WO2024046281A1 - 发光器件及其制作方法和显示面板 - Google Patents

发光器件及其制作方法和显示面板 Download PDF

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Publication number
WO2024046281A1
WO2024046281A1 PCT/CN2023/115302 CN2023115302W WO2024046281A1 WO 2024046281 A1 WO2024046281 A1 WO 2024046281A1 CN 2023115302 W CN2023115302 W CN 2023115302W WO 2024046281 A1 WO2024046281 A1 WO 2024046281A1
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Prior art keywords
layer
light
emitting
sub
electrode
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PCT/CN2023/115302
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English (en)
French (fr)
Inventor
刘杨
王丹
陈磊
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京东方科技集团股份有限公司
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Publication of WO2024046281A1 publication Critical patent/WO2024046281A1/zh

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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays

Definitions

  • the present disclosure relates to the field of display technology, and in particular, to a light-emitting device, a manufacturing method thereof, and a display panel.
  • OLED Organic Light Emitting Diode
  • Tandem OLED tandem organic electroluminescent devices
  • Tandem OLED has the advantage of high brightness.
  • Tandem OLED in the related art has a problem of inconsistent light extraction efficiency of the two light-emitting units.
  • the purpose of some embodiments of the present disclosure is to provide a light-emitting device, a manufacturing method thereof, and a display panel, which can improve the luminous efficiency of the light-emitting device.
  • a light-emitting device includes a first electrode, at least two light-emitting units and a second electrode sequentially stacked along a first direction.
  • the at least two light-emitting units include a first light-emitting unit and a second light-emitting unit, and the second light-emitting unit is located between the first light-emitting unit and the second electrode.
  • At least one of the at least two light-emitting units includes a light-emitting layer and an exciton blocking layer located on a side of the light-emitting layer close to the first electrode.
  • the exciton blocking layer includes a first sub-layer and a second sub-layer stacked on each other in the first direction.
  • the first sub-layer is located between the second sub-layer and the light-emitting layer. Wherein, along the first direction, the thickness of the first sub-layer is less than the thickness of the second sub-layer, and the highest occupied orbital energy level of the first sub-layer is higher than that of the second sub-layer. The highest occupied orbital energy level.
  • the thickness of the second sub-layer is up to 6 times the thickness of the first sub-layer.
  • the absolute value of the difference between the highest occupied orbital energy level of the first sub-layer and the highest occupied orbital energy level of the second sub-layer is less than 1 eV.
  • the hole mobility of the first sub-layer is less than the hole mobility of the second sub-layer.
  • the hole mobility of the second sub-layer is at most that of the first sub-layer. 100 times the hole mobility.
  • the luminescent layer includes a first host material and a luminescent material, and the proportion of the luminescent material in the first host material is 4% to 15%.
  • the first light-emitting unit includes a first light-emitting layer
  • the second light-emitting unit includes a second light-emitting layer
  • both the first light-emitting unit and the second light-emitting unit include the exciton blocking layer
  • the proportion of the luminescent material of the second luminescent layer in the first host material of the second luminescent layer is greater than the proportion of the luminescent material of the first luminescent layer in the first luminescent layer.
  • the proportion of the first body material is greater than the proportion of the luminescent material of the first luminescent layer in the first luminescent layer.
  • the proportion of the luminescent material of the second luminescent layer in the first host material of the second luminescent layer is at most the proportion of the luminescent material of the first luminescent layer in the first host material. 3 times the proportion in the material.
  • the hole mobility of the first sub-layer of the exciton blocking layer of the first light-emitting unit is less than or equal to the hole mobility of the first sub-layer of the exciton blocking layer of the second light-emitting unit. Rate.
  • the hole mobility of the first sub-layer of the exciton blocking layer of the second light-emitting unit is at most a hole mobility of the first sub-layer of the exciton blocking layer of the first light-emitting unit. 100 times the rate.
  • the light-emitting device further includes a charge generation layer located between the first light-emitting unit and the second light-emitting unit.
  • the charge generation layer includes an N-type charge generation sub-layer and a P-type charge generation sub-layer stacked along the first direction, and the P-type charge generation sub-layer is located on the N-type charge generation sub-layer.
  • the side of the sub-layer away from the first electrode, the P-type charge generation sub-layer includes a second body material and a P-type doping material, and the P-type doping material occupies 50% of the second body material. The proportion is 1% to 6%.
  • the first light-emitting unit includes the exciton blocking layer; the first light-emitting unit further includes a hole injection layer, the hole injection layer is located in a second layer of the first light-emitting unit.
  • the sub-layer is close to the side of the first electrode, the hole injection layer includes a third body material and the P-type doping material, and the P-type doping material occupies 50% of the third body material. The proportion is 1% to 6%.
  • the proportion of the P-type doping material in the second body material is greater than the proportion of the P-type doping material in the third body material.
  • the difference between the proportion of the P-type doping material in the second body material and the proportion of the P-type doping material in the third body material is Between 0.8% and 5%.
  • a display panel in yet another aspect, includes a pixel defining layer and a plurality of light emitting devices.
  • the pixel definition layer is provided with a plurality of light-emitting openings.
  • the plurality of light-emitting devices respectively cover the plurality of light-emitting openings, and at least one light-emitting device is the above-mentioned light-emitting device.
  • a method of manufacturing a light-emitting device includes forming a first electrode. At least two light-emitting units are formed on the first electrode. At least one of the light-emitting units includes a light-emitting layer and an exciton blocking layer located on a side of the light-emitting layer close to the first electrode.
  • the exciton blocking layer includes a first sub-layer and a second sub-layer stacked on each other in the first direction.
  • a second electrode is formed on the at least two light-emitting units.
  • forming a light-emitting unit on the first electrode includes using an open mask to evaporate a first exciton blocking material on the first electrode to form a second sub-layer.
  • a second exciton blocking material is evaporated on the second sub-layer to form a first sub-layer, and the first sub-layer and the second sub-layer together constitute the exciton blocking material layer.
  • a high-precision metal mask is used to form a light-emitting layer covering the light-emitting opening, and the light-emitting layer is located on the first sub-layer.
  • Figure 1 is a structural diagram of a light emitting device according to some embodiments.
  • Figure 2 is a perspective view of a display panel according to some embodiments.
  • Figure 3 is a cross-sectional view along line AA' of the display panel according to the embodiment shown in Figure 2;
  • Figures 4 to 8 are structural diagrams of the arrangement of sub-pixels in a display panel according to some embodiments.
  • Figure 9 is a cross-sectional view of a display panel according to some embodiments.
  • Figure 10 is an enlarged view of the F area in Figure 3 in some embodiments.
  • Figure 11 is an enlarged view of the F area in Figure 3 in some embodiments.
  • Figure 12 is a molecular structure diagram of material one in a light-emitting device according to some embodiments.
  • Figure 13 is a molecular structure diagram of material two in a light-emitting device according to some embodiments.
  • Figure 14 is a molecular structure diagram of material three in a light-emitting device according to some embodiments.
  • Figure 15 is a molecular structure diagram of material four in a light-emitting device according to some embodiments.
  • Figure 16 is a molecular general diagram of materials one to four in a light-emitting device according to some embodiments.
  • Figure 17 is a flow chart of a method of manufacturing a light-emitting device according to some embodiments.
  • Figure 18 is a flow chart of a method of manufacturing a light emitting device according to some embodiments.
  • first and second are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as “first” and “second” may explicitly or implicitly include one or more of these features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.
  • At least one of A, B and C has the same meaning as “at least one of A, B or C” and includes the following combinations of A, B and C: A only, B only, C only, A and B The combination of A and C, the combination of B and C, and the combination of A, B and C.
  • a and/or B includes the following three combinations: A only, B only, and a combination of A and B.
  • the term “if” is optionally interpreted to mean “when” or “in response to” or “in response to determining” or “in response to detecting,” depending on the context. Similar Alternatively, depending on the context, the phrase “if it is determined" or “if [the stated condition or event] is detected” is optionally interpreted to mean “when it is determined" or “in response to the determination" or “On detection of [stated condition or event]” or “In response to detection of [stated condition or event]”.
  • parallel includes absolutely parallel and approximately parallel, and the acceptable deviation range of approximately parallel may be, for example, a deviation within 5°;
  • perpendicular includes absolutely vertical and approximately vertical, and the acceptable deviation range of approximately vertical may also be, for example, Deviation within 5°.
  • equal includes absolute equality and approximate equality, wherein the difference between the two that may be equal within the acceptable deviation range of approximately equal is less than or equal to 5% of either one, for example.
  • Example embodiments are described herein with reference to cross-sectional illustrations and/or plan views that are idealized illustrations.
  • the thickness of layers and regions are exaggerated for clarity. Accordingly, variations from the shapes in the drawings due, for example, to manufacturing techniques and/or tolerances are contemplated.
  • example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result from, for example, manufacturing. For example, an etched area shown as a rectangle will typically have curved features. Accordingly, the regions shown in the figures are schematic in nature and their shapes are not intended to illustrate the actual shapes of regions of the device and are not intended to limit the scope of the exemplary embodiments.
  • a Tandem OLED device generally includes a first electrode 110 and a second electrode 140. and at least two light-emitting units (for example, the first light-emitting unit 120 and the second light-emitting unit 130 ).
  • the first light-emitting unit 120 and the second light-emitting unit 130 may be located between the first electrode 110 and the second electrode 140 .
  • the first electrode 110 can be used to provide holes, and the second electrode 140 can be used to provide electrons.
  • the first light-emitting unit 120 includes a first light-emitting layer 122 and a first electron blocking layer 121
  • the second light-emitting unit 130 includes a second light-emitting layer 132 and a second electron blocking layer 131 .
  • Each electron blocking layer blocks electrons so that the electrons stay in the adjacent light-emitting layer as much as possible, thereby improving the luminous efficiency of the light-emitting layer.
  • an electron blocking layer 121 is provided on a side of the first luminescent layer 122 close to the first electrode 110
  • an electron blocking layer 121 is provided on a side of the second luminescent layer 132 close to the first electrode 110 .
  • Electron blocking layer 131 When electrons are transmitted from the second electrode 140 to the first electrode 110 . Because the electron transmission is affected by the transmission barrier, the amount of electrons remaining in the second light-emitting layer 132 is greater than the amount of electrons remaining in the first light-emitting layer 122 .
  • the amount of electrons in the first light-emitting layer 122 is less than the amount of electrons in the second light-emitting layer 132 . It can be seen from this that the amount of excitons formed by the recombination of electrons and holes in the first light-emitting layer 122 is less than the amount of excitons formed by the recombination of electrons and holes in the second light-emitting layer 132 .
  • the exciton recombination region of the first light-emitting layer 122 and the exciton recombination region of the second light-emitting layer 132 are different, so that The luminous efficiency of the first light-emitting layer 122 and the second light-emitting layer 132 are also different, resulting in poor light matching between the two light-emitting units in the light-emitting device, and ultimately leading to low overall luminous efficiency of the light-emitting device.
  • the present disclosure provides a light-emitting device, a manufacturing method thereof, and a display panel.
  • FIG. 2 is a perspective view of the display panel 100 according to some embodiments.
  • FIG. 3 is a cross-sectional view along line AA′ of the display panel 100 according to the embodiment shown in FIG. 2 .
  • the display panel 100 includes a display area AA for displaying images and a non-display area SA that does not display images.
  • the non-display area SA surrounds at least one side (for example, one side; another example, All around, including the upper and lower sides and the left and right sides).
  • the non-display area SA may enclose the display area AA and may be located outside the display area AA in at least one direction.
  • the above-mentioned display panel 100 may have a rectangular shape in plan view, or may have a circular, elliptical, rhombus, trapezoid, square or other shapes according to display requirements.
  • the above display panel 100 can be applied to a display device.
  • the display device may be a tablet computer, a smartphone, a head-mounted display, a car navigation unit, a camera, a central information display (CID) provided in a vehicle, a watch-type electronic device or other wearable device, a personal digital assistant (PDA) , small and medium-sized electronic devices such as portable multimedia players (PMP) and game consoles, as well as electronic devices such as medium and large electronic devices including televisions, exterior billboards, monitors, home appliances containing display screens, personal computers and laptops.
  • PDA personal digital assistant
  • the display panel 100 includes a substrate SUB, a light emitting device layer LDL, a light extraction layer CPL, and an encapsulation layer TFE.
  • the substrate SUB includes a plurality of repeatedly arranged pixel unit areas PU.
  • Each pixel unit area PU may include first, second, and third sub-pixel areas P1, P2, and P3 displaying different colors.
  • the first sub-pixel area P1 is configured to display red light
  • the second sub-pixel area P2 is configured to display green light
  • the third sub-pixel area P3 is configured to display blue light.
  • the pixel unit area PU may also include a non-light-emitting area P4.
  • the non-emitting area P4 may be located between the first sub-pixel area P1 and the second sub-pixel area P2, between the second sub-pixel area P2 and the third sub-pixel area P3, and between the third sub-pixel area P3 and the first sub-pixel area. Between area P1.
  • a pixel unit area PU includes a first sub-pixel area P1, a second sub-pixel area P2 and a third sub-pixel area P3.
  • a first sub-pixel area P1, a second sub-pixel area P2 and a third sub-pixel area P3 may be spaced apart from each other along the second direction Y and repeatedly arranged in the display area AA.
  • one pixel unit area PU may include two sub-pixel areas displaying the same color, and the two sub-pixel areas displaying the same color may be arranged adjacently.
  • a pixel unit area PU includes a red sub-pixel area R, two green sub-pixel areas G and a blue sub-pixel area B.
  • the two green sub-pixel areas G in a pixel unit area PU can be the same. Neighbor settings.
  • one pixel unit area PU includes one first sub-pixel area P1, two second sub-pixel areas P2, and one third sub-pixel area P3.
  • One first sub-pixel area P1, two second sub-pixel areas P2 and one third sub-pixel area P3 may be spaced apart from each other and repeatedly arranged in the display area AA along the second direction Y.
  • the non-light-emitting area P4 may also be located between the two second sub-pixel areas P2.
  • the first sub-pixel area P1 in the second direction (direction parallel to the substrate SUB) Y, the first sub-pixel area P1 has a first width WL1, and the second sub-pixel area P2 has a first width WL1.
  • the second width is WL2, and the third sub-pixel area P3 has a third width WL3.
  • the first width WL1, the second width WL2 and the third width WL3 may be different from each other.
  • the display panel 100 may include a plurality of pixel cells located on a base substrate SUB. road.
  • a first pixel circuit S1, a second pixel circuit S2, and a third pixel circuit S3 may be included.
  • the first pixel circuit S1 is located in the first sub-pixel area P1
  • the second pixel circuit S2 is located in the second sub-pixel area P2
  • the third pixel circuit S3 is located in the third sub-pixel area P3.
  • the thin film transistor of at least one of the first pixel circuit S1, the second pixel circuit S2, and the third pixel circuit S3 may be located in the non-emitting region P4.
  • the structure of the pixel circuit includes a variety of structures, which can be selected and set according to actual needs.
  • the pixel circuit may include: at least two transistors (indicated by T) and at least one capacitor (indicated by C).
  • the pixel circuit S may have a structure such as “2T1C”, “6T1C”, “7T1C”, “6T2C” or “7T2C”.
  • the thin film transistor of at least one of the first pixel circuit S1, the second pixel circuit S2, and the third pixel circuit S3 may be a thin film transistor including polysilicon or a thin film transistor including an oxide semiconductor.
  • the thin film transistor when it is a thin film transistor including an oxide semiconductor, it may have a top-gate thin film transistor structure.
  • the thin film transistor can be connected to signal lines, including but not limited to gate lines, data lines and power lines.
  • the display panel 100 may include an insulating layer INL that may be located on the first pixel circuit S1 , the second pixel circuit S2 and the third pixel circuit S3 .
  • the insulating layer INL may have a planarized surface.
  • the insulating layer INL may be formed of an organic layer.
  • the insulating layer INL may include acrylic resin, epoxy resin, imide resin, ester resin, or the like.
  • the insulating layer INL may have through holes exposing electrodes of the first pixel circuit S1, the second pixel circuit S2, and the third pixel circuit S3 to achieve electrical connection.
  • the display panel 100 may include a light emitting device layer LDL and a pixel defining layer PDL located on the base substrate SUB.
  • the pixel defining layer PDL may be formed on the insulating layer INL and defines a plurality of light emitting openings.
  • the pixel definition layer PDL includes a first light-emitting opening K1 located in the first sub-pixel area P1, a second light-emitting opening K2 located in the second sub-pixel area P2, and a third light-emitting opening K3 located in the third sub-pixel area P3.
  • the light-emitting device layer LDL is formed with a plurality of light-emitting devices connected to the pixel circuit S, and the plurality of light-emitting devices respectively cover a plurality of light-emitting openings.
  • the light-emitting devices include a first light-emitting device LD1, a second light-emitting device LD2 and a third light-emitting device LD3.
  • the first light emitting device LD1 covers the first light emitting opening K1
  • the second light emitting device LD2 may cover the second light emitting opening K2
  • the third light emitting device LD3 may cover the third light emitting opening K3.
  • the plurality of light-emitting openings includes at least one light-emitting opening unit KU.
  • One light-emitting opening unit KU includes a first light-emitting opening K1, a second light-emitting opening K2, and a third light-emitting opening K3 corresponding to different colors.
  • One light-emitting opening unit KU corresponds to one pixel unit area PU, and the number of light-emitting openings in the light-emitting opening unit KU is equal to the number of sub-pixel areas in the pixel unit area. Multiple light-emitting openings in one light-emitting opening unit KU correspond to multiple sub-pixel areas in one pixel unit area PU.
  • one light-emitting opening unit KU may include one or more first light-emitting openings K1, one or more second light-emitting openings K2, and one or more third light-emitting openings K3.
  • the first light emitting device LD1 may cover the first light emitting opening K1
  • the second light emitting device LD2 may cover the second light emitting opening K2
  • the third light emitting device LD3 may cover the third light emitting opening K3.
  • the light-emitting device may include a first electrode, at least two light-emitting units 200 and a second electrode sequentially stacked along the first direction (ie, the direction perpendicular to the substrate SUB) X.
  • display panel 100 is a top-emitting display panel 100 .
  • the first electrode is a reflective electrode that can reflect light, such as an anode;
  • the second electrode is a transmissive electrode that can transmit light, such as a cathode. In this way, a microcavity structure is formed between the anode and cathode.
  • display panel 100 is a bottom-emitting display panel 100 .
  • the first electrode is a transmissive electrode that can transmit light, such as an anode;
  • the second electrode CE is a reflective electrode that can reflect light, such as a cathode. In this way, a microcavity structure is formed between the anode and cathode.
  • the first electrode includes a first electrode AE1 located in the first sub-pixel area P1, a first electrode AE2 located in the second sub-pixel area P2, and a first electrode located in the third sub-pixel area P3.
