Silicon-based organic electroluminescent microdisplay and preparation method thereof

Abstract

The embodiment of the present invention discloses a silicon-based organic electroluminescent microdisplay and a preparation method thereof. The silicon-based organic electroluminescent microdisplay comprises: a silicon-based circuit substrate, the silicon-based circuit substrate comprises a silicon-based substrate and a driving circuit located on the silicon-based substrate; a plurality of sub-pixels, the sub-pixels are arranged on the silicon-based circuit substrate, the sub-pixels comprise a first electrode, a buffer pattern, an organic light-emitting layer and a second electrode stacked in sequence, the first electrode being electrically connected to the driving circuit; wherein the buffer pattern is formed by patterning a buffer layer, and the buffer layer is prepared using an aqueous solution of a buffer material. The embodiment of the present invention solves the problem of lateral leakage between sub-pixels in the existing silicon-based organic electroluminescent microdisplay, can avoid cross-coloring between sub-pixels, and can improve the hole injection capacity of the sub-pixels, improve the recombination efficiency of carriers, and enhance the luminous efficiency of the sub-pixels.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of display technology, and in particular to a silicon-based organic electroluminescent microdisplay and a preparation method thereof. Background Art

[0002] Silicon-based organic electroluminescent devices are optoelectronic devices that further produce organic electroluminescent materials on a single-crystal silicon substrate with semiconductor CMOS circuits. After packaging, they can form silicon-based organic light-emitting microdisplays. Silicon-based organic electroluminescent displays have the characteristics of brightness, rich colors, low driving voltage, fast response speed and low power consumption, and can provide higher resolution in a display area of ​​less than 1 inch. Therefore, they are developing very rapidly and can be used in the fields of military, medicine, industry, aerospace, and entertainment consumer electronics, especially in novel applications such as wearable devices, virtual displays, and augmented reality.

[0003] At present, the common process route of silicon-based organic electroluminescent microdisplay is to prepare the CMOS bottom circuit in the wafer factory, and then make the subsequent evaporation packaging, CF, cutting, bonding and other processes in the panel display factory. The wafer factory will prepare the anode while preparing the bottom circuit, or the anode can also be prepared in the panel factory, resulting in the anode of the silicon-based organic electroluminescent microdisplay usually being made of metal or metal nitride such as aluminum or aluminum nitride. In the sub-pixel, the anode made of Al or TiN has a lower work function, resulting in a decrease in the hole injection ability. In order to solve this problem, p-doped organic materials such as NPD-9 are currently used to improve the injection ability of the anode when preparing silicon-based sub-pixels. However, since the current preparation method of silicon-based organic electroluminescent microdisplays uses an open mask to evaporate a layer of the p-doped organic material, and since the NPD-9 material is extremely conductive, the spacing between sub-pixels is very small (generally around 1um), which easily leads to lateral leakage between sub-pixels, and then cross-color occurs between adjacent sub-pixels, resulting in a decrease in color gamut. Summary of the invention

[0004] The present invention provides a silicon-based organic electroluminescent microdisplay and a preparation method thereof, so as to improve the preparation process of the silicon-based organic electroluminescent microdisplay, enhance the mutual insulation ability of the silicon-based organic electroluminescent microdisplay, and avoid the cross-color problem between silicon-based organic electroluminescent microdisplays.

[0005] In a first aspect, an embodiment of the present invention provides a silicon-based organic electroluminescent microdisplay, comprising:

[0006] A silicon-based circuit substrate, the silicon-based circuit substrate comprising a silicon-based substrate and a driving circuit located on the silicon-based substrate;

[0007] A plurality of sub-pixels, wherein the sub-pixels are arranged on the silicon-based circuit substrate, and the sub-pixels include a first electrode, a buffer pattern, an organic light-emitting layer, and a second electrode which are sequentially stacked, and the first electrode is electrically connected to the driving circuit;

[0008] Wherein, the buffer pattern is formed by patterning a buffer layer, and the buffer layer is prepared by using an aqueous solution of a buffer material.

[0009] Optionally, it further comprises an encapsulation layer, a color filter layer and a cover glass which are stacked in sequence, wherein the color filter layer comprises a plurality of color filter dots;

[0010] The encapsulation layer is located on a side of the plurality of sub-pixels away from the silicon-based circuit substrate and covers the plurality of sub-pixels;

[0011] The color filter layer is located on a side of the encapsulation layer away from the sub-pixels, and the plurality of color filter dots correspond one-to-one to the plurality of sub-pixels;

[0012] The cover glass is located on a side of the color filter layer away from the encapsulation layer.

[0013] In a second aspect, an embodiment of the present invention further provides a method for preparing a silicon-based organic electroluminescent microdisplay, comprising:

[0014] Using an aqueous solution of a buffer material, a buffer layer is formed on a plurality of first electrodes on a silicon-based circuit substrate, wherein the plurality of first electrodes are evenly arranged on the silicon-based circuit substrate;

[0015] Patterning the buffer layer to form a plurality of buffer patterns, wherein the buffer patterns correspond to the first electrodes and are stacked one on top of the other;

[0016] An organic light-emitting layer and a second electrode are sequentially formed on a side of each buffer pattern away from the first electrode to form a plurality of sub-pixels.

