Light-emitting substrate and preparation method thereof
By forming an amorphous silicon layer and a light emitting functional layer on the auxiliary substrate, the problem of difficulty in growing an organic crystal thin film is solved, and high-quality thin film film formation is achieved, which facilitates the preparation of the light emitting substrate.
Patent Information
- Application Number
- CN202510173905.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-17
- Publication Date
- 2025-05-16
AI Technical Summary
When using weak orientation epitaxial growth technology to prepare organic crystal films, due to the change in the surface roughness of the amorphous substrate, it is difficult to grow small molecular crystal films.
By forming an amorphous silicon layer on the surface of the auxiliary substrate, and laying a light emitting functional layer and a second electrode layer on the surface, then removing the auxiliary substrate to form a first electrode layer, thereby completing the preparation of the crystalline OLED.
This method helps to reduce the difficulty of forming organic crystal films, improve the growth quality of the film, and facilitate the preparation of light emitting substrates.
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Figure CN120018739A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of display technology, and in particular, to a light-emitting substrate and a preparation method thereof. Background Art
[0002] Traditional amorphous organic light-emitting diodes have the advantages of self-luminescence, wide viewing angle, fast response, flexibility, high efficiency and energy saving. They are a new generation of full-color display and solid-state lighting technology and have been successfully applied in display fields such as smart phones and large-screen TVs.
[0003] Compared with traditional organic non-crystalline amorphous materials, organic crystalline materials have regular molecular arrangement, low impurity content, good stability and high carrier mobility. Therefore, crystalline organic light-emitting diodes based on organic crystalline materials have potential application value in improving the efficiency and stability of devices.
[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention
[0005] The present disclosure provides a light-emitting substrate and a preparation method thereof, which can reduce the difficulty of forming an organic crystalline thin film.
[0006] According to one aspect of the present disclosure, a method for preparing a light-emitting substrate is provided, wherein the light-emitting substrate comprises at least one crystalline OLED, wherein the crystalline OLED comprises a first electrode, a light-emitting functional unit, and a second electrode which are sequentially stacked;
[0007] The preparation method of the light-emitting substrate comprises:
[0008] Providing an auxiliary substrate, wherein a surface of the auxiliary substrate has an amorphous silicon layer;
[0009] Forming a light-emitting functional layer on the surface of the amorphous silicon layer, wherein the light-emitting functional layer includes the light-emitting functional units of each of the crystalline OLEDs;
[0010] Forming a second electrode layer on a side of the light-emitting functional layer away from the auxiliary substrate, wherein the second electrode layer has the second electrodes of each of the crystalline OLEDs;
[0011] removing the auxiliary substrate;
[0012] A first electrode layer is formed on a side of the light-emitting functional layer away from the second electrode layer, and the first electrode layer has the first electrodes of each of the crystalline OLEDs.
[0013] In one embodiment of the present disclosure, the amorphous silicon layer has a thickness of 5 to 500 nm and a hydrogen content of 2 wt % to 30 wt %;
[0014] The surface roughness of the amorphous silicon layer is less than 0.5 nm.
[0015] In one embodiment of the present disclosure, the amorphous silicon layer has a thickness of 5 to 15 nm and a hydrogen content of 5 wt % to 10 wt %.
[0016] In one embodiment of the present disclosure, the method for preparing the light-emitting substrate further includes:
[0017] After forming a second electrode layer on a side of the light-emitting functional layer away from the auxiliary substrate, a driving backplane layer is disposed on a side of the second electrode layer away from the light-emitting functional layer.
[0018] In one embodiment of the present disclosure, disposing a driving backplane layer on a side of the second electrode layer away from the light-emitting functional layer includes:
[0019] forming a connection layer on the surface of the second electrode layer, and arranging the driving backplane layer on a side of the connection layer away from the second electrode layer;
[0020] Wherein, the thickness of the connecting layer is greater than 0.2 μm.
