Fabrication methods and light-emitting devices for light-emitting devices

Abstract

This application relates to the field of display technology, and in particular to a method for fabricating a light-emitting device and a light-emitting apparatus. The method for fabricating the light-emitting device includes: forming a pixel defining layer on a substrate, the pixel defining layer having multiple pixel openings, the pixel openings being of a first type and a second type; forming a functional layer in the first type of opening; forming a first light-emitting layer on the functional layer in the first type of opening; and sequentially stacking a functional supplementary layer and a second light-emitting layer in the second type of opening, wherein the first light-emitting layer and the second light-emitting layer are made of different materials. This addresses the problem in related technologies where, when fabricating light-emitting devices by inkjet printing, ink droplets from a light-emitting layer of a certain color prepared in a previous fabrication step easily fall into the light-emitting layer of a sub-pixel of another color prepared in a subsequent fabrication step, thus hindering the improvement of the luminous efficiency of the sub-pixel of another color prepared in the subsequent fabrication step.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method for preparing a light-emitting device and a light-emitting apparatus. Background Technology

[0002] Display technology has made one qualitative leap after another, from early cathode ray tube (CRT) displays to liquid crystal displays (LCDs) and plasma display panels (PDPs) in the mid-1980s, and now to the mainstream OLED (Organic Light-Emitting Diode) and QLED (Quantum Dot Light-Emitting Diodes) displays.

[0003] Currently, OLED and QLED, each with their own advantages, are increasingly becoming research hotspots in display technology. For both OLED and QLED light-emitting devices, given the ease of material deposition, they can be manufactured using inkjet printing, reducing the waste of raw materials and substrate sagging issues associated with vapor deposition processes.

[0004] However, to ensure display quality, the spacing between red, green, and blue subpixels in full-color light-emitting devices is relatively small. This means that when using inkjet printing to fabricate the light-emitting layers of OLED and QLED devices, ink droplets from a certain color layer prepared in a previous fabrication step may fall into the light-emitting layer of a different color subpixel prepared in a subsequent fabrication step during the drying process. This affects the luminous efficiency of the subpixel of the other color prepared in the subsequent fabrication step, which is detrimental to improving the overall luminous efficiency of the light-emitting device. Furthermore, the reduced luminous efficiency of the subpixel of the other color prepared in the subsequent fabrication step can cause uneven color matching in the full-color light-emitting device, which may lead to problems such as color shift. Summary of the Invention

[0005] Based on this, this application provides a method for fabricating a light-emitting device and a light-emitting apparatus to solve the problem in related technologies where, when fabricating a light-emitting device by inkjet printing, ink droplets of a certain color light-emitting layer prepared in the previous fabrication step easily fall into the light-emitting layer of another color sub-pixel prepared in the subsequent fabrication step, thus hindering the improvement of the light-emitting efficiency of the other color sub-pixel prepared in the subsequent fabrication step.

[0006] Firstly, a method for fabricating a light-emitting device is provided, comprising:

[0007] A pixel defining layer is formed on a substrate. The pixel defining layer has multiple pixel openings, and the types of pixel openings include a first type of opening and a second type of opening.

[0008] A functional layer is formed in the first type of opening;

[0009] A first light-emitting layer is formed on the functional layer in the first type of opening;

[0010] A functional supplementary layer and a second light-emitting layer are sequentially stacked in the second type of opening;

[0011] The first and second light-emitting layers are made of different materials.

[0012] Optionally, prior to the step of forming the first light-emitting layer on the functional layer in the first type of opening, the method includes:

[0013] The functional layer is formed in the second type of opening;

[0014] The thickness of the functional layer in the first type of opening is greater than the thickness of the functional layer in the second type of opening.

[0015] Optionally, the thickness of the functional supplement layer is greater than 10 nm; and / or, the thickness of the functional layer located in the first type of opening is equal to the total thickness of the functional layer and the functional supplement layer located in the second type of opening; and / or

[0016] The material of the functional layer is the same as the material of the functional supplement layer.

[0017] Optionally, forming a first light-emitting layer in the first type of opening includes:

[0018] A first light-emitting precursor layer is formed in the first type of opening by inkjet printing, the first light-emitting precursor layer containing a first light-emitting material and a first solvent.

[0019] A first solvent layer containing a first solvent is formed in a second type of opening by inkjet printing.

