Display panel and mobile terminal

Abstract

The embodiments of the present application provide a display panel and a mobile terminal; the display panel has multiple light-emitting devices, and the light-emitting devices include a microcavity, wherein multiple light-emitting devices displaying the same color form a light-emitting device group, and in at least one light-emitting device group, the length of the microcavity of each light-emitting device is greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group; the above-mentioned display panel makes the length of the microcavity of each light-emitting device in at least one light-emitting device group greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group, so that the microcavity emission peak of the light-emitting device is offset from the intrinsic main emission peak and is located on the right side of the intrinsic main emission peak. When the observation angle increases, the microcavity emission peak of the light-emitting device moves toward the direction close to the intrinsic main emission peak as the observation angle increases, so as to minimize the blue shift of the spectrum at different viewing angles.

Description

Technical Field

[0001] The present application relates to the field of display, and in particular to a display panel and a mobile terminal. Background Art

[0002] Organic Light-emitting Diode (OLED) has the advantages of high efficiency, high contrast, high response speed, etc., and has been used more and more widely in recent years. According to the light emission mode, OLED can be divided into two types: bottom emission type and top emission type. The light emission efficiency of the bottom emission structure is limited by the aperture ratio of the panel, and it is difficult to effectively use the light source. To achieve the required brightness, the OLED light-emitting device must operate at a high brightness state, and its luminous efficiency is not high and its service life is short. The top emission structure avoids the influence of the bottom line of the panel, and the aperture ratio is improved, and its luminous efficiency and service life are improved.

[0003] Currently, in top-emitting OLED devices, there is a strong Fabry microcavity effect between the cathode layer of semi-reflective and semi-transparent metal materials, the organic light-emitting functional layer, and the anode layer of fully reflective metal materials. This microcavity allows light to interfere at a wide angle and with multiple beams in the cavity. Interference will significantly narrow the spectrum emitted by the top-emitting OLED device, and also greatly enhance the emission intensity relative to devices without a microcavity structure. However, this microcavity will cause the emission spectrum of the top-emitting OLED device to blue-shift as the viewing angle increases, resulting in deterioration of brightness and chromaticity viewing angle, making it difficult to achieve a wide viewing angle.

[0004] Therefore, there is an urgent need for a display panel and a mobile terminal to solve the above technical problems. Summary of the invention

[0005] The embodiments of the present application provide a display panel and a mobile terminal, which can improve the technical problem of chromaticity shift after changing the viewing angle in the existing display panel with a microcavity structure.

[0006] The embodiment of the present application provides a display panel, including a first substrate and a plurality of light-emitting devices disposed on the first substrate, wherein the light-emitting devices include a first electrode and a second electrode disposed opposite to each other, and a microcavity formed between the first electrode and the second electrode;

[0007] Among them, the multiple light-emitting devices include multiple light-emitting device groups for displaying different light-emitting colors, and each of the light-emitting device groups includes multiple light-emitting devices displaying the same color; in at least one of the light-emitting device groups, the length of the microcavity of each of the light-emitting devices is greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group.

[0008] Optionally, in some embodiments of the present application, the display panel further comprises an organic light-emitting functional layer disposed in the microcavity, and when the length of the microcavity of the light-emitting device is equal to the resonance cavity length of the wavelength of light of the color displayed by the light-emitting device group, the thickness of the organic light-emitting functional layer in the light-emitting device is a first thickness;

[0009] Wherein, in at least one of the light-emitting device groups, the thickness of the organic light-emitting functional layer in each of the light-emitting devices is greater than the first thickness.

[0010] Optionally, in some embodiments of the present application, the peak wavelength of the light emitted by the organic light-emitting functional layer at a first preset viewing angle is a first peak wavelength, and the peak wavelength of the light emitted by the organic light-emitting functional layer at a second preset viewing angle is a second peak wavelength;

[0011] The second preset viewing angle is greater than the first preset viewing angle, and the second peak wavelength is smaller than the first peak wavelength.

[0012] Optionally, in some embodiments of the present application, when the first preset viewing angle and the second preset viewing angle are both within a preset viewing angle range, the brightness value of the light emitted by the organic light-emitting functional layer at the second preset viewing angle is greater than the brightness value of the light emitted by the organic light-emitting functional layer at the first preset viewing angle.