[0021] In one embodiment of the present disclosure, the method for preparing the light-emitting substrate further includes:
[0022] After the first electrode layer is formed on a side of the light-emitting functional layer away from the second electrode layer, a thin film encapsulation layer is disposed on a side of the first electrode layer away from the light-emitting functional layer.
[0023] In one embodiment of the present disclosure, the method for preparing the light-emitting substrate further includes:
[0024] After forming a second electrode layer on a side of the light-emitting functional layer away from the auxiliary substrate, a thin film encapsulation layer is disposed on a side of the second electrode layer away from the light-emitting functional layer.
[0025] In one embodiment of the present disclosure, the method for preparing the light-emitting substrate further includes:
[0026] After forming the first electrode layer on the side of the light-emitting functional layer away from the second electrode layer, a driving backplane layer is disposed on the side of the first electrode layer away from the light-emitting functional layer.
[0027] In one embodiment of the present disclosure, disposing a driving backplane layer on a side of the first electrode layer away from the light-emitting functional layer includes:
[0028] A connection layer is formed on a side of the first electrode layer away from the light-emitting functional layer, and the driving backplane layer is arranged on a side of the connection layer away from the first electrode layer.
[0029] Wherein, the thickness of the connecting layer is greater than 0.2 μm.
[0030] According to a second aspect of the present disclosure, a light-emitting substrate is further provided, wherein the light-emitting substrate is prepared by the method for preparing a light-emitting substrate described in any of the above embodiments.
[0031] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.
[0033] Figure 1 FIG. 4 is a schematic diagram of film layers of a crystalline OLED in one embodiment of the present disclosure.
[0034] Figure 2 A schematic diagram of providing an auxiliary substrate in one embodiment of the present disclosure is provided.
[0035] Figure 3 FIG. 1 is a schematic diagram of forming a conductive layer on an amorphous silicon layer in one embodiment of the present disclosure.
[0036] Figure 4 It is a schematic diagram of forming an induction layer, an epitaxial layer, and a light-emitting functional layer on the surface of a conductive layer in one embodiment of the present disclosure.
[0037] Figure 5 It is a schematic diagram of forming an electron transport layer, a second electrode layer, and a connecting layer on the surface of the light-emitting functional layer in one embodiment of the present disclosure.
[0038] Figure 6 Schematic diagram of bonding a driving backplane layer to the surface of a connecting layer in one embodiment of the present disclosure.
[0039] Figure 7 FIG. 1 is a schematic diagram of removing the auxiliary substrate and the amorphous silicon layer in one embodiment of the present disclosure.
[0040] Figure 8 It is a schematic diagram of forming a first electrode layer on a side of the conductive layer away from the inductive layer in one embodiment of the present disclosure.
[0041] Fig. 9 It is a schematic diagram of forming a thin film encapsulation layer on a side of the first electrode layer away from the induction layer in one embodiment of the present disclosure.
[0042] Fig.10 It is a schematic diagram of forming an electron transport layer and a second electrode layer on the surface of the light-emitting functional layer in one embodiment of the present disclosure.
[0043] Fig.11 FIG. 1 is a schematic diagram of forming a thin film encapsulation layer on the surface of the second electrode layer in one embodiment of the present disclosure.
[0044] Fig.12 FIG. 1 is a schematic diagram of removing the auxiliary substrate and the amorphous silicon layer in one embodiment of the present disclosure.
[0045] Fig.13 It is a schematic diagram of forming a first electrode layer and a connecting layer on a side of the conductive layer away from the inductive layer in one embodiment of the present disclosure.
[0046] Fig.14 Schematic diagram of bonding the driving backplane layer to a side of the connecting layer away from the first electrode layer in one embodiment of the present disclosure.
[0047] Fig.15 This is a real picture of the growth of a small molecule organic crystalline thin film prepared by the preparation method disclosed in the present invention.
[0048] Fig.16 This is a real picture of the growth of small molecule organic crystalline film in the related technology. DETAILED DESCRIPTION
[0049] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.
[0050] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.
[0051] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.
