Display device, display substrate and manufacturing method thereof

Abstract

The embodiment of the present invention provides a display device, a display substrate and a preparation method thereof, which relates to the field of display technology, so as to reduce the cleaning frequency of FMM and reduce the risk of poor color mixing of products. The display substrate includes a substrate and a plurality of sub-pixels, each sub-pixel includes a transparent first electrode and a second electrode located on a side of the first electrode away from the substrate; wherein the first sub-pixel also includes: a first reflection layer located between the substrate and the first electrode, a first insulating layer located between the first reflection layer and the first electrode, a first buffer pattern and a first light-emitting pattern located between the first electrode and the second electrode; the second sub-pixel also includes: a second reflection layer located between the substrate and the first electrode, a second buffer pattern and a second light-emitting pattern located between the first electrode and the second electrode; the third sub-pixel also includes: a third reflection layer located between the substrate and the first electrode, a third buffer pattern and a third light-emitting pattern located between the first electrode and the second electrode.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display device, a display substrate and a preparation method thereof. Background Art

[0002] Electroluminescent display devices are widely used in smart products such as mobile phones, televisions, and laptops due to their advantages of self-luminescence, low power consumption, wide viewing angle, fast response speed, and high contrast. In addition, electroluminescent display devices have become the research focus of many scholars at home and abroad due to their light weight, thin thickness, and anti-bending performance.

[0003] like Figure 1 As shown, the main structure of the electroluminescent display device includes an anode 01, a hole injection layer 02, a hole transport layer 03, a buffer layer 04, a light-emitting layer 05, a hole blocking layer 06, an electron transport layer 07, an electron injection layer 08 and a cathode 09 stacked in sequence. When a voltage is applied to the anode 01 and the cathode 09, the holes generated by the anode 01 and the electrons generated by the cathode 09 recombine and release light in the light-emitting layer 05. Depending on the material of the light-emitting layer 05 and the excitation energy, photons of different energies can be emitted, corresponding to light of different colors. In detail, the light-emitting layer 05 includes a red light-emitting layer 051, a green light-emitting layer 052 and a blue light-emitting layer 053. The light emitted by the red light-emitting layer 051, the green light-emitting layer 052 and the blue light-emitting layer 053 is emitted from the cathode 09 side. The materials and thicknesses of the buffer layer 04 under the light-emitting layers 05 of different colors are different. The buffer layer 04 mainly plays the role of energy level matching and electron blocking.

[0004] However, in the process of preparing the above-mentioned electroluminescent display device using the evaporation process, since the overall thickness of the red light-emitting layer and the buffer layer thereunder and the overall thickness of the green light-emitting layer and the buffer layer thereunder are relatively thick, the red light-emitting layer and the buffer layer thereunder need to be evaporated twice in different chambers using a fine metal mask (FMM for short), and the green light-emitting layer and the buffer layer thereunder need to be evaporated twice in different chambers using an FMM. Such a process flow requires a large number of organic chambers and FMMs for the evaporation equipment used, and the cost is relatively high. At the same time, during the evaporation of the light-emitting layer and the buffer layer, the corresponding FMMs need to be aligned, and the two alignments are likely to cause poor color mixing of the product. Summary of the invention

[0005] The embodiments of the present invention provide a display device, a display substrate and a method for manufacturing the same, so as to reduce the cleaning frequency of FMM and the risk of poor color mixing of products at a low cost.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] In a first aspect, the present invention provides a display substrate, comprising: a substrate; a plurality of sub-pixels arranged on the substrate, the plurality of sub-pixels comprising: a first sub-pixel, a second sub-pixel and a third sub-pixel having different luminous colors, each sub-pixel comprising a transparent first electrode and a second electrode located on a side of the first electrode away from the substrate; wherein the first sub-pixel further comprises: a first reflective layer located between the substrate and the first electrode, a first insulating layer located between the first reflective layer and the first electrode, a first buffer pattern and a first luminous pattern located between the first electrode and the second electrode; the second sub-pixel further comprises: a second reflective layer located between the substrate and the first electrode, a second buffer pattern and a second luminous pattern located between the first electrode and the second electrode; the third sub-pixel further comprises: a third reflective layer located between the substrate and the first electrode, a third buffer pattern and a third luminous pattern located between the first electrode and the second electrode.

[0008] In some embodiments, the second sub-pixel further includes: a second insulating layer located between the second reflective layer and the first electrode; and / or the third sub-pixel further includes: a third insulating layer located between the third reflective layer and the first electrode.

[0009] In some embodiments, when the second sub-pixel includes the second insulating layer and the third sub-pixel includes the third insulating layer, the first insulating layer, the second insulating layer, and the third insulating layer have the same thickness.

[0010] In some embodiments, the first reflective layer, the second reflective layer and the third reflective layer belong to the same layer; the first insulating layer, the second insulating layer and the third insulating layer belong to the same layer, and the first insulating layer, the second insulating layer and the third insulating layer are connected.

[0011] In some embodiments, when the second subpixel includes a second insulating layer and the third subpixel includes a third insulating layer, the thickness of the first insulating layer is greater than that of the second insulating layer, and the thickness of the second insulating layer is greater than that of the third insulating layer.

