Design method of light emitting device, light emitting device and display device

Abstract

The present application discloses a design method of a light-emitting device, a light-emitting device and a display device. The design method of the light-emitting device includes: obtaining the capacitance of a first device, wherein the first device is one of a first light-emitting device formed by the first light-emitting color portion and the common layer, a second light-emitting device formed by the second light-emitting color portion and the common layer, and a third light-emitting device formed by the third light-emitting color portion and the common layer; based on the capacitance of the first device, adjusting the capacitance of the second device so that the capacitance difference between the capacitance of the second device and the capacitance of the first device is less than a preset value, wherein the preset value is greater than or equal to 0 and less than 1.5*10 ‑9 F, the second device is the other two of the first light emitting device, the second light emitting device and the third light emitting device. The embodiment of the present application can improve the display defects such as tailing and heterochromaticity of the light emitting device and enhance the display effect of the light emitting device.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a design method for a light-emitting device, a light-emitting device and a display apparatus. Background Art

[0002] Organic light-emitting diodes (OLEDs) are widely used in new display devices such as mobile phones and tablets due to their advantages such as self-luminescence, wide color gamut, and wide viewing angle. However, during the display process, organic light-emitting diodes usually have poor display effects in the first frame or even the first few frames, such as differences in brightness in the first frame, and display problems such as tailing and heterochromatic colors, which in turn affect the display effect. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a design method for a light-emitting device, a light-emitting device and a display device, which can significantly reduce the capacitance difference between the first light-emitting device, the second light-emitting device and the third light-emitting device, and reduce the first-frame brightness difference of the light-emitting device caused by the difference in capacitance between the device structures, thereby improving the display defects such as AMOLD tailing and color heterogeneity of the light-emitting device, and enhancing the display effect of the light-emitting device.

[0004] In a first aspect, an embodiment of the present application provides a design method for a light-emitting device, wherein the light-emitting device includes a substrate, a common layer and a light-emitting layer, wherein the common layer includes an anode, a hole transport layer, a hole blocking layer, an electron transport layer, a cathode and a light extraction layer sequentially arranged in a direction away from the substrate, wherein the light-emitting layer is located between the hole transport layer and the hole blocking layer, wherein the light-emitting layer includes a first light-emitting color portion, a second light-emitting color portion and a third light-emitting color portion, wherein the first light-emitting color portion includes a first color light-emitting layer and a first light-emitting color auxiliary layer, wherein the second light-emitting color portion includes a second color light-emitting layer and a second light-emitting color auxiliary layer, and wherein the third light-emitting color portion includes a third color light-emitting layer and a third light-emitting color auxiliary layer, wherein the method includes:

[0005] Obtaining a capacitance of a first device, the first device being one of a first light-emitting device formed by the first light-emitting color portion and the common layer, a second light-emitting device formed by the second light-emitting color portion and the common layer, and a third light-emitting device formed by the third light-emitting color portion and the common layer;

[0006] Based on the capacitance of the first device, the capacitance of the second device is adjusted so that the capacitance difference between the capacitance of the second device and the capacitance of the first device is less than a preset value, wherein the preset value is greater than or equal to 0 and less than 1.5*10 - 9 F, the second device is the other two of the first light-emitting device, the second light-emitting device and the third light-emitting device.

[0007] In some examples, adjusting the capacitance of the second device based on the capacitance of the first device so that a capacitance difference between the capacitance of the second device and the capacitance of the first device is less than a preset value includes:

[0008] Based on the capacitance of the first device, material mobility and / or energy level of the second device is adjusted to change the capacitance of the second device.

[0009] In some examples, the material mobility of the second device is achieved by at least one of the following methods:

[0010] Adjust the relative substitution positions of substituents;

[0011] Changing the number of units with push-electron characteristics;

[0012] Adjust the planarity of the molecule;

[0013] Extend the π conjugation length.

[0014] In some examples, the energy level of the second device is achieved by at least one of the following methods:

[0015] changing the energy of the highest occupied molecular orbital and / or the lowest unoccupied molecular orbital;

[0016] Vary the length of the conjugated chain.

[0017] In some examples, the first device is the third light emitting device, the second device is the first light emitting device and the second light emitting device,

[0018] The first light emitting device satisfies:

[0019] The difference between the absolute value of the highest occupied molecular orbital of the first luminescent color auxiliary layer and the absolute value of the highest occupied molecular orbital of the hole transport layer is greater than a first preset energy value and less than a second preset energy value;

[0020] The difference between the absolute value of the highest occupied molecular orbital of the first color light-emitting layer and the absolute value of the highest occupied molecular orbital of the first light-emitting color auxiliary layer is greater than the third preset energy value and less than the fourth preset energy value;

[0021] The ratio of the material mobility between the hole transport layer and the first light-emitting color auxiliary layer is greater than a first preset mobility and less than a second preset mobility;

[0022] A ratio of material mobility between the first light-emitting color auxiliary layer and the first color light-emitting layer is greater than a third preset mobility and less than a fourth preset mobility.

