Light-emitting device and manufacturing method thereof, material screening method, and display panel

Abstract

The present invention discloses a light-emitting device and a manufacturing method thereof, a material screening method, and a display panel. The material screening method comprises: configuring at least two material groups, each material group comprises a main material and a dye, and at least one of the main material and the dye comprised in each two material groups is different from each other; using each material group as a light-emitting layer material, respectively manufacturing a single-carrier device; obtaining the defect energy between the main material and the dye in the single-carrier device corresponding to each material group; and screening a target material group from at least two material groups according to the defect energy corresponding to each material group, so as to be used as the light-emitting layer material of the light-emitting device. The present invention can effectively screen out a material combination that is suitable for the light-emitting layer of the light-emitting device and meets the requirements, and can reduce the start-up voltage of the light-emitting device.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a light-emitting device and a manufacturing method thereof, a material screening method, and a display panel. Background Art

[0002] Organic Light-Emitting Diode (OLED) is an electroluminescent device based on organic materials. Organic electroluminescence refers to the phenomenon that organic semiconductor materials and luminescent materials emit light through carrier injection and recombination under the drive of an electric field.

[0003] In full-color OLED displays, pixel crosstalk is prone to occur between red, green, and blue pixels. This problem mainly stems from the fact that the turn-on voltage of the blue light emitting device is significantly higher than that of the green and red light, resulting in a lateral current between the red, green, and blue pixels when the blue light is turned on, causing the red and green pixels to also emit light when the blue light is turned on. Studies have found that the selection of different luminescent materials will affect the turn-on voltage of the luminescent device. Therefore, it is necessary to provide a luminescent device and a method for screening the luminescent layer materials of the luminescent device. Summary of the invention

[0004] The embodiments of the present invention provide a light-emitting device and a manufacturing method thereof, a material screening method, and a display panel, which are intended to screen the light-emitting layer material of the light-emitting device.

[0005] In a first aspect, an embodiment of the present invention provides a light-emitting device, comprising: a light-emitting layer, comprising a main material and a dye doped in the main material; wherein, when carriers are injected into the light-emitting layer, there is defect energy between the main material and the dye, and the defect energy satisfies a preset value range.

[0006] According to the aforementioned embodiments of the first aspect of the present invention, the light-emitting device is a blue light-emitting device, and the defect energy is less than or equal to 0.04eV; the defect energy is less than or equal to 0.03eV; or, the light-emitting device is a red light-emitting device or a green light-emitting device, and the defect energy is greater than or equal to 0.03eV; the defect energy is between 0.03eV and 0.08eV.

[0007] In a second aspect, an embodiment of the present invention provides a material screening method for screening light-emitting layer materials of a light-emitting device, the material screening method comprising: configuring at least two material groups, each material group comprising a main material and a dye, at least one of the main material and the dye included in each two material groups being different from each other; using each material group as the light-emitting layer material to respectively prepare single-carrier devices; obtaining the defect energy between the main material and the dye in the single-carrier device corresponding to each material group; and screening a target material group from at least two material groups according to the defect energy corresponding to each material group, for use as the light-emitting layer material of the light-emitting device.

[0008] According to the aforementioned implementation of the second aspect of the present invention, using each material group as a light-emitting layer material to respectively fabricate a single-carrier device comprises: using each material group as a light-emitting layer material to respectively fabricate a single-hole device or a single-electron device.

[0009] According to any of the aforementioned embodiments of the second aspect of the present invention, the light-emitting device is a blue light-emitting device, and screening the target material group from at least two material groups according to the defect energy corresponding to each material group comprises: screening a material group having a defect energy less than or equal to 0.04 eV from at least two material groups as the target material group;

[0010] Alternatively, the light-emitting device is a red light-emitting device or a green light-emitting device, and the target material group is obtained by screening from at least two material groups according to the defect energy corresponding to each material group, including: screening a material group with a defect energy greater than or equal to 0.03eV from at least two material groups as the target material group; screening a material group with a defect energy between 0.03eV and 0.08eV from at least two material groups as the target material group.

[0011] According to any of the aforementioned embodiments of the second aspect of the present invention, using each material group as a light-emitting layer material to respectively fabricate a single-carrier device comprises: using each material group as a light-emitting layer material to respectively fabricate a single-hole device and a single-electron device;

[0012] Obtaining the defect energy between the main material and the dye in the single-carrier device corresponding to each material group includes: obtaining the first defect energy between the main material and the dye in the single-hole device corresponding to each material group; and obtaining the second defect energy between the main material and the dye in the single-electron device corresponding to each material group;

[0013] Screening the target material group from at least two material groups according to the defect energy corresponding to each material group includes: screening the target material group from at least two material groups according to the first defect energy and the second defect energy corresponding to each material group.

[0014] According to any of the aforementioned embodiments of the second aspect of the present invention, the light-emitting device is a blue light-emitting device, and screening the target material group from at least two material groups according to the first defect energy and the second defect energy corresponding to each material group comprises: screening the material group whose first defect energy and the second defect energy are both less than or equal to 0.04 eV from at least two material groups as the target material group; screening the target material group from at least two material groups according to the first defect energy and the second defect energy corresponding to each material group comprises: screening the material group whose first defect energy and the second defect energy are both less than or equal to 0.03 eV from at least two material groups as the target material group;

[0015] Alternatively, the light-emitting device is a red light-emitting device or a green light-emitting device, and the target material group is obtained by screening from at least two material groups according to the first defect energy and the second defect energy corresponding to each material group, including: screening from at least two material groups a material group in which the first defect energy and the second defect energy are both between 0.03eV and 0.08eV as the target material group.