[0020] The first luminescent layer is prepared by removing the first solvent from the first type of opening and the second type of opening through a drying process.

[0021] Optionally, the upper surface of the first solvent in the second type of opening is not higher than the upper surface of the second type of opening.

[0022] Optionally, the pixel aperture type further includes: a third type aperture; prior to the step of forming the first light-emitting layer on the functional layer in the first type aperture, the method further includes:

[0023] The functional layer is formed in the third type of opening;

[0024] The thickness of the functional layer in the first type of opening is greater than the thickness of the functional layer in the third type of opening.

[0025] Optionally, before removing the first solvent from the first type of opening and the second type of opening by drying, the process further includes:

[0026] A first solvent layer containing a first solvent is formed in a third type of opening by inkjet printing.

[0027] Optionally, after forming the first light-emitting layer on the functional layer in the first type of opening, the method further includes:

[0028] A functional supplement layer and a third light-emitting layer are formed sequentially on the functional layer in the third type of opening.

[0029] Optionally, the color of the first light-emitting layer is blue; and / or

[0030] One of the second and third luminescent layers is either green or red, and the other of the second and third luminescent layers is either green or red; and / or

[0031] The first, second, and third light-emitting layers are formed independently by inkjet printing; and / or,

[0032] The functional layer and the functional supplementary layer are independently material layers with hole transport function or material layers with electron transport function; and / or

[0033] The functional layer and the supplementary functional layer are formed independently by inkjet printing.

[0034] Optionally, both the first and second light-emitting layers are made of organic light-emitting materials;

[0035] Alternatively, both the first and second light-emitting layers can be made of quantum dot light-emitting materials.

[0036] Secondly, a light-emitting device is provided, comprising:

[0037] The light-emitting device is prepared by the method described in the first aspect.

[0038] Compared with the prior art, this application has the following beneficial effects:

[0039] By employing a two-step method to form the first sub-pixel and the second sub-pixel respectively, on the one hand, when forming the first light-emitting layer contained in the first sub-pixel, the ink droplets of the first light-emitting layer can fall into the hole transport layer contained in the second sub-pixel or between the hole transport layer and the substrate, rather than into the second light-emitting layer contained in the second sub-pixel. That is, due to the isolation of the functional supplement layer, when emitting light, electrons in the second sub-pixel will not be injected through the functional supplement layer into the ink droplets that fall into the second type of opening in the first light-emitting layer, thus preventing the ink droplets that fall into the second type of opening in the first light-emitting layer from emitting light. On the other hand, due to the isolation of the functional supplement layer, electrons and holes can recombine in the second light-emitting layer as much as possible, thereby improving the luminous efficiency of the second sub-pixel and thus improving the overall luminous efficiency of the light-emitting device.

[0040] As the luminous efficiency of the second sub-pixel increases, and the ink droplets of the first luminous layer do not emit light at the location of the second sub-pixel, it is beneficial to improve the luminous purity of the second sub-pixel. This can effectively improve the overall luminous purity and luminous uniformity of the light-emitting device, thereby reducing problems such as color shift.

[0041] In addition, compared with related technologies that reduce the above-mentioned defects by improving the materials of the first and second light-emitting layers, which involves a long material development cycle and high difficulty, this preparation method is simple, low-cost, and can effectively solve the above-mentioned defects, improve the luminous efficiency of the light-emitting device, and has good repeatability, reliability and operational stability. Attached Figure Description

[0042] Figure 1 This is a cross-sectional structural diagram of a light-emitting device provided in an embodiment of this application;

[0043] Figure 2 A schematic flowchart illustrating a method for fabricating a light-emitting device according to an embodiment of this application;

[0044] Figure 3 This is a schematic flowchart illustrating another method for fabricating a light-emitting device provided in an embodiment of this application. Detailed Implementation

[0045] The present application will be further described in detail below with reference to specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] Based on the above technical problems, some embodiments of this application provide a method for fabricating a light-emitting device 10, such as... Figure 1 As shown, the light-emitting device 10 includes: a plurality of pixel units P, each pixel unit P including a first sub-pixel P1 and a second sub-pixel P2. Figure 1 , Figure 2 and Figure 3 As shown, the above preparation method includes:

[0048] S1. A pixel defining layer 2 is formed on a substrate 1 (e.g., a TFT substrate). The pixel defining layer 2 has multiple pixel openings K, which can be arranged in an array. The types of pixel openings K include a first type opening K1 and a second type opening K2, wherein the first type opening K1 corresponds to a first sub-pixel P1, and the second type opening K2 corresponds to a second sub-pixel P2.