[0052] The structure layer A is located on the side of the structure layer B away from the auxiliary substrate, which can be understood as the structure layer A being formed on the side of the structure layer B away from the auxiliary substrate. When the structure layer B is a patterned structure, part of the structure layer A may also be located at the same physical height as the structure layer B or lower than the physical height of the structure layer B, wherein the auxiliary substrate is a height reference.
[0053] In the related art, when preparing high-quality organic semiconductor crystalline films, weakly oriented epitaxial growth (WEG) technology is used. When using WEG technology to prepare organic crystalline films, firstly, an organic small molecule crystalline film that can grow in layers is introduced on an amorphous substrate as an induction layer, and then organic semiconductor molecules are continued to grow on the induction layer by vacuum deposition to prepare a large-size, continuous, high-quality and molecular-level rough crystalline film, also known as an epitaxial layer (Eputaxy layer).
[0054] In the above process, the main factors affecting the growth of organic crystalline thin films are evaporation rate, temperature of amorphous substrate and surface roughness of amorphous substrate. However, when using WEG technology to prepare organic crystalline thin films, due to the change of surface roughness of amorphous substrate, it is not conducive to the growth of small molecule crystalline thin films, and crystalline thin films are more difficult to form.
[0055] In order to solve the above problems, an embodiment of the present disclosure provides a method for preparing a light-emitting substrate.
[0056] See also Figure 1The light-emitting substrate includes at least one crystalline OLED, and the crystalline OLED includes a first electrode PEA, a light-emitting functional unit EFU, and a second electrode PEB stacked in sequence. One of the first electrode PEA and the second electrode PEB is a cathode, and the other is an anode.
[0057] The preparation method of the light-emitting substrate comprises the following steps:
[0058] Step S100, see Figure 2 , providing an auxiliary substrate AUB, wherein the surface of the auxiliary substrate AUB has an amorphous silicon layer ASL;
[0059] Step S200, see Figure 5 , Fig.10 , forming a light-emitting functional layer EFL on the surface of the amorphous silicon layer ASL, wherein the light-emitting functional layer EFL includes light-emitting functional units EFU of each crystalline OLED;
[0060] Step S300, see Figure 5 , Fig.10 , forming a second electrode layer PEBL on a side of the light emitting functional layer EFL away from the auxiliary substrate AUB, wherein the second electrode layer PEBL has second electrodes PEB of each crystalline OLED;
[0061] Step S400, see Figure 7 , Fig.12 , removing the auxiliary substrate AUB;
[0062] Step S500, see Figure 8 , Fig.13 A first electrode layer PEAL is formed on a side of the light emitting functional layer EFL away from the second electrode layer PEBL, and the first electrode layer PEAL has first electrodes PEA of each crystalline OLED.
[0063] Thus, in the embodiment of the present disclosure, an amorphous silicon layer ASL may be firstly provided on the surface of the auxiliary substrate AUB so that the auxiliary substrate AUB has a smaller surface roughness, and then a light-emitting functional layer EFL and a second electrode layer PEBL stacked in sequence are formed on the surface of the amorphous silicon layer ASL, and then the auxiliary substrate AUB is removed to form the first electrode layer PEAL, thereby completing the preparation of the crystalline OLED. Forming the light-emitting functional layer EFL on the surface of the amorphous silicon layer ASL is conducive to the growth of small molecule organic crystalline thin films in the crystalline OLED, reduces the difficulty of forming the organic crystalline thin films, and facilitates the preparation of the light-emitting substrate.
[0064] In one embodiment of the present disclosure, the light-emitting substrate may be a display panel or a lighting substrate to display images or provide lighting.
[0065] In one embodiment of the present disclosure, see Fig. 9 The light-emitting substrate to be prepared may include a thin film encapsulation layer TFE, a first electrode layer PEAL, a light-emitting functional layer EFL, a second electrode layer PEBL, and a driving backplane layer BPL stacked in sequence to form a bottom-emitting light-emitting substrate. In other embodiments of the present disclosure, see Fig.14 The light-emitting substrate to be prepared may include a driving backplane layer BPL, a first electrode layer PEAL, a light-emitting functional layer EFL, a second electrode layer PEBL, and a thin film encapsulation layer TFE which are stacked in sequence to form a top-emitting light-emitting substrate.