[0012] In some embodiments, the first insulating layer includes: a first insulating sublayer, a second insulating sublayer, and a third insulating sublayer stacked in sequence in a direction away from the substrate; the second insulating layer includes: a fourth insulating sublayer and a fifth insulating sublayer stacked in sequence in a direction away from the substrate; wherein the third insulating sublayer, the fifth insulating sublayer, and the third insulating layer belong to the same layer, and the third insulating sublayer, the fifth insulating sublayer, and the third insulating layer are connected; the second insulating sublayer and the fourth insulating sublayer belong to the same layer, and the second insulating sublayer and the fourth insulating sublayer are connected.

[0013] In some embodiments, the surface of the first buffer pattern close to the first light-emitting pattern contacts the surface of the first light-emitting pattern close to the first buffer pattern, and the projections of the two on the substrate completely overlap; the surface of the second buffer pattern close to the second light-emitting pattern contacts the surface of the second light-emitting pattern close to the second buffer pattern, and the projections of the two on the substrate completely overlap; the surface of the third buffer pattern close to the third light-emitting pattern contacts the surface of the third light-emitting pattern close to the third buffer pattern, and the projections of the two on the substrate completely overlap.

[0014] The display substrate provided by the present invention comprises a substrate and a plurality of sub-pixels arranged on the substrate, each sub-pixel comprises a transparent first electrode and a second electrode located on a side of the first electrode away from the substrate. The plurality of sub-pixels comprises a first sub-pixel, a second sub-pixel and a third sub-pixel with different luminous colors, the first sub-pixel comprises a first reflection layer located between the substrate and the first electrode, a first insulating layer located between the first reflection layer and the first electrode, a first buffer pattern and a first luminous pattern located between the first electrode and the second electrode; the second sub-pixel comprises a second reflection layer located between the substrate and the first electrode, a second buffer pattern and a second luminous pattern located between the first electrode and the second electrode; the third sub-pixel comprises a third reflection layer located between the substrate and the first electrode, a third buffer pattern and a third luminous pattern located between the first electrode and the second electrode. Here, the second electrode is translucent, that is, the light emitted from the side of the second electrode close to the substrate partially transmits through the second electrode and is partially reflected by the second electrode. At this time, since the first electrode is transparent, and a first reflective layer, a second reflective layer and a third reflective layer are provided between the first electrode and the substrate, the cavity length of the first sub-pixel is the distance between the first reflective layer and the second electrode, the cavity length of the second sub-pixel is the distance between the second reflective layer and the second electrode, and the cavity length of the third sub-pixel is the distance between the third reflective layer and the second electrode. Compared with the prior art, the display substrate provided by the present invention has a cavity length of the first sub-pixel, the second sub-pixel and the third sub-pixel that increases the thickness of the transparent first electrode, so that the overall thickness of the first buffer pattern and the first light-emitting pattern, the second buffer pattern and the second light-emitting pattern, and the third buffer pattern and the third light-emitting pattern can be reduced, and the cleaning frequency of the corresponding FMM can be reduced; in addition, a first insulating layer is also provided between the first reflective layer and the first electrode, so that the requirement of the first sub-pixel for the cavity length can be met by adjusting the thickness of the first insulating layer, and the thickness of the first buffer pattern and the first light-emitting pattern is thinner, so that the first buffer pattern and the first light-emitting pattern can share a FMM in a chamber for evaporation, reducing the risk of poor color mixing of the product and reducing costs.

[0015] In a second aspect, the present invention also provides a method for preparing a display substrate, comprising: arranging a plurality of sub-pixels on a substrate, the plurality of sub-pixels comprising: a first sub-pixel, a second sub-pixel and a third sub-pixel having different luminous colors, each sub-pixel comprising a transparent first electrode and a second electrode located on a side of the first electrode away from the substrate; wherein the first sub-pixel further comprises: a first reflective layer located between the substrate and the first electrode, a first insulating layer located between the first reflective layer and the first electrode, a first buffer pattern and a first luminous pattern located between the first electrode and the second electrode; the second sub-pixel further comprises: a second reflective layer located between the substrate and the first electrode, a second buffer pattern and a second luminous pattern located between the first electrode and the second electrode; the third sub-pixel further comprises: a third reflective layer located between the substrate and the first electrode, a third buffer pattern and a third luminous pattern located between the first electrode and the second electrode.

[0016] In some embodiments, arranging a plurality of sub-pixels on a substrate comprises: forming a first reflective layer, a second reflective layer, and a third reflective layer on the substrate; forming an insulating film covering the first reflective layer, the second reflective layer, and the third reflective layer; forming a first electrode layer on the substrate formed with the insulating film, the first electrode layer comprising a plurality of first electrodes; wherein a portion of the insulating film located between the first reflective layer and a first electrode is the first insulating layer, a portion of the insulating film located between the second reflective layer and a first electrode is the second insulating layer, and a portion of the insulating film located between the third reflective layer and a first electrode is the third insulating layer; forming a first buffer pattern and a first light-emitting pattern belonging to the first sub-pixel, a second buffer pattern and a second light-emitting pattern belonging to the second sub-pixel, and a third buffer pattern and a third light-emitting pattern belonging to the third sub-pixel on the substrate formed with the first electrode layer; forming a second electrode layer, a portion of the second electrode layer corresponding to a sub-pixel is a second electrode.