[0016] According to any of the aforementioned embodiments of the second aspect of the present invention, the light-emitting device includes a stacked anode, a hole-assisted transport layer, a light-emitting layer, an electron-assisted transport layer and a cathode, and each material group is used as a light-emitting layer material to prepare a single carrier device, including: based on the light-emitting device, each material group is used as a light-emitting layer material, and the electron-assisted transport layer is replaced by an electron blocking layer to obtain a single hole device; and / or based on the light-emitting device, each material group is used as a light-emitting layer material, and the hole-assisted transport layer is replaced by a hole blocking layer to obtain a single electron device.

[0017] According to any of the aforementioned embodiments of the second aspect of the present invention, obtaining the defect energy between the main material and the dye in the single carrier device corresponding to each material group includes: detecting the current density of the single carrier device at a preset temperature and a preset voltage; and obtaining the defect energy according to the preset temperature, the preset voltage and the current density.

[0018] In a third aspect, an embodiment of the present invention provides a method for manufacturing a light-emitting device, comprising: obtaining a target material group according to the material screening method as described in any of the preceding items; and manufacturing a light-emitting device using the target material group as a light-emitting layer material.

[0019] In a fourth aspect, an embodiment of the present invention provides a display panel, comprising a light-emitting device as described above; the light-emitting device comprises a first light-emitting device and a second light-emitting device having different light-emitting colors from each other, wherein a turn-on voltage of the first light-emitting device is greater than a turn-on voltage of the second light-emitting device, and at least one of the first light-emitting device and the second light-emitting device is manufactured according to the manufacturing method of the light-emitting device as described above.

[0020] According to the aforementioned embodiment of the fourth aspect of the present invention, the first light emitting device is a blue light emitting device, and the second light emitting device is a red light emitting device or a green light emitting device.

[0021] The light-emitting device and its manufacturing method, material screening method, and display panel provided by the embodiments of the present invention can screen the light-emitting layer materials of the light-emitting device according to the defect energy, and can comprehensively consider the material interface between the main material of the light-emitting layer material and the dye, the bulk phase characteristics, and the energy that needs to be overcome for carrier injection. Compared with the traditional screening method using HOMO / LOMO, the material screening is more accurate and can effectively screen out material combinations that are suitable for the light-emitting layer of the light-emitting device and meet the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features and the accompanying drawings are not drawn to scale.

[0023] Figure 1 A flow chart showing a material screening method provided by an embodiment of the present invention;

[0024] Figure 2 A flow chart showing a material screening method provided by an embodiment of the present invention;

[0025] Figure 3 A flow chart showing a material screening method provided by another embodiment of the present invention;

[0026] Figure 4 A flow chart showing a material screening method provided by another embodiment of the present invention;

[0027] Figure 5 A flow chart of a method for manufacturing a light-emitting device provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0028] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0030] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "on" or "over" another layer or another region, it may mean that it is directly on the other layer or another region, or that other layers or regions are included between it and the other layer or another region. Moreover, if the component is turned over, the layer or a region will be "below" or "beneath" another layer or another region.

[0031] Organic Light-Emitting Diode (OLED) is an electroluminescent device based on organic materials. In full-color OLED displays, pixel crosstalk is prone to occur between red, green, and blue pixels. This problem mainly stems from the fact that the turn-on voltage of the blue light-emitting device is significantly higher than that of the green and red light, resulting in a lateral current between the red, green, and blue pixels when the blue light is turned on, causing the red and green pixels to also emit light when the blue light is turned on. The choice of different luminescent materials will affect the turn-on voltage of the luminescent device. Only by selecting the appropriate luminescent layer material can the turn-on voltage of the blue light-emitting device be reduced.

[0032] Based on the above problems, the embodiments of the present invention provide a light-emitting device and a manufacturing method thereof, a material screening method, and a display panel. The material screening method can screen out suitable light-emitting layer materials, thereby achieving the purpose of reducing the start-up voltage of the light-emitting device.

[0033] The light-emitting device provided in an embodiment of the present invention includes a light-emitting layer, which includes a main material and a dye doped in the main material; wherein when carriers are injected into the light-emitting layer, there is defect energy between the main material and the dye, and the defect energy satisfies a preset value range.

[0034] It should be noted that when the dye is doped in the host material, defects will be generated, and the defects have the ability to capture holes and electrons. In the present application, the defect energy is the energy required to overcome the defects when the carriers are injected into the light-emitting layer.

[0035] It should be noted that the present application does not impose any specific restrictions on the above-mentioned preset value range, which can be selected according to the type of light-emitting device.

[0036] According to the light-emitting device provided by the embodiment of the present invention, the material of the light-emitting layer is screened according to the defect energy, which can comprehensively consider the material interface between the main material of the light-emitting layer material and the dye, the bulk phase characteristics and the energy that needs to be overcome for carrier injection, etc. Compared with the traditional HOMO / LOMO screening method, the material screening is more accurate and can effectively screen out a material combination that is suitable for the light-emitting layer of the light-emitting device and meets the requirements, which is more conducive to achieving the purpose of reducing the start-up voltage and operating voltage of the light-emitting device.