[0023] In some examples, the second light emitting device satisfies:

[0024] The difference between the absolute value of the highest occupied molecular orbital of the second luminescent color auxiliary layer and the absolute value of the highest occupied molecular orbital of the hole transport layer is less than a fifth preset energy value;

[0025] The difference between the absolute value of the highest occupied molecular orbital of the second color light-emitting layer and the absolute value of the highest occupied molecular orbital of the second color light-emitting auxiliary layer is less than a sixth preset energy value;

[0026] The material mobility of the hole transport layer is greater than the material mobility between the second light-emitting color auxiliary layers;

[0027] The material mobility of the second light-emitting color auxiliary layer is greater than the material mobility of the green light-emitting layer.

[0028] In some examples, the material of the hole transport layer is a mixed material, and adjusting the material mobility and / or energy level of the second device includes:

[0029] The proportion of the mixed material in the material of the hole transport layer is adjusted to change the material mobility and / or energy level of the second device.

[0030] In a second aspect, an embodiment of the present application provides a light emitting device, including:

[0031] substrate substrate;

[0032] A common layer, the common layer comprising an anode, a hole transport layer, a hole blocking layer, an electron transport layer, a cathode and a light extraction layer arranged in sequence in a direction away from the substrate;

[0033] a light-emitting layer, the light-emitting layer being located between the hole transport layer and the hole blocking layer, the light-emitting layer comprising a first light-emitting color portion, a second light-emitting color portion and a third light-emitting color portion,

[0034] The capacitance difference between the first light-emitting device formed by the first light-emitting color portion and the common layer, the second light-emitting device formed by the second light-emitting color portion and the common layer, and the third light-emitting device formed by the third light-emitting color portion and the common layer is less than a preset value, and the preset value is greater than or equal to 0 and less than 1.5*10 -9 F.

[0035] In some examples, the first light emitting device is a blue light emitting device, and the second light emitting device is a green light emitting device, wherein

[0036] The blue light device meets the following requirements:

[0037] 0.15ev<|HOMOBPrime |-|HOMO HT |<0.3ev,

[0038] 0.2ev<|HOMO BH |-|HOMO BPrime |<0.4ev;

[0039] The green light device meets the following requirements:

[0040] |HOMO GPrime |-|HOMO HT |<0.15ev,

[0041] |HOMO GH |-|HOMO GPrime |<0.15ev;

[0042] Wherein, the HOMO BPrime is the highest occupied molecular orbital of the blue light auxiliary layer of the blue light device, the HOMO HT is the highest occupied molecular orbital of the hole transport layer, the HOMO BH is the highest occupied molecular orbital of the blue light emitting layer of the blue light device, the HOMO GPrime is the highest occupied molecular orbital of the green light auxiliary layer of the green light device, the HOMO GH It is the highest occupied molecular orbital of the green light-emitting layer of the green light-emitting device.

[0043] In some examples, the absolute value of the difference between the highest occupied molecular orbital of the blue light auxiliary layer and the hole transport layer is 0.16, the absolute value of the difference between the highest occupied molecular orbital of the blue light-emitting layer and the blue light auxiliary layer is 0.31, the absolute value of the difference between the highest occupied molecular orbital of the green light auxiliary layer and the hole transport layer is 0.18, and the absolute value of the difference between the highest occupied molecular orbital of the green light-emitting layer and the green light auxiliary layer is 0.06.

[0044] In some examples,

[0045] The blue light device meets the following requirements:

[0046] 100 <Mobility(HTL) / Mobility(BPrime)<1000,

[0047] 1000 <Mobility(BPrime) / Mobility(BH)<100000;

[0048] The green light device meets the following requirements:

[0049] Mobility(HTL)>Mobility(GPrime),

[0050] Mobility(GPrime)>Mobility(GH);

[0051] Among them, the Mobility (HTL) is the material mobility of the hole transport layer, the Mobility (BPrime) is the material mobility of the blue light auxiliary layer, the Mobility (BH) is the material mobility of the blue light-emitting layer, the Mobility (GPrime) is the material mobility of the green light auxiliary layer, and the Mobility (GH) is the material mobility of the green light-emitting layer.

[0052] In some examples, the ratio of material mobility between the hole transport layer and the blue light auxiliary layer is 159, the ratio of material mobility between the blue light auxiliary layer and the blue light-emitting layer is 18000, the ratio of material mobility between the hole transport layer and the green light auxiliary layer is 24, and the ratio of material mobility between the green light auxiliary layer and the green light-emitting layer is 32.

[0053] In some examples, the capacitance of the first light emitting device, the second light emitting device, and the third light emitting device is changed by adjusting material mobility and / or energy levels.