  • AE1 located in the first sub-pixel area P1
  • first electrode AE2 located in the second sub-pixel area P2
  • the first electrode may include a high work function material, such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir or Cr metals and mixtures thereof, or may be made of ITO. , IZO or IGZO and other transparent conductive oxide materials.
  • the size of the first electrode in the first direction X may be in the range of 80 nm to 200 nm.
  • the first electrode AE1 may include a laminated composite structure of transparent conductive oxide/metal/transparent conductive oxide.
  • the transparent conductive oxide material is, for example, ITO or IZO
  • the metal material is, for example, Au, Ag, Ni or Pt.
  • the anode structure is: ITO/Ag/ITO.
  • the size of the metal in the first direction X may be in the range of 80 nm to 100 nm; the size of the transparent conductive oxide in the first direction X may be in the range of 5 nm to 10 nm.
  • the average reflectivity of the first electrode for visible light may be in the range of 85% to 95%.
  • display panel 100 is a bottom-emitting display panel 100 .
  • the first electrode may include a transparent conductive oxide such as ITO, IZO or IGZO.
  • the second electrode CE may include metal material or alloy material.
  • the metal material is, for example, Al, Ag or Mg
  • the alloy material is, for example, Mg:Ag alloy or Al:Li alloy.
  • the cathode includes a Mg:Ag alloy, where the ratio between the Mg element and the aluminum element may be in the range of 3:7 ⁇ 1:9.
  • display panel 100 is a top-emitting display panel 100 .
  • the size of the second electrode in the first direction X may be in the range of 10 nm to 20 nm.
  • the transmittance of the second electrode CE for light with a wavelength of 530 nm may be greater than or equal to 50%, such as 50%, 55%, 60%, 65%, etc.
  • display panel 100 is a bottom-emitting display panel 100 .
  • the size of the second electrode CE in the first direction may be greater than or equal to 80 nm, such as 80 nm, 85 nm, 90 nm, 95 nm, etc. In this way, it can be ensured that the second electrode CE serves as a reflective electrode and has a good reflectivity for light.
  • the second electrode includes a second electrode CE1 located in the first sub-pixel area P1, a second electrode CE2 located in the second sub-pixel area P2, and a second electrode located in the third sub-pixel area P3.
  • CE1 located in the first sub-pixel area P1
  • CE2 located in the second sub-pixel area P2
  • CE3 located in the third sub-pixel area P3.
  • At least two light emitting units 200 between the first electrode and the second electrode may be stacked in the first direction X.
  • the number of light-emitting units 200 between the first electrode and the second electrode CE may be two, three, or other numbers, which are not limited here.
  • a first light-emitting unit 210 and a second light-emitting unit 220 are included between the first electrode AE and the second electrode CE, that is, two light-emitting units 210 and 220 are included between the first electrode AE and the second electrode CE.
  • Light emitting unit 200 The first light-emitting unit 210 may be in direct contact with the first electrode AE, the second light-emitting unit 220 may be located between the first light-emitting unit 210 and the second electrode CE, and the second light-emitting unit 220 may be in direct contact with the second electrode CE.
  • the first light emitting unit 210 includes a first light emitting layer EML1, a first transmission layer TL1 and a second transmission layer TL2.
  • the first transmission layer TL1 is located between the first light-emitting layer EML1 and the first electrode AE. It can be understood that the size of the first transmission layer TL1 in the first direction separation distance in the direction.
  • the first transport layer TL1 is configured to transport holes from the first electrode AE to the first light emitting layer EML1.
  • the second transmission layer TL2 is located between the first light-emitting layer EML1 and the second light-emitting unit 220. It can be understood that the size of the second transmission layer TL2 in the first direction The separation distance in the first direction X.
  • the second transport layer TL2 is configured to transport electrons to the first light emitting layer EML1. In this way, holes and electrons recombine in the first light-emitting layer EML1, causing the first light-emitting layer EML1 to emit light.
  • the second light emitting unit 220 includes a second light emitting layer EML2, a third transmission layer TL3 and a fourth transmission layer TL4.
  • the third transmission layer TL3 is located between the second light-emitting layer EML2 and the first light-emitting unit 210. It can be understood that the size of the third transmission layer TL3 in the first direction X is equal to the distance between the first light-emitting unit 210 and the second light-emitting layer EML2. The separation distance in the first direction X.
  • the third transport layer TL3 is configured to transport holes to the second light emitting layer EML2.
  • the fourth transmission layer TL4 is located between the second light-emitting layer EML2 and the Between the two electrodes CE, it can be understood that the size of the fourth transmission layer TL4 in the first direction X is equal to the separation distance in the first direction X between the second light-emitting layer EML2 and the second electrode CE.
  • the fourth transport layer TL4 is configured to transport electrons from the second electrode CE to the second light emitting layer EML2. In this way, holes and electrons recombine in the second light-emitting layer EML2, causing the second light-emitting layer EML2 to emit light.
  • the light-emitting device further includes a charge generation layer 300 located between two adjacent light-emitting units 200 .
  • the charge generation layer 300 includes an N-type charge generation sub-layer 320 and a P-type charge generation sub-layer 310 stacked along a first direction, and the P-type charge generation sub-layer 310 is located away from the N-type charge generation sub-layer 320. side of electrode AE.
  • the N-type charge generation sub-layer 320 may directly contact the first light-emitting unit 210.
  • the N-type charge generation sub-layer 320 directly contacts the second transport layer TL2 to provide electrons to the first light-emitting unit 210.
  • the P-type charge generation sub-layer 310 may directly contact the second light-emitting unit 220.
  • the P-type charge generation sub-layer 320 directly contacts the third transport layer TL3 to provide holes to the second light-emitting unit 220.
  • the above-mentioned second transport layer TL2 is configured to transport the electrons provided by the charge generation layer 300 to the first light emitting layer EML1, so that the holes provided by the first electrode AE and the electrons provided by the charge generation layer 300 are in the first The luminescent layer EML1 emits composite light.
  • the above-mentioned third transport layer TL3 is configured to transport holes provided by the charge generation layer 300 to the second light-emitting layer EML2, so that the holes provided by the charge generation layer 300 and the electrons provided by the second electrode CE are recombined in the second light-emitting layer EML2 glow.
  • the charge generation layer 300 may include metal, non-doped organic matter, an organic PN junction composed of P-type and N-type doping, or a metal oxide, etc., which is not limited here.
  • the absolute value of the difference between the wavelength of the light emitted by the first light-emitting layer EML1 and the wavelength of the light emitted by the second light-emitting layer EML2 may be less than or equal to 10 nm.
  • two light-emitting units 200 in the same light-emitting device emit the same or similar light.
  • the concentration of the spectral superposition of the two light-emitting units 200 can be improved, and the color purity and light extraction efficiency of the light can be improved.
  • the light-emitting device is a blue light-emitting device
  • the wavelength of the light emitted by the first light-emitting layer EML1 in the blue light-emitting device is 460 nm
  • the wavelength of the light emitted by the second light-emitting layer EML2 in the blue light-emitting device can be 450 nm to 470 nm. In this way, the light extraction efficiency of the light corresponding to the wavebands with overlapping wavelengths in the light-emitting device can be improved.
  • the difference rate between the wavelength of the light emitted by the first light-emitting layer EML1 at the spectral peak and the wavelength of the light emitted by the second light-emitting layer EML2 at the spectral peak is less than 5%.
  • the two kinds of light emitted by the two light-emitting units 200 in the same light-emitting device are The same or similar wavelength to the peak of the spectrum. In this way, the concentration of the spectral superposition of the two light-emitting units 200 can be improved, and the color purity and light extraction efficiency of the light can be improved.
  • the light-emitting device is a red light-emitting device.
  • the wavelength of the light emitted by the first light-emitting layer EML1 in the red light-emitting device is at the spectrum peak of 530 nm.
  • the wavelength of the light emitted by the second light-emitting layer EML2 in the red light-emitting device is at the spectrum peak of 504nm ⁇ 557nm. In this way, the light extraction efficiency of the light corresponding to the wavebands with overlapping wavelengths in the light-emitting device can be improved.
  • the first transport layer TL1 may include a first hole injection layer HIL1 and a first hole transport layer HTL1 .
  • the first hole injection layer HIL1 is located between the first electrode AE and the first hole transport layer HTL1.
  • the first hole injection layer HIL1 is configured to inject holes from the first electrode AE into the first hole transport layer HTL1 .
  • the first hole transport layer HTL1 is located between the first hole injection layer HIL1 and the first light emitting layer EML1.
  • the first hole transport layer HTL1 is configured to transport holes injected by the first hole injection layer HIL1 to the first hole transport layer HTL1.
  • the light-emitting layer EML1 causes holes to recombine with electrons in the first light-emitting layer EML1, thereby realizing the light emission of the first light-emitting layer EML1.
  • the first hole injection layer HIL1 may include a third body material and a P-type doping material.
  • the third host material may include poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), polythiophene, polyaniline, polypyrrole, copper phthalocyanine, and 4,4',4"- Tris(N,N-phenyl-3-basic blue) triphenylamine (m-MTDATA).
  • the P-type dopant material can be one of the quinone derivatives or axene compounds, but is not limited to this.
  • P-type dopant P-type dopant
  • quinone derivatives such as tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane (F4-TCNQ) ,4,4”,4”-((1E,1”E,1”E)-cyclopropane-1,2,3-tris(cyanomethylylidene))-tris(2,3,5 ,6-tetrafluorobenzonitrile).
  • TCNQ tetracyanoquinodimethane
  • F4-TCNQ 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane
  • F4-TCNQ 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane
  • the proportion of P-type doping material in the third body material is 1% to 6%.
  • the hole injection efficiency of the first hole injection layer HIL1 can be improved by controlling the proportion of the P-type doping material in the third host material, thereby increasing the amount of holes transmitted to the first light-emitting layer EML1.
  • the amount of exciton recombination in the first light-emitting layer EML1 is increased, so as to increase the luminous efficiency of the first light-emitting layer EML1.
  • the P-type charge generation sub-layer 310 includes a second body material and a P-type doping material.
  • the second host material may include metals, non-doped organic matter, and the like. Among them, the proportion of P-type doping material in the second host material is 1% to 6%. For example 1%, 2%, 3%, 4%, 5% or 6%.
  • the difficulty of hole transport in the P-type charge generation sub-layer 310 can be reduced, so that holes can be injected into the film layer (such as the second hole injection layer HIL2) adjacent to the P-type charge generation sub-layer 310, that is,
  • the amount of holes moving through the P-type charge generation sublayer 310 to the second electrode CE the amount of holes in the second light-emitting layer EML2 is increased, thereby increasing the amount of exciton recombination in the second light-emitting layer EML2, This further improves the luminous efficiency of the second luminescent layer EML2.
  • the proportion of the P-type doping material in the second body material is greater than the proportion of the P-type doping material in the third body material.
  • the difference between the proportion of the P-type doping material in the second body material and the proportion of the P-type doping material in the third body material is between 0.8% and 5%.
  • 0.8%, 1%, 2%, 3% or 4% is 0.8%, 1%, 2%, 3% or 4%.
  • the second transport layer TL2 may include a first electron transport layer ETL1 and a first electron injection layer EIL1.
  • the first electron injection layer EIL1 is located between the first electron transport layer ETL1 and the charge generation layer 300 .
  • the first electron injection layer EIL1 is configured to inject electrons provided by the N-type charge generation sublayer 320 into the first electron transport layer ETL1 .
  • the first electron transport layer ETL1 is located between the first electron injection layer EIL1 and the second luminescent layer EML2.
  • the first electron transport layer ETL1 is configured to transport electrons injected by the first electron injection layer EIL1 to the first luminescent layer EML1, such that The electrons recombine with holes in the first light-emitting layer EML1, thereby realizing the light emission of the first light-emitting layer EML1.
  • the third transport layer TL3 may include a second hole injection layer HIL2 and a second hole transport layer HTL2.
  • the second hole injection layer HIL2 is located between the charge generation layer 300 and the second hole transport layer HTL2.
  • the second hole injection layer HIL2 is configured to inject holes of the P-type charge generation sublayer into the second hole transport layer.
  • the second hole transport layer HTL2 is located between the second hole injection layer HIL2 and the second light emitting layer EML2.
  • the second hole transport layer HTL2 is configured to transport holes injected by the second hole injection layer HIL2 to the second hole injection layer HIL2.
  • the light-emitting layer EML2 causes holes to recombine with electrons in the second light-emitting layer EML2, thereby achieving light emission of the second light-emitting layer EML2.
  • the fourth transport layer TL4 may include a second electron transport layer ETL2 and a second electron injection layer EIL2.
  • the second electron injection layer EIL2 is located between the second electron transport layer ETL2 and the second electrode CE, and the second electron injection layer EIL2 is configured to inject electrons provided by the second electrode CE into the second electron transport layer ETL2.
  • the second electron transport layer ETL2 is located between the second electron injection layer EIL2 and the second luminescent layer CE, and the second electron transport layer ETL2 is configured to transport electrons injected by the second electron injection layer EIL2 to the second luminescent layer EML2, such that The electrons recombine with holes in the second light-emitting layer EML2, thereby realizing the light emission of the second light-emitting layer EML2.
  • the fourth transport layer TL4 may further include a hole blocking layer HBL.
  • the hole blocking layer HBL may be located between the second electron transport layer ETL2 and the second light emitting layer EML2, and the hole blocking layer HBL is configured to block holes in the second light emitting layer EML2 from moving toward the second electrode CE.
  • At least one of the at least two light-emitting units further includes an exciton blocking layer.
  • any one of the two light-emitting units 200 may include an exciton blocking layer BL (BL1/BL2).
  • the first light-emitting unit 210 may include an exciton blocking layer BL (BL1/BL2).
  • An exciton blocking layer BL1 (eg Figure 10).
  • the first light-emitting unit 210 includes a first exciton blocking layer BL1
  • the second light-emitting unit 220 includes a second exciton blocking layer BL2 (eg, FIG. 11).
  • the exciton blocking layer may be located on a side of the light-emitting layer of the light-emitting unit close to the first electrode.
  • the first exciton blocking layer BL1 includes a first sub-layer BL11 and a second sub-layer BL12 stacked on each other in the first direction X.
  • the first sub-layer BL11 may be configured to block electrons
  • the second sub-layer BL12 may be configured to transport holes.
  • first sub-layer BL11 may be located between the second sub-layer BL12 and the first emitting layer EML1
  • second sub-layer BL12 may be located between the first sub-layer BL11 and the first emitting layer EML1.
  • the first sub-layer BL11 of the exciton blocking layer BL1 is located between the first light-emitting layer EML1 and the second sub-layer BL12.
  • the first sub-layer BL11 may be configured to both transport holes and block electrons and excitons.
  • the second sub-layer BL12 may be configured to transport holes.
  • the second light-emitting unit 220 includes an electron blocking layer EBL located between the second light-emitting layer EML2 and the second hole transport layer HTL2.
  • the holes provided by the first electrode AE (for example, the anode) can be transmitted in the direction from the first electrode AE to the second electrode CE.
  • the holes provided by the first electrode AE can first come to the first exciton blocking layer BL1 of the first light-emitting unit 210, and can pass through the second sub-layer BL12 and the second sub-layer BL12 in turn.
  • a sub-layer BL11 is then implanted into the first light-emitting layer EML1.
  • Some holes injected into the first light-emitting layer EML1 may recombine with electrons in the first light-emitting layer EML1 to form excitons, so that the first light-emitting layer EML1 emits light.
  • Some holes in the first light-emitting layer EML1 that have not recombined with electrons can continue to be transported toward the second light-emitting unit 220 . After the holes leave the first light-emitting layer EML1, they can pass through the charge generation layer 300 and the electron blocking layer EBL in sequence, and be injected into the second light-emitting layer EML2 of the second light-emitting unit 220, and can recombine with electrons in the second light-emitting layer EML2. So that the second light-emitting layer EML2 emits light.
  • the transport amount of holes gradually decreases in the direction from the first electrode AE to the second electrode CE. It can be understood that the amount of holes transferred to the first sub-layer BL11 is smaller than the amount of holes transferred to the second sub-layer BL12. Although the transport amount of holes gradually decreases from the first electrode AE to the second electrode CE, the P-type charge generation sublayer 310 can provide some holes and inject holes into the second light-emitting layer. EML2, thereby being able to reduce the amount of holes lost by the second light-emitting layer EML2 due to the transmission barrier to a certain extent.
  • the electrons provided by the second electrode CE can be transmitted from the second electrode CE to the first electrode AE.
  • electrons provided by the second electrode CE may be first injected into the second light-emitting layer EML2 of the second light-emitting unit 220 and recombine with holes in the second light-emitting layer EML2 to form excitons.
  • the electrons in the second light-emitting layer EML2 that have not been recombined with holes can continue to be transported in the direction of the first electrode AE. Subsequently, the electrons can first pass through the electron blocking layer EBL.
  • the electron blocking layer EBL can block the electrons, some electrons can still pass through the electron blocking layer EBL and be transmitted to the first light-emitting unit 210 .
  • the N-type charge generation sublayer 320 can provide some electrons and inject electrons into the first light-emitting unit 210. Therefore, the amount of electrons lost by the first light-emitting unit 210 due to the electron blocking layer EBL and the transmission barrier can be reduced.
  • the first sub-layer BL11 can block the excitons and electrons in the first light-emitting layer EML1, thereby allowing them to move from the first light-emitting layer EML1 to the first electrode AE.
  • the vast majority of electrons stay in the first light-emitting layer EML1.
  • the electron blocking layer in Figure 1 In addition to blocking electrons in the first light-emitting layer EML1, the electron blocking layer in Figure 1 also needs to have the ability to block excitons and transport holes. Therefore, the electron blocking layer's ability to block electrons is poor. There are still more electrons lost in the first light-emitting layer EML1, which results in fewer electrons remaining in the first light-emitting layer EML1. In this way, the number of electrons remaining in the first light-emitting layer EML1 is equal to the number of electrons remaining in the second light-emitting layer EML2. The gap is a bit big.
  • the first sub-layer BL11 can mainly block electrons in the first light-emitting layer EML1, it can reduce the loss of electrons in the first light-emitting layer EML1, thereby increasing the amount of electrons remaining in the first light-emitting layer EML1, thereby increasing the first The amount of excitons recombined in the light-emitting layer EML1.
  • the performance of blocking electrons in the first light-emitting layer EML1 can be improved to reduce the amount of electron loss in the first light-emitting layer EML1.
  • the amount of electrons retained in the first light-emitting layer EML1 is increased, thereby increasing the amount of excitons recombining electrons and holes in the first light-emitting layer EML1.
  • the first sub-layer BL11 can also block excitons in the first light-emitting layer EML1, so that the excitons stay in the first light-emitting layer EML1 as much as possible, thereby further increasing the excitation energy remaining in the first light-emitting layer EML1.