[0066] In one embodiment of the present disclosure, see Figure 1 The light-emitting functional unit EFU may include a conductive layer COL, an induction layer INL, an epitaxial layer EPL, an organic light-emitting layer EML, and an electron transport layer ETL which are stacked in sequence, a first electrode PEA is disposed on a side of the conductive layer COL away from the induction layer INL, and a second electrode PEB is disposed on a side of the electron transport layer ETL away from the organic light-emitting layer EML. In this way, the light-emitting function of the light-emitting functional unit EFU is realized.
[0067] In one embodiment of the present disclosure, the conductive layer COL is made of a transparent conductive material (eg, PEDOT:PSS) to improve conductivity.
[0068] In one embodiment of the present disclosure, in step S100, the thickness of the amorphous silicon layer ASL is 5 to 500 nm, for example, the thickness of the amorphous silicon layer ASL can be 5 nm, 55 nm, 105 nm, 155 nm, 205 nm, 255 nm, 305 nm, 355 nm, 405 nm, 455 nm or 500 nm, so as to prevent the amorphous silicon layer ASL from being too thick and difficult to dissociate. The hydrogen content (mass of hydrogen) of the amorphous silicon layer ASL is 2 wt% to 30 wt%, for example, the hydrogen content of the amorphous silicon layer ASL can be 2 wt%, 7 wt%, 12 wt%, 17 wt%, 22 wt%, 27 wt% or 30 wt%; on the one hand, it can prevent the dissociation effect of the amorphous silicon layer ASL from being affected by too little hydrogen content, and on the other hand, it can prevent the hydrogen from being too high to cause hydrogen to penetrate into the organic light-emitting layer EML, thereby reducing the influence on the light emission of the organic light-emitting layer EML. The surface roughness of the amorphous silicon layer ASL is less than 0.5 nm. For example, the surface roughness of the amorphous silicon layer ASL may be 0.1 nm, 0.2 nm, 0.3 nm, or 0.4 nm, which is conducive to the growth of small molecule organic crystalline thin films, thereby reducing the difficulty of forming organic crystalline thin films.
[0069] Optionally, in step S100, the auxiliary substrate AUB may be an auxiliary substrate AUB of an inorganic material, or an auxiliary substrate AUB of an organic material; of course, it may also be a composite substrate formed by stacking an auxiliary substrate AUB of an inorganic material and an auxiliary substrate AUB of an organic material. For example, in some embodiments of the present disclosure, the material of the auxiliary substrate AUB may be a glass material such as soda-lime glass, quartz glass, or sapphire glass.
[0070] In some other embodiments of the present disclosure, the material of the auxiliary substrate AUB can be polymethyl methacrylate, polyvinyl alcohol, polyvinyl phenol, polyether sulfone, polyimide, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polyethylene naphthalate or a combination thereof. In some other embodiments of the present disclosure, the auxiliary substrate AUB can also be a flexible auxiliary substrate, for example, the material of the auxiliary substrate AUB can include polyimide.
[0071] In one embodiment of the present disclosure, in step S100, the thickness of the amorphous silicon layer ASL is 5 to 15 nm, for example, the thickness of the amorphous silicon layer ASL can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm or 15 nm, so as to prevent the amorphous silicon layer ASL from being too thick and difficult to dissociate, thereby reducing costs. The hydrogen content of the amorphous silicon layer ASL is 5 wt% to 10 wt%, for example, the hydrogen content of the amorphous silicon layer ASL can be 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt% or 10 wt%; on the one hand, it can prevent the dissociation effect of the amorphous silicon layer ASL from being affected by too little hydrogen content, and on the other hand, it can prevent the hydrogen from being too high to cause hydrogen to penetrate into the organic light-emitting layer EML, thereby reducing the influence on the light emission of the organic light-emitting layer EML.