[0054] In a third aspect, an embodiment of the present application provides a display device, comprising a light-emitting device according to the second aspect.

[0055] The design method of the light-emitting device, the light-emitting device and the display device provided in the embodiments of the present application adjust the capacitance of the first light-emitting device, the second light-emitting device and the third light-emitting device so that the capacitance of the first light-emitting device, the second light-emitting device and the third light-emitting device are at the same level, thereby reducing the brightness difference of the first frame of the device caused by the difference in capacitance between the device structures, that is, by limiting the physical properties of the functional layer material of the light-emitting device, the capacitance difference between the first light-emitting device, the second light-emitting device and the third light-emitting device can be greatly reduced, and the brightness difference of the first frame of the light-emitting device caused by the difference in capacitance between the device structures is reduced, thereby improving the display poor phenomenon of the light-emitting device such as AMOLD tailing and heterochromaticity, and enhancing the display effect of the light-emitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0057] Figure 1A Nyquist spectrum of an impedance spectrum of a conventional OLED and a schematic diagram of its corresponding equivalent circuit;

[0058] Figure 2 It is a schematic diagram of a typical 2T1CP metal oxide semiconductor field effect transistor (PMOS) driving circuit;

[0059] Figure 3 A schematic diagram of the process of OLED being driven to emit light;

[0060] Figure 4 Schematic diagram of the change of capacitance of an organic electroluminescent device with voltage;

[0061] Figure 5 A schematic diagram of the process by which the interaction of various layers of materials in a light-emitting device affects the capacitance of the device;

[0062] Figure 6 is a schematic structural diagram of a light emitting device according to an embodiment of the present invention;

[0063] Figure 7 is a flow chart of a method for designing a light emitting device according to an embodiment of the present invention;

[0064] Figure 8 It is a schematic diagram comparing the capacitance of the light emitting device of the reference example and the light emitting device of the present invention. DETAILED DESCRIPTION

[0065] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant disclosure, rather than to limit the disclosure. It should also be noted that, for ease of description, only the parts related to the disclosure are shown in the accompanying drawings.

[0066] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0067] The following describes a design method of a light emitting device, a light emitting device and a display device according to embodiments of the present invention in conjunction with the accompanying drawings.

[0068] The inventors have found that light-emitting devices such as organic electroluminescent devices (OLEDs) usually control their color display through three independent pixel units: red, green, and blue. Since the wavelengths of red, green, and blue light are different, the required excitation energy is also different. Therefore, the properties of the light-emitting materials used in the design of red, green, and blue OLED devices are also very different, which is specifically manifested in the differences in the energy level, mobility, and optical properties of the organic materials. In addition to causing changes in device voltage, efficiency, and life, changes in the energy level and mobility of OLED materials will also cause changes in device capacitance, resistance, and other properties. Figure 1As shown, a Nyquist spectrum of the impedance spectrum of a conventional OLED and its corresponding equivalent circuit are shown. By analyzing the equivalent circuit, it can be simplified into an RC series-parallel circuit, and a simplified analysis is performed on it. The charging and discharging formula of the RC circuit is Where V0 is the initial voltage value on the capacitor, V1 is the voltage value that the capacitor can be charged or discharged, and Vt is the voltage value on the capacitor at time t. After changing it, we can get It can be seen that the charge and discharge time of OLED is proportional to the capacitance of the device. Reducing the capacitance of OLED can reduce its response time and thus improve the display quality.

[0069] like Figure 2 As shown, a typical 2T1CP metal oxide semiconductor field effect transistor (PMOS) driving circuit is shown. Figure 3 It is the process of OLED being driven to emit light. When the screen is static, the Reset potential and the Vdate write potential change periodically, and the Vdate value remains unchanged. When dragging from a bright screen to a dark screen, V date Lower, C s The internal capacitance of the device cannot be quickly replaced by R eset The circuit reaches a steady-state level, resulting in a high driving voltage for the first few frames of the OLED. After a few frames, the circuit reaches a steady state. It can be seen that if the capacitance of the OLED itself is large, the circuit will not be able to reach a steady state quickly, causing uneven brightness during the screen dragging process. If the capacitance of the red, green, and blue sub-pixels is also very different, it will cause serious display problems such as tailing and discoloration.

[0070] For organic electroluminescent devices, the increase in the concentration of diffused charges and barrier charges will lead to the characteristics of the device capacitance. For multi-layer OLEDs, changes in the mobility and energy level matching of materials will greatly affect the capacitance of the device. Therefore, the mobility matching, highest occupied molecular orbital (HOMO), and lowest unoccupied molecular orbital (LUMO) of the materials can be adjusted in a targeted manner to adjust the capacitance of the device in a direction, thereby reducing the difference in the first frame display brightness caused by the difference in capacitance between devices, and then improving the display problem of tailing and different colors.