[0017] Optionally, the silicon-based circuit substrate comprises a silicon-based substrate and a driving circuit located on the silicon-based substrate, and the driving circuit comprises a plurality of the first electrodes;

[0018] A buffer layer is formed on a plurality of first electrodes on a silicon-based circuit substrate using an aqueous solution of a buffer material, comprising:

[0019] Forming a photoresist pattern on the silicon-based circuit substrate, wherein the photoresist in the photoresist pattern is located between any two adjacent first electrodes, and a surface of the first electrode facing away from the silicon-based substrate is flush with a surface of the photoresist pattern facing away from the silicon-based substrate;

[0020] coating an aqueous solution of a buffer material on the photoresist pattern and the plurality of first electrodes to form a buffer layer;

[0021] The buffer layer is patterned to form a plurality of buffer patterns, including:

[0022] An oil-soluble organic solvent is used to dissolve the photoresist pattern and to peel off the film layer on the photoresist pattern to form a plurality of buffer patterns.

[0023] Optionally, forming a photoresist pattern on the silicon-based circuit substrate comprises:

[0024] forming a photoresist layer on the silicon-based circuit substrate, wherein the photoresist layer covers the first electrode and the silicon-based substrate;

[0025] curing the photoresist layer;

[0026] The photoresist layer is exposed and developed to form the photoresist pattern.

[0027] Optionally, the silicon-based circuit substrate comprises a silicon-based substrate and a driving circuit located on the silicon-based substrate, and the driving circuit comprises a plurality of guiding electrodes;

[0028] A buffer layer is formed on a plurality of first electrodes on a silicon-based circuit substrate using an aqueous solution of a buffer material, comprising:

[0029] Forming a photoresist pattern on the silicon-based circuit substrate, wherein the photoresist in the photoresist pattern is located between any two adjacent guide electrodes;

[0030] forming a first electrode layer on the photoresist pattern and the guide electrode;

[0031] coating an aqueous solution of a buffer material on the first electrode layer to form a buffer layer;

[0032] The buffer layer is patterned to form a plurality of buffer patterns, including:

[0033] An oil-soluble organic solvent is used to dissolve the photoresist pattern and the film layer on the photoresist pattern to form a plurality of buffer patterns.

[0034] Optionally, forming a photoresist pattern on the silicon-based circuit substrate comprises:

[0035] forming a photoresist layer on the silicon-based circuit substrate, wherein the photoresist layer covers the guide electrode and the silicon-based substrate;

[0036] curing the photoresist layer;

[0037] The photoresist layer is exposed and developed to form the photoresist pattern.

[0038] Optionally, before using an oil-soluble organic solvent to dissolve the photoresist pattern and peel off the film layer on the photoresist pattern to form a plurality of the buffer patterns, the preparation method further comprises:

[0039] The buffer layer is annealed.

[0040] Optionally, the annealing temperature of the annealing treatment is 80-250° C., and the annealing time is 30 min-2 h.

[0041] Optionally, after an organic light-emitting layer and a second electrode are sequentially formed on a side of each buffer pattern away from the first electrode to form a plurality of sub-pixels, the method further includes:

[0042] On the side of the sub-pixel away from the silicon-based circuit substrate, a packaging layer, a color filter layer and a cover glass are formed in sequence.

[0043] The silicon-based organic electroluminescent microdisplay and its preparation method provided by the embodiment of the present invention form a buffer layer on multiple first electrodes on a silicon-based circuit substrate through an aqueous solution of a buffer material, and then pattern the buffer layer to form multiple buffer graphics, the buffer graphics and the first electrodes are stacked up and down in a one-to-one correspondence, and finally, on the side of each buffer graphic away from the first electrode, an organic light-emitting layer and a second electrode are sequentially formed to form multiple sub-pixels, thereby improving the surface work function of the first electrode, reducing the potential barrier between the first electrode and the organic layer, and ensuring the performance of the silicon-based organic electroluminescent microdisplay. The embodiment of the present invention solves the problem of lateral leakage between sub-pixels of the existing silicon-based organic electroluminescent microdisplay, can avoid cross-color between sub-pixels, and can improve the hole injection capacity of the sub-pixels, improve the recombination efficiency of carriers, and enhance the luminous efficiency of the sub-pixels. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention;

[0045] Figure 2 is a schematic structural diagram of another silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention;

[0046] Figure 3 It is a flow chart of a method for preparing a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention;

[0047] Figure 4 yes Figure 3 The structural flow chart of the method for preparing a silicon-based organic electroluminescent microdisplay is shown;

[0048] Figure 5It is a flow chart of another method for preparing a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention;

[0049] Figure 6 yes Figure 5 The structural flow chart of the method for preparing a silicon-based organic electroluminescent microdisplay is shown;