[0013] Optionally, in some embodiments of the present application, the organic light-emitting functional layer includes any one of a red light-emitting functional layer, a green light-emitting functional layer and a blue light-emitting functional layer;

[0014] Wherein, the thickness of the red light-emitting functional layer is greater than the thickness of the green light-emitting functional layer, and the thickness of the green light-emitting functional layer is greater than the thickness of the blue light-emitting functional layer.

[0015] Optionally, in some embodiments of the present application, the red light-emitting functional layer, the green light-emitting functional layer, and the blue light-emitting functional layer each include a hole injection layer disposed on the first electrode, a hole transport layer disposed on the hole injection layer, a light-emitting layer disposed on the hole transport layer, an electron transport layer disposed on the light-emitting layer, and an electron injection layer disposed on the electron transport layer;

[0016] Among them, the thickness of the hole transport layer corresponding to the red light-emitting functional layer is greater than the thickness of the hole transport layer corresponding to the green light-emitting functional layer, and the thickness of the hole transport layer corresponding to the green light-emitting functional layer is greater than the thickness of the hole transport layer corresponding to the blue light-emitting functional layer.

[0017] Optionally, in some embodiments of the present application, the display panel further includes a second substrate disposed opposite to the first substrate and a color filter film disposed on the second substrate and close to a side of the first substrate;

[0018] Wherein, the transmission spectrum of the color filter film matches the emission spectrum of the organic light-emitting functional layer.

[0019] Optionally, in some embodiments of the present application, the color filter film includes a red color resist, a green color resist and a blue color resist respectively arranged corresponding to the red light-emitting functional layer, the green light-emitting functional layer and the blue light-emitting functional layer;

[0020] Among them, the absolute value of the difference between the peak transmittance wavelength of the red color resist and the peak emission wavelength of the red light-emitting functional layer, the absolute value of the difference between the peak transmittance wavelength of the green color resist and the peak emission wavelength of the green light-emitting functional layer, and the absolute value of the difference between the peak transmittance wavelength of the blue color resist and the peak emission wavelength of the blue light-emitting functional layer are all less than the preset difference.

[0021] Optionally, in some embodiments of the present application, the reflectivity of the first electrode is greater than the reflectivity of the second electrode, and the transmittance of the first electrode is less than the transmittance of the second electrode.

[0022] Correspondingly, an embodiment of the present application further provides a mobile terminal, comprising a terminal body and a display panel as described in any one of the above items, wherein the terminal body and the display panel are combined into one.

[0023] The embodiment of the present application provides a display panel and a mobile terminal; the display panel includes a first substrate and a plurality of light-emitting devices arranged on the first substrate, the light-emitting devices include a first electrode and a second electrode arranged opposite to each other, and a microcavity formed between the first electrode and the second electrode, wherein a plurality of the light-emitting devices displaying the same color form a light-emitting device group, and in at least one of the light-emitting device groups, the length of the microcavity of each light-emitting device is greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group; the display panel makes the length of the microcavity of each light-emitting device in at least one of the light-emitting device groups greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group, so that the microcavity emission peak of the light-emitting device is offset from the intrinsic main emission peak and is located on the right side of the intrinsic main emission peak, and when the viewing angle increases, the microcavity emission peak of the light-emitting device moves toward the direction close to the intrinsic main emission peak as the viewing angle increases, thereby reducing the brightness loss of the light-emitting device caused by the increase in the viewing angle, and at the same time minimizing the blue shift of the spectrum at different viewing angles, thereby producing an effect of preventing color deviation, and further realizing the wide viewing angle display of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of the structure of a first display panel provided in an embodiment of the present application;

[0026] Figure 2 A light emitting spectrum diagram of a green light emitting functional layer at different cavity lengths in the first display panel provided in an embodiment of the present application;

[0027] Figure 3 A graph showing the brightness characteristics of the green light-emitting functional layer at different viewing angles in the first display panel provided in an embodiment of the present application;

[0028] Figure 4 A schematic diagram showing the relationship between the white light viewing angle and the brightness ratio of the first display panel under different cavity lengths provided in an embodiment of the present application;

[0029] Figure 5 A schematic cross-sectional view of a second display panel provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; and "inside" and "outside" refer to the outline of the device.

[0031] The embodiments of the present application are directed to the technical problem that the chromaticity shifts after the viewing angle is changed in the existing display panels with microcavities. The embodiments of the present application can improve the above technical problem.

[0032] The technical solution of the present application is now described in conjunction with specific embodiments.

