WO2025218296A1 - 发光器件和显示面板 - Google Patents

发光器件和显示面板

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Publication number
WO2025218296A1
WO2025218296A1 PCT/CN2025/072988 CN2025072988W WO2025218296A1 WO 2025218296 A1 WO2025218296 A1 WO 2025218296A1 CN 2025072988 W CN2025072988 W CN 2025072988W WO 2025218296 A1 WO2025218296 A1 WO 2025218296A1
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WO
WIPO (PCT)
Prior art keywords
light
emitting
emitting device
layer
hole transport
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2025/072988
Other languages
English (en)
French (fr)
Other versions
WO2025218296A9 (zh
Inventor
黎俊聪
张继勇
高荣荣
陈磊
王丹
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BOE Technology Group Co Ltd
Chengdu BOE Optoelectronics Technology Co Ltd
Original Assignee
BOE Technology Group Co Ltd
Chengdu BOE Optoelectronics Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BOE Technology Group Co Ltd, Chengdu BOE Optoelectronics Technology Co Ltd filed Critical BOE Technology Group Co Ltd
Publication of WO2025218296A1 publication Critical patent/WO2025218296A1/zh
Publication of WO2025218296A9 publication Critical patent/WO2025218296A9/zh
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

Links

Classifications

    • 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]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • H10K50/13—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit
    • H10K50/131—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit with spacer layers between the electroluminescent layers
    • 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]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • H10K50/13—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit
    • 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]
    • H10K50/14—Carrier transporting layers
    • H10K50/15—Hole transporting layers
    • 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
    • H10K59/30—Devices specially adapted for multicolour light emission
    • H10K59/32—Stacked devices having two or more layers, each emitting at different wavelengths
    • 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
    • H10K59/30—Devices specially adapted for multicolour light emission
    • H10K59/35—Devices specially adapted for multicolour light emission comprising red-green-blue [RGB] subpixels