[0050] Figure 7 It is a flow chart of another method for preparing a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention;

[0051] Figure 8 yes Figure 7 The structural flow chart of the method for preparing a silicon-based organic electroluminescent microdisplay is shown. DETAILED DESCRIPTION

[0052] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0053] Figure 1 is a schematic diagram of the structure of a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention, with reference to Figure 1 The silicon-based organic electroluminescent micro display comprises a silicon-based circuit substrate 10, the silicon-based circuit substrate 10 comprises a silicon-based substrate 12 and a driving circuit 14 located on the silicon-based substrate 12; a plurality of sub-pixels 100, the sub-pixels 100 are arranged on the silicon-based circuit substrate 10, the sub-pixels 100 comprise a first electrode 11, a buffer pattern 21, an organic light-emitting layer 30 and a second electrode 40 which are stacked in sequence, and the first electrode 11 is electrically connected to the driving circuit 14. The buffer pattern 21 is formed by patterning a buffer layer, and the buffer layer is prepared by using an aqueous solution of a buffer material.

[0054] Among them, the silicon-based circuit substrate 10 is a silicon-based substrate after the CMOS underlying circuit is prepared on the wafer, and the CMOS underlying circuit on the silicon-based circuit substrate 10 is used to separately drive and control the sub-pixels prepared thereon. The first electrode 11 arranged on the silicon-based circuit substrate 10 is the anode or cathode in the sub-pixel. Here, it is an optimized sub-pixel device structure, and the first electrode can be selected as the anode. Each first electrode 11 on the silicon-based circuit substrate 10 is respectively prepared to form a sub-pixel, and the sub-pixel is essentially an OLED device. Therefore, in order to ensure the insulation of adjacent sub-pixels, multiple first electrodes 11 are insulated from each other. Specifically, the first electrode 11 can be arranged in an array according to the arrangement requirements of the sub-pixels, and there is no limitation here.

[0055] It is understandable that the first electrode 11 is usually made of metal or metal nitride in the existing preparation process, and its work function is generally low, which is not conducive to the hole injection of the sub-pixel, resulting in low carrier recombination efficiency and luminous efficiency of the sub-pixel. In the embodiment of the present invention, a buffer pattern 21 is added to the first electrode 11 of the sub-pixel 100. For the sub-pixel 100, it is actually a buffer layer structure, so that the buffer pattern 21 can be used to reduce the potential barrier, improve the hole injection efficiency, and improve the carrier recombination efficiency and luminous efficiency of the sub-pixel. On the silicon-based circuit substrate 10, a sub-pixel 100 is formed corresponding to each first electrode 11. By driving the driving circuit 14 on the silicon-based circuit substrate 10, the lighting and closing of each sub-pixel 100 can be controlled, so that the switch and brightness of the silicon-based organic electroluminescent microdisplay can be controlled to perform functions such as lighting and display.

[0056] In addition, it should be noted that the buffer pattern in the above-mentioned sub-pixel 100 is prepared by using an aqueous solution of a buffer material to form a buffer layer, and then the buffer layer is patterned to form a buffer pattern 21. The aqueous solution of the buffer material refers to dissolving the buffer material in water, using a coating method such as spin coating or spraying, and removing the water solvent to form a buffer layer, wherein the buffer material can be uniformly dissolved by stirring, oscillating, etc. The buffer layer refers to a relatively flat film layer composed of a buffer material, and its film thickness can be adjusted according to the concentration of the aqueous solution, the amount of liquid spin-coated or sprayed, and the process parameters during spin coating or spraying. The patterning process of the buffer layer is essentially a process of dividing the buffer layer to form a plurality of independent and insulated patterns. The division process is not achieved by physical methods such as cutting, but is generally achieved by chemical methods such as dissolution and etching. Compared with the existing method of using organic buffer materials to prepare a whole buffer layer through deposition processes such as thermal evaporation, the silicon-based organic electroluminescent microdisplay provided in this embodiment is prepared by coating with an aqueous solution and then patterning to form a buffer pattern, which can avoid the problem that the existing buffer layers made of open masks are mutually conductive and easily cause lateral leakage of adjacent sub-pixels.

[0057] The silicon-based organic electroluminescent microdisplay provided by the embodiment of the present invention is provided with a silicon-based circuit substrate, the silicon-based circuit substrate is provided with a silicon-based substrate and a driving circuit located on the silicon-based substrate, and a plurality of sub-pixels are provided, the sub-pixels are provided on the silicon-based circuit substrate, the sub-pixels include a first electrode, a buffer pattern, an organic light-emitting layer and a second electrode which are stacked in sequence, and the first electrode is electrically connected to the driving circuit; wherein the buffer pattern is formed by patterning the buffer layer, and the buffer layer is prepared by using an aqueous solution of a buffer material, which improves the surface work function of the first electrode, reduces the potential barrier between the first electrode and the organic layer, and ensures the performance of the silicon-based organic electroluminescent microdisplay. The embodiment of the present invention can solve the problem of lateral leakage between sub-pixels in the existing silicon-based organic electroluminescent microdisplay, can avoid mutual cross-color between sub-pixels, and can improve the hole injection ability of the sub-pixels, improve the recombination efficiency of carriers, and enhance the luminous efficiency of the sub-pixels.

