WO2023125882A1 - 显示装置及制造显示装置的方法 - Google Patents

显示装置及制造显示装置的方法 Download PDF

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Publication number
WO2023125882A1
WO2023125882A1 PCT/CN2022/143686 CN2022143686W WO2023125882A1 WO 2023125882 A1 WO2023125882 A1 WO 2023125882A1 CN 2022143686 W CN2022143686 W CN 2022143686W WO 2023125882 A1 WO2023125882 A1 WO 2023125882A1
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emitting layer
sub
light emitting
light
electrode
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PCT/CN2022/143686
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English (en)
French (fr)
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高远
彭军军
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纳晶科技股份有限公司
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/80—Constructional details
    • H10K50/805—Electrodes
    • 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
    • H10K71/10—Deposition of organic active material
    • H10K71/12—Deposition of organic active material using liquid deposition, e.g. spin coating
    • H10K71/13—Deposition of organic active material using liquid deposition, e.g. spin coating using printing techniques, e.g. ink-jet printing or screen printing

Definitions

  • the present disclosure relates to a display device and a method of manufacturing the display device.
  • Light emitting devices such as light emitting diodes are widely used in lighting and display fields.
  • the display of a color image is realized by a plurality of pixels emitting colored light.
  • Each pixel may typically include at least three sub-pixels, namely a blue sub-pixel that emits blue light, a green sub-pixel that emits green light, and a red sub-pixel that emits red light.
  • OLEDs Organic Light Emitting Diodes
  • QLEDs Quantum Dot Light Emitting Diodes
  • each sub-pixel may be formed by inkjet printing.
  • a method of manufacturing a display device including:
  • a substrate is provided, on which there is a first electrode array composed of a plurality of first electrodes respectively corresponding to blue sub-pixels, green sub-pixels and red sub-pixels, the first electrode array includes a plurality of rows along a first direction and A plurality of columns along a second direction intersecting the first direction, the first electrodes in each row correspond to sub-pixels of the same color, and the first electrodes corresponding to the red sub-pixel and the green sub-pixel each contain each other along the second direction
  • the light-emitting layer of each pixel at least includes a red light-emitting layer corresponding to a red sub-pixel, a blue light-emitting layer corresponding to a blue sub-pixel, and a green light-emitting layer corresponding to a green sub-pixel, and the light-emitting layer of each pixel Among them, along the second direction, the blue light emitting layer is located between the red light emitting layer and the green light emitting layer.
  • a display device including:
  • a first electrode array located on the substrate and composed of a plurality of first electrodes respectively corresponding to blue sub-pixels, green sub-pixels and red sub-pixels, the first electrode array includes a plurality of rows along the first direction and along the A plurality of columns in the second direction where the first direction intersects, the first electrodes in each row correspond to sub-pixels of the same color, and the first electrodes corresponding to the red sub-pixels and the green sub-pixels each include and are spaced apart from each other along the second direction and Two adjacent sub-electrodes that are electrically insulated, the ratio of the size of the sub-electrodes along the first direction to the size along the second direction is greater than 1;
  • the light-emitting layer on the first electrode array at least includes a red light-emitting layer corresponding to the red sub-pixel, a blue light-emitting layer corresponding to the blue sub-pixel, and a green light-emitting layer corresponding to the green sub-pixel;
  • the blue light emitting layer is located between the red light emitting layer and the green light emitting layer;
  • two adjacent light-emitting layers respectively located in different pixels emit light of the same color.
  • FIG. 1 shows a schematic diagram of the preparation of a light-emitting device by an inkjet printing method in the prior art
  • Fig. 2 shows a schematic diagram of a light emitting device according to an embodiment of the present disclosure
  • Fig. 3 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure
  • 4A-4C are schematic diagrams illustrating the relationship between a unit of a printed light-emitting layer and a lower electrode according to an embodiment of the present disclosure
  • 5A and 5B are schematic diagrams illustrating the relationship between units of a printed light-emitting layer and lower electrodes according to another embodiment of the present disclosure
  • 6A-6E show schematic diagrams of a method for fabricating a light-emitting device according to an embodiment of the present disclosure
  • Fig. 7 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • Fig. 8 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • Fig. 9 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • FIG. 10A shows a photomicrograph of a printed quantum dot (QD) layer in a light-emitting device prepared according to an example of the present disclosure
  • FIG. 10B shows a stalk scan result corresponding to the region shown in FIG. 10A .
  • FIGS. 11A-11C show schematic diagrams of light emitting devices according to some embodiments of the present disclosure.
  • FIGS. 12A and 12B show schematic diagrams of light emitting devices according to other embodiments of the present disclosure.
  • FIGS. 13A and 13B show schematic diagrams of light emitting devices according to other embodiments of the present disclosure.
  • Fig. 14 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • Fig. 15 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • 16A-16D are schematic diagrams illustrating a method of manufacturing a light emitting device according to an embodiment of the present disclosure
  • FIG. 17 shows the results of sphenometry measurements of QLEDs according to Comparative Example 3.
  • Fig. 18 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • 19A and 19B show photomicrographs and spherometer measurement results of a QLED light-emitting device according to Example 2 of the present disclosure
  • FIG. 21 shows a photomicrograph of a QLED light-emitting device as Comparative Example 2;
  • FIG. 22 shows a flowchart of a method of manufacturing a display device according to an embodiment of the present disclosure
  • 23A-23F show schematic diagrams of a method of manufacturing a display device according to an embodiment of the present disclosure
  • FIG. 24 shows a photo of a QLED display device obtained according to the manufacturing method described in FIG. 22 of the present disclosure
  • 25A and 25B show schematic diagrams of a first electrode array in the process of manufacturing a display device according to an embodiment of the present disclosure
  • FIG. 26 shows a schematic diagram illustrating a first electrode array in the process of manufacturing a display device according to an embodiment of the present disclosure
  • FIG. 27 shows the results of spirometer measurements of QLEDs according to Example 3 of the present disclosure
  • FIG. 28 shows the results of spirometer measurement of QLEDs according to Example 4 of the present disclosure.
  • first”, “second”, and similar terms may also be used herein for reference purposes only, and thus are not intended to be limiting.
  • the words “first,” “second,” and other such numerical terms referring to structures or elements do not imply a sequence or order unless clearly indicated by the context.
  • 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).
  • a pixel defining layer (bank) is generally fabricated on a substrate (which is also referred to as a TFT substrate) on which active devices such as thin film transistors (TFTs) are formed.
  • FIG. 1 shows a schematic diagram of preparing a light-emitting device by an inkjet printing method in the prior art.
  • a pixel defining layer for defining pixel regions is formed on the substrate 3101 , which includes a plurality of isolation structures 3103 .
  • the ink droplet 3107 containing the material for forming the functional layer is spray-printed on the substrate 3101 through the nozzle 3105, so that the functional layer, such as the light emitting layer, is printed on the pixel area defined by the pixel defining layer.
  • the resolution of inkjet printing is limited by the physical spacing of the nozzles of the nozzles and the size of each ink drop ejected from the nozzles.
  • the theoretical maximum resolution ppi 25400/physical spacing of the nozzles. For example, if the physical pitch of the nozzles is 42.33 microns, the maximum printing resolution is 600ppi.
  • the present disclosure aims at at least one of the above problems, and provides a method for manufacturing a display device with higher resolution by using inkjet printing.
  • FIG. 22 shows a flowchart of a method of manufacturing a display device according to an embodiment of the present disclosure.
  • the method for manufacturing a display device mainly includes the following steps:
  • Step 2210 providing a substrate, on which there is a first electrode array composed of a plurality of first electrodes respectively corresponding to blue sub-pixels, green sub-pixels and red sub-pixels, the first electrode array includes multiple electrodes along the first direction rows and a plurality of columns along the second direction intersecting the first direction, the first electrodes in each row correspond to the sub-pixels of the same color, and the first electrodes corresponding to the red sub-pixels and the green sub-pixels respectively include Two adjacent sub-electrodes spaced from each other and electrically insulated in two directions, the ratio of the size of the sub-electrodes along the first direction to the size along the second direction is greater than 1, and the two adjacent sub-electrodes are respectively located in different pixels;
  • Step 2220 while moving the print head along the first direction, make the print head eject ink containing luminescent material to form a luminescent layer on the first electrode, wherein a single nozzle of the print head ejects ink to the two phases
  • the light-emitting layers of two sub-pixels of the same color are formed at the same time.
  • the light-emitting layer of each pixel at least includes a red light-emitting layer corresponding to the red sub-pixel capable of emitting red light, a blue light-emitting layer corresponding to the blue sub-pixel capable of emitting blue light, and a green light-emitting layer corresponding to the green sub-pixel capable of emitting green light.
  • a green light-emitting layer, and in the light-emitting layer of each pixel, along the second direction, the blue light-emitting layer is located between the red light-emitting layer and the green light-emitting layer; and
  • Step 2230 forming a second electrode on the light emitting layer.
  • a method of manufacturing a display device according to the present disclosure will be described in detail below with reference to FIGS. 23A-23F .
  • a first electrode array composed of a plurality of elongated first electrodes 2302 is formed on a substrate 2301 .
  • the size of the elongated first electrodes 2302 along the row direction (first direction) is greater than the size along the column direction (second direction).
  • the row direction and the column direction are shown to be perpendicular to each other, but it should be understood that the present disclosure is not limited thereto as long as the row direction and the column direction intersect.
  • the substrate 2301 may be a transparent substrate such as a glass substrate.
  • a conductive film for example, a transparent conductive film such as ITO
  • ITO transparent conductive film
  • the conductive film is divided according to the predetermined position of each sub-pixel in the display device, thereby forming an anode array (first electrode array) as shown in FIG. 23B .
  • FIG. 23B only shows a part of the first electrode array as a schematic diagram, and the electrode array of an actual display device may have more rows and columns.
  • the first electrodes in the first row and the fifth row correspond to the green sub-pixels
  • the first electrodes in the second row, the fourth row and the sixth row correspond to the blue sub-pixels
  • the first electrodes in the second row, the fourth row and the sixth row correspond to the blue sub-pixels.
  • the first electrodes of the 3rd row and the 7th row correspond to red sub-pixels.
  • the first electrode corresponding to the red sub-pixel and the green sub-pixel is further divided into two sub-electrodes electrically insulated from each other along the row direction (ie, the first direction).
  • the first electrode 2302 corresponding to the green sub-pixel in the first row and the first column is further divided into two sub-electrodes 23021 and 23022 .
  • the first electrodes in row 1, row 3, row 5 and row 7 are all further divided into two sub-electrodes that are electrically insulated from each other.
  • the division of the electrodes can be realized by, for example, etching the electrodes.
  • the etched line width (the space between the two sub-electrodes obtained by dividing the first electrode) can be controlled within, for example, 1 ⁇ m-10 ⁇ m. However, it should be understood that the present disclosure is not limited thereto. It should be noted that the division of the electrodes is preferably completed before starting the printing procedure.
  • the elongated first electrode for example, the sub-electrodes obtained after being divided along the first direction are still elongated. And for the elongated sub-electrodes, the ratio of the size along the first direction to the size along the second direction is 1.5-30. In some embodiments according to the present disclosure, the ratio of the size of the sub-electrode along the first direction to the size along the second direction may be 1.5-20. Further, in some embodiments according to the present disclosure, the ratio of the size of the sub-electrode along the first direction to the size along the second direction may be 1.5-10.
  • each pixel may include three sub-pixels, namely a red sub-pixel, a blue sub-pixel and a green sub-pixel. Dotted lines in FIG. 23C show electrodes corresponding to three subpixels in one pixel.
  • the isolation structure 2308 may be an isolation structure in conventional technology, for example, the height of the isolation structure may be several microns.
  • the uniformity of the film layer of the light-emitting diode is affected by the isolation structure (capillary effect), and it is difficult to achieve uniformity and flatness.
  • the light emitting diode device may include multilayer films (such as hole injection layer, hole transport layer, light emitting layer, electron transport layer, electron injection layer, etc.), so in the case of preparing multilayer films by printing, it is more difficult Make the film layer even and smooth.
  • the upper electrode ie, the top electrode
  • the upper electrode usually covers the entire surface of the functional layer and the top of the isolation structure, and is usually made thinner (typically, tens of nanometers, such as a silver electrode of 20nm), and the total thickness of the film layer is usually only a few hundred nanometers (nm) (for example, 100nm ⁇ 200nm).
  • the height of the isolation structure is usually several micrometers. Therefore, the height difference between the isolation structure and the total thickness of the film layer is very large, which is easy to cause the upper electrode to break.
  • the performance of the light-emitting device prepared by the printing method in the prior art is much lower than that of the light-emitting device prepared by the planar spin-coating method.
  • isolation structures 2308 may also be smaller than 700 nm.
  • the inventors of the present application found that by setting the height of the isolation structure to 700nm or less, the capillary effect of the functional layer at the isolation structure can be reduced. The accumulation at the edge of the film layer causes unevenness of the film layer, which can improve the uniformity of the film layer.
  • the height of the isolation structure to be 700nm or less, the step difference in thickness of the lamination of the isolation structure and the functional layer can be reduced, so that the lap stability of the upper electrode can be improved and its breakage can be reduced.
  • 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 50 nm-200 nm or 55 nm-200 nm.
  • 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 comparison of the height is Relative to a common reference is generally relative to the surface of the first substrate.