[0049] S2, forming a functional layer 31 in the first type of opening K1.

[0050] S3. A first light-emitting layer 41 is formed on the functional layer 31 in the first type of opening K1.

[0051] S4. A functional supplementary layer 33 and a second light-emitting layer 42 are sequentially stacked in the second type of opening K2. The first light-emitting layer 41 and the second light-emitting layer 42 are made of different materials.

[0052] The colors of the first light-emitting layer 41 and the second light-emitting layer 42 are not specifically limited, and the first light-emitting layer 41 and the second light-emitting layer 42 can be any two different colors.

[0053] In some embodiments, the color of the first light-emitting layer may be blue, in which case the color of the second light-emitting layer may be green or red.

[0054] In some embodiments, the first light-emitting layer 41 and the second light-emitting layer 42 can be formed independently by inkjet printing.

[0055] In some embodiments, the functional layer 31 and the functional supplementary layer 33 are respectively independently material layers with hole transport function or material layers with electron transport function.

[0056] When functional layer 31 and functional supplementary layer 33 are each independently material layers with hole transport function, both functional layer 31 and functional supplementary layer 33 can be hole transport layers. When functional layer 31 and functional supplementary layer 33 are each independently material layers with electron transport function, both functional layer 31 and functional supplementary layer 33 can be electron transport layers.

[0057] In the following embodiments, the functional layer 31 and the functional supplementary layer 33 are each described as material layers with hole transport function independently.

[0058] At this point, both functional layer 31 and functional supplementary layer 33 are hole transport layers, and functional layer 31 and functional supplementary layer 33 can be formed independently by inkjet printing.

[0059] In the fabrication method of the light-emitting device provided in this application embodiment, by adopting a two-step method to form the hole transport layer contained in the first sub-pixel P1 and the second sub-pixel P2 respectively, on the one hand, when forming the first light-emitting layer 41 contained in the first sub-pixel P1, the ink droplets of the first light-emitting layer 41 can fall into the hole transport layer contained in the second sub-pixel P2 or between the hole transport layer and the substrate 1, rather than into the second light-emitting layer 42 contained in the second sub-pixel P2. That is, due to the isolation of the functional supplement layer 33, when emitting light, the electrons in the second sub-pixel P2 will not be injected into the ink droplets that fall into the second type opening K2 through the functional supplement layer 33, so that the ink droplets that fall into the second type opening K2 of the first light-emitting layer 41 will not emit light. On the other hand, due to the isolation of the functional supplement layer 33, electrons and holes can recombine in the second light-emitting layer 42 as much as possible, thereby improving the luminous efficiency of the second sub-pixel P2, and thus improving the overall luminous efficiency of the light-emitting device.

[0060] As the luminous efficiency of the second sub-pixel P2 increases, and the ink droplets of the first luminous layer 41 do not emit light at the location of the second sub-pixel P, it is beneficial to improve the luminous purity of the second sub-pixel P2, thereby effectively improving the overall luminous purity and luminous uniformity of the light-emitting device, and thus reducing problems such as color shift.

[0061] In addition, compared with the related technologies that reduce the above-mentioned defects by improving the materials of the first light-emitting layer 41 and the second light-emitting layer 42, which involves a long material development cycle and high difficulty, this preparation method is simple, low-cost, and can effectively solve the above-mentioned defects, improve the luminous efficiency of the light-emitting device, and the preparation method has good repeatability, reliability and operational stability.

[0062] Before forming the functional supplementary layer 33 as described above, a partial functional layer or no functional layer may be formed in the second type of opening K2.

[0063] When a partial functional layer is formed in the second type of opening K2, the partial functional layer and the functional supplementary layer 33 together form the hole transport layer in the second type of opening K2. When no functional layer is formed in the second type of opening K2, the functional supplementary layer forms the hole transport layer in the second type of opening K2.