[0058] Furthermore, the silicon-based organic electroluminescent microdisplay also includes an encapsulation layer 50, a color filter layer 60 and a cover glass 70 which are stacked in sequence, the color filter layer 60 includes a plurality of color filter dots 61; the encapsulation layer 50 is located on a side of the plurality of sub-pixels 100 away from the silicon-based circuit substrate 10, and covers the plurality of sub-pixels 100; the color filter layer 60 is located on a side of the encapsulation layer 50 away from the ionic pixels 100, and the plurality of color filter dots 61 correspond one-to-one to the plurality of sub-pixels 100; the cover glass 70 is located on a side of the color filter layer 60 away from the encapsulation layer 50.

[0059] Among them, the encapsulation layer 50 is made of pure inorganic materials, such as a laminated structure of SiO / SiN / Al2O3, or an inorganic / organic / inorganic laminated structure can also be used, and its specific materials are not limited. The encapsulation layer 50 is used to seal and protect each sub-pixel 100 to prevent it from being eroded by air and water vapor, thereby ensuring that the organic material in the sub-pixel 100 will not deteriorate and ensuring efficient luminous efficiency. The color filter layer 60 is a color filter point added to each sub-pixel 100, through which the color of the light emitted by the sub-pixel 100 can be converted. As shown in the figure, for example, three adjacent sub-pixels 100 can be respectively set with three color filter points of red, green and blue, so that a pixel unit is formed by sub-pixels 100 of red, green and blue colors, so as to match colors and present a full-color display screen.

[0060] Figure 2 is a schematic diagram of the structure of another silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention, with reference to Figure 2 It should be noted that if Figure 1 and Figure 2 The difference between the two silicon-based organic electroluminescent micro displays shown in the figure is whether the first electrode 11 is simultaneously prepared when the CMOS driving circuit 14 is prepared on the silicon-based circuit substrate 10. Figure 2In the silicon-based organic electroluminescent microdisplay shown, since the first electrode 11 is not provided on the silicon-based circuit substrate 10, in order to realize the electrical connection between the sub-pixel 100 and the driving circuit 14, it is necessary to provide a plurality of guide electrodes 13 on the silicon-based circuit substrate 10, and connect the driving circuit 14 to the first electrode 11 of the sub-pixel 100 through the guide electrodes 13, thereby realizing the control of the light emission of the sub-pixel 100.

[0061] The present invention also provides a method for preparing a silicon-based organic electroluminescent microdisplay. Figure 3 is a flow chart of a method for preparing a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention, Figure 4 yes Figure 3 The structural flow chart of the method for preparing a silicon-based organic electroluminescent microdisplay is shown in FIG. Figure 3 and Figure 4 The method for preparing the silicon-based organic electroluminescent microdisplay comprises:

[0062] S110, using an aqueous solution of a buffer material to form a buffer layer on a plurality of first electrodes on a silicon-based circuit substrate, wherein the plurality of first electrodes are evenly arranged on the silicon-based circuit substrate.

[0063] refer to Figure 4 a), wherein the silicon-based circuit substrate 10 is a silicon-based substrate after the CMOS underlying circuit is prepared on the wafer, and the CMOS underlying circuit on the silicon-based circuit substrate 10 is used to separately drive and control the sub-pixels prepared thereon. The first electrode 11 arranged on the silicon-based circuit substrate 10 is the anode or cathode in the sub-pixel, which is an optimized sub-pixel device structure, and the first electrode can be optionally the anode. Each first electrode 11 on the silicon-based circuit substrate 10 can be prepared to form a sub-pixel, so in order to ensure the insulation of adjacent sub-pixels, multiple first electrodes 11 are insulated from each other. Specifically, the first electrode 11 can be arranged in an array according to the arrangement requirements of the sub-pixels, and there is no limitation here.

[0064] It is understandable that in the existing preparation process, the first electrode 11 is usually made of metal or metal nitride, and its work function is generally low, which is not conducive to the hole injection of the sub-pixel, resulting in low carrier recombination efficiency and luminescence efficiency of the sub-pixel. By adding a buffer layer 20 to the first electrode 11 of the sub-pixel, the buffer layer 20 can be used to reduce the potential barrier, improve the hole injection efficiency, and improve the carrier recombination efficiency and luminescence efficiency of the sub-pixel. The aqueous solution of the buffer material refers to dissolving the buffer material in water, using a coating method such as spin coating or spraying, and removing the water solvent to form a buffer layer 20, wherein the buffer material can be uniformly dissolved by stirring, oscillating, etc. The buffer layer 20 refers to a relatively flat film layer composed of a buffer material, and its film thickness can be adjusted according to the concentration of the aqueous solution, the amount of liquid for spin coating or spraying, and the process parameters during spin coating or spraying.