  • the amount of excitons remaining in the first light-emitting layer EML1 and the amount of excitons remaining in the second light-emitting layer EML2 are as close as possible, thereby improving the luminous efficiency of the first light-emitting layer EML1, so that the first light-emitting layer EML1
  • the luminous efficiency is as consistent as possible with the luminous efficiency of the second luminescent layer EML2.
  • the light-emitting device includes two light-emitting units 200 , each of the two light-emitting units 200 includes an exciton blocking layer BL.
  • the first light-emitting unit 210 includes a first exciton blocking layer BL1
  • the second light-emitting unit 220 includes a second exciton blocking layer BL2.
  • the holes provided by the first electrode AE after leaving the first electrode AE, can first come to the first exciton blocking layer BL1, and can pass through the second sub-layer BL12 and the first sub-layer BL11 in sequence, and then be injected into the first sub-layer BL11.
  • Some holes injected into the first light-emitting layer EML1 may recombine with electrons in the first light-emitting layer EML1 to form excitons, so that the first light-emitting layer EML1 emits light.
  • the holes that are not recombined with electrons in the first light-emitting layer EML1 can continue to be transported in the direction of the second electrode CE.
  • the holes leave the first light-emitting layer EML1, they can pass through the charge generation layer 300 and the second exciton blocking layer BL2 in sequence, and then be injected into the second light-emitting layer EML2, so that the second light-emitting layer EML2 emits light.
  • the P-type charge generation sublayer 310 can provide some holes and inject holes into the second light-emitting layer EML2, which can increase the amount of holes lost by the second light-emitting layer EML2 due to the transmission barrier to a certain extent.
  • the electrons provided by the second electrode CE can be injected into the second light-emitting layer EML2 of the second light-emitting unit 220 after leaving the second electrode CE, and recombine with holes in the second light-emitting layer EML2 to form excitons.
  • the electrons in the second light-emitting layer EML2 that have not been recombined with holes can continue to be transported in the direction of the first electrode AE.
  • the electrons can first pass through the first sub-layer BL21 and the second sub-layer BL22 of the second exciton blocking layer BL2, because the first sub-layer BL21 of the second exciton blocking layer BL2 has better ability to block electrons, so Most electrons can be blocked in the second light-emitting layer EML2, and some electrons can continue to transmit toward the first electrode AE through the first sub-layer BL21 and the second sub-layer BL22 of the second exciton blocking layer BL2.
  • the electrons leave the second light-emitting layer EML2, they may pass through the charge generation layer 300 in sequence and then be injected into the first light-emitting layer EML1, so that the first light-emitting layer EML1 emits light.
  • the N-type charge generation sublayer 320 can provide some electrons and inject electrons into the first light-emitting layer EML1, which can increase the amount of electrons lost by the first light-emitting layer EML1 due to the transmission barrier to a certain extent.
  • the first sub-layer BL11 of the first exciton blocking layer BL1 can block the excitons and electrons in the first light-emitting layer EML1, thereby enabling the Most of the electrons in the first light-emitting layer EML1 that move toward the first electrode AE stay in the first light-emitting layer EML1.
  • a first exciton blocking layer BL1 is provided on the side of the first emitting layer EML1 close to the first electrode AE, and a first exciton blocking layer BL1 is provided on the side of the second emitting layer EML2 close to the first electrode AE.
  • a second exciton blocking layer BL2 is provided, and all the above exciton blocking layers have a double film layer structure. It can improve the blocking performance of electrons in each light-emitting unit.
  • the thickness of the first sub-layer of the exciton blocking layer may be less than the thickness of the second sub-layer.
  • the thickness of the first sub-layer BL11 of the first exciton blocking layer BL1 may be smaller than the thickness of the second sub-layer BL12 of the first exciton blocking layer BL1.
  • the thickness of the first sub-layer BL11 may range from 4 nm to 25 nm
  • the thickness of the second sub-layer BL12 may range from 20 nm to 50 nm.
  • the thickness of the second sub-layer BL12 is at most 6 times the thickness of the first sub-layer BL11. That is, the ratio of the thickness of the second sub-layer BL12 to the thickness of the first sub-layer BL11 is in the range of 1 to 6, such as 1, 2, 3, 4, 5, and 6.
  • the highest occupied orbital (HOMO) energy level of the first sublayer is higher than that of the second sublayer.
  • the highest occupied orbital energy level of the sublayer is higher than that of the second sublayer.
  • Holes can easily jump from a film with a lower HOMO energy level to a film with a higher HOMO energy level, but they cannot easily jump from a film with a higher HOMO energy level to a film with a lower HOMO energy level. Therefore, making the HOMO energy level of the first sublayer higher than the HOMO energy level of the second sublayer can reduce the difficulty of holes transitioning from the second sublayer to the first sublayer, thus improving the hole transmission rate. This allows more holes to successfully transition to the first sub-layer, thereby increasing the amount of holes transported to the first sub-layer.
  • the absolute value of the difference between the highest occupied orbital energy level of the first sub-layer and the highest occupied orbital energy level of the second sub-layer is less than 1 eV.
  • the first sub-layer in the same exciton blocking layer (eg BL1 or BL2), also configured to transport holes.
  • the hole mobility of the first sub-layer may be greater than the hole mobility of the second sub-layer.
  • the hole mobility of the first sub-layer may also be equal to the hole mobility of the second sub-layer.
  • the hole mobility of the first sub-layer The mobility may also be smaller than the hole mobility of the second sublayer.
  • the hole mobility of the first sub-layer is less than the hole mobility of the second sub-layer.
  • Such an arrangement can improve the hole mobility on the side of the light-emitting layer close to the first electrode.
  • the hole mobility of the second sub-layer BL12 is at most 100 times that of the first sub-layer BL11. That is, the ratio of the hole mobility of the second sub-layer BL12 to the hole mobility of the first sub-layer BL11 is in the range of 1 to 100, such as 1, 2, 3, 4...98, 99, 100.
  • the ratio between the hole mobility of the first sub-layer BL11 and the hole mobility of the second sub-layer BL12 can be flexibly adjusted according to the actual needs of the light-emitting device, so as to meet the exciton blocking requirements of the light-emitting unit. layer hole mobility requirements.
  • each light-emitting unit 200 of the light-emitting device includes an exciton blocking layer
  • the hole mobility of the exciton blocking layer BL in different light-emitting units 200 may be the same or different, which is not limited here.
  • the hole mobility of the first sub-layer BL11 of the first exciton blocking layer BL1 of the first light-emitting unit 210 may be greater than or less than or equal to the third sub-layer BL11 of the second light-emitting unit 220 .
  • the hole mobility of the first sub-layer BL11 of the first exciton blocking layer BL1 of the first light-emitting unit 210 is less than or equal to the first sub-layer BL11 of the second exciton blocking layer BL2 of the second light-emitting unit 220
  • the hole mobility in this way, can increase the difficulty of hole transmission to the first light-emitting layer EML1 through the first sub-layer BL11 of the first exciton blocking layer BL1, thereby reducing the amount of holes transmitted to the first light-emitting layer EML1, This further reduces the number of excitons in which holes recombine in the first light-emitting layer EML1.
  • the difficulty of hole transmission to the second light-emitting layer EML2 can also be reduced through the first sub-layer BL21 of the second exciton blocking layer BL2, thereby increasing the amount of holes transmitted to the second light-emitting layer EML2, thereby increasing the number of holes in the second light-emitting layer EML2.
  • the hole mobility of the first sub-layer BL21 of the second exciton blocking layer BL2 of the second light-emitting unit 210 is at most the first sub-layer BL11 of the first exciton blocking layer BL1 of the first light-emitting unit 220. 100 times the hole mobility. That is, the ratio of the hole mobility of the first sub-layer BL21 of the second exciton blocking layer BL2 to the hole mobility of the first sub-layer BL11 of the first exciton blocking layer BL1 is In the range of 1 to 100.
  • the hole mobility of the first sub-layer BL21 of the exciton blocking layer BL2 of the second light-emitting unit 220 may be 1.5 ⁇ 10 -4 cm 2 /(V ⁇ s), and the first light-emitting unit 220 may have a hole mobility of 1.5 ⁇ 10 -4 cm 2 /(V ⁇ s).
  • the hole mobility of the first sub-layer BL11 of the exciton blocking layer BL1 of 210 may be 9.9 ⁇ 10 -6 cm 2 /(V ⁇ s).
  • the hole mobility of the second sub-layer BL12 of the first exciton blocking layer BL1 of the first light-emitting unit 210 may be greater than or less than or equal to the third sub-layer BL12 of the second light-emitting unit 220 .
  • the hole mobility of the second sub-layer BL12 of the first exciton blocking layer BL1 of the first light-emitting unit 210 is less than or equal to the second sub-layer of the second exciton blocking layer BL2 of the second light-emitting unit 220
  • the hole mobility of BL22 is high, the difficulty of hole transmission to the first emitting layer EML1 can be increased through the second sub-layer BL12 of the first exciton blocking layer BL1, thereby reducing the amount of holes transmitted to the first emitting layer EML1.
  • the difficulty of hole transmission to the second light-emitting layer EML2 can be reduced through the second sub-layer BL22 of the second exciton blocking layer BL2, thereby increasing the amount of holes transmitted to the second light-emitting layer EML2.
  • the charge generation layer 300 can provide some holes to the second light-emitting layer EML2. In this way, it is convenient to adjust the hole amounts corresponding to the second light-emitting layer EML2 and the first light-emitting layer EML1 so that the hole amounts of the two are as close as possible, thereby improving the luminous efficiency of the light-emitting device.
  • the hole mobility of the second sub-layer BL22 of the second exciton blocking layer BL2 of the second light-emitting unit 210 is at most the second sub-layer BL12 of the first exciton blocking layer BL1 of the first light-emitting unit 220. 100 times the hole mobility. That is, the ratio of the hole mobility of the second sub-layer BL22 of the second exciton blocking layer BL2 to the hole mobility of the second sub-layer BL12 of the first exciton blocking layer BL1 is in the range of 1 to 100.
  • the hole mobility of the second sub-layer BL22 of the exciton blocking layer BL2 of the second light-emitting unit 220 may be 8.2 ⁇ 10 -4 cm 2 /(V ⁇ s), and the first light-emitting unit 220 may have a hole mobility of 8.2 ⁇ 10 -4 cm 2 /(V ⁇ s).
  • the hole mobility of the second sub-layer BL12 of the exciton blocking layer BL1 of 210 may be 5.4 ⁇ 10 -5 cm 2 /(V ⁇ s).
  • the triplet energies respectively configured by the first sub-layer BL11 and the second sub-layer BL12 of the first exciton blocking layer BL1 may be different.
  • the configured triplet energy of the first sub-layer BL11 may be greater than the configured triplet energy of the second sub-layer BL12.
  • the difference between the configured triplet energy of the first sub-layer BL11 and the configured triplet energy of the second sub-layer BL12 may be less than 0.5 eV.
  • the triplet energy of the first sub-layer BL11 may be 2.54 eV
  • the triplet energy of the second sub-layer BL12 may be 2.48 eV
  • the first sub-layer BL11 is configured with a triplet energy
  • the second sub-layer BL12 The difference between configured triplet energies can be 0.06eV.
  • the triplet energies respectively configured by the first sub-layer BL21 and the second sub-layer BL22 of the second exciton blocking layer BL2 may also be different.
  • the configured triplet energy of the first sub-layer BL21 may be greater than the configured triplet energy of the second sub-layer BL22.
  • the difference between the configured triplet energy of the first sub-layer BL21 and the configured triplet energy of the second sub-layer BL22 may be less than 0.5 eV.
  • the triplet energy of the first sub-layer BL21 may be 2.52 eV
  • the triplet energy of the second sub-layer BL22 may be 2.45 eV
  • the first sub-layer BL21 is configured with a triplet energy
  • the second sub-layer BL22 The difference between configured triplet energies can be 0.07eV.
  • LUMO in Table 1 represents the lowest unoccupied molecular orbital (Lowest Unoccupied Molecular Orbital) energy level; the hole mobility is the hole mobility corresponding to each material when the electric field is 5000N/C.
  • the molecular structural formula of material A can be referred to Figure 12
  • the molecular structural formula of material B can be referred to Figure 13
  • the molecular structural formula of material C can be referred to Figure 14
  • the molecular structural formula of material D can be referred to Figure 15.
  • the molecular structural formulas of materials A to D all satisfy general formula 1.
  • the structure of general formula 1 can be referred to Figure 16.
  • L1, L2 and L3 in Figure 16 can be benzene or biphenyl.
  • n1, n2 and n3 can be 0 or 1.
  • N nitrogen atom
  • n1, n2 and n3 are all 0, N (nitrogen atom) is directly connected to the R substituent; when n1, n2 and n3 are all 1, N is connected to the R substituent through L1 ⁇ L3; in addition, n1, n2 and n3 may not be equal.
  • n1 when n1 is 0, it corresponds to the connection relationship between R1 and N when n1, n2 and n3 are all 0; when n1 is 1, it corresponds to the connection relationship between R1 and N when n1, n2 and n3 are all 1. connection relationship.
  • R1, R2 and R3 can be any one of benzene, biphenyl, naphthalene, adamantane, dibenzofuran, dibenzothiophene, dimethylfluorene, diphenylfluorene, spirofluorene or spiroxanthene .
  • the substituents in R1, R2 and R3 may be deuterium atoms, alkyl groups containing 1 to 4 C or benzene.
  • the exciton blocking layer BL can be made of any one or more materials from materials A to D.
  • material B is used to prepare the first sub-layer
  • material A is used to prepare the second sub-layer.
  • the material of the light-emitting layer corresponding to each light-emitting unit may be the same.
  • the first light-emitting layer EML1 may include a first host material and a light-emitting material.
  • the second luminescent layer EML2 may also include a first host material and a luminescent material.
  • the first host material may be a wide bandgap material, and the wide bandgap material may be a compound including at least one group selected from the group consisting of carbazolyl group, carboline group, spirofluorenyl group, fluorenyl group, silicon group, and phosphineoxy group.
  • Luminescent materials can be phosphorescent materials and fluorescent materials. For example, green light emitting materials and red light emitting materials.
  • the proportion of the luminescent material in the first host material is 4% to 15%.
  • the luminescent material may be a phosphorescent material
  • the first host material may be a wide bandgap material
  • the ratio of the phosphorescent material to the wide bandgap material ranges from 4% to 15%. For example, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%. Doping the first host material with a luminescent material and adjusting the proportion of the luminescent material in the first host material can improve the luminous efficiency of the luminescent layer.
  • the ratio of the first host material to the luminescent material in the first luminescent layer EML1 may be different from the ratio of the first host material to the luminescent material in the second luminescent layer EML2.
  • the proportion of the light-emitting material of the second light-emitting layer EML2 in the first host material of the second light-emitting layer EML2 may be greater than, less than, or equal to the proportion of the light-emitting material of the first light-emitting layer EML1 in the first host material of the first light-emitting layer EML1 proportion of .
  • the proportion of the luminescent material of the second luminescent layer EML2 in the first host material of the second luminescent layer EML2 is greater than the proportion of the luminescent material of the first luminescent layer EML1 in the first host material of the first luminescent layer EML1 proportion of .
  • the proportion of the luminescent material of the second luminescent layer EML2 in the first host material of the second luminescent layer EML2 is at most the proportion of the luminescent material of the first luminescent layer EML1 in the first host material. 3 times. That is, the proportion of the luminescent material of the second luminescent layer EML2 in the first host material of the second luminescent layer EML2 is the same as the proportion of the luminescent material of the first luminescent layer EML1 in the first host material of the first luminescent layer EML1
  • the ratio of the ratio is in the range of 1 to 3. For example 1, 2 or 3. Such an arrangement can improve the life of the light-emitting device.
  • the light extraction layer CPL covers the light emitting device layer LDL.
  • the light extraction layer CPL is directly located on the second electrode CE.
  • the light extraction layer CPL can improve the light extraction efficiency of the light emitting device layer LDL.
  • the light extraction layer CPL has a larger refractive index and a smaller light absorption coefficient.
  • the size of the light extraction layer CPL in the first direction X may be in the range of 50 nm ⁇ 80 nm.
  • the refractive index of the light extraction layer CPL at a wavelength for light of 460 nm may be greater than or equal to 1.8.
  • 1.8, 1.9, 2.0, 2.1, etc. are not limited here.
  • the encapsulation layer TFE is used to encapsulate the light emitting functional layer LDL and the light extraction layer CPL.
  • the encapsulation layer TFE may include a stacked first encapsulation layer ENL1, a second encapsulation layer ENL2, and a third encapsulation layer ENL3.
  • the first encapsulation layer ENL1 and the third encapsulation layer ENL3 are made of inorganic materials.
  • the above-mentioned inorganic materials are selected from silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, oxide At least one of silicon, aluminum oxide, titanium oxide, tin oxide, cerium oxide, silicon oxynitride (SiON) or lithium fluoride.
  • the second encapsulation layer ENL2 is made of organic materials.
  • the above-mentioned organic materials are acrylic resin, methacrylic resin, polyisoprene, vinyl resin, epoxy resin, polyurethane resin, cellulose resin or diethylene resin. At least one kind of rylene resin. Those skilled in the art can change the number of layers, materials and structure of the thin film encapsulation layer TFE as needed, and the present disclosure is not limited thereto.
  • This disclosure provides 7 groups of solutions for comparison.
  • the structure of the light-emitting device is shown in Figure 11.
  • the parameters of the 7 groups of schemes are detailed in Table 2.
  • GD ratio (EML1) in Table 2 is the proportion of the luminescent material of the first luminescent layer EML1 in the first host material of the first luminescent layer EML1; GD ratio (EML2) is the proportion of the luminescent material of the second luminescent layer EML1 in The proportion of the first host material of the second light-emitting layer EML2; PD ratio (HIL) is the proportion of P-type doping material in the third host material; PD ratio (P-CGL) is the P-type doping material The proportion of material in the second body material.
  • Table 3 shows the voltage, efficiency, color coordinate X, color coordinate Y and lifespan corresponding to the seven groups of solutions in Table 2.
  • the first sub-layer of the first exciton blocking layer is made of material B, and the second sub-layer is made of material A; the first sub-layer of the second exciton blocking layer is made of material D, and the second sub-layer is made of material C.
  • the first sub-layer of the first exciton blocking layer is made of material D, and the second sub-layer is made of material C; the first sub-layer of the second exciton blocking layer is made of material B, and the second sub-layer is made of material A.