[0017] In some embodiments, arranging a plurality of sub-pixels on a substrate comprises: forming a first reflective layer belonging to a first sub-pixel on the substrate; forming a first insulating film covering the first reflective layer; forming a second reflective layer belonging to a second sub-pixel on the first insulating film; forming a second insulating film covering the second reflective layer; forming a third reflective layer belonging to a third sub-pixel on the second insulating film; forming a third insulating film covering the third reflective layer; forming a first electrode layer on the substrate formed with the first insulating film, the second insulating film and the third insulating film, the first electrode layer comprising a plurality of first electrodes; wherein a portion of the first insulating film, the second insulating film and the third insulating film located between the first reflective layer and a first electrode is the first insulating layer, a portion of the second insulating film and the third insulating film located between the second reflective layer and a first electrode is the second insulating layer, and a portion of the third insulating film located between the third reflective layer and a first electrode is the third insulating layer; forming a first buffer pattern and a first light-emitting pattern belonging to the first sub-pixel, a second buffer pattern and a second light-emitting pattern belonging to the second sub-pixel, and a third buffer pattern and a third light-emitting pattern belonging to the third sub-pixel on the substrate formed with the first electrode layer; forming a second electrode layer, a portion of the second electrode layer corresponding to a sub-pixel is a second electrode.

[0018] Compared with the prior art, the beneficial effects of the method for preparing a display substrate provided by the present invention are the same as the beneficial effects of the display substrate provided by the above technical solution, and will not be elaborated herein.

[0019] In a third aspect, the present invention further provides a display device, comprising the above-mentioned display substrate.

[0020] Compared with the prior art, the beneficial effects of the display device provided by the present invention are the same as the beneficial effects of the display substrate provided by the above technical solution, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic structural diagram of a display substrate in the prior art;

[0023] Figure 2 A schematic diagram of a display substrate provided in an embodiment of the present invention Figure 1 ;

[0024] Figure 3A schematic diagram of a display substrate provided in an embodiment of the present invention Figure 2 ;

[0025] Figure 4 A schematic diagram of a display substrate provided in an embodiment of the present invention Figure 3 ;

[0026] Figure 5 A schematic diagram of a display substrate provided in an embodiment of the present invention Figure 4 ;

[0027] Figure 6 A partial cross-sectional view of a display substrate at a first sub-pixel provided by an embodiment of the present invention;

[0028] Figure 7 The steps of a method for preparing a display substrate provided by an embodiment of the present invention are as follows: Figure 1 ;

[0029] Figure 8 The steps of a method for preparing a display substrate provided by an embodiment of the present invention are as follows: Figure 2 ;

[0030] Fig. 9 A schematic diagram of a method for preparing a display substrate according to an embodiment of the present invention Figure 1 ;

[0031] Fig.10 A schematic diagram of a method for preparing a display substrate according to an embodiment of the present invention Figure 2 .

[0032] Reference numerals:

[0033] 01-anode; 02-hole injection layer; 03-hole transport layer; 04-buffer layer; 05-light-emitting layer; 051-red light-emitting layer; 052-green light-emitting layer; 053-blue light-emitting layer; 06-hole blocking layer; 07-electron transport layer; 08-electron injection layer; 09-cathode; 10-substrate; 11-pixel defining layer; 12-substrate substrate; 13-flat layer; 14-driving transistor; 20-first sub-pixel; 21-first reflective layer; 22-first insulating layer; 23-first A buffer pattern; 24-a first light-emitting pattern; 30-a second sub-pixel; 31-a second reflective layer; 32-a second buffer pattern; 33-a second light-emitting pattern; 34-a second insulating layer; 40-a third sub-pixel; 41-a third reflective layer; 42-a third buffer pattern; 43-a third light-emitting pattern; 44-a third insulating layer; 50-a first electrode; 60-a second electrode; 70-a light extraction layer; 80-an electron transport layer; 90-an electron injection layer; 100-a hole transport layer; 110-a hole injection layer. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The embodiment of the present invention further provides a display substrate, such as Figure 2 and Figure 4 As shown or Figure 3 and Figure 5 As shown, it includes: a substrate 10; a plurality of sub-pixels arranged on the substrate 10, the plurality of sub-pixels include: a first sub-pixel 20, a second sub-pixel 30 and a third sub-pixel 40 with different luminous colors, each sub-pixel includes a transparent first electrode 50 and a second electrode 60 located on a side of the first electrode 50 away from the substrate 10; wherein the first sub-pixel 20 also includes: a first reflective layer 21 located between the substrate 10 and the first electrode 50, a first insulating layer 22 located between the first reflective layer 21 and the first electrode 50, a first buffer pattern 23 and a first luminous pattern 24 located between the first electrode 50 and the second electrode 60; the second sub-pixel 30 also includes: a second reflective layer 31 located between the substrate 10 and the first electrode 50, a second buffer pattern 32 and a second luminous pattern 33 located between the first electrode 50 and the second electrode 60; the third sub-pixel 40 also includes: a third reflective layer 41 located between the substrate 10 and the first electrode 50, a third buffer pattern 42 and a third luminous pattern 43 located between the first electrode 50 and the second electrode 60.