[0071] The capacitance of organic electroluminescent devices can be roughly divided into two categories: barrier capacitance generated by charges accumulated at the interface and diffusion capacitance existing in space, such as Figure 4As shown in the figure, the capacitance of an organic electroluminescent device changes with voltage, which can help understand the principle of device capacitance generation. The process of capacitance changing with voltage is divided into four stages: Phase 1: neither holes nor electrons are injected into the device, the device can be regarded as a flat plate capacitor, and the capacitance does not change with voltage; Phase 2: charging process, charge accumulation is dominant, and the capacitance increases; Phase 3: discharging process, electrons and holes are injected into the device, positively charged holes meet with negatively charged electrons, consume the charge in the system, and the capacitance decreases; Phase 4: The capacitance decreases and even negative capacitance appears, mainly because the charge consumption rate is greater than the charge accumulation. In summary, barrier capacitance and diffusion capacitance constitute the device capacitance, holes (positive charge) that cannot be consumed by electrons (negative charge) will lead to an increase in device capacitance, and holes that cannot be consumed by charges are mainly due to the accumulation of interface charges caused by the energy level barriers and mobility differences between the various layers of OLED materials, and the increase in the amount of spatial diffusion charge caused by excessive hole injection and transmission. Therefore, to reduce the capacitance of blue-green OLED devices, the energy barrier between the layers of materials on the hole transport side should be controlled, so that holes can have good injection characteristics without generating a large amount of charge accumulation. Appropriate material mobility differences should be set so that holes can be well transported between the layers of materials without generating a large amount of spatial diffusion charges, thereby increasing the capacitance of the device. The process of interaction between the layers of materials affecting the capacitance of the device is as follows: Figure 5 shown.

[0072] Before describing a design method of a light emitting device according to an embodiment of the present application, the light emitting device is first described. Figure 6 As shown, the light-emitting device includes a substrate, a common layer and a light-emitting layer, the common layer includes an anode 400, a hole transport layer 401, a hole blocking layer 408, an electron transport layer 409, a cathode 410 and a light extraction layer 411 which are arranged in sequence along a direction away from the substrate, the light-emitting layer is located between the hole transport layer 401 and the hole blocking layer 508, the light-emitting layer includes a first light-emitting color portion, a second light-emitting color portion and a third light-emitting color portion, the first light-emitting color portion includes a first color light-emitting layer 403 and a first light-emitting color auxiliary layer 402, the second light-emitting color portion includes a second color light-emitting layer 405 and a second light-emitting color auxiliary layer 404, and the third light-emitting color portion includes a third color light-emitting layer 407 and a third light-emitting color auxiliary layer 406.

[0073] Figure 7 is a flow chart of a method for designing a light emitting device according to an embodiment of the present application. Figure 7 As shown, combined with Figure 6 According to an embodiment of the present application, a method for designing a light emitting device includes the following steps:

[0074] S101: Obtaining a capacitance of a first device, wherein the first device is one of a first light-emitting device formed by a first light-emitting color portion and a common layer, a second light-emitting device formed by a second light-emitting color portion and a common layer, and a third light-emitting device formed by a third light-emitting color portion and a common layer;

[0075] S102: According to the capacitance of the first device, adjust the capacitance of the second device so that the capacitance difference between the capacitance of the second device and the capacitance of the first device is less than a preset value, wherein the preset value is greater than or equal to 0 and less than 1.5*10 -9 F (farad), the second device is the other two of the first light-emitting device, the second light-emitting device and the third light-emitting device.

[0076] In one embodiment of the present invention, the capacitance of the second device is adjusted according to the capacitance of the first device so that the capacitance difference between the capacitance of the second device and the capacitance of the first device is less than a preset value, including: based on the capacitance of the first device, adjusting the material mobility and / or energy level of the second device to change the capacitance of the second device.

[0077] In this example, the material mobility of the second device can be achieved by at least one of the following methods: adjusting the relative substitution position of the substituent; changing the number of units with electron-pushing characteristics; adjusting the planarity of the molecule; extending the π conjugation length. Specifically, adjusting the relative substitution position of the substituent, for the same substituent, the mobility rule is para>ortho>meta; increasing the number of units with electron-pushing characteristics, introducing substituent units with stronger electron-pushing ability; adjusting the planarity of the molecule, the better the planarity of the molecule, the smaller the steric hindrance, the shorter the carrier jumping distance, and the higher the mobility; extending the π conjugation length can reduce the carrier jumping distance, thereby increasing the mobility.

[0078] The energy level of the second device is achieved by at least one of the following methods: changing the energy of the highest occupied molecular orbital and / or the lowest unoccupied molecular orbital; changing the length of the conjugated chain. Specifically, the adjustment of the substituents: electron withdrawing groups, reducing the HOMO and LUMO energies; electron donating groups, increasing the HOMO and LUMO energies; conjugated chain growth: increasing the HOMO energy and reducing the LUMO energy.