  • the hole mobility of the first exciton blocking layer of the first light-emitting device when the hole mobility of the first exciton blocking layer of the first light-emitting device is lower than the mobility of the second exciton blocking layer, and the first exciton blocking layer of the second light-emitting device has When the hole mobility of the sub-blocking layer is higher than the hole mobility of the second exciton blocking layer, the luminous efficiency of the first light-emitting device and The lifespan is better than the luminous efficiency and lifespan of the second light-emitting device. From this, it can be obtained that the luminous efficiency and lifetime of a light-emitting device in which the hole mobility of the first exciton blocking layer is low and the hole mobility of the second exciton blocking layer is high are better than those of the first exciton blocking layer. Luminous efficiency and lifetime of a light-emitting device with high hole mobility and low hole mobility of the second exciton blocking layer.
  • the thickness of the first sub-layer gradually increases and the thickness of the second sub-layer gradually decreases.
  • the luminous efficiency of the light-emitting device first increases and then decreases.
  • the luminous efficiency of the light-emitting device reaches a higher value. Therefore, it can be obtained that when the thickness of the first sub-layer and the thickness of the second sub-layer are equal, the luminous efficiency of the light-emitting device is better.
  • the thickness of the first sub-layer gradually increases and the thickness of the second sub-layer gradually decreases. Under other conditions being equal, the life of the light-emitting device first increases and then decreases. When the thickness of the first sub-layer and the thickness of the second sub-layer are equal, the lifetime of the light-emitting device reaches a higher value. Therefore, it can be obtained that when the thickness of the first sub-layer and the thickness of the second sub-layer are equal, the life of the light-emitting device is longer.
  • the driving voltage and lifetime of the light-emitting device gradually decrease as the proportion of the light-emitting material in the second light-emitting layer EML2 in the first host material in the second light-emitting layer gradually decreases; the luminous efficiency of the light-emitting device As the proportion of the luminescent material in the second luminescent layer EML2 to the first host material in the second luminescent layer gradually decreases, it gradually increases.
  • the driving voltage of the light-emitting device gradually decreases as the proportion of the P-type dopant material in the P-type charge generation sub-layer to the second host material in the P-type charge generation sub-layer gradually increases;
  • the luminous efficiency and lifetime of the light-emitting device gradually increase as the proportion of the P-type dopant material in the P-type charge generation sub-layer to the second host material in the P-type charge generation sub-layer gradually increases.
  • the light-emitting device can improve the exciton blocking layer blocking by arranging the exciton blocking layer BL in the light-emitting unit as a double-layer structure in which the first sub-layer and the second sub-layer are stacked.
  • the properties of electrons can facilitate the exciton recombination region of the first light-emitting layer EML1 and the exciton recombination region of the second light-emitting layer EML2 to be as close as possible, thereby improving the luminous efficiency of the light-emitting device.
  • It can also realize low-voltage driving of light-emitting devices and extend the service life of light-emitting devices.
  • the present disclosure also provides a method for manufacturing a light-emitting device.
  • the production method includes steps S310 to S330.
  • Step S310 Form a first electrode.
  • step S310 it may also include providing a base substrate SUB.
  • the material of the base substrate SUB may be, for example, polyethylene terephthalate (PET), polyimide (PI), cycloolefin polymer (Cyclo Olefin Polymer, COP), etc.
  • the base substrate SUB may include a first sub-pixel area P1, a second sub-pixel area P2, and a third sub-pixel area P3.
  • the specific introduction of the first sub-pixel area P1, the second sub-pixel area P2 and the third sub-pixel area P3 has been described in detail before and will not be described again here.
  • a pixel circuit layer is formed on the base substrate SUB.
  • the pixel circuit layer includes a plurality of pixel circuits S. The specific introduction of the multiple pixel circuits S has been described in detail before and will not be described again here.
  • an insulating layer INL covering the plurality of pixel circuits is formed.
  • the first electrode may be an anode AE, and the anode AE may be formed on the insulating layer INL through a patterning process.
  • the anode AE can be made of metals and mixtures thereof such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir or Cr, or it can also be made of conductive metal oxide materials such as ITO, IZO or IGZO. production.
  • the anode may include a stacked composite structure of transparent conductive oxide/metal/transparent conductive oxide.
  • the transparent conductive oxide material is, for example, ITO or IZO
  • the metal material is, for example, Au, Ag, Ni or Pt.
  • the anode structure is: ITO/Ag/ITO.
  • the anode AE may include a first anode AE1, a second anode AE2, and a third anode AE3.
  • the first anode AE1 is located in the first sub-pixel area P1
  • the second anode AE2 is located in the second sub-pixel area P2
  • the third anode AE3 is located in the third sub-pixel area P3.
  • a pixel defining layer may also be formed on the anode.
  • the pixel defining layer is provided with a plurality of light-emitting openings, and the light-emitting openings expose the first electrode.
  • the pixel defining layer PDL may be formed on the insulating layer and the anode AE.
  • a deposition process is used to form a layer of pixel definition material covering the insulating layer and the anode AE, and part of the pixel definition material layer is removed through an etching process to obtain the pixel definition layer PDL.
  • the pixel definition layer PDL includes a first light-emitting opening K1 covering the first sub-pixel area P1, a second light-emitting opening K2 covering the second sub-pixel area P2, and a third light-emitting opening K3 covering the third sub-pixel area P3.
  • the first light-emitting opening K1 exposes the first anode AE1
  • the second light-emitting opening K2 exposes the second anode AE2
  • the third light-emitting opening K3 exposes the third anode AE3.
  • Step S320 Form at least two light-emitting units on the first electrode.
  • At least one light-emitting unit includes a light-emitting layer and an exciton blocking layer located on a side of the light-emitting layer close to the first electrode.
  • the exciton blocking layer includes a first sub-layer and a second sub-layer stacked on each other in a first direction.
  • the same light-emitting device may include a first light-emitting unit and a second light-emitting unit, and the first light-emitting unit and the second light-emitting unit are sequentially in the first direction X. form.
  • the first light-emitting unit may include a first hole injection layer HIL1 , a first hole transport layer HTL1 , an exciton blocking layer BL1 , a first light-emitting layer EML1 , and a second transport layer TL2 .
  • a hole injection material is evaporated on the pixel definition layer PDL and the first electrode in each light-emitting opening to form a first hole injection layer HIL1.
  • a hole transport material is evaporated on the first hole injection layer HIL1 to form the first hole transport layer HTL1.
  • Carbazole materials with higher hole mobility can be used as hole transport materials.
  • the exciton blocking layer includes a first sub-layer and a second sub-layer, and both the first sub-layer and the second sub-layer may cover the first light-emitting opening K1 , the second light-emitting opening K2, the third light-emitting opening K3 and the film of the non-light-emitting area P4 between adjacent openings.
  • a layer covering the first light-emitting opening K1 , the second light-emitting opening K2 , the third light-emitting opening K3 and adjacent openings is formed on the first hole transport layer HTL1
  • a first sub-layer BL11 covering the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the non-light-emitting area P4 between adjacent openings is formed on the second sub-layer BL12.
  • the positions of the first sub-layer and the second sub-layer may be reversed. That is to say, the first sub-layer can be prepared first and then the second sub-layer.
  • a first sub-layer covering the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the non-light-emitting area P4 between adjacent openings may be formed on the first hole transport layer HTL1.
  • a second sub-layer covering the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the non-light-emitting area P4 between adjacent openings is formed on the first sub-layer.
  • a first luminescent layer EML1 covering the first luminescent opening K1 , a first luminescent layer EML1 covering the second luminescent opening K2 , and a third luminescent layer EML1 covering the third luminescent opening K3 may be formed on the exciton blocking layer.
  • the first light-emitting layers EML1 in two adjacent light-emitting openings are independent of each other.
  • a second transport layer TL2 covering the first light-emitting layer and the exciton blocking layer is formed.
  • the second transmission layer TL2 may also cover the pixel defining layer PDL, and the part covering the pixel defining layer PDL and the part covering the light-emitting opening form a continuous film.
  • the second transport layer TL2 includes a first electron transport layer ETL1 and a first electron injection layer EIL1.
  • the steps of forming the second transmission layer may include:
  • an electron transport material is evaporated on the first luminescent layer EML1 to form a first electron transport layer ETL1 covering the first luminescent layer and the exciton blocking layer.
  • the electron transport material can use triazine materials with higher electron mobility.
  • the size of the first electron transport layer ETL1 in the first direction X may be between 5 nm and 50 nm.
  • the size of the first electron injection layer EIL1 in the first direction X may be between 0.5 nm and 20 nm.
  • the first light emitting unit 210 may further include forming the charge generation layer 300.
  • the charge generation layer 300 may cover the first, second, and third light emitting openings K1, K2, K3, and the pixel defining layer PDL. That is, the charge generation layer 300 covers the second transport layer TL2.
  • the second light emitting unit 220 includes a third transmission layer TL3, a second light emitting layer, and a fourth transmission layer TL4. Forming the second light emitting unit 220 may include:
  • a third transport layer TL3 covering the charge generation layer 300 is formed.
  • the third transmission layer TL3 can cover the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the pixel defining layer PDL, and the part covering the pixel defining layer PDL and the part covering the light-emitting opening form a continuous film .
  • the third transport layer TL3 includes a second hole injection layer HIL2 , a second hole transport layer HTL2 and a second exciton blocking layer BL2 .
  • Forming the third transport layer TL3 may include:
  • the second hole injection layer HIL2 may have the same structural features as the first hole injection layer HIL1, which will not be described again here.
  • the second hole transport layer HTL2 may have the same structural features as the first hole transport layer HTL1, which will not be described again here.
  • a second exciton blocking layer BL2 covering the second hole transport layer HTL2 is formed on the second hole transport layer HTL2.
  • the structure of the second exciton blocking layer BL2 may be the same as that of the first hole transport layer HTL2.
  • the exciton blocking layer BL1 has a double-layer structure with the same structure, and the structure of the second exciton blocking layer BL2 may also be a single-layer structure having a different structure from the first exciton blocking layer BL1.
  • a second light-emitting layer covering the first light-emitting opening K1, a second light-emitting layer covering the second light-emitting opening K2, and a second light-emitting layer covering the third light-emitting opening K3 are formed on the third transmission layer TL3.
  • the second light-emitting layers in two adjacent light-emitting openings are independent of each other.
  • a fourth transmission layer TL4 of the second light-emitting layer covering the first light-emitting opening K1, the second light-emitting layer covering the second light-emitting opening K2, and the second light-emitting layer covering the third light-emitting opening K3 is formed.
  • the fourth transmission layer TL4 may also cover the pixel defining layer PDL, and the part covering the pixel defining layer PDL and the part covering the light-emitting opening form a continuous film.
  • the fourth transport layer TL4 includes a hole blocking layer HBL, a second electron transport layer ETL2, and a second electron injection layer EIL2.
  • the steps of forming the fourth transmission layer TL4 may include:
  • An open mask can be used to evaporate a third exciton blocking material on the second exciton blocking layer BL2 and the second light emitting layer in each light emitting opening to form the hole blocking layer HBL.
  • the electron transport material is evaporated on the hole blocking layer HBL to form the second electron transport layer ETL2.
  • the second electron transport layer ETL2 may have the same structural features as the first electron transport layer ETL1, which will not be described again here.
  • the electron injection material is evaporated on the second electron transport layer ETL2 to form the second electron injection layer EIL2.
  • the second electron injection layer EIL2 may have the same structural features as the first electron injection layer EIL1, which will not be described again here.
  • Step S330 Form second electrodes on at least two light-emitting units.
  • a second electrode covering the fourth transmission layer TL4 is formed.
  • the second electrode may cover the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the pixel defining layer PDL, and the part covering the pixel defining layer PDL and the part covering the light-emitting openings form a continuous film.
  • the second electrode may be the cathode CE, which may have semi-transmissive or transmissive properties.
  • the cathode CE may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca, LiF/Al, Mo, Ti, or compounds thereof or a mixture, such as a mixture of Ag and Mg.
  • step S330 it may also include forming a light extraction layer CPL on a side of the second electrode away from the base substrate SUB.
  • the exciton blocking layer in the prepared light-emitting device has a stacked structure including a first sub-layer and a second sub-layer, which can improve the electron blocking and blocking ability of the exciton blocking layer.
  • ability of excitons and can facilitate the exciton recombination region of the first luminescent layer and the second luminescent layer
  • the exciton recombination region of the optical layer EML2 is as close as possible, thereby improving the overall luminous efficiency of the light-emitting device.
  • forming a light-emitting unit on the first electrode in step S320 includes: steps S321 to step S323.
  • steps S321 to S323 may be to form the first light-emitting unit or to form the second light-emitting unit, which is not limited here.
  • Step S321 Use an open mask to evaporate the first exciton blocking material on the first electrode to form a second sub-layer.
  • steps S321 to S323 may be to form the first light-emitting unit, as shown in FIG. 3, FIG. 9, and FIG. 10.
  • Step S321 may include: using an open mask, forming a first hole transport layer HTL1 The first exciton blocking material is evaporated on the substrate to form a second sub-layer BL12 covering the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the non-light-emitting area P4 between adjacent openings.
  • steps S321 to S323 may be to form a second light-emitting unit, as shown in FIG. 3, FIG. 9, and FIG. 11.
  • Step S321 may include: using an open mask, forming a second hole transport layer HTL2 The first exciton blocking material is evaporated on the substrate to form a second sub-layer BL22 covering the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the non-light-emitting area P4 between adjacent openings.
  • Step S322 Use an open mask to evaporate a second exciton blocking material on the second sub-layer to form a first sub-layer.
  • the first sub-layer and the second sub-layer together form an exciton blocking layer.
  • steps S321 to S323 may be to form the first light-emitting unit, as shown in FIGS. 3, 9 and 10.
  • Step S322 may include: using an open mask to evaporate the second sub-layer BL12.
  • the second exciton blocking material is plated to form a first sub-layer BL11 covering the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the non-light-emitting area P4 between adjacent openings.
  • steps S321 to S323 may be to form the first light-emitting unit, as shown in FIG. 3, FIG. 9, and FIG. 11.
  • Step S322 may include: using an open mask, forming a second hole transport layer HTL2 A first exciton blocking material is evaporated on the substrate to form a first sub-layer BL21 covering the first light-emitting opening K1, the second light-emitting opening K2, the third light-emitting opening K3 and the non-light-emitting area P4 between adjacent openings.
  • Step S323 Use a high-precision metal mask to form a light-emitting layer covering the light-emitting opening, and the light-emitting layer is located on the first sub-layer.
  • steps S321 to S323 may be to form the first light-emitting unit, as shown in FIG. 3, FIG. 9, and FIG. 10, using a high-precision metal mask (Fine Metal Mask, FMM) to activate different light-emitting openings.
  • First luminescent materials of different colors are respectively evaporated on the sub-blocking layer to form the first luminescent material.
  • the first red luminescent material can be evaporated on the first sub-layer BL11 in the first luminescent opening K1 using a high-precision metal mask to form the first luminescent layer EML1 covering the first luminescent opening K1; and then , the first green light-emitting material can be evaporated on the first sub-layer BL12 in the second light-emitting opening K2 using a high-precision metal mask to form the first light-emitting layer EML1 covering the second light-emitting opening K2.
  • steps S321 to S323 may be to form the first light-emitting unit.
  • a high-precision metal mask is used to evaporate the first sub-layer BL21 of different light-emitting openings respectively. Plate second luminescent materials of different colors to form a second luminescent layer EML2.
  • a second red light-emitting material is evaporated using a high-precision metal mask to form the second light-emitting layer EML2 covering the first light-emitting opening K1; then, On the first sub-layer BL21 in the second light-emitting opening K2, a second green light-emitting material is evaporated using a high-precision metal mask to form a second light-emitting layer EML2 covering the second light-emitting opening K2.
  • the first red luminescent material and the second red luminescent material may be the same material or different materials; similarly, the first green luminescent material and the second green luminescent material may be the same material or different materials. materials; no restrictions are made here.
  • an open mask can be used to obtain common layers that connect and cover each light-emitting opening, such as the exciton blocking layer BL, the second transmission layer TL2, the third transmission layer TL3, and the fourth transmission layer TL4; using high precision
  • the metal mask can form the first light-emitting layer and the second light-emitting layer covering each light-emitting opening, thereby improving the position accuracy of the first light-emitting layer and the second light-emitting layer, and simultaneously improving the manufacturing efficiency of the light-emitting device.

