WO2023104104A1 - 发光装置、其制备方法以及包括发光装置的电子设备 - Google Patents

发光装置、其制备方法以及包括发光装置的电子设备 Download PDF

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WO2023104104A1
WO2023104104A1 PCT/CN2022/137281 CN2022137281W WO2023104104A1 WO 2023104104 A1 WO2023104104 A1 WO 2023104104A1 CN 2022137281 W CN2022137281 W CN 2022137281W WO 2023104104 A1 WO2023104104 A1 WO 2023104104A1
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Prior art keywords
layer
isolation structure
emitting device
light
substrate
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PCT/CN2022/137281
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English (en)
French (fr)
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WO2023104104A9 (zh
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甄常刮
高远
彭军军
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纳晶科技股份有限公司
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Publication of WO2023104104A9 publication Critical patent/WO2023104104A9/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H10K59/121—Active-matrix OLED [AMOLED] displays characterised by the geometry or disposition of pixel elements
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H10K59/122—Pixel-defining structures or layers, e.g. banks
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H10K59/123—Connection of the pixel electrodes to the thin film transistors [TFT]
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass

Definitions

  • the present disclosure relates to a light emitting device, a method of manufacturing the same, and an electronic device including the light emitting device.
  • a pixel definition layer for defining pixels is generally provided.
  • the pixel defining layer is in the form of an isolation structure (bank) for defining pixels (or sub-pixels), thereby separating the pixels (or sub-pixels).
  • the pixel defining layer is generally fabricated on a substrate (which is also referred to as a TFT substrate or a pixel substrate) on which active devices such as thin film transistors TFT are formed.
  • the height of the pixel defining layer is generally 1 ⁇ m ⁇ 2 ⁇ m or higher.
  • the printed ink droplets used for the functional layer are affected by the capillary effect at the isolation structure, and will form accumulations at the edge of the isolation structure after drying, resulting in uneven film layers. And the accumulation of functional layer materials at the edge of the isolation structure may not emit light or even emit light with low brightness.
  • the ink For example, recipes
  • additional processes or special techniques are used to enhance pixel isolation.
  • the present disclosure provides a novel light emitting device having improved performance, lifetime, uniformity of light emission, light emission area, reduced cost, and the like.
  • a light emitting device including: a first substrate; a plurality of first electrodes located on the first substrate; a plurality of isolation structures located on the first substrate and extending upward from the first substrate , at least a portion of each of the plurality of electrodes is disposed between corresponding isolation structures; and a stack of functional layers located at least on the plurality of first electrodes, the stack includes at least one of the The first functional layer on the plurality of first electrodes and the light emitting layer on the first functional layer, wherein the height of each of the plurality of isolation structures is less than 700 nanometers.
  • At least part of the side surface of the isolation structure has an inward recessed structure.
  • each of said isolation structures comprises a first portion and a second portion below said first portion, said first portion having a lateral dimension greater than said second portion.
  • each of the isolation structures has a substantially inverted trapezoidal cross section, and the included angle between the side surface of the inverted trapezoidal isolation structure and the first substrate is 30-85°.
  • the first portion of the isolation structure has a sharp portion at the side surface.
  • the top surface of the isolation structure is substantially flat, and the height of the top surface is greater than the height of the first functional layer.
  • the stack of functional layers includes: a plurality of first portions located on the plurality of first electrodes, and a plurality of second portions located on the top surfaces of the plurality of isolation structures, wherein Each of said first portions of said stack of functional layers is discontinuous.
  • the first functional layer includes: a plurality of first portions respectively located on the plurality of first electrodes, and a plurality of second portions located on the top surfaces of the plurality of isolation structures, wherein Each of said first portion and corresponding said second portion of said lower functional layer is discontinuous.
  • the stack further includes a second functional layer on the light emitting layer, and the light emitting device further includes: a second electrode on the stack.
  • said plurality of units of said emissive layer is formed by drying a layer of printed ink droplets, said ink droplets containing quantum dot material.
  • the plurality of isolation structures are formed of organic or inorganic insulating materials.
  • the height of each of the plurality of isolation structures is configured to be within the range: not higher than the sum of the stack height of the functional layer and 200 nanometers, and not lower than the The height of the first functional layer in the stack of the isolation structure.
  • a method for manufacturing a light-emitting device including: providing a first substrate; forming an isolation structure material layer on the first substrate; and etching the isolation structure material layer, so that A plurality of isolation structures are formed on the first substrate, wherein each of the plurality of isolation structures includes a first portion and a second portion below the first portion, the lateral dimension of the first portion is larger than that of the second portion The lateral dimension, wherein each of the plurality of isolation structures has a height of less than 700 nanometers.
  • etching the isolation structure material layer to form a plurality of isolation structures on the first substrate includes: forming a patterned mask on the isolation structure material layer; making the first the substrate and the direction of the ion or plasma flow to be used to etch the layer of isolation structure material are at an angle; maintaining said angle, utilizing said flow of ions while rotating said first substrate The isolation structure material layer is etched to form the plurality of isolation structures.
  • etching the isolation structure material layer to form a plurality of isolation structures on the first substrate comprises: forming a patterned mask on the isolation structure material layer; using an isotropic The etchant etches the isolation structure material layer to form the plurality of isolation structures.
  • each of the plurality of isolation structures is formed with a concave recessed structure at a side surface thereof.
  • the first substrate further includes a plurality of first electrodes formed thereon, and the plurality of isolation structures are formed such that the plurality of first electrodes are respectively located between corresponding isolation structures
  • the method also includes: forming a stack of functional layers, including: forming a first functional layer including a plurality of first portions on the plurality of first electrodes, wherein the first functional layer The plurality of first portions are discontinuous; forming a light emitting layer, the light emitting layer is located on the first functional layer; and forming a second functional layer, the second functional layer is located at least on the light emitting layer and forming a second electrode over the stack of functional layers.
  • forming the light-emitting layer includes: forming a plurality of units of the light-emitting layer by ink droplet printing and drying, the ink droplet contains quantum dot material, the plurality of units and the plurality of first electrodes Set accordingly.
  • the height of each of the plurality of isolation structures is configured to be in the range of not higher than the sum of the stack height of the functional layer and 200 nanometers, and not lower than the The height of said first functional layer in said stack of isolation structures.
  • each of the isolation structures has a substantially inverted trapezoidal cross section, and the included angle between the side surface of the inverted trapezoidal isolation structure and the first substrate is 30-85°.
  • the first portion of each of said isolation structures has a sharp portion at said side surface.
  • an electronic device including the light emitting device according to any embodiment or implementation manner of the present disclosure.
  • the light emitting device of the present disclosure may be implemented as a display device or a lighting device.
  • Figure 1 shows a schematic diagram of a light emitting device in the prior art
  • FIGS. 2A-2C illustrate schematic diagrams of light emitting devices according to some embodiments of the present disclosure
  • 3A and 3B show schematic diagrams of light emitting devices according to other embodiments of the present disclosure.
  • FIGS. 4A and 4B show schematic diagrams of light emitting devices according to other embodiments of the present disclosure.
  • Fig. 5 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure
  • Fig. 6 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure
  • FIGS. 7A-7D show schematic diagrams of a method of manufacturing a light emitting device according to an embodiment of the present disclosure
  • Fig. 8 shows a schematic diagram of a method for manufacturing a light-emitting device according to an embodiment of the present disclosure
  • Fig. 9 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • FIGS. 10A and 10B show photomicrographs and spheroid measurement results of a QLED light-emitting device according to Example 1 of the present disclosure
  • FIGS. 11A-11D show photomicrographs of monochrome and color QLED light emitting devices according to Example 1 of the present disclosure, respectively;
  • Figure 12 shows a photomicrograph of a QLED light-emitting device as Comparative Example 2;
  • FIG. 13 shows the results of spirometer measurements of QLEDs according to Example 2 of the present disclosure
  • FIG. 14 shows the results of spirometer measurements of QLEDs according to Example 3 of the present disclosure
  • FIG. 15 shows the results of sphenometry measurements of QLEDs according to Comparative Example 3.
  • 16A-16C are schematic diagrams showing the relationship between the unit of the printed light-emitting layer and the lower electrode according to one embodiment of the present disclosure
  • 17A and 17B are schematic diagrams showing the relationship between the units of the printed light-emitting layer and the lower electrodes according to another embodiment of the present disclosure.
  • the height of the isolation structure (bank) used as the pixel defining layer is generally several micrometers ( ⁇ m).
  • the functional layer such as the luminescent layer
  • ink droplets are affected by the capillary effect at the isolation structure, and will form accumulations at the edge of the isolation structure after drying, resulting in uneven film layers.
  • the accumulation of functional layer materials at the edge of the isolation structure may not emit light or even emit light with low brightness, thereby reducing the effective light emitting area and affecting the uniformity of light emission.
  • the uniformity of the film layer is affected by the isolation structure, it is difficult to achieve uniformity and flatness, especially in the case of multi-layer films.
  • the total thickness of the film layer of the device functional layer is usually hundreds of nanometers (for example, 100nm ⁇ 200nm, and the upper electrode is often thinner (typically, tens of nanometers, such as 20nm), so it is isolated from the micron level.
  • the upper electrode is often thinner (typically, tens of nanometers, such as 20nm), so it is isolated from the micron level.
  • the performance of the display device prepared by the printing method is often far lower than that prepared by the planar spin coating method. device.
  • Fig. 1 shows a schematic diagram of a light-emitting device prepared by a printing method in the prior art.
  • a plurality of electrodes (bottom electrodes) 103 and a pixel defining layer (which includes a plurality of isolation structures 105 ) for defining pixel regions are formed on a substrate 101 .
  • the functional layer ink is printed on the pixel area defined by the pixel defining layer, such as a light emitting layer or the like or stacks 107 , 109 and 111 including light emitting layers.
  • the printed ink droplets are affected by the capillary effect at the isolation structure, and the droplets will wet along the surface of the isolation structure, causing the film thickness at the edge to be larger than that at the center, so that after drying Material builds up at the edges of the isolation structure, resulting in an uneven film layer.
  • light-emitting diodes can include multi-layer films (such as hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, etc.), so it is more difficult to make multi-layer films by printing. until the film layer is even and smooth.
  • the upper electrode 113 generally covers the entire surface of the functional layer or stack of functional layers 107 , 109 and 111 and the top surface of the isolation structure, and is usually made relatively thin.
  • the total thickness of the electrode film layer in FIG. 1 is usually only a few hundred nanometers (nm), for example, in the range of 100nm-200nm.
  • the height of the isolation structure is usually several micrometers. Therefore, the height difference of the total thickness of the stack of the isolation structure and the functional layer is large, resulting in poor lap stability of the upper electrode at the isolation structure, and easily causing the upper electrode to break, as indicated by 121 in FIG. 1 .
  • the performance of the light emitting device prepared by the printing method is much lower than that of the light emitting device prepared by the planar spin coating method.
  • ppi pixel resolution
  • the size of a pixel is 84.66 ⁇ m, assuming that this pixel has four sub-pixels, and assuming that the sub-pixel interval is 10 ⁇ m, then the sub-pixel The area is 32 ⁇ m*32 ⁇ m.
  • the volume of a single sub-pixel 32*32*1 ⁇ m 3 , about 1 picoliter; assuming that the height of the isolation structure is 1.5 ⁇ m, the volume of a single sub-pixel at this time It will become about 1.5 picoliters; assuming that the nozzle is 1 picoliter, obviously the former is difficult to print, and there is a risk of overflow and color mixing.
  • the present disclosure addresses at least one or more of the above-mentioned problems, and provides a novel light-emitting device with improved light-emitting uniformity, light-emitting area, performance, lifetime, and the like.
  • FIG. 2A shows a schematic diagram of a light emitting device according to an embodiment of the present disclosure.
  • a light emitting device 200A includes a first substrate 101 .
  • the first substrate 101 may be a light-transmitting or opaque substrate, and may be a rigid or flexible substrate; the present disclosure is not limited thereto.
  • a plurality of first electrodes 103 and a plurality of isolation structures 105 are formed on the first substrate 101 .
  • the isolation structure 105 may serve as a pixel definition layer (PDL) that defines pixels.
  • the isolation structure 105 is located on the first substrate 101 and extends upward from the first substrate.
  • the isolation structure 105 may be formed of inorganic or organic materials.
  • the inorganic material is such as but not limited to silicon nitride.
  • the organic material may be, for example, photoresist including polyimide resin.
  • the first electrode 103 may also be referred to as a bottom electrode.
  • the first electrodes 103 may be disposed between corresponding isolation structures.
  • only one first electrode 103 is shown, which is arranged between corresponding two isolation structures 105 .
  • a portion of the isolation structure 105 may overlap the first electrode 103 .
  • at least a portion of the first electrode 103 is disposed between corresponding isolation structures.
  • FIG. 2A only shows a cross-sectional view of a part of the light-emitting device, so components such as the substrate 101 and the isolation structure 105 may not be all shown.
  • components such as the substrate 101 and the isolation structure 105 may not be all shown.
  • an unillustrated side of the isolation structure is not adjacent to the functional layer, there is no particular limitation on the side surface of the side.
  • the isolation structure 105 is configured with a height (H) smaller than 700 nm.
  • H height
  • the inventors of the present application have found that by setting the height of the isolation structure to 700nm or less, the unevenness of the film layer caused by the accumulation of the functional layer at the edge caused by the capillary effect at the isolation structure can be reduced, thereby improving the film layer. uniformity.
  • the step difference in thickness of the stack of the isolation structure and the functional layer can be reduced, thereby improving the overlap of the upper electrode and reducing breakage.
  • the height of the isolation structure is less than or equal to 500 nm, more preferably less than or equal to 400 nm, more preferably in the range of greater than 50 nm to 200 nm.
  • the edge of the functional layer of the pixel can be free from accumulation.
  • the height of the isolation structure is less than 200 nm, the problem of poor lap stability of the upper electrode (which is thinner) can be completely avoided.