[0079] As a specific example, the first light-emitting device is a blue light device, the second light-emitting device is a green light device, and the third light-emitting device is a red light device. The blue light device includes a blue light auxiliary layer and a blue light-emitting layer, the green light device includes a green light auxiliary layer and a green light-emitting layer, and the red light device includes a red light auxiliary layer and a red light-emitting layer.

[0080] The following description takes the first light-emitting device as a blue light device, the second light-emitting device as a green light device, and the third light-emitting device as a red light device as an example. Then, assuming the first device is the third light-emitting device, and the second device is the first and second light-emitting devices, the design of the first light-emitting device should satisfy: the difference between the absolute value of the highest occupied molecular orbital of the first light-emitting color auxiliary layer and the absolute value of the highest occupied molecular orbital of the hole transport layer is greater than the first preset energy value and less than the second preset energy value; the difference between the absolute value of the highest occupied molecular orbital of the first color light-emitting layer and the absolute value of the highest occupied molecular orbital of the first light-emitting color auxiliary layer is greater than the third preset energy value and less than the fourth preset energy value; the ratio of the material mobility between the hole transport layer and the first light-emitting color auxiliary layer is greater than the first preset mobility and less than the second preset mobility; the ratio of the material mobility between the first light-emitting color auxiliary layer and the first color light-emitting layer is greater than the third preset mobility and less than the fourth preset mobility. Example of the design of the first light-emitting device: 0.15ev < |HOMO BPrime |-|HOMO HT |<0.3ev, 0.2ev < |HOMO BH |-|HOMO BPrime |<0.4ev, 100 < Mobility(HTL) / Mobility(BPrime) < 1000, 1000 < Mobility(BPrime) / Mobility(BH) < 100000. Where, Mobility refers to the material mobility.

[0081] The second light-emitting device satisfies: the difference between the absolute value of the highest occupied molecular orbital of the second light-emitting color auxiliary layer and the absolute value of the highest occupied molecular orbital of the hole transport layer is less than the fifth preset energy value; the difference between the absolute value of the highest occupied molecular orbital of the second color light-emitting layer and the absolute value of the highest occupied molecular orbital of the second light-emitting color auxiliary layer is less than the sixth preset energy value; the material mobility of the hole transport layer is greater than the material mobility between the second light-emitting color auxiliary layers; the material mobility of the second light-emitting color auxiliary layer is greater than the material mobility of the green light-emitting layer. Example of the design of the second light-emitting device: |HOMO GPrime |-|HOMO HT |<0.15ev, |HOMO GH |-|HOMO G Prime |<0.15ev, Mobility(HTL) > Mobility(GPrime), Mobility(GPrime) > Mobility(GH).

[0082] That is to say, in order to improve the problem of display tailing and different colors caused by the different brightness of the first frame of red, green and blue, the structures of the third light-emitting device, the second light-emitting device and the first light-emitting device are designed in a targeted manner. The capacitance of the third light-emitting device can be used as a reference to adjust the capacitance of the structure of the second light-emitting device and the first light-emitting device to the same level as the capacitance of the third light-emitting device, that is, less than a preset value. Thereby, the difference in the brightness of the first frame of the light-emitting device caused by the difference in capacitance between the device structures can be reduced.

[0083] In one embodiment of the present invention, the material of the hole transport layer is a mixed material, and the adjustment of the material mobility and / or energy level of the second device includes: adjusting the proportion of the mixed material in the material of the hole transport layer to change the material mobility and / or energy level of the second device. That is to say, for the material of the hole transport layer composed of a mixed material, in addition to adjusting the material energy level and mobility by the above method, the mixing ratio of the electron transport type and the hole transport type monomer material can also be adjusted. If you want to increase the hole mobility of the light-emitting layer material, you can increase the proportion of the hole transport type monomer. If you want to increase the electron mobility, you can increase the proportion of the electron transport type monomer.

[0084] According to the design method of the light-emitting device of the embodiment of the present invention, the capacitance of the first light-emitting device, the second light-emitting device and the third light-emitting device are adjusted so that the capacitance of the first light-emitting device, the second light-emitting device and the third light-emitting device are at the same level, thereby reducing the brightness difference of the first frame of the device caused by the difference in capacitance between the device structures, that is, by limiting the physical properties of the functional layer material of the light-emitting device, the capacitance difference between the first light-emitting device, the second light-emitting device and the third light-emitting device can be greatly reduced, and the brightness difference of the first frame of the light-emitting device caused by the difference in capacitance between the device structures is reduced, thereby improving the display poor phenomenon of the light-emitting device such as AMOLD tailing and heterochromaticity, and enhancing the display effect of the light-emitting device.