[0065] S120, patterning the buffer layer to form a plurality of buffer patterns, wherein the buffer patterns correspond to the first electrodes and are stacked one on top of another.

[0066] refer to Figure 4 b), the buffer layer 20 formed in step S110 is a whole film structure, refer to Figure 4 As shown in FIG. b), this step is essentially to divide the buffer layer 20 to form a buffer pattern 21 for each sub-pixel. The patterning process of the buffer layer is essentially to divide the buffer layer into multiple independent and insulated patterns. The division process is not achieved by physical methods such as cutting, but is generally achieved by chemical methods such as dissolution and etching. Each buffer pattern 21 is arranged in the same manner as the first electrode 11, and is insulated from each other, presenting a stacked relationship.

[0067] It should be noted that, through step S110 and step S120, a buffer layer is prepared using an aqueous solution of a buffer material, and the buffer layer 20 is divided. Compared with the existing method of preparing organic buffer materials through deposition processes such as thermal evaporation, the silicon-based organic electroluminescent microdisplay preparation process provided in this embodiment can avoid the problem that the buffer layers made of the existing open mask are mutually conductive and easily cause lateral leakage of adjacent sub-pixels.

[0068] S130 , sequentially forming an organic light-emitting layer and a second electrode on a side of each buffer pattern away from the first electrode to form a plurality of sub-pixels.

[0069] refer to Figure 4 c), this step is to perform the subsequent sub-pixel preparation process on the basis of the buffer pattern 21. Among them, the material of the organic light-emitting layer 30 and the material of the second electrode 40 are not limited here. Thus, in step S130, a sub-pixel 100 can be formed on the silicon-based circuit substrate 10 corresponding to each first electrode 11. By driving the silicon-based circuit substrate 10, the switch and brightness of the silicon-based organic electroluminescent microdisplay can be controlled, so that functions such as lighting and display can be performed.

[0070] The method for preparing a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention forms a buffer layer on multiple first electrodes on a silicon-based circuit substrate through an aqueous solution of a buffer material, and then patterns the buffer layer to form multiple buffer graphics, which are stacked up and down in a one-to-one correspondence with the first electrodes, and finally, on the side of each buffer graphic away from the first electrode, an organic light-emitting layer and a second electrode are sequentially formed to form multiple sub-pixels, thereby improving the surface work function of the first electrode, reducing the potential barrier between the first electrode and the organic layer, and ensuring the performance of the silicon-based organic electroluminescent microdisplay. The embodiment of the present invention solves the problem of lateral leakage between sub-pixels in existing silicon-based organic electroluminescent microdisplays, can avoid cross-coloring between sub-pixels, and can also improve the hole injection capacity of the sub-pixels, improve the recombination efficiency of carriers, and enhance the luminous efficiency of the sub-pixels.

[0071] It should be noted that the buffer material used in the above embodiment is a water-soluble buffer material, and the buffer layer is prepared by an aqueous solution of the buffer material. Specifically, the buffer material can be PEDOT:PSS, or a transition metal oxide, such as molybdenum oxide, tungsten oxide, vanadium oxide, copper oxide, etc. Of course, it can also be a mixture of two buffer materials, which is not limited here. In addition, illustratively, the material of the first electrode can be specifically selected from at least one of aluminum, titanium, molybdenum or titanium nitride.

[0072] In addition, it should be noted that the silicon-based organic electroluminescent microdisplay provided in the embodiment of the present invention can be used to prepare a display screen of a certain size. In actual application scenarios, the preparation process of the silicon-based organic electroluminescent microdisplay also includes a packaging and color matching process. Specifically, in step S130, on the side of each buffer pattern away from the first electrode, an organic light-emitting layer and a second electrode are sequentially formed to form a plurality of sub-pixels, and then, Figure 4 d), the method for preparing the silicon-based organic electroluminescent microdisplay further comprises:

[0073] S140, forming an encapsulation layer, a color filter layer and a cover glass in sequence on a side of the sub-pixel away from the silicon-based circuit substrate.

[0074] Among them, the encapsulation layer 50 is made of pure inorganic materials, such as a laminated structure of SiO / SiN / Al2O3, or an inorganic / organic / inorganic laminated structure can also be used, and its specific materials are not limited. The encapsulation layer 50 is used to seal and protect each sub-pixel 100 to prevent it from being eroded by air and water vapor, thereby ensuring that the organic material in the sub-pixel 100 will not deteriorate and ensuring efficient luminous efficiency. The color filter layer 60 is a color filter point added to each sub-pixel 100, through which the color of the light emitted by the sub-pixel 100 can be converted. As shown in the figure, three adjacent sub-pixels 100 can be respectively set with three color filter points of red, green and blue, so that three sub-pixels are formed by sub-pixels 100 of red, green and blue colors, so as to match colors and present a full-color display screen. Furthermore, when preparing the silicon-based organic electroluminescent microdisplay, cutting, patching and other processes will also be performed, which will not be described in detail here.