  • the height of the isolation structure is no higher than beyond the stack of functional layers to be formed (i.e., all functional layers before forming the second electrode (upper electrode or top electrode (FIG. 5, 501)) for the pixel or light-emitting unit.
  • the height of the layer stack is 200nm, not lower than the height of the first layer of functional layer (usually it is a hole injection layer or a hole transport layer) next to the first electrode (lower electrode or bottom electrode 103).
  • the height of each of the plurality of isolation structures is configured to be within the range of not higher than the sum of the height of the stack of the functional layer and 100 nanometers (nm), and not lower than the height of the stack immediately adjacent to the stack The height of the functional layer next to the first electrode.
  • the comparison of the height is relative to a common reference object, generally, relative to the surface of the first substrate. Since the printed ink When tiled, the thickness is often several microns, and the reduced isolation structure has little influence on the flow of ink, so that the stacking at the edge of the functional layer can be reduced or eliminated, thereby increasing the effective light-emitting area of the pixel.
  • FIG. 2B shows a partially enlarged schematic view of some components of the light emitting device according to this embodiment.
  • FIG. 2B shows a complete isolation structure 105 .
  • the isolation structure 105 includes a first portion and a second portion below the first portion, the lateral dimension (L) of the first portion is greater than the lateral dimension (L) of the second portion.
  • the lateral direction refers to a direction substantially parallel to the surface of the substrate, that is, a substantially horizontal direction shown in the figure.
  • the cross-sections shown in FIGS. 2A and 2B are cross-sections across the isolation structure and light-emitting region of a pixel (or sub-pixel).
  • the isolation structure is shown as substantially an inverted trapezoid or similar to an inverted trapezoid; preferably, the included angle between the side surface of the inverted trapezoidal isolation structure and the first substrate is 30-85°.
  • the isolation structure can have various other shapes, for example, it can also be a semi-trapezoid, or other shapes in which the lower part is concave relative to the upper part, or the shapes in the embodiments that will be described later, such as rectangle or regular trapezoid, etc. .
  • one or more functional layers can be locally narrowed and Increase the resistance, or make it break so that it is not continuous (as shown in Figure 2A).
  • Certain functional layers eg, hole injection layers
  • have higher lateral conductivity (lower square resistance ratio) which may cause crosstalk between adjacent pixels.
  • the angle ⁇ between the inverted trapezoid of the isolation structure and the vertical line may be about 5°-60°.
  • the surface of the isolation structure can be treated with hydrophobicity, or the material of the isolation structure itself is hydrophobic.
  • the present disclosure is not limited thereto.
  • the light emitting device also includes a stack of functional layers including at least a light emitting layer.
  • the stack of functional layers may include a plurality of first portions on the plurality of first electrodes, wherein at least one layer of the plurality of first portions is discontinuous.
  • a plurality of first parts of the stack of functional layers respectively belong to different pixels (or sub-pixels), and one or some layers in the stack of functional layers of different pixels (or sub-pixels) are discontinuous .
  • the stack of functional layers may further include a second portion located on the top surface of the isolation structure, wherein at least one of the first portions of the stack of functional layers and the The corresponding at least one layer in the second portion is non-contiguous.
  • the light emitting device 200A further includes a functional layer 201 .
  • the functional layer 201 may be, for example, a hole injection layer (HIL), but the present disclosure is not limited thereto.
  • the functional layer 201 is formed on the first electrode 103 and the isolation structure 105.
  • the functional layer 201 can usually be coated on the entire surface of the substrate.
  • the lateral dimension (L) of the first part of the isolation structure is set to be larger than the lateral dimension (l) of the second part, the ink of the functional layer 201 is intercepted by the isolation structure 105 and occurs layer breaks.
  • the first portion 201_1 of the functional layer 201 on the first electrode 103 is broken from the second portion 201_2 on the top surface of the isolation structure. In this way, crosstalk between pixels caused by the lateral conduction of the functional layer 201 can be avoided. It should be noted that the second portion located on the top surface of the isolation structure does not have a practical effect on the light emitting device.
  • the top surface of the isolation structure 105 is substantially flat.
  • the height of the top surface of the isolation structure 105 is greater than the height of the functional layer 201 .
  • the top surface of the isolation structure 105 may be non-planar.
  • Figure 2C illustrates a light emitting device according to one embodiment of the present disclosure.
  • the light emitting device 200C shown in FIG. 2C may further include an additional functional layer 203 on the functional layer 201 .
  • the functional layer 203 may be, for example, a hole transport layer.
  • the light emitting device 200C may further include: a light emitting layer 205 on the functional layer 203 , and a functional layer 207 on the light emitting layer 205 .
  • the light emitting layer 205 may be a light emitting layer comprising quantum dot material.
  • the emissive layer can be formed by drying printed ink droplets containing quantum dot material.
  • the light emitting layer can also be formed by, for example, a spin coating method.
  • the functional layer 207 may be, for example, one or more layers of an electron transport layer, an electron blocking layer, an electron injection layer, and the like. In this way, a stack of functional layers (not shown) is formed. It should be understood that the examples of the above functional layers are only illustrative, not limiting.
  • the upper surface of the functional layer 203 is shown to be substantially flat, that is to say, it basically fills the space between the first part 201_1 and the second part 201_2 of the functional layer 201. height difference.
  • the configuration of the functional layer 203 can be realized by setting the height of the isolation structure 105 , the formulations of the functional layers 201 and 203 , the properties of the configured solution, the thickness of the film layer, and the like. This configuration achieves a substantially flat surface, which facilitates the preparation of subsequent functional layers.
  • other different configurations may be used, as will be further explained in the following embodiments.
  • the lower functional layer ie, the first functional layer below the light-emitting layer or the upper functional layer (ie, the second functional layer) is optional.
  • the lower functional layer is shown as two layers in FIGS. 2A and 2C , it may also be shown as a single layer with the upper functional layer 109 , but it may be multilayered.
  • the functional layer has a general meaning in the art.
  • the functional layer may mean: a layer for a light emitting unit disposed between two electrodes of the light emitting unit.
  • the functional layer may include at least one of the following: a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an electron blocking layer, and/or a buffer layer, among others.
  • an electrode or functional layer can be shared for two pixels.
  • the light emitting device 300A shown in FIG. 3A has substantially the same components as the light emitting device 200C shown in FIG. 2C , and the same components are denoted by the same reference numerals, and repeated description thereof will be omitted.
  • the difference between the light emitting device 300A shown in FIG. 3A and the light emitting device 200C shown in FIG. 2C is that the upper surface of the functional layer 203 is not flat, but is formed with depressions.
  • the light emitting layer 205 formed after the functional layer 203 fills the depression and has a substantially flat upper surface.
  • the light emitting device 300B shown in FIG. 3B has substantially the same components as the light emitting device 300A shown in FIG. 3A , and the same components are denoted by the same reference numerals, and repeated description thereof will be omitted.
  • the light emitting layer 205 formed after the functional layer 203 also fills the depression on the upper surface of the functional layer 203 .
  • the difference between the light emitting device 300B shown in FIG. 3B and the light emitting device 300A shown in FIG. 3A is that the light emitting layer 205 does not completely cover the entire upper surface of the functional layer 203 shown in the figure.
  • the printed ink droplets used to form the light emitting layer 205 may only form on a part of the surface of the functional layer 203 after drying.
  • the luminescent layer 205 is disposed corresponding to the first electrode 103 ; in addition, preferably, the orthographic projection of the luminescent layer 205 on the substrate 101 covers the corresponding orthographic projection of the first electrode 103 on the substrate 101 . In this way, the coverage of the first electrode 103 by the light-emitting layer 205 can be ensured, thereby improving the light emission of the device.
  • the upper functional layer 207 is in direct contact with the portion of the lower functional layer (eg, 203 ) not covered by the light emitting layer 205 .
  • the inventors of the present application have found that, in most cases, the direct contact between the upper functional layer and the lower functional layer on the light emitting layer has no significant impact on the device performance, because the conductive properties of the lower functional layer and the upper functional layer The conductivity is generally not high, so the potential lateral spread is limited, while the relatively high conductivity hole injection layer is preferably in a fractured state as shown in the figure. Even considering the influence of the direct contact between the upper functional layer and the lower functional layer on the performance of the device, its influence can be reduced or eliminated by selecting an appropriate material for the lower functional layer.
  • a light emitting device 400A includes a first substrate 101 .
  • a plurality of first electrodes 103 and a plurality of isolation structures 105 are formed on the first substrate 101 .
  • the isolation structure 105 may serve as a pixel definition layer (PDL) that defines pixels.
  • the isolation structure 105 is located on the first substrate 101 and extends upward from the first substrate. At least a portion of the electrodes 103 may be disposed between corresponding isolation structures.
  • the isolation structure 105 is configured such that a lateral dimension (L) of its first portion is set larger than a lateral dimension (l) of a second portion below the first portion.
  • the light emitting device 400A further includes a functional layer 201 .
  • the functional layer 201 may be, for example, a hole injection layer (HIL).
  • HIL hole injection layer
  • the functional layer 201 is formed on the first electrode 103 and the isolation structure 105 .
  • the first portion 201_1 of the functional layer 201 on the first electrode 103 is broken from the second portion 201_2 on the top surface of the isolation structure.
  • the light emitting device 400A may also include a further functional layer 203 on top of the functional layer 201 .
  • the functional layer 203 is also broken.
  • the functional layer 203 includes a first portion 203_1 located above the first electrode 103 and a second portion 203_2 located above the top surface of the isolation structure, which are separated from each other rather than continuous.
  • the functional layer 203 may be, for example, a hole transport layer.
  • Fig. 4B shows a schematic diagram of a light emitting device according to another embodiment.
  • the light emitting device 400B shown in FIG. 4B may further include: a light emitting layer 205 on the functional layer 203 , and a functional layer 207 on the light emitting layer 205 .
  • the light emitting layer 205 may be a light emitting layer comprising quantum dot material.
  • the emissive layer can be formed by drying printed ink droplets containing quantum dot material. In this way, a quantum dot display device can be formed.
  • at least a part of the light emitting layer 205 is printed in the area defined by the isolation structure 105 by a printing method.
  • the light emitting layer 205 may also exceed the boundary of the space formed by the stack.
  • the upper functional layer 207 substantially fills the depression in the space formed by the stack (if the light emitting layer 205 fails to completely fill the space).
  • the configuration of the functional layer 207 can be realized by setting the height of the isolation structure 105 , the formulations of the functional layers 201 and 203 , the luminescent layer 205 , the properties of the solution to be configured, the thickness of the film layer, and the like. This configuration achieves a substantially planar surface, which facilitates the preparation of the subsequent electrode (second electrode).
  • FIGS. 4A and 4B the same reference numerals are used for the same or corresponding components as those shown in FIGS. 2A-3B . Therefore, the above descriptions for each component can be applied here equally or adaptively, and detailed description thereof will not be repeated.
  • Fig. 5 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 500 shown in FIG. 5 further includes a second electrode (upper electrode) 501 on the stack of functional layers (not marked with reference numerals).
  • the second electrode 501 may be a full-surface electrode (or a blanket electrode), which may cover the functional layers of multiple pixels.
  • the present disclosure is not limited thereto.
  • the second electrode 501 may be configured to allow the light emitted by the light-emitting layer to transmit therefrom, for example, the second electrode 501 may be formed of a light-transmitting material such as ITO or a thin MgAg alloy. Exemplarily, the thickness of the second electrode 501 may be hundreds of nanometers, such as 100nm-200nm.
  • Corresponding portions of the light emitting layer 205, the corresponding first electrode 103, and the second electrode 501 may be included in the corresponding pixel.
  • the corresponding first electrode 103 , the corresponding part in the stack of functional layers, and the corresponding part of the second electrode 501 together constitute a light emitting unit (or called a light emitting device).
  • a pixel may include one or more light emitting units.
  • a pixel may also include a plurality of sub-pixels, each sub-pixel having a light emitting unit.
  • a pixel may include red, green and blue (RGB) three light emitting units (which may also be referred to as sub-pixels).
  • RGB red, green and blue
  • the term pixel in this application may represent a pixel or a sub-pixel unless otherwise specified or the context gives an opposite meaning.
  • the light emitting device 500 may further include a cover layer 503 disposed on the second electrode 501 .
  • the covering layer is configured to allow the light transmitted from the second electrode to pass through, and the covering layer can improve the light extraction efficiency of the device.
  • the cover layer may be composed of a high refractive index (n) material, typically n is greater than 1.65, preferably greater than 1.8.
  • the thickness of the covering layer can range from tens of nanometers to several thousand nanometers.
  • the light-emitting device may be a bottom-emission light-emitting device that emits light through the first electrode and the first substrate, a top-emission light-emitting device that emits light through the second electrode, or a double-sided light-emitting device that emits light through both.
  • Luminous type light emitting device may be a bottom-emission light-emitting device that emits light through the first electrode and the first substrate, a top-emission light-emitting device that emits light through the second electrode, or a double-sided light-emitting device that emits light through both.
  • the upper electrode 501 is further shown here based on the embodiment shown in FIG. 2A and FIG. 2C , those skilled in the art will understand based on the teachings of the present disclosure that the upper electrode 501 can be similarly or similarly formed in other embodiments. No specific description will be given here.
  • Fig. 6 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 600 includes a first substrate 101 .
  • a plurality of first electrodes 103 and a plurality of isolation structures 105 are formed on the first substrate 101 .
  • the isolation structure 105 may serve as a pixel definition layer (PDL) that defines pixels.
  • PDL pixel definition layer
  • the isolation structure 105 is located on the first substrate 101 and extends upward from the first substrate. At least a portion of the electrodes 103 may be disposed between corresponding isolation structures.
  • the isolation structure 105 of the light emitting device 600 is configured differently from the isolation structures shown in FIGS. 2A-5 .
  • the isolation structure 105 is also configured such that the lateral dimension of its first portion is set to be larger than the lateral dimension of the second portion below the first portion, this is achieved through the side surface (or sidewall) of the isolation structure 105 It is realized by forming the concave recess 611 on the top.