[0085] The advantages of the design method of the light emitting device according to the embodiment of the present invention are described below through experimental data. Figure 6 As shown, by adjusting the material energy level and mobility of the virtual transmission layer auxiliary layer and the light-emitting layer, the capacitance of the device is regulated. The embodiment of the present invention is compared with the reference ratio, wherein the reference ratio is a light-emitting device in the prior art, and the light-emitting device used in the embodiment of the invention example is a light-emitting device after the capacitance is regulated by the design method. The specific physical property data are shown in Table 1 below:

[0086] Table 1

[0087]

[0088] The capacitance of the first light emitting device and the second light emitting device in the reference example and the embodiment of the present invention are measured respectively. Figure 8As shown, the test conditions are 1000 Hz frequency, 100 mV perturbation, scanning the capacitance from zero volt to 5 volts, and taking the maximum capacitance as a comparison, to obtain the data in Table 2, as shown in Table 2:

[0089] Table 2

[0090]

[0091] In the above description, the first light-emitting device is a blue light device, the second light-emitting device is a green light device, and the third light-emitting device is a red light device. It can be seen that by adjusting the physical properties of the materials of each layer of the device to the conditions set by the design method of the embodiment of the present invention, the maximum capacitance difference of the three light-emitting devices, red, green and blue, is reduced from 3.61E-09 farads to 1.02E-09 farads, with a reduction of 71.7%, thereby improving the large difference in brightness of the first frame caused by the large difference in capacitance between devices, resulting in poor display such as tailing and different colors, and effectively improving the display effect of the light-emitting device.

[0092] The embodiment of the present invention further provides a light-emitting device, comprising: a substrate; a common layer, the common layer comprising an anode, a hole transport layer, a hole blocking layer, an electron transport layer, a cathode and a light extraction layer arranged in sequence in a direction away from the substrate; a light-emitting layer, the light-emitting layer being located between the hole transport layer and the hole blocking layer, the light-emitting layer comprising a first light-emitting color portion, a second light-emitting color portion and a third light-emitting color portion, wherein a capacitance difference between a first light-emitting device formed by the first light-emitting color portion and the common layer, a second light-emitting device formed by the second light-emitting color portion and the common layer, and a third light-emitting device formed by the third light-emitting color portion and the common layer is less than a preset value, and the preset value is greater than or equal to 0 and less than 1.5*10 -9 F.

[0093] In a specific example of the present invention, the first light emitting device is a blue light device, and the second light emitting device is a green light device, wherein:

[0094] The blue light device meets the following requirements:

[0095] 0.15ev<|HOMO BPrime |-|HOMO HT |<0.3ev,

[0096] 0.2ev<|HOMO BH |-|HOMO BPrime |<0.4ev;

[0097] The green light device meets the following requirements:

[0098] |HOMO GPrime |-|HOMOHT |<0.15ev,

[0099] |HOMO GH |-|HOMO GPrime |<0.15ev;

[0100] Wherein, the HOMO BPrime is the highest occupied molecular orbital of the blue light auxiliary layer of the blue light device, the HOMO HT is the highest occupied molecular orbital of the hole transport layer, the HOMO BH is the highest occupied molecular orbital of the blue light emitting layer of the blue light device, the HOMO GPrime is the highest occupied molecular orbital of the green light auxiliary layer of the green light device, the HOMO GH It is the highest occupied molecular orbital of the green light-emitting layer of the green light-emitting device.

[0101] Furthermore, the absolute value of the difference between the highest occupied molecular orbital of the blue light auxiliary layer and the hole transport layer is 0.16, the absolute value of the difference between the highest occupied molecular orbital of the blue light-emitting layer and the blue light auxiliary layer is 0.31, the absolute value of the difference between the highest occupied molecular orbital of the green light auxiliary layer and the hole transport layer is 0.18, and the absolute value of the difference between the highest occupied molecular orbital of the green light-emitting layer and the green light auxiliary layer is 0.06.

[0102] In a specific example of the present invention, the blue light device further satisfies:

[0103] 100 <Mobility(HTL) / Mobility(BPrime)<1000,

[0104] 1000 <Mobility(BPrime) / Mobility(BH)<100000;

[0105] The green light device meets the following requirements:

[0106] Mobility(HTL)>Mobility(GPrime),

[0107] Mobility(GPrime)>Mobility(GH);

[0108] Among them, the Mobility (HTL) is the material mobility of the hole transport layer, the Mobility (BPrime) is the material mobility of the blue light auxiliary layer, the Mobility (BH) is the material mobility of the blue light-emitting layer, the Mobility (GPrime) is the material mobility of the green light auxiliary layer, and the Mobility (GH) is the material mobility of the green light-emitting layer.

[0109] In this example, the ratio of the material mobility between the hole transport layer and the blue light auxiliary layer is 159, the ratio of the material mobility between the blue light auxiliary layer and the blue light-emitting layer is 18000, the ratio of the material mobility between the hole transport layer and the green light auxiliary layer is 24, and the ratio of the material mobility between the green light auxiliary layer and the green light-emitting layer is 32.