[0033] See also Figures 1 to 5, an embodiment of the present application provides a display panel 100 and a mobile terminal; the display panel 100 includes a first substrate 11 and a plurality of light-emitting devices arranged on the first substrate 11, the light-emitting devices include a first electrode 13 and a second electrode 15 arranged opposite to each other, and a microcavity 20 formed between the first electrode 13 and the second electrode 15, wherein a plurality of the light-emitting devices displaying the same color form a light-emitting device group, and in at least one of the light-emitting device groups, the length of the microcavity 20 of each light-emitting device is greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group.

[0034] The display panel 100 provided in the embodiment of the present application makes the length of the microcavity 20 of each of the light-emitting devices in at least one of the light-emitting device groups greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group, so that the microcavity emission peak of the light-emitting device is offset from the intrinsic main emission peak and is located on the right side of the intrinsic main emission peak. When the viewing angle increases, the microcavity emission peak of the light-emitting device moves toward the direction close to the intrinsic main emission peak as the viewing angle increases, so as to minimize the blue shift of the spectrum at different viewing angles, thereby producing an effect of preventing color deviation, and further realizing the wide-viewing angle display of the display panel 100.

[0035] The technical solution of the present application is now described in conjunction with specific embodiments.

[0036] Embodiment 1

[0037] like Figure 1 , which is a schematic structural diagram of a first display panel 100 provided in an embodiment of the present application; wherein the display panel 100 includes a first substrate 11, a thin film transistor array layer 12 disposed on the first substrate 11, and a plurality of light-emitting devices disposed on the thin film transistor array layer 12;

[0038] Among them, the multiple light-emitting devices include multiple light-emitting device groups for displaying different light-emitting colors, and each of the light-emitting device groups includes multiple light-emitting devices displaying the same color; in at least one of the light-emitting device groups, the length of the microcavity 20 of each of the light-emitting devices is greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group.

[0039] Specifically, the first substrate 11 is a transparent rigid substrate or a transparent flexible substrate, the transparent rigid substrate may be a glass substrate, and the material of the flexible substrate includes at least one of a polyester compound and a polyimide compound. In the embodiment of the present invention, the first substrate 11 is a glass substrate.

[0040] Specifically, the display panel 100 further includes a pixel definition layer 16 disposed on the first substrate 11 , the pixel definition layer 16 is provided with a plurality of through holes, and the plurality of light emitting devices are respectively disposed in the plurality of through holes.

[0041] Furthermore, the plurality of through holes on the pixel definition layer 16 are all tapered, and the pixel definition layer 16 is made of an organic insulating material, preferably polyimide.

[0042] In the embodiment of the present application, the light-emitting device includes a first electrode 13 and a second electrode 15 arranged opposite to each other, a microcavity 20 formed between the first electrode 13 and the second electrode 15, and an organic light-emitting functional layer 14 arranged in the microcavity 20. The first electrode 13, the organic light-emitting functional layer 14, and the second electrode 15 are arranged in sequence along the light emitting direction of the organic light-emitting functional layer 14.

[0043] In the embodiment of the present application, the material of the first electrode 13 is a fully reflective metal material, and the material of the second electrode 15 is a semi-reflective and semi-transmissive metal material; wherein the reflectivity of the first electrode 13 is greater than the reflectivity of the second electrode 15, and the transmittance of the first electrode 13 is less than the transmittance of the second electrode 15. Therefore, the first electrode 13 can be used as a fully reflective layer of the microcavity 20, and the second electrode 15 can be used as a semi-transmissive and semi-reflective layer of the microcavity 20. Due to the reflection effect of the fully reflective layer and the semi-reflective layer on the light, the light will be reflected multiple times in the microcavity 20, and only the light of a specific wavelength can be emitted, thereby increasing the luminous intensity and improving the luminous efficiency.

[0044] Furthermore, the first electrode 13 needs to have good electrical conductivity and light transmittance. In some embodiments, the first electrode 13 is made of transparent ITO (indium tin oxide). ITO is an N-type semiconductor-indium tin oxide, which has good electrical conductivity and is close to the electrical conductivity of metal; the electrical conductivity and light transmittance of ITO can be adjusted by controlling the ratio of indium oxide and tin oxide in ITO. Increasing the ratio of indium oxide can increase the light transmittance of ITO, and increasing the ratio of tin oxide will increase the electrical conductivity of ITO and reduce the light transmittance. In order to ensure a good display effect, the light transmittance of ITO is preferably above 90%. The ratio of indium oxide and tin oxide in ITO can be adjusted to achieve a balance between electrical conductivity and light transmittance.