  • the recess 611 can be realized by, for example, wet etching or dry etching.
  • the light emitting device 600 also includes a functional layer 601 .
  • the functional layer 601 may be, for example, a hole injection layer (HIL).
  • HIL hole injection layer
  • the functional layer 601 is formed on the first electrode 103 and the isolation structure 105 .
  • the first portion 601_1 of the functional layer 601 on the first electrode 103 is broken from the second portion 601_2 on the top surface of the isolation structure.
  • openings are formed between isolation structures 105 as shown.
  • the upper surface of the open space is larger than the bottom surface. In this way, the fracture of the functional layer 601 can be promoted, so that the crosstalk can be further reduced.
  • forming a recess on the side surface of the isolation structure itself can make the isolation structure have a first part and a second part below the first part, and the first part The transverse dimension is greater than the transverse dimension of the second portion.
  • Concavities are further formed on the side surfaces, so that the fracture of the subsequently formed desired functional layer can be further promoted.
  • a sharp portion may be formed at the side surface of the isolation structure adjacent to the stack of functional layers to be formed, so as to cut off the liquid for forming the functional layer printed or applied to the substrate, so that the formed The functional layers (eg, the lower functional layer) are discontinuous.
  • the sharp portion may be formed by making the lateral dimension of the first portion of the isolation structure larger than that of said second portion or by recessing the side surface of the isolation structure.
  • the sharp portion is formed as high as possible on the side surface of the isolation structure, for example formed on the upper part of the side surface of the isolation structure, and its effect of intercepting the fluid will be due to being formed on the lower part of the side surface.
  • the formed functional layer may also be discontinuous by forming a depression on the side surface; similarly, the depression is preferably on the upper part of the side surface.
  • FIGS. 7A-7D show schematic diagrams of a method of manufacturing a light emitting device according to an embodiment of the present disclosure.
  • a first substrate 101 is provided on which a first electrode 103 is formed.
  • An isolation structure material layer 701 is formed on the first substrate 101 .
  • the isolation structure material layer 701 covers the first substrate 101 and the first electrode 103 .
  • the isolation structure material layer 701 may be formed of silicon nitride (Si 3 N 4 ); however, the present disclosure is not limited thereto.
  • the height of the isolation structure material layer can be set according to the height of the isolation structure to be formed, preferably, the height of the isolation structure material layer is less than 700 nanometers.
  • a patterned mask 703 is formed on the isolation structure material layer.
  • the mask 703 may be formed of photoresist, or may also be formed of a hard mask material.
  • the first substrate 101 and the direction of the ion or plasma flow 707 to be used for etching the isolation structure material layer 701 are made at an angle.
  • the first substrate 101 on which the mask pattern is formed can be placed on a stage (not shown) and snapped into place so that it is inclined at a certain angle relative to the rotation axis 705.
  • Angle ⁇ that is, an inclination of 90°- ⁇ with respect to the horizontal direction.
  • the first substrate 101 may be inclined at an angle smaller than or equal to 30 degrees relative to the horizontal direction.
  • the direction of the jet 707 of ions or plasma used for etching is substantially aligned with the direction of the rotation axis. Under the condition of maintaining the angle, while the first substrate 101 is rotated around the rotation axis 705, the isolation structure material layer is etched by the ion current. As an example, the rate of rotation is one revolution per minute.
  • the layers of isolation structural material are in an inverted trapezoidal shape, while the remaining isolation structural material layers on the right are in a trapezoidal shape. This is because the direction of etching (ie, the direction of ion flow or plasma flow) is angled relative to the substrate (or layer of isolation structure material).
  • the isolation structure material layers of the left side are in an inverted trapezoidal shape, while the remaining isolation structure material layers on the left are in a trapezoidal shape. This is because the direction of etching (ie, the direction of ion flow or plasma flow) is angled relative to the substrate (or layer of isolation structure material).
  • the substrate keeps rotating, so that multiple isolation structures with inverted trapezoidal cross-sections are formed on the left and right sides, as shown in FIG. 7D . Note that at least part of the isolation structure is only shown here for illustration.
  • the substrate can also be set substantially horizontal (or perpendicular to the rotation axis), and the angle of the ion or plasma flow used for etching relative to the rotation axis can be adjusted to form the isolation structure.
  • the isolation structure material layer may be etched with an isotropic etchant to form multiple isolation structures, as shown in FIG. 6 .
  • the isotropic etchant can be selected according to the material of the isolation structure and the material of the first electrode, so that its etching is selective to the material of the isolation structure.
  • Fig. 8 shows a schematic flowchart of a method for manufacturing a light emitting device according to some embodiments of the present disclosure.
  • a first substrate is provided, for example, the substrate 101 as described in the previous embodiments.
  • a plurality of lower electrodes may be formed on the first substrate.
  • an isolation structure material layer is formed on the first substrate.
  • the isolation structure material layer may be formed by chemical vapor deposition (CVD) using silicon nitride.
  • an isolation structure is formed.
  • a patterned mask is formed on the isolation structure material layer.
  • anisotropic dry etching is performed.
  • the isolation structure material layer may be etched with ion or plasma flow while the first substrate is rotated while maintaining the angle.
  • isotropic wet etching is performed.
  • the isolation structures formed each include a first portion and a second portion below the first portion, the first portion having a lateral dimension greater than the second portion.
  • each of the plurality of isolation structures is configured to have a height less than 700 nanometers (nm). In some embodiments, the height of each of the plurality of isolation structures is configured to be in the range of not higher than the sum of the height of the stack of functional layers and 200 nanometers (nm), and not lower than The height of the functional layer immediately adjacent to the first electrode in the stack.
  • Si 3 N 4 or SiO 2 may be used to form the isolation structure material layer, and CF 4 plasma gas may be used for etching.
  • the thickness of the Si 3 N 4 isolation structure material layer is 100 nm
  • the inclination angle of the substrate relative to the horizontal is about 30°
  • the rotation rate of the substrate is set at one revolution per minute.
  • the power supply is about 25kW
  • the bias power is about 25kW
  • the Si3N4 isolation structure material layer is etched with a flow rate of about 800sccm of CF4 gas and about 1000sccm of O2 gas .
  • each of the plurality of isolation structures is formed with a concave recess structure at a side surface thereof.
  • the recessed structure may be formed by wet etching.
  • a stack of functional layers is formed. Stacks of functional layers may be provided corresponding to the lower electrodes.
  • a lower functional layer is formed.
  • the lower functional layer includes a first portion located on the plurality of first electrodes, and a second portion located on the top surface of the plurality of isolation structures, wherein the first portion of the lower functional layer and the The second part is non-sequential.
  • the lower functional layer may be a single layer or multiple layers.
  • the underlying functionality may include one or more of a hole injection layer, a hole transport layer, and the like.
  • the hole injection layer can be prepared as follows: formulate the hole injection material into an ink formulation suitable for coating, select appropriate coating parameters, and perform coating.
  • the hole transport layer can be prepared as follows: formulate the material of the hole transport layer into a printable formula and print it; then transfer the substrate to a vacuum hot plate for drying. It should be understood that the method for preparing the lower functional layer described here is exemplary and not limiting; those skilled in the art will understand that various methods can be used to prepare the functional layer.
  • the thickness of the hole injection layer (HIL) can be in the range of tens to hundreds of nanometers, such as 20nm-300nm, preferably 30nm-150nm; the thickness of the hole transport layer (HTL) can be in the range of tens to hundreds of nanometers. The range of several hundred nanometers, for example 10nm-200nm, preferably 15nm-100nm.
  • a light emitting layer is formed, and the light emitting layer is located on the lower functional layer.
  • the plurality of units of the emissive layer are formed by inkjet printing and drying, the ink droplets containing quantum dot material.
  • the plurality of units may be disposed corresponding to the plurality of first electrodes.
  • the quantum dot (QD) light-emitting layer can be prepared as follows: after the QD stock solution is centrifuged and precipitated, the formula that is redispersed into the printing solvent is made into a printable ink and loaded into the printing device; according to the set printing parameters , the QD ink is accurately printed on the mutually independent electrode areas of the pixel substrate, and the corresponding bottom electrode area is completely covered; then the substrate is transferred to a vacuum hot plate for drying.
  • the thickness of the QD light-emitting layer may range from tens to hundreds of nanometers, such as 10nm-100nm, preferably 15nm-60nm.
  • an upper functional layer is formed, and the upper functional layer is located at least on the light emitting layer.
  • the upper functional layer may be a single layer or multiple layers.
  • the above-mentioned functional layer may include an electron transport layer and/or an electron injection layer, each of which may have a thickness ranging from tens to hundreds of nanometers, such as 10nm-400nm, preferably 20nm-100nm.
  • a second electrode located on the stack of functional layers is formed.
  • the second electrode may be configured to be formed entirely, covering the display area of one or more pixels (or sub-pixels).
  • a cover layer that can transmit light may be formed on the second electrode if light is extracted from the second electrode.
  • Fig. 9 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 900 may include a first substrate 901 and an opposite second substrate 905 .
  • a plurality of pixels 903 may be formed on the first substrate 901 .
  • the pixel 903 or at least its light emitting unit may be a pixel or a light emitting unit prepared according to the foregoing embodiments of the present disclosure.
  • a plurality of spacers 907 are formed on the second substrate 905 .
  • the first substrate 901 and the second substrate 905 are encapsulated by an encapsulation compound 911 , and a filler 909 may be filled between the first substrate 901 and the second substrate 905 .
  • spacer 907 is shown here as a trapezoidal interface, this is exemplary only and the present disclosure is not limited thereto, but may take any suitable shape.
  • the spacer 907 may be prepared by a printing method, for example, the spacer 907 may be formed by printing ink droplets at desired positions multiple times and drying.
  • the spacers 907 can also be obtained by depositing a spacer material (eg, an organic or inorganic insulating material) and patterning it (eg, by etching using a mask). The density and arrangement of the spacers are related to the pixel design and arrangement, and may be lower than the pixel resolution PPI.
  • Figures 16A-16C show schematic top views of the relationship of cells of a printed emissive layer to a lower electrode (also referred to as a bottom electrode) according to one embodiment of the present disclosure.
  • the isolation structure is not shown.
  • the lower electrode 103 is shown as circular.
  • the cells 205 of the luminescent layer are also shown as circular.
  • the unit 205 of the light emitting layer covers the lower electrode (ie, the first electrode) 103 . That is to say, the orthographic projection of the unit 205 of the light emitting layer on the first substrate 101 covers the corresponding orthographic projection of the first electrode 103 on the first substrate.
  • the light-emitting layer is fabricated by ink droplet printing.
  • the cells formed by ink droplet printing preferably cover the lower electrodes.
  • the radius of the circular unit 205 (which can be regarded as half of the lateral dimension (diameter)) formed after ink droplet drying is R
  • the radius of the lower electrode 103 is r
  • the accuracy of printing (for example, The deviation of ink drop point) is a.
  • the center of the circular unit 205 formed after the printed ink droplet dries coincides with (aligns with) the circular lower electrode 103 .
  • the alignment of the nozzles of the printing device with the lower electrode can be achieved through the built-in functions of the device (for example, automatic alignment of the CCD camera), and the accuracy of the landing point is determined by the printing device.
  • the radius R of the circular unit 205 formed after the ink drop is dried should be greater than or equal to the radius r of the lower electrode 103 and the printing accuracy (for example, the printing accuracy).
  • the sum of point errors) a that is, R ⁇ r+a. Therefore, it can be ensured that the units 205 of the light-emitting layer formed by printing can completely cover the lower electrode 103 under the condition of the printing accuracy a.
  • FIG. 16B shows two adjacent units 205 of the light emitting layer and corresponding adjacent two lower electrodes 103 .
  • the radii of the two units 205 are R1 and R2 respectively
  • the printing precisions are a1 and a2 respectively
  • the radii of the two lower electrodes 103 are r1 and r2 respectively. They respectively satisfy the above conditions, that is, R1 ⁇ r1+a1, R2 ⁇ r2+a2.
  • the center-to-center distance d between two adjacent lower electrodes 103 is configured to be greater than or equal to the sum of the radii R1 , R2 of the two units 205 and the printing accuracy a1 , a2 . That is, d ⁇ R1+R2+a1+a2.
  • the pitch d ⁇ 2R+2a ⁇ 2r+4a the pitch d ⁇ 2R+2a ⁇ 2r+4a.
  • the setting of the size of the film layer and the size and spacing of the lower electrodes after the ink droplets are dried can be designed according to different display resolutions, different pixel designs (for example, different geometric shapes and sizes), and whether partial overlapping designs are allowed. , equipment accuracy, etc. to consider.
  • the following situation may be considered.
  • Set the initial conditions 150ppi resolution, form 4 equal-sized circular lower electrodes (1 red, 1 green, 2 blue), and the accuracy of the printing equipment is 10 microns, as shown in Figure 16C.
  • the substrate resolution and pixel design determine the lower electrode spacing, the lower electrode spacing and printing equipment accuracy determine the upper limit of the diameter of the unit formed by the ink droplet, and the diameter of the unit formed by the ink droplet (experimental value) determines the upper limit of the radius of the lower electrode.
  • the circular lower electrode is just an example, and its opening ratio is relatively low as shown above, but it matches the natural drying shape of the printed ink droplet, and it is convenient to discuss the distance between the lower electrodes.
  • the same principle can be applied in actual products to configure cells and electrodes with desired geometries. For example, rectangular electrodes are used in an embodiment to be described later.
  • the radius R of the unit formed by ink drop printing may be affected by the following factors: ink formulation, size and shape of the lower electrode.
  • the formulation of the ink can be adjusted to change its spreading radius. Generally, the greater the surface tension of the ink, the smaller the spread, and the smaller the surface tension, the greater the spread.
  • the surface tension of the ink is mainly adjusted by the ratio of various solvents in the formula (the surface tension of different solvents is different). Therefore, according to actual needs, it can be adjusted so that the ink droplets of the formula are printed to just cover the lower electrode area and at the same time not flow to the lower electrode area of adjacent sub-pixels.