[0110] In some examples, the capacitance of the first light emitting device, the second light emitting device, and the third light emitting device is changed by adjusting material mobility and / or energy levels.

[0111] According to the light-emitting device of the embodiment of the present invention, the capacitance of the first light-emitting device, the second light-emitting device and the third light-emitting device are adjusted so that the capacitance of the first light-emitting device, the second light-emitting device and the third light-emitting device are at the same level, thereby reducing the brightness difference of the first frame of the device caused by the difference in capacitance between the device structures, that is, by limiting the physical properties of the functional layer material of the light-emitting device, the capacitance difference between the first light-emitting device, the second light-emitting device and the third light-emitting device can be greatly reduced, and the brightness difference of the first frame of the light-emitting device caused by the difference in capacitance between the device structures is reduced, thereby improving the display poor phenomenon of the light-emitting device such as AMOLD tailing and heterochromaticity, and enhancing the display effect of the light-emitting device.

[0112] Furthermore, an embodiment of the present invention provides a display device, comprising: a light emitting device according to any one of the above embodiments. The display device according to the embodiment of the present invention has the advantage of good display effect.

[0113] The flowchart and block diagram in the accompanying drawings illustrate the possible architecture, functions and operations of the processing receiving device, method and computer program product according to various embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment, or a part of the code, and the aforementioned module, program segment, or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of the boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based electronic device that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0114] The units or modules involved in the embodiments described in the present application may be implemented by software or hardware. The units or modules described may also be set in a processor, and the processor is used to implement a vision protection method for an electronic device when executing the program: obtaining user data collected by a first camera and user depth data collected by a second camera; obtaining the user's viewing distance based on the user data and the user depth data; and determining whether to start a vision protection strategy based on the user's viewing distance.

[0115] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the aforementioned disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A method for designing a light emitting device, characterized in that: The light-emitting device comprises a substrate, a common layer and a light-emitting layer, wherein the common layer comprises an anode, a hole transport layer, a hole blocking layer, an electron transport layer, a cathode and a light extraction layer arranged in sequence in a direction away from the substrate, the light-emitting layer is located between the hole transport layer and the hole blocking layer, the light-emitting layer comprises a first light-emitting color portion, a second light-emitting color portion and a third light-emitting color portion, the first light-emitting color portion comprises a first color light-emitting layer and a first light-emitting color auxiliary layer, the second light-emitting color portion comprises a second color light-emitting layer and a second light-emitting color auxiliary layer, and the third light-emitting color portion comprises a third color light-emitting layer and a third light-emitting color auxiliary layer, and the method comprises: Obtaining a capacitance of a first device, the first device being one of a first light-emitting device formed by the first light-emitting color portion and the common layer, a second light-emitting device formed by the second light-emitting color portion and the common layer, and a third light-emitting device formed by the third light-emitting color portion and the common layer; Based on the capacitance of the first device, the capacitance of the second device is adjusted so that the capacitance difference between the capacitance of the second device and the capacitance of the first device is less than a preset value, wherein the preset value is greater than or equal to 0 and less than 1.5*10 -9 F, the second device is the other two of the first light-emitting device, the second light-emitting device and the third light-emitting device.

2. The method for designing a light emitting device according to claim 1, characterized in that: The adjusting the capacitance of the second device based on the capacitance of the first device so that the capacitance difference between the capacitance of the second device and the capacitance of the first device is less than a preset value includes: Based on the capacitance of the first device, material mobility and / or energy level of the second device is adjusted to change the capacitance of the second device.

3. The method for designing a light emitting device according to claim 2, characterized in that: The material mobility of the second device is achieved by at least one of the following methods: Adjust the relative substitution positions of substituents; Changing the number of units with push-electron characteristics; Adjust the planarity of the molecule; Extend the π conjugation length.

4. The method for designing a light emitting device according to claim 3, characterized in that: The energy level of the second device is achieved by at least one of the following methods: changing the energy of the highest occupied molecular orbital and / or the lowest unoccupied molecular orbital; Vary the length of the conjugated chain.

5. The method for designing a light emitting device according to claim 4, characterized in that: The first device is the third light emitting device, the second device is the first light emitting device and the second light emitting device, The first light emitting device satisfies: The difference between the absolute value of the highest occupied molecular orbital of the first luminescent color auxiliary layer and the absolute value of the highest occupied molecular orbital of the hole transport layer is greater than a first preset energy value and less than a second preset energy value; The difference between the absolute value of the highest occupied molecular orbital of the first color light-emitting layer and the absolute value of the highest occupied molecular orbital of the first light-emitting color auxiliary layer is greater than the third preset energy value and less than the fourth preset energy value; The ratio of the material mobility between the hole transport layer and the first light-emitting color auxiliary layer is greater than a first preset mobility and less than a second preset mobility; A ratio of material mobility between the first light-emitting color auxiliary layer and the first color light-emitting layer is greater than a third preset mobility and less than a fourth preset mobility.