Definitions

  • the present disclosure belongs to the field of display technology, and particularly relates to a light-emitting device and a display panel.
  • Tandem organic light-emitting diodes emerged as a result of the development of organic light-emitting diodes (OLEDs). Tandem OLEDs offer the advantages of high efficiency and brightness. However, related tandem OLED technologies suffer from inconsistent performance, such as light output efficiency and lifespan, among different color emitting devices.
  • the present disclosure aims to solve at least one of the technical problems existing in the prior art and provide a light emitting device and a display panel.
  • the technical solution adopted to solve the technical problem of the present disclosure is a light-emitting device, which includes an anode, a cathode, a plurality of light-emitting units arranged between the anode and the cathode, and a charge generating unit arranged between adjacent light-emitting units;
  • the plurality of light-emitting units include at least a first light-emitting unit and a second light-emitting unit, and the first light-emitting unit is closer to the anode than the second light-emitting unit;
  • the first light-emitting unit includes a first light-emitting layer, and a first hole transport subunit arranged on a side of the first light-emitting layer close to the anode;
  • the second light-emitting unit includes a second light-emitting layer, and a second hole transport subunit arranged on a side of the second light-emitting layer close to the anode; and the thickness of the first hole transport subunit of
  • the charge generation unit includes an N-type doped charge generation layer and a P-type doped charge generation layer arranged in sequence along a direction away from the anode; the surface of the N-type doped charge generation layer in contact with the P-type doped charge generation layer is a first surface; the surface of the first light-emitting layer close to the N-type doped charge generation layer is a second surface, and the distance from the first surface to the second surface is a first distance; the ratio of the thickness of the first hole transport subunit to the first distance is between 4 and 10.
  • the first distance is between 15 nm and 30 nm.
  • the first light-emitting unit further includes a first hole blocking layer disposed near the cathode in the first light-emitting layer; the thickness of the first hole blocking layer is between 5 nm and 10 nm.
  • the first hole transport subunit includes at least a first hole transport layer; the second hole transport subunit includes at least a second hole transport layer; the materials of the first hole transport layer and the second hole transport layer have the following general structural formula (I):
  • Ar1 to Ar3 are each independently selected from any one of hydrogen, deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boron, amino, arylphosphino, phosphine oxide, aryl, and heteroaryl; or, any adjacent groups among Ar1 to Ar3 are combined to form a ring; N represents a nitrogen atom.
  • the first hole transport subunit includes at least a first hole transport layer; the second hole transport subunit includes at least a second hole transport layer; the structural formula (II) of the material of the first hole transport layer and the material of the second hole transport layer is as follows:
  • Ar4 ⁇ Ar7 are each independently selected from any one of hydrogen, deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boron, amino, arylphosphino, phosphine oxide, aryl, and heteroaryl; or, any adjacent groups among Ar4 ⁇ Ar7 are combined to form a ring; L represents a substituted or unsubstituted arylene or heteroarylene group.
  • Ar1 to Ar3 are selected from any of the following structures:
  • * represents the position of connecting the general structural formula (1) or the position of the general structural formula (2).
  • Ar4 to Ar7 are selected from any of the following structures:
  • * represents the position of connecting the general structural formula (1) or the position of the general structural formula (2).
  • L is selected from any of the following structures:
  • the first hole transport subunit includes a first hole injection layer, a first hole transport layer, and a first electron blocking layer arranged in sequence along a direction away from the anode;
  • the second hole transport subunit includes a second hole transport layer and a second electron blocking layer arranged in sequence along a direction away from the anode.
  • an embodiment of the present disclosure further provides a display panel, which includes a plurality of light-emitting devices of different colors, wherein the plurality of light-emitting devices of different colors include a red light-emitting device, a green light-emitting device and a blue light-emitting device; each light-emitting device includes an anode, a cathode, a plurality of light-emitting units arranged between the anode and the cathode, and a charge generating unit arranged between adjacent light-emitting units; the plurality of light-emitting units include at least a first light-emitting unit and a second light-emitting unit, and the first light-emitting unit is closer to the anode than the second light-emitting unit; the first light-emitting unit includes a first light-emitting layer and a first hole transport subunit arranged on a side of the first light-emitting layer close to the anode; the second light
  • the charge generation unit includes an N-type doped charge generation layer and a P-type doped charge generation layer arranged in sequence along a direction away from the anode; the surface of the N-type doped charge generation layer in contact with the P-type doped charge generation layer is a first surface; the surface of the first light-emitting layer close to the N-type doped charge generation layer is a second surface, and the distance from the first surface to the second surface is a first distance; for the red light-emitting device, the ratio of the thickness of the first hole transport subunit to the first distance is between 6 and 10; for the green light-emitting device, the ratio of the thickness of the first hole transport subunit to the first distance is between 5 and 8; for the blue light-emitting device, the ratio of the thickness of the first hole transport subunit to the first distance is between 4 and 6.
  • the thickness of the first hole transport subunit of the red light-emitting device is greater than the thickness of the first hole transport subunit of the green light-emitting device; and the thickness of the first hole transport subunit of the green light-emitting device is greater than the thickness of the first hole transport subunit of the blue light-emitting device.
  • the thickness of the first hole transport subunit is between 170nm and 230nm; for the green light-emitting device, the thickness of the first hole transport subunit is between 130nm and 170nm; for the blue light-emitting device, the thickness of the first hole transport subunit is between 90nm and 130nm.
  • the first distance is between 15 nm and 30 nm.
  • the charge generating unit includes an N-type doped charge generating layer and a P-type doped charge generating layer arranged in sequence along a direction away from the anode; the surface of the N-type doped charge generating layer in contact with the P-type doped charge generating layer is a first surface; the surface of the second light-emitting layer close to the N-type doped charge generating layer is a third surface, and the distance from the third surface to the first surface closest to it is a second distance; the surface of the second light-emitting layer close to the cathode side is a fourth surface, and the shortest distance from the fourth surface to the cathode is a third distance; for the red light-emitting device, the ratio of the second distance to the third distance is between 2 and 3.2; for the green light-emitting device, the ratio of the second distance to the third distance is between 1.8 and 2.8; for the blue light-emitting device, the ratio of the second distance to the third distance is between 1.6 and
  • the second distance is between 80 nm and 110 nm; for the green light-emitting device, the second distance is between 65 nm and 95 nm; for the blue light-emitting device, the second distance is between 55 nm and 85 nm.
  • the thickness of the second hole transport subunit is between 70nm and 90nm; for the green light-emitting device, the thickness of the second hole transport subunit is between 60nm and 80nm; for the blue light-emitting device, the thickness of the second hole transport subunit is between 50nm and 70nm.
  • the first hole transport subunit includes a first hole injection layer, a first hole transport layer, and a first electron blocking layer arranged in sequence along a direction away from the anode; and the second hole transport subunit includes a second hole transport layer and a second electron blocking layer arranged in sequence along a direction away from the anode.
  • the thickness of the first hole injection layer of the plurality of light-emitting devices is the same, and the first hole injection layer of the plurality of light-emitting devices has an integrated structure; and the thickness of the first hole transport layer of the plurality of light-emitting devices is the same, and the first hole transport layer of the plurality of light-emitting devices has an integrated structure.
  • the thickness of the first electron blocking layer of the red light-emitting device is greater than the thickness of the first electron blocking layer of the green light-emitting device; and the thickness of the first electron blocking layer of the green light-emitting device is greater than the thickness of the first electron blocking layer of the blue light-emitting device.
  • the thickness of the second electron blocking layer of the red light-emitting device is greater than the thickness of the second electron blocking layer of the green light-emitting device; and the thickness of the second electron blocking layer of the green light-emitting device is greater than the thickness of the second electron blocking layer of the blue light-emitting device.
  • the materials of the first electron blocking layers corresponding to the red light-emitting device, the green light-emitting device, and the blue light-emitting device are different; the materials of the second electron blocking layers corresponding to the red light-emitting device, the green light-emitting device, and the blue light-emitting device are different; and the materials of the first light-emitting layers corresponding to the red light-emitting device, the green light-emitting device, and the blue light-emitting device are different; the materials of the second light-emitting layers corresponding to the red light-emitting device, the green light-emitting device, and the blue light-emitting device are different.
  • FIG1 is a schematic structural diagram of a light-emitting device provided in an embodiment of the present disclosure.
  • FIG2 is a schematic diagram of a subunit of a light-emitting unit provided in an embodiment of the present disclosure
  • FIG3 is a schematic diagram of a specific structure of a carrier transport subunit provided by an embodiment of the present disclosure
  • FIG4 is a schematic diagram of the film layer spacing in the light emitting device provided by an embodiment of the present disclosure.
  • FIG5 is a schematic diagram of the specific structure of another carrier transport subunit provided by an embodiment of the present disclosure.
  • FIG6 is a schematic diagram of a display panel provided in an embodiment of the present disclosure.
  • the carrier transport path in the Tandem device includes: in the first light-emitting unit, holes are transported from the anode to the first light-emitting layer; electrons are transported from the interface between the N-CGL layer (N-type doped charge generation layer) and the P-CGL layer (P-type doped charge generation layer) to the first light-emitting layer.
  • the second light-emitting unit holes are transported from the interface between the N-CGL layer and the P-CGL layer to the second light-emitting layer; electrons are transported from the cathode to the second light-emitting layer.
  • a hole blocking layer is often provided between the N-CGL layer and the first light-emitting layer.
  • the hole blocking layer is a combination of one or more organic layers and is mainly used to transport electrons and block holes.
  • the hole blocking layer when the hole blocking layer is in direct contact with the N-CGL layer, it is also used to block the metal ions doped in the N-CGL layer to prevent the migration of metal ions. Therefore, there is a large energy level barrier between the hole blocking layer and the N-CGL layer, resulting in a low electron transfer rate.
  • currently used hole transport materials offer faster hole transport speeds and higher hole injection efficiency.
  • embodiments of the present disclosure provide a light emitting device that substantially eliminates one or more problems due to limitations and disadvantages of the related art.
  • FIG1 is a schematic structural diagram of a light-emitting device provided in an embodiment of the present disclosure.
  • the light-emitting device includes an anode 1, a cathode 2, a plurality of light-emitting units disposed between the anode 1 and the cathode 2, and a charge generating unit 4 disposed between adjacent light-emitting units.
  • the plurality of light-emitting units include at least one first light-emitting unit 31 and one second light-emitting unit 32, and the first light-emitting unit 31 is closer to the anode 1 than the second light-emitting unit 32. That is, the light-emitting device of the present disclosure is a Tandem OLED device, which has the advantages of high efficiency and high brightness.
  • Figure 2 is a schematic diagram of the subunits of a light-emitting unit provided in an embodiment of the present disclosure.
  • the first light-emitting unit 31 includes a first light-emitting layer EML1 and a first hole transport subunit 311 disposed on the side of the first light-emitting layer EML1 near the anode 1;
  • the second light-emitting unit 32 includes a second light-emitting layer EML2 and a second hole transport subunit 321 disposed on the side of the second light-emitting layer EML2 near the anode 1.
  • the first hole transport subunit 311 is primarily used to transport holes generated by the anode 1 or the charge generation unit 4, thereby improving hole transport efficiency.
  • the second hole transport subunit 321 is primarily used to transport holes generated by the charge generation unit 4, thereby improving hole transport efficiency.
  • the first light-emitting unit 31 further includes a first electron transport subunit 312 disposed on the side of the first light-emitting layer EML1 close to the cathode 2;
  • the second light-emitting unit 32 further includes a second electron transport subunit 322 disposed on the side of the second light-emitting layer EML2 close to the cathode 2.
  • the first electron transport subunit 312 is primarily used to transport electrons generated by the charge generation unit 4, thereby improving electron transport efficiency;
  • the second electron transport subunit 322 is primarily used to transport electrons generated by the cathode 2, thereby improving electron transport efficiency.
  • the plurality of light-emitting units includes a first light-emitting unit 31 and a second light-emitting unit 32. Further exemplary, the plurality of light-emitting units includes a plurality of first light-emitting units 31 and a second light-emitting unit 32.
  • the thickness of the first hole transport subunit 311 of at least some of the first light-emitting units 31 in the plurality of first light-emitting units 31 is greater than the thickness of the second hole transport subunit 321 of the second light-emitting unit 32.
  • a light-emitting device comprising a first light-emitting unit 31, a charge generation unit 4, and a second light-emitting unit 32 is used as an example.
  • the anode 1 in the light-emitting device generates holes
  • the cathode 2 generates electrons.
  • the charge generation unit 4 similarly forms holes and electrons, which then separate.
  • the holes generated by the anode 1 are transferred to the first light-emitting layer EML1 via the first hole transport subunit 311, while the electrons generated by the charge generation unit 4 are transferred to the first light-emitting layer EML1 via the first electron transport subunit 312.
  • the holes generated by the charge generation unit 4 are transferred to the second light-emitting layer EML2 via the second hole transport subunit 321, while the electrons generated by the cathode 2 are transferred to the second light-emitting layer EML2 via the second electron transport subunit 322.
  • the holes and electrons migrate to the first light-emitting layer EML1 (or second light-emitting layer EML2), where they recombine to generate excitons, which then emit light through radiative transition.
  • FIG3 is a schematic diagram of the specific structure of a carrier transport subunit provided in an embodiment of the present disclosure.
  • the first hole transport subunit 311 includes at least a first hole transport layer HTL1
  • the second hole transport subunit 321 includes at least a second hole transport layer HTL2
  • the first electron transport subunit 312 includes at least a first hole blocking layer HBL1
  • the second electron transport subunit 322 includes at least a second hole blocking layer HBL2.
  • the first hole blocking layer HBL1 is a combination of one or more organic layers, primarily used to transport electrons and block holes.
  • first hole blocking layer HBL1 when the first hole blocking layer HBL1 is in direct contact with the charge generation unit 4, it is also used to block the metal ions doped in the charge generation unit 4 to prevent the migration of the metal ions. Therefore, there is a large energy barrier between the first hole blocking layer HBL1 and the charge generation unit 4, resulting in a low electron transfer rate.
  • the thickness of the first hole transport subunit 311 of the first light-emitting unit 31 is greater than the thickness of the second hole transport subunit 321 of the second light-emitting unit 32.
  • the embodiment of the present disclosure adjusts the thickness of the first hole transport subunit 311 and/or the second hole transport subunit 321 of each color light-emitting device. For example, by increasing the thickness of the first hole transport subunit 311 of the first light-emitting unit 31, the thickness of the first hole transport subunit 311 is greater than the thickness of the second hole transport subunit 321. This increases the hole transport path from the anode 1 to the first light-emitting layer EML1, thereby increasing the hole transport time in the first hole transport subunit 311.
  • the charge generation unit 4 includes an N-type doped charge generation layer N-CGL and a P-type doped charge generation layer P-CGL, arranged sequentially in a direction away from the anode 1.
  • the surface of the N-type doped charge generation layer N-CGL in contact with the P-type doped charge generation layer P-CGL is a first surface.
  • the surface of the first light-emitting layer EML1 proximal to the N-type doped charge generation layer N-CGL is a second surface, and the distance from the first surface to the second surface is a first distance L1.
  • the first distance L1 can be understood as the transmission distance of the electrons generated by the charge generation unit 4, that is, the length of the electron transmission path from the generation starting point to the first light-emitting layer EML1.
  • the materials of the light-emitting layers of light-emitting devices of different colors are different, the materials of the sub-film layers in the first hole transport subunit 311 may be different, so the hole mobility corresponding to light-emitting devices of different colors and the energy level differences between the film layers are different.
  • a ratio of the thickness of the first hole transport subunit 311 to the first distance L1 is between 4 and 10.
  • FIG4 is a schematic diagram of the interlayer spacing in a light-emitting device provided in an embodiment of the present disclosure.
  • the ratio of the thickness R_H of the first hole transport subunit 311 to the first distance L1 is between 6 and 10.
  • the ratio of the thickness R_H of the first hole transport subunit 311 to the first distance L1 is between 6 and 10, thereby ensuring balanced carrier (hole and electron) transport within the red light-emitting device R.
  • the ratio of the thickness G_H of the first hole transport subunit 311 to the first distance L1 is between 5 and 8.
  • the ratio of the thickness G_H of the first hole transport subunit 311 to the first distance L1 is between 5 and 8, thereby ensuring balanced carrier (hole and electron) transmission within the green light-emitting device G.
  • the ratio of the thickness B_H of the first hole transport subunit 311 to the first distance L1 is between 4 and 6.
  • the ratio of the thickness B_H of the first hole transport subunit 311 to the first distance L1 is between 4 and 6, thereby ensuring balanced carrier (hole and electron) transmission within the blue light-emitting device B.
  • the thickness R_H of the first hole transport subunit of the red light-emitting device is greater than the thickness G_H of the first hole transport subunit of the green light-emitting device; and the thickness G_H of the first hole transport subunit of the green light-emitting device is greater than the thickness B_H of the first hole transport subunit of the blue light-emitting device.
  • the thickness R_H of the first hole transport subunit 311 is between 170 nm and 230 nm.
  • this embodiment reduces the hole transport rate by increasing the thickness R_H of the first hole transport subunit 311 of the red light-emitting device R, that is, the length of the hole transport path. This balances the transport rates of holes and electrons, allowing them to recombine within the first light-emitting layer REML1, thereby ensuring the luminous stability of the red light-emitting device R.
  • the thickness R_H of the first hole transport subunit 311 is 170 nm, 200 nm, or 230 nm.
  • the thickness G_H of the first hole transport subunit 311 is between 130 nm and 170 nm.
  • this embodiment increases the thickness G_H of the first hole transport subunit 311 of the green light-emitting device G, i.e., the length of the hole transport path, thereby reducing the hole transport rate. This balances the transport rates of holes and electrons, allowing them to recombine within the first light-emitting layer GEML1, thereby ensuring the luminous stability of the green light-emitting device G.
  • the thickness G_H of the first hole transport subunit 311 is 130 nm, 150 nm or 170 nm.
  • the thickness B_H of the first hole transport subunit 311 is between 90 nm and 130 nm.
  • this embodiment increases the thickness B_H of the first hole transport subunit 311 of the blue light-emitting device B, i.e., the length of the hole transport path, thereby reducing the hole transport rate. This balances the transport rates of holes and electrons, allowing them to recombine within the first light-emitting layer BEML1, thereby ensuring the luminous stability of the blue light-emitting device B.
  • the first hole transport subunit 311 includes at least one of a first hole injection layer HIL1 , a first hole transport layer HTL1 , and a first electron blocking layer EBL1 .
  • the first hole transport subunit 311 includes a first hole injection layer HIL1, a first hole transport layer HTL1, and a first electron blocking layer EBL1, arranged in sequence away from the anode 1.
  • the first hole injection layer HIL1 is primarily used to improve hole injection efficiency, thereby improving hole transport efficiency.
  • the first hole transport layer HTL1 is primarily used to transport holes generated by the anode 1 or the charge generation unit 4, thereby improving hole transport efficiency.
  • the first electron blocking layer EBL1 is primarily used to block electrons and transport holes.
  • the transport rates of holes and electrons can be balanced by increasing the thickness of the first electron blocking layer EBL1 of light-emitting devices of different colors. And/or the transport rates of holes and electrons can be balanced by increasing the thickness of the first hole transport layer HTL1 of light-emitting devices of different colors.
  • the first hole injection layer HIL1 corresponding to each of the red, green, and blue light-emitting devices R, G, and B has the same thickness, for example, 10 nm, and has a monolithic structure.
  • the first hole transport layer HTL1 corresponding to each of the red, green, and blue light-emitting devices R, G, and B has the same thickness, for example, 100 nm, and has a monolithic structure.
  • the first electron blocking layer EBL1 corresponding to each of the red, green, and blue light-emitting devices R, G, and B has different thicknesses.
  • the first electron blocking layer REBL1 corresponding to the red, green, and blue light-emitting devices R, G, and B has a greater thickness than the first electron blocking layer GEBL1 corresponding to the green light-emitting device G; and the first electron blocking layer GEBL1 corresponding to the green light-emitting device G has a greater thickness than the first electron blocking layer BEBL1 corresponding to the blue light-emitting device B.
  • the thickness of the first electron blocking layer REBL1 corresponding to the red light-emitting device R is 90 nm; the thickness of the first electron blocking layer GEBL1 corresponding to the green light-emitting device G is 40 nm; and the thickness of the first electron blocking layer BEBL1 corresponding to the blue light-emitting device B is 5 nm.
  • the contact interface between the N-type doped charge generation layer N-CGL and the P-type doped charge generation layer P-CGL is a first surface.
  • the distance from the first surface to the second surface of the first light-emitting layer EML1, which is closest to the N-type doped charge generation layer N-CGL, is denoted as a first distance L1.
  • the first distance L1 is between 15 nm and 30 nm.
  • This embodiment achieves a high-efficiency and stable tandem light-emitting device by adjusting the first distance L1, i.e., the length of the transmission path of the electrons generated by the charge generation unit 4, to balance the transmission rate of the holes generated by the anode 1 and the transmission rate of the electrons generated by the charge generation unit 4.
  • the first distance L1 can be adjusted by adjusting the thickness of the first electron transport subunit 312.
  • the first electron transport subunit 312 includes at least one first hole blocking layer HBL1.
  • the first hole blocking layer HBL1 is primarily used to block holes, block metal ions doped in the N-type doped charge generation layer N-CGL, and transport electrons.
  • the thickness of the first hole blocking layer HBL1 is between 5 nm and 10 nm.
  • this embodiment reduces the thickness of the first hole blocking layer HBL1, that is, shortens the length of the electron transmission path to increase the electron transmission rate, thereby balancing the transmission rates of holes and electrons, so that the two are combined in the first light-emitting layer EML1, and ensuring the luminous stability of the red light-emitting device R.
  • FIG5 is a schematic diagram of the specific structure of another carrier transport subunit provided in an embodiment of the present disclosure.
  • the first electron transport subunit 312 includes a first hole blocking layer HBL1 and a first electron transport layer ETL1.
  • the first hole blocking layer HBL1 is closer to the first light-emitting layer EML1 than the first electron transport layer ETL1.
  • the first electron transport layer ETL1 is primarily used to transport electrons generated by the charge generation unit 4, thereby improving electron transport efficiency.
  • the thickness of the first hole-blocking layer HBL1 is between 5 nm and 10 nm.
  • the thickness of the first electron-transporting layer ETL1 is between 5 nm and 30 nm.
  • the charge generation unit 4 includes an N-type doped charge generation layer N-CGL and a P-type doped charge generation layer P-CGL, arranged sequentially in a direction away from the anode 1.
  • the surface of the N-type doped charge generation layer N-CGL in contact with the P-type doped charge generation layer P-CGL is a first surface.
  • the surface of the second light-emitting layer EML2 proximal to the N-type doped charge generation layer N-CGL is a third surface, and the distance from the third surface to the first surface closest thereto is a second distance L2.
  • the second distance L2 can be understood as the transmission distance of the holes generated by the charge generation unit 4, that is, the length of the hole transmission path from the hole generation point to the second light-emitting layer EML2.
  • the distance from the surface of the first light-emitting unit 31 close to the N-type doped charge generating layer N-CGL to the first surface also represents the length of the hole transmission path from the hole generation starting point to the first light-emitting layer EML1.
  • first light emitting unit 31 and one second light emitting unit 32 are described by taking one first light emitting unit 31 and one second light emitting unit 32 as an example, and does not elaborate on the case of multiple first light emitting units 31 .
  • the surface of the second light-emitting layer EML2 close to the cathode 2 is the fourth surface, and the shortest distance from the fourth surface to the cathode 2 is the third distance L3.
  • the third distance L3 can be understood as the transmission distance of the electrons generated by the cathode 2, that is, the length of the electron transmission path from the generation starting point to the second light-emitting layer EML2.
  • the materials of the light-emitting layers of light-emitting devices of different colors are different, the materials of the sub-film layers in the first hole transport subunit 311 may be different, so the hole mobility corresponding to light-emitting devices of different colors and the energy level differences between the film layers are different.
  • the ratio of the second distance R_L2 to the third distance L3 is between 2 and 3.2.
  • This embodiment adjusts the second distance R_L2 of the hole transmission path and the third distance L3 of the electron transmission path in the second light-emitting unit 32 corresponding to the red light-emitting device R so that the ratio of the second distance R_L2 to the third distance L3 is between 2 and 3.2, thereby ensuring balanced carrier (hole and electron) transmission within the red light-emitting device R.
  • the ratio of the second distance G_L2 to the third distance L3 is between 1.8 and 2.8.
  • the ratio of the second distance G_L2 to the third distance L3 is between 1.8 and 2.8, thereby ensuring balanced carrier (hole and electron) transmission within the green light-emitting device G.
  • the ratio of the second distance B_L2 to the third distance L3 is between 1.6 and 2.6.
  • the second distance B_L2 of the hole transmission path and the third distance L3 of the electron transmission path in the second light-emitting unit 32 are adjusted so that the ratio of the second distance B_L2 to the third distance L3 is between 1.6 and 2.6, thereby ensuring balanced carrier (hole and electron) transmission within the blue light-emitting device B.
  • the second distance R_L2 is between 80 nm and 110 nm.
  • this embodiment increases the second distance R_L2 of the red light-emitting device R, i.e., the length of the hole transmission path, to reduce the hole transmission rate, thereby balancing the transmission rates of holes and electrons, allowing them to recombine within the second light-emitting layer REML2, thereby ensuring the luminous stability of the red light-emitting device R.
  • the second distance R_L2 is 85 nm, 95 nm or 110 nm.
  • the second distance G_L2 is between 65 nm and 95 nm.
  • this embodiment increases the second distance G_L2 of the green light-emitting device G, i.e., the length of the hole transport path, to reduce the hole transport rate, thereby balancing the transport rates of holes and electrons, allowing them to recombine within the second light-emitting layer GEML2, thereby ensuring the luminous stability of the green light-emitting device G.
  • the second distance G_L2 is 65 nm, 85 nm or 95 nm.
  • the second distance B_L2 is between 55 nm and 85 nm.
  • this embodiment increases the second distance B_L2 of the blue light-emitting device B, i.e., the length of the hole transport path, to reduce the hole transport rate. This balances the transport rates of holes and electrons, allowing them to recombine within the second light-emitting layer BEML2, thereby ensuring the luminous stability of the blue light-emitting device B.
  • the second distance B_L2 is 55 nm, 70 nm or 85 nm.
  • the method of increasing the second distance R_L2 of the red light-emitting device R specifically includes: the thickness of the second hole transport subunit 321 can be set between 70nm and 90nm, and the second distance R_L2 of the red light-emitting device R is increased by increasing the thickness of the second hole transport subunit 321.
  • the method of increasing the second distance G_L2 of the green light-emitting device G specifically includes: the thickness of the second hole transport subunit 321 can be set between 60nm and 80nm, and the second distance G_L2 of the green light-emitting device G can be increased by increasing the thickness of the second hole transport subunit 321.
  • the method of increasing the second distance B_L2 of the blue light-emitting device B specifically includes: the thickness of the second hole transport subunit 321 can be set between 50nm and 70nm, and the second distance B_L2 of the blue light-emitting device B can be increased by increasing the thickness of the second hole transport subunit 321.
  • the second hole transport subunit 321 includes at least one of a second hole transport layer HTL2 and a second electron blocking layer EBL2.
  • the second hole transport subunit 321 includes a second hole transport layer HTL2 and a second electron blocking layer EBL2, which are sequentially arranged in a direction away from the anode 1.
  • the second hole transport layer HTL2 is primarily used to transport holes generated by the charge generation unit 4 to improve hole transport efficiency.
  • the second electron blocking layer EBL2 is primarily used to block electrons and transport holes.
  • the second hole transport subunit 321 includes a second hole injection layer HIL2, a second hole transport layer HTL2, and a second electron blocking layer EBL2, which are sequentially arranged in a direction away from the anode 1.
  • the transport rates of holes and electrons can be balanced by increasing the thickness of the second electron blocking layer EBL2 of light-emitting devices of different colors. And/or, the transport rates of holes and electrons can be balanced by increasing the thickness of the second hole transport layer HTL2 of light-emitting devices of different colors.
  • the thickness of the second hole transport layer HTL2 corresponding to each of the red light-emitting device R, the green light-emitting device G, and the blue light-emitting device B can be the same, for example, 55 nm.
  • the thickness of the second electron blocking layer EBL2 corresponding to each of the red light-emitting device R, the green light-emitting device G, and the blue light-emitting device B can be different.
  • the thickness of the second electron blocking layer EBL2 corresponding to the red light-emitting device R is greater than the thickness of the second electron blocking layer EBL2 corresponding to the green light-emitting device G; and the thickness of the second electron blocking layer EBL2 corresponding to the green light-emitting device G is greater than the thickness of the second electron blocking layer EBL2 corresponding to the blue light-emitting device B.
  • the thickness of the second electron blocking layer EBL2 corresponding to the red light-emitting device R is 30 nm; the thickness of the second electron blocking layer EBL2 corresponding to the green light-emitting device G is 20 nm; and the thickness of the second electron blocking layer EBL2 corresponding to the blue light-emitting device B is 5 nm.
  • the surface of the second light-emitting layer EML2 on the side closest to the cathode 2 is a fourth surface, and the shortest distance from the fourth surface to the cathode 2 is a third distance L3.
  • the third distance L3 is between 30 nm and 50 nm. This embodiment achieves a highly efficient and stable tandem light-emitting device by adjusting the third distance L3, i.e., the length of the transmission path of the electrons generated by the cathode 2, to balance the transmission rate of the holes generated by the charge generation unit 4 and the transmission rate of the electrons generated by the cathode 2.
  • the second light-emitting unit 32 further includes a second electron transport subunit 322 disposed on a side of the second light-emitting layer EML2 close to the cathode 2.
  • the thickness of the second electron transport subunit 322 is the third distance L3.
  • the second electron transport subunit 322 includes an electron injection layer EIL, an electron transport layer ETL, and a second hole blocking layer HBL2, which are sequentially disposed in a direction away from the cathode 2.
  • the electron injection layer EIL is primarily used to improve electron injection efficiency, thereby improving electron transport efficiency.
  • the electron transport layer ETL is primarily used to transport electrons generated by the cathode 2 to improve electron transport efficiency.
  • the second hole blocking layer HBL2 is primarily used to block hole electrons and transport electrons.
  • the second light-emitting unit 32 further includes a second electron transport subunit 322 disposed on a side of the second light-emitting layer EML2 close to the cathode 2.
  • the second electron transport subunit 322 includes an electron injection layer EIL, a second electron transport layer ETL2, and a second hole blocking layer HBL2, which are sequentially disposed in a direction away from the cathode 2.