[0064] In some embodiments, prior to the step of forming the first light-emitting layer 41 on the functional layer in the first type of opening K1, the method includes:

[0065] A functional layer 32 is formed in the second type of opening K2;

[0066] The thickness of the functional layer in the first type of opening K1 is greater than the thickness of the functional layer in the second type of opening K2.

[0067] In these embodiments, before forming the first light-emitting layer 41 on the functional layer in the first type opening K1, the functional layer 32 is formed in the second type opening K2. Since the thickness of the functional layer in the first type opening K1 is greater than the thickness of the functional layer in the second type opening K2, the thickness of the hole transport layer finally formed in the second type opening K2 is not too large when the functional supplementary layer 33 is subsequently formed in the second type opening K2.

[0068] In some embodiments, the formation of functional layer 32 in the second type opening K2 and the formation of functional layer 31 in the first type opening K1 can be performed simultaneously.

[0069] The thickness of the aforementioned functional supplementary layer 33 is not specifically limited, as long as the thickness of the functional layer 31 is greater than the thickness of the functional supplementary layer 33, so that the functional supplementary layer 33 can block the ink droplets injected by electrons that fall into the first light-emitting layer 41 of the second sub-pixel.

[0070] In some embodiments, the thickness of the functional supplement layer 33 is greater than 10 nm; and / or, the thickness of the functional layer 31 located in the first type opening K1 is equal to the total thickness of the functional layer 32 and the functional supplement layer 33 located in the second type opening K2; and / or, the material of the functional layer and the material of the functional supplement layer are the same, for example, the materials of the functional layer 31 and the functional layer 32 are the same as the material of the functional supplement layer 33.

[0071] In these embodiments, when the thickness of the functional supplementary layer 33 is greater than 10 nm, it can be ensured that the functional supplementary layer 33 has sufficient thickness to block ink droplets injected into the first light-emitting layer 41 of the second sub-pixel, thereby effectively improving the luminous efficiency of the second sub-pixel. Furthermore, by making the thickness of the functional layer 31 located in the first type opening K1 equal to the total thickness of the functional layer 32 and the functional supplementary layer 33 located in the second type opening K2, the problems of excessively thick or thin hole transport layer in the second type opening K2 can be avoided. If the hole transport layer in the second type opening K2 is too thick, it is detrimental to the process control of the hole transport layer; if the hole transport layer in the second type opening K2 is too thin, it is detrimental to maintaining a large thickness of the subsequent functional supplementary layer 33, thus hindering the blocking of ink droplets injected into the first light-emitting layer 41 of the second sub-pixel.

[0072] Of course, in some embodiments, the thickness of the functional layer 31 in the first type opening K1 may be different from the sum of the thicknesses of the functional layer 32 and the functional supplementary layer 33 in the second type opening K2.

[0073] Regardless of whether the thickness of the aforementioned functional layer 31 is the same as the sum of the thicknesses of functional layer 32 and functional supplementary layer 33, under naked-eye observation, functional layer 32 and functional supplementary layer 33 are tightly connected and neither has any steps.

[0074] In some embodiments, the thickness of the hole transport layer contained in the first subpixel P1 and the second subpixel P2 is 15 to 180 nm.

[0075] At this point, the thickness of the functional layer 31 can be in the range of 15 to 180 nm, and the sum of the thicknesses of the functional layer 32 and the functional supplementary layer 33 can also be in the range of 15 to 180 nm.

[0076] In other embodiments, the thickness of the first light-emitting layer 41 may be the same as the thickness of the second light-emitting layer 42.

[0077] In some embodiments, prior to S2, the method may further include forming a hole injection layer 30 in a plurality of pixel openings K.

[0078] The light-emitting device 10 mentioned above can be an OLED light-emitting device or a QLED light-emitting device, and no specific limitation is made here.

[0079] In some embodiments, when the light-emitting device 10 is an OLED light-emitting device, the materials of the first light-emitting layer 41 and the second light-emitting layer 42 can both be organic light-emitting materials. In other embodiments, when the light-emitting device 10 is a QLED light-emitting device, the materials of the first light-emitting layer 41 and the second light-emitting layer 42 can both be quantum dot light-emitting materials.

[0080] In the following embodiments, this application will be described using an OLED light-emitting device as an example.

[0081] In some embodiments, S3, a first light-emitting layer 41 is formed in the first type of opening K1, such as Figure 3 As shown, it includes:

[0082] S31. A first light-emitting precursor layer 100 is formed in a first type opening K1 by inkjet printing. The first light-emitting precursor layer 100 contains a first light-emitting material and a first solvent.