[0045] Furthermore, the second electrode 15, as the semi-reflective and semi-transmissive layer of the microcavity 20, needs to have good conductivity and stability, and can be made of a low work function alloy material. In some embodiments, the second electrode 15 is made of a magnesium-silver alloy, which has good conductivity and is easy to make. It should be noted that, if the cost permits, the second electrode 15 can also be made of other alloys that meet the performance requirements, such as aluminum-silver alloy, etc., which are not limited here.

[0046] In an embodiment of the present application, the organic light-emitting functional layer 14 includes any one of a red light-emitting functional layer 141, a green light-emitting functional layer 142 and a blue light-emitting functional layer 143; wherein the red light-emitting functional layer 141, the green light-emitting functional layer 142 and the blue light-emitting functional layer 143 all include a hole injection layer arranged on the first electrode 13, a hole transport layer arranged on the hole injection layer, a light-emitting layer arranged on the hole transport layer, an electron transport layer arranged on the light-emitting layer, and an electron injection layer arranged on the electron transport layer.

[0047] Furthermore, the hole injection layer is used to help holes be injected from the first electrode 13 into the hole transport layer respectively, and its material is selected from organic small molecule hole injection material and polymer hole injection material. The hole injection layer is prepared by liquid phase film forming method, specifically by inkjet printing method or nozzle printing method. The hole injection layer material is preferably poly(3,4-ethylenedioxythiophene):polystyrene sulphonate) (poly(ethylenedioxythiophene):polystyrene sulphonate, PEDT:PSS), and the preferred film thickness is 10nm.

[0048] Specifically, the hole transport layer is used to transport holes from the hole injection layer to the light-emitting layer, and its material is selected from organic small molecule hole transport materials and polymer hole transport materials. The hole transport layer is prepared by a liquid phase film forming method, specifically an inkjet printing method or a nozzle printing method. The material of the hole transport layer is preferably poly(9-vinlycarbazole) (PVK), and the preferred film thickness is 20 nm.

[0049] Specifically, the electron transport layer is used to help electrons be transported from the second electrode 15 to the light-emitting layer, and its material is selected from organic small molecule electron transport materials and polymer electron transport materials, wherein the organic small molecule electron transport material can be formed into a film by vacuum evaporation, or by a liquid phase film forming method such as inkjet printing and nozzle printing, and the polymer electron transport material is formed into a film by a liquid phase film forming method such as inkjet printing and nozzle printing, and the material of the hole transport layer is preferably tri(8-hydroxyquinoline lithium) (tri(8-quinolinolato)aluminum, Liq3), and the preferred film thickness is 30nm.

[0050] In the embodiments of the present application, the manufacturing process of the light-emitting device generally includes vacuum thermal evaporation and inkjet printing, wherein the inkjet printing technology is to directly drop ink containing OLED material into a pre-fabricated pixel definition layer 16, and form a desired pattern after the solvent evaporates; compared with the vacuum thermal evaporation method, the inkjet printing technology has the advantages of saving materials, mild process materials, and uniform film formation; it should be noted that when manufacturing the OLED light-emitting layer, the process can be selected according to actual conditions, and is not limited here.

[0051] In the embodiment of the present application, when the light is reflected back and forth multiple times in the microcavity 20 and finally emerges from the microcavity 20, the cavity length and the wavelength of the emergent light satisfy Formula 1: m*λ0 / 2=nL, where m is a positive integer, λ0 is the initial wavelength of the microcavity emission peak of the light at a preset viewing angle, L is the cavity length of the microcavity 20, and n is the refractive index of the organic material; it can be seen from the above Formula 1 that the cavity length L of the microcavity 20 is positively correlated with the wavelength λ0 of the microcavity emission peak of the light; where, in order to maximize the light extraction efficiency of the light-emitting device, it is necessary to make the wavelength of the microcavity emission peak the same as the wavelength of the intrinsic emission peak of the light, where the intrinsic emission peak refers to the emission peak in the spectrum of the light emitted by the material itself, which can be used to characterize the luminescence properties of the material itself.