[0037] In some optional embodiments, the light emitting device may be a blue light emitting device, the light emitting layer of the blue light emitting device includes a blue light host material and a blue light dye, and the above-mentioned preset value range may be no greater than 0.04 eV, that is, when carriers are injected into the light emitting layer, the defect energy between the blue light host material and the blue light dye may be less than or equal to 0.04 eV. The smaller the defect energy between the blue light host material and the blue light dye, the smaller the energy that needs to be overcome when the carriers are injected into the light emitting layer, so the above-mentioned design method can make the turn-on voltage and driving voltage of the blue light emitting device lower.

[0038] Optionally, when the light-emitting device is a blue light-emitting device, the above-mentioned preset value range can be no more than 0.03 eV, that is, when carriers are injected into the light-emitting layer, the defect energy between the blue light host material and the blue light dye can be less than or equal to 0.03 eV, which can further reduce the turn-on voltage of the blue light-emitting device.

[0039] In some optional embodiments, the light-emitting device may also be a red light-emitting device or a green light-emitting device, and the above-mentioned preset value range may be greater than or equal to 0.03 eV, that is, when carriers are injected into the light-emitting layer of the red light-emitting device or the green light-emitting device, the defect energy between the main material and the dye may be greater than or equal to 0.03 eV, which can improve the luminous efficiency of the green light-emitting device and the red light-emitting device in a high-brightness display state.

[0040] Optionally, when the light-emitting device is a red light-emitting device or a green light-emitting device, the above-mentioned preset value range can be 0.03eV to 0.08eV, that is, when carriers are injected into the light-emitting layer of the red light-emitting device or the green light-emitting device, the defect energy between the main material and the dye is between 0.03eV and 0.08eV, which can not only improve the luminous efficiency of the red light-emitting device and the green light-emitting device in the high-brightness display state, but also the operating voltage of the red light-emitting device and the green light-emitting device, thereby reducing the power consumption of the light-emitting device itself, thereby reducing the overall power consumption of the display panel.

[0041] In addition, an embodiment of the present invention further provides a display panel, comprising the light-emitting device as described above.

[0042] Since the light-emitting layer material of the light-emitting device is screened according to the defect energy, the start-up voltage and the operating voltage of the light-emitting device can be reduced, thereby reducing the power consumption of the light-emitting device itself, thereby reducing the overall power consumption of the display panel.

[0043] See also Figure 1 , Figure 1 A flow chart of a material screening method provided by an embodiment of the present invention is shown.

[0044] The material screening method provided in the embodiment of the present invention is used to screen the light-emitting layer material of the light-emitting device. The material screening method comprises:

[0045] Step S100: configuring at least two material groups, each material group including a main material and a dye, and at least one of the main material and the dye included in each two material groups is different from each other.

[0046] It is understandable that the light-emitting layer material of the light-emitting device generally includes a main material and a dye doped in the main material, the main material is used to maintain the layer structure and assume the carrier transport function, and the dye is used to generate emitting light and determine the luminescent color.

[0047] It should be noted that the present application does not impose any specific restrictions on the ratio and specific materials of the main material and dye selected for each material group; the main material of each material group can be selected from all existing materials that can be used as the main material of the light-emitting layer, and the dye of each material group can be selected from all existing materials that can be used as the dye of the light-emitting layer.

[0048] Step S200: using each material group as a light-emitting layer material to respectively manufacture single-carrier devices.

[0049] It can be understood that a single carrier device is a device that only allows one type of carrier to pass through.

[0050] Step S300: Obtaining defect energy between a host material and a dye in a single carrier device corresponding to each material group.

[0051] It should be noted that when the dye is doped in the host material, defects will be generated, and the defects have the ability to capture holes and electrons. In the present application, the defect energy is the energy required to overcome the defects when the carriers are injected into the light-emitting layer.

[0052] Step S400: Screening at least two material groups to obtain a target material group according to the defect energy corresponding to each material group, so as to be used as a light-emitting layer material of a light-emitting device.

[0053] In the prior art, the highest occupied energy level orbital HOMO / lowest occupied energy level orbital LOMO is generally used to screen the light-emitting layer materials, and the material screening error is large. The material screening method provided in the embodiment of the present invention screens the light-emitting layer materials of the light-emitting device according to the defect energy, and can comprehensively consider the material interface between the main material of the light-emitting layer material and the dye, the bulk phase characteristics, and the energy that needs to be overcome for carrier injection. Compared with the traditional screening method using HOMO / LOMO, the material screening is more accurate and can effectively screen out a material combination that is suitable for the light-emitting layer of the light-emitting device and meets the requirements.

[0054] Using the target material group screened out by the above method as the light-emitting layer material of the light-emitting device can optimize the energy transfer between the main material and the dye, reduce the potential barrier, and reduce the turn-on voltage and driving voltage of the light-emitting device; when manufacturing a display panel, using the target material group screened out by the above method as the light-emitting layer material of a light-emitting device with a relatively high turn-on voltage in the prior art can reduce the voltage difference between the light-emitting device and other light-emitting devices, thereby improving the pixel crosstalk problem during display of the display panel.