[0036] The second electrode 60 is semi-transparent, that is, light emitted from the side of the second electrode 60 close to the substrate 10 partially transmits through the second electrode 60 and partially is reflected by the second electrode 60. At this time, since the first electrode 50 is transparent, and the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 are provided between the first electrode 50 and the substrate 10, the cavity length of the first sub-pixel 20 is the distance between the first reflective layer 21 and the second electrode 60, the cavity length of the second sub-pixel 30 is the distance between the second reflective layer 31 and the second electrode 60, and the cavity length of the third sub-pixel 40 is the distance between the third reflective layer 41 and the second electrode 60. Compared with the prior art, in the display substrate provided by the present invention, the cavity lengths of the first sub-pixel 20, the second sub-pixel 30 and the third sub-pixel 40 are increased by the thickness of the transparent first electrode 50, so that the overall thickness of the first buffer pattern 23 and the first light-emitting pattern 24, the second buffer pattern 32 and the second light-emitting pattern 33, and the third buffer pattern 42 and the third light-emitting pattern 43 can be reduced, and the cleaning frequency of the corresponding FMM can be reduced; in addition, a first insulating layer 22 is also provided between the first reflective layer 21 and the first electrode 50, so that the cavity length requirement of the first sub-pixel 20 can be met by adjusting the thickness of the first insulating layer 22, and the thickness of the first buffer pattern 23 and the first light-emitting pattern 24 can be made thinner, thereby satisfying that the first buffer pattern 23 and the first light-emitting pattern 24 share a FMM for evaporation in one chamber, thereby reducing the risk of poor color mixing of the product and reducing costs.

[0037] There is no limitation on the luminous color of the first sub-pixel 20, the luminous color of the second sub-pixel 30, and the luminous color of the third sub-pixel 40. For example, the luminous color of the first sub-pixel 20 is red, the luminous color of the second sub-pixel 30 is green, and the luminous color of the third sub-pixel 40 is blue. On this basis, if the cavity lengths of the first sub-pixel 20, the second sub-pixel 30, and the third sub-pixel 40 are the same, the brightness of the light actually emitted by the first sub-pixel 20, the second sub-pixel 30, and the third sub-pixel 40 will be different from the preset brightness. Based on this, when designing a display substrate, the cavity lengths of the first sub-pixel 20, the second sub-pixel 30, and the third sub-pixel 40 should be different.

[0038] Here, in order to meet the cavity length requirement of the second sub-pixel 30 and ensure that the overall thickness of the second buffer pattern 32 and the second light-emitting pattern 33 is relatively thin, in some embodiments, the second sub-pixel 30 also includes a second insulating layer 34 located between the second reflective layer 31 and the first electrode 50. In this way, the cavity length requirement of the second sub-pixel 30 can be met by adjusting the thickness of the second insulating layer 34, and the thickness of the second buffer pattern 32 and the second light-emitting pattern 33 is made thinner, thereby reducing the cleaning frequency of the corresponding FMM, reducing the material and evaporation time of the second buffer pattern 32 and the second light-emitting pattern 33, and reducing the manufacturing cost.

[0039] In order to meet the cavity length requirement of the third sub-pixel 40 and ensure that the overall thickness of the third buffer pattern 42 and the third light-emitting pattern 43 is relatively thin, in some embodiments, the third sub-pixel 40 also includes a third insulating layer 44 located between the third reflective layer 41 and the first electrode 50. In this way, the cavity length requirement of the third sub-pixel 40 can be met by adjusting the thickness of the third insulating layer 44, and the thickness of the third buffer pattern 42 and the third light-emitting pattern 43 is made thinner, thereby reducing the cleaning frequency of the corresponding FMM, reducing the material and evaporation time of the third buffer pattern 42 and the third light-emitting pattern 43, and reducing the manufacturing cost.

[0040] Furthermore, in order to ensure that the first buffer pattern 23 and the first light-emitting pattern 24 can share a FMM for vapor deposition in one chamber, in some embodiments, the surface of the first buffer pattern 23 close to the first light-emitting layer is in contact with the surface of the first light-emitting layer close to the first buffer layer, and the projections of the two on the substrate 10 completely overlap; in this way, the first buffer pattern 23 and the first light-emitting pattern 24 can be obtained by vapor deposition in one chamber using the same FMM, thereby reducing the number of chambers and FMMs required and reducing costs; at the same time, the first buffer pattern 23 and the first light-emitting pattern 24 only need to be aligned with the FMM once, thereby reducing the risk of poor color mixing of the product.

[0041] Similarly, in order to ensure that the second buffer pattern 32 and the second light-emitting pattern 33 can share a FMM for vapor deposition in one chamber, in some embodiments, the surface of the second buffer pattern 32 close to the second light-emitting pattern 33 is in contact with the surface of the second light-emitting pattern 33 close to the second buffer pattern 32, and the projections of the two on the substrate 10 completely overlap; in this way, the second buffer pattern 32 and the second light-emitting pattern 33 can be obtained by vapor deposition in one chamber using the same FMM, thereby reducing the number of chambers and FMMs required and reducing costs; at the same time, the second buffer pattern 32 and the second light-emitting pattern 33 only need to be aligned with the FMM once, thereby reducing the risk of poor color mixing of the product.