  • an isolation structure is provided.
  • the display device may adopt the structure of the display device according to the embodiments of the present disclosure described below with reference to FIGS. height or above to separate the isolation structure of the light-emitting layer.
  • the display device may have functional layers. As shown in FIG. 23D , a hole injection layer 2303 , a hole transport layer 2304 , a light emitting layer 2305 , an electron transport layer 2306 and an electron injection layer 2307 can be sequentially formed on the first electrode.
  • the printing nozzle When preparing the luminescent layer 2305 , the printing nozzle can be moved along the first direction on the substrate 2301 while spraying ink containing luminescent material, so as to form the luminescent layer 2305 on the first electrode.
  • the light-emitting layer 2302 of each pixel at least includes a red light-emitting layer corresponding to the red sub-pixel capable of emitting red light, a blue light-emitting layer corresponding to the blue sub-pixel capable of emitting blue light, and a blue light-emitting layer corresponding to the green sub-pixel capable of emitting green light.
  • a printing device may have a plurality of heads arranged in a row direction, each head usually filled with a color of ink and having a plurality of nozzles arranged in a column direction.
  • each nozzle of the printing device can be controlled to spray ink droplets containing different luminescent materials, thereby simultaneously forming multiple rows of luminescent layers.
  • each nozzle of the printing device may have 4 nozzles arranged in a row along the column direction, and the pitch of the nozzles is equal to the line pitch of the first electrode array.
  • the printing device can move along the row direction for the first time, and the three nozzles can control the corresponding nozzles to eject the ink containing green luminescent material and the ink containing blue luminescent material respectively. Ink and red luminescent material ink.
  • the nozzles of the printing device stop ejecting ink droplets and move downwards in the column direction (second direction), starting from the 5th row and the 1st column, use the corresponding nozzles in the 3 nozzles to print the 5th row to the 7th row respectively.
  • Luminescent material
  • each nozzle of the printing device may have 1 or 2 nozzles, or may have 3 or more nozzles. If the number of nozzles on each nozzle of the printing device is greater than or equal to the number of rows of the luminescent layer of the corresponding color, it is often only necessary to perform one printing along the row direction to complete the production of the luminescent layer without moving along the column direction.
  • the pitch of the nozzles is greater than the row pitch of the light emitting layers of the corresponding colors.
  • the nozzles of the printing device may first move along the row direction and eject ink to form one or more rows of light-emitting layers of corresponding colors. Then, after the nozzle head of the printing device is shifted by a predetermined distance along the column direction, the nozzle head is moved along the row direction and ejects ink to form another row or multiple rows of light-emitting layers.
  • the printing device includes 3 nozzles, each nozzle has two nozzles, and the distance between the nozzles is equal to the distance between the second row and the sixth row in the first electrode array shown in FIG. 23C .
  • the printing device can align the two nozzles of the nozzle for printing the blue luminescent material on the left side of the first column in the second row and the first column in the sixth row, move the nozzle along the row direction and eject the ink containing the blue luminescent material. ink. In this way, light emitting layers corresponding to the blue sub-pixels of the second row and the sixth row can be formed.
  • the print head is translated twice the line distance along the column direction, and the nozzle is aligned to the left side of the 4th row and 1st column.
  • the head is moved again in the row direction and ink containing a blue luminescent material is ejected, thereby forming a luminescent layer corresponding to the blue sub-pixel of the 4th row.
  • one nozzle when the nozzle moves along the row direction, one nozzle may eject ink containing a green luminescent material on a row of first electrodes corresponding to green pixels. Since each first electrode corresponding to the green sub-pixel contains two sub-electrodes, the shower head only needs to move once along the row direction, and a single nozzle can be used to spray each sub-electrode of a row of first electrodes corresponding to the green sub-pixel (that is, adjacent two sub-electrodes). A green light-emitting layer is formed on the row sub-electrodes).
  • the nozzle can also be moved once along the row direction, and a single nozzle can be used to spray each sub-electrode of the first electrode of a row corresponding to the red sub-pixels (that is, adjacent A red light-emitting layer is formed on two rows of sub-electrodes).
  • a cathode (second electrode) 2309 is formed, thereby obtaining a display device according to an embodiment of the present disclosure.
  • FIG. 23F shows a schematic diagram of pixel arrangement in the display device obtained in the above manner.
  • the width (dimension in the column direction) of each blue sub-pixel B is equal to the width of the overlapping portion.
  • the width of the blue light-emitting layer depends on the width of the light-emitting material that can be formed by a single nozzle of the shower head.
  • the width of each green sub-pixel G and red sub-pixel R (in the column direction size) can be reduced to the width of the overlapping portion between the light-emitting layer that can be formed by a single nozzle of the shower head and the corresponding electrodes 23021, 23022 below.
  • one pixel 2310 in the display device may include the blue sub-pixel B in the 4th row and 1st column, the lower red sub-pixel 2305 in the 3rd row and 1st column, and the 5th row and 1st column.
  • adjacent two light emitting layers respectively located in different pixels emit light of the same color.
  • dashed line in FIG. 23F there are two adjacent pixels 2310 and 2320 in the first column.
  • Green subpixel 2306 in pixel 2310 is adjacent to green subpixel 2307 in pixel 2320 .
  • pixel 2310 and pixel 2320 are square. However, it should be understood that the present disclosure is not limited thereto. Based on the teaching of the present disclosure, the shape of the pixel can be selected by those skilled in the art according to actual needs.
  • FIG. 24 shows a photo of a QLED display device obtained according to the manufacturing method described in FIG. 22 of the present disclosure.
  • the resolution of the display device reaches 150ppi, while the physical resolution of the nozzle for manufacturing the QLED display device is only 100ppi. Therefore, using the manufacturing method of the present disclosure, a display device with a display resolution exceeding the physical resolution of the shower head can be manufactured. In this way, a shower head with low physical resolution can be used to obtain a high-resolution display device.
  • the area of the blue light emitting layer in each sub-pixel is larger than the area of one or both of the red light emitting layer and the green light emitting layer.
  • red luminescent materials and green luminescent materials blue luminescent materials are less stable. Therefore, the blue light emitted by the blue light-emitting material decays faster, which easily leads to the problem of chromatic aberration.
  • the blue luminescent material By arranging the blue luminescent material to have a larger area, the problem of chromatic aberration caused by blue light attenuation can be improved.
  • the area of the blue light emitting layer in the light emitting layer of each pixel, may be twice the area of the green light emitting layer.
  • the area of the blue light emitting layer may be twice that of the red light emitting layer.
  • the area of the red light emitting layer is equal to the area of the green light emitting layer, and the area of the blue light emitting layer is twice the area of the red light emitting layer.
  • each first electrode in the first electrode array formed on the substrate, each first electrode has a square shape. Similar to the embodiment shown in FIG. 23C above, the first electrode corresponding to the green sub-pixel and the red sub-pixel can be further divided into two electrodes that are electrically insulated from each other. As shown in FIG. 25B , the first row and the third row The first electrodes in the 5th row and the 7th row are further divided, so as to obtain respective electrodes corresponding to a single sub-pixel.
  • the shape of each sub-pixel is determined by the shape of its corresponding electrode.
  • the anodes in the red sub-pixel and the green sub-pixel are obtained by dividing the first electrode in a square shape, so the shapes of the red sub-pixel and the green sub-pixel are rectangular, while the anodes in the blue sub-pixel The anode is not divided, so the shape of the blue subpixel is square.
  • FIG. 26 shows a schematic diagram of a first electrode array in the process of manufacturing a display device according to an embodiment of the present disclosure.
  • each first electrode in the first electrode array formed on the substrate, each first electrode has a circular shape. Similar to the embodiment shown in FIG. 23C above, the first electrode corresponding to the green sub-pixel and the red sub-pixel can be further divided into two mutually electrically insulated electrodes. As shown in FIG. 26 , the first row and the third row and the first electrode of the 5th row are further divided to obtain respective electrodes corresponding to a single sub-pixel.
  • the anodes in the red sub-pixel and the green sub-pixel are divided by the circular first electrode, so the shapes of the red sub-pixel and the green sub-pixel are semicircular, while the anodes in the blue sub-pixel The anode is not divided, so the shape of the blue subpixel is circular.
  • the shape of the first electrode according to the embodiments of the present disclosure is not limited to the above-mentioned strip shape, square shape and circle shape, and may also be other suitable shapes, such as ellipse, rhombus, triangle, hexagon or other polygons wait.
  • a display device without an isolation structure will be further described in detail with reference to FIGS. 2-10B .
  • a display device according to the present disclosure may include a light emitting device as well as other devices, such as a power source, etc. (not shown).
  • the structure and characteristics of the light-emitting part (ie, the light-emitting device) in the display device are mainly shown and described, and other devices are similar to the prior art, so the present disclosure will not describe and introduce them in detail.
  • Fig. 2 shows a schematic diagram of a light emitting device according to an embodiment of the present disclosure.
  • the light emitting device 200 includes a first substrate 101 .
  • a plurality of first electrodes 103 are formed on the first substrate 101 .
  • the light emitting device 200 further includes a stack of functional layers (not denoted by reference numerals) located on the plurality of first electrodes.
  • the stack includes at least a light-emitting layer, and the light-emitting layer includes a plurality of units 107 that are independent of each other.
  • the plurality of units 107 are shown separated from each other.
  • the plurality of units 107 are arranged corresponding to the corresponding first electrodes, for example, in some implementations, the units 107 may be arranged in one-to-one correspondence with the first electrodes 103 .
  • no isolation structure extending from the first substrate or the first electrode to the height of the unit 107 or above to separate the plurality of units is provided between the plurality of units 107 .
  • the multiple units 107 are configured such that the orthographic projection of each unit 107 on the first substrate 101 covers the corresponding orthographic projection of the first electrode 103 on the first substrate. In this way, the luminous efficiency can be improved; the luminescence can also be made uniform. On the other hand, the influence of adjacent pixels (or sub-pixels) on the current pixel (or sub-pixels) can also be reduced. More details will be described later in conjunction with FIGS. 4A-4C and 5A and 5B.
  • the light emitting layer may also be denoted by reference numeral 107 when necessary.
  • a lower functional layer 105 below the light-emitting layer (which includes the unit 107) and an upper functional layer 109 above the light-emitting layer are also shown.
  • the lower functional layer 105 or the upper functional layer 109 is optional.
  • the lower functional layer 105 and the upper functional layer 109 are shown as a single layer in FIG. 2, they may be multi-layered.
  • one or more functional layers are shown as monolithic, that is, the functional layer can be used for multiple pixels or sub-pixels, but in other embodiments In , the functional layer can also include multiple units, and a single unit can be used for one or more pixels or sub-pixels.
  • 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.
  • Functional layers may include at least one of a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an electron blocking layer, a buffer layer, and/or any layer that performs other desired functions, and the like.
  • an electrode or functional layer can be shared for two pixels.
  • the plurality of units 107 are shown separated from each other, with at least a portion of the upper functional layer 109 located between units of the plurality of units 107 .
  • the multiple units 107 are arranged on the same layer.
  • the plurality of units 107 are arranged in the same layer, and the thicknesses are substantially the same within the range of process precision.
  • the thicknesses of the plurality of units 107 capable of emitting light in different wavelength bands may also be different.
  • At least a portion of upper functional layer 109 is in contact with a portion of lower functional layer 105 below the light-emitting layer that is not shielded by said light-emitting layer.
  • the units of the emissive layer are formed by drying printed ink droplets containing quantum dot material. In this way, a quantum dot display device can be formed.
  • quantum dots can be configured to be uniformly dispersed in ink droplets.
  • a portion of the lower functional layer 105 (or one or more layers therein) below the light-emitting layer 107 may be treated so that its surface properties differ from other portions, thereby affecting the printing of ink droplets. Influence.
  • part of the surface of the lower functional layer (or one or more layers thereof) can be treated with ultraviolet light, thereby changing its hydrophilicity, hydrophobicity or other properties.
  • the functional layers are usually layers that have requirements for optoelectronic properties or other properties, and their components are complex, such treatment may cause adverse effects on optoelectronic properties, chemical properties, or surface flatness, thereby affecting device performance.
  • the materials of each functional layer are required to have the same surface affinity, so the selection of materials for the functional layers is more stringent, and at the same time, the optoelectronic performance of the light-emitting device needs to be considered.
  • such a treatment is not performed, but the portion of the lower functional layer that overlaps with the units of the light-emitting layer overlaps with the units of the lower functional layer that do not overlap with the units of the light-emitting layer.
  • the surface properties of the overlapping parts are consistent. In this way, the process complexity is reduced, the manufacturing efficiency is improved, the cost is reduced, and the impact on device performance is minimized.
  • Fig. 3 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 300 further includes a second electrode 301 located on the stack of functional layers.
  • the second electrode 301 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 301 can be configured to allow light emitted by the light emitting layer to transmit therefrom.
  • the thickness of the second electrode 301 may be hundreds of nanometers, such as 100nm-200nm.
  • Each of the plurality of units 107 of the light emitting layer, a corresponding portion of the corresponding first electrode 103 and the second electrode 301 may be included in a corresponding pixel.
  • the corresponding first electrode 103 , the corresponding part in the stack of functional layers, and the corresponding part of the second electrode 301 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).
  • the light emitting device 300 may further include a cover layer 303 disposed on the second electrode 301 .