[0055] The material screening method provided in the embodiment of the present invention can be used to screen the light-emitting layer materials of the blue light-emitting device, so as to reduce the start-up voltage and driving voltage of the blue light-emitting device. In some optional embodiments, when configuring the material group, the blue light host material of each material group can be selected from anthracene organic compounds, such as ADN, MADN, TBADN, etc., and the blue light dye can be selected from boron nitrogen organic compounds, such as DABNA-1, DABNA-2, etc., and the ratio of the dye in the host can be in the range of 1% to 3%. Of course, the present application does not impose specific restrictions on the specific materials and ratios of the blue light host materials and dyes selected for each material group.

[0056] Of course, the material screening method provided in the embodiment of the present invention can also be used to screen the light-emitting layer materials of green light-emitting devices and red light-emitting devices, which can reduce the operating voltage of green light-emitting devices and red light-emitting devices, and then reduce the power consumption of the light-emitting devices themselves, thereby reducing the overall power consumption of the display panel, and at the same time can also improve the luminous efficiency of green light-emitting devices and red light-emitting devices in the high-brightness display state.

[0057] It is understandable that the material screening method provided in the embodiment of the present invention can be based on the light-emitting device and use each material group as the light-emitting layer material when manufacturing a single carrier device.

[0058] In some optional embodiments, the light-emitting device may include a stacked anode, a hole-assisted transport layer, a light-emitting layer, an electron-assisted transport layer, and a cathode. The anode is used to generate holes, the hole-assisted transport layer is used to assist the holes to be transported to the light-emitting layer, the cathode is used to generate electrons, the electron-assisted transport layer is used to assist the electrons to be transported to the light-emitting layer, and the holes and electrons are recombined in the light-emitting layer to emit light.

[0059] Optionally, the hole-assisting transport layer may include a hole injection layer and a hole transport layer, wherein the hole injection layer and the hole transport layer are stacked between the anode and the light-emitting layer, and the electron-assisting transport layer may include an electron injection layer and an electron transport layer, wherein the electron injection layer and the electron transport layer are stacked between the cathode and the light-emitting layer.

[0060] It can be understood that the single-carrier device can be a single-hole device or a single-electron device. The single-hole device only allows holes to pass through, while the single-electron device only allows electrons to pass through.

[0061] Optionally, when manufacturing a single hole device, a light-emitting device can be used as a basis, each material group can be used as a light-emitting layer material, and the electron auxiliary transport layer can be replaced by an electron blocking layer to obtain a single hole device.

[0062] Optionally, when making a single electron device, a light-emitting device can be used as a basis, each material group can be used as a light-emitting layer material, and the hole auxiliary transport layer can be replaced by a hole blocking layer to obtain a single electron device.

[0063] It is understood that a single-hole device may include a stacked anode, a hole-assisted transport layer, a light-emitting layer, an electron blocking layer and a cathode, and a single-electron device may include a stacked anode, a hole blocking layer, a light-emitting layer, an electron-assisted transport layer and a cathode. In a single-hole device, the electron-assisted transport layer is replaced with an electron blocking layer, which can prevent electrons generated by the cathode from entering the light-emitting layer, thereby achieving the purpose of allowing only hole transport; in a single-electron device, the hole-assisted transport layer is replaced with a hole blocking layer, which can prevent holes generated by the anode from entering the light-emitting layer, thereby achieving the purpose of allowing only electron transport.

[0064] Optionally, when making a single-electron device, the hole blocking layer can be replaced by an electron injection layer that has a hole blocking function. When making a single-hole device, the electron blocking layer can be replaced by a hole injection layer that has an electron blocking function, which is also within the protection scope of the present invention.

[0065] In some optional embodiments, in the material screening method provided by the embodiments of the present invention, in the single carrier device corresponding to each material group, the defect energy between the main material and the dye can be calculated according to the following formula:

[0066] Et=mkT Formula 1

[0067] m=logJ / logV Formula 2

[0068] Wherein, Et is the defect energy, T is the preset temperature, V is the preset voltage loaded on the single carrier device, J is the current density of the single carrier device under the conditions of preset temperature T and preset voltage V, and k is the Boltzmann constant.

[0069] Optionally, step S300 may include:

[0070] Detecting the current density of a single-carrier device at a preset temperature and a preset voltage;

[0071] The defect energy is obtained according to the preset temperature, the preset voltage and the current density.

[0072] In some optional embodiments, the material screening method provided by the embodiments of the present invention can screen the target material group only based on the defect energy between the main material and the dye in the single-hole device or single-electron device corresponding to each material group, thereby increasing the freedom of selection of the light-emitting layer material.

[0073] See also Figure 2 , Figure 2 A flow chart of a material screening method provided by an embodiment of the present invention is shown.

[0074] In some optional embodiments, the material screening method provided by the embodiment of the present invention can screen the target material group according to the defect energy between the host material and the dye in the single hole device corresponding to each material group. Then,

[0075] Step S200 may include: S201: using each material group as a light-emitting layer material to respectively manufacture single-hole devices.

[0076] Step S300 may include: S301: obtaining a first defect energy Et1 between a host material and a dye in a single hole device corresponding to each material group.

[0077] Step S400 includes: S401: screening a target material group from at least two material groups according to a first defect energy Et1 corresponding to each material group.