  • ink droplets comprising quantum dot materials may form cells with a diameter ratio of about 1.5:1 to about 1.1:1 before and after drying.
  • Adjusting the solid content of the ink can change the film thickness. Because in the embodiment of the present disclosure, there is no pixel isolation structure (no pixel defining part, such as isolation structure (bank)), so the thickness of the film layer cannot be changed by increasing or decreasing the number of printing ink droplets; The solid content of the formula itself is precisely controlled to meet the requirements of the spreading radius and film thickness.
  • volatilization rate of the ink can also be adjusted to adjust the spread radius, and the overall volatilization rate can be controlled so that the solute in the ink droplet just spreads to the required radius when the solvent with relatively high volatility is just about to volatilize completely. If the desired radius is not reached, it is possible that the solute cannot move because it becomes more viscous in the remaining solvent, resulting in incomplete coverage of the lower electrode area. If the highly volatile solvent has not yet volatilized after reaching the radius, it may exceed the radius required for spreading, and will interfere with adjacent sub-pixels, which may cause color mixing. It should be understood, however, that these are not limiting and may instead be utilized in certain circumstances.
  • FIGS. 17A and 17B are schematic diagrams showing the relationship between the units of the printed light-emitting layer and the lower electrodes according to another embodiment of the present disclosure.
  • the elongated pixels are taken as an example for illustration.
  • the unit 205 formed by printing ink droplets (multiple times) is strip-shaped with a width of L; the corresponding lower electrode is also strip-shaped with a width of l.
  • a substantially elongated or any other shaped unit of the light-emitting layer can be formed by printing a plurality of ink droplets and drying them.
  • the unit 205 is configured so that its half width (half of the lateral dimension, L/2) is greater than or equal to the half width (1/2) of the corresponding lower electrode 103 and the printing accuracy (a) And, that is, L/2 ⁇ l/2+a.
  • FIG. 17B shows the situation of adjacent cells 2051 and 2052 and corresponding adjacent lower electrodes 1031 and 1032 .
  • Each unit 2051 and 2052 is elongated and parallel in the direction in which it extends.
  • the corresponding lower electrodes 1031 and 1032 are each elongated and parallel in the direction in which they extend.
  • Each unit 2051 and 2052 and the corresponding lower electrodes 1031 and 1032 meet the aforementioned configuration, that is, the half-width (L/2) of the unit is greater than or equal to the half-width (1/2) of the corresponding lower electrode and the printing accuracy ( a) sum.
  • the center-to-center distance d between adjacent two lower electrodes 1031 and 1032 is configured to be greater than or equal to the sum of the half-widths L1/2, L2/2 of the two units 2051 and 2052 and the printing accuracy a1, a2. That is, d ⁇ L1/2+L2/2+a1+a2.
  • the pitch d ⁇ L+2a ⁇ l+4a the pitch d ⁇ L+2a ⁇ l+4a.
  • a substrate having a short isolation structure having a height greater than 50 nm (here, about 55 nm) as a pixel isolation structure is provided.
  • the cross section of the isolation structure is an inverted trapezoid (the angle between it and the horizontal is greater than or equal to 80° and less than 90°).
  • an isolation structure with a rectangular cross section may also be used.
  • a glass substrate on which an ITO transparent electrode (as a lower electrode) is formed is employed.
  • the substrate is cleaned.
  • solvent cleaning is performed on the substrate with the pixel isolation structure, and after drying and plasma surface treatment, a clean pixel substrate is obtained.
  • a hole injection layer and a hole transport layer are formed.
  • an aqueous solution of PEDOT:PSS which is a polymer of EDOT (3,4-ethylenedioxythiophene monomer)
  • PSS which is polystyrene sulfonate
  • a PEDOT:PSS layer is finally formed on the surface of ITO as a hole injection layer.
  • hole injection layer HIL
  • HTL hole transport layer
  • the thickness of the QD light-emitting layer may range from tens to hundreds of nanometers, such as 10nm-100nm, preferably 15nm-60nm.
  • a zinc oxide nanocrystalline thin film was fabricated.
  • the zinc oxide nanocrystal solution can be spin-coated on the light-emitting layer, for example, at a speed of 2500 rpm for 50 seconds. Annealing was performed in a glove box after the spin coating was completed. Finally, a layer of zinc oxide nanocrystalline film is formed on the surface of the light-emitting layer.
  • the above-mentioned functional layer may include an electron transport layer and/or an electron injection layer, each of which may have a thickness ranging from tens to hundreds of nanometers, such as 10nm-400nm, preferably 20nm-100nm.
  • the upper electrode is fabricated.
  • the device obtained after the zinc oxide nanocrystalline film is prepared can be placed in a vacuum evaporation chamber, and the cathode silver electrode can be evaporated.
  • the substrate on which the electrodes are evaporated can be bonded to the cover plate through UV glue, and after UV curing, the package can be completed for testing.
  • Example 2-3 substantially the same devices were fabricated using substantially the same conditions as in Example 1 above, except that the heights of the isolation structures were respectively 200 nm and 600 nm.
  • Comparative Example 1 a substrate without an isolation structure (non-pixel substrate, full-surface light emitting) was used, and all functional layer materials were consistent with those in the above example and had basically the same thickness, but were prepared by a spin coating process.
  • a glass substrate with an isolation structure of about 2.5 microns in height and an ITO electrode formed thereon is provided as a pixel substrate to print and prepare red, green and blue devices.
  • the preparation process of each corresponding film layer is the same as that of the above example, the difference is only The difference lies in the geometric size and shape of the isolation structure.
  • the lifespan of the device of Comparative Example 2 (the red, green and blue device prepared by using a pixel substrate with high isolation structure) is about 1/5 to 1/10 of that of the device of Comparative Example 1 (spin-coated non-pixel substrate device), while The lifetime of the same red, green and blue device prepared by using the pixel substrate with short isolation structure in Example 1 of the present disclosure is about 4/5 of that of the device in Comparative Example 1 (spin-coated non-pixel substrate device).
  • the lifetime of the printed QD light-emitting device is greatly improved.