[0083] S32. A first solvent layer 200 containing a first solvent is formed in a second type opening K2 by inkjet printing; the second type opening K2 does not contain the first light-emitting material contained in the first light-emitting precursor layer 100.

[0084] S33. The first solvent in the first type opening K1 and the second type opening K2 is removed by drying to prepare the first light-emitting layer 41.

[0085] In these embodiments, a first solvent layer 200 containing a first solvent is formed in the second type opening K2, and the first solvent layer 200 is removed while the first solvent in the first type opening K1 is removed by drying, thereby forming a first light-emitting layer 41. During this process, the first solvent in the second type opening K2 will evaporate and remove the ink droplets that fall into the second type opening K2, thereby removing the ink droplets that fall into the second type opening K2, thereby reducing the residue of the first light-emitting layer 41 at the location of the second sub-pixel P2, and further improving the light-emitting efficiency of the second sub-pixel P2.

[0086] There is no specific limitation on the order of S32 and S31. S32 and S31 can be performed in sequence or simultaneously. When performed simultaneously, inkjet printing of some nozzles of the same printhead forms the first light-emitting precursor layer, and inkjet printing of some nozzles forms the first solvent layer 200.

[0087] In some embodiments, the upper surface of the first solvent in the second type opening K2 is not higher than the upper surface of the second type opening K2. Therefore, the first solvent will not overflow from the second type opening K2.

[0088] In these embodiments, by ensuring that the upper surface of the first solvent in the second type opening K2 is not higher than the upper surface of the second type opening K2, the first solvent in the second type opening K2 can be filled as much as possible without overflowing, thereby making it easier to remove the ink droplets that the first light-emitting layer 41 has fallen into the second type opening K2.

[0089] In some embodiments, the pixel aperture type further includes: a third type aperture; before the step of forming the first light-emitting layer 41 on the functional layer 31 in the first type aperture K1, the method further includes: forming a functional layer in the third type aperture, wherein the thickness d1 of the functional layer 31 in the first type aperture K1 is greater than the thickness of the functional layer in the third type aperture.

[0090] In these embodiments, the description of the functional layer in the third type of opening can be found in the above description of the functional layer in the second type of opening, and will not be repeated here.

[0091] In some embodiments, before removing the first solvent from the first type opening K1 and the second type opening K2 by drying, the method further includes: forming a first solvent layer containing the first solvent in the third type opening by inkjet printing. The order of this step with respect to S32 and S31 described above is not specifically limited; this step can be performed sequentially or simultaneously with S32 and S31. For related explanations, please refer to the descriptions of S32 and S31 above, which will not be repeated here.

[0092] In these embodiments, similar to the formation of a first solvent layer containing the first solvent in the second type of opening described above, by forming a first solvent layer containing the first solvent in the third type of opening before removing the first solvent in the first type of opening K1 and the second type of opening K2 through the drying process, the first solvent in the third type of opening can also be removed when the first solvent in the first type of opening K1 and the second type of opening K2 is removed through the subsequent drying process. This allows the ink droplets that fall from the first light-emitting layer to the location of the third sub-pixel to be removed as well. This reduces the amount of electrical energy absorbed by the third sub-pixel by the ink droplets that fall from the first light-emitting layer 41 into the third type of opening to emit light. Consequently, more electrons and holes can recombine in the light-emitting layer contained in the third sub-pixel to emit light, thereby improving the luminous efficiency of the third sub-pixel.

[0093] In some embodiments, after forming the first light-emitting layer 41 on the functional layer of the first type of opening K1, the method further includes: sequentially forming a functional supplementary layer and a third light-emitting layer on the functional layer of the third type of opening.

[0094] In these embodiments, the formation of a functional supplement layer and a third light-emitting layer on the functional layer of the third type of opening can be synchronized with the formation of a functional supplement layer and a second light-emitting layer 42 on the functional layer of the second type of opening. Thus, the functional supplement layer in the third type of opening has the same or similar function as the functional supplement layer in the second type of opening, which will not be elaborated here.

[0095] In some embodiments, similar to the functional supplementary layer in the second type of opening described above, the thickness of the functional supplementary layer in the third type of opening may also be greater than 10 nm.