  • 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 covering layer can be made of organic small molecule materials, such as NPB, Alq, CBP, etc., through a thermal evaporation process; the thickness of the covering layer can be, for example, 20nm-400nm.
  • the cover layer can be made of inorganic materials, such as Al 2 O 3 , Six N y , Six N y O z , etc.; the thickness can be, for example, 20nm-400nm.
  • the covering layer can be made of organic-inorganic hybrid materials by wet film-forming processes, such as slit coating, inkjet printing, ultrasonic spraying, screen printing, etc.; the thickness can be, for example, 300nm-3000nm.
  • the organic material may be polymer resin, such as acrylic resin, epoxy resin, etc., or may be selected from polymethyl methacrylate, polycycloolefin, etc.
  • the inorganic material may be selected from metal compound particles such as alumina, titania, zirconia and the like. Preferably, the particle size of the inorganic particles generally does not exceed 1000 nm.
  • 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.
  • FIGS. 4A-4C illustrate 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 lower electrode 103 is shown as circular.
  • the cells 107 of the luminescent layer are also shown as circular.
  • the unit 107 of the light emitting layer covers the lower electrode (ie, the first electrode) 103 . That is to say, the orthographic projection of the unit 107 of the light emitting layer on the first substrate 101 covers the orthographic projection of the corresponding first electrode 103 on the first substrate.
  • a circle is taken as an example for theoretical calculation. However, in practical applications, those skilled in the art can easily perform calculations according to actual needs according to the principles taught in this application.
  • the light-emitting layer is fabricated by inkjet printing, in which case, the cells formed by ink droplet printing preferably cover the lower electrodes.
  • the radius of the circular unit 107 (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 107 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 107 formed after ink drop drying should be greater than or equal to the radius r of the lower electrode 103 and the printing accuracy (for example, print drop point The sum of errors) a, that is, R ⁇ r+a. Therefore, it can be ensured that the units 107 of the light-emitting layer formed by printing can completely cover the lower electrode 103 under the condition of the printing accuracy a.
  • FIG. 4B shows two adjacent units 107 of the light emitting layer and corresponding adjacent two lower electrodes 103 .
  • the radii of the two units 107 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 107 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 after the ink droplet is dried and the size and spacing of the lower electrodes can be based on different display resolutions, different pixel designs (for example, different geometric shapes and sizes), and whether partial overlap is allowed. Design, equipment accuracy, etc. should be considered.
  • 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 4C.
  • 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.
  • the ratio of the diameters of the units formed by the ink droplets containing the quantum dot material before and after drying may be about 1.5:1 to about 1.1:1.
  • 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 the thickness of the film layer.
  • 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. 5A and 5B 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 107 formed by ink droplet printing is in the shape of a strip with a width of L; the corresponding lower electrode is also in the shape of a strip 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 centerline of the cell 107 formed by ink droplet printing is aligned with the centerline of the lower electrode.
  • the unit 107 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. 5B shows the situation of adjacent cells 1071 and 1072 and corresponding adjacent lower electrodes 1031 and 1032 .
  • Each unit 1071 and 1072 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.
  • the widths (lateral dimensions) of the two units 1071 and 1072 are L1 and L2 respectively
  • the printing precisions are a1 and a2 respectively
  • the widths (lateral dimensions) of the two first electrodes 1031 and 1032 are l1 respectively and l2.
  • each unit 1071 and 1072 and the corresponding lower electrodes 1031 and 1032 meet the aforementioned configuration, that is, the half-width L1/2 of the unit 1071 is greater than or equal to the difference between the half-width l1/2 of the corresponding first electrode 1031 and the printing accuracy a1 and (L1/2 ⁇ l1/2+a1), the half-width L1/2 of the unit 1072 is greater than or equal to the sum of the half-width l2/2 of the corresponding first electrode 1032 and the printing accuracy a2 (L2/2 ⁇ l2/2 +a2). .
  • the initial conditions are set: 100ppi resolution, red, green and blue pixels are equal in width and distance, and the accuracy of the printing device is 10 microns.
  • 6A-6E show schematic diagrams of a method for fabricating a light emitting device according to an embodiment of the present disclosure.
  • a first substrate 101 having a plurality of first electrodes 103 thereon is provided.
  • the first substrate 101 may be a TFT substrate (which may also be called a pixel substrate).
  • the first substrate may be cleaned.
  • the substrate is cleaned with a cleaning agent, rinsed with water, and then dried, and then subjected to surface plasma treatment for use.
  • a stack of functional layers including at least a light emitting layer including a plurality of units 107 is formed on the first substrate 101 .
  • the plurality of units 107 are arranged corresponding to the corresponding first electrodes.
  • the isolation structure is also called pixel definition layer (PDL) in the prior art.
  • forming a stack of functional layers on the first substrate 101 may include the following steps: forming the light-emitting layer corresponding to the plurality of first electrodes by an inkjet printing method.
  • the ink droplets contain quantum dot materials; the liquid printing units are dried to form the plurality of units of the luminescent layer.
  • the orthographic projection of each unit of the plurality of units on the first substrate covers the orthographic projection of the corresponding first electrode on the first substrate.
  • the preparation method of the light-emitting device does not include hydrophilic treatment or hydrophobic treatment on any layer of electrodes or functional layers.
  • a lower functional layer 105 is formed, and the lower functional layer covers at least the plurality of first electrodes 103; The plurality of units 107 of the light emitting layer are formed on the lower functional layer.
  • the lower functional layer 105 may include a hole injection layer and a hole transport layer (not shown in the figure).
  • 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. After coating, the substrate is placed on a hot plate, to dry. Afterwards, the hole transport layer can be prepared as follows: the hole transport layer material is made into a printable formula, printed, and printed on the above hole injection layer material; then the substrate is transferred 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 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.
  • 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 lower 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.
  • 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 301 is formed on the stack of functional layers.
  • the second electrode 301 may be configured to be formed entirely, covering the display area of one or more pixels (or sub-pixels).
  • a covering layer 303 capable of transmitting light is formed on the second electrode.
  • Fig. 7 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 700 further includes a spacer 701 .
  • the spacer 701 is disposed on a side of the second electrode 301 away from the first electrode.
  • the spacer 701 can be used to reduce the impact of pressure or stress on the pixels during packaging, so as to protect the pixels or light emitting units.
  • each of the plurality of units 107 of the light emitting layer, and corresponding portions of the corresponding first electrode 103 and the second electrode 301 may be included in a corresponding pixel. It should also be noted that the pixels referred to in this application may include sub-pixels unless otherwise stated.
  • the spacer 701 is disposed on a side of the second electrode 301 away from the first electrode, and is opposite to the second electrode 301 through the covering layer 303 .
  • the spacer 701 is arranged offset from the pixel, so as to avoid blocking the light emitted by the light-emitting unit, and can prevent pressure or stress from being transmitted to the light-emitting unit of the pixel.
  • spacer 701 is shown formed at the cover layer and shown as an ellipse, this is merely exemplary and the present disclosure is not limited thereto. Spacers 701 may also be provided on a counter substrate (as shown at 801 in FIG. 8 ), which may also take any desired shape.
  • the spacer 701 may be prepared by a printing method, for example, the spacer 701 may be formed by printing ink droplets at a desired position multiple times and drying.
  • the spacer 701 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 thickness of the spacer can be 0.5 micron-5 microns; the shape can be positive trapezoidal (photolithographically formed by positive photoresist) or inverted trapezoidal (photolithographically formed by negative photoresist); the material can be One or more of the following: polymethyl methacrylate (PMMA), polystyrene (PS), polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI), polyurethane (PU) and polyvinyl chloride (PVC).
  • PMMA polymethyl methacrylate
  • PS polystyrene
  • PET polyethylene terephthalate
  • PC polycarbonate
  • PI polyimide
  • PU polyurethane
  • PVC polyvinyl chloride
  • the density and arrangement of the spacers are related to the pixel design and arrangement, and may be lower than the pixel resolution PPI.
  • Fig. 8 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 800 further includes an opposite second substrate 801 .
  • the second substrate 801 and the first substrate 101 may be opposed and packaged.
  • a light emitting unit (stack of the functional layers) is disposed between the first substrate and the second substrate.
  • a filling material 803 may be filled between the second substrate 801 and the first substrate 101 .
  • 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 first substrate may be a pixel substrate for forming pixels, and sometimes it may also be called a TFT substrate.
  • the first substrate may be a substrate without an isolation structure according to any of the foregoing embodiments or implementation manners.
  • the first substrate may be cleaned, for example, solvent cleaning is performed on the first substrate with a cleaning agent, washed with water, and then spin-dried. Next, surface plasma treatment may be performed on the first substrate for use.
  • the hole injection material can be formulated into a solution suitable for coating, and the coating can be performed by selecting appropriate coating parameters. After coating, the substrate was placed on a hot plate to allow the coated solution to dry. Thus, a hole injection layer was formed.
  • a hole transport layer was formed.
  • the material of the hole transport layer can be made into a printable ink formulation, the first substrate on which the hole injection layer is formed is clamped in place, and printed by a printing device (for example, a nanomaterial printing device DMP2831) , so that the material is printed on the hole injection layer.
  • the first substrate may then be dried through a vacuum hot plate.
  • a hole transport layer was formed.
  • a quantum dot (QD) layer is formed.
  • the QD stock solution can be redispersed into the printing solvent formula after centrifugal precipitation to make printable ink and load it into the printing device.
  • the ink containing QD materials is accurately printed on the mutually independent electrode areas of the pixel substrate, and the electrode areas are completely covered.
  • the substrate can be transferred to a vacuum hot plate for vacuum drying. In this way, a quantum dot layer is formed.
  • FIG. 10A shows a photomicrograph of the QD layer printed on the first substrate (here, the pixel substrate) in the light-emitting device prepared according to this example
  • FIG. 10B corresponds to the strophe scan result of the area shown in FIG. 10A
  • the formed QD film layer is substantially uniform from the edge to the middle film layer.
  • 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 subpixel 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 subpixel 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. 11A shows a schematic diagram of a light emitting device according to one embodiment of the present disclosure.
  • a light emitting device 1200A includes a first substrate 1101.
  • the first substrate 1101 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 1103 and a plurality of isolation structures 1105 are formed on the first substrate 1101 .
  • the isolation structure 1105 may serve as a pixel definition layer (PDL) that defines pixels.
  • the isolation structure 1105 is located on the first substrate 1101 and extends upward from the first substrate.
  • the isolation structure 1105 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 1103 may also be referred to as a bottom electrode.
  • the first electrodes 1103 may be disposed between corresponding isolation structures.
  • only one first electrode 1103 is shown, which is arranged between two corresponding isolation structures 1105 .
  • a portion of the isolation structure 1105 may overlap the first electrode 1103 .
  • at least a portion of the first electrode 1103 is disposed between corresponding isolation structures.
  • FIG. 11A only shows a cross-sectional view of a part of the light-emitting device, so components such as the substrate 1101 and the isolation structure 1105 may not be all shown.
  • components such as the substrate 1101 and the isolation structure 1105 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 1105 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. 11B shows a partially enlarged schematic view of some components of the light emitting device according to this embodiment. Unlike FIG. 11A , FIG. 11B shows a complete isolation structure 1105 . As shown in FIGS. 11A and 11B , according to an embodiment of the present disclosure, an isolation structure 1105 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 ).
  • 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.
  • FIGS. 2A and 2B are cross-sections across the isolation structures and light-emitting regions of pixels (or sub-pixels).
  • 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 11A).
  • Some functional layers for example, hole injection layers
  • Some functional 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 may 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 1200A further includes a functional layer 1201 .
  • the functional layer 1201 may be, for example, a hole injection layer (HIL), but the present disclosure is not limited thereto.
  • the functional layer 1201 is formed on the first electrode 1103 and the isolation structure 1105 .
  • the functional layer 1201 can generally 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 1201 is cut off by the isolation structure 1105 and occurs layer breaks.
  • the first portion 1201_1 of the functional layer 1201 on the first electrode 1103 is broken from the second portion 1201_2 on the top surface of the isolation structure. In this way, crosstalk between pixels caused by the lateral conduction of the functional layer 1201 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 1105 is substantially flat.
  • the height of the top surface of the isolation structure 1105 is greater than the height of the functional layer 1201 .
  • the top surface of the isolation structure 1105 may be non-planar.
  • FIG. 11C shows a light emitting device according to one embodiment of the present disclosure.
  • the light emitting device 1200C shown in FIG. 11C may further include an additional functional layer 1203 on the functional layer 1201 .
  • the functional layer 1203 may be, for example, a hole transport layer.
  • the light emitting device 1200C may further include: a light emitting layer 1205 on the functional layer 1203 , and a functional layer 1207 on the light emitting layer 1205 .
  • light emitting layer 1205 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 1207 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 1203 is shown to be substantially flat, that is to say, it basically fills the space between the first part 1201_1 and the second part 1201_2 of the functional layer 1201. height difference.
  • the configuration of the functional layer 1203 can be realized by setting the height of the isolation structure 1105, the formulations of the functional layers 1201 and 1203, 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. 11A and 11C , it may also be shown as a single layer with the upper functional layer 1109 , but it may be multilayered.
  • the light emitting device 1300A shown in FIG. 12A has substantially the same components as the light emitting device 1200C shown in FIG. 11C , 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 1300A shown in FIG. 12A and the light emitting device 1200C shown in FIG. 11C is that the upper surface of the functional layer 1203 is not flat, but is formed with depressions.