[0052] Specifically, the peak wavelength of the intrinsic emission peak in the blue light band may be between 450nm and 470nm, such as 460nm; the peak wavelength of the intrinsic emission peak in the green light band may be between 520nm and 550nm, such as 530nm; the peak wavelength of the intrinsic emission peak in the red light band may be between 610nm and 700nm, such as 620nm. That is, the wavelength of the intrinsic emission peak in the red light band is greater than that of the intrinsic emission peak in the green light band, and the wavelength of the intrinsic emission peak in the green light band is greater than that of the intrinsic emission peak in the blue light band.

[0053] Therefore, in order to optimize the light extraction efficiency of the light-emitting devices of different colors, the thickness of the red light-emitting functional layer 141 is greater than the thickness of the green light-emitting functional layer 142, and the thickness of the green light-emitting functional layer 142 is greater than the thickness of the blue light-emitting functional layer 143. This design makes the cavity length of the red light-emitting device greater than the cavity length of the green light-emitting device, and the cavity length of the green light-emitting device greater than the cavity length of the blue light-emitting device.

[0054] Furthermore, the thickness of the hole transport layer corresponding to the red light-emitting functional layer 141 is greater than the thickness of the hole transport layer corresponding to the green light-emitting functional layer 142, and the thickness of the hole transport layer corresponding to the green light-emitting functional layer 142 is greater than the thickness of the hole transport layer corresponding to the blue light-emitting functional layer 143.

[0055] like Figure 2 As shown, it is a luminescence spectrum diagram of the green light-emitting functional layer 142 at different cavity lengths in the first display panel 100 provided in an embodiment of the present application, wherein the horizontal axis is the wavelength (Wavelength, unit: nm), and the vertical axis is the ratio of the green light brightness L1 to the green light initial brightness L0, and the green light initial brightness L0 is the brightness corresponding to the wavelength of the intrinsic emission peak emitted by the material of the green light-emitting functional layer 142.

[0056] Specifically, the first curve c1 (dashed part) is the intrinsic characteristic curve of the material of the green light-emitting functional layer 142, and the intrinsic emission spectrum refers to the spectrum of light emitted by the material itself, which can be used to characterize the luminescence characteristics of the material itself, and the wavelength of the intrinsic emission peak of the intrinsic emission spectrum is about 520nm; the second curve c2 is the microcavity characteristic curve when the thickness of the green light-emitting functional layer 142 is the first thickness; the third curve c3 is the microcavity characteristic curve when the thickness of the green light-emitting functional layer 142 is the second thickness, and the second thickness is greater than the first thickness (at this time, the wavelength of the microcavity emission peak is also about 540nm).

[0057] Among them, in the light-emitting device group displaying green, when the length of the microcavity 20 of each of the light-emitting devices is equal to the resonance cavity length of the wavelength of the light displayed by the light-emitting device group displaying green, the thickness of the green light-emitting functional layer 142 in the light-emitting device is the first thickness; at this time, the microcavity emission peak of the green light-emitting functional layer 142 coincides with the intrinsic emission peak (the wavelength of the microcavity emission peak is also around 520nm), so that the light extraction efficiency of the green light-emitting functional layer 142 is the highest. Because the microcavity 20 causes the green light to perform wide-angle interference and multi-beam interference in the cavity, the microcavity characteristic curve on the right side of the microcavity emission peak is significantly narrowed (the curve on the right side of the microcavity emission peak is smaller than the intrinsic characteristic curve).

[0058] Furthermore, since the second thickness is greater than the first thickness, the microcavity characteristic curve of the green light-emitting functional layer 142 is right-biased, that is, the microcavity emission peak of the third curve c3 is located to the right of the microcavity emission peak of the second curve c2. This is because when the thickness of the green light-emitting functional layer 142 is increased, the length of the microcavity 20 of the green light-emitting device increases, thereby making the wavelength of the microcavity emission peak of the third curve c3 greater than the wavelength of the microcavity emission peak of the second curve c2 (as described above, the length of the microcavity 20 is positively correlated with the wavelength of the emitted light).

[0059] At the same time, the brightness value corresponding to the microcavity emission peak of the third curve c3 is the same as the brightness value corresponding to the microcavity emission peak of the second curve c2 (both are initial brightness value L0); this is due to the luminescence characteristics of the material of the green light-emitting functional layer 142 itself, and the microcavity effect cannot make the brightness of the emitted light of the green light-emitting functional layer 142 exceed its inherent maximum brightness.