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Abstract

一种发光器件及其制作方法和显示面板。发光器件包括沿第一方向依次叠置的第一电极、至少两个发光单元和第二电极。至少两个发光单元包括第一发光单元和第二发光单元，第二发光单元位于第一发光单元和第二电极之间。至少一个发光单元包括发光层、以及位于发光层靠近第一电极一侧的激子阻挡层。激子阻挡层包括在第一方向相互叠置的第一子层和第二子层。第一子层位于第二子层与发光层之间。其中，沿第一方向，第一子层的厚度小于第二子层的厚度，并且第一子层的最高已占轨道能级高于第二子层的最高已占轨道能级。本公开提供的发光器件能够使得各发光单元分别对应的发光层的激子复合区域尽可能接近，从而提高发光器件的发光效率。

Description

发光器件及其制作方法和显示面板
本申请要求于2022年8月30日提交的、申请号为202211050994.9的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本公开涉及显示技术领域，尤其涉及一种发光器件及其制作方法和显示面板。
背景技术
有机电致发光器件(Organic Light Emitting Diode，OLED)因具有自发光、亮度高、对比度高、响应速度快、视角宽、结构简单以及柔性显示等诸多优点，受到企业和高校的重视，并获得飞速地发展。
由此，串联式有机电致发光器件(Tandem OLED)在OLED的发展中应运而生。Tandem OLED具备高亮度的优点。然而，相关技术中的Tandem OLED存在两个发光单元的出光效率不一致的问题。
发明内容
本公开一些实施例的目的在于提供一种发光器件及其制作方法和显示面板，能够提高发光器件的发光效率。
一方面，提供了一种发光器件。发光器件包括沿第一方向依次叠置的第一电极、至少两个发光单元和第二电极。所述至少两个发光单元包括第一发光单元和第二发光单元，所述第二发光单元位于所述第一发光单元和所述第二电极之间。所述至少两个发光单元中的至少一个发光单元包括发光层、以及位于所述发光层靠近所述第一电极一侧的激子阻挡层。所述激子阻挡层包括在所述第一方向相互叠置的第一子层和第二子层。所述第一子层位于所述第二子层与所述发光层之间。其中，沿所述第一方向，所述第一子层的厚度小于所述第二子层的厚度，并且所述第一子层的最高已占轨道能级高于所述第二子层的最高已占轨道能级。
在一些实施例中，所述第二子层的厚度至多为所述第一子层的厚度的6倍。
在一些实施例中，所述第一子层的最高已占轨道能级与所述第二子层的最高已占轨道能级之间的差值的绝对值小于1eV。
在一些实施例中，所述第一子层的空穴迁移率小于所述第二子层的空穴迁移率。
在一些实施例中，所述第二子层的空穴迁移率，至多为所述第一子层的 空穴迁移率的100倍。
在一些实施例中，所述发光层包括第一主体材料和发光材料，所述发光材料在所述第一主体材料中所占的比例为4％～15％。
在一些实施例中，所述第一发光单元包括第一发光层，所述第二发光单元包括第二发光层，所述第一发光单元和所述第二发光单元均包括所述激子阻挡层。
在一些实施例中，所述第二发光层的发光材料在所述第二发光层的第一主体材料中所占的比例，大于所述第一发光层的发光材料在所述第一发光层的第一主体材料中所占的比例。
在一些实施例中，所述第二发光层的发光材料在所述第二发光层的第一主体材料中所占的比例，至多为所述第一发光层的发光材料在所述第一主体材料中所占的比例的3倍。
在一些实施例中，所述第一发光单元的激子阻挡层的第一子层的空穴迁移率，小于等于所述第二发光单元的激子阻挡层的第一子层的空穴迁移率。
在一些实施例中，所述第二发光单元的激子阻挡层的第一子层的空穴迁移率，至多为所述第一发光单元的激子阻挡层的第一子层的空穴迁移率的100倍。
在一些实施例中，所述发光器件还包括电荷产生层，所述电荷产生层位于所述第一发光单元和所述第二发光单元之间。
在一些实施例中，所述电荷产生层包括沿所述第一方向叠置的N型电荷产生子层和P型电荷产生子层，所述P型电荷产生子层位于所述N型电荷产生子层远离所述第一电极的一侧，所述P型电荷产生子层包括第二主体材料和P型掺杂材料，所述P型掺杂材料在所述第二主体材料中所占的比例为1％～6％。
在一些实施例中，所述第一发光单元包括所述激子阻挡层；所述第一发光单元还包括空穴注入层，所述空穴注入层位于所述第一发光单元中的第二子层靠近所述第一电极的一侧，所述空穴注入层包括第三主体材料和所述P型掺杂材料，所述P型掺杂材料在所述第三主体材料中所占的比例为1％～6％。
在一些实施例中，所述P型掺杂材料在所述第二主体材料中所占的比例，大于所述P型掺杂材料在所述第三主体材料中所占的比例。
在一些实施例中，所述P型掺杂材料在所述第二主体材料中所占的比例，和所述P型掺杂材料在所述第三主体材料中所占的比例的差值在0.8％～5％之间。
又一方面，提供了一种显示面板。显示面板包括像素界定层和多个发光器件。像素界定层开设有多个发光开口。所述多个发光器件分别覆盖所述多个发光开口，至少一个发光器件为上述发光器件。
又一方面，提供了一种发光器件的制作方法。发光器件的制作方法包括形成第一电极。在所述第一电极上形成至少两个发光单元。至少一个所述发光单元包括发光层、以及位于所述发光层靠近所述第一电极一侧的激子阻挡层。所述激子阻挡层包括在所述第一方向相互叠置的第一子层和第二子层。在所述至少两个发光单元上形成第二电极。
在一些实施例中，在所述第一电极上形成一个发光单元，包括利用开放式掩膜版，在所述第一电极上蒸镀第一激子阻挡材料，形成第二子层。利用所述开放式掩膜版，在所述第二子层上蒸镀第二激子阻挡材料，形成第一子层，所述第一子层和第二子层共同构成所述激子阻挡层。利用高精度金属掩膜版，形成覆盖所述发光开口的发光层，所述发光层位于所述第一子层上。
附图说明
为了更清楚地说明本公开中的技术方案，下面将对本公开一些实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本公开的一些实施例的附图，对于本领域普通技术人员来讲，还可以根据这些附图获得其他的附图。此外，以下描述中的附图可以视作示意图，并非对本公开实施例所涉及的产品的实际尺寸、方法的实际流程、信号的实际时序等的限制。
图1为根据一些实施例的发光器件的结构图；
图2根据一些实施例的显示面板的立体图；
图3根据图2所示实施例的显示面板沿着线A-A'的截面图；
图4～图8为根据一些实施例的显示面板中子像素的排列结构图；
图9为根据一些实施例的显示面板的截面图；
图10为图3中F区域在一些实施例中的放大图；
图11为图3中F区域在一些实施例中的放大图；
图12为根据一些实施例的发光器件中材料一的分子结构式图；
图13为根据一些实施例的发光器件中材料二的分子结构式图；
图14为根据一些实施例的发光器件中材料三的分子结构式图；
图15为根据一些实施例的发光器件中材料四的分子结构式图；
图16为根据一些实施例的发光器件中材料一至材料四的分子通式图；
图17为根据一些实施例的发光器件的制作方法的流程图；
图18为根据一些实施例的发光器件的制作方法的流程图。
具体实施方式
下面将结合附图，对本公开一些实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本公开一部分实施例，而不是全部的实施例。基于本公开所提供的实施例，本领域普通技术人员所获得的所有其他实施例，都属于本公开保护的范围。
除非上下文另有要求，否则，在整个说明书和权利要求书中，术语“包括(comprise)”及其其他形式例如第三人称单数形式“包括(comprises)”和现在分词形式“包括(comprising)”被解释为开放、包含的意思，即为“包含，但不限于”。在说明书的描述中，术语“一个实施例(one embodiment)”、“一些实施例(some embodiments)”、“示例性实施例(exemplary embodiments)”、“示例(example)”、“特定示例(specific example)”或“一些示例(some examples)”等旨在表明与该实施例或示例相关的特定特征、结构、材料或特性包括在本公开的至少一个实施例或示例中。上述术语的示意性表示不一定是指同一实施例或示例。此外，所述的特定特征、结构、材料或特点可以以任何适当方式包括在任何一个或多个实施例或示例中。
以下，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。在本公开实施例的描述中，除非另有说明，“多个”的含义是两个或两个以上。
在描述一些实施例时，可能使用了“耦接”和“连接”及其衍伸的表达。例如，描述一些实施例时可能使用了术语“连接”以表明两个或两个以上部件彼此间有直接物理接触或电接触。又如，描述一些实施例时可能使用了术语“耦接”以表明两个或两个以上部件有直接物理接触或电接触。然而，术语“耦接”或“通信耦合(communicatively coupled)”也可能指两个或两个以上部件彼此间并无直接接触，但仍彼此协作或相互作用。这里所公开的实施例并不必然限制于本文内容。
“A、B和C中的至少一个”与“A、B或C中的至少一个”具有相同含义，均包括以下A、B和C的组合：仅A，仅B，仅C，A和B的组合，A和C的组合，B和C的组合，及A、B和C的组合。
“A和/或B”，包括以下三种组合：仅A，仅B，及A和B的组合。
如本文中所使用，根据上下文，术语“如果”任选地被解释为意思是“当……时”或“在……时”或“响应于确定”或“响应于检测到”。类似 地，根据上下文，短语“如果确定……”或“如果检测到[所陈述的条件或事件]”任选地被解释为是指“在确定……时”或“响应于确定……”或“在检测到[所陈述的条件或事件]时”或“响应于检测到[所陈述的条件或事件]”。
本文中“适用于”或“被配置为”的使用意味着开放和包容性的语言，其不排除适用于或被配置为执行额外任务或步骤的设备。
另外，“基于”的使用意味着开放和包容性，因为“基于”一个或多个所述条件或值的过程、步骤、计算或其他动作在实践中可以基于额外条件或超出所述的值。
如本文所使用的那样，“约”、“大致”或“近似”包括所阐述的值以及处于特定值的可接受偏差范围内的平均值，其中所述可接受偏差范围如由本领域普通技术人员考虑到正在讨论的测量以及与特定量的测量相关的误差(即，测量系统的局限性)所确定。
如本文所使用的那样，“平行”、“垂直”、“相等”包括所阐述的情况以及与所阐述的情况相近似的情况，该相近似的情况的范围处于可接受偏差范围内，其中所述可接受偏差范围如由本领域普通技术人员考虑到正在讨论的测量以及与特定量的测量相关的误差(即，测量系统的局限性)所确定。例如，“平行”包括绝对平行和近似平行，其中近似平行的可接受偏差范围例如可以是5°以内偏差；“垂直”包括绝对垂直和近似垂直，其中近似垂直的可接受偏差范围例如也可以是5°以内偏差。“相等”包括绝对相等和近似相等，其中近似相等的可接受偏差范围内例如可以是相等的两者之间的差值小于或等于其中任一者的5％。
应当理解的是，当层或元件被称为在另一层或基板上时，可以是该层或元件直接在另一层或基板上，或者也可以是该层或元件与另一层或基板之间存在中间层。
本文参照作为理想化示例性附图的剖视图和/或平面图描述了示例性实施方式。在附图中，为了清楚，放大了层和区域的厚度。因此，可设想到由于例如制造技术和/或公差引起的相对于附图的形状的变动。因此，示例性实施方式不应解释为局限于本文示出的区域的形状，而是包括因例如制造而引起的形状偏差。例如，示为矩形的蚀刻区域通常将具有弯曲的特征。因此，附图中所示的区域本质上是示意性的，且它们的形状并非旨在示出设备的区域的实际形状，并且并非旨在限制示例性实施方式的范围。
随着Tandem OLED的发展，对Tandem OLED的发光效率的要求逐渐提高。如图1所示，Tandem OLED器件一般包括第一电极110、第二电极140 和至少两个发光单元(例如第一发光单元120和第二发光单元130)，第一发光单元120和第二发光单元130可以位于第一电极110和第二电极140之间。第一电极110可用来提供空穴、第二电极140可用来提供电子。其中，第一发光单元120包括第一发光层122和第一电子阻挡层121，第二发光单元130包括第二发光层132和第二电子阻挡层131。各电子阻挡层通过对电子进行阻挡，使得电子尽可能地停留在与其相邻的发光层中，从而提高发光层的发光效率。
如图1所示，在一些实施例中，第一发光层122的靠近第一电极110的一侧设置有电子阻挡层121，第二发光层132的靠近第一电极110的一侧也设置有电子阻挡层131。当电子自第二电极140向第一电极110的方向传输时。因为电子传输时受到传输势垒的影响，会使得第二发光层132中的存留的电子量多于第一发光层122中存留的电子量。
综上，第一发光层122中的电子量少于第二发光层132中的电子量。由此可知，第一发光层122中电子和空穴复合形成的激子量少于第二发光层132中电子和空穴复合形成的激子量。因为第一发光层122中的激子量和第二发光层132中的激子量不同，所以第一发光层122的激子复合区域和第二发光层132的激子复合区域不一样，使得第一发光层122的发光效率和第二发光层132的发光效率也不一样，造成发光器件中两个发光单元之间的光线匹配效果不佳，最终导致发光器件整体的发光效率较低。
为了解决发光器件整体的发光效率较低的问题，本公开提供了一种发光器件及其制作方法和显示面板。
图2为根据一些实施例的显示面板100的立体图。图3为根据图2所示实施例的显示面板100沿着线A-A'的截面图。如图2所示，显示面板100包括用于显示图像的显示区AA和不显示图像的非显示区SA，非显示区SA围绕在显示区AA的至少一侧(例如，一侧；又如，四周，即包括上下两侧和左右两侧)。在一些示例中，非显示区SA可以封闭包围显示区AA，可以在至少一个方向上位于显示区AA的外侧。上述显示面板100在平面图中可以具有矩形形状，也可以具有圆形、椭圆、菱形、梯形、正方形或其他根据显示需要的形状。
上述显示面板100可以应用于显示装置。例如，显示装置可以为平板计算机、智能电话、头戴式显示器、汽车导航单元、照相机、在车辆中提供的中心信息显示器(CID)、手表型电子装置或其他穿戴设备、个人数字助理(PDA)、便携式多媒体播放器(PMP)和游戏机的中小型电子装置，以及诸如电 视、外部广告牌、监控器、包含显示屏幕的家用电器、个人计算机和膝上型计算机的中大型电子装置。如上所述的电子装置可以代表用于应用显示装置的单纯示例，并且因此本领域普通技术人员可以认识到，在不脱离本公开的精神和范围的情况下，显示装置也可以是其他电子装置。
结合图2、图3和图9所示，本公开的一些实施例提供了一种显示面板100。显示面板100包括衬底SUB、发光器件层LDL、光取出层CPL和封装层TFE。
衬底SUB包括多个重复排列的像素单元区PU。每个像素单元区PU可以包括显示不同颜色的第一子像素区P1、第二子像素区P2和第三子像素区P3。示例性地，第一子像素区P1被配置为显示红色光，第二子像素区P2被配置为显示绿色光，第三子像素区P3被配置为显示蓝色光。
另外，像素单元区PU还可以包括非发光区P4。非发光区P4可以位于第一子像素区P1与第二子像素区P2之间、第二子像素区P2和第三子像素区P3之间、以及第三子像素区P3和第一子像素区P1之间。
在一些示例中，如图4～图6所示，一个像素单元区PU包括一个第一子像素区P1、一个第二子像素区P2和一个第三子像素区P3。一个第一子像素区P1、一个第二子像素区P2和一个第三子像素区P3可以沿第二方向Y相互间隔且重复性地排布于显示区AA内。
在一些示例中，如图7和图8所示，一个像素单元区PU中可以包括显示相同颜色的两个子像素区，显示相同颜色的两个子像素区可以相邻设置。例如，一个像素单元区PU内包括一个红色子像素区R、两个绿色子像素区G和一个蓝色子像素区B，其中，一个像素单元区PU内的两个绿色子像素区G可以相邻设置。
在一些示例中，一个像素单元区PU包括一个第一子像素区P1、两个第二子像素区P2和一个第三子像素区P3。一个第一子像素区P1、两个第二子像素区P2和一个第三子像素区P3可以沿第二方向Y相互间隔且重复性地排布于显示区AA内。在此情况下，非发光区P4还可以位于两个第二子像素区P2之间。
如图3所示，在一个像素单元区PU内，在第二方向(平行于衬底SUB的方向)Y上，第一子像素区P1具有第一宽度WL1，第二子像素区P2具有第二宽度WL2，第三子像素区P3具有第三宽度WL3。其中，第一宽度WL1、第二宽度WL2和第三宽度WL3可以彼此不同。
如图9所示，显示面板100可以包括位于衬底基板SUB上的多个像素电 路。在一个像素单元区PU中，可以包括第一像素电路S1、第二像素电路S2和第三像素电路S3。例如，第一像素电路S1位于第一子像素区P1内，第二像素电路S2位于第二子像素区P2内，第三像素电路S3位于第三子像素区P3内。又例如，第一像素电路S1、第二像素电路S2和第三像素电路S3中至少一者的薄膜晶体管可以位于非发光区P4内。
像素电路的结构包括多种，可以根据实际需要选择设置。示例性地，像素电路可以包括：至少两个晶体管(用T表示)和至少一个电容器(用C表示)。例如，像素电路S可以具有“2T1C”、“6T1C”、“7T1C”、“6T2C”或“7T2C”等结构。
第一像素电路S1、第二像素电路S2和第三像素电路S3中至少一者的薄膜晶体管可以是包括多晶硅的薄膜晶体管或包括氧化物半导体的薄膜晶体管。例如，当薄膜晶体管为包括氧化物半导体的薄膜晶体管时，可以具有顶栅的薄膜晶体管结构。薄膜晶体管可以和信号线连接，所述信号线包括但不限于栅极线、数据线和电源线。
如图9所示，显示面板100可以包括绝缘层INL，可以位于第一像素电路S1、第二像素电路S2和第三像素电路S3上。绝缘层INL可以具有平坦化的表面。绝缘层INL可以由有机层形成。例如，绝缘层INL可以包括丙烯酸树脂、环氧树脂、酰亚胺树脂或酯树脂等。绝缘层INL可以具有通孔，暴露第一像素电路S1、第二像素电路S2和第三像素电路S3的电极，以便实现电连接。
结合图3和图9所示，显示面板100可以包括位于衬底基板SUB上的发光器件层LDL和像素界定层PDL。像素界定层PDL可以在绝缘层INL上形成并限定出多个发光开口。例如像素界定层PDL包括位于第一子像素区P1的第一发光开口K1、位于第二子像素区P2的第二发光开口K2、以及位于第三子像素区P3的第三发光开口K3。发光器件层LDL形成有多个和像素电路S连接的发光器件，多个发光器件分别覆盖多个发光开口。在一个像素单元区PU内，发光器件包括第一发光器件LD1、第二发光器件LD2和第三发光器件LD3。例如，第一发光器件LD1覆盖第一发光开口K1，第二发光器件LD2可以覆盖第二发光开口K2，并且第三发光器件LD3可以覆盖第三发光开口K3。