  • FIGS. 10A and 10B show micrographs and profilometer measurement results of the QLED light emitting device according to the above-mentioned Example 1 of the present disclosure.
  • the edge accumulation of the functional layer of the pixel disappears, and the uniformity of the film thickness in the pixel is improved.
  • From the micrograph of Fig. 10A there is no edge push-up phenomenon.
  • From the step meter film thickness photo in Figure 10B it can be seen that the film layer in the pixel is uniform, which also verifies the phenomenon of no accumulation.
  • FIGS. 11A-11D show micrographs of monochrome and color QLED light-emitting devices prepared according to embodiments or examples of the present disclosure, respectively. From the micrographs of the QLED electroluminescent device according to the embodiment of the present disclosure shown in FIGS. 11A-11D , they are micrographs when red, green, blue, and red, green, and blue light up to emit light, respectively. It can be easily seen from these micrographs that the uniformity of light emission is very good.
  • FIG. 12 shows a microscope photo of the RGB three-color light emission of the QLED light emitting device with a high isolation structure in the above-mentioned comparative example 2. It can be seen from the photo that the red, green and blue pixels of the QLED light-emitting device of Comparative Example 2 all emit relatively dark light in areas around the isolation structure. This may be due to the high isolation structure height and capillary action.
  • FIG. 13 shows the results of spirometer measurement of QLEDs according to Example 2 of the present disclosure.
  • the difference from Example 1 is only that the height of the isolation structure is 200 nm.
  • the measurement result of the step meter shows that the stack of functional layers is basically flat, and there is no spectral line warping caused by stacking at the edge of the isolation structure.
  • FIG. 14 shows the results of spirometer measurement of QLEDs according to Example 3 of the present disclosure.
  • the difference from example 1 is only that the height of the isolation structure is 600 nm.
  • the measurement result of the step meter shows that the stacked layer of the functional layer is lifted up at the edge of the isolation structure, and there is an accumulation of about 18nm.
  • FIG. 15 shows the results of sphenometer measurement of the QLED according to Comparative Example 3.
  • the only difference from Example 1 is that the height of the isolation structure is 1000 nm.
  • the measurement result of the step meter shows that the stacked layer of the functional layer is lifted up at the edge of the isolation structure, and there is an accumulation of about 22 nm.
  • the stack of functional layers it is acceptable for the stack of functional layers to have a build-up of typically less than 20 nm at the edge at the isolation structure.
  • the height of the isolation structure is less than or equal to 200 nm, there is substantially no undesired accumulation of the functional layer at the edge of the isolation structure, which is preferable.
  • the height of the isolation structure is less than or equal to 50nm, since the isolation effect of the isolation structure on the fluid used to form the functional layer for printing or coating (including when drying) is weakened, although the functional layer may be flat, it may cause damage to the device.
  • the weakening of other characteristics of so a compromise consideration or further measures are required.
  • the side surface of the isolation structure may be formed with a concave recessed structure or the like.
  • a light emitting device may be implemented as a display device, such as a quantum dot display device; however, the present disclosure is not limited thereto.
  • an electronic device which may include the light emitting device according to any embodiment or implementation manner of the present disclosure.

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Abstract

本公开涉及发光装置、其制备方法以及包括发光装置的电子设备。一种发光装置，包括：第一基板；多个第一电极，位于第一基板之上；多个隔离结构，位于第一基板之上并从第一基板向上延伸，所述多个电极中的每一个的至少一部分设置在相应的隔离结构之间；以及功能层的叠层，至少位于所述多个第一电极之上，所述叠层至少包括位于所述多个第一电极上的第一功能层和在第一功能层之上的发光层，其中，所述多个隔离结构每一个的高度为小于700纳米。

Description

发光装置、其制备方法以及包括发光装置的电子设备 技术领域
本公开涉及发光装置及其制备方法，以及包括发光装置的电子设备。
背景技术
诸如发光二极管的发光装置广泛应用于照明和显示领域。在显示装置中，通常设置有用于界定像素的像素界定层(PDL)。通常，像素界定层被呈现为隔离结构(bank)的形式，用以界定像素(或子像素)，从而将像素(或子像素)分隔开。像素界定层一般制作在其上形成有有源装置(诸如，薄膜晶体管TFT)的基板(其也被称作TFT基板或像素基板)。
在现有技术的量子点发光二极管(QLED)和有机发光二极管(OLED)显示装置中，像素界定层的高度一般在1μm～2μm或更高。
然而，当通过打印法制备QLED和OLED显示装置时，用于功能层的打印墨滴在隔离结构处受毛细效应影响，干燥后会在隔离结构边缘处形成堆积，造成膜层不均匀。并且隔离结构边缘处的功能层材料的堆积可能不发光或者即使发光亮度也较低。另一方面，在通过打印法制备QLED和OLED显示装置的现有技术中，通常认为，进一步降低隔离结构的高度是不利于像素隔离的，易造成因墨水溢出的混色问题，一般通过调节墨水(例如，配方)来提高墨水平铺均匀性；或者，采用额外的工艺或特殊的技术来增强像素隔离。
本公开提供了一种新颖的发光装置，其具有提高的性能、寿命、发光均匀性、发光面积以及降低的成本等。
发明内容
根据本公开一个方面，提供了一种发光装置，包括：第一基板；多个第一电极，位于第一基板之上；多个隔离结构，位于第一基板之上并从第一基板向上延伸，所述多个电极中的每一个的至少一部分设置在相应的隔离结构之间；以及功能层的叠层，至少位于所述多个第一电极之上，所述叠层至少包括位于所述多个第一电极上的第一功能层和在第一功能层之上的发光层，其中，所述多个隔离结构每一个的高度为小于700纳米。
在一个实施例中，所述隔离结构的侧表面至少部分具有内凹的凹陷结构。
在一个实施例中，各个所述隔离结构包括第一部分和在所述第一部分下方的第二部分，所述第一部分的横向尺寸大于所述第二部分横向尺寸。
在一个实施例中，各个所述隔离结构的横截面为基本倒梯形，所述倒梯形的隔离结构的侧表面与所述第一基板的夹角为30-85°。
在一个实施例中，所述隔离结构的第一部分在所述侧表面处具有尖锐部。
在一个实施例中，所述隔离结构的顶面基本平坦，且顶面的高度大于所述第一功能层的高度。
在一个实施例中，所述功能层的叠层包括：位于所述多个第一电极上的多个第一部分，以及位于所述多个隔离结构的顶面上的多个第二部分，其中所述功能层的叠层的各个所述第一部分是非连续的。
在一个实施例中，所述第一功能层包括：分别位于所述多个第一电极上的多个第一部分，以及位于所述多个隔离结构的顶面上的多个第二部分，其中所述下部功能层的各个所述第一部分和对应的所述第二部分是非连续的。
在一个实施例中，所述叠层还包括位于所述发光层之上的第二功能层，所述发光装置还包括：位于所述叠层之上的第二电极。
在一个实施例中，所述发光层的所述多个单元是通过打印的墨滴层干燥之后形成的，所述墨滴含有量子点材料。
在一个实施例中，所述多个隔离结构由有机或无机绝缘材料形成。
在一个实施例中，所述多个隔离结构每一个的高度被配置为在这样的范围之内：不高于所述功能层的叠层的高度与200纳米之和，且不低于紧邻所述隔离结构的所述叠层中所述第一功能层的高度。
根据本公开一个方面，还提供了一种发光装置的制备方法，包括：提供第一基板；在所述第一基板上形成隔离结构材料层；以及对所述隔离结构材料层进行蚀刻，以在所述第一基板上形成多个隔离结构，其中，所述多个隔离结构每一个包括第一部分和在所述第一部分下方的第二部分，所述第一部分的横向尺寸大于所述第二部分的横向尺寸，其中，所述多个隔离结构每一个的高度为小于700纳米。
在一个实施例中，对所述隔离结构材料层进行蚀刻以在所述第一基板上形成多个隔离结构包括：在所述隔离结构材料层上形成图案化的掩模；使所述第一基板和要用于对所述隔离结构材料层进行蚀刻的离子或等离子流的方向成一定角度；在保持所述角度的情况下，在使所述第一基板旋转的同时，利用所述离子流对所述隔离结构材料层进行蚀刻，以形成所述多个隔离结构。
在一个实施例中，对所述隔离结构材料层进行蚀刻以在所述第一基板上形成多个隔离结构包括：在所述隔离结构材料层上形成图案化的掩模；利用各向同性的蚀刻剂对所述隔离结构材料层进行蚀刻，以形成所述多个隔离结构。
在一个实施例中，所述多个隔离结构各自在其侧表面处形成有内凹的凹陷结构。
在一个实施例中，所述第一基板还包括形成在其上的多个第一电极，所述多个隔离结构被形成为使得所述多个第一电极分别位于相应的隔离结构之间，所述方法还包括：形成功能层的叠层，包括：形成第一功能层，所述第一功能层包括位于所述多个第一电极上的多个第一部分，其中所述第一功能层的所述多个第一部分是非连续的；形成发光层，所述发光层位于所述第一功能层之上；以及形成第二功能层，所述第二功能层至少位于所述发光层之上；以及形成位于所述功能层 的叠层之上的第二电极。
在一个实施例中，形成发光层包括：通过墨滴打印并干燥来形成所述发光层的多个单元，所述墨滴含有量子点材料，所述多个单元与所述多个第一电极对应地设置。
在一个实施例中，所述多个隔离结构每一个的高度被配置为在这样的范围内：不高于所述功能层的叠层的高度与200纳米之和，且不低于紧邻所述隔离结构的所述叠层中所述第一功能层的高度。
在一个实施例中，各个所述隔离结构的横截面为基本倒梯形，所述倒梯形的隔离结构的侧表面与所述第一基板的夹角为30-85°。
在一个实施例中，各个所述隔离结构的第一部分在所述侧表面处具有尖锐部。
根据本公开一个方面，还提供了一种电子设备，包括根据本公开任意实施例或实施方式所述的发光装置。
本公开的发光装置可以被实现为显示装置或照明装置。
通过以下参照附图对本公开的示例性实施例的详细描述，本公开的其它特征及其优点将会变得清楚。
附图说明
构成说明书的一部分的附图描述了本公开的实施例，并且连同说明书一起用于解释本公开的原理。
参照附图，根据下面的详细描述，可以更加清楚地理解本公开，其中：
图1示出了现有技术中的发光装置的示意图；
图2A-2C示出了根据本公开一些实施例的发光装置的示意图；
图3A和3B示出了根据本公开另一些实施例的发光装置的示意图；
图4A和4B示出了根据本公开另一些实施例的发光装置的示意图；
图5示出了根据本公开另一实施例的发光装置的示意图；
图6示出了根据本公开另一实施例的发光装置的示意图；
图7A-7D示出了根据本公开一个实施例的发光装置的制造方法的示意图；
图8示出了根据本公开一个实施例的发光装置的制备方法的示意图；
图9示出了根据本公开另一实施例的发光装置的示意图；
图10A和10B示出了根据本公开实例1的QLED发光装置的显微照片和台阶仪测量结果；