  • the light emitting layer 1205 formed after the functional layer 1203 fills the depression and has a substantially flat upper surface.
  • the light emitting device 1300B shown in FIG. 12B has substantially the same components as the light emitting device 1300A shown in FIG. 12A , and the same components are denoted by the same reference numerals, and repeated description thereof will be omitted.
  • the light emitting layer 1205 formed after the functional layer 1203 also fills the depression on the upper surface of the functional layer 1203 .
  • the difference between the light emitting device 1300B shown in FIG. 13B and the light emitting device 1300A shown in FIG. 12A is that the light emitting layer 1205 does not completely cover the entire upper surface of the functional layer 1203 shown in the figure.
  • the printed ink droplets used to form the light emitting layer 1205 may only form on a part of the surface of the functional layer 1203 after drying.
  • the luminescent layer 1205 is disposed corresponding to the first electrode 1103 ; in addition, preferably, the orthographic projection of the luminescent layer 1205 on the substrate 1101 covers the corresponding orthographic projection of the first electrode 1103 on the substrate 1101 . In this way, the coverage of the first electrode 1103 by the light-emitting layer 1205 can be ensured, thereby improving the light emission of the device.
  • the upper functional layer 1207 is in direct contact with the portion of the lower functional layer (eg, 1203 ) that is not covered by the light emitting layer 1205 .
  • 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 1400A includes a first substrate 1101 .
  • a plurality of first electrodes 1103 and a plurality of isolation structures 1105 are formed on the first substrate 1101 .
  • the isolation structure 1105 may serve as a pixel definition layer (PDL) that defines pixels.
  • the isolation structure 1105 is located on the first substrate 1101 and extends upward from the first substrate. At least a portion of the electrodes 1103 may be disposed between corresponding isolation structures.
  • the isolation structure 1105 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 1400A further includes a functional layer 1201 .
  • the functional layer 1201 may be, for example, a hole injection layer (HIL).
  • HIL hole injection layer
  • the functional layer 1201 is formed on the first electrode 1103 and the isolation structure 1105 .
  • the first portion 1201_1 of the functional layer 1201 on the first electrode 1103 is broken from the second portion 1201_2 on the top surface of the isolation structure.
  • the light emitting device 1400A may further include an additional functional layer 1203 on the functional layer 1201 .
  • the functional layer 1203 is also broken.
  • the functional layer 1203 includes a first portion 1203_1 located above the first electrode 1103 and a second portion 1203_2 located above the top surface of the isolation structure, both of which are separated from each other rather than continuous.
  • the functional layer 1203 may be, for example, a hole transport layer.
  • Fig. 13B shows a schematic diagram of a light emitting device according to another embodiment.
  • the light emitting device 1400B shown in FIG. 13B may further include: a light emitting layer 1205 on the functional layer 1203 , and a functional layer 1207 on the light emitting layer 1205 .
  • light emitting layer 1205 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 1205 is printed in the region defined by the isolation structure 1105 by a printing method.
  • the light emitting layer 1205 may also exceed the boundary of the space formed by the stack.
  • the upper functional layer 1207 substantially fills the depression in the space formed by the stack (if the light emitting layer 1205 fails to completely fill the space).
  • the configuration of the functional layer 1207 can be realized by setting the height of the isolation structure 1105, the formulations of the functional layers 1201 and 1203, the light-emitting layer 1205, the properties of the configured solution, 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. 13A and 13B the same reference numerals are used for the same or corresponding components as those shown in FIGS. 11A-12B. Therefore, the above descriptions for each component can be applied here equally or adaptively, and detailed description thereof will not be repeated.
  • Fig. 14 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 1500 shown in FIG. 14 further includes a second electrode (upper electrode) 1501 on the stack of functional layers (not marked with reference numerals).
  • the second electrode 1501 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 1501 can be configured to allow the light emitted by the light-emitting layer to transmit therefrom.
  • the second electrode 1501 can be formed of a light-transmitting material such as ITO or a thin MgAg alloy.
  • the thickness of the second electrode 1501 may be hundreds of nanometers, such as 100nm-200nm.
  • Corresponding portions of the light emitting layer 1205, the corresponding first electrode 1103, and the second electrode 1501 may be included in the corresponding pixel.
  • the corresponding first electrode 1103 , the corresponding part in the stack of functional layers, and the corresponding part of the second electrode 1501 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 refer to a pixel or a sub-pixel unless otherwise specified or the context gives a contrary meaning.
  • the light emitting device 1500 may further include a cover layer 1503 disposed on the second electrode 1501 .
  • 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 1501 is further shown here based on the embodiment shown in FIG. 11A and FIG. 11C , those skilled in the art will know that the upper electrode 1501 can be similarly or similarly formed in other embodiments based on the teachings of the present disclosure. No specific description will be given here.
  • Fig. 15 shows a schematic diagram of a light emitting device according to another embodiment of the present disclosure.
  • the light emitting device 1600 includes a first substrate 1101 .
  • a plurality of first electrodes 1103 and a plurality of isolation structures 1105 are formed on the first substrate 1101 .
  • the isolation structure 1105 may serve as a pixel definition layer (PDL) that defines pixels.
  • PDL pixel definition layer
  • the isolation structure 1105 is located on the first substrate 1101 and extends upward from the first substrate. At least a portion of the electrodes 1103 may be disposed between corresponding isolation structures.
  • the isolation structure 1105 of the light emitting device 1600 is configured differently from the isolation structures shown in FIGS. 11A-14 .
  • the isolation structure 1105 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 1105 This is achieved by forming a concave recess 1611 on the top.
  • the recess 1611 can be realized by, for example, wet etching or dry etching.
  • the light emitting device 1600 also includes a functional layer 1601 .
  • the functional layer 1601 may be, for example, a hole injection layer (HIL).
  • HIL hole injection layer
  • the functional layer 1601 is formed on the first electrode 1103 and the isolation structure 1105 .
  • the first portion 1601_1 of the functional layer 1601 on the first electrode 1103 is broken from the second portion 1601_2 on the top surface of the isolation structure.
  • openings are formed between isolation structures 1105 as shown.
  • the upper surface of the open space is larger than the bottom surface. In this way, the breakage of the functional layer 1601 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.
  • the isolation structure for example, an inverted trapezoid or a half inverted trapezoid
  • 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.
  • 16A-16D show schematic diagrams of a method of manufacturing a light emitting device according to an embodiment of the present disclosure.
  • a first substrate 1101 is provided on which a first electrode 1103 is formed.
  • An isolation structure material layer 1701 is formed on the first substrate 1101 .
  • the isolation structure material layer 1701 covers the first substrate 1101 and the first electrode 1103 .
  • the isolation structure material layer 1701 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 1703 is formed on the isolation structure material layer.
  • the mask 1703 may be formed of photoresist, or may also be formed of a hard mask material.
  • the direction of the first substrate 1101 and the ion or plasma flow 1707 to be used to etch the isolation structure material layer 1701 are angled.
  • the first substrate 1101 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 1705.
  • Angle ⁇ that is, an inclination of 90°- ⁇ with respect to the horizontal direction.
  • the first substrate 1101 may be tilted at an angle smaller than or equal to 30 degrees with respect to the horizontal direction.
  • the direction of the jet 1707 of ions or plasma used for etching is substantially aligned with the direction of the rotation axis.
  • the ion flow is used to etch the isolation structure material layer.
  • 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. 16D . 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.
  • an isotropic etchant may be used to etch the isolation structure material layer to form multiple isolation structures, as shown in FIG. 15 .
  • 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.
  • a light emitting device 1900 may include a first substrate 1901 and an opposite second substrate 1905 .
  • a plurality of pixels 1903 may be formed on the first substrate 1901 .
  • the pixel 1903 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 1907 are formed on the second substrate 1905 .
  • the first substrate 1901 and the second substrate 1905 are encapsulated by an encapsulation compound 1911 , and a filler 1909 may be filled between the first substrate 1901 and the second substrate 1905 .
  • spacer 1907 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 1907 may be prepared by a printing method, for example, the spacer 1907 may be formed by printing ink droplets at desired positions multiple times and drying.
  • the spacers 1907 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.
  • a substrate is provided, on which there is a first electrode array composed of a plurality of elongated first electrodes.
  • the size of the elongated first electrodes along the row direction (first direction) is greater than the size along the column direction (second direction).
  • the row direction and the column direction are shown to be perpendicular to each other, but it should be understood that the present disclosure is not limited thereto as long as the row direction and the column direction intersect.
  • a glass substrate on which an ITO transparent electrode (as the first electrode) is formed is employed.
  • the first electrode corresponding to the red sub-pixel and the green sub-pixel is further divided into two sub-electrodes electrically insulated from each other along the row direction.
  • the etched line width (the space between the two sub-electrodes obtained by dividing the first electrode) can be controlled within, for example, 1 ⁇ m-10 ⁇ m. However, it should be understood that the present disclosure is not limited thereto.
  • an isolation structure with a height of about 2 microns is formed on the substrate.
  • 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 fabricated.
  • an aqueous solution of PEDOT:PSS which is a polymer of EDOT (3,4-ethylenedioxythiophene monomer), and PSS, which is polystyrene sulfonate, is coated on a clean substrate in an air environment. After the coating was completed, annealing was performed in air, and then transferred to a glove box under nitrogen atmosphere for annealing. Thus, 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 quantum dot is CdZnSeS/ZnS, the concentration is 80mg/mL, and its corresponding emission wavelength is 470nm-485nm). Then transfer to a vacuum hot plate and anneal in a vacuum environment.
  • the thickness of the QD light-emitting layer may range from tens to hundreds of nanometers, such as 10nm-100nm, preferably 15nm-60nm.
  • each first electrode corresponding to the green sub-pixel contains two sub-electrodes
  • the shower head only needs to move once along the row direction, and a single nozzle can be used to spray each sub-electrode of a row of first electrodes corresponding to the green sub-pixel (that is, adjacent two sub-electrodes).
  • a green light-emitting layer is formed on the row sub-electrodes).
  • the nozzle can also be moved once along the row direction, and a single nozzle can be used to spray each sub-electrode of the first electrode of a row corresponding to the red sub-pixels (that is, adjacent A red light-emitting layer is formed on two rows of sub-electrodes).
  • 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.
  • FIG. 24 shows a photomicrograph of lighting up of the QLED device according to Example 1 of the present disclosure.
  • Example 1 a nozzle with a physical resolution of 100ppi was used for printing, and the resulting QLED device had a resolution of 150ppi, a pixel size of 169.33 ⁇ 169.33 microns, and each pixel included an undivided blue sub-pixel in the middle and The divided red and green sub-pixels adjacent to the blue pixel, in which the blue sub-pixel is 139.33 microns long, 50 microns wide, and the aspect ratio is 2.79; the red and green sub-pixels are 139.33 microns long, 9.67 microns wide, and the aspect ratio is 14.41. It can be seen from Figure 24 that each sub-pixel emits light evenly and has no color crossover. It is better to use a low-resolution nozzle to print a high-resolution display substrate, which reduces the difficulty of printing and improves the yield rate.
  • This Example 2 prepared a light emitting device with a short isolation structure according to some embodiments of the present disclosure.
  • the substrate has a short isolation structure having a height greater than 50 nm (here, about 55 nm) as a pixel isolation structure.
  • 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.
  • example 2 is to illustrate the technical effect of the short isolation structure according to the present disclosure. Therefore, another difference between example 2 and example 1 is that the electrodes and light-emitting layers of each sub-pixel adopt the traditional structure of the prior art and the traditional Made by inkjet printing. That is, in Example 2, each first electrode is not further divided into two sub-electrodes.
  • Example 1 a substrate without an isolation structure (non-pixel substrate, emitting light from the entire surface) was used, and all functional layer materials were consistent with those in Example 2 above and had substantially 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 on it is provided as a pixel substrate to print red, green and blue devices, and the preparation process of each corresponding film layer is the same as that of the above-mentioned example 2, the difference The only difference lies in the geometric size and shape of the isolation structure.
  • Example 3 substantially the same device was fabricated using substantially the same conditions as in Example 2 above, except that the height of the isolation structure was 1000 nm.
  • 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 2 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. 19A and 19B show micrographs and profilometer measurement results of the QLED light emitting device according to the above-mentioned Example 2 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. 19A there is no edge push-up phenomenon.
  • From the step meter film thickness photo in Figure 19B it can be seen that the film layer in the pixel is uniform, which also verifies the phenomenon of no accumulation.
  • FIGS. 20A-20D 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. 20A-20D , 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. 21 shows a microscope photo of the RGB three-color light emission of the QLED light emitting device with a high isolation structure in Comparative Example 2 above. 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. 27 shows the results of spirometer measurement of QLEDs according to Example 3 of the present disclosure.
  • the difference from example 2 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. 28 shows the results of spirometer measurement of QLEDs according to Example 4 of the present disclosure.
  • the difference from example 2 is only that the height of the isolation structure is 600 nm.
  • the measurement result of the step meter shows that the edge of the functional layer stack at the isolation structure is lifted up, and there is an accumulation of about 18nm.
  • FIG. 17 shows the results of sphenometer measurement of the QLED according to Comparative Example 3.
  • the only difference from Example 2 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.