[0042] Similarly, in order to ensure that the third buffer pattern 42 and the third light-emitting pattern 43 can share a FMM for vapor deposition in one chamber, in some embodiments, the surface of the third buffer pattern 42 close to the third light-emitting pattern 43 is in contact with the surface of the third light-emitting pattern 43 close to the third buffer pattern 42, and the projections of the two on the substrate 10 completely overlap; in this way, the third buffer pattern 42 and the third light-emitting pattern 43 can be obtained by vapor deposition in one chamber using the same FMM, thereby reducing the number of chambers and FMMs required and reducing costs; at the same time, the third buffer pattern 42 and the third light-emitting pattern 43 only need to be aligned with the FMM once, thereby reducing the risk of poor color mixing of the product.

[0043] Here, the thickness of the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 is not limited. In some embodiments, the thickness of the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 ranges from 0 nm to 100 nm. Here, the insulating layer with a thickness of 0 nm represents that the cavity length of the sub-pixel is shorter, and the overall thickness of the buffer pattern and the light-emitting pattern of the sub-pixel is thin enough to meet the basic requirements without adding an insulating layer. Exemplarily, the thickness of the first insulating layer 22 can be 100 nm, the thickness of the second insulating layer 34 can be 50 nm, and the thickness of the third insulating layer 44 can be 10 nm.

[0044] There is no limitation on the materials of the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44. In some embodiments, the materials of the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 are transparent organic or inorganic insulating materials. For example, the materials of the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 can be any one of polyimide, epoxy resin, silicon nitride, silicon oxide or silicon oxynitride.

[0045] In addition, the surfaces of the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 away from the substrate 10 can be flat. At this time, the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 can be called a planarization layer (PLN for short), so that the first electrode 50 can be made on a flat surface.

[0046] In the case where the second sub-pixel 30 includes the second insulating layer 34 and the third sub-pixel 40 includes the third insulating layer 44 , the distribution of the first insulating layer 22 , the second insulating layer 34 and the third insulating layer 44 is not unique.

[0047] In some embodiments, Figure 2 and Figure 4As shown, the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 have the same thickness. The first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 belong to the same layer; the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 belong to the same layer, and the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 are connected. In this way, the first insulating layer 22, the second insulating layer 34 and the third insulating layer 44 are made in the same layer, and an insulating film covering the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 is formed at one time by a coating process. The portion of the insulating film located between the first reflective layer 21 and a first electrode 50 is the first insulating layer 22, the portion of the insulating film located between the second reflective layer 31 and a first electrode 50 is the second insulating layer 34, and the portion of the insulating film located between the third reflective layer 41 and a first electrode 50 is the third insulating layer 44, and the process is simple.

[0048] In other embodiments, Figure 3 and Figure 5 As shown, the thickness of the first insulating layer 22 is greater than the thickness of the second insulating layer 34, and the thickness of the second insulating layer 34 is greater than the thickness of the third insulating layer 44. In this way, when the luminous color of the first sub-pixel 20 is red light, the luminous color of the second sub-pixel 30 is green light, and the luminous color of the third sub-pixel 40 is blue light, the thickness of the first buffer pattern 23 belonging to the first sub-pixel 20 and the thickness of the second buffer pattern 32 belonging to the second sub-pixel 30 can be consistent with the thickness of the third buffer pattern 42 of the third sub-pixel 40, and both are relatively thin, which can reduce the material and evaporation time of the buffer layer, which is conducive to evaporation using a common FMM in one chamber, and the cost is low.

[0049] Further, the first insulating layer 22 includes: a first insulating sublayer, a second insulating sublayer, and a third insulating sublayer stacked in sequence in a direction away from the substrate 10; the second insulating layer 34 includes: a fourth insulating sublayer and a fifth insulating sublayer stacked in sequence in a direction away from the substrate 10; wherein the third insulating sublayer, the fifth insulating sublayer, and the third insulating layer 44 belong to the same layer, and the third insulating sublayer, the fifth insulating sublayer, and the third insulating layer 44 are connected; the second insulating sublayer and the fourth insulating sublayer belong to the same layer, and the second insulating sublayer and the fourth insulating sublayer are connected. In this case, the third insulating sublayer, the fifth insulating sublayer, and the third insulating layer 44 can be formed at one time using a coating process, and the second insulating sublayer and the fourth insulating sublayer can be formed at one time using a coating process, and the process is simple.

[0050] It should be noted that the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 may be continuous, that is, the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 are a whole layer, or may be disconnected, and there is no limitation on this. In some embodiments, the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 completely overlap with the projection of the first electrode 50 on the substrate 10. In this case, when the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 are arranged in the same layer, the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 may use the same FMM as the first electrode 50.

[0051] Those skilled in the art should understand that Figure 4 and Figure 6 As shown, a pixel defining layer 11 is further provided on the substrate 10, and the pixel defining layer 11 includes a plurality of openings, and one opening exposes one first electrode 50. Figure 6 The first sub-pixel 20 is taken as an example.