6. The method for designing a light emitting device according to claim 5, characterized in that: The second light emitting device satisfies: The difference between the absolute value of the highest occupied molecular orbital of the second luminescent color auxiliary layer and the absolute value of the highest occupied molecular orbital of the hole transport layer is less than a fifth preset energy value; The difference between the absolute value of the highest occupied molecular orbital of the second color light-emitting layer and the absolute value of the highest occupied molecular orbital of the second color light-emitting auxiliary layer is less than a sixth preset energy value; The material mobility of the hole transport layer is greater than the material mobility between the second light-emitting color auxiliary layers; The material mobility of the second light-emitting color auxiliary layer is greater than the material mobility of the green light-emitting layer.

7. The method for designing a light emitting device according to claim 2, characterized in that: The material of the hole transport layer is a mixed material, and the step of adjusting the material mobility and / or energy level of the second device includes: The proportion of the mixed material in the material of the hole transport layer is adjusted to change the material mobility and / or energy level of the second device.

8. A light emitting device, characterized in that: include: substrate substrate; A common layer, the common layer comprising an anode, a hole transport layer, a hole blocking layer, an electron transport layer, a cathode and a light extraction layer arranged in sequence in a direction away from the substrate; a light-emitting layer, the light-emitting layer being located between the hole transport layer and the hole blocking layer, the light-emitting layer comprising a first light-emitting color portion, a second light-emitting color portion and a third light-emitting color portion, The capacitance difference between the first light-emitting device formed by the first light-emitting color portion and the common layer, the second light-emitting device formed by the second light-emitting color portion and the common layer, and the third light-emitting device formed by the third light-emitting color portion and the common layer is less than a preset value, and the preset value is greater than or equal to 0 and less than 1.5*10 -9 F.

9. The light emitting device according to claim 8, characterized in that: The first light emitting device is a blue light device, and the second light emitting device is a green light device, wherein: The blue light device meets the following requirements: 0.15ev<|HOMO BPrime |-|HOMO HT |<0.3ev, 0.2ev<|HOMO BH |-|GAMO BPrime |<0.4ev; The green light device meets the following requirements: |HOMO GPrime |-|HOMO HT |<0.15ev, |HOMO GH |-|HOMO GPrime |<0.15ev; Wherein, the HOMO BPrime is the highest occupied molecular orbital of the blue light auxiliary layer of the blue light device, the HOMO HT is the highest occupied molecular orbital of the hole transport layer, the HOMO BH is the highest occupied molecular orbital of the blue light emitting layer of the blue light device, the HOMO GPrime is the highest occupied molecular orbital of the green light auxiliary layer of the green light device, the HOMO GH It is the highest occupied molecular orbital of the green light-emitting layer of the green light-emitting device.

10. The light emitting device according to claim 9, characterized in that: The absolute value of the difference between the highest occupied molecular orbital of the blue light auxiliary layer and the hole transport layer is 0.16, the absolute value of the difference between the highest occupied molecular orbital of the blue light-emitting layer and the blue light auxiliary layer is 0.31, the absolute value of the difference between the highest occupied molecular orbital of the green light auxiliary layer and the hole transport layer is 0.18, and the absolute value of the difference between the highest occupied molecular orbital of the green light-emitting layer and the green light auxiliary layer is 0.

06.

11. The light emitting device according to claim 9, characterized in that: The blue light device meets the following requirements: 100 <Mobility(HTL) / Mobility(BPrime)<1000, 1000<Mobility(BPrime) / Mobility(BH) <100000; The green light device meets the following requirements: Mobility(HTL)>Mobility(GPrime), Mobility(GPrime)>Mobility(GH); Among them, the Mobility (HTL) is the material mobility of the hole transport layer, the Mobility (BPrime) is the material mobility of the blue light auxiliary layer, the Mobility (BH) is the material mobility of the blue light-emitting layer, the Mobility (GPrime) is the material mobility of the green light auxiliary layer, and the Mobility (GH) is the material mobility of the green light-emitting layer.

12. The light emitting device according to claim 11, characterized in that: The material mobility ratio between the hole transport layer and the blue light auxiliary layer is 159, the material mobility ratio between the blue light auxiliary layer and the blue light-emitting layer is 18000, the material mobility ratio between the hole transport layer and the green light auxiliary layer is 24, and the material mobility ratio between the green light auxiliary layer and the green light-emitting layer is 32.

13. The light emitting device according to claim 8, characterized in that: The capacitance of the first light emitting device, the second light emitting device and the third light emitting device is changed by adjusting the material mobility and / or energy level.

14. A display device, characterized in that: include: A light emitting device according to any one of claims 8 to 13.

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