[0060] In the embodiment of the present application, the formula 2 for the blue shift of the luminescence spectrum due to the microcavity effect with the viewing angle is as follows:

[0061]

[0062] Among them, θ out is the angle between the viewing angle direction and the direction perpendicular to the green light emitting device, n is the refractive index of the material of the green light emitting functional layer 142, λ0 is the wavelength of the light emitted by the green light emitting functional layer 142 after being affected by the microcavity effect when the viewing angle is 0°, λ(θ out ) is the wavelength of the light emitted by the green light-emitting functional layer 142 after being affected by the microcavity effect at the current viewing angle.

[0063] From the above formula, we can see that as the viewing angle θ out As the wavelength of the light emitted by the green light-emitting functional layer 142 decreases after being affected by the microcavity effect, that is, the microcavity effect causes the light emission spectrum to blue-shift with viewing angle.

[0064] In the embodiment of the present application, in the light-emitting device group displaying green, the length of the microcavity 20 of each light-emitting device is greater than the resonant cavity length of the wavelength of the light of the color displayed by the light-emitting device group, and the resonant cavity length is the cavity length corresponding to the light-emitting device when the microcavity emission peak coincides with the intrinsic emission peak. At this time, the microcavity emission peak of the green light-emitting device is located on the right side of the intrinsic emission peak, such as Figure 1 As shown, the wavelength corresponding to the microcavity emission peak of the green light-emitting device is about 540 nm, while the wavelength corresponding to the intrinsic emission peak is about 520 nm, and the microcavity emission peak is located on the right side of the intrinsic emission peak.

[0065] When the viewing angle θ outWhen the green light emitting device starts to increase, the microcavity characteristic curve corresponding to the green light emitting device will change with the viewing angle θ out The green light emitting device is blue-shifted due to the increase of the green light emitting device, so that the microcavity characteristic curve corresponding to the green light emitting device is close to the intrinsic characteristic curve, thereby increasing the light emitting brightness of the light emitting device while avoiding the chromaticity shift of the light emitting device, further realizing the wide viewing angle display of the display panel 100.

[0066] Specifically, Figure 3 As shown, it is a brightness characteristic curve diagram of the green light-emitting functional layer 142 at different viewing angles in the first display panel 100 provided in an embodiment of the present application, wherein the horizontal axis is the wavelength (Wavelength, unit nm) and the vertical axis is the brightness value (unit nite).

[0067] Wherein, when the viewing angle θ out When the viewing angle θ is 0°, the wavelength corresponding to the microcavity emission peak of the green light-emitting device is about 540 nm. At this time, the brightness of the green light-emitting device is the brightness when the wavelength corresponds to 540 nm in the intrinsic characteristic curve. out When the viewing angle θ is 40°, the wavelength corresponding to the microcavity emission peak of the green light-emitting device is about 520 nm. At this time, the brightness of the green light-emitting device is the brightness when the wavelength corresponds to 520 nm in the intrinsic characteristic curve. At this time, the brightness of the green light-emitting device is the maximum. out When the angle is 70°, the wavelength corresponding to the microcavity emission peak of the green light-emitting device is about 512nm. At this time, the brightness of the green light-emitting device is the brightness when the wavelength corresponds to 512nm in the intrinsic characteristic curve. At this time, the brightness of the green light-emitting device is the minimum.

[0068] Therefore, when the viewing angle θ out When the viewing angle θ increases gradually from 0° to 70°, the wavelength corresponding to the microcavity emission peak of the green light-emitting device gradually decreases; wherein, the viewing angle θ out In the process of gradually increasing from 0° to 40°, the luminance value of the green light-emitting device gradually increases (the process of the microcavity emission peak approaching the intrinsic emission peak). At this time, increasing the cavity length of the plurality of light-emitting devices in at least one light-emitting device group in the display panel 100 can increase the brightness value as the viewing angle increases within a certain viewing angle range.

[0069] The viewing angle θ out In the process of gradually increasing from 40° to 70°, the luminous brightness value of the green light-emitting device gradually decreases (the process in which the microcavity emission peak moves away from the intrinsic emission peak).

[0070] Preferably, when the cavity length of the green light-emitting device is greater than the resonance cavity length of the green light wavelength, and the wavelength of the microcavity emission peak of the green light-emitting device is 540nm when the viewing angle is 0°, and the side viewing angle is 40°, the brightness value corresponding to the green light-emitting device is the largest.