[0075] As described in the background technology section, when preparing wafers, existing wafer factories will form CMOS bottom layer circuits on them, and at the same time, they will also prepare the anodes of sub-pixels. At this time, the silicon-based circuit substrate provided in the above embodiment includes a silicon-based substrate and a driving circuit located on the silicon-based substrate, and the driving circuit includes a plurality of first electrodes. In view of this situation, an embodiment of the present invention provides a specific method for preparing a silicon-based organic electroluminescent microdisplay. Figure 5 is a flow chart of another method for preparing a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention, Figure 6 yes Figure 5 The structural flow chart of the method for preparing a silicon-based organic electroluminescent microdisplay is shown in FIG. Figure 5 and Figure 6 The method for preparing the silicon-based organic electroluminescent microdisplay comprises:

[0076] S210, forming a photoresist pattern on a silicon-based circuit substrate, wherein the photoresist in the photoresist pattern is located between any two adjacent first electrodes, and a surface of the first electrode facing away from the silicon-based substrate is flush with a surface of the photoresist pattern facing away from the silicon-based substrate; and a plurality of first electrodes are insulated from each other and evenly arranged on the silicon-based circuit substrate.

[0077] refer to Figure 6 As shown in FIG. a), this step is essentially a process of filling photoresist between the first electrodes 11 of the silicon-based circuit substrate 10, and the gap pattern between the first electrodes 11 is the photoresist pattern 71.

[0078] S220 , coating an aqueous solution of a buffer material on the photoresist pattern and the plurality of first electrodes to form a buffer layer.

[0079] refer to Figure 6As shown in Figure b), when the aqueous solution of the buffer material is coated on the silicon-based circuit substrate 10 by spin coating, spray coating and other processes, the water solvent will evaporate, and the buffer material retained on the silicon-based circuit substrate 10 can form a uniform buffer layer 20. After this step, in order to ensure that the water in the aqueous solution evaporates fully, avoid water contamination and corrosion of the organic light-emitting material, and solidify the buffer layer at the same time to ensure the hole injection ability of the buffer layer 20, it is also necessary to anneal the buffer layer 20. Specifically, when the buffer layer is annealed, the annealing temperature can be set at 80-250°C, and the annealing time can be set at 30min-2h. Preferably, the annealing temperature can be set to 120°C and the annealing time can be set to 30min.

[0080] S230, using an oil-soluble organic solvent to dissolve the photoresist pattern and the film layer on the photoresist pattern to form a plurality of buffer patterns; the buffer patterns and the first electrodes are stacked up and down in a one-to-one correspondence.

[0081] refer to Figure 6 As shown in Figure c), this step is the process of stripping the photoresist pattern 71 between the first electrodes 11, and at the same time, the buffer layer formed on the photoresist pattern 71 will also be detached. At this time, the structure remaining on the silicon-based circuit substrate 10 is only the first electrode 11 and the buffer pattern 21 located on the first electrode 11. In other words, the buffer layer 20 located thereon can be patterned using the patterned photoresist pattern 71, and after stripping the photoresist pattern 71, the corresponding buffer pattern 21 is finally formed on the upper surface of the first electrode 11 for preparing sub-pixels. Exemplarily, the oil-soluble organic solvent can generally use organic compounds such as N-methylpyrrolidone.

[0082] S240, forming an organic light-emitting layer and a second electrode in sequence on a side of each buffer pattern away from the first electrode to form a plurality of sub-pixels.

[0083] S250, forming an encapsulation layer, a color filter layer and a cover glass in sequence on a side of the sub-pixel away from the silicon-based circuit substrate.

[0084] refer to Figure 6 d) and e) of the figure, these two steps are the process of subsequent preparation of the silicon-based organic electroluminescent microdisplay based on the first electrode and the buffer pattern, which will not be repeated here.

[0085] Specifically, in the process of forming the photoresist pattern in step S210, the following steps may also be included:

[0086] S211 , forming a photoresist layer on the silicon-based circuit substrate, wherein the photoresist layer covers the first electrode 11 and the silicon-based substrate 12 .

[0087] The photoresist layer can be made of positive photoresist or negative photoresist material, and covers the first electrode 11 and the silicon-based substrate 12 to ensure the filling of the gap between the first electrodes 11 and facilitate the preparation of subsequent photoresist patterns.

[0088] S212, curing the photoresist layer.

[0089] The curing process may be ultraviolet curing or plasma curing. It is understandable that the curing process of the photoresist layer mainly depends on the material of the photoresist layer, and no further restrictions are made here.

[0090] S213, exposing and developing the photoresist layer to form a photoresist pattern.

[0091] This step is essentially a process of thinning the photoresist layer using a developer after exposing the photoresist layer. After being gradually thinned, the photoresist layer becomes the shape of the photoresist pattern 71 .