  • the word "exemplary” means “serving as an example, instance, or illustration” rather than as a “model” to be exactly reproduced. Any implementation described illustratively herein is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, the disclosure is not to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or detailed description.
  • the term “provide” is used broadly to cover all ways of obtaining an object, so “provide something” includes, but is not limited to, “purchasing”, “preparing/manufacturing”, “arranging/setting”, “installing/ Assembly”, and/or “Order” objects, etc.

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Abstract

本公开涉及显示装置及制造显示装置的方法。一种制造显示装置的方法，包括：提供基板，在基板上具有由分别对应于蓝色子像素、绿色子像素和红色子像素的多个第一电极构成的第一电极阵列，第一电极阵列包括沿第一方向的多个行以及沿与第一方向相交的第二方向的多个列，每行中的第一电极对应于相同颜色的子像素，对应于红色子像素和绿色子像素的第一电极各自包含沿第二方向彼此间隔且电绝缘的两个相邻的子电极，子电极沿第一方向的尺寸与沿第二方向的尺寸的比值为大于1，相邻的两个子电极分别位于不同的像素中；沿第一方向移动打印喷头的同时，使打印喷头喷射包含发光材料的墨水，以在所述第一电极上形成发光层；以及在发光层上形成第二电极。

Description

显示装置及制造显示装置的方法 技术领域
本公开涉及显示装置以及制造显示装置的方法。
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，通过多个发彩色光的像素来实现彩色图像的显示。每个像素通常可以包括至少三个子像素，即发蓝色光的蓝色子像素、发绿色光的绿色子像素以及发红色光的红色子像素。对于有机发光二极管(OLED)、量子点发光二极管(QLED)等，可以通过喷墨打印的方式形成各个子像素。
人们为了在有限面积的显示面板上实现更高的分辨率，要求子像素尽可能地小。但是，喷墨打印的方式中，由于喷墨装置的喷孔的尺寸的限制，无法打印更小的子像素。
发明内容
根据本公开的一个方面，提供了一种制造显示装置的方法，包括：
提供基板，在基板上具有由分别对应于蓝色子像素、绿色子像素和红色子像素的多个第一电极构成的第一电极阵列，第一电极阵列包括沿第一方向的多个行以及沿与第一方向相交的第二方向的多个列，每行中的第一电极对应于相同颜色的子像素，对应于红色子像素和绿色子像素的第一电极各自包含沿第二方向彼此间隔且电绝缘的两个相邻的子电极，子电极沿第一方向的尺寸与沿第二方向的尺寸的比值为大于1，相邻的两个子电极分别位于不同的像素中；沿第一方向移动打印喷头的同时，使打印喷头喷射包含发光材料的墨水，以在所述第一电极上形成发光层，其中，打印喷头的单个喷嘴喷射墨水至所述两个相邻的子电极上，同时 形成两个相同颜色的子像素的发光层；以及
在发光层上形成第二电极，
其中，每个像素的发光层至少包含对应于红色子像素的红色发光层、对应于蓝色子像素的蓝色发光层和对应于绿色子像素的绿色发光层，并且在每个像素的发光层中，沿第二方向，蓝色发光层位于红色发光层与绿色发光层之间。
根据本公开的另一个方面，提供了一种显示装置，包括：
基板；
位于基板上的、由分别对应于蓝色子像素、绿色子像素和红色子像素的多个第一电极构成的第一电极阵列，第一电极阵列包括沿第一方向的多个行以及沿与第一方向相交的第二方向的多个列，每行中的第一电极对应于相同颜色的子像素，对应于红色子像素和绿色子像素的第一电极各自包含沿第二方向彼此间隔且电绝缘的两个相邻的子电极，子电极沿第一方向的尺寸与沿第二方向的尺寸的比值为大于1；
位于第一电极阵列上的发光层，至少包含对应红色子像素的红色发光层、对应蓝色子像素的蓝色发光层和对应绿色子像素的绿色发光层；
位于发光层上的第二电极；
在每个像素的发光层中，沿第二方向，蓝色发光层位于红色发光层与绿色发光层之间；
对于沿第二方向相邻的两个像素，分别位于不同像素中的相邻的两个发光层发出相同颜色的光。
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更为清楚。
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喷墨打印法制备发光装置的示意图；
图2示出了根据本公开一个实施例的发光装置的示意图；
图3示出了根据本公开另一实施例的发光装置的示意图；
图4A-4C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5A和5B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；
图6A-6E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7示出了根据本公开另一实施例的发光装置的示意图；
图8示出了根据本公开另一实施例的发光装置的示意图；
图9示出了根据本公开另一实施例的发光装置的示意图；以及
图10A示出了根据本公开一个实例制备的发光装置中打印的量子点(QD)层的显微镜照片，而图10B示出了与图10A所示的区域相应的台阶仪扫描结果。
图11A-11C示出了根据本公开一些实施例的发光装置的示意图；
图12A和12B示出了根据本公开另一些实施例的发光装置的示意图；
图13A和13B示出了根据本公开另一些实施例的发光装置的示意图；
图14示出了根据本公开另一实施例的发光装置的示意图；
图15示出了根据本公开另一实施例的发光装置的示意图；
图16A-16D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17示出了根据对比例3的QLED的台阶仪测量结果；
图18示出了根据本公开另一实施例的发光装置的示意图；
图19A和19B示出了根据本公开实例2的QLED发光装置的显微照片和台阶仪测量结果；
图20A-20D分别示出了根据本公开实例2的单色和彩色QLED 发光装置的显微照片；
图21示出了作为对比例2的QLED发光装置的显微照片；
图22示出了根据本公开的实施例的制造显示装置的方法的流程图；
图23A-23F示出了根据本公开的实施例的制造显示装置的方法的示意图；
图24示出了根据本公开的图22所述的制造方法得到的QLED显示装置的照片；
图25A和25B示出了根据本公开的实施例的制造显示装置过程中的第一电极阵列的示意图；
图26示出了示出了根据本公开的实施例的制造显示装置过程中的第一电极阵列的示意图；
图27示出了根据本公开实例3的QLED的台阶仪测量结果；
图28示出了根据本公开实例4的QLED的台阶仪测量结果。
注意，在以下说明的实施方式中，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。在一些情况中，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，本公开并不限于附图等所公开的位置、尺寸及范围等。
具体实施方式
下面将参照附图来详细描述本公开的各种示例性实施例。应注意到：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。
以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决 不作为对本公开及其应用或使用的任何限制。也就是说，本文中的结构及方法是以示例性的方式示出，来说明本公开中的结构和方法的不同实施例。然而，本领域技术人员将会理解，它们仅仅说明可以用来实施的本公开的示例性方式，而不是穷尽的方式。此外，附图不必按比例绘制，一些特征可能被放大以示出具体组件的细节。
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。
另外，仅仅为了参考的目的，还可以在本文中使用“第一”、“第二”等类似术语，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。
应当理解，在本公开中描述各层结构时，“在……上”和“在……下”的描述仅用于表示层与层之间的相对位置，并且可以包含直接接触以及非直接接触(即存在中间层)的情况。
在这里示出和讨论的所有示例中，任何具体值应被解释为仅仅是示例性的，而不是作为限制。因此，示例性实施例的其它示例可以具有不同的值。
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(bank)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)。
图1示出了现有技术中的喷墨打印法制备发光装置的示意图。如图1所示，基板3101上形成有用于限定像素区域的像素界定层，其包括多个隔离结构3103。通过喷嘴3105将含有用于形成功能层的材料的墨滴3107喷印在基板3101上，从而在像素界定层所限定的像素区域打印功能层，比如发光层等。
然而，喷墨打印的分辨率受限于喷头的喷嘴的物理间距以及喷嘴喷出的每一滴墨滴的大小，理论上最大的分辨率ppi＝25400/喷头物理间距。例如，喷头的物理间距是42.33微米，则打印的最大分辨率是600ppi。但考虑到每个子像素坑的体积(子像素坑体积＝子像素长×子像素宽×隔离结构的高度)，需要大于每一滴墨滴的体积，导致实际上打印工艺的上限为300ppi。
本公开针对上述问题中的至少一个，提供一种使用喷墨打印的方式制造具有更高分辨率的显示装置的方法。
图22示出了根据本公开的实施例的制造显示装置的方法的流程图。
如图22所示，根据本公开的实施例的制造显示装置的方法主要包括以下步骤：
步骤2210，提供基板，在基板上具有由分别对应于蓝色子像素、绿色子像素和红色子像素的多个第一电极构成的第一电极阵列，第一电极阵列包括沿第一方向的多个行以及沿与第一方向相交的第二方向的多个列，每行中的第一电极对应于相同颜色的子像素，对应于红色子像素和绿色子像素的第一电极各自包含沿第二方向彼此间隔且电绝缘的两个相邻的子电极，子电极沿第一方向的尺寸与沿第二方向的尺寸的比值为大于1，相邻的两个子电极分别位于不同的像素中；
步骤2220，沿第一方向移动打印喷头的同时，使打印喷头喷射包含发光材料的墨水，以在所述第一电极上形成发光层，其中，打印喷头的单个喷嘴喷射墨水至所述两个相邻的子电极上，同时形成两个相同颜色的子像素的发光层。每个像素的发光层至少包含能够发出红光的对应于红色子像素的红色发光层、能够发出蓝光的对应于蓝色子像素的蓝色发光层和能够发出绿光的对应于绿色子像素的绿色发光层，并且在每个像素的发光层中，沿第二方向，蓝色发光层位于红色发光层与绿色发光层之间；以及
步骤2230，在发光层上形成第二电极。
下面将结合附图23A-图23F详细描述根据本公开的制造显示装置 的方法。
如图23A和图23B所示，首先，在基板2301上形成由多个长条形的第一电极2302构成的第一电极阵列。长条形的第一电极2302沿行方向(第一方向)的尺寸大于沿列方向(第二方向)的尺寸。在该示例性实施例中，行方向和列方向被示出为彼此垂直，但是应当理解，本公开不限于此，只要行方向和列方向相交即可。
基板2301可以为例如玻璃基板等透明基板。在基板2301上沉积导电膜(例如ITO等透明导电膜)。然后，按照显示装置中预定的各个子像素的位置，对导电膜进行分割，从而形成如图23B所示的阳极阵列(第一电极阵列)。应当理解，图23B作为示意图仅示出了第一电极阵列的一部分，实际显示装置的电极阵列可以具有更多的行数和列数。
在图23B的第一电极阵列中，第1行和第5行的第一电极对应于绿色子像素，第2行、第4行和第6行的第一电极对应于蓝色子像素，第3行和第7行的第一电极对应于红色子像素。
接下来，沿行方向(即第一方向)将对应于红色子像素和绿色子像素的第一电极进一步分割为彼此电绝缘的两个子电极。如图23C所示，第1行第1列的，对应于绿色子像素的第一电极2302被进一步分割为两个子电极23021和23022。类似地，第1行、第3行、第5行和第7行的第一电极都被进一步分割成两个彼此电绝缘的子电极。电极的分割可以通过例如对电极进行刻蚀的方式实现。刻蚀的线宽(分割第一电极得到的两个子电极之间的间隔)可以控制在例如1微米-10微米。但应理解，本公开不限于此。需要说明的是，电极的分割优选在开始打印程序前完成。
对于例如长条形的第一电极，沿第一方向被分割后得到的子电极仍然为长条形。并且对于长条形的子电极，其沿第一方向的尺寸与沿第二方向的尺寸的比值为1.5-30。在根据本公开的一些实施例中，子电极沿第一方向的尺寸与沿第二方向的尺寸的比值可以为1.5-20。进一步地，在根据本公开的一些实施例中，子电极沿第一方向的尺寸与 沿第二方向的尺寸的比值可以为1.5-10。
在一些实施例的显示装置中，每个像素可以包含三个子像素，即红色子像素、蓝色子像素和绿色子像素。在图23C中的虚线示出了对应于一个像素中的三种子像素的电极。
基板2301上可以具有隔离结构2308。在本公开的实施例中，隔离结构2308可以为传统技术中的隔离结构，例如隔离结构的高度可以为几个微米。
然而，如图1所示，当诸如发光层等的功能层是通过喷墨打印(inkjet print)的方法制备时，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，发光二极管装置可以包括多层薄膜(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。
另一方面，上部电极(即顶电极)在隔离结构处搭接稳定性差。上部电极通常整面覆盖功能层和隔离结构顶部，通常制作较薄(典型地，为几十纳米，例如20nm的银电极)，而且膜层总厚度通常只有几百纳米(nm)(例如，100nm～200nm)。而隔离结构的高度通常达数微米。因此隔离结构和膜层总厚度的高度差很大，易于造成上部电极断裂。
因此，现有技术中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。
在根据本公开的一些实施例中，隔离结构2308也可以小于700nm。如后面将参照11A-图21以及图27-图28所述，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稳定性，并减少其断裂。
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50nm-200nm或55nm-200nm。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)。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。
此外，在上面根据本公开的实施例的显示装置中，设置有隔离结构。但是，应当理解，本公开不限于此。例如，根据本公开的一些实施例，显示装置可以采用下面参照图2-图11B描述的根据本公开的实施例中的显示装置的结构，即未设置有从基板或第一电极延伸至发光层的高度或以上从而分隔所述发光层的隔离结构。
显示装置可以具有功能层。如图23D所示，可以在第一电极上依次形成空穴注入层2303、空穴传输层2304、发光层2305、电子传输层2306以及电子注入层2307。
在制备发光层2305时，可以使打印喷头在基板2301上沿第一方向移动，同时喷射包含发光材料的墨水，以在第一电极上形成发光层2305。
每个像素的发光层2302至少包含能够发出红光的对应于红色子像素的红色发光层、能够发出蓝光的对应于蓝色子像素的蓝色发光层和能够发出绿光的对应于绿色子像素的绿色发光层，并且在每个像素的发光层中，沿与行方向(第一方向)垂直的列方向(第二方向)，蓝色发光层材料位于红色发光层与绿色发光层之间。
打印设备可以具有沿行方向排列的多个喷头，每个喷头通常装有一种颜色的墨水并且具有沿列方向排列的多个喷嘴。在制作发光层2303时，可以控制打印设备的各个喷头，喷射包含不同的发光材料的 墨滴，从而同时形成多行发光层。例如，打印设备的每个喷头可以具有沿列方向排成一列的4个喷嘴，并且喷嘴的间距等于第一电极阵列的行距。在图23C所示的第一电极阵列结构的示例中，打印设备第一次可以沿着行方向移动，并且3个喷头可以控制对应的喷嘴分别喷射包含绿色发光材料的墨水、蓝色发光材料的墨水和红色发光材料的墨水。
然后，打印设备的喷头停止喷射墨滴并沿列方向(第二方向)向下移动，从第5行第1列开始，使用3个喷头中的对应喷嘴分别打印第5行至第7行的发光材料。