[0072] In one embodiment of the present disclosure, in step S200, forming a light emitting functional layer EFL on the surface of the amorphous silicon layer ASL includes:
[0073] Step S210, see Figure 3 , spin coating PEDOT:PSS material on the surface of the amorphous silicon layer ASL to form a conductive layer COL;
[0074] Step S220, see Figure 4 , forming an induction layer INL, an epitaxial layer EPL, and an organic light-emitting layer EML stacked in sequence on the surface of the conductive layer COL;
[0075] Step S230, see Figure 5 , an electron transport layer ETL is formed on a side of the organic light emitting layer EML away from the epitaxial layer EPL.
[0076] In one embodiment of the present disclosure, before step S210 , a pixel definition layer may be formed on the surface of the amorphous silicon layer ASL to facilitate the subsequent formation of pixel openings.
[0077] In one embodiment of the present disclosure, in step S220, an induction layer INL, an epitaxial layer EPL, and an organic light-emitting layer EML are sequentially stacked on the surface of the conductive layer COL by evaporation. The temperature during evaporation is 80°C to 110°C. For example, the temperature during evaporation can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, or 110°C to improve the preparation quality of the film layer.
[0078] In one embodiment of the present disclosure, in step S230, an electron transport layer ETL is formed on a side of the organic light emitting layer EML away from the epitaxial layer EPL by evaporation. The temperature during evaporation can be 20° C. to 25° C. For example, the temperature during evaporation can be 20° C., 21° C., 22° C., 23° C., 24° C., or 25° C. to facilitate the preparation of the electron transport layer ETL.
[0079] In one embodiment of the present disclosure, in step S300, the second electrode PEB can be a cathode, and the cathode can be evaporated using a metal material with high reflectivity. For example, the material of the cathode can be silver, aluminum or other metal materials to facilitate reflection of light so that the reflected optical fiber is emitted from the anode, which is beneficial to the preparation of a bottom-emitting light-emitting substrate.
[0080] In one embodiment of the present disclosure, in step S300, see Figure 6 After forming the second electrode layer PEBL on the side of the light-emitting functional layer EFL away from the auxiliary substrate AUB, a driving backplane layer BPL is disposed on the side of the second electrode layer PEBL away from the light-emitting functional layer EFL. In this way, the driving backplane layer BPL can drive the light-emitting functional layer EFL to emit light, and can also provide support for the light-emitting functional layer EFL, which is conducive to the removal of the auxiliary substrate AUB.
[0081] In one example, in step S300, disposing a driving backplane layer BPL on a side of the second electrode layer PEBL away from the light emitting functional layer EFL includes:
[0082] Step S310, see Figure 6 , forming a connection layer LIL on the surface of the second electrode layer PEBL;
[0083] Step S320 , disposing a driving backplane layer BPL on a side of the connection layer LIL away from the second electrode layer PEBL by bonding.
[0084] Among them, in step S310, the material of the connecting layer LIL is a metal material, for example, the material of the connecting layer LIL can be a metal material such as indium, tin, etc.; the material of the connecting layer LIL can also be a metal oxide material or a conductive adhesive material, for example, it can be anisotropic conductive adhesive (Anisotropic Conductive Film, ACF) or silver adhesive and other materials, because of its low melting point, it is easy to bond with the driving backplane layer BPL at a lower temperature.
[0085] Furthermore, the thickness of the connection layer LIL is greater than 0.2 μm. For example, the thickness of the connection layer LIL may be 0.21 μm, 0.26 μm, 0.31 μm, 0.36 μm or 0.4 μm, so as to prevent the bonding effect of the driving backplane layer BPL from being affected due to the small thickness of the connection layer LIL.
[0086] In step S320, the driving backplane layer BPL is a prefabricated product.
[0087] In another example, in step S300, disposing a driving backplane layer BPL on a side of the second electrode layer PEBL away from the light emitting functional layer EFL includes:
[0088] The driving backplane layer BPL is formed on the side of the second electrode layer PEBL away from the light-emitting functional layer EFL, that is, the connecting layer LIL is not provided, and the film layers of the driving backplane layer BPL are directly formed on the surface of the second electrode layer PEBL by evaporation, deposition, etc. using a film layer process.