  • the present disclosure can also adjust the hole transport material to select a hole transport material that can balance the hole and electron transport efficiency.
  • the first hole transport subunit 311 includes at least a first hole transport layer HTL1; the second hole transport subunit 321 includes at least a second hole transport layer HTL2; the structural formula (1) of the material of the first hole transport layer HTL1 and the material of the second hole transport layer HTL2 is as follows:
  • Ar1 to Ar3 are each independently selected from any one of hydrogen, deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boron, amino, arylphosphino, phosphine oxide, aryl, and heteroaryl; or, any adjacent groups among Ar1 to Ar3 are combined to form a ring; N represents a nitrogen atom.
  • the first hole transport subunit 311 includes at least a first hole transport layer HTL1; the second hole transport subunit 321 includes at least a second hole transport layer HTL2; the structural formula (II) of the material of the first hole transport layer HTL1 and the material of the second hole transport layer HTL2 is as follows:
  • Ar4 ⁇ Ar7 are each independently selected from any one of hydrogen, deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boron, amino, arylphosphino, phosphine oxide, aryl, and heteroaryl; or, any adjacent groups among Ar4 ⁇ Ar7 are combined to form a ring; L represents a substituted or unsubstituted arylene or heteroarylene group.
  • Ar1 to Ar7 are selected from any of the following structures:
  • * represents the position of connecting the general structural formula (1) or the position of the general structural formula (2).
  • the materials of the first hole transport layer HTL1 and the second hole transport layer HTL2 are selected to adapt the electron transport efficiency to match the electron injection and transport rates, thereby realizing a highly efficient and stable tandem OLED device.
  • L is selected from any of the following structures:
  • the cathode 2 and the anode 1 each independently include at least one selected from silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), lithium fluoride/calcium (LiF/Ca), lithium fluoride/aluminum (LiF/Al), molybdenum (Mo), titanate (Ti), indium (In), tin (Sn), zinc (Zn), and ytterbium (Yb), or oxides thereof.
  • the anode 1 when the light-emitting device is a top-emitting device, the anode 1 is a reflective electrode, and the cathode 2 is a transmissive or semi-transmissive electrode.
  • the anode 1 is selected from a material with a high work function, such as an ITO/Ag/ITO laminate structure; the cathode 2 is selected from a material with a low work function, and can be a semi-transmissive metal or metal alloy material, such as an Ag/Mg alloy material.
  • the material of the hole injection layer may include, but is not limited to, a p-type dopant and a hole transport material of a strong electron-withdrawing system doped together.
  • the p-type dopant may include any one or more combinations of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyano-p-benzoquinone (F4TCNQ), and 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane.
  • the hole transport material may include any one or more combinations of aromatic amine hole transport materials, dimethylfluorene hole transport materials, and carbazole hole transport materials.
  • the hole transport material may include any one or more combinations of 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (TPD), 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (BAFLP), 4,4′-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4′-di(9-carbazolyl)biphenyl (CBP) and 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (PCzPA).
  • NPB 4,4′-bis[N-(1-n
  • the material of the electron blocking layer may include, but is not limited to, any one or more combinations of aromatic amine electron blocking materials, dimethylfluorene electron blocking materials, and carbazole electron blocking materials.
  • the material of the electron blocking layer may include any one or more combinations of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-di(9-carbazolyl)biphenyl (CBP) and 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (PCzPA).
  • NPB 4,4'-bis[N-(
  • the material of the light-emitting layer may include one light-emitting material, or may include two or more light-emitting materials.
  • the material of the light-emitting layer may include a host light-emitting material and a guest light-emitting material doped into the host light-emitting material; the material of the light-emitting layer may include a light-emitting material having thermally activated delayed fluorescence at room temperature, a light-emitting material having fluorescence at room temperature, or a light-emitting material having phosphorescence at room temperature.
  • the material of the first light-emitting layer EML1 is a red light-emitting material, which may specifically include any one or more combinations of DCM-type red light-emitting materials and metal complex-type red light-emitting materials.
  • the red light-emitting material may include any one or more combinations of 4-(dicyanomethylidene)-2-methyl-6-(4-dimethylaminophenyl)-4H-pyran (DCM), 4-(dicyanomethylidene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidine-9-enyl)-4H-pyran (DCJTB), bis(1-phenylisoquinolinol)(acetylacetonato)iridium(III) (Ir(piq)2(acac)), octaethylporphyrin platinum (abbreviated as PtOEP), and bis(2-(2'-benzothienyl)pyridine-N,C3')(acetylacetonato)iridium (abbreviated as Ir(btp)2(acac).
  • DCM 4-(dicyanomethylidene)-2-methyl-6
  • the material of the first light-emitting layer EML1 is a green light-emitting material, which can specifically include any one or more combinations of coumarin dyes, quinacridone copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, and metal complexes. Green light-emitting materials.
  • the green light-emitting material may include coumarin 6 (C-6), coumarin 545T (C-525T), quinacridone copper (QA), N,N’-dimethylquinacridone (DMQA), 5,12-diphenylnaphthonaphthalene (DPT), N10,N10’-diphenyl-N10,N10’-diphthaloyl-9,9’-dianthracene-10,10’-diamine (abbreviated as: BA-NPB), tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq3), tris(2-phenylpyridine)iridium (Ir(ppy)3), and di(2-phenylpyridine)iridium acetylacetonate (Ir(ppy)2(acac)).
  • C-6 coumarin 6
  • C-525T quinacridone copper
  • DMQA N,N’-dimethylquinacridone
  • DPT 5,12
  • the material of the first light-emitting layer EML1 is a blue light-emitting material, which can specifically include any one or more combinations of pyrene derivative blue light-emitting materials, anthracene derivative blue light-emitting materials, fluorene derivative blue light-emitting materials, perylene derivative blue light-emitting materials, styrylamine derivative blue light-emitting materials and metal complex blue light-emitting materials.
  • the blue light-emitting material may include any one or more combinations of N1,N6-di([1,1’-biphenyl]-2-yl)-N1,N6-di([1,1’-biphenyl]-4-yl)pyrene-1,6-diamine, 9,10-di-(2-naphthyl)anthracene (ADN), 2-methyl-9,10-di-2-naphthylanthracene (MADN), 2,5,8,11-tetra-tert-butylperylene (TBPe), 4,4’-bis[4-(diphenylamino)phenylvinyl]biphenyl (BDAVBi), 4,4’-bis[4-(di-p-tolylamino)phenylvinyl]biphenyl (DPAVBi), and bis(4,6-difluorophenylpyridine-C2,N)picolinyliridium (FIr)
  • the material of the hole blocking layer may include, but is not limited to, aromatic heterocyclic hole blocking materials.
  • the material of the hole blocking layer may include any one or more combinations of benzimidazole and its derivatives hole blocking materials, imidazopyridine and its derivatives hole blocking materials, benzimidazolephenanthridine derivatives hole blocking materials, pyrimidine and its derivatives hole blocking materials, triazine derivatives hole blocking materials, pyridine and its derivatives hole blocking materials, pyrazine and its derivatives hole blocking materials, quinoxaline and its derivatives hole blocking materials, diazole and its derivatives hole blocking materials, quinoline and its derivatives hole blocking materials, isoquinoline derivatives hole blocking materials, phenanthroline derivatives hole blocking materials, diazaphosphotadiene hole blocking materials, phosphine oxide hole blocking
  • the material of the hole blocking layer may include any one or more combinations of 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (p-EtTAZ), bathophenanthroline (BPhen), (BCP), and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (BzOs).
  • PBD 2-(4-biphenyl)-5-(4-
  • the material of the electron transport layer ETL includes, but is not limited to, imidazole derivatives such as benzimidazole derivatives, imidazopyridine derivatives, and benzimidazolephenanthridine derivatives; oxazine derivatives such as pyrimidine derivatives and triazine derivatives; quinoline derivatives, isoquinoline derivatives, phenanthroline derivatives, and other compounds containing a nitrogen-containing six-membered ring structure (also including compounds having a phosphine oxide-based substituent on the heterocyclic ring, such as OXD-7, TAZ, p-EtTAZ), BPhen, BCP, etc.
  • imidazole derivatives such as benzimidazole derivatives, imidazopyridine derivatives, and benzimidazolephenanthridine derivatives
  • oxazine derivatives such as pyrimidine derivatives and triazine derivatives
  • quinoline derivatives isoquinoline derivatives, phen
  • the material of the electron injection layer includes, but is not limited to, a compound of one or more combinations of Li, Yb, Mg, and Ca.
  • the hole injection layer (e.g., the first hole injection layer HIL1 and the second hole injection layer HIL2) and the P-type doped charge generation layer P-CGL each include a hole injection material HIL' and a hole transport material HTL' doped together, wherein the molecular structure of the hole injection material HIL' is:
  • the molecular structure of the hole transport material HTL' is:
  • the material molecular structure of the electron blocking layer (the first electron blocking layer REBL1 and the second electron blocking layer REBL2) corresponding to the red light-emitting device R is:
  • the material molecular structure of the electron blocking layer (the first electron blocking layer GEBL1 and the second electron blocking layer GEBL2) corresponding to the green light-emitting device G is:
  • the material molecular structure of the electron blocking layer (first electron blocking layer BEBL1 and second electron blocking layer BEBL2) corresponding to the blue light-emitting device B is:
  • the materials of the light-emitting layers (the first light-emitting layer REML1 and the second light-emitting layer REML2) corresponding to the red light-emitting device R include a host material (RH) and a guest material (RD), wherein the host material (RH) includes a P-type doped host material (RH_P) and an N-type doped host material (RH_N).
  • the molecular structure of the P-type doped host material (RH_P) is:
  • the molecular structure of the N-type doped host material (RH_N) is:
  • the molecular structure of the guest material (RD) is the same as the guest material (RD).
  • the doping mass ratio of the P-type doped host material (RH_P) to the N-type doped host material (RH_N) is 1:1.
  • the materials of the light-emitting layers (the first light-emitting layer GEML1 and the second light-emitting layer GEML2) corresponding to the green light-emitting device G include a host material (GH) and a guest material (GD), wherein the host material (GH) includes a P-type doped host material (GH_P) and an N-type doped host material (GH_N).
  • the molecular structure of the P-type doped host material (GH_P) is:
  • the molecular structure of N-type doped host material is:
  • the molecular structure of the guest material (GD) is:
  • the doping mass ratio of the P-type doped main material (GH_P) to the N-type doped main material (GH_N) is 1:1.
  • the materials of the light-emitting layers (first light-emitting layer BEML1 and second light-emitting layer BEML2) corresponding to the blue light-emitting device B include a host material (BH) and a guest material (BD).
  • the molecular structure of the host material (BH) is:
  • the molecular structure of the guest material (BD) is:
  • the molecular structure of the material of the N-type doped charge generation layer N-CGL is:
  • the molecular structure of the material of the hole blocking layer (eg, the first hole blocking layer HBL1 and the second hole blocking layer HBL2) is:
  • the material of the electron transport layer ETL (or the first electron transport layer ETL1 and the second electron transport layer ETL2) includes an electron transport material ETL' and Liq doped together.
  • the molecular structure of the electron transport material ETL' is:
  • the electron transport material ETL' and Liq doped together in the electron transport layer ETL have a doping mass ratio of 1:1.
  • the present disclosure uses the intercalation method to randomly screen and verify the light-emitting devices in certain embodiments, proving that the present disclosure can effectively balance the carrier transmission rate by increasing the thickness of the first hole transport subunit 311 and/or the second hole transport subunit 321, thereby ensuring the high efficiency and stability of the series light-emitting devices.
  • a verification light-emitting layer (ELL) with a different color than the first light-emitting layer (EML1) is inserted into a specific light-emitting device. If the verification light-emitting layer emits light, it indicates that the carrier recombination center has shifted away from the first light-emitting layer (EML1), and recombination has occurred there, affecting the luminous efficiency and lifespan of the light-emitting device. If the verification light-emitting layer does not emit light, it indicates that the carrier recombination center has not shifted away from the first light-emitting layer (EML1), and recombination has occurred there, which does not affect the luminous efficiency of the light-emitting device.
  • Comparative Example 1 Device structure of red light-emitting device R, ITO ⁇ HTL’:HIL’,97:3,10nm ⁇ HTL1,20nm ⁇ REBL1,35nm ⁇ REML1(RH:RD,5%),40nm ⁇ verification light-emitting layer EML1(GH:GD,10%),3nm ⁇ HBL1,5nm ⁇ N-CGL(CGL:Li,1%),20nm ⁇ P-CGL(HTL’:HIL’,90:10),10nm ⁇ HTL2,35nm ⁇ REBL2,35nm ⁇ REML2(RH:RD,5%),40nm ⁇ verification light-emitting layer EML2(GH:GD,10%),3nm ⁇ HBL2,5nm ⁇ ETL’:Liq,1:1,30nm ⁇ Yb,1nm ⁇ Mg:Ag,13nm ⁇ CPL,60nm.
  • Example 1 Device structure of red light-emitting device R, ITO ⁇ HTL’:HIL’,97:3,10nm ⁇ HTL1,100nm ⁇ REBL1,90nm ⁇ REML1(RH:RD,5%),40nm ⁇ verification light-emitting layer EML1(GH:GD,10%),3nm ⁇ HBL1,5nm ⁇ N-CGL(CGL:Li,1%),20nm ⁇ P-CGL(HTL’:HIL’,90:10),10nm ⁇ HTL2,55nm ⁇ REBL2,30nm ⁇ REML2(RH:RD,5%),40nm ⁇ verification light-emitting layer EML2(GH:GD,10%),3nm ⁇ HBL2,5nm ⁇ ETL’:Liq,1:1,30nm ⁇ Yb,1nm ⁇ Mg:Ag,13nm ⁇ CPL,60nm.
  • Comparative Example 2 Device structure of green light-emitting device G, ITO ⁇ HTL’:HIL’,97:3,10nm ⁇ HTL1,20nm ⁇ GEBL1,15nm ⁇ GEML1(GH:GD,10%),30nm ⁇ verification light-emitting layer EML1(RH:RD,10%),3nm ⁇ HBL1,5nm ⁇ N-CGL(CGL:Li,1%),20nm ⁇ P-CGL(HTL’:HIL’,90:10),10nm ⁇ HTL2,35nm ⁇ GEBL2,15nm ⁇ GEML2(GH:GD,10%),30nm ⁇ verification light-emitting layer EML2(RH:RD,10%),3nm ⁇ HBL2,5nm ⁇ ETL’:Liq,1:1,30nm ⁇ Yb,1nm ⁇ Mg:Ag,13nm ⁇ CPL,60nm.
  • Example 2 Device structure of green light-emitting device G, ITO ⁇ HTL’:HIL’,97:3,10nm ⁇ HTL1,100nm ⁇ GEBL1,40nm ⁇ GEML1(GH:GD,10%),30nm ⁇ verification light-emitting layer EML1(RH:RD,10%),3nm ⁇ HBL1,5nm ⁇ N-CGL(CGL:Li,1%),20nm ⁇ P-CGL(HTL’:HIL’,90:10),10nm ⁇ HTL2,55nm ⁇ GEBL2,20nm ⁇ GEML2(GH:GD,10%),30nm ⁇ verification light-emitting layer EML2(RH:RD,10%),3nm ⁇ HBL2,5nm ⁇ ETL’:Liq,1:1,30nm ⁇ Yb,1nm ⁇ Mg:Ag,13nm ⁇ CPL,60nm.
  • Comparative Example 3 Device structure of blue light-emitting device B, ITO ⁇ HTL’:HIL’,97:3,10nm ⁇ HTL1,20nm ⁇ BEBL1,5nm ⁇ BEML1(BH:BD,2%),7nm ⁇ verification light-emitting layer EML1(RH:RD,10%),3nm ⁇ HBL1,5nm ⁇ N-CGL(CGL:Li,1%),20nm ⁇ P-CGL(HTL’:HIL’,90:10),10nm ⁇ HTL2,35nm ⁇ BEBL2,5nm ⁇ BEML2(BH:BD,2%),7nm ⁇ verification light-emitting layer EML2(RH:RD,10%),3nm ⁇ HBL2,5nm ⁇ ETL’:Liq,1:1,30nm ⁇ Yb,1nm ⁇ Mg:Ag,13nm ⁇ CPL,60nm.
  • Example 3 Device structure of blue light-emitting device B, ITO ⁇ HTL’:HIL’,97:3,10nm ⁇ HTL1,100nm ⁇ BEBL1,5nm ⁇ BEML1(BH:BD,2%),7nm ⁇ verification light-emitting layer EML1(RH:RD,10%),3nm ⁇ HBL1,5nm ⁇ N-CGL(CGL:Li,1%),20nm ⁇ P-CGL(HTL’:HIL’,90:10),10nm ⁇ HTL2,55nm ⁇ BEBL2,5nm ⁇ BEML2(BH:BD,2%),7nm ⁇ verification light-emitting layer EML2(RH:RD,10%),3nm ⁇ HBL2,5nm ⁇ ETL’:Liq,1:1,30nm ⁇ Yb,1nm ⁇ Mg:Ag,13nm ⁇ CPL,60nm.
  • “ ⁇ ” indicates the order from the anode to the cathode and then to the light extraction layer CPL (the light extraction layer CPL is arranged on the side of the cathode 2 away from the anode 1 as shown in Figure 6).
  • the front and back of “ ⁇ ” represent different film layer structures.
  • “ITO” represents the anode 1, wherein the anode 1 is made of ITO material (indium tin oxide material).
  • HTL’:HIL’,97:3,10nm means that the HTL’ material and the HIL’ material are doped to form the first hole injection layer HIL1, the mass doping ratio of the HTL’ material and the HIL’ material is 97:3, and the thickness of the first hole injection layer HIL1 is 10nm.
  • RH:RD,10% means that the RH material and the RD material are doped, and 10% means that the mass doping concentration of the RD material is 10%, that is, the ratio of the mass of the RD material to the sum of the masses of the RH material and the RD material.
  • ETL Liq,1:1,30nm
  • ETL ETL’:Liq,1:1,30nm
  • Yb,1nm means the electron injection layer EIL, wherein the electron injection layer EIL is made of Yb, and the thickness of the electron injection layer EIL is 1nm
  • Mg:Ag,13nm means the cathode 2, wherein the cathode 2 is made of Mg:Ag, and the thickness of the cathode 2 is 13nm.
  • CPL,60nm means the light extraction layer CPL (the light extraction layer CPL arranged on the side of the cathode 2 away from the anode 1 as shown in Figure 6), wherein the thickness of the light extraction layer CPL is 60nm. Similar parameter structures are represented in the same way, and the repeated parts are not repeated.
  • the membrane materials of Comparative Examples 1 to 3 and Examples 1 to 3 can be any combination of the above materials.
  • the membrane materials of Comparative Example 1 and Example 1 are the same.
  • the membrane materials of Comparative Example 2 and Example 2 are the same.
  • the membrane materials of Comparative Example 3 and Example 3 are the same.
  • the verification light-emitting layers of Comparative Examples 1-3 emitted light, indicating that the corresponding light-emitting devices of Comparative Examples 1-3 had carrier imbalance, consistent with the center being offset from the first light-emitting layer EML1.
  • the verification light-emitting layer did not emit light, demonstrating that the film thickness relationship of the light-emitting devices provided by the present disclosure can effectively improve the carrier balance in the light-emitting devices, thereby enhancing device performance.
  • the following comparative example 4 and multiple embodiments 4 to 13 are set up, wherein the light-emitting devices in comparative example 4 and multiple embodiments 4 to 13 include different hole transport materials, and the effects of light-emitting devices provided with different materials are verified.
  • Table 3 shows the hole transport materials corresponding to the general structural formula (1) and the general structural formula (2), respectively
  • Table 4 shows the device voltage and luminous efficiency (EQE) of the light-emitting devices of Comparative Example 4 and Examples 4 to 13 under a current density of 15 mA/ cm2 ; as well as the device life (LT95@1000nit) of the light-emitting devices of Comparative Example 4 and Examples 4 to 13 at a brightness of 1000nit.
  • EQE device voltage and luminous efficiency
  • the molecular structure of the hole transport layer material of the light-emitting device of Comparative Example 4 is:
  • the first hole transport subunit 311 includes at least a first hole transport layer HTL1;
  • the second hole transport subunit 321 includes at least a second hole transport layer HTL2;
  • the structural formulas (I) and (II) of the material of the first hole transport layer HTL1 and the material of the second hole transport layer HTL2 are respectively as follows:
  • Ar1 to Ar7 are selected from any one of the following structures:
  • * represents the position of connecting the general structural formula (1) or the position of the general structural formula (2).
  • L is selected from any one of the following structures:
  • the material of the hole transport layer of the light-emitting device of Example 4 is selected from compound 1, that is, in Example 4, the hole transport material corresponds to the above-mentioned general structural formula (1).
  • the material of the hole transport layer is compound 1, which has the above-mentioned general structural formula (1), wherein Ar1, Ar2, and Ar3 have the structures of the above-mentioned label 1, label 1, and label 17, respectively.
  • the voltage of the light-emitting device including the hole transport material of compound 1 is 98%, the EQE is 109%, and the life span is 111%.
  • the material of the hole transport layer of the light-emitting device of Example 5 is selected from compound 2.
  • the material of the hole transport layer is compound 2, which has the above-mentioned general structural formula (1), wherein Ar1, Ar2, and Ar3 have the structures of the above-mentioned label 2, label 2, and label 21, respectively.
  • the voltage of the light-emitting device including the hole transport material of compound 2 is 97%, the EQE is 104%, and the life span is 116%.
  • the material for the hole transport layer of the light-emitting device of Example 6 is selected from compound 3; the material for the hole transport layer of the light-emitting device of Example 7 is selected from compound 4; the material for the hole transport layer of the light-emitting device of Example 8 is selected from compound 5; the material for the hole transport layer of the light-emitting device of Example 9 is selected from compound 6, that is, in Example 9, the hole transport material corresponds to the above-mentioned general structural formula (II).
  • the material of the hole transport layer is compound 6, which has the above-mentioned general structural formula (II), wherein Ar1, Ar2, L, Ar3, and Ar4 have the structures of the above-mentioned label 2, label 3, label D, label 4, and label 1, respectively.
  • the light-emitting device including the hole transport material of compound 6 has a voltage of 99%, an EQE of 105%, and a lifetime of 105%.
  • the hole transport layer of the light-emitting device of Example 10 is made of compound 7; the hole transport layer of the light-emitting device of Example 11 is made of compound 8; the hole transport layer of the light-emitting device of Example 12 is made of compound 9; and the hole transport layer of the light-emitting device of Example 13 is made of compound 10.
  • the material selections for compounds 1 to 10 are shown in Table 3, and the corresponding properties of the light-emitting devices are shown in Table 4.
  • first hole transport layer HTL1 and second hole transport layer HTL2 the selection of hole transport layer (first hole transport layer HTL1 and second hole transport layer HTL2) materials disclosed in the present invention, combined with the actual film thickness, can achieve a series device with higher efficiency and lifespan.
  • the present disclosure also provides a display panel comprising the above-described embodiments and combinations thereof of multiple light-emitting devices of different colors, thereby realizing efficient and stable full-color tandem light-emitting devices.
  • the tandem light-emitting devices are, for example, tandem OLED devices.
  • FIG6 is a schematic diagram of a display panel provided by an embodiment of the present disclosure.
  • the plurality of light-emitting devices of different colors include a red light-emitting device R, a green light-emitting device G, and a blue light-emitting device B.
  • the red light-emitting device R, the green light-emitting device G, and the blue light-emitting device B each have a first electron blocking layer EBL1 made of a different material; the red light-emitting device R, the green light-emitting device G, and the blue light-emitting device B each have a second electron blocking layer EBL2 made of a different material; the red light-emitting device R, the green light-emitting device G, and the blue light-emitting device B each have a first light-emitting layer EML1 made of a different material; and the red light-emitting device R, the green light-emitting device G, and the blue light-emitting device B each have a second light-emitting layer EML2 made of a different material.
  • a light-emitting device primarily includes an anode 1, a cathode 2, a plurality of light-emitting units disposed between the anode 1 and the cathode 2, and a charge generation unit 4 disposed between adjacent light-emitting units.
  • the plurality of light-emitting units includes at least a first light-emitting unit 31 and a second light-emitting unit 32, with the first light-emitting unit 31 being closer to the anode 1 than the second light-emitting unit 32.
  • the first light-emitting unit 31 includes a first light-emitting layer EML1 and a first hole transport subunit 311 disposed on the side of the first light-emitting layer EML1 closer to the anode 1.
  • the second light-emitting unit 32 includes a second light-emitting layer EML2 and a second hole transport subunit 321 disposed on the side of the second light-emitting layer EML2 closer to the anode 1.
  • the charge generation unit 4 includes an N-type doped charge generation layer N-CGL and a P-type doped charge generation layer P-CGL disposed sequentially in a direction away from the anode 1.
  • the surface of the N-type doped charge generation layer N-CGL in contact with the P-type doped charge generation layer P-CGL is a first surface; the surface of the first light-emitting layer EML1 closer to the N-type doped charge generation layer N-CGL is a second surface, and the distance between the first surface and the second surface is a first distance L1.
  • the ratio of the thickness R_H of the first hole transport subunit 311 to the first distance L1 is between 6 and 10.
  • the ratio of the thickness G_H of the first hole transport subunit 311 to the first distance L1 is between 5 and 8.
  • the ratio of the thickness B_H of the first hole transport subunit 311 to the first distance L1 is between 4 and 6.
  • This embodiment coordinates and adjusts the distance of the hole transmission path and the distance of the electron transmission path in the first light-emitting unit 31 of each color light-emitting device, thereby ensuring the transmission balance of carriers (holes and electrons) in each color light-emitting device.
  • the thickness R_H of the first hole transport subunit 311 is between 170 nm and 230 nm.
  • the thickness G_H of the first hole transport subunit 311 is between 130 nm and 170 nm.
  • the thickness B_H of the first hole transport subunit 311 is between 90 nm and 130 nm.
  • the hole transmission path length of each color light-emitting device is increased to reduce the hole transmission rate, thereby balancing the transmission rates of holes and electrons so that the two are combined in their respective corresponding first light-emitting layers EML1, thereby ensuring the luminous stability of each color light-emitting device.
  • the first distance L1 is between 15 nm and 30 nm. This embodiment achieves a highly efficient and stable tandem light-emitting device by adjusting the first distance L1, i.e., the length of the transmission path of the electrons generated by the charge generation unit 4, to balance the transmission rate of the holes generated by the anode 1 and the transmission rate of the electrons generated by the charge generation unit 4.
  • the charge generation unit 4 includes an N-type doped charge generation layer N-CGL and a P-type doped charge generation layer P-CGL, arranged sequentially in a direction away from the anode 1.
  • the surface of the N-type doped charge generation layer N-CGL in contact with the P-type doped charge generation layer P-CGL is a first surface.
  • the surface of the second light-emitting layer EML2 proximal to the N-type doped charge generation layer N-CGL is a third surface, and the distance from the third surface to the first surface closest thereto is a second distance L2.
  • the surface of the second light-emitting layer EML2 proximal to the cathode 2 is a fourth surface, and the shortest distance from the fourth surface to the cathode 2 is a third distance L3.
  • the ratio of the second distance R_L2 to the third distance L3 is between 2 and 3.2.
  • the ratio of the second distance G_L2 to the third distance L3 is between 1.8 and 2.8.
  • the ratio of the second distance B_L2 to the third distance L3 is between 1.6 and 2.6.
  • the second distance L2 of the hole transmission path and the third distance L3 of the electron transmission path in the second light-emitting unit 32 of the light-emitting device of each color are adjusted in coordination, thereby ensuring the transmission balance of carriers (holes and electrons) in the light-emitting device of each color.
  • the second distance R_L2 is between 80 nm and 110 nm.
  • the second distance G_L2 is between 65 nm and 95 nm.
  • the second distance B_L2 is between 55 nm and 85 nm.
  • This embodiment increases the length of the hole transport path of each color light-emitting device to reduce the hole transport rate, thereby balancing the transport rates of holes and electrons so that the two are combined in the first light-emitting layer EML1 to ensure the luminous stability of the light-emitting device.
  • the thickness of the second hole transport subunit 321 is between 70nm and 90nm; for the green light-emitting device G, the thickness of the second hole transport subunit 321 is between 60nm and 80nm; for the blue light-emitting device B, the thickness of the second hole transport subunit 321 is between 50nm and 70nm.
  • the thickness of the second hole transport subunit 321 of each color light emitting device is increased to increase the second distance between the light emitting devices of each color, that is, to increase the length of the hole transport path, so as to balance the transport rates of holes and electrons.
  • multiple light-emitting devices of different colors reuse the same first hole injection layer HIL1, first hole transport layer HTL1, first hole blocking layer HBL1, charge generation unit 4, second hole transport layer HTL2, second hole blocking layer HBL2, electron transport layer ETL, electron injection layer EIL and cathode 2.
  • the so-called “reuse” here means that the film layer materials and thicknesses are the same. That is, the first hole injection layer HIL1 of light-emitting devices of different colors has the same material and thickness; the first hole transport layer HTL1 of light-emitting devices of different colors has the same material and thickness; the first hole blocking layer HBL1 of light-emitting devices of different colors has the same material and thickness; the charge generation unit 4 of light-emitting devices of different colors has the same material and thickness; the second hole transport layer HTL2 of light-emitting devices of different colors has the same material and thickness; the second hole blocking layer HBL2 of light-emitting devices of different colors has the same material and thickness; the electron transport layer ETL of light-emitting devices of different colors has the same material and thickness; the electron injection layer EIL of light-emitting devices of different colors has the same material and thickness; and the cathode 2 of light-emitting devices of different colors has the same material and thickness.
  • the first hole injection layer HIL1 of light-emitting devices of different colors can be formed as an integral structure, that is, the first hole injection layer HIL1 is provided as a whole layer.
  • the first hole transport layer HTL1 of light-emitting devices of different colors can be formed as an integral structure, that is, the first hole transport layer HTL1 is provided as a whole layer.
  • the display panel further includes a light extraction layer CPL disposed on a side of the cathode 2 facing away from the anode 1 .
  • the molecular structure of the material of the light extraction layer CPL is as follows:
  • the thickness of the light extraction layer CPL is between 55 nm and 65 nm.
  • the display panel further includes an encapsulation layer 5 disposed on the side of the light extraction layer CPL facing away from the cathode 2.
  • the encapsulation layer 5 may be a single-layer structure or a combination of multiple layers.
  • the encapsulation layer 5 when it is a multi-layer structure, it may include a first inorganic material layer, an organic material layer, and a second inorganic material layer, sequentially disposed in a direction away from the cathode 2.
  • an embodiment of the present disclosure further provides a method for manufacturing a display panel, which specifically includes the following steps S1 to S16.
  • Ultrasonic treatment is performed on a glass plate with indium tin oxide (ITO) in a cleaning agent, the ultrasonically treated glass plate is rinsed in deionized water, and then ultrasonically degreased in an acetone-ethanol mixed solvent, and then baked in a clean environment until the water is completely removed to form an anode 1 of the light-emitting device.
  • ITO indium tin oxide
  • step S2 Place the glass plate with the anode 1 prepared in step S1 in a vacuum chamber and evacuate the chamber to a pressure of 1 ⁇ 10-5 to 1 ⁇ 10-6 Pa. Vacuum evaporate a hole injection material HIL' and a hole transport material HTL' on the anode 1 at a doping mass ratio of 97:3 to a thickness of 10 nm to form a first hole injection layer HIL1.
  • the thickness of the first hole transport layer HTL1 is 100 nm.
  • first electron blocking layer EBL1 evaporating an electron blocking material on the side of the first hole transport layer HTL1 away from the first hole injection layer HIL1 to form a first electron blocking layer EBL1.
  • the material and thickness of the first electron blocking layer EBL1 corresponding to light emitting devices of different colors are different.
  • the first light-emitting layer EML1 includes a host material and a guest material and can be prepared by a multi-source co-evaporation method.
  • the host material, guest material, and thickness vary in light-emitting devices of different colors.
  • the thickness of the first hole blocking layer HBL1 is 5 nm.
  • N-CGL N-type doped charge generation layer
  • the N-type doped charge generation layer (N-CGL) is formed by doping multiple materials, for example, CGL:Li at a mass ratio of 9:1.
  • the N-type doped charge generation layer (N-CGL) can be prepared using a multi-source co-evaporation method.
  • the thickness of the N-type doped charge generation layer (N-CGL) is 20 nm.
  • P-CGL P-type doped charge generation layer
  • N-CGL N-type doped charge generation layer facing away from the first hole blocking layer (HBL1) using a multi-source co-evaporation method.
  • the P-type doped charge generation layer (P-CGL) includes a hole injection material doped into a hole transport material at a mass fraction of 10%.
  • the P-type doped charge generation layer (P-CGL) can be prepared using a multi-source co-evaporation method.
  • the thickness of the P-type doped charge generation layer (P-CGL) is 10 nm.
  • S9 Evaporate a hole transport material on the side of the P-type doped charge generation layer P-CGL away from the N-type doped charge generation layer N-CGL to form a second hole transport layer HTL2.
  • the thickness of the second hole transport layer HTL2 is 55 nm.
  • S10 Vapor-deposit an electron blocking material on the side of the second hole transport layer HTL2 away from the P-type doped charge generation layer P-CGL to form a second electron blocking layer EBL2.
  • the material and thickness of the second electron blocking layer EBL2 are different for light-emitting devices of different colors.
  • the second light-emitting layer EML2 includes a host material and a guest material and can be prepared using a multi-source co-evaporation method.
  • the host material, guest material, and thickness vary in light-emitting devices of different colors.
  • the thickness of the second hole blocking layer HBL2 is 5 nm.
  • An electron transport layer is formed on the side of the second hole-blocking layer (HBL2) facing away from the second light-emitting layer (EML2).
  • the ETL comprises an electron transport material and Liq doped together in a 1:1 mass ratio.
  • the ETL can be prepared using a dual-source co-evaporation method.
  • the thickness of the ETL is 30 nm.
  • S14 Evaporate an electron injection material on the side of the electron transport layer ETL away from the second hole blocking layer HBL2 to form an electron injection layer EIL.
  • the material of the electron injection layer EIL can be ytterbium (Yb).
  • the thickness of the electron injection layer EIL is 1 nm.
  • a cathode 2 is formed on the side of the electron injection layer (EIL) facing away from the electron transport layer (ETL).
  • the cathode 2 is made of Mg and Al doped together in a mass ratio of 8:2.
  • the cathode 2 can be prepared using a dual-source co-evaporation method.
  • the thickness of the cathode 2 is 13 nm.
  • a light extraction material is evaporated on the side of the cathode 2 facing away from the anode 1 to form a light extraction layer CPL.
  • the thickness of the light extraction layer CPL is 60 nm.
  • the substrate including the light extraction layer CPL can be encapsulated using glass UV encapsulation. If the encapsulation material is TFE (tetrafluoroethylene resin), lithium fluoride (LiF) or a low refractive index (refractive index n less than or equal to 1.6) organic material needs to be evaporated on the light extraction layer CPL.
  • TFE tetrafluoroethylene resin
  • LiF lithium fluoride
  • n refractive index
  • embodiments of the present disclosure further provide a display device comprising the display substrate of any of the aforementioned embodiments.
  • the display device may be, for example, a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, vehicle-mounted device, or any other product with a display function.
  • Other essential components of the display device are readily understood by those skilled in the art and are not detailed here, nor should they be construed as limitations of the present disclosure.