如图3所示，在一些实施例中，多个发光开口包括至少一个发光开口单元KU。一个发光开口单元KU包括对应不同颜色的第一发光开口K1、第二发光开口K2和第三发光开口K3。
一个发光开口单元KU对应一个像素单元区PU，发光开口单元KU中发光开口的数量与像素单元区中子像素区的数量相等。一个发光开口单元KU中的多个发光开口一一对应一个像素单元区PU中的多个子像素区。
可以理解为，在一个发光开口单元KU内，可以包括一个或多个第一发光开口K1、一个或多个第二发光开口K2、一个或多个第三发光开口K3。
第一发光器件LD1可以覆盖第一发光开口K1，第二发光器件LD2可以覆盖第二发光开口K2，并且第三发光器件LD3可以覆盖第三发光开口K3。
在一些实施例中，发光器件可以包括沿第一方向(即垂直于衬底SUB的方向)X依次叠置的第一电极、至少两个发光单元200和第二电极。
在一些示例中，显示面板100为顶发射显示面板100。第一电极为反射电极可以反射光线，例如阳极；第二电极为透射电极可以透出光线，例如阴极。这样，在阳极和阴极之间形成了微腔结构。
在另一些示例中，显示面板100为底发射显示面板100。第一电极为透射电极可以透出光线，例如阳极；第二电极CE为反射电极可以反射光线，例如阴极。这样，在阳极和阴极之间形成了微腔结构。
如图9和图10所述，第一电极包括位于第一子像素区P1的第一电极AE1、位于第二子像素区P2的第一电极AE2和位于第三子像素区P3的第一电极AE3。
在一些实施例中，第一电极可以包括高功函数的材料，例如Ag、Mg、Al、Pt、Pd、Au、Ni、Nd、Ir或Cr的金属及其混合物材料制成，也可以由ITO、IZO或IGZO等透明导电氧化物材料制成。第一电极在第一方向X上的尺寸可以处于80nm～200nm的范围内。
在一些示例中，显示面板100为顶发射显示面板100。第一电极AE1可以包括透明导电氧化物/金属/透明导电氧化物这样的叠层复合结构。其中，透明导电氧化物材料例如为ITO或IZO，金属材料例如为Au、Ag、Ni或Pt。例如阳极结构为：ITO/Ag/ITO。其中，金属在第一方向X上的尺寸可以处于80nm～100nm的范围内；透明导电氧化物在第一方向X上的尺寸可以处于5nm～10nm的范围内。另外，第一电极对于可见光的平均反射率可以处于85％～95％的范围内。
在一些示例中，显示面板100为底发射显示面板100。第一电极可以包括ITO、IZO或IGZO等透明导电氧化物。
在一些实施例中，第二电极CE可以包括金属材料或合金材料。其中，金属材料例如为Al、Ag或Mg，合金材料例如为Mg：Ag合金或Al：Li合金。 示例性地，阴极包括Mg：Ag合金，其中，Mg元素与铝元素之间的比值可以处于3:7～1:9的范围内。
在一些示例中，显示面板100为顶发射显示面板100。第二电极在第一方向X上的尺寸可以处于10nm～20nm的范围内。第二电极CE在对于波长为530nm的光的透光率可以大于或等于50％，例如50％、55％、60％、65％等。
在另一些示例中，显示面板100为底发射显示面板100。第二电极CE在第一方向上的尺寸可以大于或等于80nm，例如80nm、85nm、90nm、95nm等。这样，能够确保第二电极CE作为反射的电极对光有较好的反射率。
如图9和图10所示，第二电极包括位于第一子像素区P1的第二电极CE1、位于第二子像素区P2的第二电极CE2和位于第三子像素区P3的第二电极CE3。
第一电极和第二电极之间的至少两个发光单元200可以在第一方向X上叠置。第一电极和第二电极CE之间的发光单元200的数量可以是两个、也可以是三个，还可以是其他数量，此处不作限定。
如图10所示，在一些示例中，第一电极AE和第二电极CE之间包括第一发光单元210和第二发光单元220，即第一电极AE和第二电极CE之间包括两个发光单元200。第一发光单元210可以与第一电极AE直接接触，第二发光单元220位于第一发光单元210与第二电极CE之间，第二发光单元220可以与第二电极CE直接接触。
第一发光单元210包括第一发光层EML1、第一传输层TL1和第二传输层TL2。第一传输层TL1位于第一发光层EML1和第一电极AE之间，可以理解地，第一传输层TL1在第一方向X上的尺寸等于第一电极AE和第一发光层EML1在第一方向上的间隔距离。第一传输层TL1被配置为从第一电极AE传输空穴至第一发光层EML1。第二传输层TL2位于第一发光层EML1与第二发光单元220之间，可以理解地，第二传输层TL2在第一方向X上的尺寸等于第一发光层EML1与第二发光单元220在第一方向X上的间隔距离。第二传输层TL2被配置为传输电子至第一发光层EML1。这样，空穴和电子在第一发光层EML1复合，使得第一发光层EML1发光。
第二发光单元220包括第二发光层EML2、第三传输层TL3和第四传输层TL4。第三传输层TL3位于第二发光层EML2和第一发光单元210之间，可以理解地，第三传输层TL3在第一方向X上的尺寸等于第一发光单元210与第二发光层EML2在第一方向X上的间隔距离。第三传输层TL3被配置为传输空穴至第二发光层EML2。第四传输层TL4位于第二发光层EML2与第 二电极CE之间，可以理解地，第四传输层TL4在第一方向X上的尺寸等于第二发光层EML2与第二电极CE在第一方向X上的间隔距离。第四传输层TL4被配置为从第二电极CE传输电子至第二发光层EML2。这样，空穴和电子在第二发光层EML2复合，使得第二发光层EML2发光。
如图10所示，在一些实施例中，发光器件还包括位于相邻两个发光单元200之间的电荷产生层300。示例性地，电荷产生层300包括沿第一方向叠置的N型电荷产生子层320和P型电荷产生子层310，P型电荷产生子层310位于N型电荷产生子层320远离第一电极AE的一侧。N型电荷产生子层320可以直接与第一发光单元210直接接触，例如N型电荷产生子层320与第二传输层TL2直接接触，将电子提供给第一发光单元210。P型电荷产生子层310可以直接与第二发光单元220直接接触，例如P型电荷产生子层320与第三传输层TL3直接接触，将空穴提供给第二发光单元220。
在一些示例中，上述第二传输层TL2被配置为传输电荷产生层300提供的电子至第一发光层EML1，以使第一电极AE提供的空穴和电荷产生层300提供的电子在第一发光层EML1复合发光。上述第三传输层TL3被配置为传输电荷产生层300提供的空穴至第二发光层EML2，以使电荷产生层300提供的空穴和第二电极CE提供的电子在第二发光层EML2复合发光。
电荷产生层300可以包括金属、非掺杂有机物、P型及N型掺杂构成的有机PN结或金属氧化物等，此处不作限定。
在一些实施例中，在同一发光器件内，第一发光层EML1发出的光线的波长，与第二发光层EML2发出的光线的波长之间的差值的绝对值可以小于等于10nm。例如10nm、8nm、5nm、3nm等。
可以理解地，同一发光器件内的两个发光单元200发出相同或相近的光线。这样，能够提高两个发光单元200光谱叠加的集中性，提高光线的色纯度、以及出光效率。
例如，发光器件为蓝色发光器件，蓝色发光器件内第一发光层EML1发出的光线的波长为460nm，蓝色发光器件内第二发光层EML2发出的光线的波长可以为450nm～470nm。这样，能够提高发光器件中波长相重合的波段对应光线的出光效率。
在一些实施例中，在同一发光器件内，第一发光层EML1发出的光线处于光谱峰值的波长，与第二发光层EML2发出的光线处于光谱峰值的波长之间的差异率小于5％。
可以理解地，同一发光器件内的两个发光单元200发出的两种光线，处 于光谱峰值的波长相同或相近。这样，能够提高两个发光单元200光谱叠加的集中性，提高光线的色纯度、以及出光效率。
例如，发光器件为红色发光器件，红色发光器件内第一发光层EML1发出的光线处于光谱峰值的波长为530nm，红色发光器件内第二发光层EML2发出的光线处于光谱峰值的波长可以为504nm～557nm。这样，能够提高发光器件中波长相重合的波段对应光线的出光效率。
如图10所示，在一些示例中，第一传输层TL1可以包括第一空穴注入层HIL1和第一空穴传输层HTL1。第一空穴注入层HIL1位于第一电极AE与第一空穴传输层HTL1之间，第一空穴注入层HIL1被配置为将第一电极AE的空穴注入到第一空穴传输层HTL1。第一空穴传输层HTL1位于第一空穴注入层HIL1和第一发光层EML1之间，第一空穴传输层HTL1被配置为将第一空穴注入层HIL1注入的空穴传输至第一发光层EML1，使得空穴在第一发光层EML1内与电子复合，实现第一发光层EML1的发光。
在一些示例中，第一空穴注入层HIL1可以包括第三主体材料和P型掺杂材料。第三主体材料可以包括聚(3,4-乙烯二氧噻吩)聚苯乙烯磺酸(PEDOT:PSS)、聚噻吩、聚苯胺、聚吡咯、铜酞菁、和4,4’,4”-三(N,N-苯基-3-碱性蓝)三苯胺(m-MTDATA)。P型掺杂材料可以是醌衍生物或轴烯化合物之一，但不限于此。P型掺杂剂的非限制性实例是醌衍生物，例如四氰基醌二甲烷(TCNQ)、2,3,5,6-四氟-四氰基-1,4-苯并醌二甲烷(F4-TCNQ)、4,4”,4”-((1E,1”E,1”E)-环丙烷-1,2,3-三亚基三(氰甲基亚基))-三(2,3,5,6-四氟苯甲腈)。
在一些实施例中，P型掺杂材料在第三主体材料中所占的比例为1％～6％。例如1％、2％、3％、4％、5％或者6％。如此，可通过控制P型掺杂材料在第三主体材料中所占的比例，来提高第一空穴注入层HIL1的空穴注入效率，从而提高传输至第一发光层EML1的空穴量，进而提高第一发光层EML1中的激子复合量，以提高第一发光层EML1的发光效率。
在一些实施例中，P型电荷产生子层310包括第二主体材料和P型掺杂材料。第二主体材料可以包括金属和非掺杂有机物等。其中，P型掺杂材料在第二主体材料中所占的比例为1％～6％。例如1％、2％、3％、4％、5％或者6％。
如此，可降低P型电荷产生子层310传输空穴的难度，以将空穴注入与P型电荷产生子层310相邻设置的膜层(例如第二空穴注入层HIL2)中，也就是通过提高穿过P型电荷产生子层310向第二电极CE运动的空穴量，来提高第二发光层EML2中的空穴量，从而提高第二发光层EML2中的激子复合量， 进而提高第二发光层EML2的发光效率。
在一些示例中，P型掺杂材料在第二主体材料中所占的比例，大于P型掺杂材料在第三主体材料中所占的比例。如此设置，可提高Tandem OLED中第一发光层EML1和第二发光层EML2的发光效率。
示例性地，P型掺杂材料在第二主体材料中所占的比例，和P型掺杂材料在第三主体材料中所占的比例的差值在0.8％～5％之间。例如，0.8％、1％、2％、3％或者4％。如此设置，可提高Tandem OLED中第一发光层EML1和第二发光层EML2的发光效率。
如图10所示，在一些示例中，第二传输层TL2可以包括第一电子传输层ETL1和第一电子注入层EIL1。第一电子注入层EIL1位于第一电子传输层ETL1与电荷产生层300之间，第一电子注入层EIL1被配置为将N型电荷产生子层320提供的电子注入到第一电子传输层ETL1。第一电子传输层ETL1位于第一电子注入层EIL1与第二发光层EML2之间，第一电子传输层ETL1被配置为将第一电子注入层EIL1注入的电子传输至第一发光层EML1，使得电子在第一发光层EML1内与空穴复合，实现第一发光层EML1的发光。
如图10所示，在一些示例中，第三传输层TL3可以包括第二空穴注入层HIL2和第二空穴传输层HTL2。第二空穴注入层HIL2位于电荷产生层300与第二空穴传输层HTL2之间，第二空穴注入层HIL2被配置为将P型电荷产生子层的空穴注入到第二空穴传输层HTL2。第二空穴传输层HTL2位于第二空穴注入层HIL2和第二发光层EML2之间，第二空穴传输层HTL2被配置为将第二空穴注入层HIL2注入的空穴传输至第二发光层EML2，使得空穴在第二发光层EML2内与电子复合，实现第二发光层EML2的发光。
如图10所示，在一些示例中，第四传输层TL4可以包括第二电子传输层ETL2和第二电子注入层EIL2。第二电子注入层EIL2位于第二电子传输层ETL2与第二电极CE之间，第二电子注入层EIL2被配置为将第二电极CE提供的电子注入到第二电子传输层ETL2。第二电子传输层ETL2位于第二电子注入层EIL2与第二发光层CE之间，第二电子传输层ETL2被配置为将第二电子注入层EIL2注入的电子传输至第二发光层EML2，使得电子在第二发光层EML2内与空穴复合，实现第二发光层EML2的发光。
如图10所示，在一些示例中，第四传输层TL4还可以包括空穴阻挡层HBL。空穴阻挡层HBL可以位于第二电子传输层ETL2和第二发光层EML2之间，空穴阻挡层HBL被配置为阻挡第二发光层EML2中的空穴向靠近第二电极CE的方向运动。
在一些实施例中，如图10和图11所示，至少两个发光单元中的至少一个发光单元还包括激子阻挡层。示例性地，当发光器件包括两个发光单元200时，可以是两个发光单元200中的任一个发光单元200包括激子阻挡层BL(BL1/BL2)，例如，第一发光单元210包括第一激子阻挡层BL1(例如图10)。又例如，第一发光单元210包括第一激子阻挡层BL1，第二发光单元220包括第二激子阻挡层BL2(例如图11)。其中，激子阻挡层可以位于发光单元的发光层靠近第一电极的一侧。
示例性地，如图10所示，第一激子阻挡层BL1包括在第一方向X相互叠置的第一子层BL11和第二子层BL12。第一子层BL11可以被配置为阻挡电子，第二子层BL12可以被配置为传输空穴。
需要说明的是，第一子层BL11和第二子层BL12之间的位置关系可以根据实际情况进行调整。例如，第一子层BL11可以位于第二子层BL12和第一发光层EML1之间，或者第二子层BL12位于第一子层BL11和第一发光层EML1之间。
在一些示例中，如图10所示，激子阻挡层BL1的第一子层BL11位于第一发光层EML1和第二子层BL12之间。第一子层BL11可被配置为既传输空穴，又阻挡电子和激子。第二子层BL12可被配置为传输空穴。
第二发光单元220包括电子阻挡层EBL，电子阻挡层EBL位于第二发光层EML2和第二空穴传输层HTL2之间。第一电极AE(例如阳极)提供的空穴，能够从第一电极AE向第二电极CE的方向传输。例如，第一电极AE所提供的空穴，在离开第一电极AE后，可以先来到第一发光单元210的第一激子阻挡层BL1，并能够依次穿过第二子层BL12和第一子层BL11，随后注入第一发光层EML1。注入第一发光层EML1中的一些空穴可与第一发光层EML1内的电子复合形成激子，以使得第一发光层EML1发光。第一发光层EML1中未与电子复合的部分空穴能够继续往第二发光单元220的方向传输。当空穴离开第一发光层EML1后，可依次穿过电荷产生层300和电子阻挡层EBL，并注入第二发光单元220的第二发光层EML2，能够与第二发光层EML2中的电子复合，以使得第二发光层EML2发光。
因为空穴传输时具有传输势垒，所以越靠近第二电极CE，所传输的空穴量越少。也就是说，空穴的传输量自第一电极AE向第二电极CE的方向逐渐减少。可以理解为，传输到第一子层BL11的空穴量小于传输第二子层BL12的空穴量。虽然空穴的传输量自第一电极AE向第二电极CE的方向逐渐减少，但是P型电荷产生子层310能够提供一些空穴，并将空穴注入第二发光层 EML2，从而能够在一定程度上减少第二发光层EML2因传输势垒而损失的空穴量。
第二电极CE(例如阴极)提供的电子，能够从第二电极CE向第一电极AE的方向传输。例如，第二电极CE提供的电子，在离开第二电极CE后，可以先注入第二发光单元220的第二发光层EML2，并与第二发光层EML2内的空穴复合形成激子。第二发光层EML2中未与空穴复合的电子能够继续往第一电极AE的方向传输。随后，电子可先穿过电子阻挡层EBL，虽然该电子阻挡层EBL能够阻挡电子，但是一些电子还是能够穿过电子阻挡层EBL并传输至第一发光单元210。再加上N型电荷产生子层320能够提供一些电子，并将电子注入第一发光单元210，因此，能够减少第一发光单元210因电子阻挡层EBL及传输势垒而损失的电子量。
其次，当电子传输至第一发光层EML1时，第一子层BL11能够对第一发光层EML1中的激子及电子进行阻挡，从而能够使得从第一发光层EML1中向第一电极AE运动的绝大多数电子停留在第一发光层EML1中。
图1中的电子阻挡层除了能够对第一发光层EML1中的电子进行阻挡外，还需要具备阻挡激子和传输空穴的能力，所以电子阻挡层的挡电子能力效果较差。第一发光层EML1中流失的电子还是较多，从而导致第一发光层EML1中存留的电子较少，如此，第一发光层EML1中存留的电子数量和第二发光层EML2中存留的电子数量差距有点大。
而本公开实施例中，如图10所示，在第一发光层EML1靠近第一电极AE设置激子阻挡层BL1时，因为激子阻挡层BL1是层叠设置的双膜层结构，而且第一子层BL11位于第一发光层EML1和第二子层BL12之间。因为第一子层BL11主要能够对第一发光层EML1中的电子进行阻挡，所以能够减少第一发光层EML1中电子的流失，从而提高第一发光层EML1中存留的电子量，以提高第一发光层EML1中复合的激子量。
如此，通过设置第一子层BL11和第二子层BL12的双膜层结构，能够提高对第一发光层EML1中的电子进行阻挡的性能，以减少第一发光层EML1中的电子流失量。从而提高第一发光层EML1中存留的电子量，进而提高第一发光层EML1中电子和空穴复合的激子量。此外，第一子层BL11还能够对第一发光层EML1中的激子进行阻挡，以使得激子尽可能地停留在第一发光层EML1，从而可进一步提高第一发光层EML1中存留的激子量，以使得第一发光层EML1中存留的激子量和第二发光层EML2中存留的激子量尽可能地接近，进而提高第一发光层EML1的发光效率，以使得第一发光层EML1 的发光效率和第二发光层EML2的发光效率尽可能一致。
在一些示例中，如图11所示，发光器件包括两个发光单元200，两个发光单元200均包括激子阻挡层BL。例如：第一发光单元210包括第一激子阻挡层BL1，第二发光单元220包括第二激子阻挡层BL2。
如图11所示，沿第一方向X，该发光器件依次包括第一电极AE、第一激子阻挡层BL1、第一发光层EML1、电荷阻挡层300、第二激子阻挡层BL2、第二发光层EML2及第二电极CE。
第一电极AE提供的空穴，在离开第一电极AE后，可以先来到第一激子阻挡层BL1，并能够依次穿过第二子层BL12和第一子层BL11，随后注入第一发光层EML1。注入第一发光层EML1中的一些空穴可与第一发光层EML1内的电子复合形成激子，以使第一发光层EML1发光。第一发光层EML1中未与电子复合的空穴能够继续往第二电极CE的方向传输。当空穴离开第一发光层EML1后，可以依次穿过电荷产生层300和第二激子阻挡层BL2，随后注入第二发光层EML2，以使得第二发光层EML2发光。