应当理解，本公开对打印设备的喷嘴数量没有限制。打印设备的每个喷头可以具有1个或2个喷嘴，也可以具有3个或更多个喷嘴。如果打印设备的每个喷头上的喷嘴数量大于或等于对应的颜色的发光层的行数，往往只需要沿行方向执行一次打印，就可以完成发光层的制作，而不必再沿列方向移动。
在根据本公开的另一个示意性实施例中，喷嘴的间距大于对应颜色的发光层的行距。在这种情况下，打印设备的喷头可以先沿行方向移动并喷射墨水，形成一行或多行对应颜色的发光层。然后，打印设备的喷头沿列方向偏移预定距离后，使喷头沿行方向移动并喷射墨水，形成另外的一行或多行发光层。
例如，打印设备包含3个喷头，每个喷头具有两个喷嘴，喷嘴的间距等于图23C所示的第一电极阵列中第2行与第6行之间的间距。打印设备可以使用于打印蓝色发光材料的喷头的两个喷嘴分别对准第2行第1列和第6行第1列的左侧，沿行方向移动该喷头并喷射包含蓝色发光材料的墨水。这样，可以形成对应于第2行和第6行的蓝色子像素的发光层。然后，喷头沿列方向平移两倍的行距，并且使喷嘴对准第4行第1列的左侧。沿行方向再次移动该喷头并喷射包含蓝色发光材料的墨水，从而形成对应于第4行的蓝色子像素的发光层。
此外，在根据本公开的实施例中，喷头沿行方向移动时，一个喷嘴可以在对应于绿色像素的一行第一电极上喷射包含绿色发光材料的 墨水。由于对应绿色子像素的每个第一电极包含两个子电极，喷头只需要沿行方向移动一次，就可以使用单个喷嘴在对应绿色子像素的一行第一电极的每个子电极(即相邻的两行子电极)上形成绿色发光层。同理，对于对应红色子像素的第一电极的子电极，也可以通过喷头沿行方向移动一次，就可以使用单个喷嘴在对应红色子像素的一行第一电极的每个子电极(即相邻的两行子电极)上形成红色发光层。
最后，如图23E所示，在电子注入层上，形成阴极(第二电极)2309，从而得到根据本公开的实施例的显示装置。
图23F示出了按照上述方式得到的显示装置中的像素排布的示意图。如图23F所示，在上述根据本公开的实施例的显示装置中，只有第一电极与发光层重叠的部分才能发光。因此，每个蓝色子像素B的宽度(沿列方向的尺寸)等于重叠部分的宽度。蓝色发光层的宽度取决于喷头的单个喷嘴能够形成的发光材料的宽度。
另外，由于对应于红色子像素和绿色子像素的第一电极2302被分割为彼此电绝缘的两个电极23021、23022，因此每个绿色子像素G和红色子像素R的宽度(沿列方向的尺寸)可以减小为喷头的单个喷嘴能够形成的发光层与下面对应的电极23021、23022之间的重叠部分的宽度。
同现有技术中未对第一电极进行进一步分割的情况相比，可以得到更小的像素和更高的分辨率。如图23F中的虚线所示，显示装置中的一个像素2310可以包含第4行第1列的蓝色子像素B，第3行第1列中下面的红色子像素2305，以及第5行第1列中上面的绿色子像素2306。
此外，在根据本公开的实施例的显示装置中，沿列方向(第二方向)相邻的两个像素中，分别位于不同像素中的、相邻的两个发光层发出相同颜色的光。如图23F中的虚线所示，第一列中具有相邻的两个像素2310和2320。像素2310中的绿色子像素2306与像素2320中的绿色子像素2307相邻。
此外，在图23F所示的示例中，像素2310和像素2320为正方形。 但是，应当理解，本公开不限于此。基于本公开的教导，像素的形状可以由本领域技术人员根据实际需要进行选择。
采用本公开的上述技术方案，可以突破打印设备导致的分辨率上限，实现更大分辨率的显示装置。
图24示出了根据本公开的图22所述的制造方法得到的QLED显示装置的照片。如图24所示，该显示装置的分辨率达到了150ppi，而制造该QLED显示装置的喷头的物理分辨率只有100ppi。因此，使用本公开的制造方法，制造出显示分辨率超过喷头的物理分辨率的显示装置。这样，可以使用低物理分辨率的喷头，得到高分辨率的显示装置。
此外，在根据本公开的一些实施例中，每个子像素中蓝色发光层的面积大于红色发光层和绿色发光层中的一者或两者的面积。同红色发光材料和绿色发光材料相比，蓝色发光材料的稳定性比较差。因此，蓝色发光材料发出的蓝光衰减得更快，这容易导致色差问题。通过设置蓝色发光材料具有更大的面积，可以改善由于蓝光衰减导致的色差问题。
例如，在根据本公开的一个实施例中，在每个像素的发光层中，蓝色发光层的面积可以是绿色发光层的面积的2倍。此外，在根据本公开的一个实施例中，蓝色发光层的面积可以是红色发光层的面积的2倍。在根据本公开的又一个实施例中，红色发光层的面积等于绿色发光层的面积，并且蓝色发光层的面积是红色发光层面积的2倍。
图25A和图25B示出了根据本公开的实施例的制造显示装置过程中的第一电极阵列的示意图。如图25A所示，在基板上形成的第一电极阵列中，每个第一电极的形状为正方形。与上述图23C所示的实施例类似，可以进一步将与绿色子像素和红色子像素对应的第一电极分割成两个彼此电绝缘的电极，如图25B所示，第1行、第3行、第5行和第7行的第一电极被进一步分割，从而得到与单个子像素对应的各个电极。
如上所述，在显示装置工作的过程中，只有发光层中的发光材料 与第一电极重叠的部分会发光。因此，当发光层中的发光材料覆盖的面积大于第一电极的面积时，每个子像素的形状由与其对应的电极的形状决定。在图25A和图25B的实施例中，红色子像素和绿色子像素中的阳极由正方形的第一电极分割得到，因此红色子像素和绿色子像素的形状为长方形，而蓝色子像素中的阳极未被分割，因此蓝色子像素的形状为正方形。
图26示出了根据本公开的实施例的制造显示装置过程中的第一电极阵列的示意图。如图26所示，在基板上形成的第一电极阵列中，每个第一电极的形状为圆形。与上述图23C所示的实施例类似，可以进一步将与绿色子像素和红色子像素对应的第一电极分割成两个彼此电绝缘的电极，如图26所示，第1行、第3行和第5行的第一电极被进一步分割，从而得到与单个子像素对应的各个电极。
在图26的实施例中，红色子像素和绿色子像素中的阳极由圆形的第一电极分割得到，因此红色子像素和绿色子像素的形状为半圆形，而蓝色子像素中的阳极未被分割，因此蓝色子像素的形状为圆形。
应当理解，根据本公开的实施例的第一电极的形状不限于上述的长条形、正方形和圆形，也可以是其它合适的形状，例如椭圆形、菱形、三角形、六边形或其他多边形等。
下面，将结合图2-图10B进一步详细介绍根据本公开的实施例的未设置隔离结构的显示装置。应当理解，根据本公开的显示装置可以包括发光装置以及其它装置，例如电源等(未示出)。在本公开中，主要示出和描述了显示装置中的发光部分(即发光装置)的结构和特点，其它装置与现有技术相似，本公开就不再详细描述和介绍。
图2示出了根据本公开一个实施例的发光装置的示意图。如图2所示，发光装置200包括第一基板101。第一基板101上形成有多个第一电极103。发光装置200还包括位于所述多个第一电极之上的功能层的叠层(未以附图标记标示)。所述叠层至少包括发光层，发光层包括多个彼此独立的单元107。在图2所示的实施例中，所述多个单元107被示出为彼此分离。所述多个单元107被与相应的第一电极 对应地设置，例如，在一些实施方式中，单元107可以与第一电极103一一对应地设置。
在根据本实施例的发光装置中，在所述多个单元107之间没有设置从第一基板或第一电极延伸达到单元107的高度或以上从而分隔所述多个单元的隔离结构。换而言之，在本公开实施例的发光装置中，没有现有技术中的像素界定层。
在本实施例中，所述多个单元107被配置为其每一单元107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。如此，可以提高发光效率；还可以使得发光均匀。另一方面，还可以减少相邻像素(或子像素)对当前像素(或子像素)的影响。稍后将结合附图4A-4C以及5A和5B进行更详细说明。在本文中，在需要时，也可能以附图标记107来指示发光层。
在图2中，还示出了在发光层(其包括单元107)之下的下部功能层105和在发光层之上的上部功能层109。本领域技术人员将容易理解，下部功能层105或上部功能层109中的一个或多个是可选的。另外，尽管在图2中下部功能层105和上部功能层109被示出为单层，但其可以是多层。另外，尽管在图2所示的实施例中，一个或多个功能层被示出为整面形式的，也就是说，该功能层可以用于多个像素或子像素，然而在其他实施方式中，功能层也可以包括多个单元，单个单元可以用于一个或多个像素或子像素。
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、缓冲层、和/或实现其他期望功能的任意层等等。在一些实现方式中，电极或功能层可以为两个像素共享。
在图2所示的实现方式中，所述多个单元107被示出为彼此分离，上部功能层109的至少一部分位于所述多个单元107的单元与单元之间。在本实施例中，所述多个单元107被同层设置。换而言之，所述 多个单元107被设置在同一层中，厚度在工艺精度的范围内基本相同。然而在其他实施例中，能够发射不同波段的光的多个单元107的厚度也可以不同。
在一些实施例中，在发光层单元107与单元107之间，上部功能层109的至少一部分与在发光层之下的下部功能层105的未被所述发光层遮蔽的部分接触。
在一些实施例中，发光层的单元是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。在一些实施方式中，量子点可以被配置为均匀分散在墨滴中。在一些实施例中，可以对在发光层107之下的下部功能层105(或者其中的一层或多层)的一部分进行处理，以使其表面性质不同于其他部分，从而对墨滴的打印施加影响。例如，可以对下部功能层(或者其中的一层或多层)的部分表面进行紫外线处理，从而改变其亲疏水性或其它性质。然而，由于功能层通常都是对光电性质或其他属性等有要求的层且其成分复杂，这样的处理可能会造成对光电性质、化学性质或表面平坦性等产生不利的影响，从而影响器件性能。另外，通过表面亲疏处理开展图案化的工艺中，要求各层功能层的材料均具有相同的表面亲疏性，从而对功能层的材料选择更加严苛，且同时需要兼顾发光装置的光电性能。因此，在更优选的实施例中，不进行这样的处理，而是使得所述下部功能层中与所述发光层的单元重叠的部分与所述下部功能层中不与所述发光层的单元重叠的部分的表面性质一致。如此，既降低了工艺复杂度，提供了制备效率，降低了成本，又使得对器件性能的影响最小化。
图3示出了根据本公开另一实施例的发光装置的示意图。相比于图2所示的发光装置200，发光装置300还包括位于功能层的叠层之上的第二电极301。根据需要，在一些实现方式中，第二电极301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301可以被配置为允许发光层所发出的光从其透射出去。示例性地，第二电极301 的厚度可以为几百纳米，例如100nm-200nm。
发光层的所述多个单元107中的各个单元、对应的第一电极103和第二电极301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301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)。
在某些实施例中，发光装置300还可以包括设置在第二电极301之上覆盖层303。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。在一些实现方式中，覆盖层可以由有机小分子材料，通过热蒸镀工艺制作，如NPB、Alq、CBP等形成；覆盖层的厚度可以为例如，20nm-400nm。在一些实现方式中，覆盖层可以由无机材料，可通过化学气相沉积CVD、物理气相沉积PVD工艺制作，如Al 2O 3、Si xN y，Si xN yO z等；厚度可以为例如20nm-400nm。在一些实现方式中，覆盖层可以由有机无机杂化材料，通过湿法成膜工艺制作，如狭缝涂布、喷墨打印、超声喷涂、丝网印刷等；厚度可以为例如300nm-3000nm。所述有机材料可以是高分子树脂，如丙烯酸树脂、环氧树脂等，也可以选自聚甲基丙烯酸甲酯、聚环烯烃等。所述无机材料可以选自金属化合物颗粒，如氧化铝、氧化钛、氧化锆等。优选地，无机颗粒的粒径一般不超过1000nm。
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。
图4A-4C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。在该示例中，下 部电极103被示出为圆形。发光层的单元107也被示出为圆形。在俯视图中，发光层的单元107覆盖下部电极(即，第一电极)103。也就是说，发光层的单元107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，通过喷墨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4A所示，假设墨滴干燥后所形成的圆形单元107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107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。
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107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107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4B示出了发光层的相邻的两个单元107和对应的相邻的两个下部电极103。如图4B中所示，两个单元107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107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的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4C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，膜层厚度也要满足。
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5A和5B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5A和5B所示的实施例中，以长条形像素举例进行说明。
如图5A所示，墨滴打印所形成的单元107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107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107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5B示出了相邻的单元1071和1072以及对应的相邻的下部电极1031和1032的情形。各单元1071和1072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。如图5B中所示，两个单元1071和1072的宽度(横向尺寸)分别为L1和L2，打印精度分别为a1和a2，两个第一电极1031和1032的宽度(横向尺寸)分别为l1和l2。各单元1071和1072和对应的下部电极1031和1032满足在前述的配置，也 即，单元1071的半宽度L1/2大于或等于对应的第一电极1031的半宽度l1/2与打印精度a1之和(L1/2≥l1/2+a1)，单元1072的半宽度L1/2大于或等于对应的第一电极1032的半宽度l2/2与打印精度a2之和(L2/2≥l2/2+a2)。。
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1071和1072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a1＝a2＝a的情况下，间距D≥L1/2+L2/2+2a≥l1/2+l2/2+4a。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个实施例的发光装置的制备方法。图6A-6E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。
如图6A所示，提供第一基板101，其上具有多个第一电极103。第一基板101可以是TFT基板(其也可能被称作像素基板)。在此，可选地，可以对第一基板进行清洗。例如，利用清洗剂对该基板进行溶剂清洗，水洗，然后甩干，接着进行表面等离子处理待用。
接着，如图6B和6C所示，在第一基板101上形成功能层的叠层，所述叠层至少包括发光层，所述发光层包括多个单元107。所述多个单元107与相应的第一电极对应地设置。在所述多个单元107之间没有从第一基板或第一电极延伸达到所述多个单元的高度或以上从而分隔所述多个单元的隔离结构。该隔离结构在现有技术中也被称为像素界定层(PDL)。