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Abstract

本公开提供一种发光器件和显示面板，属于显示技术领域。本公开的发光器件包括阳极、阴极、设置在阳极和阴极之间的多个发光单元、以及设置在相邻发光单元之间的电荷产生单元；多个发光单元中包括一个第一发光单元和一个第二发光单元，且第一发光单元相较于第二发光单元更靠近阳极；第一发光单元包括第一发光层、以及设置在第一发光层靠近阳极的一侧的第一空穴传输子单元；第二发光单元包括第二发光层、以及设置在第二发光层靠近阳极的一侧的第二空穴传输子单元；第一发光单元的第一空穴传输子单元的厚度大于第二发光单元的第二空穴传输子单元的厚度。

Description

发光器件和显示面板 技术领域
本公开属于显示技术领域，具体涉及一种发光器件和显示面板。
背景技术
串联式有机电致发光器件(Tandem OLED)在有机电致发光器件(Organic Light-Emitting Diode，OLED)的发展中应运而生。Tandem OLED具备高效率、高亮度的优点。然而，相关技术中的Tandem OLED存在不同颜色的发光器件的出光效率及寿命等性能不一致的问题。
发明内容
本公开旨在至少解决现有技术中存在的技术问题之一，提供一种发光器件和显示面板。
第一方面，解决本公开技术问题所采用的技术方案是一种发光器件，其包括阳极、阴极、设置在所述阳极和所述阴极之间的多个发光单元、以及设置在相邻所述发光单元之间的电荷产生单元；所述多个发光单元中至少包括一个第一发光单元和一个第二发光单元，且所述第一发光单元相较于所述第二发光单元更靠近所述阳极；所述第一发光单元包括第一发光层、以及设置在所述第一发光层靠近所述阳极的一侧的第一空穴传输子单元；所述第二发光单元包括第二发光层、以及设置在所述第二发光层靠近所述阳极的一侧的第二空穴传输子单元；以及所述第一发光单元的第一空穴传输子单元的厚度大于所述第二发光单元的第二空穴传输子单元的厚度。
在一些实施例中，所述电荷产生单元包括沿背离所述阳极方向依次设置的N型掺杂电荷产生层和P型掺杂电荷产生层；所述N型掺杂电荷产生层与所述P型掺杂电荷产生层接触的表面为第一表面；所述第一发光层靠近所述N型掺杂电荷产生层的表面为第二表面，所述第一表面到所述第二表面的距离为第一距离；所述第一空穴传输子单元的厚度与所述第一距离的比值在4至10之间。
在一些实施例中，所述第一距离在15nm～30nm之间。
在一些实施例中，所述第一发光单元还包括设置在所述第一发光层靠近所述阴极的第一空穴阻挡层；所述第一空穴阻挡层的厚度在5nm～10nm之间。
在一些实施例中，所述第一空穴传输子单元至少包括第一空穴传输层；所述第二空穴传输子单元至少包括第二空穴传输层；所述第一空穴传输层的材料和所述第二空穴传输层的材料的结构通式(一)如下：
其中，Ar1～Ar3均各自独立地选自氢、氘、腈基、硝基、羟基、羰基、酯基、酰亚胺基、酰胺基、烷基、环烷基、烷氧基、芳氧基、烷基硫基、芳基硫基、烷基磺酰基、芳基磺酰基、烯基、甲硅烷基、硼基、胺基、芳基膦基、氧化膦基、芳基、杂芳基中的任意一种；或者，Ar1～Ar3中任意相邻基团结合形成环；N表示氮原子。
在一些实施例中，所述第一空穴传输子单元至少包括第一空穴传输层；所述第二空穴传输子单元至少包括第二空穴传输层；所述第一空穴传输层的材料和所述第二空穴传输层的材料的结构通式(二)如下：
其中，Ar4～Ar7均各自独立地选自氢、氘、腈基、硝基、羟基、羰基、酯基、酰亚胺基、酰胺基、烷基、环烷基、烷氧基、芳氧基、烷基硫基、芳基硫基、烷基磺酰基、芳基磺酰基、烯基、甲硅烷基、硼基、胺基、芳基膦基、氧化膦基、芳基、杂芳基中的任意一种；或者，Ar4～Ar7中任意相邻基团结合形成环；L表示经取代或未经取代的亚芳基或亚杂芳基。
在一些实施例中，Ar1～Ar3选自以下任意一种结构：