[0052] Here, if Figure 6 As shown, the substrate 10 includes a substrate substrate 12 and a plurality of driving circuits disposed on the substrate substrate 12, one driving circuit being electrically connected to a first electrode 50. The driving circuit includes a plurality of thin film transistors, and the drain of the thin film transistor serving as the driving transistor 14 among the plurality of thin film transistors is electrically connected to the first electrode 50.

[0053] On this basis, if Figure 6 As shown, the substrate 10 further includes a planar layer 13 disposed on a side of the driving circuit away from the base substrate 12 , and a surface of the first reflective layer 21 away from the second electrode 60 contacts a surface of the planar layer 13 away from the base substrate 12 .

[0054] Here, the materials of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 are not limited, and the materials of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 may be the same or different. In some embodiments, the materials of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 are pure metals or alloys. Exemplarily, the materials of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 may be silver, aluminum or silver-aluminum alloys thereof.

[0055] There is no limitation on the thickness of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41. The thickness of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 may be the same or different. In some embodiments, the thickness of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 ranges from 50 nm to 200 nm. Exemplarily, the thickness of the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 may be 200 nm, 100 nm and 50 nm, respectively.

[0056] In some embodiments, the first electrode 50 is a cathode and the second electrode 60 is an anode. In other embodiments, the first electrode 50 is an anode and the second electrode 60 is a cathode.

[0057] Here, the materials of the first electrode 50 and the second electrode 60 are not limited. In some embodiments, the materials of the first electrode 50 and the second electrode 60 may be metals, metal oxides or alloys. Exemplarily, the materials of the first electrode 50 and the second electrode 60 may be any one of indium tin oxide, indium zinc oxide, silver, aluminum, copper, molybdenum, etc.

[0058] In some embodiments, the display substrate further includes a light extraction layer 70 , which is disposed on a side of the second electrode 60 away from the first electrode 50 to reduce surface plasma loss and allow more light to be emitted from the light extraction layer 70 side.

[0059] Figure 6 In the example, the first electrode 50 is an anode and the second electrode 60 is a cathode. The display substrate also includes one or more layers of an electron transport layer 80 (election transporting layer, referred to as ETL), an electron injection layer 90 (election injection layer, referred to as EIL), a hole transport layer 100 (hole transporting layer, referred to as HTL) and a hole injection layer 110 (hole injection layer, referred to as HIL). Figure 6 As shown, when the first electrode 50 is an anode and the second electrode 60 is a cathode, the electron injection layer 90 and the electron transport layer 80 are arranged between the second electrode 60 and the light-emitting layer, and the hole injection layer 110 and the hole transport layer 100 are arranged between the first electrode 50 and the buffer layer. The buffer layer can play a role in hole blocking and can be called a hole blocking layer; at the same time, the buffer layer can also play a role in energy level matching.

[0060] When the first electrode 50 is a cathode and the second electrode 60 is an anode, the electron injection layer 90 and the electron transport layer 80 are arranged between the first electrode 50 and the buffer layer, and the hole injection layer 110 and the hole transport layer 100 are arranged between the second electrode 60 and the light-emitting layer. The buffer layer can play the role of electron blocking and can be called an electron blocking layer; at the same time, the buffer layer can also play the role of energy level matching. When the first electrode 50 is an anode and the second electrode 60 is a cathode, the first light-emitting pattern 24, the second light-emitting pattern 33 and the third light-emitting pattern 43 all belong to the light-emitting layer, and the first buffer pattern 23, the second buffer pattern 32 and the third buffer pattern 42 all belong to the buffer layer.

[0061] The embodiment of the present invention further provides a display device for displaying an image (i.e., a picture), which can be a product comprising the above-mentioned display substrate. For example, the display device can be a flat panel display (Flat Panel Display, FPD), a micro display, and other displays. If the scene is divided according to whether the user can see the back of the display, the display can be a transparent display or an opaque display. If the display can be bent or curled, the display can be a flexible display or a normal display (which can be called a rigid display). The display device can also be a product including a display, such as: a computer monitor, a television, a billboard, a laser printer with a display function, a telephone, a mobile phone, a personal digital assistant (Personal Digital Assistant, PDA), a laptop computer, a digital camera, a camcorder, a viewfinder, a vehicle, a large area wall, a theater screen or a stadium sign, etc.

[0062] Compared with the prior art, the beneficial effects of the display device provided by the embodiment of the present invention are the same as the beneficial effects of the display substrate provided by the above embodiment, which will not be elaborated here.

[0063] The embodiment of the present invention further provides a method for preparing a display substrate, which is used to prepare the above-mentioned display substrate, comprising:

[0064] Step S100, a plurality of sub-pixels are arranged on a substrate. The plurality of sub-pixels include: a first sub-pixel, a second sub-pixel, and a third sub-pixel with different luminous colors, each sub-pixel includes a transparent first electrode and a second electrode located on a side of the first electrode away from the substrate; the first sub-pixel also includes: a first reflective layer located between the substrate and the first electrode, a first insulating layer located between the first reflective layer and the first electrode, a first buffer pattern and a first luminous pattern located between the first electrode and the second electrode; the second sub-pixel also includes: a second reflective layer located between the substrate and the first electrode, a second buffer pattern and a second luminous pattern located between the first electrode and the second electrode; the third sub-pixel also includes: a third reflective layer located between the substrate and the first electrode, a third buffer pattern and a third luminous pattern located between the first electrode and the second electrode.