在一些实现方式中，在所述第一基板101上形成功能层的叠层可以包括以下步骤：通过喷墨打印方法，与所述多个第一电极对应地形成与所述发光层的所述多个单元对应的液态打印单元，所述墨滴含有 量子点材料；对所述液态打印单元进行干燥，从而形成所述发光层的所述多个单元。在一些实现方式中，所述多个单元中的每一单元在第一基板上的正投影覆盖对应的第一电极在第一基板上的正投影。
在一些实现方式中，发光装置的制备方法中不包括对任意一层电极或功能层进行亲水性处理或者疏水性处理。
在一些实现方式中，可选地，如图6B所示，形成下部功能层105，所述下部功能层至少覆盖所述多个第一电极103；接着，可以同上面所述的方法在所述下部功能层上形成所述发光层的所述多个单元107。
在一些实施例中，下部功能层105可以包括空穴注入层和空穴传输层(图中未示出)。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。之后，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，打印在上述空穴注入层材料上方；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。
在制备了可选的下部功能层之后，可以在下部功能层上形成发光层。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，并将相应的下部电极区域完全覆盖；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。
之后，如图6C所示，可选地，可以采用类似的或任何适当的方法 来形成上部功能层109，所述上部功能层109覆盖所述发光层的所述多个单元107。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，如图6D所示，在所述功能层的叠层上形成第二电极301。在一些实现方式中，第二电极301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，如图6E所示，在所述第二电极上形成可以透射光的覆盖层303。
图7示出了根据本公开另一实施例的发光装置的示意图。如图7所示，发光装置700还包括间隔物(spacer)701。间隔物701设置在第二电极301的远离第一电极的一侧。间隔物701可以用于在封装时减少压力或应力对像素的影响，从而保护像素或发光单元。
这里，如前所述地，发光层的所述多个单元107中的各个单元、对应的第一电极103和第二电极301的对应的部分可以被包括在对应的像素中。还需要说明的是，本申请中所称像素，在没有相反说明的情况下，其可以包括子像素。
在发光装置700还包括可选的覆盖层303的情况下，间隔物701设置在第二电极301的远离第一电极的一侧，隔着覆盖层303与第二电极301相对。间隔物701与像素偏移地设置，从而避免遮挡发光单元发出的光，并可以避免压力或应力被传递到像素的发光单元。
尽管在图7所示的实施例中，间隔物701被示出为形成在覆盖层处，并示出为椭圆形，然而这仅仅是示例性的，本公开并无限于此。间隔物701也可以设置在对置基板(如图8中的801所示)上，其也可以采用任何期望的形状。
这里，作为示例，间隔物701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701。或者，间隔物701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。
作为示例，间隔物的厚度可以为0.5微米-5微米；形状可以是正 梯形(通过正性光刻胶进行光刻形成)或倒梯形(通过负性光刻胶进行光刻形成)；材料可以为下列中的一种或多个：聚甲基丙烯酸甲酯(PMMA)、聚苯乙烯(PS)、聚对苯二甲酸乙二醇酯(PET)、聚碳酸酯(PC)、聚酰亚胺(PI)、聚氨酯(PU)和聚氯乙烯(PVC)。
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8示出了根据本公开另一实施例的发光装置的示意图。如图8所示，相比图7所示的发光装置，发光装置800还包括对置的第二基板801。可以将第二基板801和第一基板101对置并进行封装。发光单元(所述功能层的叠层)设置在所述第一基板和第二基板之间。在第二基板801和第一基板101之间可以填充有填充材料803。
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。
下面说明根据本公开的制备显示装置的方法的一个实例。
首先，提供第一基板。所述第一基板可以是用于形成像素的像素基板，有时其也可被称为TFT基板。这里，所述第一基板可以是根据前述任意实施例或实现方式的无隔离结构的基板。
可选地，可以对第一基板进行清洗，例如利用清洗剂对第一基板进行溶剂清洗，水洗，然后甩干。接着，可以对第一基板进行表面等离子处理待用。
然后，在第一基板上形成空穴注入层。例如，可以将空穴注入材料配成适合涂布的溶液，选择适当的涂布参数，进行涂布。涂布后将基板放置在热板上，以使得涂布的溶液干燥。从而，形成空穴注入层。
之后，形成空穴传输层。例如，可以将空穴传输层材料的配成可以打印的墨水配方，将其上形成了空穴注入层的第一基板卡夹就位，通过打印设备(例如，纳米材料打印设备DMP2831)进行打印，从而将材料打印在空穴注入层上。然后可以通过真空热板对第一基板进行干燥。从而，形成空穴传输层。
之后，形成量子点(QD)层。例如，可以将QD原液通过离心沉淀后，重新分散到打印溶剂的配方，来配成可以打印的墨水装入打印设备。根据设置的打印参数，将包含QD材料的墨水精准打印在像素基板的相互独立的电极区域，并将电极区域完全覆盖。打印完成后，可以将基板转移至真空热板，进行真空干燥。如此，形成量子点层。
图10A示出了根据该实例制备的发光装置中第一基板(这里，像素基板)上打印的QD层的显微镜照片，而图10B与图10A所示的区域相应的台阶仪扫描结果。如图10B中所示，所形成的QD膜层从边缘到中间膜层基本均匀。
此外，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。
图11A示出了根据本公开一个实施例的发光装置的示意图。如图 11A所示，发光装置1200A包括第一基板1101。第一基板1101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1101上形成有多个第一电极1103以及多个隔离结构1105。隔离结构1105可以用作界定像素的像素界定层(PDL)。隔离结构1105位于第一基板1101上，并从第一基板向上延伸。隔离结构1105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1103也可被称为底电极。第一电极1103可以设置在相应的隔离结构之间。在图11A的截面图所示的示例中，仅示出了一个第一电极1103，其设置在相应的两个隔离结构1105之间。在某些实施例中，隔离结构1105的一部分可以与第一电极1103重叠。如图11A所示，第一电极1103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11A仅仅示出了发光装置的一部分的截面图，因此其基板1101和隔离结构1105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1105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11B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11A，图11B中示出了一个完整的隔离结构1105。如图11A和11B所示，根据本公开的实施例，隔离结构1105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11A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11A和11B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11A，发光装置1200A还包括功能层1201。作为示例，功能层1201可以是例如空穴注入层(HIL)，然而本公开不限于此。功能层1201形成在第一电极1103和隔离结构1105上。功能层1201通常可以整面地涂覆在基板上。而在图11A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1201的墨水被隔离结构1105截断而发生层断裂。功能层1201的位于第一电极1103上的第一部分1201_1与位于隔离结构的顶面上的第二部分1201_2断裂开。如此，可以避免由于功能层1201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1105的顶面基本平坦。优选地，隔离结构1105的顶面的高度大于功能层1201的高度。在其他实施例中，隔离结构1105的顶面可以是非平面的。
图11C示出了根据本公开一个实施例的发光装置。相比图11A所示的发光装置1200A，图11C所示的发光装置1200C还可以包括在功能层1201之上的另外的功能层1203。作为示例，功能层1203可以是例如，空穴传输层。发光装置1200C还可以包括：在功能层1203之上的发光层1205，以及在发光层1205之上的功能层1207。在一些实施例中，发光层1205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1207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11C所示的实施例中，功能层1203被示出其上表面基本平坦，也就是说其基本填充了功能层1201的第一部分1201_1和第二部分1201_2之间的高度差。功能层1203的该配置可以通过设置隔离结构1105的高度、功能层1201和1203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11A和11C中下部功能层被示出为两层，但其也可能和上部功能层1109被示出为单层，但其可以是多层。
图12A和12B示出了根据本公开一些实施例的发光装置的示意图。图12A所示的发光装置1300A具有与图11C所示的发光装置1200C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12A所示的发光装置1300A与图11C所示的发光装置1200C的不同之处在于：功能层1203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1203之后形成的发光层1205填充了该凹陷，并具有基本平坦的上表面。
图12B所示的发光装置1300B具有与图12A所示的发光装置1300A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1203之后形成的发光层1205也填充了功能层1203的上表面的凹陷。图13B所示的发光装置1300B与图12A所示的发光装置1300A的不同之处在于：发光层1205并未完全覆盖功能层1203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1205的打印的墨滴在干燥后可能仅形成在功能层1203的一部分表面上。优选地，发光层1205与第一电极1103对应地设置；另外，优选地，发光层1205在基板1101上的正投影覆盖对应的第一电极1103在基板1101上的正投影。如此，可以保证发光层1205对第一电极1103的覆盖，从而改善器件发光。
另外，如图12B所示，在该示例中，上部功能层1207与下部功能层(例如，1203)的未被发光层1205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13A和13B示出了根据本公开一些实施例的发光装置的示意图。如图13A所示，发光装置1400A包括第一基板1101。第一基板1101上形成有多个第一电极1103以及多个隔离结构1105。隔离结构1105可以用作界定像素的像素界定层(PDL)。隔离结构1105位于第一基板1101上，并从第一基板向上延伸。电极1103的至少一部分可以设置在相应的隔离结构之间。隔离结构1105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1400A还包括功能层1201。作为示例，功能层1201可以是例如空穴注入层(HIL)。功能层1201形成在第一电极1103和隔离结构1105上。功能层1201的位于第一电极1103上的第一部分1201_1 与位于隔离结构的顶面上的第二部分1201_2断裂开。
发光装置1400A还可以包括在功能层1201之上的另外的功能层1203。不同于图11C，发光装置1400A中，功能层1203也发生了断裂。功能层1203包括位于第一电极1103上方的第一部分1203_1和位于隔离结构的顶面上方的第二部分1203_2，二者彼此分离而不是连续的。作为示例，功能层1203可以是例如，空穴传输层。
图13B示出了根据另一实施例的发光装置的示意图。相比图13A所示的装置1400A，图13B所示的发光装置1400B还可以包括：在功能层1203之上的发光层1205，以及在发光层1205之上的功能层1207。在一些实施例中，发光层1205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1205的至少一部分通过打印法打印在由隔离结构1105限定的区域内。在不同的实现方式中，发光层1205也可能超出所述堆叠所形成的空间的边界。
在图14B所示的实施例中，上部功能层1207基本填充了所述堆叠所形成的空间中的凹陷(如果发光层1205未能完全填充该空间的话)。功能层1207的该配置可以通过设置隔离结构1105的高度、功能层1201和1203、发光层1205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13A和13B中，对于与图11A-12B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14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11C所示的实施例，图14所示的发光装置1500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)1501。根据需要，在一些实现方式中，第二电极1501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1501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1501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1501的厚度可以为几百纳米，例如100nm-200nm。
发光层1205、对应的第一电极1103和第二电极1501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1103、功能层的叠层中的对应部分、以及第二电极1501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1500还可以包括设置在第二电极1501之上覆盖层1503。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11A和图11C所示的实施例进一步示出了上部电极1501，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1501。这里不再进行具体说明。
图15示出了根据本公开另一实施例的发光装置的示意图。如图15所示，发光装置1600包括第一基板1101。第一基板1101上形成有多个第一电极1103以及多个隔离结构1105。隔离结构1105可以用作界定像素的像素界定层(PDL)。隔离结构1105位于第一基板1101上，并从第一基板向上延伸。电极1103的至少一部分可以设置在相应的隔离结构之间。
发光装置1600的隔离结构1105被配置为不同于图11A-图14所 示的隔离结构。在该实施例中，虽然隔离结构1105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1105的侧表面(或侧壁)上形成内凹的凹陷1611实现的。凹陷1611可以通过例如湿法蚀刻或干法蚀刻来实现。
发光装置1600还包括功能层1601。作为示例，功能层1601可以是例如空穴注入层(HIL)。功能层1601形成在第一电极1103和隔离结构1105上。功能层1601的位于第一电极1103上的第一部分1601_1与位于隔离结构的顶面上的第二部分1601_2断裂开。