其中，*表示连接结构通式(一)的位置或结构通式(二)的位置。
在一些实施例中，Ar4～Ar7选自以下任意一种结构：

其中，*表示连接结构通式(一)的位置或结构通式(二)的位置。
在一些实施例中，L选自以下任意一种结构：
在一些实施例中，所述第一空穴传输子单元包括沿背离所述阳极方向依次设置的第一空穴注入层、第一空穴传输层、第一电子阻挡层；所述第二空穴传输子单元包括沿背离所述阳极方向依次设置的第二空穴传输层和第二电子阻挡层。
第二方面，本公开实施例还提供了一种显示面板，其包括多个不同颜色的发光器件，所述多个不同颜色的发光器件包括红色发光器件、绿色发光器件和蓝色发光器件；每个发光器件包括阳极、阴极、设置在所述阳极和所述阴极之间的多个发光单元、以及设置在相邻所述发光单元之间的电荷产生单元；所述多个发光单元中至少包括一个第一发光单元和一个第二发光单元，且所述第一发光单元相较于所述第二发光单元更靠近所述阳极；所述第一发光单元包括第一发光层、以及设置在所述第一发光层靠近所述阳极的一侧的第一空穴传输子单元；所述第二发光单元包括第二发光层、以及设置在所述第二发光层靠近所述阳极的一侧的第二空穴传输子单元；以及所述第一发光单元的第一空穴传输子单元的厚度大于所述第二发光单元的第二空穴传输子单元的厚度。
在一些实施例中，所述电荷产生单元包括沿背离所述阳极方向依次设置的N型掺杂电荷产生层和P型掺杂电荷产生层；所述N型掺杂电荷产生层与所述P型掺杂电荷产生层接触的表面为第一表面；所述第一发光层靠近所述N型掺杂电荷产生层的表面为第二表面，所述第一表面到所述第二表面的距离为第一距离；对于所述红色发光器件，所述第一空穴传输子单元的厚度与所述第一距离的比值在6～10之间；对于所述绿色发光器件，所述第一空穴传输子单元的厚度与所述第一距离的比值在5～8之间；对于所述蓝色发光器件，所述第一空穴传输子单元的厚度与所述第一距离的比值在4～6之间。
在一些实施例中，所述红色发光器件的第一空穴传输子单元的厚度大于所述绿色发光器件的第一空穴传输子单元的厚度；以及所述绿色发光器件的第一空穴传输子单元的厚度大于所述蓝色发光器件的第一空穴传输子单元的厚度。
在一些实施例中，对于所述红色发光器件，所述第一空穴传输子单元的厚度在170nm～230nm之间；对于所述绿色发光器件，所述第一空穴传输子单元的厚度在130nm～170nm之间；对于所述蓝色发光器件，所述第一空穴传输子单元的厚度在90nm～130nm之间。
在一些实施例中，所述第一距离在15nm～30nm之间。
在一些实施例中，所述电荷产生单元包括沿背离所述阳极方向依次设置的N型掺杂电荷产生层和P型掺杂电荷产生层；所述N型掺杂电荷产生层与所述P型掺杂电荷产生层接触的表面为第一表面；所述第二发光层靠近所述N型掺杂电荷产生层的表面为第三表面，所述第三表面到与之距离最近的所述第一表面的距离为第二距离；所述第二发光层靠近所述阴极一侧的表面为第四表面，所述第四表面到所述阴极的最短距离为第三距离；对于所述红色发光器件，所述第二距离与所述第三距离的比值在2～3.2之间；对于所述绿色发光器件，所述第二距离与所述第三距离的比值在1.8～2.8之间；对于所述蓝色发光器件，所述第二距离与所述第三距离的比值在1.6～2.6之间。
在一些实施例中，对于所述红色发光器件，所述第二距离在80nm～110nm之间；对于所述绿色发光器件，所述第二距离在65nm～95nm之间；对于所述蓝色发光器件，所述第二距离在55nm～85nm之间。
在一些实施例中，对于所述红色发光器件，所述第二空穴传输子单元的厚度在70nm～90nm之间；对于所述绿色发光器件，所述第二空穴传输子单元的厚度在60nm～80nm之间；对于所述蓝色发光器件，所述第二空穴传输子单元的厚度在50nm～70nm之间。
在一些实施例中，所述第一空穴传输子单元包括沿背离所述阳极方向依次设置的第一空穴注入层、第一空穴传输层、第一电子阻挡层；以及所述第二空穴传输子单元包括沿背离所述阳极方向依次设置的第二空穴传输层和第二电子阻挡层。
在一些实施例中，所述多个发光器件的第一空穴注入层的厚度相同，且所述多个发光器件的第一空穴注入层具有一体结构；以及所述多个发光器件的第一空穴传输层的厚度相同，且所述多个发光器件的第一空穴传输层具有一体结构。
在一些实施例中，所述红色发光器件的第一电子阻挡层的厚度大于所述绿色发光器件的第一电子阻挡层的厚度；以及所述绿色发光器件的第一电子阻挡层的厚度大于所述蓝色发光器件的第一电子阻挡层的厚度。
在一些实施例中，所述红色发光器件的第二电子阻挡层的厚度大于所述绿色发光器件的第二电子阻挡层的厚度；以及所述绿色发光器件的第二电子阻挡层的厚度大于所述蓝色发光器件的第二电子阻挡层的厚度。
在一些实施例中，所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第一电子阻挡层的材料不同；所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第二电子阻挡层的材料不同；以及所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第一发光层的材料不同；所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第二发光层的材料不同。
附图说明
图1为本公开实施例提供的发光器件的结构示意图；
图2为本公开实施例提供的发光单元的子单元示意图；
图3为本公开实施例提供的一种载流子传输子单元的具体结构示意图；
图4为本公开实施例提供的发光器件中膜层间距示意图；
图5为本公开实施例提供的另一种载流子传输子单元的具体结构示意图；
图6为本公开实施例提供的显示面板的示意图。
具体实施方式
为使本公开实施例的目的、技术方案和优点更加清楚，下面将结合本公开实施例中附图，对本公开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。通常在此处附图中描述和示出的本公开实施例的组件可以以各种不同的配置来布置和设计。因此，以下对在附图中提供的本公开的实施例的详细描述并非旨在限制要求保护的本公开的范围，而是仅仅表示本公开的选定实施例。基于本公开的实施例，本领域技术人员在没有做出创造性劳动的前提下所获得的所有其他实施例，都属于本公开保护的范围。
除非另外定义，本公开使用的技术术语或者科学术语应当为本公开所属领域内具有一般技能的人士所理解的通常意义。本公开中使用的“第一”、“第二”以及类似的词语并不表示任何顺序、数量或者重要性，而只是用来区分不同的组成部分。同样，“一个”、“一”或者“该”等类似词语也不表示数量限制，而是表示存在至少一个。“包括”或者“包含”等类似的词语意指出现该词前面的元件或者物件涵盖出现在该词后面列举的元件或者物件及其等同，而不排除其他元件或者物件。“连接”或者“相连”等类似的词语并非限定于物理的或者机械的连接，而是可以包括电性的连接，不管是直接的还是间接的。“上”、“下”、“左”、“右”等仅用于表示相对位置关系，当被描述对象的绝对位置改变后，则该相对位置关系也可能相应地改变。
在本公开中提及的“多个或者若干个”是指两个或两个以上。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。字符“/”一般表示前后关联对象是一种“或”的关系。
在相关技术中，Tandem器件中载流子传输路径包括：第一发光单元中，空穴从阳极传输至第一发光层；电子从N-CGL层(N型掺杂电荷产生层)与P-CGL层(P型掺杂电荷产生层)界面传输至第一发光层。第二发光单元中，空穴从N-CGL层与P-CGL层界面传输至第二发光层；电子从阴极传输至第二发光层。然而，N-CGL层与第一发光层之间往往设置有空穴阻挡层，该空穴阻挡层为一层或多层有机层的组合，主要用于传输电子并阻挡空穴；另外，空穴阻挡层与N-CGL层直接接触时，还用于阻挡N-CGL层中掺杂的金属离子，防止金属离子的迁移，因此空穴阻挡层与N-CGL层之间存在较大的能级势垒，造成电子传输速率较低。与此同时，目前采用的空穴传输材料，对空穴传输速度更快，空穴注入效率更高，这就造成了空穴和电子的传输速率不平衡，最终导致空穴和电子不能在第一发光层中复合，或者复合区域较小，从而影响发光器件的发光效率和寿命。即，在靠近N-CGL层的第一发光层中，电子传输到第一发光层所需时间更长，因此，在空穴传输速率较大的情况下，需要加大靠近第一发光层的第一空穴传输子单元311的厚度，以延缓空穴达到第一发光层。
鉴于此，本公开实施例提供了一种发光器件，其实质上消除了由于相关技术的限制和缺陷而导致的一个或多个问题。
图1为本公开实施例提供的发光器件的结构示意图，如图1所示，发光器件包括阳极1、阴极2、设置在阳极1和阴极2之间的多个发光单元、以及设置在相邻发光单元之间的电荷产生单元4。其中，多个发光单元中至少包括一个第一发光单元31和一个第二发光单元32，且第一发光单元31相较于第二发光单元32更靠近阳极1。也即，本公开的发光器件为Tandem OLED器件，该Tandem OLED具备高效率、高亮度的优点。
图2为本公开实施例提供的发光单元的子单元示意图，如图1所示，第一发光单元31包括第一发光层EML1、以及设置在第一发光层EML1靠近阳极1的一侧的第一空穴传输子单元311；第二发光单元32包括第二发光层EML2、以及设置在第二发光层EML2靠近阳极1的一侧的第二空穴传输子单元321。其中，第一空穴传输子单元311主要用于传输阳极1或电荷产生单元4产生的空穴，提高空穴传输效率。第二空穴传输子单元321主要用于传输电荷产生单元4产生的空穴，提高空穴传输效率。
如图2所示，第一发光单元31还包括设置在第一发光层EML1靠近阴极2一侧的第一电子传输子单元312；第二发光单元32还包括设置在第二发光层EML2靠近阴极2一侧的第二电子传输子单元322。其中，第一电子传输子单元312主要用于传输电荷产生单元4产生的电子，提高电子传输效率；第二电子传输子单元322主要用于传输阴极2产生的电子，提高电子传输效率。
示例性的，多个发光单元中包括一个第一发光单元31和一个第二发光单元32。又示例性的，多个发光单元中包括多个第一发光单元31和一个第二发光单元32。在多个发光单元中包括多个第一发光单元31和一个第二发光单元32的情况下，多个第一发光单元31中的至少部分第一发光单元31的第一空穴传输子单元311的厚度大于第二发光单元32的第二空穴传输子单元321的厚度。
以发光器件包括一个第一发光单元31、一个电荷产生单元4和一个第二发光单元32为例进行说明。在电场作用下，发光器件中的阳极1产生空穴，阴极2产生电子；电荷产生单元4同样形成空穴和电子，并分离。阳极1产生的空穴通过第一空穴传输子单元311传输至第一发光层EML1，电荷产生单元4产生的电子可以通过第一电子传输子单元312传输至第一发光层EML1；以及，电荷产生单元4产生的空穴通过第二空穴传输子单元321传输至第二发光层EML2，阴极2产生的电子可以通过第二电子传输子单元322传输至第二发光层EML2。空穴和电子迁移到第一发光层EML1(或第二发光层EML2)，在第一发光层EML1(或第二发光层EML2)复合产生激子，激子辐射跃迁发光。
图3为本公开实施例提供的一种载流子传输子单元的具体结构示意图。示例性的，如图3所示，第一空穴传输子单元311至少包括第一空穴传输层HTL1，第二空穴传输子单元321至少包括第二空穴传输层HTL2，第一电子传输子单元312至少包括第一空穴阻挡层HBL1，第二电子传输子单元322至少包括第二空穴阻挡层HBL2。第一空穴阻挡层HBL1为一层或多层有机层的组合，主要用于传输电子并阻挡空穴；另外，第一空穴阻挡层HBL1与电荷产生单元4直接接触时，还用于阻挡电荷产生单元4中掺杂的金属离子，防止金属离子的迁移，因此第一空穴阻挡层HBL1与电荷产生单元4之间存在较大的能级势垒，造成电子传输速率较低。
本公开实施例中第一发光单元31的第一空穴传输子单元311的厚度大于第二发光单元32的第二空穴传输子单元321的厚度。相比于现有技术，本公开实施例通过调整各个颜色发光器件的第一空穴传输子单元311的厚度和/或第二空穴传输子单元321的厚度，例如增大第一发光单元31的第一空穴传输子单元311的厚度，使得第一空穴传输子单元311的厚度大于第二空穴传输子单元321的厚度，也即增大阳极1→第一发光层EML1的空穴传输路径，以增大空穴在第一空穴传输子单元311中的传输时间，从而平衡阳极1→第一发光层EML1的空穴传输速率和电荷产生单元4→第一发光层EML1的电子传输速率，从而确保空穴和电子同时到达第一发光层EML1内并且复合于第一发光层EML1内，进而确保发光器件的发光稳定性。
在一些实施例中，如图3所示，电荷产生单元4包括沿背离阳极1方向依次设置的N型掺杂电荷产生层N-CGL和P型掺杂电荷产生层P-CGL；N型掺杂电荷产生层N-CGL与P型掺杂电荷产生层P-CGL接触的表面为第一表面；第一发光层EML1靠近N型掺杂电荷产生层N-CGL的表面为第二表面，第一表面到第二表面的距离为第一距离L1。这里，第一距离L1可以理解为电荷产生单元4所产生的电子的传输距离，也即电子从产生起点到第一发光层EML1的电子传输路径的长度。
由于不同颜色发光器件的发光层的材料不同，第一空穴传输子单元311中子膜层的材料可能不同，因此不同颜色发光器件所对应的空穴迁移率、以及各膜层之间的能级差异不同。
在一些实施例中，第一空穴传输子单元311的厚度与第一距离L1的比值在4至10之间。
图4为本公开实施例提供的发光器件中膜层间距示意图，如图4所示，当发光器件为红色发光器件R时，第一空穴传输子单元311的厚度R_H与第一距离L1的比值在6～10之间。本实施例针对红色发光器件R所对应的第一发光单元31，通过配合调整该第一发光单元31中空穴传输路径的长度和电子传输路径的长度，使得第一空穴传输子单元311的厚度R_H与第一距离L1的比值在6～10之间，从而保证红色发光器件R内载流子(空穴和电子)的传输平衡。
具体地，当发光器件为绿色发光器件G时，第一空穴传输子单元311的厚度G_H与第一距离L1的比值在5～8之间。本实施例针对绿色发光器件G所对应的第一发光单元31，通过配合调整该第一发光单元31中空穴传输路径的长度和电子传输路径的长度，使得第一空穴传输子单元311的厚度G_H与第一距离L1的比值在5～8之间，从而保证绿色发光器件G内载流子(空穴和电子)的传输平衡。
具体地，当发光器件为蓝色发光器件B时，第一空穴传输子单元311的厚度B_H与第一距离L1的比值在4～6之间。本实施例针对蓝色发光器件B所对应的第一发光单元31，通过配合调整该第一发光单元31中空穴传输路径的长度和电子传输路径的长度，使得第一空穴传输子单元311的厚度B_H与第一距离L1的比值在4～6之间，从而保证蓝色发光器件B内载流子(空穴和电子)的传输平衡。
在一种可能的实施方式中，如图4所示，所述红色发光器件的第一空穴传输子单元的厚度R_H大于所述绿色发光器件的第一空穴传输子单元的厚度G_H；以及所述绿色发光器件的第一空穴传输子单元的厚度G_H大于所述蓝色发光器件的第一空穴传输子单元的厚度B_H。
在一种可能的实施方式中，如图4所示，当发光器件为红色发光器件R时，第一空穴传输子单元311的厚度R_H在170nm～230nm之间。这种实施方式相比现有技术(红色发光器件R的第一空穴传输子单元311的厚度大约在65nm左右)，通过增大红色发光器件R的第一空穴传输子单元311的厚度R_H，也即空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第一发光层REML1内，确保红色发光器件R的发光稳定性。
可选地，第一空穴传输子单元311的厚度R_H为170nm、200nm或230mn。
在一种可能的实施方式中，如图4所示，当发光器件为绿色发光器件G时，第一空穴传输子单元311的厚度G_H在130nm～170nm之间。这种实施方式相比现有技术(绿色发光器件G的第一空穴传输子单元311的厚度大约在45nm左右)，通过增大绿色发光器件G的第一空穴传输子单元311的厚度G_H，也即空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第一发光层GEML1内，确保绿色发光器件G的发光稳定性。
可选地，第一空穴传输子单元311的厚度G_H为130nm、150nm或170mn。
在一种可能的实施方式中，如图4所示，当发光器件为蓝色发光器件B时，第一空穴传输子单元311的厚度B_H在90nm～130nm之间。这种实施方式相比现有技术(蓝色发光器件B的第一空穴传输子单元311的厚度大约在35nm左右)，通过增大蓝色发光器件B的第一空穴传输子单元311的厚度B_H，也即空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第一发光层BEML1内，确保蓝色发光器件B的发光稳定性。
在一些实施例中，第一空穴传输子单元311包括第一空穴注入层HIL1、第一空穴传输层HTL1和第一电子阻挡层EBL1中的至少一者。
示例性的，如图3所示，第一空穴传输子单元311包括沿背离阳极1方向依次设置的第一空穴注入层HIL1、第一空穴传输层HTL1、第一电子阻挡层EBL1。其中，第一空穴注入层HIL1主要用于提高空穴注入效率，进而提高空穴传输效率。第一空穴传输层HTL1主要用于传输阳极1或电荷产生单元4产生的空穴，以提高空穴传输效率。第一电子阻挡层EBL1主要用于阻挡电子、以及传输空穴。
可以分别通过增大不同颜色发光器件的第一电子阻挡层EBL1的厚度，以平衡空穴和电子的传输速率。和/或，可以分别通过增大不同颜色发光器件的第一空穴传输层HTL1的厚度，以平衡空穴和电子的传输速率。
示例性的，如图4所示，红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第一空穴注入层HIL1的厚度相同，例如10nm，且红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第一空穴注入层HIL1具有一体结构。红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第一空穴传输层HTL1的厚度相同，例如100nm，且红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第一空穴传输层HTL1具有一体结构。红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第一电子阻挡层EBL1的厚度不同。例如，红色发光器件R对应的第一电子阻挡层REBL1的厚度大于绿色发光器件G对应的第一电子阻挡层GEBL1的厚度；以及绿色发光器件G对应的第一电子阻挡层GEBL1的厚度大于蓝色发光器件B对应的第一电子阻挡层BEBL1的厚度。例如，红色发光器件R对应的第一电子阻挡层REBL1的厚度为90nm；绿色发光器件G对应的第一电子阻挡层GEBL1的厚度为40nm；蓝色发光器件B对应的第一电子阻挡层BEBL1的厚度为5nm。
在一些实施例中，如图4所示，N型掺杂电荷产生层N-CGL和P型掺杂电荷产生层P-CGL之间的接触界面为第一表面，第一表面到与该N型掺杂电荷产生层N-CGL距离最近的第一发光层EML1的第二表面之间的距离，记作第一距离L1。第一距离L1在15nm～30nm之间。本实施例通过调整第一距离L1，也即电荷产生单元4所产生的电子的传输路径的长度，以平衡阳极1所产生的空穴的传输速率和电荷产生单元4所产生的电子的传输速率，实现高效、稳定的串联发光器件。
在一种可能的实施方式中，调整第一距离L1的方式可以是调整第一电子传输子单元312的厚度。如图3或图4所示，第一电子传输子单元312至少包括一层第一空穴阻挡层HBL1。第一空穴阻挡层HBL1主要用于阻挡空穴、阻挡N型掺杂电荷产生层N-CGL中掺杂的金属离子、以及传输电子。
具体地，第一空穴阻挡层HBL1的厚度在5nm～10nm之间。
这种实施方式相比现有技术，通过减薄第一空穴阻挡层HBL1的厚度，也即缩小电子传输路径的长度，以提高电子传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第一发光层EML1内，确保红色发光器件R的发光稳定性。
在另一种可能的实施方式中，图5为本公开实施例提供的另一种载流子传输子单元的具体结构示意图，如图5所示，第一电子传输子单元312包括第一空穴阻挡层HBL1和第一电子传输层ETL1，第一空穴阻挡层HBL1相比第一电子传输层ETL1更靠近第一发光层EML1。其中，第一电子传输层ETL1主要用于传输电荷产生单元4所产生的电子，提高电子传输效率。
具体地，第一空穴阻挡层HBL1的厚度在5nm～10nm之间。第一电子传输层ETL1的厚度在5nm～30nm之间。可以通过减薄第一空穴阻挡层HBL1和/或第一电子传输层ETL1的厚度，也即缩小电子传输路径的长度，以提高电子传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第一发光层EML1内，确保红色发光器件R的发光稳定性。
在一些实施例中，如图4所示，电荷产生单元4包括沿背离阳极1方向依次设置的N型掺杂电荷产生层N-CGL和P型掺杂电荷产生层P-CGL；N型掺杂电荷产生层N-CGL与P型掺杂电荷产生层P-CGL接触的表面为第一表面；第二发光层EML2靠近N型掺杂电荷产生层N-CGL的表面为第三表面，第三表面到与之距离最近的第一表面的距离为第二距离L2。这里，第二距离L2可以理解为电荷产生单元4所产生的空穴的传输距离，也即空穴从产生起点到第二发光层EML2的空穴传输路径的长度。
又或者，对于电荷产生单元4远离阳极1一侧的第一发光单元31，该第一发光单元31靠近N型掺杂电荷产生层N-CGL的表面到第一表面的距离，同样表示空穴从产生起点到该第一发光层EML1的空穴传输路径的长度。
为方便理解，本公开以一个第一发光单元31和一个第二发光单元32为例进行说明，不赘述多个第一发光单元31的情况。
第二发光层EML2靠近阴极2一侧的表面为第四表面，第四表面到阴极2的最短距离为第三距离L3，该第三距离L3可以理解为阴极2所产生的电子的传输距离，也即电子从产生起点到第二发光层EML2的电子传输路径的长度。
由于不同颜色发光器件的发光层的材料不同，第一空穴传输子单元311中子膜层的材料可能不同，因此不同颜色发光器件所对应的空穴迁移率、以及各膜层之间的能级差异不同。
具体地，如图4所示，当发光器件为红色发光器件R时，第二距离R_L2与第三距离L3的比值在2～3.2之间。本实施例针对红色发光器件R所对应的第二发光单元32，通过配合调整该第二发光单元32中空穴传输路径的第二距离R_L2和电子传输路径的第三距离L3，使得第二距离R_L2与第三距离L3的比值在2～3.2之间，从而保证红色发光器件R内载流子(空穴和电子)的传输平衡。
具体地，如图4所示，当发光器件为绿色发光器件G时，第二距离G_L2与第三距离L3的比值在1.8～2.8之间。本实施例针对绿色发光器件G所对应的第二发光单元32，通过配合调整该第二发光单元32中空穴传输路径的第二距离G_L2和电子传输路径的第三距离L3，第二距离G_L2与第三距离L3的比值在1.8～2.8之间，从而保证绿色发光器件G内载流子(空穴和电子)的传输平衡。
具体地，如图4所示，当发光器件为蓝色发光器件B时，第二距离B_L2与第三距离L3的比值在1.6～2.6之间。本实施例针对蓝色发光器件B所对应的第二发光单元32，通过配合调整该第二发光单元32中空穴传输路径的第二距离B_L2和电子传输路径的第三距离L3，使得第二距离B_L2与第三距离L3的比值在1.6～2.6之间，从而保证蓝色发光器件B内载流子(空穴和电子)的传输平衡。
在一种可能的实施方式中，如图4所示，当发光器件为红色发光器件R时，第二距离R_L2在80nm～110nm之间。这种实施方式相比现有技术(红色发光器件R的第二距离小于80nm)，通过增大红色发光器件R的第二距离R_L2，也即空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第二发光层REML2内，确保红色发光器件R的发光稳定性。
可选地，第二距离R_L2为85nm、95mn或110nm。
在一种可能的实施方式中，如图4所示，当发光器件为绿色发光器件G时，第二距离G_L2在65nm～95nm之间。这种实施方式相比现有技术(绿色发光器件G的第二距离在60nm左右)，通过增大绿色发光器件G的第二距离G_L2，也即空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第二发光层GEML2内，确保绿色发光器件G的发光稳定性。
可选地，第二距离G_L2为65nm、85mn或95nm。
在一种可能的实施方式中，如图4所示，当发光器件为蓝色发光器件B时，第二距离B_L2在55nm～85nm之间。这种实施方式相比现有技术(蓝色发光器件B的第二距离在50nm左右)，通过增大蓝色发光器件B的第二距离B_L2，也即空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第二发光层BEML2内，确保蓝色发光器件B的发光稳定性。
可选地，第二距离B_L2为55nm、70mn或85nm。
在一些实施例中，如图4所示，当发光器件为红色发光器件R时，增大红色发光器件R的第二距离R_L2的方式，具体包括：可以设置第二空穴传输子单元321的厚度在70nm～90nm之间，通过增大第二空穴传输子单元321的厚度，以增大红色发光器件R的第二距离R_L2。
如图4所示，当发光器件为绿色发光器件G时，增大绿色发光器件G的第二距离G_L2的方式，具体包括：可以设置第二空穴传输子单元321的厚度在60nm～80nm之间，通过增大第二空穴传输子单元321的厚度，以增大绿色发光器件G的第二距离G_L2。
如图4所示，当发光器件为蓝色发光器件B时，增大蓝色发光器件B的第二距离B_L2的方式，具体包括：可以设置第二空穴传输子单元321的厚度在50nm～70nm之间，通过增大第二空穴传输子单元321的厚度，以增大蓝色发光器件B的第二距离B_L2。
在一些可能的实施方式中，第二空穴传输子单元321包括第二空穴传输层HTL2和第二电子阻挡层EBL2中的至少一者。示例性的，如图3和图4所示，第二空穴传输子单元321包括沿背离阳极1方向依次设置的第二空穴传输层HTL2和第二电子阻挡层EBL2。其中，第二空穴传输层HTL2主要用于传输电荷产生单元4产生的空穴，以提高空穴传输效率。第二电子阻挡层EBL2主要用于阻挡电子、以及传输空穴。如图5所示，第二空穴传输子单元321包括沿背离阳极1方向依次设置的第二空穴注入层HIL2、第二空穴传输层HTL2和第二电子阻挡层EBL2。
可以分别通过增大不同颜色发光器件的第二电子阻挡层EBL2的厚度，以平衡空穴和电子的传输速率。和/或，可以分别通过增大不同颜色发光器件的第二空穴传输层HTL2的厚度，以平衡空穴和电子的传输速率。
示例性的，如图4所示，红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第二空穴传输层HTL2的厚度可以相同，例如为55nm。红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第二电子阻挡层EBL2的厚度不同。例如，红色发光器件R对应的第二电子阻挡层EBL2的厚度大于绿色发光器件G对应的第二电子阻挡层EBL2的厚度；以及绿色发光器件G对应的第二电子阻挡层EBL2的厚度大于蓝色发光器件B对应的第二电子阻挡层EBL2的厚度。例如，红色发光器件R对应的第二电子阻挡层EBL2的厚度为30nm；绿色发光器件G对应的第二电子阻挡层EBL2的厚度为20nm；蓝色发光器件B对应的第二电子阻挡层EBL2的厚度为5nm。
在一些实施例中，如图4所示，第二发光层EML2靠近阴极2一侧的表面为第四表面，第四表面到阴极2的最短距离为第三距离L3。第三距离L3在30nm～50nm之间。本实施例通过调整第三距离L3，也即阴极2所产生的电子的传输路径的长度，以平衡电荷产生单元4所产生的空穴的传输速率和阴极2所产生的电子的传输速率，实现高效、稳定的串联发光器件。
在一种可能的实施方式中，如图4所示，第二发光单元32还包括设置在第二发光层EML2靠近阴极2的一侧的第二电子传输子单元322。第二电子传输子单元322的厚度即为第三距离L3。第二电子传输子单元322包括沿背离阴极2方向依次设置的电子注入层EIL、电子传输层ETL和第二空穴阻挡层HBL2。其中，电子注入层EIL主要用于提高电子注入效率，进而提高电子传输效率。电子传输层ETL主要用于传输阴极2产生电子，以提高电子传输效率。第二空穴阻挡层HBL2主要用于阻挡空穴电子、以及传输电子。
在一种可能的实施方式中，如图5所示，第二发光单元32还包括设置在第二发光层EML2靠近阴极2的一侧的第二电子传输子单元322。第二电子传输子单元322包括沿背离阴极2方向依次设置的电子注入层EIL、第二电子传输层ETL2和第二空穴阻挡层HBL2。
另外，本公开还可以通过对空穴传输材料进行调整，选择能够平衡空穴、电子传输效率的空穴传输材料。
在一些实施例中，第一空穴传输子单元311至少包括第一空穴传输层HTL1；第二空穴传输子单元321至少包括第二空穴传输层HTL2；第一空穴传输层HTL1的材料和第二空穴传输层HTL2的材料的结构通式(一)如下：
其中，Ar1～Ar3均各自独立地选自氢、氘、腈基、硝基、羟基、羰基、酯基、酰亚胺基、酰胺基、烷基、环烷基、烷氧基、芳氧基、烷基硫基、芳基硫基、烷基磺酰基、芳基磺酰基、烯基、甲硅烷基、硼基、胺基、芳基膦基、氧化膦基、芳基、杂芳基中的任意一种；或者，Ar1～Ar3中任意相邻基团结合形成环；N表示氮原子。
在一些实施例中，第一空穴传输子单元311至少包括第一空穴传输层HTL1；第二空穴传输子单元321至少包括第二空穴传输层HTL2；第一空穴传输层HTL1的材料和第二空穴传输层HTL2的材料的结构通式(二)如下：
其中，Ar4～Ar7均各自独立地选自氢、氘、腈基、硝基、羟基、羰基、酯基、酰亚胺基、酰胺基、烷基、环烷基、烷氧基、芳氧基、烷基硫基、芳基硫基、烷基磺酰基、芳基磺酰基、烯基、甲硅烷基、硼基、胺基、芳基膦基、氧化膦基、芳基、杂芳基中的任意一种；或者，Ar4～Ar7中任意相邻基团结合形成环；L表示经取代或未经取代的亚芳基或亚杂芳基。
在一些实施例中，Ar1～Ar7选自以下任意一种结构：