[0065] like Figure 7 and Fig. 9 As shown, in some embodiments, the above step S100 specifically includes:

[0066] Step S110: forming the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 on the substrate 10. Specifically, the metal reflective film can be formed by sputtering, and then the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41 can be obtained by exposure, development and etching.

[0067] Step S111: forming an insulating film covering the first reflective layer 21, the second reflective layer 31 and the third reflective layer 41. Specifically, the insulating film may be formed by a coating process.

[0068] Step S112: forming a first electrode layer on the substrate formed with the insulating film, the first electrode layer including a plurality of first electrodes; wherein the portion of the insulating film between the first reflective layer 21 and one of the first electrodes is the first insulating layer 22, the portion of the insulating film between the second reflective layer 31 and one of the first electrodes is the second insulating layer 34, and the portion of the insulating film between the third reflective layer 41 and one of the first electrodes is the third insulating layer 44. Here, the surface of the insulating film away from the substrate is flat, so that the first electrode layer can be formed on the flat surface. In detail, the first electrode layer can be formed by a sputtering process.

[0069] Step S113: forming a first buffer pattern and a first light-emitting pattern belonging to the first sub-pixel, a second buffer pattern and a second light-emitting pattern belonging to the second sub-pixel, and a third buffer pattern and a third light-emitting pattern belonging to the third sub-pixel on the substrate formed with the first electrode layer. In detail, the first buffer pattern and the first light-emitting pattern are formed in one chamber using an evaporation process using an FMM, the second buffer pattern and the second light-emitting pattern are formed in one chamber using an evaporation process using an FMM, and the third buffer pattern and the third light-emitting pattern are formed in one chamber using an evaporation process using an FMM.

[0070] Step S114: forming a second electrode layer, wherein a portion of the second electrode layer corresponding to one sub-pixel is a second electrode. Specifically, the second electrode layer may be formed by a sputtering process.

[0071] like Figure 8 and Fig.10 As shown, in some other embodiments, the above step S100 specifically includes:

[0072] Step S120: forming a first reflective layer 21 belonging to the first sub-pixel on the substrate 10. Specifically, the first metal reflective film may be formed by a sputtering process, and then the first reflective layer may be obtained by exposure, development and etching.

[0073] Step S121: forming a first insulating film covering the first reflective layer 21. Specifically, the first insulating film may be formed by a coating process.

[0074] Step S122: forming a second reflective layer 31 belonging to the second sub-pixel on the first insulating film. Specifically, the second metal reflective film can be formed by a sputtering process, and then the second reflective layer 31 can be obtained by exposure, development and etching.

[0075] Step S123: forming a second insulating film covering the second reflective layer 31. Specifically, the second insulating film may be formed by a coating process.

[0076] Step S124: forming a third reflective layer 41 belonging to the third sub-pixel on the second insulating film. Specifically, the third metal reflective film can be formed by a sputtering process, and then the third reflective layer 41 can be obtained by exposure, development and etching.

[0077] Step S125: forming a third insulating film covering the third reflective layer 41. Specifically, the second insulating film may be formed by a coating process.

[0078] Step S126: forming a first electrode layer 21 on the substrate 10 formed with the first insulating film, the second insulating film and the third insulating film, wherein the first electrode layer includes a plurality of first electrodes; wherein the first insulating film, the second insulating film and the third insulating film are located between the first reflective layer 21 and a first electrode as the first insulating layer 22, the second insulating film and the third insulating film are located between the second reflective layer 31 and a first electrode as the second insulating layer 34, and the third insulating film is located between the third reflective layer 41 and a first electrode as the third insulating layer 44. Specifically, the first electrode may be formed by a sputtering process.

[0079] Step S127: forming a first buffer pattern and a first light-emitting pattern belonging to the first sub-pixel, a second buffer pattern and a second light-emitting pattern belonging to the second sub-pixel, and a third buffer pattern and a third light-emitting pattern belonging to the third sub-pixel on the substrate formed with the first electrode layer. In detail, the first buffer pattern and the first light-emitting pattern are formed in one chamber using an evaporation process using an FMM, the second buffer pattern and the second light-emitting pattern are formed in one chamber using an evaporation process using an FMM, and the third buffer pattern and the third light-emitting pattern are formed in one chamber using an evaporation process using an FMM.

[0080] Step S128: forming a second electrode layer, wherein a portion of the second electrode layer corresponding to one sub-pixel is a second electrode. Specifically, the second electrode layer may be formed by a sputtering process.

[0081] The method for preparing a display substrate provided in an embodiment of the present invention has the same features and technical effects as the display substrate of the above embodiment, and reference may be made to the above embodiment, which will not be described in detail here.