[0078] The material screening method provided in the embodiment of the present invention can be used to screen the light-emitting layer material of a blue light-emitting device. In some optional embodiments, when the light-emitting device is a blue light-emitting device, step S400 may include: screening a material group with a first defect energy Et1 less than or equal to 0.04 eV from at least two material groups as a target material group.

[0079] In the single-hole device corresponding to the material group, the smaller the first defect energy Et1 between the main material and the dye, the smaller the energy that needs to be overcome for hole injection when the corresponding light-emitting device is powered on. Therefore, the above design method can make the blue light-emitting device made using the target material group as the light-emitting layer material have a lower turn-on voltage and driving voltage.

[0080] Optionally, a material group having a first defect energy Et1 less than or equal to 0.03 eV may be selected from at least two material groups as a target material group, which can further reduce the turn-on voltage of the blue light emitting device.

[0081] In order to verify the actual effect of the above design, the following experimental examples and comparative examples are designed: in the experimental examples, the first defect energy Et1 corresponding to the material group is less than 0.03 eV, and in the comparative example, the first defect energy Et1 corresponding to the material group is greater than 0.03 eV. The performance test results of the blue light emitting devices corresponding to the comparative example and the experimental example are shown in Table 1 below. In Table 1 below, BD is a blue light dye, and BH1 and BH2 are two different blue light host materials.

[0082] It can be seen from the following Table 1 that the blue light emitting devices corresponding to the experimental example and the comparative example only differ in the main material of the light emitting layer. Compared with the comparative example, the turn-on voltage of the blue light emitting device corresponding to the experimental example is reduced by 0.30 V, and the driving voltage is reduced by 0.55 V. It can be seen from the above performance test results that the technical solution adopted by the present invention can significantly reduce the turn-on voltage and driving voltage of the blue light emitting device, thereby improving the pixel crosstalk problem during display of the display panel.

[0083] Table 1 Performance test comparison table of blue light emitting devices corresponding to comparative examples and experimental examples

[0084]

[0085] The material screening method provided in the embodiment of the present invention can also be used to screen the light-emitting layer materials of red light-emitting devices or green light-emitting devices. In some optional embodiments, when the light-emitting device is a red light-emitting device or a green light-emitting device, step S400 may include: screening a material group with a first defect energy Et1 greater than or equal to 0.03 eV from at least two material groups as a target material group. The above design method can improve the luminous efficiency of green light-emitting devices and red light-emitting devices in a highlighted display state.

[0086] Optionally, a material group with a first defect energy Et1 between 0.03eV and 0.08eV can be screened from at least two material groups as a target material group, which can not only improve the luminous efficiency of red light emitting devices and green light emitting devices in a high-brightness display state, but also reduce the operating voltage of the red light emitting devices and green light emitting devices, thereby reducing the power consumption of the light emitting devices themselves, thereby reducing the overall power consumption of the display panel.

[0087] See also Figure 3 , Figure 3 A flow chart showing a material screening method provided by another embodiment of the present invention.

[0088] In some optional embodiments, the material screening method provided by the embodiment of the present invention can also screen the target material group according to the defect energy between the main material and the dye in the single electron device corresponding to each material group. Then,

[0089] Step S200 may include: S202: using each material group as a light-emitting layer material to respectively manufacture a single electron device.

[0090] Step S300 may include: S302: obtaining a second defect energy Et2 between a main material and a dye in a single electron device corresponding to each material group.

[0091] Step S400 includes: S402: screening a target material group from at least two material groups according to a second defect energy Et2 corresponding to each material group.

[0092] The material screening method provided in the embodiment of the present invention can be used to screen the light-emitting layer material of a blue light-emitting device. In some optional embodiments, when the light-emitting device is a blue light-emitting device, step S400 may include: screening a material group with a second defect energy Et2 less than or equal to 0.04 eV from at least two material groups as a target material group.

[0093] In the single-electron device corresponding to the material group, the smaller the first defect energy Et1 between the main material and the dye, the smaller the energy that needs to be overcome for electron injection when the corresponding light-emitting device is powered on. Therefore, the above design method can make the blue light-emitting device made using the target material group as the light-emitting layer material have a lower turn-on voltage and driving voltage.

[0094] Optionally, a material group having a second defect energy Et2 less than or equal to 0.03 eV can be selected from at least two material groups as a target material group, which can further reduce the turn-on voltage of the blue light emitting device.

[0095] In order to verify the actual effect of the above design, the following experimental examples and comparative examples were designed: in the experimental examples, the second defect energy Et2 corresponding to the material group is less than 0.03 eV, and in the comparative example, the second defect energy Et2 corresponding to the material group is greater than 0.03 eV. The performance test results of the blue light emitting devices corresponding to the comparative example and the experimental example are shown in Table 2 below.

[0096] Table 2 Performance test comparison table of blue light emitting devices corresponding to comparative examples and experimental examples

[0097]

[0098] In the above Table 2, BD is a blue light dye, and BH1 and BH3 are two different blue light host materials.

[0099] It can be seen from Table 2 above that the blue light emitting devices corresponding to the experimental example and the comparative example only differ in the main material of the light emitting layer. Compared with the comparative example, the turn-on voltage of the blue light emitting device corresponding to the experimental example is reduced by 0.28V, and the driving voltage is reduced by 0.46V. It can be seen from the above performance test results that the technical solution adopted by the present invention can significantly reduce the turn-on voltage and driving voltage of the blue light emitting device, thereby improving the pixel crosstalk problem during display of the display panel.