其中，*表示连接结构通式(一)的位置或结构通式(二)的位置。
本实施例通过选择适配电子传输效率的第一空穴传输层HTL1的材料和第二空穴传输层HTL2的材料，以匹配电子注入和传输速率，实现高效、稳定的串联OLED器件。
在一些实施例中，L选自以下任意一种结构：
在一些实施例中，阴极2和阳极1均各自独立地包括选自银(Ag)、镁(Mg)、铜(Cu)、铝(Al)、铂(Pt)、钯(Pd)、金(Au)、镍(Ni)、钕(Nd)、铱(Ir)、铬(Cr)、锂(Li)、钙(Ca)、氟化锂/钙(LiF/Ca)、氟化锂/铝(LiF/Al)、钼(Mo)、肽(Ti)、铟(In)、锡(Sn)、锌(Zn)和镱(Yb)中的至少一种，或其氧化物。示例性的，发光器件为顶发射结构器件时，阳极1为具有反射性的电极，阴极2为具有透射性或半透射性的电极。示例性的，阳极1选自高功函数的材料，例如ITO/Ag/ITO叠层结构；阴极2选自为低功函数的材料，可以是半透射的金属或金属合金材料，例如为Ag/Mg合金材料。
在一些实施例中，空穴注入层(例如第一空穴注入层HIL1和第二空穴注入层HIL2)的材料可以包括但不限于掺杂在一起的强吸电子体系的p型掺杂剂和空穴传输材料。其中，p型掺杂剂可以包括2,3,6,7,10,11-六氰基-1,4,5,8,9,12-六氮杂苯并菲、2,3,5,6-四氟-7,7’,8,8’-四氰基对苯醌(F4TCNQ)、1,2,3-三[(氰基)(4-氰基-2,3,5,6-四氟苯基)亚甲基]环丙烷中的任意一种或多种的组合。空穴传输材料可以包括芳胺类空穴传输材料、二甲基芴类空穴传输材料、咔唑类空穴传输材料中的任意一种或多种的组合。例如，空穴传输材料可以包括4,4’-双[N-(1-萘基)-N-苯基氨基]联苯(NPB)、N,N’-双(3-甲基苯基)-N,N’-二苯基-[1,1’-联苯]-4,4’-二胺(TPD)、4-苯基-4’-(9-苯基芴-9-基)三苯基胺(BAFLP)、4,4’-双[N-(9,9-二甲基芴-2-基)-N-苯基氨基]联苯(DFLDPBi)、4,4’-二(9-咔唑基)联苯(CBP)和9-苯基-3-[4-(10-苯基-9-蒽基)苯基]-9H-咔唑(PCzPA)中的任意一种或多种的组合。
在一些实施例中，电子阻挡层(例如第一电子阻挡层EBL1和第二电子阻挡层EBL2)的材料可以包括，但不仅限于，芳胺类电子阻挡材料、二甲基芴类电子阻挡材料、咔唑类电子阻挡材料中的任意一种或多种的组合。例如，电子阻挡层的材料可以包括4,4’-双[N-(1-萘基)-N-苯基氨基]联苯(NPB)、N,N’-双(3-甲基苯基)-N,N’-二苯基-[1,1’-联苯]-4,4’-二胺(TPD)、4-苯基-4’-(9-苯基芴-9-基)三苯基胺(BAFLP)、4,4’-双[N-(9,9-二甲基芴-2-基)-N-苯基氨基]联苯(DFLDPBi)、4,4’-二(9-咔唑基)联苯(CBP)和9-苯基-3-[4-(10-苯基-9-蒽基)苯基]-9H-咔唑(PCzPA)中的任意一种或多种的组合。
在一些实施例中，发光层(例如第一发光层EML1和第二发光层EML2)的材料可以包括一种发光材料，也可以包括两种或两种以上的发光材料。例如，发光层(例如第一发光层EML1和第二发光层EML2)的材料可以包括主体发光材料和掺杂到主体发光材料中的客体发光材料；发光层的材料可以包括具有室温下热激活延迟荧光特性的发光材料，具有室温下荧光特性的发光材料，具有室温下磷光特性的发光材料。
示例性的，在发光器件为红色发光器件R时，第一发光层EML1的材料为红色发光材料，具体可以包括DCM类列红色发光材料和金属配合物类红色发光材料中的任意一种或多种的组合。例如，红色发光材料可以包括4-(二氰基亚甲基)-2-甲基-6-(4-二甲基氨基苯乙烯基)-4H-吡喃(DCM)、4-(二氰基甲撑)-2-叔丁基-6-(1,1,7,7-四甲基久洛尼啶-9-烯基)-4H-吡喃(DCJTB)，二(1-苯基异喹啉)(乙酰丙酮)铱(III)(Ir(piq)2(acac))、八乙基卟啉铂(简称：PtOEP)、二(2-(2’-苯并噻吩基)吡啶-N,C3’)(乙酰丙酮)合铱(简称：Ir(btp)2(acac)中的任意一种或多种的组合。
示例性的，在发光器件为绿色发光器件G时，第一发光层EML1的材料为绿色发光材料，具体可以包括香豆素染料、喹吖啶铜衍生物类绿色发光材料、多环芳香烃类绿色发光材料、二胺蒽衍生物类绿色发光材料、咔唑衍生物类绿色发光材料和金属配合物类绿色发光材料中的任意一种或多种的组合。例如，绿色发光材料可以包括香豆素6(C-6)、香豆素545T(C-525T)、喹吖啶铜(QA)、N,N’-二甲基喹吖啶酮(DMQA)、5,12-二苯基萘并萘(DPT)、N10,N10'-二苯基-N10,N10’-二苯二甲酰-9,9’-二蒽-10,10’-二胺(简称：BA-NPB)、三(8-羟基喹啉)合铝(III)(简称：Alq3)、三(2-苯基吡啶)合铱(Ir(ppy)3)、乙酰丙酮酸二(2-苯基吡啶)铱(Ir(ppy)2(acac))中的任意一种或多种的组合。
示例性的，在发光器件为蓝色发光器件B时，第一发光层EML1的材料为蓝色发光材料，具体可以包括芘衍生物类蓝色发光材料、蒽衍生物类蓝色发光材料、芴衍生物类蓝色发光材料、苝衍生物类蓝色发光材料、苯乙烯基胺衍生物类蓝色发光材料和金属配合物类蓝色发光材料中的任意一种或多种的组合。例如，蓝色发光材料可以包括N1,N6-二([1,1’-联苯]-2-基)-N1,N6-二([1,1’-联苯]-4-基)芘-1,6-二胺、9,10-二-(2-萘基)蒽(ADN)、2-甲基-9,10-二-2-萘基蒽(MADN)、2,5,8,11-四叔丁基苝(TBPe)、4,4’-二[4-(二苯氨基)苯乙烯基]联苯(BDAVBi)、4,4’-二[4-(二对甲苯基氨基)苯乙烯基]联苯(DPAVBi)、二(4,6-二氟苯基吡啶-C2,N)吡啶甲酰合铱(FIrpic)中的任意一种或多种的组合。
在一些实施例中，空穴阻挡层(例如第一空穴阻挡层HBL1和第二空穴阻挡层HBL2)的材料可以包括，但不仅限于，芳族杂环类空穴阻挡材料。具体地，空穴阻挡层(例如第一空穴阻挡层HBL1和第二空穴阻挡层HBL2)的材料可以包括苯并咪唑及其衍生物类空穴阻挡材料、咪唑并吡啶及其衍生物类空穴阻挡材料、苯并咪唑并菲啶衍生物类空穴阻挡材料、嘧啶及其衍生物类空穴阻挡材料、三嗪衍生物类空穴阻挡材料、吡啶及其衍生物类空穴阻挡材料、吡嗪及其衍生物类空穴阻挡材料、喹喔啉及其衍生物类空穴阻挡材料、二唑及其衍生物类空穴阻挡材料、喹啉及其衍生物类空穴阻挡材料、异喹啉衍生物类空穴阻挡材料、菲咯啉衍生物类空穴阻挡材料、二氮磷杂环戊二烯类空穴阻挡材料、氧化膦类空穴阻挡材料、芳族酮类空穴阻挡材料类空穴阻挡材料、内酰胺、硼烷类空穴阻挡材料中的任意一种或多种的组合。例如，空穴阻挡层的材料可以包括2-(4-联苯基)-5-(4-叔丁基苯基)-1,3,4-噁二唑(PBD)、1,3-双[5-(对叔丁基苯基)-1,3,4-噁二唑-2-基]苯(OXD-7)、3-(4-叔丁基苯基)-4-苯基-5-(4-联苯基)-1,2,4-三唑(TAZ)、3-(4-叔丁基苯基)-4-(4-乙基苯基)-5-(4-联苯基)-1,2,4-三唑(p-EtTAZ)、红菲咯啉(BPhen)、(BCP)、4,4’-双(5-甲基苯并噁唑-2-基)芪(BzOs)中的任意一种或多种的组合。
在一些实施例中，电子传输层ETL(又或者第一电子传输层ETL1和第二电子传输层ETL2)的材料包括，但不仅限于，苯并咪唑衍生物、咪唑并吡啶衍生物、苯并咪唑并菲啶衍生物等咪唑衍生物；嘧啶衍生物、三嗪衍生物等嗪衍生物；喹啉衍生物、异喹啉衍生物、菲咯啉衍生物等包含含氮六元环结构的化合物(也包括在杂环上具有氧化膦系的取代基的化合物，例如：OXD-7、TAZ、p-EtTAZ)、BPhen、BCP等。
在一些实施例中，电子注入层EIL的材料包括，但不仅限于，Li、Yb、Mg、Ca中的一种或多种的组合的化合物。
为了方便理解，下面本公开以一个具体示例对发光器件中各个膜层的材料进行列举说明。
空穴注入层(例如第一空穴注入层HIL1和第二空穴注入层HIL2)和P型掺杂电荷产生层P-CGL均包括掺杂在一起的空穴注入材料HIL’和空穴传输材料HTL’，其中空穴注入材料HIL’的分子结构为：
空穴传输材料HTL’的分子结构为：
红色发光器件R对应的电子阻挡层(第一电子阻挡层REBL1和第二电子阻挡层REBL2)的材料分子结构为：
绿色发光器件G对应的电子阻挡层(第一电子阻挡层GEBL1和第二电子阻挡层GEBL2)的材料分子结构为：
蓝色发光器件B对应的电子阻挡层(第一电子阻挡层BEBL1和第二电子阻挡层BEBL2)的材料分子结构为：
红色发光器件R对应的发光层(第一发光层REML1和第二发光层REML2)的材料包括主体材料(RH)和客体材料(RD)，其中主体材料(RH)包括P型掺杂主体材料(RH_P)和N型掺杂主体材料(RH_N)。其中，P型掺杂主体材料(RH_P)的分子结构为：
N型掺杂主体材料(RH_N)的分子结构为：
客体材料(RD)的分子结构为
示例性的，P型掺杂主体材料(RH_P)和N型掺杂主体材料(RH_N)的掺杂质量比为1:1。
绿色发光器件G对应的发光层(第一发光层GEML1和第二发光层GEML2)的材料包括主体材料(GH)和客体材料(GD)，其中主体材料(GH)包括P型掺杂主体材料(GH_P)和N型掺杂主体材料(GH_N)。其中，P型掺杂主体材料(GH_P)的分子结构为：
N型掺杂主体材料(GH_N)的分子结构为：
客体材料(GD)的分子结构为：
示例性的，P型掺杂主体材料(GH_P)和N型掺杂主体材料(GH_N)的掺杂质量比为1:1。
蓝色发光器件B对应的发光层(第一发光层BEML1和第二发光层BEML2)的材料包括主体材料(BH)和客体材料(BD)。其中，主体材料(BH)的分子结构为：
客体材料(BD)的分子结构为：
N型掺杂电荷产生层N-CGL的材料的分子结构为：
空穴阻挡层(例如第一空穴阻挡层HBL1和第二空穴阻挡层HBL2)的材料的分子结构为：
电子传输层ETL(又或者第一电子传输层ETL1和第二电子传输层ETL2)的材料包括掺杂在一起的电子传输材料ETL’和Liq。其中，电子传输材料ETL’的分子结构为：
Liq的分子结构为：
示例性的，电子传输层ETL中掺杂在一起的电子传输材料ETL’和Liq掺杂质量比为1:1。
以上是对发光器件结构、材料的详细说明。
针对上述各个实施例及其组合所构成的发光器件，对于结构改进后的发光器件的效果验证，本公开采用插层法随机筛选验证某几个实施例中的发光器件，证明本公开通过增加第一空穴传输子单元311和/或第二空穴传输子单元321的厚度，可以有效平衡载流子的传输速率，确保串联发光器件的高效、稳定。
插层法器件结构，在个别发光器件中插入与第一发光层EML1的发光颜色不同的验证发光层，如果验证发光层发光，说明载流子复合中心偏离了第一发光层EML1，在验证发光层处发生了复合，是影响发光器件的发光效率和寿命的。如果验证发光层不发光，说明载流子复合中心不曾偏离第一发光层EML1，在第一发光层EML1处发生了复合，不影响发光器件的发光效率。
对比例1：红色发光器件R的器件结构，ITO→HTL’:HIL’,97:3,10nm→HTL1,20nm→REBL1,35nm→REML1(RH:RD,5％),40nm→验证发光层EML1(GH:GD,10％),3nm→HBL1,5nm→N-CGL(CGL:Li,1％),20nm→P-CGL(HTL’:HIL’,90:10),10nm→HTL2,35nm→REBL2,35nm→REML2(RH:RD,5％),40nm→验证发光层EML2(GH:GD,10％),3nm→HBL2,5nm→ETL’:Liq,1:1,30nm→Yb,1nm→Mg:Ag,13nm→CPL,60nm。
实施例1：红色发光器件R的器件结构，ITO→HTL’:HIL’,97:3,10nm→HTL1,100nm→REBL1,90nm→REML1(RH:RD,5％),40nm→验证发光层EML1(GH:GD,10％),3nm→HBL1,5nm→N-CGL(CGL:Li,1％),20nm→P-CGL(HTL’:HIL’,90:10),10nm→HTL2,55nm→REBL2,30nm→REML2(RH:RD,5％),40nm→验证发光层EML2(GH:GD,10％),3nm→HBL2,5nm→ETL’:Liq,1:1,30nm→Yb,1nm→Mg:Ag,13nm→CPL,60nm。
对比例2：绿色发光器件G的器件结构，ITO→HTL’:HIL’,97:3,10nm→HTL1,20nm→GEBL1,15nm→GEML1(GH:GD,10％),30nm→验证发光层EML1(RH:RD,10％),3nm→HBL1,5nm→N-CGL(CGL:Li,1％),20nm→P-CGL(HTL’:HIL’,90:10),10nm→HTL2,35nm→GEBL2,15nm→GEML2(GH:GD,10％),30nm→验证发光层EML2(RH:RD,10％),3nm→HBL2,5nm→ETL’:Liq,1:1,30nm→Yb,1nm→Mg:Ag,13nm→CPL,60nm。
实施例2：绿色发光器件G的器件结构，ITO→HTL’:HIL’,97:3,10nm→HTL1,100nm→GEBL1,40nm→GEML1(GH:GD,10％),30nm→验证发光层EML1(RH:RD,10％),3nm→HBL1,5nm→N-CGL(CGL:Li,1％),20nm→P-CGL(HTL’:HIL’,90:10),10nm→HTL2,55nm→GEBL2,20nm→GEML2(GH:GD,10％),30nm→验证发光层EML2(RH:RD,10％),3nm→HBL2,5nm→ETL’:Liq,1:1,30nm→Yb,1nm→Mg:Ag,13nm→CPL,60nm。
对比例3：蓝色发光器件B的器件结构，ITO→HTL’:HIL’,97:3,10nm→HTL1,20nm→BEBL1,5nm→BEML1(BH:BD,2％),7nm→验证发光层EML1(RH:RD,10％),3nm→HBL1,5nm→N-CGL(CGL:Li,1％),20nm→P-CGL(HTL’:HIL’,90:10),10nm→HTL2,35nm→BEBL2,5nm→BEML2(BH:BD,2％),7nm→验证发光层EML2(RH:RD,10％),3nm→HBL2,5nm→ETL’:Liq,1:1,30nm→Yb,1nm→Mg:Ag,13nm→CPL,60nm。
实施例3：蓝色发光器件B的器件结构，ITO→HTL’:HIL’,97:3,10nm→HTL1,100nm→BEBL1,5nm→BEML1(BH:BD,2％),7nm→验证发光层EML1(RH:RD,10％),3nm→HBL1,5nm→N-CGL(CGL:Li,1％),20nm→P-CGL(HTL’:HIL’,90:10),10nm→HTL2,55nm→BEBL2,5nm→BEML2(BH:BD,2％),7nm→验证发光层EML2(RH:RD,10％),3nm→HBL2,5nm→ETL’:Liq,1:1,30nm→Yb,1nm→Mg:Ag,13nm→CPL,60nm。
需要说明的是，上述对比例1～3和实施例1～3中，“→”指向是从阳极到阴极再到光取出层CPL(如图6中所示的设置在阴极2背离阳极1一侧的光取出层CPL)的顺序。“→”前后分别表示不同膜层结构。“ITO”表示阳极1，其中，阳极1由ITO材料(氧化铟锡材料)制成。“HTL’:HIL’,97:3,10nm”表示HTL’材料和HIL’材料掺杂，形成第一空穴注入层HIL1，HTL’材料和HIL’材料的质量掺杂比为97:3，第一空穴注入层HIL1的厚度为10nm。“RH:RD,10％”表示RH材料和RD材料掺杂，10％表示RD材料质量掺杂浓度为10％，也即RD材料质量与RH材料和RD材料质量之和的比值。“ETL’:Liq,1:1,30nm”表示ETL’材料和Liq材料掺杂，形成第二电子传输层ETL2，ETL’材料和Liq材料质量掺杂比为1:1，第二电子传输层ETL2的厚度为30nm。“Yb,1nm”表示电子注入层EIL，其中，电子注入层EIL由Yb制成，且电子注入层EIL的厚度为1nm。“Mg:Ag,13nm”表示阴极2，其中，阴极2由Mg:Ag制成，且阴极2的厚度为13nm。“CPL,60nm”表示光取出层CPL(如图6中所示的设置在阴极2背离阳极1一侧的光取出层CPL)，其中，光取出层CPL的厚度为60nm。相似参数结构表示同理，重复部分不再赘述。
以上对比例1～3和实施例1～3各膜层材料可以选择上述任意材料的组合。对比例1和实施例1的各膜层材料选择相同。对比例2和实施例2各膜层材料选择相同。对比例3和实施例3各膜层材料选择相同。
上述对比例1～3和实施例1～3对比分析区别如表一所示。
表一