图11A-11D分别示出了根据本公开实例1的单色和彩色QLED发光装置的显微照片；
图12示出了作为对比例2的QLED发光装置的显微照片；
图13示出了根据本公开实例2的QLED的台阶仪测量结果；
图14示出了根据本公开实例3的QLED的台阶仪测量结果；
图15示出了根据对比例3的QLED的台阶仪测量结果；
图16A-16C示出了根据本公开一个实施例的打印的发光层的单元与下部电极的关系的示意图；
图17A和17B示出根据本公开另一个实施例的打印的发光层的单元与下部电极的关系的示意图。
注意，在以下说明的实现方式中，有时在不同的附图之间共同使用同一附图标记来表示相同部分或具有相同功能的部分，而省略其重复说明。在本说明书中，使用相似的标号和字母表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步讨论。
为了便于理解，在附图等中所示的各结构的位置、尺寸及范围等有时不表示实际的位置、尺寸及范围等。因此，所公开的发明并不限于附图等所公开的位置、尺寸及范围等。
具体实现方式
现在将参照附图来详细描述本公开的各种示例性实施例。应注意： 除非另外具体说明，否则在这些实施例中阐述的部件和步骤的相对布置、数字表达式和数值不限制本公开的范围。另外，对于相关领域普通技术人员已知的技术、方法和设备可能不作详细讨论，但在适当情况下，所述技术、方法和设备应当被视为授权说明书的一部分。
应理解，以下对至少一个示例性实施例的描述仅仅是说明性的，并非是对本公开及其应用或使用的任何限制。还应理解，在此示例性描述的任意实现方式并不必然表示其比其它实现方式优选的或有利的。本公开不受在上述技术领域、背景技术、发明内容或具体实现方式中所给出的任何所表述的或所暗示的理论所限定。
另外，仅仅为了参考的目的，还可以在下面描述中使用某种术语，并且因而并非意图限定。例如，除非上下文明确指出，否则涉及结构或元件的词语“第一”、“第二”和其它此类数字词语并没有暗示顺序或次序。在本公开的上下文中，当描述A在B“之上”或“之下”时，意图涵盖A和B直接接触的情况以及A和B之间可以存在其他实体的情况。
还应理解，“包括/包含”一词在本文中使用时，说明存在所指出的特征、整体、步骤、操作、单元和/或组件，但是并不排除存在或增加一个或多个其它特征、整体、步骤、操作、单元和/或组件以及/或者它们的组合。
在现有技术的发光装置(诸如显示装置)中，用作像素界定层的隔离结构(bank)的高度一般在数微米(μm)。当诸如发光层等的功能层是通过喷墨打印(inkjet printing)的方法制备时，墨滴在隔离结构处受毛细效应影响，干燥后会在隔离结构边缘处形成堆积，造成膜层不均匀。并且隔离结构边缘处的功能层材料的堆积可能不发光或者即使发光亮度也较低，从而降低了有效发光面积，还影响了发光均匀性。此外，由于膜层的均匀性受隔离结构影响难以做到均匀平整，特别是要做多层薄膜的情况下。
另一方面，器件功能层的膜层总厚度通常为几百纳米(例如， 100nm～200nm，上部电极往往较薄(典型地，为几十纳米，例如20nm)，从而与微米量级高度的隔离结构间存在较大的高度差，使得电极搭接稳定性差。因此，现有技术中，使用相同的材料和结构，通过打印方法制备的显示装置性能往往远低于通过平面旋涂方法制备的显示装置。
图1示出了现有技术中的通过打印法制备发光装置的示意图。如图1所示，基板101上形成有多个电极(底电极)103以及用于限定像素区域的像素界定层(其包括多个隔离结构105)。在像素界定层所限定的像素区域打印功能层墨水，比如发光层等或包括发光层的叠层107、109和111。然而，如图1所示，打印的墨滴在隔离结构处受毛细效应影响，液滴会沿隔离结构的表面浸润，造成边缘处的膜厚比中央处的膜厚大，从而使得在干燥后材料在隔离结构边缘处形成堆积，造成膜层不均匀。
发光二极管的膜层的均匀性受隔离结构影响(毛细效应)难以做到均匀平整。并且，发光二极管可以包括多层薄膜(如空穴注入层、空穴传输层、发光层、电子传输层、电子注入层等)，因此在用打印法制备多层薄膜的情况下，更难做到膜层均匀平整。
上部电极113通常整面覆盖功能层或功能层的叠层107、109和111和隔离结构顶面，通常制作较薄。图1电极膜层总厚度通常只有几百纳米(nm)，例如在100nm–200nm的范围。而隔离结构的高度通常达数微米。因此隔离结构和功能层的叠层的总厚度的高度差很大，造成上部电极在隔离结构处搭接稳定性差，且易于造成上部电极断裂，如图1中的121所指示的。
因此，现有技术中使用相同的材料和结构，通过打印法制备的发光装置的性能远低于平面旋涂法制备的发光装置。
另一方面，在通过打印法制备QLED和OLED显示装置的现有技术中，通常认为，进一步降低隔离结构的高度是不利于像素隔离的，一般通过调节墨水(例如，配方)来提高墨水平铺均匀性；或者，采用额外的工艺或特殊的技术来增强像素隔离。
另一方面，像素分辨率(ppi)越大，单个子像素的开口面积越小，隔离结构的高度就不能很小，否则将可能无法打印。举例来说，假设300ppi的被动矩阵(PM)器件(不考虑TFT占据面积)，一个像素大小就是84.66μm，假设这一个像素有四个子像素，并假设子像素间隔是10μm，那留给子像素的面积就是32μm*32μm，此时如果隔离结构的高度是1000nm，那么单个子像素容积＝32*32*1μm 3，约1皮升；假设隔离结构高度是1.5μm，此时单个子像素的容积就会变成约1.5皮升；假设喷头是1皮升的，显然前者难以打印，有溢出混色的风险。
本公开至少针对上述问题中的一个或多个，提供了一种新颖的发光装置，其具有改善的发光均匀性、发光面积、性能、寿命等。
下面结合附图来具体说明根据本公开的实施例。
图2A示出了根据本公开一个实施例的发光装置的示意图。如图2A所示，发光装置200A包括第一基板101。第一基板101可以是透光或不透光的基板，可以是刚性的或柔性的基板；本公开对此没有限制。
第一基板101上形成有多个第一电极103以及多个隔离结构105。隔离结构105可以用作界定像素的像素界定层(PDL)。隔离结构105位于第一基板101上，并从第一基板向上延伸。隔离结构105可以由无机或有机材料形成。所述无机材料例如但不限于氮化硅。所述有机材料可以是例如包括聚酰亚胺树脂的光刻胶。
这里，第一电极103也可被称为底电极。第一电极103可以设置在相应的隔离结构之间。在图2A的截面图所示的示例中，仅示出了一个第一电极103，其设置在相应的两个隔离结构105之间。在某些实施例中，隔离结构105的一部分可以与第一电极103重叠。如图2A所示，第一电极103的至少一部分设置在相应的隔离结构之间。
这里还应理解，图2A仅仅示出了发光装置的一部分的截面图，因此其基板101和隔离结构105等部件可以并不全部示出。例如，当隔离结构的未示出的一侧不与功能层相邻时，对于该侧的侧表面没有特 别限制。
在本公开的实施例中，隔离结构105被配置为其高度(H)小于700nm。本申请的发明人研究发现，通过将隔离结构的高度设置为700nm或更小，可以减少功能层在隔离结构处因毛细效应引起的边缘处堆积而造成的膜层不均匀，从而可以改善膜层的均匀性。另外，通过将隔离结构的高度设置为700nm或更小，可以降低隔离结构和功能层的叠层的厚度台阶差，从而可以改善上部电极的搭接，减少断裂。
优选地，隔离结构的高度为小于等于500nm，更优选小于等于400nm，更优选在大于50nm至200nm的范围。当隔离结构的高度在200nm更低时，像素的功能层边缘可以做到无堆积。此外，当隔离结构的高度在200nm更低时，能够彻底避免上部电极(其厚度较薄)的搭接稳定性差的问题。
优选地，隔离结构的高度不高于超出要形成的功能层的叠层(即，在形成用于像素或发光单元的第二电极(上部电极或顶电极(图5，501)之前的所有功能层的叠层)的高度200nm，不低于紧邻第一电极(下部电极或底电极103)的第一层功能层的高度(通常其是空穴注入层或空穴传输层)。更优选地，所述多个隔离结构每一个的高度被配置为在这样的范围内：不高于所述功能层的叠层的高度与100纳米(nm)之和，且不低于紧邻所述叠层中紧邻所述第一电极的功能层的高度。这里，所述高度之比较是相对于共同的参照物而言地，一般地，是相对于第一基板的表面而言的。由于打印的墨水在平铺的时候厚度往往为数微米，降低的隔离结构对墨水的流动影响比较小，从而可以减少或消除了功能层边缘处的堆叠，进而增大了像素的有效发光面积。
图2B示出了根据该实施例的发光装置的部分部件的局部的放大示意图，不同于图2A，图2B中示出了一个完整的隔离结构105。如图2A和2B所示，根据本公开的实施例，隔离结构105包括第一部分和在第一部分下方的第二部分，第一部分的横向尺寸(L)大于所述第二部分的横向尺寸(l)。这里，横向是指与基板的表面基本平行的方向，也即图中所示的基本水平的方向。本领域技术人员容易理解，图 2A和2B等图中所示的截面是横贯像素(或子像素)的隔离结构和发光区的截面。
在该示例中，隔离结构被示出为基本倒梯形或类似倒梯形的形状；优选地，所述倒梯形的隔离结构的侧表面与第一基板的夹角为30-85°。但应理解，隔离结构可以多种其他形状，例如，其也可以是半梯形，或下部相对于上部凹缩的其他形状，或后面将说明的实施例中的形状，例如矩形或正梯形等等。
本申请的发明人研究还发现，通过将隔离结构的第一部分的横向尺寸(L)设置为大于所述第二部分的横向尺寸(l)，可以使得一个或多个功能层局部变得狭窄而增加电阻，或使得其断裂从而不连续(如图2A所示)。某些功能层(例如，空穴注入层)的横向导电性较高(方阻比较小)，因此可能会导致相邻像素发生串扰。而通过使得这样的功能层在像素之间狭窄或断开，可以减少像素间串扰的发生。
在图2A和2B所示的实施例中，隔离结构的倒梯形与垂线的夹角α可以为约5°-60°。通过将隔离结构的第一部分的横向尺寸(L)设置为大于所述第二部分的横向尺寸(l)，还可以改善毛细效应，减少功能层边缘在隔离结构处的堆积，从而改善每个像素的发光均匀性。
在一些实施方式中，隔离结构的表面可以做疏水处理，或者隔离结构本身材料就是疏水的。但应理解，本公开不限于此。
发光装置还包括功能层的叠层，所述叠层至少包括发光层。所述功能层的叠层可以包括位于所述多个第一电极上的多个第一部分，其中所述多个第一部分中的至少一层是非连续的。例如，所述功能层的叠层的多个第一部分分别属于不同的像素(或子像素)，不同的像素(或子像素)的功能层的叠层中某个或某些层是不连续的。在一些实施例中，所述功能层的叠层还可以包括位于所述隔离结构的顶面上的第二部分，其中所述功能层的叠层的所述第一部分中至少一层和所述第二部分中的对应的至少一层是非连续的。
回到图2A，发光装置200A还包括功能层201。作为示例，功能层201可以是例如空穴注入层(HIL)，然而本公开不限于此。功能 层201形成在第一电极103和隔离结构105上。功能层201通常可以整面地涂覆在基板上。而在图2A所示的实施例中，由于隔离结构的第一部分的横向尺寸(L)设置为大于所述第二部分的横向尺寸(l)，功能层201的墨水被隔离结构105截断而发生层断裂。功能层201的位于第一电极103上的第一部分201_1与位于隔离结构的顶面上的第二部分201_2断裂开。如此，可以避免由于功能层201的横向导电而引起的像素间串扰。需要说明的是，位于所述隔离结构的顶面上的第二部分并不对发光器件产生实际作用。
在一些实施例中，隔离结构105的顶面基本平坦。优选地，隔离结构105的顶面的高度大于功能层201的高度。在其他实施例中，隔离结构105的顶面可以是非平面的。
图2C示出了根据本公开一个实施例的发光装置。相比图2A所示的发光装置200A，图2C所示的发光装置200C还可以包括在功能层201之上的另外的功能层203。作为示例，功能层203可以是例如，空穴传输层。发光装置200C还可以包括：在功能层203之上的发光层205，以及在发光层205之上的功能层207。在一些实施例中，发光层205可以是包含量子点材料的发光层。发光层可以通过打印的墨滴干燥之后形成的，所述墨滴含有量子点材料。如此可以形成量子点显示装置。在其他实施例中，发光层也可以通过例如旋涂法形成。功能层207可以是例如电子传输层、电子阻挡层、电子注入层等中的一层或多层。如此，形成了功能层的叠层(未标示)。应理解，上述的各功能层的例子仅仅是示例性的，而非限制性的。
这里，需要说明的是，在图2C所示的实施例中，功能层203被示出其上表面基本平坦，也就是说其基本填充了功能层201的第一部分201_1和第二部分201_2之间的高度差。功能层203的该配置可以通过设置隔离结构105的高度、功能层201和203各自的配方以及所配置的溶液的性质、膜层厚度等来实现。该配置实现了基本平坦的表面，有利于后续功能层的制备。然而应理解，在其他实施例中，可以采用其他不同的配置，如下面的实施例中将进一步说明的。
本领域技术人员还将容易理解，发光层下部的下部功能层(即第一功能层)或上部的上部功能层(即第二功能层)中的一个或多个是可选的。另外，尽管在图2A和2C中下部功能层被示出为两层，但其也可能和上部功能层109被示出为单层，但其可以是多层。
这里，功能层具有本领域中的一般含义。作为示例性的描述，功能层可以意指：用于发光单元的、设置在发光单元的两个电极之间的层。功能层可以包括下列中的至少一个：空穴注入层、空穴传输层、电子注入层、电子传输层、电子阻挡层、和/或缓冲层等等。在一些实现方式中，电极或功能层可以为两个像素共享。
图3A和3B示出了根据本公开一些实施例的发光装置的示意图。图3A所示的发光装置300A具有与图2C所示的发光装置200C基本相同的部件，对于相同的部件使用相同的附图标记来表示，并省略对其重复说明。图3A所示的发光装置300A与图2C所示的发光装置200C的不同之处在于：功能层203的上表面并非是平坦的，而是形成有凹陷。在本实施例中，在功能层203之后形成的发光层205填充了该凹陷，并具有基本平坦的上表面。
图3B所示的发光装置300B具有与图3A所示的发光装置300A基本相同的部件，对于相同的部件使用相同的附图标记来表示，并省略对其重复说明。在本实施例中，在功能层203之后形成的发光层205也填充了功能层203的上表面的凹陷。图3B所示的发光装置300B与图3A所示的发光装置300A的不同之处在于：发光层205并未完全覆盖功能层203的图中所示的全部上表面。在一些实施例中，用于形成发光层205的打印的墨滴在干燥后可能仅形成在功能层203的一部分表面上。优选地，发光层205与第一电极103对应地设置；另外，优选地，发光层205在基板101上的正投影覆盖对应的第一电极103在基板101上的正投影。如此，可以保证发光层205对第一电极103的覆盖，从而改善器件发光。
另外，如图3B所示，在该示例中，上部功能层207与下部功能层 (例如，203)的未被发光层205覆盖的部分直接接触。本申请的发明人研究发现，在大多数的情况下，发光层之上的上部功能层和下部功能层的直接接触对于器件性能没有显著的影响，这是因为下部功能层和上部功能层的导电性一般都不高，因此电位的横向扩展有限，而导电性相对高的空穴注入层则优选如图中所示处于断裂状态。而即使考虑上部功能层和下部功能层的直接接触对于器件性能的影响，也可以通过选择适当的下部功能层的材料来降低或消除其影响。
图4A和4B示出了根据本公开一些实施例的发光装置的示意图。如图4A所示，发光装置400A包括第一基板101。第一基板101上形成有多个第一电极103以及多个隔离结构105。隔离结构105可以用作界定像素的像素界定层(PDL)。隔离结构105位于第一基板101上，并从第一基板向上延伸。电极103的至少一部分可以设置在相应的隔离结构之间。隔离结构105被配置为其第一部分的横向尺寸(L)设置为大于第一部分下方的第二部分的横向尺寸(l)。发光装置400A还包括功能层201。作为示例，功能层201可以是例如空穴注入层(HIL)。功能层201形成在第一电极103和隔离结构105上。功能层201的位于第一电极103上的第一部分201_1与位于隔离结构的顶面上的第二部分201_2断裂开。
发光装置400A还可以包括在功能层201之上的另外的功能层203。不同于图2C，发光装置400A中，功能层203也发生了断裂。功能层203包括位于第一电极103上方的第一部分203_1和位于隔离结构的顶面上方的第二部分203_2，二者彼此分离而不是连续的。作为示例，功能层203可以是例如，空穴传输层。