[0100] The material screening method provided in the embodiment of the present invention can also be used to screen the light-emitting layer materials of red light-emitting devices or green light-emitting devices. In some optional embodiments, when the light-emitting device is a red light-emitting device or a green light-emitting device, step S400 may include: screening a material group with a second defect energy Et2 greater than or equal to 0.03 eV from at least two material groups as a target material group. The above design method can improve the luminous efficiency of green light-emitting devices and red light-emitting devices in a highlighted display state.

[0101] Optionally, a material group with a second defect energy Et1 between 0.03eV and 0.08eV can be screened from at least two material groups as a target material group, which can not only improve the luminous efficiency of red light emitting devices and green light emitting devices in a high-brightness display state, but also reduce the operating voltage of the red light emitting devices and green light emitting devices, thereby reducing the power consumption of the light emitting devices themselves, thereby reducing the overall power consumption of the display panel.

[0102] See also Figure 4 , Figure 4 A flow chart showing a material screening method provided by yet another embodiment of the present invention.

[0103] In some optional embodiments, the material screening method provided by the embodiment of the present invention can also screen the target material group according to the defect energy between the main material and the dye in the single hole device and the single electron device corresponding to each material group. Then,

[0104] Step S200 may include: S203: using each material group as a light-emitting layer material to respectively manufacture a single-hole device and a single-electron device.

[0105] Optionally, step S203 may include:

[0106] Based on the light-emitting device, each material group is used as the light-emitting layer material, and the electron auxiliary transport layer is replaced by an electron blocking layer to obtain a single hole device; and

[0107] Based on the light-emitting device, each material group is used as the light-emitting layer material, and the hole-assisting transport layer is replaced by a hole-blocking layer to obtain a single-electron device.

[0108] Step S300 may include: S303: obtaining a first defect energy Et1 between a host material and a dye in a single hole device corresponding to each material group; and

[0109] The second defect energy Et2 between the main material and the dye in the single electron device corresponding to each material group is obtained.

[0110] Step S400 includes: S403: screening a target material group from at least two material groups according to a first defect energy Et1 and a second defect energy Et2 corresponding to each material group.

[0111] At the same time, the light-emitting layer materials of the light-emitting device are screened according to the first defect energy Et1 and the second defect energy Et2 corresponding to each material group, which can comprehensively consider the energy that needs to be overcome for hole and electron injection. The screening standard is more stringent, and the target material group screened by this standard is used for the light-emitting layer materials of the light-emitting device, which can further reduce the start-up voltage and driving voltage of the light-emitting device.

[0112] The material screening method provided in the embodiment of the present invention can be used to screen the light-emitting layer material of a blue light-emitting device. In some optional embodiments, when the light-emitting device is a blue light-emitting device, step S403 may include: screening a material group whose first defect energy Et1 and second defect energy Et2 are both less than or equal to 0.04 eV from at least two material groups as a target material group.

[0113] In the single-hole device and single-electron device corresponding to the material group, the smaller the first defect energy Et1 and the second defect energy Et2 between the main material and the dye, the smaller the energy that needs to be overcome for hole and electron injection when the corresponding light-emitting device is powered on. Therefore, the above design method can make the blue light-emitting device made using the target material group as the light-emitting layer material have a lower turn-on voltage and driving voltage.

[0114] Optionally, a material group in which the first defect energy Et1 and the second defect energy Et2 are both less than or equal to 0.03 eV can be selected from at least two material groups as a target material group, which can further reduce the turn-on voltage of the blue light emitting device.

[0115] In order to verify the practical effect of the above design, the following experimental examples and comparative examples were designed:

[0116] Table 3 Performance test comparison table of blue light emitting devices corresponding to comparative examples and experimental examples

[0117]

[0118] In the experimental example, the first defect energy Et1 and the second defect energy Et2 corresponding to the material group are both less than 0.03 eV, and in the comparative example, the first defect energy Et1 and the second defect energy Et2 corresponding to the material group are both greater than 0.03 eV. The performance test results of the blue light emitting devices corresponding to the comparative example and the experimental example are shown in Table 3 above. Among them, BD is a blue light dye, and BH4 and BH5 are two different blue light host materials.

[0119] It can be seen from Table 3 above that the blue light emitting devices corresponding to the experimental example and the comparative example differ only in the main material of the light emitting layer. Compared with the comparative example, the turn-on voltage of the blue light emitting device corresponding to the experimental example is reduced by 0.32 V, and the driving voltage is reduced by 0.51 V. It can be seen from the above performance test results that the technical solution adopted by the present invention can significantly reduce the turn-on voltage and driving voltage of the blue light emitting device, thereby improving the pixel crosstalk problem during display of the display panel.

[0120] The material screening method provided in the embodiment of the present invention can also be used to screen the light-emitting layer materials of red light-emitting devices or green light-emitting devices. In some optional embodiments, when the light-emitting device is a red light-emitting device or a green light-emitting device, step S403 may include: screening a material group whose first defect energy Et1 and second defect energy Et2 are both greater than or equal to 0.03 eV from at least two material groups as a target material group; the above design method can further improve the luminous efficiency of green light-emitting devices and red light-emitting devices in a highlighted display state.

