydroxyquinolinolato)aluminum (Alq3), 47diphenyl 1,10-phenanthroline (Bphen), 2,2',2''-(1,3,5-benzenetriyl)-tris(phenylbenzimidazole) (TPBi), N,N'-di(3-methylphenyl)-N,N'-diphenylbenzidine (TmPyPB), N,N'-bis(4-tert-butylphenyl)-N,N'-diphenylbenzidine (TpPyPB), etc. The electron injection layer EIL can be selected from lithium 8-hydroxyquinolate (Liq), lithium fluoride (LiF), cesium carbonate (CsCO3), etc. The thickness of the anode layer 12 and the cathode layer 13 can be set to 50-300 nm, and the thickness of the remaining layers can be set to 2-100 nm, without specific limitation.

[0049] Embodiment 2 Based on the same technical concept, the second embodiment of the present application provides a display panel, which comprises a plurality of the organic electroluminescent devices in the first embodiment.

[0050] Since the organic electroluminescent device in the display panel has the light-emitting materials arranged in the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer, the first light-emitting layer and the second light-emitting layer are arranged in a stacked manner in the first region of the pixel unit, the third light-emitting layer is arranged in the second region which is parallel to the first region, and the first functional layer is arranged to penetrate the second light-emitting layer, so that the first light-emitting layer or the second light-emitting layer can be controlled to emit light according to the size of the voltage acting on the first functional layer. Since the first light-emitting layer and the second light-emitting layer are arranged in the same region of the pixel unit, the effective pixel density in the unit area of the display panel can be greatly improved, thereby improving the display resolution of the display panel.

[0051] Embodiment 3 Based on the same technical concept, the third embodiment of the present application provides an organic electroluminescent device driving method, which is applied to the display panel in the second embodiment.Figure 9 The method comprises: Step 901, determining the voltage acting on the first functional layer according to the color to be displayed of the organic electroluminescent device in the display panel; Step 902, the first light-emitting layer emits light when the voltage acting on the first functional layer is greater than or equal to the critical voltage of the first functional layer; Step 903, the second light-emitting layer emits light when the voltage acting on the first functional layer is less than the critical voltage of the first functional layer.

[0052] In the method, the organic electroluminescent device sets the light-emitting material in the first light-emitting layer, the second light-emitting layer and the third light-emitting layer respectively, the first light-emitting layer and the second light-emitting layer are stacked in the first region of the pixel unit, the third light-emitting layer is arranged in the second region which is parallel to the first region, and the first functional layer penetrates the second light-emitting layer. The first light-emitting layer or the second light-emitting layer can be controlled to emit light according to the size of the voltage acting on the first functional layer. Since the first light-emitting layer and the second light-emitting layer are arranged in the same region of the pixel unit, the effective pixel density in the unit area can be greatly improved, thereby improving the display resolution.

[0053] The device embodiments described above are only schematic, wherein the units illustrated as separate components can or can not be physically separate, and the components illustrated as units can or can not be physical units, i.e., can be located in one place or can be distributed on a plurality of network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0054] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be realized by means of software plus a general hardware platform, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0055] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order

[0056] It should be understood that the specific examples described herein are merely illustrative of the present application and are not intended to limit the scope of the present application. In the description, the suffixes "module", "part" or "unit" used for components are merely intended for facilitating description of the present application, and are not intended to limit the present application. Therefore, "module", "part" or "unit" can be mixedly used.

[0057] The above descriptions are merely specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the generic principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Accordingly, the present application will not be limited to the embodiments shown herein but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes: a substrate, a cathode layer, a hole blocking layer, a first functional layer, a light-emitting layer, and an anode layer; The cathode layer is disposed on the substrate, the anode layer is disposed on the cathode layer, and the hole blocking layer and the light-emitting layer are stacked between the cathode layer and the anode layer; The light-emitting layer includes multiple pixel units; each pixel unit includes a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer; the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer correspond to light-emitting materials of different colors; the first light-emitting layer and the second light-emitting layer are stacked sequentially in a first region of the pixel unit, and the third light-emitting layer is disposed in a second region of the pixel unit, with the first region and the second region arranged side by side; The first functional layer is disposed between the first light-emitting layer and the cathode layer, the first functional layer penetrates the second light-emitting layer, and the hole blocking layer encloses the first functional layer; The first light-emitting layer emits light when the voltage applied to the first functional layer is greater than or equal to the critical voltage of the first functional layer; the second light-emitting layer emits light when the voltage applied to the first functional layer is less than the critical voltage of the first functional layer.

2. The organic electroluminescent device according to claim 1, characterized in that, The organic electroluminescent device further includes a second functional layer; the third light-emitting layer includes an upper light-emitting layer and a lower light-emitting layer. The second functional layer is disposed between the upper light-emitting layer and the cathode layer, the second functional layer penetrates the lower light-emitting layer, and the hole blocking layer encloses the second functional layer; The upper light-emitting layer emits light when the voltage applied to the second functional layer is greater than or equal to the critical voltage of the second functional layer; the lower light-emitting layer emits light when the voltage applied to the second functional layer is less than the critical voltage of the second functional layer.

3. The organic electroluminescent device according to claim 1, characterized in that, The organic electroluminescent device further includes: a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, and an electron injection layer; Wherein, the electron blocking layer is disposed between the anode layer and the first light-emitting layer and the third light-emitting layer near the anode layer, the hole transport layer is disposed between the anode layer and the electron blocking layer, and the hole injection layer is disposed between the anode layer and the hole transport layer; The electron transport layer is disposed between the cathode layer and the hole blocking layer, and the electron injection layer is disposed between the cathode layer and the electron transport layer.

4. The organic electroluminescent device according to claim 2, characterized in that, The first functional layer is composed of a varistor or a Zener thin-film diode; the second functional layer is composed of a varistor or a Zener thin-film diode.

5. The organic electroluminescent device according to claim 4, characterized in that, The critical voltage of the first functional layer and the critical voltage of the second functional layer are adjusted by the thickness of the varistor, the doping of the varistor, the thin film material of the Zener thin film diode, or the thin film doping.

6. The organic electroluminescent device according to claim 3, characterized in that, The organic electroluminescent device further includes: a quarter-wave plate and a polarizer; The polarizer is disposed on the outer side of the substrate, and the quarter-wave plate is disposed between the substrate and the polarizer.

7. The organic electroluminescent device according to claim 6, characterized in that, The substrate, the cathode layer, and the anode layer are all made of transparent material.

8. The organic electroluminescent device according to claim 1, characterized in that, The light-emitting layer includes red light-emitting materials, green light-emitting materials, and blue light-emitting materials; The first light-emitting layer is the first of the red light-emitting material, the green light-emitting material, and the blue light-emitting material; The second light-emitting layer is the second of the red light-emitting material, the green light-emitting material, and the blue light-emitting material; The third luminescent layer is the third of the red luminescent material, the green luminescent material, and the blue luminescent material.

9. A display panel, characterized in that, The display panel includes an organic electroluminescent device as described in any one of claims 1-8.

10. A driving method for an organic electroluminescent device, characterized in that, Applied to the display panel of claim 9, the method includes: The voltage applied to the first functional layer is determined based on the color to be displayed by the organic electroluminescent device in the display panel; When the voltage applied to the first functional layer is greater than or equal to the critical voltage of the first functional layer, the first light-emitting layer emits light; The second light-emitting layer emits light when the voltage applied to the first functional layer is less than the critical voltage of the first functional layer.

Images