在电流密度15mA/cm2条件下，分别测得上述对比例1～3、以及实施例1～3的发光器件，得到器件光谱数据如表二所示。
表二
在插层法实验中，对比例1～3的验证发光层发光，说明对比例1～3对应的发光器件的载流子不平衡，符合中心偏离了第一发光层EML1的情况。而在符合本公开厚度关系的发光器件中，验证发光层不发光，说明本公开提供的发光器件的膜层厚度关系可以有效改善发光器件中载流子平衡情况，有利于提高器件性能。
针对上述各个实施例及其组合所构成的发光器件，通过设置以下对比例4和多个实施例4至13，其中，对比例4和多个实施例4至13中的发光器件包括不同的空穴传输材料，对设置有不同材料的发光器件的效果进行验证。
结合表三和表四，表三分别示出了结构通式(一)和结构通式(二)对应的空穴传输材料，表四示出了在电流密度15mA/cm2条件下，对比例4、实施例4～13的发光器件的器件电压、发光效率(EQE)；以及在1000nit亮度下，对比例4、实施例4～13的发光器件的器件寿命(LT95@1000nit)。
对比例4和多个实施例4至13中的包括不同的空穴传输材料的发光器件在电压、EQE以及寿命(LT95@1000nit)方面的性能。
对比例4的发光器件的空穴传输层的材料(如表四中所示的空穴传输材料HTL)的分子结构为：
如上所述，第一空穴传输子单元311至少包括第一空穴传输层HTL1；第二空穴传输子单元321至少包括第二空穴传输层HTL2；第一空穴传输层HTL1的材料和第二空穴传输层HTL2的材料的结构通式(一)和(二)分别如下：
结构通式(一)：
结构通式(二)：
在一些实施例中，Ar1～Ar7选自具有以下标号的结构中的任意一种：


其中，*表示连接结构通式(一)的位置或结构通式(二)的位置。
在一些实施例中，L选自具有以下标号的结构中的任意一种：
实施例4的发光器件的空穴传输层的材料选择化合物1，即，在实施例4中，空穴传输材料对应于上述结构通式(一)。具体地，空穴传输层的材料为化合物1，其具有上述结构通式(一)，其中，Ar1、Ar2、Ar3分别具有上述标号1、标号1、和标号17的结构。在实施例4中，包括化合物1的空穴传输材料的发光器件的电压为98％、EQE为109％以及寿命为111％。类似地，实施例5的发光器件的空穴传输层的材料选择化合物2。具体地，在实施例5中，空穴传输层的材料为化合物2，其具有上述结构通式(一)，其中，Ar1、Ar2、Ar3分别具有上述标号2、标号2、和标号21的结构。在实施例5中，包括化合物2的空穴传输材料的发光器件的电压为97％、EQE为104％以及寿命为116％。实施例6的发光器件的空穴传输层的材料选择化合物3；实施例7的发光器件的空穴传输层的材料选择化合物4；实施例8的发光器件的空穴传输层的材料选择化合物5；实施例9的发光器件的空穴传输层的材料选择化合物6，即，在实施例9中，空穴传输材料对应于上述结构通式(二)。具体地，空穴传输层的材料为化合物6，其具有上述结构通式(二)，其中，Ar1、Ar2、L、Ar3、Ar4分别具有上述标号2、标号3、标号D、标号4、和标号1的结构。在实施例9中，包括化合物6的空穴传输材料的发光器件的电压为99％、EQE为105％以及寿命为105％。类似地，实施例10的发光器件的空穴传输层的材料选择化合物7；实施例11的发光器件的空穴传输层的材料选择化合物8；实施例12的发光器件的空穴传输层的材料选择化合物9；实施例13的发光器件的空穴传输层的材料选择化合物10。上述化合物1～10的材料选择参见表三，发光器件的相应性能见表四。
表三
表四