[0082] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A display substrate, characterized in that: include: substrate; A plurality of sub-pixels are arranged on the substrate, the plurality of sub-pixels include: a first sub-pixel, a second sub-pixel and a third sub-pixel with different luminous colors, each of the sub-pixels includes a transparent first electrode and a second electrode located on a side of the first electrode away from the substrate; The first sub-pixel further includes: a first reflective layer between the substrate and the first electrode, a first insulating layer between the first reflective layer and the first electrode, a first buffer pattern and a first light-emitting pattern between the first electrode and the second electrode; The second sub-pixel further includes: a second reflective layer located between the substrate and the first electrode, a second buffer pattern and a second light-emitting pattern located between the first electrode and the second electrode; and a second insulating layer located between the second reflective layer and the first electrode; The third sub-pixel further includes: a third reflective layer located between the substrate and the first electrode, a third buffer pattern and a third light-emitting pattern located between the first electrode and the second electrode; and a third insulating layer located between the third reflective layer and the first electrode. The first reflective layer, the second reflective layer and the third reflective layer are located in different layers; The first insulating layer, the second insulating layer and the third insulating layer have different thicknesses and are connected; a surface of the first insulating layer away from the substrate, a surface of the second insulating layer away from the substrate and a surface of the third insulating layer away from the substrate are flush.

2. The display substrate according to claim 1, wherein: The first insulating layer comprises: a first insulating sublayer, a second insulating sublayer and a third insulating sublayer which are sequentially stacked in a direction away from the substrate; The second insulating layer comprises: a fourth insulating sublayer and a fifth insulating sublayer which are sequentially stacked in a direction away from the substrate; The third insulating sublayer, the fifth insulating sublayer and the third insulating layer belong to the same layer, and the third insulating sublayer, the fifth insulating sublayer and the third insulating layer are connected; The second insulating sublayer and the fourth insulating sublayer belong to the same layer, and the second insulating sublayer and the fourth insulating sublayer are connected.

3. The display substrate according to claim 1 or 2, characterized in that: A surface of the first buffer pattern close to the first light-emitting pattern contacts a surface of the first light-emitting pattern close to the first buffer pattern, and projections of the two on the substrate completely overlap; A surface of the second buffer pattern close to the second light-emitting pattern contacts a surface of the second light-emitting pattern close to the second buffer pattern, and projections of the two on the substrate completely overlap; A surface of the third buffer pattern close to the third light-emitting pattern contacts a surface of the third light-emitting pattern close to the third buffer pattern, and projections of the two on the substrate completely overlap.

4. A method for preparing a display substrate, characterized in that: include: A plurality of sub-pixels are arranged on the substrate, the plurality of sub-pixels comprising: a first sub-pixel, a second sub-pixel and a third sub-pixel with different luminous colors, each sub-pixel comprising a transparent first electrode and a second electrode located on a side of the first electrode away from the substrate; The first sub-pixel further includes: a first reflective layer between the substrate and the first electrode, a first insulating layer between the first reflective layer and the first electrode, a first buffer pattern and a first light-emitting pattern between the first electrode and the second electrode; The second sub-pixel further includes: a second reflective layer located between the substrate and the first electrode, a second buffer pattern and a second light-emitting pattern located between the first electrode and the second electrode; and a second insulating layer located between the second reflective layer and the first electrode; The third sub-pixel further includes: a third reflective layer located between the substrate and the first electrode, a third buffer pattern and a third light-emitting pattern located between the first electrode and the second electrode; and a third insulating layer located between the third reflective layer and the first electrode. The first reflective layer, the second reflective layer and the third reflective layer are located in different layers; the orthographic projections of the first reflective layer, the second reflective layer and the third reflective layer on the substrate completely overlap with the orthographic projection of the first electrode on the substrate; The first insulating layer, the second insulating layer and the third insulating layer have different thicknesses and are connected; a surface of the first insulating layer away from the substrate, a surface of the second insulating layer away from the substrate and a surface of the third insulating layer away from the substrate are flush.

5. The method for preparing a display substrate according to claim 4, characterized in that: The step of arranging a plurality of sub-pixels on a substrate comprises: forming a first reflective layer belonging to the first sub-pixel on the substrate; forming a first insulating film covering the first reflective layer; forming a second reflective layer belonging to the second sub-pixel on the first insulating film; forming a second insulating film covering the second reflective layer; forming a third reflective layer belonging to the third sub-pixel on the second insulating film; forming a third insulating film covering the third reflective layer; A first electrode layer is formed on the substrate on which the first insulating film, the second insulating film and the third insulating film are formed, wherein the first electrode layer includes a plurality of first electrodes; wherein a portion of the first insulating film, the second insulating film and the third insulating film located between the first reflective layer and one of the first electrodes is the first insulating layer, a portion of the second insulating film and the third insulating film located between the second reflective layer and one of the first electrodes is the second insulating layer, and a portion of the third insulating film located between the third reflective layer and one of the first electrodes is the third insulating layer; forming a first buffer pattern and a first light emitting pattern belonging to the first sub-pixel, a second buffer pattern and a second light emitting pattern belonging to the second sub-pixel, and a third buffer pattern and a third light emitting pattern belonging to the third sub-pixel on the substrate having the first electrode layer formed thereon; A second electrode layer is formed, wherein a portion of the second electrode layer corresponding to one sub-pixel is one second electrode.

6. A display device, characterized in that: A display substrate comprising the display substrate according to any one of claims 1 to 3.

Images