[0092] In another embodiment of the present invention, although the wafer provided by the existing wafer factory forms the CMOS bottom layer circuit, the anode of the sub-pixel is not formed therein, that is, the silicon-based circuit substrate includes a silicon-based substrate and a driving circuit located on the silicon-based substrate, and the driving circuit includes a plurality of guide electrodes. Among them, the guide electrode is actually a tungsten hole formed on the wafer, and the tungsten hole is used as a guide electrode to be electrically connected to the electrode of the sub-pixel. Based on this, the embodiment of the present invention also provides a specific method for preparing a silicon-based organic electroluminescent microdisplay. Figure 7 is a flow chart of another method for preparing a silicon-based organic electroluminescent microdisplay provided by an embodiment of the present invention, Figure 8 yes Figure 5 The structural flow chart of the method for preparing a silicon-based organic electroluminescent microdisplay is shown in FIG. Figure 5 and Figure 8 The method for preparing the silicon-based organic electroluminescent microdisplay comprises:

[0093] S310, forming a photoresist pattern on a silicon-based circuit substrate, wherein the photoresist in the photoresist pattern is located between any two adjacent guide electrodes; and a plurality of first electrodes are insulated from each other and evenly arranged on the silicon-based circuit substrate.

[0094] refer to Figure 8 As shown in FIG. a), this step is essentially a process of adding a photoresist pattern between the guide electrodes 13 of the silicon-based circuit substrate 10, and the area between the guide electrodes 13 is the photoresist pattern 71. In other words, after the photoresist pattern 71 is formed in this step, the hollowed-out area in the photoresist pattern 71 is the area where the guide electrode 13 is located.

[0095] S320, forming a first electrode layer on the photoresist pattern and the guide electrode.

[0096] refer to Figure 8 As shown in FIG. b), at this time, the first electrode layer 80 covers the photoresist pattern 71 and fills the hollowed-out area of ​​the photoresist pattern 71. At this time, the first electrode layer 80 is electrically connected to each guide electrode 13 in the hollowed-out area.

[0097] S330 , coating an aqueous solution of a buffer material on the first electrode layer to form a buffer layer.

[0098] refer to Figure 8 c), similarly, this step is a process of preparing a buffer layer by spin coating or spray coating. After this step, the buffer layer 20 needs to be annealed to solidify the buffer layer 20 and remove the water vapor therein to avoid corrosion of the organic light-emitting material. The annealing temperature can be set to 80-250°C, and the annealing time can be set to 30min-2h.

[0099] S340, using an oil-soluble organic solvent to dissolve the photoresist pattern and the film layer on the photoresist pattern to form a plurality of buffer patterns; the buffer patterns and the first electrodes are stacked up and down in a one-to-one correspondence.

[0100] refer to Figure 8 d), similarly, this step is a process of stripping the photoresist pattern 71, and at the same time, the first electrode layer 80 and the buffer layer 20 formed on the photoresist pattern 71 will also be detached. At this time, the only structure remaining on the silicon-based circuit substrate 10 is the first electrode 11 and the buffer pattern 21 located on the first electrode 11. In other words, the first electrode layer 80 and the buffer layer 20 located thereon can be patterned using the patterned photoresist pattern 71, and after stripping the photoresist pattern 71, a plurality of first electrodes 11 and corresponding buffer patterns 21 are finally formed, thereby being used to prepare sub-pixels.

[0101] S350, forming an organic light-emitting layer and a second electrode in sequence on a side of each buffer pattern away from the first electrode to form a plurality of sub-pixels.

[0102] S360, forming an encapsulation layer, a color filter layer and a cover glass in sequence on a side of the sub-pixel away from the silicon-based circuit substrate.

[0103] refer to Figure 8 As shown in Figure e) and Figure f), these two steps are the process of preparing the subsequent silicon-based organic electroluminescent microdisplay based on the first electrode and the buffer pattern, which will not be described in detail here.

[0104] Similarly, the process of forming the photoresist pattern in the above step S310 may specifically include:

[0105] S311, forming a photoresist layer on the silicon-based circuit substrate, wherein the photoresist layer covers the guide electrode and the silicon-based substrate;

[0106] The photoresist layer can be made of positive photoresist or negative photoresist material, and the photoresist layer covers the guide electrode 13 and the silicon-based substrate 12 .

[0107] S312, curing the photoresist layer.

[0108] The curing process may be ultraviolet curing or plasma curing. It is understandable that the curing process of the photoresist layer mainly depends on the material of the photoresist layer, and no further restrictions are made here.

[0109] S313, exposing and developing the photoresist layer to form a photoresist pattern.

[0110] This step requires the use of a photomask to expose the photoresist, and then develop it, that is, use a developer to wash away part of the photoresist. It should be noted that the pattern of the photomask in this step determines the photoresist pattern. Taking positive photoresist as an example, the exposed area can be removed by a developer. Therefore, the pattern of the photomask needs to be set to be consistent with the target photoresist pattern, so as to achieve the pattern transfer from the photomask to the photoresist layer.