[0089] In one embodiment of the present disclosure, in step S400, removing the auxiliary substrate AUB includes:
[0090] The amorphous silicon layer ASL is irradiated from one side of the auxiliary substrate AUB by an Excimer Laser Annealing (ELA) process.
[0091] The laser is an ultraviolet laser. After the ultraviolet laser irradiates the amorphous silicon layer ASL, since the amorphous silicon layer ASL contains hydrogen, the amorphous silicon layer ASL decomposes to produce hydrogen and polysilicon, so as to realize automatic dissociation of the auxiliary substrate AUB and facilitate automatic removal of the auxiliary substrate AUB.
[0092] In one embodiment of the present disclosure, in step S400, after removing the auxiliary substrate AUB, the silicon remaining on the side of the light-emitting functional layer EFL away from the second electrode layer PEBL is cleaned. In this way, the silicon on the side of the light-emitting functional layer EFL away from the second electrode layer PEBL is cleaned to improve the conductivity.
[0093] In one embodiment of the present disclosure, in step S500, the first electrode layer PEAL may be an anode, and the material of the anode may be a transparent conductive material, such as indium tin oxide (ITO), so that the anode has high transparency and good conductivity, which is beneficial to the preparation of a bottom-emitting light-emitting substrate.
[0094] In one embodiment of the present disclosure, the method for preparing the light-emitting substrate further includes:
[0095] Step S600, see Fig. 9 , a thin film encapsulation layer TFE is arranged on the side of the first electrode layer PEAL away from the light-emitting functional layer EFL. The thin film encapsulation layer TFE may include an inorganic encapsulation layer and an organic encapsulation layer alternately stacked. The inorganic encapsulation layer can effectively block external moisture and oxygen, and prevent water and oxygen from invading the light-emitting functional layer EFL and causing aging of the material in the light-emitting functional layer EFL. Optionally, the edge of the inorganic encapsulation layer may be located in the peripheral area. The organic encapsulation layer is located between two adjacent inorganic encapsulation layers to achieve planarization and reduce the stress between the inorganic encapsulation layers. Among them, the edge of the organic encapsulation layer may be located between the edge of the display area and the edge of the inorganic encapsulation layer.
[0096] Exemplarily, the thin film encapsulation layer TFE includes a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer (not specifically shown in this figure) stacked in sequence on the side of the light-emitting functional layer EFL away from the driving backplane layer BPL. The first inorganic encapsulation layer covers the display area and extends to the outside of the baffle wall; the organic encapsulation layer covers the display area and extends to the inside of the baffle wall; the second inorganic encapsulation layer covers the organic encapsulation layer and extends to the outside of the baffle wall. On the outside of the baffle wall, the second inorganic encapsulation layer contacts the first inorganic encapsulation layer. In this way, the organic encapsulation layer is enclosed by the first inorganic encapsulation layer and the second inorganic encapsulation layer, and the stress of the first inorganic encapsulation layer and the second inorganic encapsulation layer is balanced. The first inorganic encapsulation layer and the second inorganic encapsulation layer encapsulate the organic encapsulation layer to isolate the organic encapsulation layer from contact with water and oxygen. Of course, in other embodiments of the present disclosure, the light-emitting substrate may not be provided with a thin film encapsulation layer TFE, but may be encapsulated and protected by other methods for the light-emitting functional layer EFL.
[0097] In one embodiment of the present disclosure, in step S300, see Fig.11 After forming the second electrode layer PEBL on the side of the light-emitting functional layer EFL away from the auxiliary substrate AUB, a thin film encapsulation layer TFE is disposed on the side of the second electrode layer PEBL away from the light-emitting functional layer EFL to support and encapsulate the light-emitting functional layer EFL. In an example, the thin film encapsulation layer TFE may include an encapsulation layer and a cover layer, the encapsulation layer encapsulates the light-emitting functional layer EFL, and the cover layer provides support for the light-emitting functional layer EFL to facilitate the dissociation of the auxiliary substrate AUB.