[0121] Optionally, a material group with a first defect energy Et1 and a second defect energy Et2 between 0.03eV and 0.08eV can be screened from at least two material groups as a target material group, which can not only improve the luminous efficiency of red light emitting devices and green light emitting devices in a high-brightness display state, but also reduce the operating voltage of the red light emitting devices and green light emitting devices, thereby reducing the power consumption of the light emitting devices themselves, thereby reducing the overall power consumption of the display panel.

[0122] In order to verify the effect of improving the luminous efficiency of the light-emitting device in the high-brightness display state, the following experimental examples and comparative examples are designed. Both the experimental examples and comparative examples are red light-emitting devices. In the comparative example, the defect energy corresponding to the material group is less than 0.03eV, and in the experimental example, the defect energy corresponding to the material group is between 0.03eV and 0.08eV. The performance test results of the red light-emitting devices corresponding to the comparative example and the experimental example are shown in Table 4 below.

[0123] Table 4 Performance test comparison table of red light emitting devices corresponding to comparative examples and experimental examples

[0124] Defect energy Et L(nits) Vd(V) Eff.(cd / A) Comparative Example Et<0.03eV 6000 <![CDATA[Vd0]]> 100％ Experimental example 0.03eV <Et<0.08eV 6000 <![CDATA[Vd0-0.03V]]> 110.2％

[0125] Wherein, L is the luminance of the red light emitting device, nits is the unit of luminance, Vd represents the operating voltage of the light emitting device, and Eff. represents the luminous efficiency of the light emitting device.

[0126] It can be seen from Table 4 above that in the tests of the experimental example and the comparative example, the red light emitting device is in a high-brightness display state with a brightness of 6000 nits; taking the operating voltage of the red light emitting device in the comparative example as the reference voltage value Vd0, the operating voltage of the red light emitting device in the experimental example is reduced by 0.03V, so that the power consumption of the red light emitting device in the experimental example is lower than that in the comparative example; at the same time, compared with the comparative example, the luminous efficiency of the red light emitting device in the experimental example is improved by 10.2%.

[0127] It can be seen from the above performance test results that the technical solution adopted by the present invention can improve the luminous efficiency of the red or green light emitting device in the high-brightness display state, and at the same time can reduce the operating voltage of the red or green light emitting device, thereby reducing the power consumption of the light emitting device.

[0128] See also Figure 5 , Figure 5 A flow chart of a method for manufacturing a light-emitting device provided by an embodiment of the present invention is shown.

[0129] In addition, an embodiment of the present invention further provides a method for manufacturing a light-emitting device, which can use the material screening method described above to screen the light-emitting layer material. The method for manufacturing the light-emitting device includes:

[0130] Step S10: obtaining a target material group according to the material screening method as described above;

[0131] Step S20: using the target material group as the light-emitting layer material to manufacture a light-emitting device.

[0132] According to the method for manufacturing a light-emitting device provided in an embodiment of the present invention, a target material group including a main material and a dye is screened according to defect energy, and the target material group is used as the light-emitting layer material of the light-emitting device to manufacture the light-emitting device. Compared with the prior art, the light-emitting device has a lower start-up voltage and a lower driving voltage.

[0133] In addition, an embodiment of the present invention also provides a display panel, comprising a first light-emitting device and a second light-emitting device having different luminous colors, wherein a turn-on voltage of the first light-emitting device is greater than a turn-on voltage of the second light-emitting device, and at least one of the first light-emitting device and the second light-emitting device can be manufactured according to the manufacturing method of the light-emitting device as described above.

[0134] The display panel provided by the embodiment of the present invention can screen the light-emitting layer material of the first light-emitting device according to the defect energy, and use the screened target material group as the light-emitting layer material to manufacture the first light-emitting device, which can reduce the start-up voltage and driving voltage of the first light-emitting device, and reduce the voltage difference between the first light-emitting device and the second light-emitting device when the display panel is displayed, thereby improving the pixel crosstalk problem when the display panel is displayed.

[0135] In addition, the display panel provided by the embodiment of the present invention can screen the light-emitting layer materials of the first light-emitting device and the second light-emitting device according to the defect energy, and use the screened target material group as the light-emitting layer material to manufacture the first light-emitting device and the second light-emitting device, which can reduce the driving voltage of the first light-emitting device and the second light-emitting device. The reduction in power consumption of the light-emitting device further reduces the overall power consumption of the display panel.

[0136] It can be understood that the first light emitting device may be a blue light emitting device, and the second light emitting device may be a red light emitting device or a green light emitting device.

[0137] In some optional embodiments, the display panel provided by the embodiments of the present invention may include a blue light emitting device, a red light emitting device and a green light emitting device. The turn-on voltage of the blue light emitting device is greater than that of the red light emitting device and the green light emitting device. The blue light emitting device can be manufactured according to the manufacturing method of the light emitting device as described above.

[0138] By screening a material group of a blue main material and a blue dye according to defect energy, and using the screened material group as a light-emitting layer material to make a blue light-emitting device, the start-up voltage and the driving voltage of the blue light-emitting device can be reduced, and the voltage difference between the blue light-emitting device and the red light-emitting device and the green light-emitting device can be reduced, thereby improving the pixel crosstalk problem between the red, green and blue pixels when the display panel is displayed.