图4B示出了根据另一实施例的发光装置的示意图。相比图4A所示的装置400A，图4B所示的发光装置400B还可以包括：在功能层203之上的发光层205，以及在发光层205之上的功能层207。在一些实施例中，发光层205可以是包含量子点材料的发光层。发光层可以通过打印的墨滴干燥之后形成的，所述墨滴含有量子点材料。如此可 以形成量子点显示装置。在本实施例中，发光层205的至少一部分通过打印法打印在由隔离结构105限定的区域内。在不同的实现方式中，发光层205也可能超出所述堆叠所形成的空间的边界。
在图4B所示的实施例中，上部功能层207基本填充了所述堆叠所形成的空间中的凹陷(如果发光层205未能完全填充该空间的话)。功能层207的该配置可以通过设置隔离结构105的高度、功能层201和203、发光层205各自的配方、所配置的溶液的性质、膜层厚度等来实现。该配置实现了基本平坦的表面，有利于后续电极(第二电极)的制备。
应理解，在图4A和4B中，对于与图2A-3B所示的相同或相应的部件采用相同的附图标记来表示。因此，上面就各部件进行的说明可以同样地或适应性地应用于此，而不再对其进行详细的重复说明。
图5示出了根据本公开另一实施例的发光装置的示意图。相比图2C所示的实施例，图5所示的发光装置500还包括在功能层的叠层(未标以附图标记)上的第二电极(上部电极)501。根据需要，在一些实现方式中，第二电极501可以是整面电极(或者，毯式电极)，其可以覆盖多个像素的功能层。然而，本公开并不限于此。在一些实现方式中，第二电极501可以被配置为允许发光层所发出的光从其透射出去，例如第二电极501可以由ITO或薄的MgAg合金等透光材料形成。示例性地，第二电极501的厚度可以为几百纳米，例如100nm-200nm。
发光层205、对应的第一电极103和第二电极501的对应的部分可以被包括在对应的像素中。对应的第一电极103、功能层的叠层中的对应部分、以及第二电极501的对应的部分共同构成发光单元(或称为发光器件)。一般地，像素可以包括一个或多个发光单元。像素也可以包括多个子像素，每个子像素具有发光单元。例如，像素可以包括红绿蓝(RGB)三个发光单元(其也可以被称为子像素)。还需要说明的是，本申请中所称术语像素，在没有相反说明或者上下文给 出相反的含义的情况下，其可以表示像素或子像素。
在某些实施例中，发光装置500还可以包括设置在第二电极501之上覆盖层503。覆盖层配置为允许从第二电极透射的光通过，覆盖层可以提高器件出光效率。在一些实施例中，覆盖层可以由高折光指数(n)材料构成，一般n大于1.65，优选大于1.8。覆盖层的厚度可以在几十纳米至几千纳米的范围。
在不同的实现方式中，根据本公开发光装置可以是通过第一电极和第一基板出光的底发光型发光装置、通过第二电极出光的顶发光型发光装置、或通过两者出光的双面发光型发光装置。
尽管这里基于图2A和图2C所示的实施例进一步示出了上部电极501，然而本领域技术人员根据本公开的教导将知晓，可以同样地或类似地在其他实施例中形成上部电极501。这里不再进行具体说明。
图6示出了根据本公开另一实施例的发光装置的示意图。如图6所示，发光装置600包括第一基板101。第一基板101上形成有多个第一电极103以及多个隔离结构105。隔离结构105可以用作界定像素的像素界定层(PDL)。隔离结构105位于第一基板101上，并从第一基板向上延伸。电极103的至少一部分可以设置在相应的隔离结构之间。
发光装置600的隔离结构105被配置为不同于图2A-图5所示的隔离结构。在该实施例中，虽然隔离结构105被同样配置为其第一部分的横向尺寸设置为大于第一部分下方的第二部分的横向尺寸，但这是通过在隔离结构105的侧表面(或侧壁)上形成内凹的凹陷611实现的。凹陷611可以通过例如湿法蚀刻或干法蚀刻来实现。
发光装置600还包括功能层601。作为示例，功能层601可以是例如空穴注入层(HIL)。功能层601形成在第一电极103和隔离结构105上。功能层601的位于第一电极103上的第一部分601_1与位于隔离结构的顶面上的第二部分601_2断裂开。
在该示例中，如图所示，在隔离结构105之间形成了开口。该开口的空间的上表面大于底面。如此可以促进功能层601的断裂，从而可以进一步降低串扰。
之后，本领域技术人员将容易理解，可以同样地或类似地形成各种功能层(包括发光层)和上部电极，因此，这里不再进行详细说明。
这里，需要说明的是，一方面，在一些实施例中，在隔离结构的侧表面形成凹陷本身就可以使得隔离结构具有第一部分和在所述第一部分下方的第二部分，所述第一部分的横向尺寸大于所述第二部分的横向尺寸。另一方面，在例如前述图2A-图5所示的实施例中，还可以在第一部分的横向尺寸大于所述第二部分的横向尺寸的隔离结构(例如，倒梯形或半倒梯形)的侧表面进一步形成凹陷，从而可以进一步促进后续形成的期望的功能层的断裂。
优选地，可以在隔离结构的与要形成的功能层的叠层相邻的侧表面处形成尖锐部，以截断打印或涂覆到基板上的用于形成功能层的液体，从而使得所形成的功能层(例如，下部功能层)不连续。通过使得隔离结构的第一部分的横向尺寸大于所述第二部分的横向尺寸或通过使得隔离结构的侧表面形成凹陷，即可以形成该尖锐部。优选地，该尖锐部被形成为在隔离结构的侧表面尽可能靠上，例如形成在隔离结构的所述侧表面的上部，其截断流体的效果将由于形成在所述侧表面的下部。
在其他实施例中，通过在该侧表面形成凹陷也可以使得所形成的功能层不连续；类似地，优选凹陷在该侧表面的上部。
图7A-7D示出了根据本公开一个实施例的发光装置的制造方法的示意图。
如图7A所示，提供第一基板101，其上形成有第一电极103。在第一基板101上形成隔离结构材料层701。隔离结构材料层701覆盖第一基板101和第一电极103。作为示例，隔离结构材料层701可以由氮化硅(Si 3N 4)形成；然而，本公开不限于此。隔离结构材料层的 高度可以根据要形成的隔离结构的高度来设定，优选地，隔离结构材料层的高度为小于700纳米。
之后，在所述隔离结构材料层上形成图案化的掩模703。掩模703可以由光刻胶形成，或者也可以由硬掩模材料形成。
之后，如图7B所示，使所述第一基板101和要用于对隔离结构材料层701进行蚀刻的离子或等离子流707的方向成一定角度。例如，在图7B所示的实施例中可以将其上形成了掩模图案的第一基板101放置在承载台(未示出)上卡扣就位，使其相对于旋转轴705倾斜成一定角度β，也即相对于水平方向倾斜90°-β。例如，可以使第一基板101相对于水平方向倾斜小于等于30度的角度。而用于蚀刻的离子或等离子的射流707方向基本与旋转轴的方向对准。在保持所述角度的情况下，在使第一基板101绕旋转轴705旋转的同时，利用所述离子流对所述隔离结构材料层进行蚀刻。作为示例，旋转速率为每分钟一转。
当第一基板101绕旋转轴705旋转到如图7C的左侧的图所示的位置时，离子流或等离子流对隔离结构材料层的蚀刻如该左侧的图所示，左侧剩余的隔离结构材料层成倒梯形，而右侧剩余的隔离结构材料层成梯形。这是因为蚀刻的方向(即，离子流或等离子流的方向)相对于基板(或者说隔离结构材料层)成角度。
而当第一基板101绕旋转轴705旋转到如图7C的右侧的图所示的位置时，离子流或等离子流对隔离结构材料层的蚀刻如该右侧的图所示，右侧剩余的隔离结构材料层成倒梯形，而左侧剩余的隔离结构材料层成梯形。这是因为蚀刻的方向(即，离子流或等离子流的方向)相对于基板(或者说隔离结构材料层)成角度。
如此，基板保持旋转，从而在左右两侧都形成了具有倒梯形截面的多个隔离结构，如图7D所示。注意，这里仅仅示出了至少部分的隔离结构作为示意。
在另一实施例中，也可以将基板设置为基本水平(或与旋转轴垂直)，而调整蚀刻所用离子或等离子流的方向相对于旋转轴的角度， 来形成隔离结构。
在其他实施例中，可以在形成图案化的掩模703之后，利用各向同性的蚀刻剂对隔离结构材料层进行刻蚀，来形成多个隔离结构，如图6所示。所述各向同性的蚀刻剂可以根据隔离结构材料和第一电极的材料来选择，以使得其蚀刻对隔离结构材料呈蚀刻选择性。
图8示出了根据本公开一些实施例的发光装置的制备方法的示意流程图。
如图8所示，在步骤S801，提供第一基板，例如，如前面的实施例中所描述的基板101。第一基板上可以形成有多个下部电极(第一电极)。
在步骤S803，在所述第一基板上形成隔离结构材料层。作为非限制性的示例，隔离结构材料层可以通过化学气相沉积(CVD)利用氮化硅形成。
之后，在步骤S805，形成隔离结构。在一个实现方式中，在步骤S8051，在隔离结构材料层上形成图案化的掩模。在步骤S8053，使所述第一基板和要用于对所述隔离结构材料层进行蚀刻的离子或等离子流的方向成一定角度。在步骤S8055，各向异性的干法蚀刻。例如，可以在保持所述角度的情况下，在使所述第一基板旋转的同时，利用离子或等离子流对所述隔离结构材料层进行蚀刻。在另一实现方式中，可以在隔离结构材料层上形成图案化的掩模之后，在步骤S8057，进行各向同性的湿法蚀刻。从而，形成多个隔离结构。所形成的隔离结构每一个都包括第一部分和在所述第一部分下方的第二部分，第一部分的横向尺寸大于所述第二部分的尺寸。
在一些实施方式中，所述多个隔离结构每一个的高度被配置为小于700纳米(nm)。在一些实施方式中，所述多个隔离结构每一个的高度被配置为在这样的范围内：不高于所述功能层的叠层的高度与200纳米(nm)之和，且不低于紧邻所述叠层中紧邻所述第一电极的功能层的高度。
作为示例，可以采用Si 3N 4或SiO 2来形成隔离结构材料层，并利用CF 4等离子气来进行刻蚀。在一个示例中，Si 3N 4隔离结构材料层的厚度为100nm，基板相对于水平的倾斜角度为约30°，基板旋转速率被设置为每分钟一转。在约10mTorr的压力下，电源功率为约25kW，偏置功率为约25kW，以流速为约800sccm的CF 4气体和约1000sccm的O 2气体的混合气，对Si 3N 4隔离结构材料层进行蚀刻。
在一些实施例中，所述多个隔离结构各自在其侧表面处形成有内凹的凹陷结构。例如，可以通过湿法蚀刻来形成所述凹陷结构。
之后，形成功能层的叠层。功能层的叠层可以与下部电极对应地设置。在一个实现方式中，在步骤S807，形成下部功能层。所述下部功能层包括位于所述多个第一电极上的第一部分，以及位于所述多个隔离结构的顶面上的第二部分，其中所述下部功能层的所述第一部分和所述第二部分是非连续的。下部功能层可以是单层或多层。下部功能可以包括空穴注入层和空穴传输层等中的一个或多个。在一些实现方式中，可以如下制备空穴注入层：将空穴注入材料配成适合涂布的墨水配方，选择合适的涂布参数，进行涂布，涂布后将基板放置在热板上，进行干燥。可以如下制备空穴传输层：将空穴传输层材料的配成可以打印的配方，进行打印；然后将基板转移至真空热板，进行干燥。应理解，这里所描述的制备下部功能层的方法进行是示例性的而非限制性的；本领域技术人员将理解可以采用多种多样的方法来制备功能层。在一些实现方式中，空穴注入层(HIL)的厚度可以在几十至几百纳米的范围，例如20nm–300nm，优选30nm-150nm；空穴传输层(HTL)的厚度可以在几十至几百纳米的范围，例如10nm–200nm，优选15nm–100nm。
在步骤S809，形成发光层，所述发光层位于所述下部功能层之上。在一些实施方式中，通过喷墨打印并干燥来形成所述发光层的多个单元，所述墨滴含有量子点材料。所述多个单元可以与所述多个第一电极对应地设置。在一些实现方式中，可以如下来制备量子点(QD)发光层：将QD原液通过离心沉淀后，重新分散到打印溶剂的配方配成 可以打印的墨水，装入打印设备；根据设置的打印参数，将QD墨水精准打印在像素基板的相互独立的电极区域，并将相应的底电极区域完全覆盖；之后将基板转移至真空热板，进行干燥。在一些实现方式中，QD发光层的厚度可以在几十至几百纳米的范围，例如10nm–100nm，优选15nm-60nm。
在步骤S811，形成上部功能层，所述上部功能层至少位于所述发光层之上。应理解，上部功能层可以是单层或多层。作为示例，上述功能层可以包括电子传输层和/或电子注入层，其厚度各自可以在几十至几百纳米的范围，例如10nm–400nm，优选20nm-100nm。
之后，在步骤S813，形成位于所述功能层的叠层之上的第二电极。在一些实现方式中，第二电极可以被配置为整面地形成，覆盖一个或多个像素(或子像素)的显示区域。可选地，如果从第二电极提取光的话，可以在所述第二电极上形成可以透射光的覆盖层。
图9示出了根据本公开另一实施例的发光装置的示意图。如图9所示，发光装置900可以包括第一基板901和对置的第二基板905。第一基板901上可以形成有多个像素903。像素903或者至少其发光单元可以是根据本公开前述实施例制备的像素或发光单元。在第二基板905上形成有多个间隔物907。第一基板901和第二基板905通过封装料911进行包封，在第一基板901和第二基板905之间可以填充有填充剂909。尽管这里间隔物907被示出为梯形的界面，然而这仅仅是示例性的，本公开不限于此，而是可以采用任何适当的形状。这里，作为示例，间隔物907可以通过打印法制备，比如，可以通过在期望的位置多次打印墨滴并干燥，从而形成间隔物907。或者，间隔物907也可以通过沉积间隔物材料(例如，有机或无机绝缘材料)并对其进行图案化(例如，通过利用掩模的蚀刻)来获得。间隔物的密度和排布与像素设计与排布有关，可以低于像素分辨率PPI。
图16A-16C示出了根据本公开一个实施例的打印的发光层的单元 与下部电极(也被称作底电极)的关系的示意俯视图。为了图示和说明的方便，在图16A-16C以及下面的图17A和17B中，未示出隔离结构。在该示例中，下部电极103被示出为圆形。发光层的单元205也被示出为圆形。在俯视图中，发光层的单元205覆盖下部电极(即，第一电极)103。也就是说，发光层的单元205在第一基板101上的正投影覆盖对应的第一电极103在第一基板上的正投影。这里，本领域技术人员容易理解，实际墨滴干燥后的形状一般可能接近圆形，但难以实现完美的圆形，这里以圆形作为示例进行理论推算。而在实际应用中，本领域技术人员可以根据本申请所教导的原理容易地根据实际需要进行计算。
在一些实施例中，通过墨滴打印的方法制作发光层，在这种情况下，墨滴打印所形成的单元优选覆盖下部电极。如图16A所示，假设墨滴干燥后所形成的圆形单元205的半径(可以被视为横向尺寸(直径)的一半)为R，下部电极103的半径为r，打印的精度(例如，墨滴落点的偏差)为a。假设在理想情况下，打印的墨滴干燥后所形成的圆形单元205的中心与圆形的下部电极103重合(对准)。这里，需要说明的是，打印设备的喷嘴对准下部电极可以通过是设备自带功能(例如，CCD相机自动对位)来实现，落点精度由打印设备决定。
则考虑到打印的精度(例如，墨滴落点的偏差)a，墨滴干燥后所形成的圆形单元205的半径R应当大于或等于下部电极103的半径r与打印精度(例如，打印落点误差)a之和，也即，R≥r+a。从而，可以确保在打印精度a的条件下，所打印形成的发光层的单元205亦能够完全覆盖下部电极103。
在无显著漏电情况下，一般地，仅所打印的发光层中的与下部电极重叠的部分会发光。
图16B示出了发光层的相邻的两个单元205和对应的相邻的两个下部电极103。如图16B中所示，两个单元205的半径分别为R1和R2，打印精度分别为a1和a2，两个下部电极103的半径分别为r1和r2。其分别满足上述的条件，也即R1≥r1+a1，R2≥r2+a2。
相邻的两个下部电极103之间的中心距d被配置为大于或等于两个单元205的半径R1、R2与打印精度a1、a2之和。也即，d≥R1+R2+a1+a2。在R1＝R2＝R、r1＝r2＝r且a1＝a2＝a的情况下，间距d≥2R+2a≥2r+4a。
应当理解，对于墨滴干燥后膜层的尺寸和下部电极的尺寸及间距的设定，可以根据不同的显示分辨率、不同的像素设计(例如，几何形状和大小不同)、是否允许部分重叠设计、设备精度等来考虑。
作为示例性的例子，可以考虑下面的情况。设定初始条件：150ppi分辨率，形成4个等大圆形下部电极(1红、1绿、2蓝)，打印设备精度为10微米，如图16C所示。对应正方形像素边长为可以169微米(25400微米/150)，下部电极间距是边长一半169/2＝84.5微米。由于2R+2a≤d即R≤(d-2a)/2＝(84.5-2*10)/2＝32.25微米，即墨滴干燥后所形成的单元的半径最大为32.25微米。同时r≤R-a＝22.25微米，即下部电极最大半径为22.25微米，对应的最大开口率为21.7％。
因此，基板分辨率和像素设计决定下部电极间距，下部电极间距和打印设备精度决定墨滴所形成的单元的直径上限，墨滴所形成的单元的直径(实验值)决定下部电极半径上限。