在该示例中，如图所示，在隔离结构1105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1601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11A-图14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16A-16D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16A所示，提供第一基板1101，其上形成有第一电极1103。在第一基板1101上形成隔离结构材料层1701。隔离结构材料层1701覆盖第一基板1101和第一电极1103。作为示例，隔离结构材料层1701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1703。掩模1703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16B所示，使所述第一基板1101和要用于对隔离结构材料层1701进行蚀刻的离子或等离子流1707的方向成一定角度。例如，在图17B所示的实施例中可以将其上形成了掩模图案的第一基板1101放置在承载台(未示出)上卡扣就位，使其相对于旋转轴1705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1101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1707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1101绕旋转轴1705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1101绕旋转轴1705旋转到如图16C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1101绕旋转轴1705旋转到如图16C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16D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1703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15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18示出了根据本公开另一实施例的发光装置的示意图。如图18所示，发光装置1900可以包括第一基板1901和对置的第二基板1905。第一基板1901上可以形成有多个像素1903。像素1903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1905上形成有多个间隔物1907。第一基板1901和第二基板1905通过封装料1911进行包封，在第一基板1901和第二基板1905之间可以填充有填充剂1909。尽管这里间隔物1907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1907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1907。或者，间隔物1907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。
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，该基板上具有由多个长条形的第一电极构成的第一电极阵列。长条形的第一电极沿行方向(第一方向)的尺寸大于沿列方向(第二方向)的尺寸。在该示例性实施例中，行方向和列方向被示出为彼此垂直，但是应当理解，本公开不限于此，只要行方向和列方向相交即可。
。作为示例，采用其上形成了ITO透明电极(作为第一电极)的玻璃基板。
之后，通过刻蚀的方式，沿行方向将对应于红色子像素和绿色子像素的第一电极进一步分割为彼此电绝缘的两个子电极。刻蚀的线宽(分割第一电极得到的两个子电极之间的间隔)可以控制在例如1微米-10微米。但应理解，本公开不限于此。
之后，在基板上形成高度大约为2微米的隔离结构。
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～485 nm)。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。在喷头沿行方向移动时，一个喷嘴可以在对应于绿色像素的一行第一电极上喷射包含绿色发光材料的墨水。由于对应绿色子像素的每个第一电极包含两个子电极，喷头只需要沿行方向移动一次，就可以使用单个喷嘴在对应绿色子像素的一行第一电极的每个子电极(即相邻的两行子电极)上形成绿色发光层。同理，对于对应红色子像素的第一电极的子电极，也可以通过喷头沿行方向移动一次，就可以使用单个喷嘴在对应红色子像素的一行第一电极的每个子电极(即相邻的两行子电极)上形成红色发光层。
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。
图24示出了根据本公开的实例1的QLED器件点亮的显微镜照片图。实例1中利用物理分辨率为100ppi的喷头进行打印制作，得到的QLED器件的分辨率为150ppi，每一个像素大小为169.33×169.33微米，且每个像素包括中间的未分割的蓝色子像素和紧邻蓝色像素的被分割的红绿子像素，其中蓝色子像素长139.33微米，宽50微米，长宽比2.79；红绿子像素长139.33微米，宽度9.67微米，长宽比14.41。从图24中可以看出，各个子像素发光均匀，无串色，较好的实现用低分辨率的喷头打印高分辨率的显示基板，降低了打印的难度，提高了良率。
实例2：
该实例2制备根据本公开的一些实施例的具有矮隔离结构的发光装置。
在该实例2中，与实例1的区别之一在于基板具有大于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。
此外，该实例2的目的在于说明根据本公开的矮隔离结构的技术效果，因此实例2与实例1的另一个区别在于：各个子像素的电极和发光层采用现有技术的传统结构和传统的喷墨打印方式制作。也就是说，在实例2中，各个第一电极没有进一步被分割为两个子电极。
作为实例3-4，使用与上述实例2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2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2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2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2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19A和19B示出了根据本公开上述实例2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2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19A的显微镜照片看，无边缘推积现象。从图19B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20A-20D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20A-20D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21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27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2的区别仅在于隔离结构的高度为200nm。如图27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28示出了根据本公开实例4的QLED的台阶仪测量结果。在该实例4中，与实例2的区别仅在于隔离结构的高度为600nm。如图28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17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2的区别仅在于隔离结构的高度为1000nm。如图17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。
在说明书及权利要求中的词语“前”、“后”、“顶”、“底”、“之上”、“之下”等，如果存在的话，用于描述性的目的而并不一定用于描述不变的相对位置。应当理解，这样使用的词语在适当的情况下是可互换的，使得在此所描述的本公开的实施例，例如，能够在与在此所示出的或另外描述的那些取向不同的其他取向上操作。
如在此所使用的，词语“示例性的”意指“用作示例、实例或说明”，而不是作为将被精确复制的“模型”。在此示例性描述的任意实现方式并不一定要被解释为比其它实现方式优选的或有利的。而且，本公开不受在上述技术领域、背景技术、发明内容或具体实施方式中所给出的任何所表述的或所暗示的理论所限定。
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。
在本公开中，术语“提供”从广义上用于涵盖获得对象的所有方式，因此“提供某对象”包括但不限于“购买”、“制备/制造”、“布置/设置”、“安装/装配”、和/或“订购”对象等。
本领域技术人员应当意识到，在上述操作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 (24)

  1. 一种制造显示装置的方法，包括：
    提供基板，在所述基板上具有由分别对应于蓝色子像素、绿色子像素和红色子像素的多个第一电极构成的第一电极阵列，所述第一电极阵列包括沿第一方向的多个行以及沿与所述第一方向相交的第二方向的多个列，每行中的所述第一电极对应于相同颜色的子像素，对应于红色子像素和绿色子像素的所述第一电极各自包含沿所述第二方向彼此间隔且电绝缘的两个相邻的子电极，所述子电极沿所述第一方向的尺寸与沿所述第二方向的尺寸的比值为大于1，相邻的两个所述子电极分别位于不同的像素中；
    沿所述第一方向移动打印喷头的同时，使所述打印喷头喷射包含发光材料的墨水，以在所述第一电极上形成发光层，其中，所述打印喷头的单个喷嘴喷射墨水至所述两个相邻的子电极上，同时形成两个相同颜色的子像素的发光层；以及
    在所述发光层上形成第二电极，
    其中，每个像素的所述发光层至少包含对应于所述红色子像素的红色发光层、对应于所述蓝色子像素的蓝色发光层和对应于所述绿色子像素的绿色发光层，并且在每个所述像素的所述发光层中，沿所述第二方向，所述蓝色发光层位于所述红色发光层与所述绿色发光层之间。
  2. 根据权利要求1所述的方法，其中，形成所述发光层的步骤包括：
    所述打印喷头沿所述第一方向移动并喷射所述墨水，形成所述发光层的相邻的多个行。
  3. 根据权利要求1所述的方法，其中，形成所述发光层的步骤包括：
    所述打印喷头沿所述第一方向移动并喷射所述墨水，形成所述发光层的多个第一行；以及
    所述打印喷头沿所述第二方向偏移预定距离后，使所述打印喷头沿 所述第一方向移动并喷射所述墨水，形成所述发光层的多个第二行。
  4. 根据权利要求1所述的方法，其中，在每个所述像素的所述发光层中，所述蓝色发光层的面积大于所述红色发光层和所述绿色发光层中任一者或两者的面积。
  5. 根据权利要求4所述的方法，其中，在每个所述像素的所述发光层中，所述蓝色发光层的面积是所述绿色发光层的面积的2倍。
  6. 根据权利要求4所述的方法，其中，在每个所述像素的所述发光层中，所述蓝色发光层的面积是所述红色发光层的面积的2倍。
  7. 根据权利要求1所述的方法，其中，所述第一电极的形状为长条形、正方形、圆形或椭圆形。
  8. 根据权利要求1所述的方法，其中，所述子电极的形状为长条形，并且所述长条形沿所述第一方向的尺寸与所述长条形沿所述第二方向的尺寸的比值为1.5-30。
  9. 根据权利要求1所述的方法，还包括：
    形成多个隔离结构，位于所述基板之上并从所述基板向上延伸，所述多个第一电极中的每一个的至少一部分设置在相应的所述隔离结构之间。
  10. 根据权利要求9所述的方法，其中，所述隔离结构的高度小于700nm。
  11. 根据权利要求9所述的方法，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叠层中紧邻所述第一电极的所述功能层的高度，所述功能层的叠层至少位于所述第一电极之上，所述叠层至少包括位于所述第一电极上的第一功能层和在所述第一功能层之上的所述发光层。
  12. 根据权利要求1所述的方法，其中，未设置有从所述基板或所述第一电极延伸至所述发光层的高度或以上从而分隔所述发光层的隔离结构。
  13. 根据权利要求1所述的方法，其中，分割所述第一电极得到的两个所述子电极之间的间隔为1微米-10微米。
  14. 一种显示装置，包括：
    基板；
    位于所述基板上的、由分别对应于蓝色子像素、绿色子像素和红色子像素的多个第一电极构成的第一电极阵列，所述第一电极阵列包括沿第一方向的多个行以及沿与所述第一方向相交的第二方向的多个列，每行中的所述第一电极对应于相同颜色的子像素，对应于所述红色子像素和所述绿色子像素的所述第一电极各自包含沿所述第二方向彼此间隔且电绝缘的两个相邻的子电极，所述子电极沿所述第一方向的尺寸与沿所述第二方向的尺寸的比值为大于1；
    位于所述第一电极阵列上的发光层，至少包含对应所述红色子像素的红色发光层、对应所述蓝色子像素的蓝色发光层和对应所述绿色子像素的绿色发光层；
    位于所述发光层上的第二电极；
    在每个像素的所述发光层中，沿所述第二方向，所述蓝色发光层位于所述红色发光层与所述绿色发光层之间；
    对于沿所述第二方向相邻的两个像素，分别位于不同像素中的相邻的两个所述发光层发出相同颜色的光。
  15. 根据权利要求14所述的显示装置，其中，在每个所述像素的所述发光层中，所述蓝色发光层的面积大于所述红色发光层和所述绿色发光层中任一者或两者的面积。
  16. 根据权利要求15所述的显示装置，其中，在每个所述像素的所述发光层中，所述蓝色发光层的面积是所述绿色发光层的面积的2倍。
  17. 根据权利要求15所述的显示装置，其中，在每个所述像素的所述发光层中，所述蓝色发光层的面积是所述红色发光层的面积的2倍。
  18. 根据权利要求14所述的显示装置，其中，所述第一电极的形状为长条形、正方形、圆形或椭圆形。
  19. 根据权利要求14所述的显示装置，其中，所述子电极的形状为长条形，并且所述长条形沿所述第一方向的尺寸与所述长条形沿所述第二方向的尺寸的比值为1.5-30。
  20. 根据权利要求14所述的显示装置，其中，每个所述像素包括沿所述第二方向排列的所述红色子像素、所述绿色子像素和所述蓝色子像素，每个所述像素的形状为正方形。
  21. 根据权利要求14所述的显示装置，还包括：
    多个隔离结构，位于所述基板之上并从所述基板向上延伸，所述多个第一电极中的每一个的至少一部分设置在相应的所述隔离结构之间。
  22. 根据权利要求21所述的显示装置，其中，所述隔离结构的高度小于700nm。
  23. 根据权利要求21所述的显示装置，还包括：所述功能层的叠层，其中所述功能层包括所述发光层，
    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所述叠层的高度与200纳米之和，且不低于紧邻所述隔离结构的所述叠层中紧邻所述第一电极的所述功能层的高度。
  24. 根据权利要求21所述的显示装置，其中，未设置有从所述基板或所述第一电极延伸至所述发光层的高度或以上从而分隔所述发光层的所述隔离结构。
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KR20060055098A (ko) * 2004-11-18 2006-05-23 삼성에스디아이 주식회사 디스플레이 장치
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CN105552102A (zh) * 2015-12-23 2016-05-04 昆山国显光电有限公司 像素排布结构及其制造方法，显示器
CN105742311A (zh) * 2014-12-11 2016-07-06 昆山国显光电有限公司 一种显示装置及其制备方法
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