[0111] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A silicon-based organic electroluminescent microdisplay, characterized in that: include: A silicon-based circuit substrate, the silicon-based circuit substrate comprising a silicon-based substrate and a driving circuit located on the silicon-based substrate; A plurality of sub-pixels, wherein the sub-pixels are arranged on the silicon-based circuit substrate, and the sub-pixels include a first electrode, a buffer pattern, an organic light-emitting layer, and a second electrode which are sequentially stacked, and the first electrode is electrically connected to the driving circuit; The buffer pattern is formed by patterning a buffer layer, and the buffer layer is prepared by using an aqueous solution of a buffer material; a photoresist pattern is formed on the silicon-based circuit substrate, the photoresist in the photoresist pattern is located between any two adjacent first electrodes, and the surface of the first electrode facing away from the silicon-based substrate is flush with the surface of the photoresist pattern facing away from the silicon-based substrate, and the photoresist pattern and the film layer on the photoresist pattern are dissolved to form a plurality of the buffer patterns; It also includes an encapsulation layer, a color filter layer and a cover glass which are stacked in sequence, wherein the color filter layer includes a plurality of color filter dots; The encapsulation layer is located on a side of the plurality of sub-pixels away from the silicon-based circuit substrate and covers the plurality of sub-pixels; The color filter layer is located on a side of the encapsulation layer away from the sub-pixels, and the plurality of color filter dots correspond one-to-one to the plurality of sub-pixels; The cover glass is located on a side of the color filter layer away from the encapsulation layer; The organic light-emitting layer and the second electrode are sequentially formed on a side of each buffer pattern away from the first electrode to form a plurality of sub-pixels.

2. A method for preparing a silicon-based organic electroluminescent microdisplay, for preparing the silicon-based organic electroluminescent microdisplay as claimed in claim 1, characterized in that: The silicon-based circuit substrate comprises a silicon-based substrate and a driving circuit located on the silicon-based substrate, wherein the driving circuit comprises a plurality of the first electrodes, including: Forming a photoresist pattern on the silicon-based circuit substrate, wherein the photoresist in the photoresist pattern is located between any two adjacent first electrodes, a surface of the first electrode facing away from the silicon-based substrate is flush with a surface of the photoresist pattern facing away from the silicon-based substrate, and the plurality of first electrodes are evenly arranged on the silicon-based circuit substrate; coating an aqueous solution of a buffer material on the photoresist pattern and the plurality of first electrodes to form a buffer layer; Using an oil-soluble organic solvent to dissolve the photoresist pattern and peel off the film layer on the photoresist pattern to form a plurality of buffer patterns, wherein the buffer patterns correspond to the first electrodes and are stacked up and down in a one-to-one manner; On a side of each of the buffer patterns away from the first electrode, an organic light-emitting layer and a second electrode are sequentially formed to form a plurality of sub-pixels; On the side of the sub-pixel away from the silicon-based circuit substrate, a packaging layer, a color filter layer and a cover glass are formed in sequence.

3. The method for preparing a silicon-based organic electroluminescent microdisplay according to claim 2, characterized in that: Forming a photoresist pattern on the silicon-based circuit substrate comprises: forming a photoresist layer on the silicon-based circuit substrate, wherein the photoresist layer covers the first electrode and the silicon-based substrate; curing the photoresist layer; The photoresist layer is exposed and developed to form the photoresist pattern.

4. The method for preparing a silicon-based organic electroluminescent microdisplay according to claim 2, characterized in that: The silicon-based circuit substrate comprises a silicon-based substrate and a driving circuit located on the silicon-based substrate, wherein the driving circuit comprises a plurality of guiding electrodes; A buffer layer is formed on a plurality of first electrodes on a silicon-based circuit substrate using an aqueous solution of a buffer material, comprising: Forming a photoresist pattern on the silicon-based circuit substrate, wherein the photoresist in the photoresist pattern is located between any two adjacent guide electrodes; forming a first electrode layer on the photoresist pattern and the guide electrode; coating an aqueous solution of a buffer material on the first electrode layer to form a buffer layer; The buffer layer is patterned to form a plurality of buffer patterns, including: An oil-soluble organic solvent is used to dissolve the photoresist pattern and the film layer on the photoresist pattern to form a plurality of buffer patterns.

5. The method for preparing a silicon-based organic electroluminescent microdisplay according to claim 4, characterized in that: Forming a photoresist pattern on the silicon-based circuit substrate comprises: forming a photoresist layer on the silicon-based circuit substrate, wherein the photoresist layer covers the guide electrode and the silicon-based substrate; curing the photoresist layer; The photoresist layer is exposed and developed to form the photoresist pattern.

6. The method for preparing a silicon-based organic electroluminescent microdisplay according to claim 2 or 4, characterized in that: Before using an oil-soluble organic solvent to dissolve the photoresist pattern and peel off the film layer on the photoresist pattern to form a plurality of buffer patterns, the preparation method further includes: The buffer layer is annealed.

7. The method for preparing a silicon-based organic electroluminescent microdisplay according to claim 6, characterized in that: The annealing temperature of the annealing treatment is 80-250° C., and the annealing time is 30 min-2 h.

Images