[0071] Therefore, Figure 3 It can be seen that the peak wavelength of the light emitted by the organic light-emitting functional layer 14 at the first preset viewing angle is the first peak wavelength, and the peak wavelength of the light emitted by the organic light-emitting functional layer 14 at the second preset viewing angle is the second peak wavelength;

[0072] The second preset viewing angle is greater than the first preset viewing angle, and the second peak wavelength is smaller than the first peak wavelength.

[0073] Furthermore, within a preset viewing angle range (0° to 40°), the brightness value of the light emitted by the organic light-emitting functional layer 14 at the second preset viewing angle is greater than the brightness value of the light emitted by the organic light-emitting functional layer 14 at the first preset viewing angle.

[0074] Correspondingly, the embodiment of the present application can also adjust the thickness of the red light-emitting functional layer 141 so that the cavity length of the red light-emitting device is greater than the resonance cavity length of the red light wavelength, thereby making the microcavity emission peak of the red light-emitting functional layer 141 located to the right of the intrinsic emission peak of the red light-emitting functional layer 141, so as to achieve the control of the red light viewing angle.

[0075] Furthermore, the embodiment of the present application can also adjust the thickness of the blue light-emitting functional layer 143 so that the cavity length of the blue light-emitting device is greater than the resonance cavity length of the blue light wavelength, so that the microcavity emission peak of the blue light-emitting functional layer 143 is located to the right of the intrinsic emission peak of the blue light-emitting functional layer 143, so as to achieve the control of the blue light viewing angle.

[0076] Furthermore, since white light is achieved by regulating the luminous ratio of red sub-pixels, green sub-pixels and blue sub-pixels, a wide viewing angle of white light can be achieved by adjusting the cavity length of multiple light-emitting devices displaying the same color in any one of the light-emitting device groups.

[0077] like Figure 4 As shown, it is a schematic diagram of the relationship between the white light viewing angle and the brightness ratio at different cavity lengths of the first display panel 100 provided in an embodiment of the present application; wherein, the horizontal axis is the side viewing angle, and the vertical axis is the ratio of the white light real-time brightness L3 to the white light initial brightness L2, the initial brightness L2 is the brightness value corresponding to the white light emitted by the display panel 100 when the side viewing angle is 0°, and the white light real-time brightness L3 is the brightness value corresponding to the white light emitted by the display panel 100 at the current side viewing angle.

[0078] Specifically, the fourth curve is a relationship curve between the viewing angle and the brightness of the first type of display panel, and the fifth curve is a relationship curve between the viewing angle and the brightness of the second type of display panel; wherein, in the first type of display panel, the cavity length of the red light-emitting device is the resonance cavity length of the red light wavelength, the cavity length of the green light-emitting device is the resonance cavity length of the green light wavelength, and the cavity length of the blue light-emitting device is the resonance cavity length of the blue light; in the second type of display panel, in at least one of the light-emitting device groups, the length of the microcavity 20 of each of the light-emitting devices is greater than the resonance cavity length of the wavelength of light of the color displayed by the light-emitting device group.

[0079] Specifically, when the viewing angle gradually increases, the brightness values ​​of the first type of display panel and the second type of display panel gradually decrease, because the microcavity effect causes the emission curve of the microcavity 20 of the display panel 100 to lose brightness as the viewing angle increases. At the same time, when the viewing angle approaches 40°, the brightness value of the first type of display panel becomes 0, and at this time, the brightness ratio of the second type of display panel is between 0.7 and 0.8; when the viewing angle approaches 60°, the brightness value of the second type of display panel becomes 0.

[0080] Furthermore, when the viewing angle changes from approximately 40° to approximately 60°, the first type of display panel does not emit light, while the second type of display panel still emits light. Therefore, increasing the cavity length of the plurality of light emitting devices in at least one light emitting device group in the display panel 100 can achieve wide viewing angle display of white light.

[0081] In order to solve the problem that the light spectrum of the light-emitting device blue-shifts with increasing viewing angle due to the microcavity effect, the prior art increases the cavity length by reducing the thickness of the first electrode 13, and increases the transparency of the second electrode 15 to weaken the microcavity interference intensity. However, this method reduces the light-emitting efficiency and increases the electrode impedance, and the voltage drop (IRDrop) problem needs to be further solved. Another method is to use a transparent conductive oxide electrode TCO (transparent conductive film), which requires sputtering equipment to prepare and will cause a certain degree of damage to the organic material.