同理，空穴传输时具有传输势垒，能够减少传输至第二发光层EML2的空穴量。但是P型电荷产生子层310能够提供一些空穴，并将空穴注入第二发光层EML2，如此能够在一定程度上增加第二发光层EML2因传输势垒而损失的空穴量。
第二电极CE提供的电子，能够在离开第二电极CE后，可以注入第二发光单元220的第二发光层EML2，并与第二发光层EML2内的空穴复合形成激子。第二发光层EML2中未与空穴复合的电子能够继续往第一电极AE的方向传输。随后，电子可先穿过第二激子阻挡层BL2的第一子层BL21和第二子层BL22，因为第二激子阻挡层BL2的第一子层BL21具有较好的阻挡电子能力，所以大多数电子能够被阻挡在第二发光层EML2中，一些电子则能够穿过第二激子阻挡层BL2的第一子层BL21和第二子层BL22继续向第一电极AE的方向传输。当电子离开第二发光层EML2后，可以依次穿过电荷产生层300，随后注入第一发光层EML1，以使得第一发光层EML1发光。
电子传输时具有传输势垒，能够减少传输至第一发光层EML1的电子量。但是N型电荷产生子层320能够提供一些电子，并将电子注入第一发光层EML1，如此能够在一定程度上增加第一发光层EML1因传输势垒而损失的电子量。
其次，电子传输至第一发光层EML1时，第一激子阻挡层BL1的第一子层BL11能够对第一发光层EML1中的激子及电子进行阻挡，从而能够使得从 第一发光层EML1中向第一电极AE运动的绝大多数电子停留在第一发光层EML1中。
图1中当第一发光层122靠近第一电极110的一侧设置电子阻挡层121，第二发光层132靠近第一电极110的一侧也设置电子阻挡层131时，因为单层结构的电子阻挡层的挡电子能力效果较差。第一发光层122中流失的电子还是较多，从而导致第一发光层122中存留的电子较少，第一发光层122中存留的电子数量和第二发光层132中存留的电子数量差距有点大。
而本公开实施例中，如图11所示，在第一发光层EML1靠近第一电极AE的一侧设置第一激子阻挡层BL1，在第二发光层EML2靠近第一电极AE的一侧设置第二激子阻挡层BL2，并使得上述激子阻挡层均为双膜层结构。能够提高各发光单元中对电子的阻挡性能，这样通过减少各个发光单元的电子流失量，能够提高各个发光单元内发生复合的激子的数量，进而提升各个发光单元的发光效率，实现发光器件整体发光效率的提升。
如图10和图11所示，在一些示例中，激子阻挡层(例如BL1或BL2)的第一子层的厚度可小于第二子层的厚度。例如，沿第一方向X，第一激子阻挡层BL1的第一子层BL11的厚度可小于第一激子阻挡层BL1的第二子层BL12的厚度。其中，第一子层BL11的厚度范围可以为4nm～25nm，第二子层BL12的厚度可以为20nm～50nm。
示例性地，第二子层BL12的厚度至多为第一子层BL11的厚度的6倍。即，第二子层BL12的厚度与第一子层BL11的厚度的比值处于1～6的范围内，例如1、2、3、4、5、6。
如图10和图11所示，在一些示例中，同一激子阻挡层(例如BL1或BL2)中，第一子层的最高已占轨道(Highest Occupied Molecular Orbital，HOMO)能级高于第二子层的最高已占轨道能级。
空穴容易从HOMO能级较低的膜层跃迁到HOMO能级较高的膜层，但不容易从HOMO能级较高的膜层跃迁到HOMO能级较低的膜层。因此，使得第一子层的HOMO能级高于第二子层的HOMO能级，能够降低空穴从第二子层跃迁到第一子层的难度，从而提高了空穴的传输率，以使得更多的空穴能够成功跃迁到第一子层，进而提高了传输至第一子层的空穴量。
示例性地，第一子层的最高已占轨道能级与第二子层的最高已占轨道能级之间的差值的绝对值小于1eV。例如0eV、0.1eV、0.2eV、0.4eV、0.6eV、0.8eV、1eV。
在一些实施例中，同一激子阻挡层(例如BL1或BL2)中，第一子层还 被配置为传输空穴。第一子层的空穴迁移率可以大于第二子层的空穴迁移率，第一子层的空穴迁移率也可以等于第二子层的空穴迁移率，第一子层的空穴迁移率还可以小于第二子层的空穴迁移率。
在一些示例中，同一激子阻挡层(例如BL1或BL2)中，第一子层的空穴迁移率小于第二子层的空穴迁移率。如此设置，能够提高发光层的靠近第一电极侧的空穴迁移率。
示例性地，第一激子阻挡层BL1在相同的电场强度下，第二子层BL12的空穴迁移率，至多为第一子层BL11的空穴迁移率的100倍。即，第二子层BL12的空穴迁移率与第一子层BL11的空穴迁移率的比值处于1～100的范围内，例如1、2、3、4……98、99、100。
可以理解的是，可以根据发光器件的实际需求，灵活调整第一子层BL11的空穴迁移率和第二子层BL12的空穴迁移率之间的比例，以便于满足发光单元对于激子阻挡层的空穴迁移率的要求。
当发光器件的每个发光单元200都包括激子阻挡层时，不同发光单元200中的激子阻挡层BL的空穴迁移率可以相同也可以不同，此处不作限定。
如图11所示，在一些实施例中，第一发光单元210的第一激子阻挡层BL1的第一子层BL11的空穴迁移率，可以大于也可以小于等于第二发光单元220的第二激子阻挡层BL2的第一子层BL11的空穴迁移率。
示例性地，第一发光单元210的第一激子阻挡层BL1的第一子层BL11的空穴迁移率，小于等于第二发光单元220的第二激子阻挡层BL2的第一子层BL11的空穴迁移率，这样，可通过第一激子阻挡层BL1的第一子层BL11提高空穴传输至第一发光层EML1的难度，从而减少传输至第一发光层EML1的空穴量，进而减少空穴在第一发光层EML1内复合的激子数量。同时，还能够通过第二激子阻挡层BL2的第一子层BL21降低空穴传输至第二发光层EML2的难度，从而增加传输至第二发光层EML2的空穴量，进而增加空穴在第二发光层EML2内复合的激子数量。如此，便于使第二发光层EML2中与电子复合的空穴量接近第一发光层EML1中与电子复合的空血量，以使得第一发光层EML1的激子复合区域与第二发光层EML2的激子复合区域尽可能地接近，从而提高发光器件的发光效率。
示例性地，第二发光单元210的第二激子阻挡层BL2的第一子层BL21的空穴迁移率，至多为第一发光单元220的第一激子阻挡层BL1的第一子层BL11的空穴迁移率的100倍。即，第二激子阻挡层BL2的第一子层BL21的空穴迁移率与第一激子阻挡层BL1的第一子层BL11的空穴迁移率的比值处 于1～100的范围内。
例如，在相同电场强度下，第二发光单元220的激子阻挡层BL2的第一子层BL21的空穴迁移率可为1.5×10-4cm2/(V·s)，第一发光单元210的激子阻挡层BL1的第一子层BL11的空穴迁移率可为9.9×10-6cm2/(V·s)。
如图11所示，在一些实施例中，第一发光单元210的第一激子阻挡层BL1的第二子层BL12的空穴迁移率，可以大于也可以小于等于第二发光单元220的第二激子阻挡层BL2的第二子层BL22的空穴迁移率。
示例性地，当第一发光单元210的第一激子阻挡层BL1的第二子层BL12的空穴迁移率，小于等于第二发光单元220的第二激子阻挡层BL2的第二子层BL22的空穴迁移率时，可通过第一激子阻挡层BL1的第二子层BL12提高空穴传输至第一发光层EML1的难度，从而可减少传输至第一发光层EML1的空穴量。并能够通过第二激子阻挡层BL2的第二子层BL22降低空穴传输至第二发光层EML2的难度，从而增加传输至第二发光层EML2的空穴量。再加上电荷产生层300能够提供一些空穴给第二发光层EML2。如此，便于调整第二发光层EML2和第一发光层EML1对应的空穴量，以使得二者的空穴量尽可能地接近，从而提高发光器件的发光效率。
示例性地，第二发光单元210的第二激子阻挡层BL2的第二子层BL22的空穴迁移率，至多为第一发光单元220的第一激子阻挡层BL1的第二子层BL12的空穴迁移率的100倍。即，第二激子阻挡层BL2的第二子层BL22的空穴迁移率与第一激子阻挡层BL1的第二子层BL12的空穴迁移率的比值处于1～100的范围内。
例如，在相同电场强度下，第二发光单元220的激子阻挡层BL2的第二子层BL22的空穴迁移率可为8.2×10-4cm2/(V·s)，第一发光单元210的激子阻挡层BL1的第二子层BL12的空穴迁移率可为5.4×10-5cm2/(V·s)。
如图11所示，在一些实施例中，第一激子阻挡层BL1的第一子层BL11和第二子层BL12分别配置的三线态能量可不同。
在一些示例中，第一子层BL11被配置的三线态能量可大于第二子层BL12被配置的三线态能量。示例性地，第一子层BL11被配置的三线态能量和第二子层BL12被配置的三线态能量之间的差值可小于0.5eV。例如0.01eV、0.08eV、0.15eV、0.18eV……0.3eV、0.4eV或者0.5eV。
在一些示例中，第一子层BL11的三线态能量可为2.54eV，第二子层BL12的三线态能量可为2.48eV，第一子层BL11被配置的三线态能量和第二子层BL12被配置的三线态能量之间的差值可为0.06eV。
如图11所示，在一些实施例中，第二激子阻挡层BL2的第一子层BL21和第二子层BL22分别配置的三线态能量也可不同。
在一些示例中，第一子层BL21被配置的三线态能量可大于第二子层BL22被配置的三线态能量。示例性地，第一子层BL21被配置的三线态能量和第二子层BL22被配置的三线态能量之间的差值可小于0.5eV。例如0.01eV、0.08eV、0.15eV、0.18eV……0.3eV、0.4eV或者0.5eV。
在一些示例中，第一子层BL21的三线态能量可为2.52eV，第二子层BL22的三线态能量可为2.45eV，第一子层BL21被配置的三线态能量和第二子层BL22被配置的三线态能量之间的差值可为0.07eV。
本公开提供了四种材料进行对比，四种材料对应的各项参数详见表1。
表1
表1中的LUMO表示最低未占轨道(Lowest Unoccupied Molecular Orbital)能级；空穴迁移率为电场为5000N/C时，各材料分别对应的空穴迁移率。
其中，材料A的分子结构式可参考图12，材料B的分子结构式可参考图13，材料C的分子结构式可参考图14，材料D的分子结构式可参考图15。材料A至材料D的分子结构式均满足通式一。通式一的结构可参考图16。
图16中的L1、L2和L3可为苯或联苯。n1、n2和n3可为0或1。当n1、n2和n3均为0时，N(氮原子)和R取代基直接连接；当n1、n2和n3均为1时，N通过L1～L3和R取代基连接；另外，n1、n2和n3还可以不相等，例如n1为0时，对应上述n1、n2和n3均为0时R1与N的连接关系；n1为1时，对应上述n1、n2和n3均为1时R1与N的连接关系。
上述R1、R2和R3可为苯、联苯、萘、金刚烷、二苯并呋喃、二苯并噻吩、二甲基芴、二苯基芴、螺芴或螺氧杂蒽中的任意一种。当R1，R2和R3发生取代反应时，R1，R2和R3中的取代基可为氘原子、含1～4个C的烷基或苯。
激子阻挡层BL可选用材料A至材料D中的任一者或者多者材料进行制 备，例如：采用材料B制备第一子层，采用材料A制备第二子层。
在一些实施例中，每个发光单元对应的发光层的材料可以相同。示例性地，第一发光层EML1可以包括第一主体材料和发光材料。第二发光层EML2也可以包括第一主体材料和发光材料。其中，第一主体材料可为宽带隙材料，宽带隙材料可以为包括咔唑基、咔啉基、螺芴基、芴基、硅基、膦氧基中的至少一种基团的化合物。发光材料可为磷光材料和荧光材料。例如，绿光发光材料、红光发光材料。
在一些实施例中，发光材料在第一主体材料中所占的比例为4％～15％。示例性的，发光材料可为磷光材料，第一主体材料可为宽带隙材料，磷光材料与宽带隙材料的比值范围为4％～15％。例如4％、5％、6％、7％、8％、9％、10％、11％、12％、13％、14％或者15％。在第一主体材料中掺杂发光材料，并调节发光材料在第一主体材料中的比例，能够提高发光层的发光效率。
在一些实施例中，第一发光层EML1中的第一主体材料和发光材料的比例，与第二发光层EML2中的第一主体材料和发光材料的比例可以有所差别。
第二发光层EML2的发光材料在第二发光层EML2的第一主体材料中所占的比例，可以大于、小于或者等于第一发光层EML1的发光材料在第一发光层EML1的第一主体材料中所占的比例。
在一些示例中，第二发光层EML2的发光材料在第二发光层EML2的第一主体材料中所占的比例，大于第一发光层EML1的发光材料在第一发光层EML1的第一主体材料中所占的比例。
示例性地，第二发光层EML2的发光材料在第二发光层EML2的第一主体材料中所占的比例，至多为第一发光层EML1的发光材料在第一主体材料中所占的比例的3倍。即，第二发光层EML2的发光材料在第二发光层EML2的第一主体材料中所占的比例，与第一发光层EML1的发光材料在第一发光层EML1的第一主体材料中所占的比例的比值处于1～3的范围内。例如1、2或者3。如此设置，可提高发光器件的寿命。
如图3所示，光取出层CPL覆盖发光器件层LDL，例如光取出层CPL直接位于第二电极CE上。光取出层CPL可以提高发光器件层LDL的出光效率，光取出层CPL的折射率较大，吸光系数较小。
在一些示例中，光取出层CPL在第一方向X上的尺寸可以处于50nm～80nm的范围内。光取出层CPL在波长对于460nm的光的折射率可以大于或等于1.8。例如1.8、1.9、2.0、2.1等等，此处不作限定。
如图9所示，封装层TFE用于封装发光功能层LDL和光取出层CPL。在 一些实施例中，封装层TFE可以包括堆叠设置的第一封装层ENL1、第二封装层ENL2和第三封装层ENL3。例如，第一封装层ENL1和第三封装层ENL3由无机材料制成，上述的无机材料选自氮化硅、氮化铝、氮化锆、氮化钛、氮化铪、氮化钽、氧化硅、氧化铝、氧化钛、氧化锡、氧化铈、氮氧化硅(SiON)或氟化锂中的至少一种。又例如，第二封装层ENL2由有机材料制成，上述的有机材料为烯酸树脂、甲基丙烯酸树脂、聚异戊二烯，乙烯基树脂、环氧树脂、聚氨酯树脂、纤维素树脂或二萘嵌苯树脂中的至少一种。本领域技术人员可以根据需要改变薄膜封装层TFE的层数、材料和结构，本公开不限于此。
本公开提供了7组方案进行对比，发光器件的结构如图11所示，7组方案的参数详见表2。
表2
表2中的GD ratio(EML1)为第一发光层EML1的发光材料在第一发光层EML1的第一主体材料中所占的比例；GD ratio(EML2)为第二发光层EML1的发光材料在第二发光层EML2的第一主体材料中所占的比例；PD ratio(HIL)为P型掺杂材料在第三主体材料中所占的比例；PD ratio(P-CGL)为P型掺杂材料在第二主体材料中所占的比例。
表3为表2中7组方案对应的电压、效率、色坐标X、色坐标Y和寿命。
表3

表3续
可以从表2中看出，方案1～7中，方案4的激子阻挡层是单膜层结构，其余方案的激子阻挡层均为是双膜层结构。
从方案1、方案2和方案4可以看出，在其它条件相同的情况下，配备单膜层结构的激子阻挡层的发光器件所需的驱动电压较高，配备双膜层结构的激子阻挡层的发光器件所需的驱动电压较低。由此，可以得到双膜层结构的激子阻挡层相较于单膜层结构的激子阻挡层而言，能够降低发光器件的驱动电压的结论。
类似地，从方案1、方案2和方案4可以看出，在其它条件相同的情况下，配备单膜层结构的激子阻挡层的发光器件的发光效率，低于配备双膜层结构的激子阻挡层的发光器件的发光效率。由此，可以得到双膜层结构的激子阻挡层相较于单膜层结构的激子阻挡层而言，能够提高发光器件的发光效率的结论。
类似地，从方案1、方案2和方案4可以看出，在其它条件相同的情况下，配备单膜层结构的激子阻挡层的发光器件的寿命，低于配备双膜层结构的激子阻挡层的发光器件的寿命。由此，可以得到双膜层结构的激子阻挡层相较于单膜层结构的激子阻挡层而言，能够提高发光器件的寿命的结论。
方案1中第一激子阻挡层的第一子层采用材料B，第二子层采用材料A；第二激子阻挡层的第一子层采用材料D，第二子层采用材料C。方案3中第一激子阻挡层的第一子层采用材料D，第二子层采用材料C；第二激子阻挡层的第一子层采用材料B，第二子层采用材料A。结合表1可以理解为，方案1中第一激子阻挡层由空穴迁移率低的材料制备得到，且第二激子阻挡层由空穴迁移率高的材料制备得到；方案3中第一激子阻挡层由空穴迁移率高的材料制备得到，且第二激子阻挡层由空穴迁移率低的材料制备得到。从表3中可以看出，方案1的发光效率和寿命高于方案3的发光效率和寿命。也就是说，在其他条件相同的情况下，当第一发光器件的第一激子阻挡层的空穴迁移率低于第二激子阻挡层的迁移率，而第二发光器件的第一激子阻挡层的空穴迁移率高于第二激子阻挡层的空穴迁移率时，第一发光器件的发光效率和 寿命优于第二发光器件的发光效率和寿命。由此，可以得到，在第一激子阻挡层的空穴迁移率低且第二激子阻挡层的空穴迁移率高的发光器件的发光效率和寿命，优于第一激子阻挡层的空穴迁移率高且第二激子阻挡层的空穴迁移率低的发光器件的发光效率和寿命。
按照方案1、方案2和方案5的顺序可以看出，第一子层的厚度逐渐增加且第二子层的厚度逐渐减少。在其它条件相同的情况下，发光器件的发光效率先增加后减小。在第一子层的厚度和第二子层的厚度相等时，发光器件的发光效率达到较高值。由此，可以得到，当第一子层的厚度和第二子层的厚度相等时，发光器件的发光效率较好。
按照方案1、方案2和方案5的顺序可以看出，第一子层的厚度逐渐增加且第二子层厚度逐渐减少。在其它条件相同的情况下，发光器件的寿命先增加后减少。在第一子层的厚度和第二子层的厚度相等时，发光器件的寿命达到较高值。由此，可以得到，当第一子层的厚度和第二子层的厚度相等时，发光器件的寿命较长。
从方案1和方案6可以看出，在其它条件相同的情况下，随着第二发光层EML2中发光材料在第二发光层EML2中第一主体材料中所占比例的减少，发光器件的驱动电压和寿命逐渐降低，并且发光器件的发光效率逐渐提高。由此，可以得到，发光器件的驱动电压和寿命随着第二发光层EML2中发光材料在第二发光层中第一主体材料中所占比例的逐渐减少，而逐渐降低；发光器件的发光效率随着第二发光层EML2中发光材料在第二发光层中第一主体材料中所占比例的逐渐减少，而逐渐提高。
从方案1和方案7可以看出，在其它条件相同的情况下，随着P型电荷产生子层中P型掺杂材料在P型电荷产生子层中第二主体材料中所占的比例逐渐增加，发光器件的驱动电压逐渐降低，并且发光器件的发光效率和寿命逐渐提高。由此，可以得到，发光器件的驱动电压随着P型电荷产生子层中P型掺杂材料在P型电荷产生子层中第二主体材料中所占的比例的逐渐增加，而逐渐降低；发光器件的发光效率和寿命随着P型电荷产生子层中P型掺杂材料在P型电荷产生子层中第二主体材料中所占的比例的逐渐增加，而逐渐提高。