[0096] The colors of the first light-emitting layer 41, the second light-emitting layer 42, and the third light-emitting layer are not specifically limited, and the first light-emitting layer 41, the second light-emitting layer 42, and the third light-emitting layer can have three different colors.

[0097] In some embodiments, the color of the first light-emitting layer 41 is blue; and / or, one of the second light-emitting layer 42 and the third light-emitting layer is one of green and red, and the other of the second light-emitting layer 42 and the third light-emitting layer is the other of green and red.

[0098] In these embodiments, for example, the second light-emitting layer 42 is green and the third light-emitting layer is red, or the second light-emitting layer 42 is red and the third light-emitting layer is green. Both of these methods can reduce the amount of ink droplets from the blue light-emitting layer falling into the green light-emitting layer, thereby effectively improving the luminous efficiency of the green sub-pixels and increasing the luminous color purity of the green sub-pixels, which in turn can reduce the color shift problem of the full-color display device.

[0099] Some embodiments of this application provide a light-emitting device, including a light-emitting device prepared by the preparation method described above.

[0100] Examples of such light-emitting devices include mobile phones, tablets, computers, or ATMs.

[0101] In the following examples and comparative examples, all raw materials were commercially available, and to maintain the reliability of the experiments, the raw materials used in the following examples and comparative examples had the same physical and chemical parameters or underwent the same treatment.

[0102] Example 1

[0103] The method for fabricating the light-emitting device provided in Example 1 is as follows:

[0104] Step 1) On a TFT substrate with a pixel definition layer, a hole injection layer for RGB pixels with a thickness of 50nm is prepared by inkjet printing.

[0105] Step 2) After the hole injection layer dries, inkjet print a hole transport layer and a light-emitting layer on top of the hole injection layer of the RGB pixel. The thickness of the hole transport layer for the red, green, and blue sub-pixels is 50 nm. The specific fabrication steps of the hole transport layer and the light-emitting layer are as follows:

[0106] 1) Inkjet print a 50nm hole transport layer in the pixel opening corresponding to the blue subpixel, and inkjet print a 10nm hole transport layer in the pixel opening of the green subpixel.

[0107] 2) After the hole transport layer in 1) dries, inkjet print blue luminescent ink into the pixel opening corresponding to the blue subpixel, and inkjet print the solvent of blue luminescent ink into the pixel opening corresponding to the green subpixel. The solvent does not overflow. After drying, the blue luminescent ink is prepared into a film to obtain the blue luminescent layer.

[0108] 3) A 40nm hole transport layer is inkjet printed in the pixel opening corresponding to the green subpixel.

[0109] 4) After the hole transport layer in 3) is dried, green luminescent ink is inkjet printed into the pixel opening corresponding to the green subpixel and then dried to prepare the green luminescent layer.

[0110] Step 3) After the light-emitting layer is prepared, an electron transport layer is formed by vapor deposition.

[0111] Step 4) A cathode and a light extraction layer (CPL) are formed on the electron transport layer by vapor deposition, thereby preparing a light-emitting device.

[0112] Comparative Example 1

[0113] The light-emitting device provided in Comparative Example 1 may consist of only green subpixels.

[0114] Comparative Example 2

[0115] The fabrication method of the light-emitting device provided in Comparative Example 2 is basically the same as that of the light-emitting device in Example 1. The difference is that the fabrication steps of the hole transport layer and the light-emitting layer in Comparative Example 2 are as follows:

[0116] 1) Inkjet print a 50nm hole transport layer in the pixel opening corresponding to the blue subpixel, and inkjet print a 50nm hole transport layer in the pixel opening of the green subpixel.

[0117] 2) After the hole transport layer in 1) dries, inkjet print blue luminescent ink into the pixel opening corresponding to the blue subpixel to prepare the blue luminescent layer.

[0118] 3) After the blue luminescent layer dries, inkjet print green luminescent ink into the pixel openings corresponding to the green subpixels to prepare the green luminescent layer.

[0119] The luminous performance tests of the green subpixels in the above embodiments and comparative examples are shown in Table 1 below:

[0120] Table 1

[0121]

[0122] CIEx represents the red component of the light emitted by the green subpixel in the CIE chromaticity diagram, and CIEx represents the green component of the light emitted by the green subpixel in the CIE chromaticity diagram. CE@J10 represents the current efficiency measured at a current density of 10 mA / cm², and T95@1000nit represents the lifetime when the brightness decays from 1000nit to 95%.