[0139] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A light emitting device, characterized in that: include: A light-emitting layer, comprising a host material and a dye doped in the host material; Among them, when carriers are injected into the light-emitting layer, there is defect energy between the main material and the dye, and the defect energy satisfies a preset value range; the light-emitting device includes a blue light-emitting device, and the defect energy is less than or equal to 0.04eV; the light-emitting device also includes a red light-emitting device or a green light-emitting device, and the defect energy is greater than or equal to 0.03eV.

2. The light emitting device according to claim 1, characterized in that: The defect energy of the blue light emitting device is less than or equal to 0.03 eV.

3. The light emitting device according to claim 1, characterized in that: The defect energy of the red light emitting device or the green light emitting device is between 0.03 eV and 0.08 eV.

4. A material screening method for screening light-emitting layer materials of a light-emitting device, characterized in that: include: configuring at least two material groups, each of the material groups comprising a main material and a dye, and at least one of the main material and the dye included in each two material groups is different from each other; Using each of the material groups as the light-emitting layer material, respectively fabricating single-carrier devices; Obtaining defect energy between the host material and the dye in the single carrier device corresponding to each group of the material groups; According to the defect energy corresponding to each material group, a target material group is obtained by screening from the at least two material groups for use as a light-emitting layer material of a light-emitting device, wherein the light-emitting device is a blue light-emitting device, and the material group whose defect energy is less than or equal to 0.04 eV is screened from the at least two material groups as the target material group.

5. The material screening method according to claim 4, characterized in that: The method of using each of the material groups as the light-emitting layer material to respectively manufacture single-carrier devices includes: using each of the material groups as the light-emitting layer material to respectively manufacture single-hole devices or single-electron devices.

6. The material screening method according to claim 5, characterized in that: The light emitting device is a red light emitting device or a green light emitting device, and the step of screening the target material group from the at least two material groups according to the defect energy corresponding to each material group comprises: The material group having the defect energy greater than or equal to 0.03 eV is selected from the at least two material groups as the target material group.

7. The material screening method according to claim 6, characterized in that: The material group having the defect energy between 0.03 eV and 0.08 eV is selected from the at least two material groups as the target material group.

8. The material screening method according to claim 4, characterized in that: The method of using each of the material groups as the light-emitting layer material to respectively manufacture single-carrier devices comprises: Using each of the material groups as the light-emitting layer material, a single hole device and a single electron device are respectively manufactured; The obtaining of defect energy between the host material and the dye in the single carrier device corresponding to each material group comprises: Obtaining a first defect energy between the host material and the dye in the single hole device corresponding to each group of the material groups; and Obtaining a second defect energy between the host material and the dye in the single electron device corresponding to each group of the material groups; The step of screening the target material group from the at least two material groups according to the defect energy corresponding to each material group comprises: A target material group is obtained by screening the at least two material groups according to the first defect energy and the second defect energy corresponding to each material group.

9. The material screening method according to claim 8, characterized in that: The light emitting device is a blue light emitting device, and the target material group is obtained by screening from the at least two material groups according to the first defect energy and the second defect energy corresponding to each material group, comprising: Selecting the material group whose first defect energy and the second defect energy are both less than or equal to 0.04 eV from the at least two material groups as the target material group; Alternatively, the light-emitting device is a red light-emitting device or a green light-emitting device, and the step of screening the target material group from the at least two material groups according to the first defect energy and the second defect energy corresponding to each material group comprises: The material group in which both the first defect energy and the second defect energy are between 0.03 eV and 0.08 eV is selected from the at least two material groups as the target material group.

10. The material screening method according to claim 9, characterized in that: The light emitting device is a blue light emitting device, and the target material group is obtained by screening from the at least two material groups according to the first defect energy and the second defect energy corresponding to each material group, comprising: The material group in which both the first defect energy and the second defect energy are less than or equal to 0.03 eV is selected from the at least two material groups as the target material group.

11. The material screening method according to claim 4, characterized in that: The light-emitting device comprises a stacked anode, a hole auxiliary transport layer, a light-emitting layer, an electron auxiliary transport layer and a cathode, and the single-carrier devices are prepared by using each group of the material groups as the light-emitting layer material, respectively, including: Based on the light-emitting device, each group of the material groups is used as the light-emitting layer material, and the electron auxiliary transport layer is replaced by an electron blocking layer to obtain a single hole device; and / or Based on the light-emitting device, each group of the material groups is used as the light-emitting layer material, and the hole auxiliary transport layer is replaced by a hole blocking layer to obtain a single electron device.

12. A method for manufacturing a light emitting device, characterized in that: include: Obtaining a target material group according to the material screening method according to any one of claims 4 to 11; The target material group is used as the light-emitting layer material to manufacture a light-emitting device.

13. A display panel, characterized in that: It comprises a light-emitting device as described in any one of claims 1 to 3; the light-emitting device comprises a first light-emitting device and a second light-emitting device having different light-emitting colors from each other, wherein a start-up voltage of the first light-emitting device is greater than a start-up voltage of the second light-emitting device, and at least one of the first light-emitting device and the second light-emitting device is manufactured according to the method for manufacturing a light-emitting device according to claim 12.

14. The display panel according to claim 13, characterized in that: The first light emitting device is a blue light emitting device, and the second light emitting device is a red light emitting device or a green light emitting device.

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