综上所述，本公开实施例提供的发光器件，通过将发光单元中的激子阻挡层BL设置为第一子层和第二子层叠置的双膜层结构，能够提高激子阻挡层阻挡电子的性能，能够便于第一发光层EML1的激子复合区域与第二发光层EML2的激子复合区域尽可能地接近，从而提高发光器件的发光效率。此外， 还能实现发光器件的低电压驱动并延长发光器件的使用寿命。
请参阅图17，本公开还提供了一种发光器件的制作方法。制作方法包括步骤S310～S330。
步骤S310：形成第一电极。
如图9所示，在步骤S310之前，还可以包括提供一衬底基板SUB。衬底基板SUB的材料例如可以是聚对苯二甲酸乙二酯(Polyethylene terephthalate，简称PET)、聚酰亚胺(Polyimide，简称PI)、环烯烃聚合物(Cyclo Olefin Polymer，简称COP)等。
衬底基板SUB可以包括第一子像素区P1、第二子像素区P2和第三子像素区P3。第一子像素区P1、第二子像素区P2和第三子像素区P3的具体介绍在之前已经详细说明，此处不作赘述。
在衬底基板SUB上形成像素电路层。像素电路层包括多个像素电路S。多个像素电路S的具体介绍在之前已经详细说明，此处不作赘述。
在形成多个像素电路S之后，形成覆盖多个像素电路的绝缘层INL。
在一些示例中，如图9所示，第一电极可以为阳极AE，阳极AE可以在绝缘层INL上，通过一次构图工艺形成。阳极AE可以由如Ag、Mg、Al、Pt、Pd、Au、Ni、Nd、Ir或Cr的金属及其混合物材料制成，也可以由ITO、IZO或IGZO等有导电性的金属氧化物材料制成。
在一些示例中，阳极可以包括透明导电氧化物/金属/透明导电氧化物这样的叠层复合结构。其中，透明导电氧化物材料例如为ITO或IZO，金属材料例如为Au、Ag、Ni或Pt。例如阳极结构为：ITO/Ag/ITO。
阳极AE可以包括第一阳极AE1、第二阳极AE2和第三阳极AE3。第一阳极AE1位于第一子像素区P1内，第二阳极AE2位于第二子像素区P2内，第三阳极AE3位于第三子像素区P3内。
在步骤S320之前，还可以在阳极上形成像素界定层，像素界定层开设有多个发光开口，发光开口暴露第一电极。
像素界定层PDL可以在绝缘层和阳极AE上形成。例如，利用沉积工艺形成一层覆盖绝缘层和阳极AE的像素界定材料层，并通过刻蚀工艺去除部分像素界定材料层，得到像素界定层PDL。像素界定层PDL包括覆盖第一子像素区P1的第一发光开口K1、覆盖第二子像素区P2的第二发光开口K2、以及覆盖第三子像素区P3的第三发光开口K3。
第一发光开口K1暴露第一阳极AE1，第二发光开口K2暴露第二阳极AE2，第三发光开口K3暴露第三阳极AE3。
步骤S320：在第一电极上形成至少两个发光单元。至少一个发光单元包括发光层、以及位于发光层靠近第一电极一侧的激子阻挡层。激子阻挡层包括在第一方向相互叠置的第一子层和第二子层。
如图3、图9及图10所示，在一些实施例中，同一发光器件可以包括第一发光单元和第二发光单元，第一发光单元和第二发光单元依次在第一方向X上依次形成。
在一些示例中，如图10所示，第一发光单元可以包括第一空穴注入层HIL1、第一空穴传输层HTL1、激子阻挡层BL1、第一发光层EML1、第二传输层TL2。
利用开放式掩膜版，在像素界定层PDL和各发光开口内的第一电极上蒸镀空穴注入材料，形成第一空穴注入层HIL1。
利用开放式掩膜版，在第一空穴注入层HIL1上蒸镀空穴传输材料，形成第一空穴传输层HTL1。空穴传输材料可以选用空穴迁移率较高的咔唑类材料。
形成覆盖第一空穴传输层HTL1的激子阻挡层，其中，激子阻挡层包括第一子层和第二子层，第一子层和第二子层均可以为覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的薄膜。
在一些示例中，如图3、图9及图10所示，在第一空穴传输层HTL1上形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第二子层BL12。
在第二子层BL12上形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第一子层BL11。
在一些示例中，第一子层和第二子层的位置可调换。也就是说，可以先制备第一子层再制备第二子层。
示例性地，可在第一空穴传输层HTL1上形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第一子层。
在第一子层上形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第二子层。
在形成激子阻挡层后，可在激子阻挡层上形成覆盖第一发光开口K1的第一发光层EML1、覆盖第二发光开口K2的第一发光层EML1和覆盖第三发光开口K3的第一发光层EML1。相邻两个发光开口内的第一发光层EML1相互独立。
在形成第一发光层之后，形成覆盖第一发光层和激子阻挡层的第二传输层TL2。其中，第二传输层TL2还可以覆盖像素界定层PDL，且覆盖像素界定层PDL的部分与覆盖发光开口的部分构成连续的薄膜。
在一些示例中，第二传输层TL2包括第一电子传输层ETL1和第一电子注入层EIL1。如图3、图9及图10所示，形成第二传输层的步骤可以包括：
利用开放式掩膜版，在第一发光层EML1上蒸镀电子传输材料，形成覆盖第一发光层和激子阻挡层的第一电子传输层ETL1。其中，电子传输材料可以选用电子迁移率较高的三嗪类材料。第一电子传输层ETL1在第一方向X上的尺寸可以处于5nm～50nm之间。
利用开放式掩膜版，在第一电子传输层ETL1上蒸镀电子注入材料，形成第一电子注入层EIL1。其中，第一电子注入层EIL1在第一方向X上的尺寸可以处于0.5nm～20nm之间。
在一些示例中，在形成第一发光单元210之后，还可以包括：形成电荷产生层300。电荷产生层300可以覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及像素界定层PDL。即，电荷产生层300覆盖第二传输层TL2。
在一些示例中，第二发光单元220包括第三传输层TL3、第二发光层和第四传输层TL4。形成第二发光单元220可以包括：
形成覆盖电荷产生层300的第三传输层TL3。其中，第三传输层TL3可以覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及像素界定层PDL，且覆盖像素界定层PDL的部分与覆盖发光开口的部分构成连续的薄膜。
在一些示例中，如图3、图9及图11所示，第三传输层TL3包括第二空穴注入层HIL2、第二空穴传输层HTL2和第二激子阻挡层BL2。形成第三传输层TL3可以包括：
利用开放式掩膜版，在电荷产生层300上蒸镀空穴注入材料，形成第二空穴注入层HIL2。第二空穴注入层HIL2可以与第一空穴注入层HIL1具有相同的结构特点，此处不作赘述。
利用开放式掩膜版，在第二空穴注入层HIL2上蒸镀空穴传输材料，形成第二空穴传输层HTL2。第二空穴传输层HTL2可以与第一空穴传输层HTL1具有相同的结构特点，此处不作赘述。
利用开放式掩膜版，在第二空穴传输层HTL2上形成覆盖第二空穴传输层HTL2的第二激子阻挡层BL2，第二激子阻挡层BL2的结构可以是与第一 激子阻挡层BL1具有相同的结构的双膜层结构，第二激子阻挡层BL2的结构也可以是与第一激子阻挡层BL1具有不同结构的单膜层结构。
在第三传输层TL3上形成覆盖第一发光开口K1的第二发光层、覆盖第二发光开口K2的第二发光层和覆盖第三发光开口K3的第二发光层。相邻两个发光开口内的第二发光层相互独立。
形成覆盖第一发光开口K1的第二发光层、覆盖第二发光开口K2的第二发光层和覆盖第三发光开口K3的第二发光层的第四传输层TL4。其中，第四传输层TL4还可以覆盖像素界定层PDL，且覆盖像素界定层PDL的部分与覆盖发光开口的部分构成连续的薄膜。
在一些示例中，第四传输层TL4包括空穴阻挡层HBL、第二电子传输层ETL2和第二电子注入层EIL2。如图3、图9及图11所示，形成第四传输层TL4的步骤，可以包括：
可利用开放式掩膜版，在第二激子阻挡层BL2和各发光开口内的第二发光层上蒸镀第三激子阻挡材料，形成空穴阻挡层HBL。
利用开放式掩膜版，在空穴阻挡层HBL上蒸镀电子传输材料，形成第二电子传输层ETL2。第二电子传输层ETL2可以与第一电子传输层ETL1具有相同的结构特点，此处不作赘述。
利用开放式掩膜版，在第二电子传输层ETL2上蒸镀电子注入材料，形成第二电子注入层EIL2。第二电子注入层EIL2可以与第一电子注入层EIL1具有相同的结构特点，此处不作赘述。
步骤S330：在至少两个发光单元上形成第二电极。
形成覆盖第四传输层TL4的第二电极。其中，第二电极可以覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及像素界定层PDL，且覆盖像素界定层PDL的部分与覆盖发光开口的部分构成连续的薄膜。
第二电极可以为阴极CE，阴极可以具有半透射或透射性质。在一些实施例中，阴极CE可以包括Ag、Mg、Cu、Al、Pt、Pd、Au、Ni、Nd、Ir、Cr、Li、Ca、LiF/Ca、LiF/Al、Mo、Ti或其化合物或混合物，例如Ag和Mg的混合物。
在一些示例中，在步骤S330之后，还可以包括在第二电极远离衬底基板SUB的一侧，形成光取出层CPL。
通过本实施例提供的发光器件的制作方法，制备得到的发光器件中的激子阻挡层为包括第一子层和第二子层的叠层结构，能够提高激子阻挡层的阻挡电子和阻挡激子的能力，并能够便于第一发光层的激子复合区域与第二发 光层EML2的激子复合区域尽可能地接近，从而提高发光器件整体的发光效率。
在一些实施例中，如图18所示，步骤S320中在第一电极上形成一个发光单元包括：步骤S321～步骤S323。其中，步骤S321～步骤S323可以是形成第一发光单元，也可以是形成第二发光单元，此处不作限定。
步骤S321：利用开放式掩膜版，在第一电极上蒸镀第一激子阻挡材料，形成第二子层。
在一些示例中，步骤S321～步骤S323可以是形成第一发光单元，如图3、图9及图10所示，步骤S321可以包括：利用开放式掩膜版，在第一空穴传输层HTL1上蒸镀第一激子阻挡材料，形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第二子层BL12。
在一些示例中，步骤S321～步骤S323可以是形成第二发光单元，如图3、图9及图11所示，步骤S321可以包括：利用开放式掩膜版，在第二空穴传输层HTL2上蒸镀第一激子阻挡材料，形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第二子层BL22。
步骤S322：利用开放式掩膜版，在第二子层上蒸镀第二激子阻挡材料，形成第一子层，第一子层和第二子层共同构成激子阻挡层。
在一些示例中，步骤S321～步骤S323可以是形成第一发光单元，如图3、图9及图10所示，步骤S322可以包括：利用开放式掩膜版，在第二子层BL12上蒸镀第二激子阻挡材料，形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第一子层BL11。
在一些示例中，步骤S321～步骤S323可以是形成第一发光单元，如图3、图9及图11所示，步骤S322可以包括：利用开放式掩膜版，在第二空穴传输层HTL2上蒸镀第一激子阻挡材料，形成覆盖第一发光开口K1、第二发光开口K2、第三发光开口K3以及相邻开口之间的非发光区P4的第一子层BL21。
步骤S323：利用高精度金属掩膜版，形成覆盖发光开口的发光层，发光层位于第一子层上。
在一些示例中，步骤S321～步骤S323可以是形成第一发光单元，如图3、图9及图10所示，利用高精度金属掩膜版(Fine Metal Mask，FMM)在不同发光开口的激子阻挡层上分别蒸镀不同颜色的第一发光材料，形成第一发光 层EML1。例如：首先，可在第一发光开口K1内的第一子层BL11上，利用高精度金属掩膜版蒸镀第一红色发光材料，形成覆盖第一发光开口K1的第一发光层EML1；之后，可在第二发光开口K2内的第一子层BL12上，利用高精度金属掩膜版蒸镀第一绿色发光材料，形成覆盖第二发光开口K2的第一发光层EML1。
在一些示例中，步骤S321～步骤S323可以是形成第一发光单元，如图3、图9及图11所示，利用高精度金属掩膜版在不同发光开口的第一子层BL21上分别蒸镀不同颜色的第二发光材料，形成第二发光层EML2。例如：首先，在第一发光开口K1内的第一子层BL21上，利用高精度金属掩膜版蒸镀第二红色发光材料，形成覆盖第一发光开口K1的第二发光层EML2；之后，在第二发光开口K2内的第一子层BL21上，利用高精度金属掩膜版蒸镀第二绿色发光材料，形成覆盖第二发光开口K2的第二发光层EML2。
其中，第一红色发光材料和第二红色发光材料可以是相同的材料，也可以是不同的材料；类似地，第一绿色发光材料和第二绿色发光材料可以是相同的材料，也可以是不同的材料；此处不作限定。
本实施例中，利用开放式掩膜版能够得到连通覆盖各个发光开口的公共层，例如激子阻挡层BL、第二传输层TL2、第三传输层TL3和第四传输层TL4；利用高精度金属掩膜版能够形成覆盖各个发光开口的第一发光层和第二发光层，从而提高第一发光层和第二发光层的位置精度，同时提高发光器件的制作效率。
以上所述，仅为本公开的具体实施方式，但本公开的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本公开揭露的技术范围内，想到变化或替换，都应涵盖在本公开的保护范围之内。因此，本公开的保护范围应以所述权利要求的保护范围为准。

Claims (19)

  1. 一种发光器件，包括：
    沿第一方向依次叠置的第一电极、至少两个发光单元和第二电极；
    所述至少两个发光单元包括第一发光单元和第二发光单元，所述第二发光单元位于所述第一发光单元和所述第二电极之间；
    所述至少两个发光单元中的至少一个发光单元包括发光层、以及位于所述发光层靠近所述第一电极一侧的激子阻挡层；所述激子阻挡层包括在所述第一方向相互叠置的第一子层和第二子层，所述第一子层位于所述第二子层与所述发光层之间；
    其中，沿所述第一方向，所述第一子层的厚度小于所述第二子层的厚度，并且所述第一子层的最高已占轨道能级高于所述第二子层的最高已占轨道能级。
  2. 根据权利要求1所述的发光器件，其中，所述第二子层的厚度至多为所述第一子层的厚度的6倍。
  3. 根据权利要求1或2所述的发光器件，其中，所述第一子层的最高已占轨道能级与所述第二子层的最高已占轨道能级之间的差值的绝对值小于1eV。
  4. 根据权利要求1～3中任一项所述的发光器件，其中，所述第一子层的空穴迁移率小于所述第二子层的空穴迁移率。
  5. 根据权利要求4所述的发光器件，其中，所述第二子层的空穴迁移率，至多为所述第一子层的空穴迁移率的100倍。
  6. 根据权利要求1～5中任一项所述的发光器件，其中，所述发光层包括第一主体材料和发光材料，所述发光材料在所述第一主体材料中所占的比例为4％～15％。
  7. 根据权利要求1～6中任一项所述的发光器件，其中，所述第一发光单元包括第一发光层，所述第二发光单元包括第二发光层，所述第一发光单元和所述第二发光单元均包括所述激子阻挡层。
  8. 根据权利要求7所述的发光器件，其中，所述第二发光层的发光材料在所述第二发光层的第一主体材料中所占的比例，大于所述第一发光层的发光材料在所述第一发光层的第一主体材料中所占的比例。
  9. 根据权利要求7或8所述的发光器件，其中，所述第二发光层的发光材料在所述第二发光层的第一主体材料中所占的比例，至多为所述第一发光层的发光材料在所述第一主体材料中所占的比例的3倍。
  10. 根据权利要求7～9中任一项所述的发光器件，其中，所述第一发光单元的激子阻挡层的第一子层的空穴迁移率，小于等于所述第二发光单元的激子阻挡层的第一子层的空穴迁移率。
  11. 根据权利要求10所述的发光器件，其中，所述第二发光单元的激子阻挡层的第一子层的空穴迁移率，至多为所述第一发光单元的激子阻挡层的第一子层的空穴迁移率的100倍。
  12. 根据权利要求1～11中任一项所述的发光器件，其中，所述发光器件还包括电荷产生层，所述电荷产生层位于所述第一发光单元和所述第二发光单元之间。
  13. 根据权利要求12所述的发光器件，其中，所述电荷产生层包括沿所述第一方向叠置的N型电荷产生子层和P型电荷产生子层，所述P型电荷产生子层位于所述N型电荷产生子层远离所述第一电极的一侧，所述P型电荷产生子层包括第二主体材料和P型掺杂材料，所述P型掺杂材料在所述第二主体材料中所占的比例为1％～6％。
  14. 根据权利要求13所述的发光器件，其中，所述第一发光单元包括所述激子阻挡层；所述第一发光单元还包括空穴注入层，所述空穴注入层位于所述第一发光单元中的第二子层靠近所述第一电极的一侧，所述空穴注入层包括第三主体材料和所述P型掺杂材料，所述P型掺杂材料在所述第三主体材料中所占的比例为1％～6％。
  15. 根据权利要求14所述的发光器件，其中，所述P型掺杂材料在所述第二主体材料中所占的比例，大于所述P型掺杂材料在所述第三主体材料中所占的比例。
  16. 根据权利要求15所述的发光器件，其中，所述P型掺杂材料在所述第二主体材料中所占的比例，和所述P型掺杂材料在所述第三主体材料中所占的比例的差值在0.8％～5％之间。
  17. 一种显示面板，包括：
    像素界定层，开设有多个发光开口；
    多个发光器件，所述多个发光器件分别覆盖所述多个发光开口，至少一个发光器件为如权利要求1～16中任一项所述的发光器件。
  18. 一种发光器件的制作方法，包括：
    形成第一电极；
    在所述第一电极上形成至少两个发光单元；至少一个所述发光单元包括发光层、以及位于所述发光层靠近所述第一电极一侧的激子阻挡层；所述激 子阻挡层包括在所述第一方向相互叠置的第一子层和第二子层；
    在所述至少两个发光单元上形成第二电极。
  19. 根据权利要求18所述的制作方法，其中，在所述第一电极上形成一个发光单元，包括：
    利用开放式掩膜版，在所述第一电极上蒸镀第一激子阻挡材料，形成第二子层；
    利用所述开放式掩膜版，在所述第二子层上蒸镀第二激子阻挡材料，形成第一子层，所述第一子层和第二子层共同构成所述激子阻挡层；
    利用高精度金属掩膜版，形成覆盖发光开口的发光层，所述发光层位于所述第一子层上。
PCT/CN2023/115302 2022-08-30 2023-08-28 发光器件及其制作方法和显示面板 WO2024046281A1 (zh)

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