[0098] In one embodiment of the present disclosure, in step S500, after forming the first electrode layer PEAL on the side of the light-emitting functional layer EFL away from the second electrode layer PEBL, a driving backplane layer BPL is disposed on the side of the first electrode layer PEAL away from the light-emitting functional layer EFL. In this way, the driving backplane layer BPL can drive the light-emitting functional layer EFL to emit light.
[0099] In one example, in step S500, disposing a driving backplane layer BPL on a side of the first electrode layer PEAL away from the light emitting functional layer EFL includes:
[0100] Step S510, see Fig.13 , forming a connection layer LIL on a side of the first electrode layer PEAL away from the light emitting functional layer EFL;
[0101] Step S520, see Fig.14 A driving backplane layer BPL is arranged on a side of the connection layer LIL away from the second electrode layer PEBL by bonding.
[0102] In which, in step S510, the material of the connecting layer LIL is a metal material, for example, the material of the connecting layer LIL can be a metal material such as indium, tin, etc.; the material of the connecting layer LIL can also be a metal oxide material or a conductive adhesive material, for example, it can be anisotropic conductive adhesive (Anisotropic Conductive Film, ACF) or silver adhesive and other materials, because of its low melting point, it is convenient to bond with the driving backplane layer BPL at a lower temperature.
[0103] Furthermore, the thickness of the connection layer LIL is greater than 0.2 μm. For example, the thickness of the connection layer LIL can be 0.21 μm, 0.26 μm, 0.31 μm, 0.36 μm or 0.4 μm to prevent the bonding effect of the driving backplane layer BPL from being affected due to the thickness of the connection layer LIL being too small.
[0104] In step S520, the driving backplane layer BPL is a prefabricated product.
[0105] In another example, in step S500, disposing a driving backplane layer BPL on a side of the first electrode layer PEAL away from the light emitting functional layer EFL includes:
[0106] A driving backplane layer BPL is formed on the side of the first electrode layer PEAL away from the light-emitting functional layer EFL, that is, no connecting layer LIL is set, and the various film layers of the driving backplane layer BPL are directly formed by evaporation, deposition, etc. on the side of the first electrode layer PEAL away from the light-emitting functional layer EFL using a film layer process.
[0107] In step S520, the first electrode layer PEAL can be an anode, and the material of the anode can be a high-reflectivity conductive material. For example, the anode can include three conductive metal layers stacked in sequence, the material of the middle conductive metal layer is silver, and the materials of the other two conductive metal layers can be indium tin oxide, so that the anode has high reflectivity and good conductivity, which is conducive to the preparation of top-emitting light-emitting substrates.
[0108] See also Fig.15 and Fig.16 , when the evaporation rate and the temperature of the amorphous substrate are constant, the growth of small molecule organic crystalline thin films on amorphous substrates with different surface roughness is different. Specifically, the growth morphology on the auxiliary substrate with an amorphous silicon layer is good, and the growth morphology on the indium tin oxide (ITO) substrate is poor and difficult to form a film. Among them, the surface roughness of the amorphous silicon layer is less than 0.5nm, and the surface roughness of the indium tin oxide substrate is greater than 0.8nm. It can be seen that the preparation method of the light-emitting substrate provided in the embodiment of the present disclosure is conducive to the growth of small molecule organic crystalline thin films and facilitates the preparation of organic crystalline thin films.
[0109] In one embodiment of the present disclosure, the light-emitting substrate prepared by the above-mentioned method for preparing a light-emitting substrate may be a bottom-emitting light-emitting substrate or a top-emitting light-emitting substrate. Fig. 9 The bottom emission type light-emitting substrate may include a thin film encapsulation layer TFE, a first electrode layer PEAL, a conductive layer COL, an induction layer INL, an epitaxial layer EPL, an organic light-emitting layer EML, an electron transport layer ETL, a second electrode layer PEBL, a connecting layer LIL, and a driving backplane layer BPL which are stacked in sequence.