这里，所举例的圆形下部电极仅仅是示例性的，其开口率如前所示比较低，但其和所打印的墨滴自然干燥形状吻合，而且方便讨论下部电极间距。在实际的产品中可以应用同样的原理来配置具有所需的几何形状的单元和电极。例如，稍后将说明的实施例中采用了长方形的电极。
此外，墨滴打印所形成的单元干燥后的半径R可能受下面因素影响：墨水配方、下部电极的大小及形状。可调节墨水的配方改变其铺展半径。一般墨水的表面张力越大铺展越小，表面张力越小铺展越大。墨水的表面张力，主要依靠配方中各种溶剂的比例来调整(不同溶剂的表面张力是有差异的)。因此，可以根据实际需要，来调整使得该配方的墨滴打印出来，刚好覆盖下部电极区域的同时，不流淌到相邻子像素的下部电极区域。根据配方的不同，包含量子点材料的墨滴所 形成的单元干燥前后的直径之比可以为约1.5：1至约1.1：1。
调节墨水的固含量可以改变膜层厚度。由于在本公开的实施例中，没有像素隔离结构(无像素界定部件，诸如隔离结构(bank))，因此不能通过增减打印墨滴数来改变膜层的厚度；对此，可以通过对墨水配方本身的固含量进行精准控制，满足铺展半径需求的同时，也满足膜层厚度。
另外，还可以调节墨水的挥发速率来调节铺展半径，控制整体的挥发速率，使得墨滴内溶质在挥发性比较高的溶剂刚好即将挥发完全时，刚好铺展到所需的半径。如果还没到所需半径，有可能因为溶质在剩下的溶剂中粘度变大，无法进行移动，导致可能覆盖不全下部电极区域。如果挥发性比较高的溶剂扩到半径大小还没挥发完，可能会超过铺展所需半径，会出现干扰相邻子像素，可能导致混色现象发生。但应理解，这些并非是限定性的，在某些情况下反而可以对其进行利用。
图17A和17B示出根据本公开另一个实施例的打印的发光层的单元与下部电极的关系的示意图。在图17A和17B所示的实施例中，以长条形像素举例进行说明。
如图17A所示，墨滴(多次)打印所形成的单元205为长条形，宽度为L；下部电极对应也为长条形，宽度为l。本领域技术人员将容易理解，可以通过打印多个墨滴并干燥，来形成基本长条形或任何其他形状的发光层的单元。
假设理想情况下，墨滴打印所形成的单元205的中心线与下部电极的中心线对齐。则，类似地，为了保证覆盖，单元205被配置为其半宽度(横向尺寸的一半，L/2)大于或等于对应的下部电极103的半宽度(l/2)与打印精度(a)之和，也即，L/2≥l/2+a。
图17B示出了相邻的单元2051和2052以及对应的相邻的下部电极1031和1032的情形。各单元2051和2052各自为长条形，且在其所延伸的方向上平行。对应的下部电极1031和1032各自为长条形， 且在其所延伸的方向上平行。各单元2051和2052和对应的下部电极1031和1032满足在前述的配置，也即，单元的半宽度(L/2)大于或等于对应的下部电极的半宽度(l/2)与打印精度(a)之和。
类似地，相邻的两个下部电极1031和1032之间的中心距d被配置为大于或等于两个单元2051和2052的半宽度L1/2、L2/2与打印精度a1、a2之和。也即，d≥L1/2+L2/2+a1+a2。在L1＝L2＝L、l1＝l2＝l且a1＝a2＝a的情况下，间距d≥L+2a≥l+4a。
作为示例性的例子，设定初始条件：100ppi分辨率，红绿蓝子像素等宽等距，打印设备精度为10微米。对应正方形像素边长为254微米(25400微米/100)，下部电极间距d＝254/3＝84.7微米。墨水所形成的单元的宽度L≤d-2a＝64.7微米，下部电极宽度l≤L-2a＝64.7-20＝44.7微米。
下面说明根据本公开一些实施例制备发光装置的实例。
实例1：
首先，提供基板，该基板具有大于50nm(这里，为约55nm)的高度的矮隔离结构作为像素隔离结构。该隔离结构的横截面为倒梯形(其与水平的夹角大于等于80°且小于90°)。替代地，也可以采用横截面为矩形的隔离结构。作为示例，采用其上形成了ITO透明电极(作为下部电极)的玻璃基板。
之后，可选地，对基板进行清洗。例如，对具有像素隔离结构的基板进行溶剂清洗，吹干并经过等离子表面处理后，得到洁净的像素基板。
之后，制作空穴注入层以及空穴传输层。例如，在空气环境中，在清洁的基板上涂布PEDOT:PSS的水溶液，PEDOT是EDOT(3，4-乙烯二氧噻吩单体)的聚合物，PSS是聚苯乙烯磺酸盐。涂布完成后在空气中进行退火处理，再将其转移至氮气环境的手套箱中进行退火。从而，最终在ITO表面形成一层PEDOT:PSS层，作为空穴注入层。然后在PEDOT:PSS层上通过喷墨打印的方式，打印聚((9,9-二辛基芴 -2,7-二基)-共(4,4'-(N-(4-仲-丁基苯基)二苯胺))(TFB)的正辛苯溶液(浓度为1wt％)，打印完成后在手套箱中退火形成空穴传输层。在一些实现方式中，空穴注入层(HIL)的厚度可以在几十至几百纳米的范围，例如20nm–300nm，优选30nm-150nm；空穴传输层(HTL)的厚度可以在几十至几百纳米的范围，例如10nm–200nm，优选15nm–100nm。
之后，制作发光层。在空穴传输层上打印量子点墨水(量子点为CdZnSeS/ZnS，浓度为80mg/mL，其对应的发射波长为470nm～485nm)。然后转移到真空热板，在抽真空的环境下退火。在一些实现方式中，QD发光层的厚度可以在几十至几百纳米的范围，例如10nm–100nm，优选15nm-60nm。
之后，作为上部功能层的示例，制作氧化锌纳米晶薄膜。例如，可以在发光层上旋涂氧化锌纳米晶溶液，例如，以2500转/分钟的转速旋涂50s。旋涂完成后在手套箱中进行退火处理。最终在发光层表面形成一层氧化锌纳米晶薄膜。作为示例，上述功能层可以包括电子传输层和/或电子注入层，其厚度各自可以在几十至几百纳米的范围，例如10nm–400nm，优选20nm-100nm。
之后，制作上部电极。例如，可以将制备了氧化锌纳米晶薄膜之后所得的器件置于真空蒸镀仓内，蒸镀阴极银电极。
之后，可以将蒸镀好电极的基板，通过UV胶与盖板粘合，UV固化后完成封装以用于测试。
作为实例2-3，使用与上述实例1基本相同的条件制备基本相同的器件，区别仅在于隔离结构的高度分别为200nm和600nm。
作为对比例1，使用无隔离结构的基板(非像素基板，整面发光)，且所有功能层材料与上述实例中的一致且厚度基本相同，但使用旋涂工艺制备。
作为对比例2，提供其上形成约2.5微米高度的隔离结构和ITO电极的玻璃基板作为像素基板打印制备红、绿和蓝色器件，各对应膜 层的制备工艺与上述实例的相同，区别仅在于隔离结构的几何尺寸和形状不同。
作为对比例3，使用与上述实例基本相同的条件制备基本相同的器件，区别仅在于隔离结构的高度为1000nm。
经测量，对比例2的器件(利用高隔离结构像素基板制备的红绿蓝器件)的寿命约是对比例1的器件(旋涂非像素基板器件)的约1/5～1/10，而本公开实例1的利用矮隔离结构像素基板制备同样的红绿蓝器件寿命约是对比例1的器件(旋涂非像素基板器件)的约4/5。从而大大提高了打印QD发光装置的寿命。
图10A和10B示出了根据本公开上述实例1的QLED发光装置的显微镜照片和台阶仪测量结果。该显微镜照片和台阶仪测量结果，根据本公开的实例1的发光装置中，像素的功能层的边缘堆积消失，像素内膜厚均匀性提高。从图10A的显微镜照片看，无边缘推积现象。从图10B的台阶仪膜厚照片来看，像素内膜层均匀，也验证了无堆积的现象。
图11A-11D分别示出了根据本公开实施例或实例制备的单色和彩色QLED发光装置的显微镜照片。从图11A-11D所示的根据本公开实施例的QLED电致发光装置的显微镜照片，分别为红色、绿色、蓝色和红绿蓝点亮发光时的显微镜照片。从这些显微镜照片可以容易看出，发光均匀性都非常好。
而作为对比，图12示出了上述的对比例2的高隔离结构的QLED发光装置的RGB三色发光的显微镜照片。从该照片可以看出，对比例2的QLED发光装置的红绿蓝像素均有沿隔离结构四周的区域发光较暗。这可能是由于隔离结构高度较高以及毛细作用导致的。
图13示出了根据本公开实例2的QLED的台阶仪测量结果。在 该实例2中，与实例1的区别仅在于隔离结构的高度为200nm。如图13所示，台阶仪测量结果表明，功能层的叠层基本是平坦的，在隔离结构处的边缘没有堆积所导致的谱线翘曲。
图14示出了根据本公开实例3的QLED的台阶仪测量结果。在该实例3中，与实例1的区别仅在于隔离结构的高度为600nm。如图14所示，台阶仪测量结果表明，功能层的叠层在隔离结构处的边缘向上翘起，有大约18nm的堆积。
图15示出了根据对比例3的QLED的台阶仪测量结果。在该对比例3中，与实例1的区别仅在于隔离结构的高度为1000nm。如图15所示，台阶仪测量结果表明，功能层的叠层在隔离结构处的边缘向上翘起，有大约22nm的堆积。
考虑到功能层的叠层的总厚度，功能层的叠层在隔离结构处的边缘具有通常小于20nm的堆积是可以接受的。而当隔离结构的高度为小于或等于200nm时，功能层在隔离结构处的边缘基本没有不期望的堆积，这是优选地。当隔离结构的高度为小于或等于50nm时，由于隔离结构对打印或涂布的用于形成功能层的流体的隔离作用(包括在干燥时)减弱，虽然功能层可能平坦，但可能会造成器件的其他特性的削弱，因此需要折衷考虑或采用进一步的措施。例如，如上述实施例中所述，可以使隔离结构的侧表面形成有内凹的凹陷结构等。
根据本公开的实施例的发光装置可以被实现为显示装置，例如量子点显示装置；然而本公开不限于此。
根据本公开一个方面，还提供了一种电子设备，其可以包括如本公开的任意实施例或实现方式所述的发光装置。
本领域技术人员应当意识到，在上述实施例中描述操作(或步骤)之间的边界仅仅是说明性的。多个操作可以结合成单个操作，单个操作可以分布于附加的操作中，并且操作可以在时间上至少部分重叠地执行。而且，另选的实施例可以包括特定操作的多个实例，并且在其 他各种实施例中可以改变操作顺序。但是，其它的修改、变化和替换同样是可能的。因此，本说明书和附图应当被看作是说明性的，而非限制性的。
虽然已经通过示例对本公开的一些特定实施例进行了详细说明，但是本领域的技术人员应该理解，以上示例仅是为了进行说明，而不是为了限制本公开的范围。在此公开的各实施例可以任意组合，而不脱离本公开的精神和范围。本领域的技术人员还应理解，可以对实施例进行多种修改而不脱离本公开的范围和精神。本公开的范围由所附权利要求来限定。

Claims (22)

  1. 一种发光装置，其特征在于，包括：
    第一基板；
    多个第一电极，位于第一基板之上；
    多个隔离结构，位于第一基板之上并从第一基板向上延伸，所述多个电极中的每一个的至少一部分设置在相应的隔离结构之间；以及
    功能层的叠层，至少位于所述多个第一电极之上，所述叠层至少包括位于所述多个第一电极上的第一功能层和在第一功能层之上的发光层，
    其中，所述多个隔离结构每一个的高度为小于700纳米。
  2. 如权利要求1所述的发光装置，其特征在于，所述隔离结构的侧表面至少部分具有内凹的凹陷结构。
  3. 如权利要求1所述的发光装置，其特征在于，其中各个所述隔离结构包括第一部分和在所述第一部分下方的第二部分，所述第一部分的横向尺寸大于所述第二部分横向尺寸。
  4. 如权利要求3所述的发光装置，其特征在于，各个所述隔离结构的横截面为基本倒梯形，所述倒梯形的隔离结构的侧表面与所述第一基板的夹角为30-85°。
  5. 如权利要求3所述的发光装置，其特征在于，其中所述隔离结构的第一部分在所述侧表面处具有尖锐部。
  6. 如权利要求1所述的发光装置，其特征在于，其中所述隔离结构的顶面基本平坦，且顶面的高度大于所述第一功能层的高度。
  7. 如权利要求1所述的发光装置，其特征在于，其中所述功能层的叠层包括：位于所述多个第一电极上的多个第一部分，以及位于所述多个隔离结构的顶面上的多个第二部分，
    其中所述功能层的叠层的各个所述第一部分是非连续的。
  8. 如权利要求1所述的发光装置，其特征在于，其中所述第一功能层包括：分别位于所述多个第一电极上的多个第一部分，以及位于所述多个隔离结构的顶面上的多个第二部分，
    其中所述第一功能层的各个所述第一部分和对应的所述第二部分是非连续的。
  9. 如权利要求1所述的发光装置，其特征在于，其中所述叠层还包括位于所述发光层之上的第二功能层，
    所述发光装置还包括：
    位于所述叠层之上的第二电极。
  10. 如权利要求1所述的发光装置，其特征在于，其中所述发光层包括多个单元，所述多个单元是通过打印的墨滴层干燥之后形成的，所述墨滴含有量子点材料，
    所述发光层的所述多个单元被配置为，在俯视图上：
    对于任一单元，该单元的横向尺寸大于或等于该单元所对应的第一电极的横向尺寸与用于打印的喷嘴的打印精度的两倍之和；
    在相邻的两个单元之间，与所述相邻的两个单元所对应的两个第一电极的中心间距大于或等于该相邻的两个单元各自的横向尺寸的一半与用于打印的喷嘴的打印精度的两倍之和。
  11. 如权利要求1所述的发光装置，其特征在于，所述多个隔离结构由有机或无机绝缘材料形成。
  12. 如权利要求1所述的发光装置，其特征在于，其中所述多个隔离结构每一个的高度被配置为在这样的范围之内：不高于所述功能层的叠层的高度与200纳米之和，且不低于紧邻所述隔离结构的所述叠层中所述第一功能层的高度。
  13. 一种发光装置的制备方法，其特征在于，包括：
    提供第一基板；
    在所述第一基板上形成隔离结构材料层；以及
    对所述隔离结构材料层进行蚀刻，以在所述第一基板上形成多个隔离结构，
    其中，所述多个隔离结构每一个包括第一部分和在所述第一部分下方的第二部分，所述第一部分的横向尺寸大于所述第二部分的横向尺寸，
    其中，所述多个隔离结构每一个的高度为小于700纳米。
  14. 如权利要求13所述的方法，其特征在于，其中对所述隔离结构材料层进行蚀刻以在所述第一基板上形成多个隔离结构包括：
    在所述隔离结构材料层上形成图案化的掩模；
    使所述第一基板和要用于对所述隔离结构材料层进行蚀刻的离子或等离子流的方向成一定角度；
    在保持所述角度的情况下，在使所述第一基板旋转的同时，利用所述离子流对所述隔离结构材料层进行蚀刻，以形成所述多个隔离结构。
  15. 如权利要求13所述的方法，其特征在于，其中对所述隔离结构材料层进行蚀刻以在所述第一基板上形成多个隔离结构包括：
    在所述隔离结构材料层上形成图案化的掩模；
    利用各向同性的蚀刻剂对所述隔离结构材料层进行蚀刻，以形成 所述多个隔离结构。
  16. 如权利要求13所述的方法，其特征在于，其中所述多个隔离结构各自在其侧表面处形成有内凹的凹陷结构。
  17. 如权利要求13所述的方法，其特征在于，其中所述第一基板还包括形成在其上的多个第一电极，所述多个隔离结构被形成为使得所述多个第一电极分别位于相应的隔离结构之间，
    所述方法还包括：
    形成功能层的叠层，包括：
    形成第一功能层，所述第一功能层包括位于所述多个第一电极上的多个第一部分，其中所述第一功能层的所述多个第一部分是非连续的；
    形成发光层，所述发光层位于所述第一功能层之上；以及
    形成第二功能层，所述第二功能层至少位于所述发光层之上；以及
    形成位于所述功能层的叠层之上的第二电极。
  18. 如权利要求17所述的方法，其特征在于，其中形成发光层包括：通过墨滴打印并干燥来形成所述发光层的多个单元，所述墨滴含有量子点材料，所述多个单元与所述多个第一电极对应地设置。
  19. 如权利要求17所述的方法，其特征在于，其中所述多个隔离结构每一个的高度被配置为在这样的范围内：不高于所述功能层的叠层的高度与200纳米之和，且不低于紧邻所述隔离结构的所述叠层中所述第一功能层的高度。
  20. 如权利要求13所述的方法，其特征在于，各个所述隔离结构的横截面为基本倒梯形，所述倒梯形的隔离结构的侧表面与所述第一 基板的夹角为30-85°。
  21. 如权利要求13所述的发光装置，其特征在于，其中各个所述隔离结构的第一部分在所述侧表面处具有尖锐部。
  22. 一种电子设备，其特征在于，包括如权利要求1-12中任一项所述的发光装置。
PCT/CN2022/137281 2021-12-08 2022-12-07 发光装置、其制备方法以及包括发光装置的电子设备 WO2023104104A1 (zh)

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