[0123] As shown in Table 1, compared to the monochromatic green subpixel, the light-emitting device prepared using the method of Comparative Example 2 suffers from lower luminous purity due to ink droplets from the blue emitting layer falling into the green emitting layer. However, the light-emitting device prepared using the method of Example 1 exhibits luminous purity comparable to that of the monochromatic green subpixel. This indicates that the method of Example 1 significantly reduces the impact of ink droplets from the blue emitting layer on the luminous emission of the green subpixel. Furthermore, the luminous efficiency of the light-emitting device prepared using the method of Comparative Example 2 is also significantly reduced, while the luminous efficiency of the green subpixel in the light-emitting device prepared using the method of Example 1 is essentially the same as that of the monochromatic green subpixel. Therefore, the method of Example 1 effectively improves the luminous efficiency of the green subpixel.

[0124] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0125] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for fabricating a light-emitting device, characterized in that, include: A pixel defining layer is formed on a substrate, the pixel defining layer having a plurality of pixel openings, the pixel openings including a first type of opening and a second type of opening; A functional layer is formed in the first type of opening; A first light-emitting layer is formed on the functional layer in the first type of opening; A functional supplementary layer and a second light-emitting layer are sequentially stacked in the second type of opening; The first light-emitting layer and the second light-emitting layer are made of different materials; the functional layer and the functional supplementary layer are material layers with hole transport function, or the functional layer and the functional supplementary layer are material layers with electron transport function. Prior to the step of forming a first light-emitting layer on the functional layer in the first type of opening, the method includes: The functional layer is formed in the second type of opening; The first light-emitting layer is blue.

2. The method according to claim 1, characterized in that, The thickness of the functional layer in the first type of opening is greater than the thickness of the functional layer in the second type of opening.

3. The method according to claim 2, characterized in that, The thickness of the functional supplementary layer is greater than 10 nm; and / or The thickness of the functional layer located in the first type of opening is equal to the total thickness of the functional layer and the functional supplementary layer located in the second type of opening; and / or The material of the functional layer is the same as the material of the functional supplement layer.

4. The method according to any one of claims 1 to 3, characterized in that, A first light-emitting layer is formed on the functional layer in the first type of opening, including: A first light-emitting precursor layer is formed in the first type of opening by inkjet printing, the first light-emitting precursor layer containing a first light-emitting material and a first solvent. A first solvent layer containing the first solvent is formed in the second type of opening by inkjet printing; The first light-emitting layer is prepared by removing the first solvent from the first type of opening and the second type of opening through a drying process.

5. The method according to claim 4, characterized in that, The upper surface of the first solvent layer in the second type of opening is not higher than the upper surface of the second type of opening.

6. The method according to claim 4, characterized in that, The pixel aperture type also includes a third type of aperture; prior to the step of forming a first light-emitting layer on the functional layer in the first type of aperture, the method further includes: The functional layer is formed in the third type of opening; The thickness of the functional layer in the first type of opening is greater than the thickness of the functional layer in the third type of opening.

7. The method according to claim 6, characterized in that, Before removing the first solvent from the first type of opening and the second type of opening by drying, the process further includes: The first solvent layer containing the first solvent is formed in the third type of opening by inkjet printing.

8. The method according to claim 6 or 7, characterized in that, After forming the first light-emitting layer on the functional layer in the first type of opening, the method further includes: The functional supplement layer and the third light-emitting layer are sequentially formed on the functional layer in the third type of opening.

9. The method according to claim 8, characterized in that, One of the second and third light-emitting layers is green and red, and the other of the second and third light-emitting layers is green and red; and / or The first light-emitting layer, the second light-emitting layer, and the third light-emitting layer are each formed independently by inkjet printing; and / or The functional layer and the supplementary functional layer are formed independently by inkjet printing.

10. The method according to claim 1, characterized in that, Both the first and second light-emitting layers are made of organic light-emitting materials.

11. The method according to claim 1, characterized in that, Both the first and second light-emitting layers are made of quantum dot light-emitting materials.

12. A light-emitting device, characterized in that, include: The light-emitting device prepared by the method according to any one of claims 1 to 11.

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