[0110] See also Fig.14 The top emission type light-emitting substrate may include a driving backplane layer BPL, a connecting layer LIL, a first electrode layer PEAL, a conductive layer COL, an induction layer INL, an epitaxial layer EPL, an organic light-emitting layer EML, an electron transport layer ETL, a second electrode layer PEBL, and a thin film encapsulation layer TFE which are stacked in sequence.
[0111] It should be noted that, although the steps of the method for preparing the light-emitting substrate in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.
[0112] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.
Claims
1. A method for preparing a light-emitting substrate, characterized in that: The light-emitting substrate includes at least one crystalline OLED, and the crystalline OLED includes a first electrode, a light-emitting functional unit, and a second electrode which are sequentially stacked; The preparation method of the light-emitting substrate comprises: Providing an auxiliary substrate, wherein a surface of the auxiliary substrate has an amorphous silicon layer; Forming a light-emitting functional layer on the surface of the amorphous silicon layer, wherein the light-emitting functional layer includes the light-emitting functional units of each of the crystalline OLEDs; Forming a second electrode layer on a side of the light-emitting functional layer away from the auxiliary substrate, wherein the second electrode layer has the second electrodes of each of the crystalline OLEDs; removing the auxiliary substrate; A first electrode layer is formed on a side of the light-emitting functional layer away from the second electrode layer, and the first electrode layer has the first electrodes of each of the crystalline OLEDs.
2. The method for preparing a light-emitting substrate according to claim 1, characterized in that: The amorphous silicon layer has a thickness of 5 to 500 nm and a hydrogen content of 2 wt% to 30 wt%; The surface roughness of the amorphous silicon layer is less than 0.5 nm.
3. The method for preparing a light-emitting substrate according to claim 2, characterized in that: The amorphous silicon layer has a thickness of 5 to 15 nm and a hydrogen content of 5 wt % to 10 wt %.
4. The method for preparing a light-emitting substrate according to claim 1, characterized in that: The method for preparing the light-emitting substrate further includes: After forming a second electrode layer on a side of the light-emitting functional layer away from the auxiliary substrate, a driving backplane layer is disposed on a side of the second electrode layer away from the light-emitting functional layer.
5. The method for preparing a light-emitting substrate according to claim 4, characterized in that: Providing a driving backplane layer on a side of the second electrode layer away from the light-emitting functional layer comprises: forming a connection layer on the surface of the second electrode layer, and arranging the driving backplane layer on a side of the connection layer away from the second electrode layer; Wherein, the thickness of the connecting layer is greater than 0.2 μm.
6. The method for preparing a light-emitting substrate according to claim 5, characterized in that: The method for preparing the light-emitting substrate further includes: After the first electrode layer is formed on a side of the light-emitting functional layer away from the second electrode layer, a thin-film encapsulation layer is disposed on a side of the first electrode layer away from the light-emitting functional layer.
7. The method for preparing a light-emitting substrate according to claim 1, characterized in that: The method for preparing the light-emitting substrate further includes: After forming a second electrode layer on a side of the light-emitting functional layer away from the auxiliary substrate, a thin film encapsulation layer is disposed on a side of the second electrode layer away from the light-emitting functional layer.
8. The method for preparing a light-emitting substrate according to claim 7, characterized in that: The method for preparing the light-emitting substrate further includes: After forming the first electrode layer on the side of the light-emitting functional layer away from the second electrode layer, a driving backplane layer is disposed on the side of the first electrode layer away from the light-emitting functional layer.
9. The method for preparing a light-emitting substrate according to claim 8, characterized in that: Providing a driving backplane layer on a side of the first electrode layer away from the light-emitting functional layer comprises: Forming a connection layer on a side of the first electrode layer away from the light-emitting functional layer, and arranging the driving backplane layer on a side of the connection layer away from the first electrode layer; Wherein, the thickness of the connecting layer is greater than 0.2 μm.
10. A light-emitting substrate, characterized in that: The light-emitting substrate is prepared by the method for preparing a light-emitting substrate according to any one of claims 1 to 9.
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CN120916577A