由表四可知，本公开空穴传输层(第一空穴传输层HTL1和第二空穴传输层HTL2)材料的选择，结合实际膜层厚度，能够实现较高效率和寿命的串联器件。
另外，本公开实施例还提供了一种显示面板，具体包括上述各个实施例及其组合后的多个不同颜色的发光器件，实现高效稳定的全彩串联发光器件。串联发光器件例如为Tandem OLED器件。
在一些实施例中，图6为本公开实施例提供的显示面板的示意图。如图6所示，多个不同颜色的发光器件包括红色发光器件R、绿色发光器件G和蓝色发光器件B；红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第一电子阻挡层EBL1的材料不同；红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第二电子阻挡层EBL2的材料不同；红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第一发光层EML1的材料不同；红色发光器件R、绿色发光器件G和蓝色发光器件B各自对应的第二发光层EML2的材料不同。
在一些实施例中，发光器件主要包括阳极1、阴极2、设置在阳极1和阴极2之间的多个发光单元、以及设置在相邻发光单元之间的电荷产生单元4。其中，多个发光单元中至少包括一个第一发光单元31和一个第二发光单元32，且第一发光单元31相较于第二发光单元32更靠近阳极1。第一发光单元31包括第一发光层EML1、以及设置在第一发光层EML1靠近阳极1的一侧的第一空穴传输子单元311；第二发光单元32包括第二发光层EML2、以及设置在第二发光层EML2靠近阳极1的一侧的第二空穴传输子单元321。电荷产生单元4包括沿背离阳极1方向依次设置的N型掺杂电荷产生层N-CGL和P型掺杂电荷产生层P-CGL；N型掺杂电荷产生层N-CGL与P型掺杂电荷产生层P-CGL接触的表面为第一表面；第一发光层EML1靠近N型掺杂电荷产生层N-CGL的表面为第二表面，第一表面到第二表面的距离为第一距离L1。
对于红色发光器件R，第一空穴传输子单元311的厚度R_H与第一距离L1的比值在6～10之间。对于绿色发光器件G，第一空穴传输子单元311的厚度G_H与第一距离L1的比值在5～8之间。对于蓝色发光器件B，第一空穴传输子单元311的厚度B_H与第一距离L1的比值在4～6之间。
本实施例通过配合调整各个颜色发光器件的第一发光单元31中空穴传输路径的距离和电子传输路径的距离，从而保证各个颜色发光器件内载流子(空穴和电子)的传输平衡。
在一些实施例中，对于红色发光器件R，第一空穴传输子单元311的厚度R_H在170nm～230nm之间。对于绿色发光器件G，第一空穴传输子单元311的厚度G_H在130nm～170nm之间。对于蓝色发光器件B，第一空穴传输子单元311的厚度B_H在90nm～130nm之间。
本实施例，通过增大各个颜色发光器件的空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于各自对应的第一发光层EML1内，确保各个颜色的发光器件的发光稳定性。
在一些实施例中，第一距离在15nm～30nm之间。本实施例通过调整第一距离L1，也即电荷产生单元4所产生的电子的传输路径的长度，以平衡阳极1所产生的空穴的传输速率和电荷产生单元4所产生的电子的传输速率，实现高效、稳定的串联发光器件。
在一些实施例中，电荷产生单元4包括沿背离阳极1方向依次设置的N型掺杂电荷产生层N-CGL和P型掺杂电荷产生层P-CGL；N型掺杂电荷产生层N-CGL与P型掺杂电荷产生层P-CGL接触的表面为第一表面；第二发光层EML2靠近N型掺杂电荷产生层N-CGL的表面为第三表面，第三表面到与之距离最近的第一表面的距离为第二距离L2。第二发光层EML2靠近阴极2一侧的表面为第四表面，第四表面到阴极2的最短距离为第三距离L3。
对于红色发光器件R，第二距离R_L2与第三距离L3的比值在2～3.2之间。对于绿色发光器件G，第二距离G_L2与第三距离L3的比值在1.8～2.8之间。对于蓝色发光器件B，第二距离B_L2与第三距离L3的比值在1.6～2.6之间。
本实施例，通过配合调整各个颜色的发光器件的第二发光单元32中空穴传输路径的第二距离L2和电子传输路径的第三距离L3，从而保证各个颜色的发光器件内载流子(空穴和电子)的传输平衡。
在一些实施例中，对于红色发光器件R，第二距离R_L2在80nm～110nm之间。对于绿色发光器件G，第二距离G_L2在65nm～95nm之间。对于蓝色发光器件B，第二距离B_L2在55nm～85nm之间。
本实施例通过增大各个颜色的发光器件的空穴传输路径的长度，以降低空穴传输速率，从而平衡空穴和电子的传输速率，使之二者复合于第一发光层EML1内，确保发光器件的发光稳定性。
在一些实施例中，对于红色发光器件R，第二空穴传输子单元321的厚度在70nm～90nm之间；对于绿色发光器件G，第二空穴传输子单元321的厚度在60nm～80nm之间；对于蓝色发光器件B，第二空穴传输子单元321的厚度在50nm～70nm之间。
本实施例通过增大各个颜色的发光器件的第二空穴传输子单元321的厚度，以增大各个颜色发光器件的第二距离，也即增大空穴传输路径的长度，以平衡空穴和电子的传输速率。
在一些实施例中，如图6所示，多个不同颜色的发光器件复用同一第一空穴注入层HIL1、第一空穴传输层HTL1、第一空穴阻挡层HBL1、电荷产生单元4、第二空穴传输层HTL2、第二空穴阻挡层HBL2、电子传输层ETL、电子注入层EIL和阴极2。
这里所谓“复用”是指膜层材料、厚度均相同。也即，不同颜色的发光器件的第一空穴注入层HIL1的材料以及厚度相同；不同颜色的发光器件的第一空穴传输层HTL1的材料以及厚度相同；不同颜色的发光器件的第一空穴阻挡层HBL1的材料以及厚度相同；不同颜色的发光器件的电荷产生单元4的材料以及厚度相同；不同颜色的发光器件的第二空穴传输层HTL2的材料以及厚度相同；不同颜色的发光器件的第二空穴阻挡层HBL2的材料以及厚度相同；不同颜色的发光器件的电子传输层ETL的材料以及厚度相同；不同颜色的发光器件的电子注入层EIL的材料以及厚度相同；不同颜色的发光器件的阴极2的材料以及厚度相同。
在一些实施例中，不同颜色的发光器件的第一空穴注入层HIL1可以形成为整体结构，即，第一空穴注入层HIL1为整层设置。在一些实施例中，不同颜色的发光器件的第一空穴传输层HTL1可以形成为整体结构，即，第一空穴传输层HTL1为整层设置。
在一些实施例中，如图6所示，显示面板还包括设置在阴极2背离阳极1一侧的光取出层CPL。
光取出层CPL的材料的分子结构如下：
示例性的，光取出层CPL的厚度在55nm～65nm之间。
在一些实施例中，显示面板还包括设置在光取出层CPL背离阴极2一侧的封装层5。封装层5可以为单层结构，也可以为多层结构的组合。示例性的，封装层5为多层结构时，可以包括沿背离阴极2方向依次设置的第一无机材料层、有机材料层、第二无机材料层。
另外，本公开实施例还提供了一种显示面板的制备方法，该制备方法具体包括以下步骤S1～S16。
S1、将带有氧化铟锡(ITO)的玻璃板在清洗剂中进行超声处理，将超声处理后的玻璃板在去离子水中冲洗，然后在丙酮-乙醇混合溶剂中进行超声除油，接着在洁净环境下烘烤至完全除去水份，以形成发光器件的阳极1。
S2、将上述步骤S1带有阳极1的玻璃板置于真空腔内，抽真空至1×10-5～1×10-6Pa，在上述阳极1上以97:3的掺杂质量比例真空蒸镀空穴注入材料HIL’和空穴传输材料HTL’，材料厚度为10nm，以形成第一空穴注入层HIL1。
S3、在第一空穴注入层HIL1背离阳极1的一侧蒸镀空穴传输材料，以形成第一空穴传输层HTL1。第一空穴传输层HTL1的厚度为100nm。
S4、在第一空穴传输层HTL1背离第一空穴注入层HIL1的一侧蒸镀电子阻挡材料，以形成第一电子阻挡层EBL1。其中，不同颜色的发光器件对应的第一电子阻挡层EBL1的材料和厚度不同。
S5、在第一电子阻挡层EBL1背离第一空穴传输层HTL1的一侧蒸镀发光材料，以形成第一发光层EML1。第一发光层EML1包括主体材料和客体材料，可以利用多源共蒸的方法制备。其中，不同颜色的发光器件中主体材料、客体材料和厚度不同。
S6、在第一发光层EML1背离第一电子阻挡层EBL1的一侧蒸镀空穴阻挡材料，以形成第一空穴阻挡层HBL1。第一空穴阻挡层HBL1的厚度为5nm。
S7、在第一空穴阻挡层HBL1背离第一发光层EML1的一侧利用多源共蒸的方法形成N型掺杂电荷产生层N-CGL。N型掺杂电荷产生层N-CGL的材料为多种材料掺杂形成，例如CGL:Li，质量比为9:1，可以利用多源共蒸的方法制备N型掺杂电荷产生层N-CGL。N型掺杂电荷产生层N-CGL的厚度为20nm。
S8、在N型掺杂电荷产生层N-CGL背离第一空穴阻挡层HBL1的一侧利用多源共蒸的方法形成P型掺杂电荷产生层P-CGL。P型掺杂电荷产生层P-CGL的材料包括向空穴传输材料中掺杂质量分数为10％的空穴注入材料，可以利用多源共蒸的方法制备P型掺杂电荷产生层P-CGL。P型掺杂电荷产生层P-CGL的厚度为10nm。
S9、在P型掺杂电荷产生层P-CGL背离N型掺杂电荷产生层N-CGL的一侧蒸镀空穴传输材料，以形成第二空穴传输层HTL2。第二空穴传输层HTL2的厚度为55nm。
S10、在第二空穴传输层HTL2背离P型掺杂电荷产生层P-CGL的一侧蒸镀电子阻挡材料，以形成第二电子阻挡层EBL2。其中，不同颜色的发光器件对应的第二电子阻挡层EBL2的材料和厚度不同。
S11、在第二电子阻挡层EBL2背离第二空穴传输层HTL2的一侧形成蒸镀发光材料，以第二发光层EML2。第二发光层EML2包括主体材料和客体材料，可以利用多源共蒸的方法制备。其中，不同颜色的发光器件中主体材料、客体材料和厚度不同。
S12、在第二发光层EML2背离第二电子阻挡层EBL2的一侧蒸镀空穴阻挡材料，以形成第二空穴阻挡层HBL2。第二空穴阻挡层HBL2的厚度为5mn。
S13、在第二空穴阻挡层HBL2背离第二发光层EML2的一侧形成电子传输层ETL。电子传输层ETL的材料包括掺杂在一起的电子传输材料和Liq，二者的质量比为1:1，可以采用双源共蒸方法制备电子传输层ETL。电子传输层ETL的厚度为30nm。
S14、在电子传输层ETL背离第二空穴阻挡层HBL2的一侧蒸镀电子注入材料，以形成电子注入层EIL。电子注入层EIL的材料可以是镱(Yb)。电子注入层EIL的厚度为1nm。
S15、在电子注入层EIL背离电子传输层ETL的一侧形成阴极2。阴极2的材料包括掺杂在一起的Mg和Al，二者的质量比为8:2，可以采用双源共蒸方法制备阴极2。阴极2的厚度为13nm。
S16、在阴极2背离阳极1的一侧蒸镀光取出材料，以形成光取出层CPL。光取出层CPL的厚度为60nm。
上述包含光取出层CPL的基板可以采用玻璃UV封装方式进行封装。如果材料TFE(四氟乙烯树脂)封装，光取出层CPL上需要蒸镀氟化锂(LiF)或者低折射率(折射率n小于或等于1.6)的有机材料。
另外，本公开实施例还提供了一种显示装置，其包括上述实施例中任一项的显示基板。该显示装置例如可以为手机、平板电脑、电视机、显示器、笔记本电脑、数码相框、车载设备等任何具有显示功能的产品。对于该显示装置的其它必不可少的组成部分均为本领域的普通技术人员应该理解具有的，在此不做赘述，也不应作为对本公开的限制。
可以理解的是，以上实施方式仅仅是为了说明本公开的原理而采用的示例性实施方式，然而本公开并不局限于此。对于本领域内的普通技术人员而言，在不脱离本公开的精神和实质的情况下，可以做出各种变型和改进，这些变型和改进也视为本公开的保护范围。

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  1. 一种发光器件，其包括阳极、阴极、设置在所述阳极和所述阴极之间的多个发光单元、以及设置在相邻所述发光单元之间的电荷产生单元；
    所述多个发光单元中至少包括一个第一发光单元和一个第二发光单元，且所述第一发光单元相较于所述第二发光单元更靠近所述阳极；
    所述第一发光单元包括第一发光层、以及设置在所述第一发光层靠近所述阳极的一侧的第一空穴传输子单元；
    所述第二发光单元包括第二发光层、以及设置在所述第二发光层靠近所述阳极的一侧的第二空穴传输子单元；以及
    所述第一发光单元的第一空穴传输子单元的厚度大于所述第二发光单元的第二空穴传输子单元的厚度。
  2. 根据权利要求1所述的发光器件，其中，所述电荷产生单元包括沿背离所述阳极方向依次设置的N型掺杂电荷产生层和P型掺杂电荷产生层；所述N型掺杂电荷产生层与所述P型掺杂电荷产生层接触的表面为第一表面；所述第一发光层靠近所述N型掺杂电荷产生层的表面为第二表面，所述第一表面到所述第二表面的距离为第一距离；所述第一空穴传输子单元的厚度与所述第一距离的比值在4至10之间。
  3. 根据权利要求2所述的发光器件，其中，所述第一距离在15nm～30nm之间。
  4. 根据权利要求3所述的发光器件，其中，所述第一发光单元还包括设置在所述第一发光层靠近所述阴极的第一空穴阻挡层；所述第一空穴阻挡层的厚度在5nm～10nm之间。
  5. 根据权利要求1所述的发光器件，其中，所述第一空穴传输子单元至少包括第一空穴传输层；所述第二空穴传输子单元至少包括第二空穴传输层；
    所述第一空穴传输层的材料和所述第二空穴传输层的材料的结构通式(一)如下：
    其中，Ar1～Ar3均各自独立地选自氢、氘、腈基、硝基、羟基、羰基、酯基、酰亚胺基、酰胺基、烷基、环烷基、烷氧基、芳氧基、烷基硫基、芳基硫基、烷基磺酰基、芳基磺酰基、烯基、甲硅烷基、硼基、胺基、芳基膦基、氧化膦基、芳基、杂芳基中的任意一种；或者，Ar1～Ar3中任意相邻基团结合形成环；N表示氮原子。
  6. 根据权利要求1所述的发光器件，其中，所述第一空穴传输子单元至少包括第一空穴传输层；所述第二空穴传输子单元至少包括第二空穴传输层；
    所述第一空穴传输层的材料和所述第二空穴传输层的材料的结构通式(二)如下：
    其中，Ar4～Ar7均各自独立地选自氢、氘、腈基、硝基、羟基、羰基、酯基、酰亚胺基、酰胺基、烷基、环烷基、烷氧基、芳氧基、烷基硫基、芳基硫基、烷基磺酰基、芳基磺酰基、烯基、甲硅烷基、硼基、胺基、芳基膦基、氧化膦基、芳基、杂芳基中的任意一种；或者，Ar4～Ar7中任意相邻基团结合形成环；L表示经取代或未经取代的亚芳基或亚杂芳基。
  7. 根据权利要求5所述的发光器件，其中，Ar1～Ar3选自以下任意一种结构：

    其中，*表示连接结构通式(一)的位置或结构通式(二)的位置。
  8. 根据权利要求6所述的发光器件，其中，Ar4～Ar7选自以下任意一种结构：

    其中，*表示连接结构通式(一)的位置或结构通式(二)的位置。
  9. 根据权利要求6所述的发光器件，其中，L选自以下任意一种结构：
  10. 根据权利要求1所述的发光器件，其中，所述第一空穴传输子单元包括沿背离所述阳极方向依次设置的第一空穴注入层、第一空穴传输层、第一电子阻挡层；所述第二空穴传输子单元包括沿背离所述阳极方向依次设置的第二空穴传输层和第二电子阻挡层。
  11. 一种显示面板，其包括多个不同颜色的发光器件，所述多个不同颜色的发光器件包括红色发光器件、绿色发光器件和蓝色发光器件；
    每个发光器件包括阳极、阴极、设置在所述阳极和所述阴极之间的多个发光单元、以及设置在相邻所述发光单元之间的电荷产生单元；
    所述多个发光单元中至少包括一个第一发光单元和一个第二发光单元，且所述第一发光单元相较于所述第二发光单元更靠近所述阳极；
    所述第一发光单元包括第一发光层、以及设置在所述第一发光层靠近所述阳极的一侧的第一空穴传输子单元；
    所述第二发光单元包括第二发光层、以及设置在所述第二发光层靠近所述阳极的一侧的第二空穴传输子单元；以及
    所述第一发光单元的第一空穴传输子单元的厚度大于所述第二发光单元的第二空穴传输子单元的厚度。
  12. 根据权利要求11所述的显示面板，其中，
    所述电荷产生单元包括沿背离所述阳极方向依次设置的N型掺杂电荷产生层和P型掺杂电荷产生层；所述N型掺杂电荷产生层与所述P型掺杂电荷产生层接触的表面为第一表面；所述第一发光层靠近所述N型掺杂电荷产生层的表面为第二表面，所述第一表面到所述第二表面的距离为第一距离；
    对于所述红色发光器件，所述第一空穴传输子单元的厚度与所述第一距离的比值在6～10之间；对于所述绿色发光器件，所述第一空穴传输子单元的厚度与所述第一距离的比值在5～8之间；对于所述蓝色发光器件，所述第一空穴传输子单元的厚度与所述第一距离的比值在4～6之间。
  13. 根据权利要求12所述的显示面板，其中，所述红色发光器件的第一空穴传输子单元的厚度大于所述绿色发光器件的第一空穴传输子单元的厚度；以及所述绿色发光器件的第一空穴传输子单元的厚度大于所述蓝色发光器件的第一空穴传输子单元的厚度。
  14. 根据权利要求13所述的显示面板，其中，对于所述红色发光器件，所述第一空穴传输子单元的厚度在170nm～230nm之间；对于所述绿色发光器件，所述第一空穴传输子单元的厚度在130nm～170nm之间；对于所述蓝色发光器件，所述第一空穴传输子单元的厚度在90nm～130nm之间。
  15. 根据权利要求13或14所述的显示面板，其中，所述第一距离在15nm～30nm之间。
  16. 根据权利要求11所述的显示面板，其中，
    所述电荷产生单元包括沿背离所述阳极方向依次设置的N型掺杂电荷产生层和P型掺杂电荷产生层；所述N型掺杂电荷产生层与所述P型掺杂电荷产生层接触的表面为第一表面；所述第二发光层靠近所述N型掺杂电荷产生层的表面为第三表面，所述第三表面到与之距离最近的所述第一表面的距离为第二距离；所述第二发光层靠近所述阴极一侧的表面为第四表面，所述第四表面到所述阴极的最短距离为第三距离；
    对于所述红色发光器件，所述第二距离与所述第三距离的比值在2～3.2之间；对于所述绿色发光器件，所述第二距离与所述第三距离的比值在1.8～2.8之间；对于所述蓝色发光器件，所述第二距离与所述第三距离的比值在1.6～2.6之间。
  17. 根据权利要求16所述的显示面板，其中，对于所述红色发光器件，所述第二距离在80nm～110nm之间；对于所述绿色发光器件，所述第二距离在65nm～95nm之间；对于所述蓝色发光器件，所述第二距离在55nm～85nm之间。
  18. 根据权利要求16所述的显示面板，其中，对于所述红色发光器件，所述第二空穴传输子单元的厚度在70nm～90nm之间；对于所述绿色发光器件，所述第二空穴传输子单元的厚度在60nm～80nm之间；对于所述蓝色发光器件，所述第二空穴传输子单元的厚度在50nm～70nm之间。
  19. 根据权利要求11所述的显示面板，其中，所述第一空穴传输子单元包括沿背离所述阳极方向依次设置的第一空穴注入层、第一空穴传输层、第一电子阻挡层；以及
    所述第二空穴传输子单元包括沿背离所述阳极方向依次设置的第二空穴传输层和第二电子阻挡层。
  20. 根据权利要求19所述的显示面板，其中，所述多个发光器件的第一空穴注入层的厚度相同，且所述多个发光器件的第一空穴注入层具有一体结构；以及
    所述多个发光器件的第一空穴传输层的厚度相同，且所述多个发光器件的第一空穴传输层具有一体结构。
  21. 根据权利要求19所述的显示面板，其中，所述红色发光器件的第一电子阻挡层的厚度大于所述绿色发光器件的第一电子阻挡层的厚度；以及
    所述绿色发光器件的第一电子阻挡层的厚度大于所述蓝色发光器件的第一电子阻挡层的厚度。
  22. 根据权利要求21所述的显示面板，其中，所述红色发光器件的第二电子阻挡层的厚度大于所述绿色发光器件的第二电子阻挡层的厚度；以及
    所述绿色发光器件的第二电子阻挡层的厚度大于所述蓝色发光器件的第二电子阻挡层的厚度。
  23. 根据权利要求11所述的显示面板，其中，所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第一电子阻挡层的材料不同；所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第二电子阻挡层的材料不同；以及
    所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第一发光层的材料不同；所述红色发光器件、所述绿色发光器件和所述蓝色发光器件各自对应的第二发光层的材料不同。
PCT/CN2025/072988 2024-04-19 2025-01-17 发光器件和显示面板 Pending WO2025218296A1 (zh)

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Citations (3)

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CN101447555A (zh) * 2008-12-29 2009-06-03 中国科学院长春应用化学研究所 基于有机半导体异质结电荷产生层作为连接层的叠层有机电致发光器件及制法
CN104183722A (zh) * 2013-05-22 2014-12-03 海洋王照明科技股份有限公司 白光有机电致发光器件及其制备方法
CN115696948A (zh) * 2022-10-31 2023-02-03 京东方科技集团股份有限公司 叠层有机电致发光器件和显示装置

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Publication number Priority date Publication date Assignee Title
CN101447555A (zh) * 2008-12-29 2009-06-03 中国科学院长春应用化学研究所 基于有机半导体异质结电荷产生层作为连接层的叠层有机电致发光器件及制法
CN104183722A (zh) * 2013-05-22 2014-12-03 海洋王照明科技股份有限公司 白光有机电致发光器件及其制备方法
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