[0082] The display panel 100 of the embodiment of the present application can achieve wide-viewing angle display without changing the thickness of the first electrode 13 or the second electrode 15. It is mainly designed to adjust the cavity length of at least one monochromatic light-emitting device so that its microcavity emission peak is located on the right side of the intrinsic main emission peak. The brightness viewing angle and chromaticity viewing angle of white light can be adjusted by the different displacement amounts of the microcavity emission peak of the light-emitting device from the intrinsic main emission peak, thereby achieving the purpose of wide-viewing angle display.

[0083] In view of the technical problem that the chromaticity of an existing display panel 100 having a microcavity 20 structure shifts after changing the viewing angle, the embodiment of the present application provides a display panel 100 and a mobile terminal; the display panel 100 includes a first substrate 11 and a plurality of light-emitting devices arranged on the first substrate 11, the light-emitting devices include a first electrode 13 and a second electrode 15 arranged opposite to each other, and a microcavity 20 formed between the first electrode 13 and the second electrode 15, wherein the plurality of light-emitting devices displaying the same color form a light-emitting device group, and in at least one of the light-emitting device groups, the length of the microcavity 20 of each light-emitting device is greater than the length of the light-emitting device The display panel 100 makes the length of the microcavity 20 of each of the light-emitting devices in at least one of the light-emitting device groups greater than the resonant cavity length of the wavelength of the light of the color displayed by the light-emitting device group, so that the microcavity emission peak of the light-emitting device is offset from the intrinsic main emission peak and is located on the right side of the intrinsic main emission peak. When the viewing angle increases, the microcavity emission peak of the light-emitting device moves toward the direction close to the intrinsic main emission peak as the viewing angle increases, so as to minimize the blue shift of the spectrum at different viewing angles, thereby producing an effect of preventing color deviation, and further realizing the wide viewing angle display of the display panel 100.

[0084] Embodiment 2

[0085] like Figure 5 , which is a cross-sectional schematic diagram of a second display panel 100 provided in an embodiment of the present application; wherein the structure of the display panel 100 in the second embodiment of the present application is the same as or similar to the structure of the display panel 100 in the first embodiment of the present application, and the only difference is that the display panel 100 further includes a second substrate 110 disposed opposite to the first substrate 11 and a color filter film 18 disposed on the second substrate 110 and close to a side of the first substrate 11;

[0086] The transmission spectrum of the color filter film 18 matches the emission spectrum of the organic light-emitting functional layer 14 .

[0087] In the embodiment of the present application, the display panel 100 further includes an encapsulation layer 17, which is located between the color filter film 18 and the first substrate 11, and is disposed on the pixel definition layer 16 and the second electrode 15. The encapsulation layer 17 is used to block the intrusion of water and oxygen from the outside.

[0088] In the embodiment of the present application, the color filter film 18 includes a red color resist 181 , a green color resist 182 and a blue color resist 183 respectively arranged corresponding to the red light emitting functional layer 141 , the green light emitting functional layer 142 and the blue light emitting functional layer 143 ;

[0089] Among them, the absolute value of the difference between the peak transmittance wavelength of the red color resist 181 and the peak emission wavelength of the red light-emitting functional layer 141, the absolute value of the difference between the peak transmittance wavelength of the green color resist 182 and the peak emission wavelength of the green light-emitting functional layer 142, and the absolute value of the difference between the peak transmittance wavelength of the blue color resist 183 and the peak emission wavelength of the blue light-emitting functional layer 143 are all less than the preset difference.

[0090] Preferably, the absolute value of the preset difference is less than 2 nanometers.

[0091] Furthermore, the color filter film 18 further includes a black matrix layer 19. The black matrix layer 19 is disposed between adjacent color resists, and the black matrix layer 19 has the function of preventing light leakage of the display panel 100 and reducing reflection of the display panel 100. The color resist includes any one of the red color resist 181, the green color resist 182, and the blue color resist 183.

[0092] In the embodiment of the present application, due to the microcavity effect, the microcavity emission spectrum of the light-emitting device blue-shifts as the viewing angle increases; therefore, different color-resistance materials can be used to make the transmission spectra of color-resistance materials of different luminescent colors different, that is, by adjusting the position of the transmission starting peak and the position of the transmission cutoff peak of the transmission spectrum, the transmission spectrum of the color filter film 18 at different viewing angles is matched with the emission spectrum of the organic light-emitting functional layer 14, thereby realizing the regulation of the white light viewing angle, and then realizing the wide-viewing angle display of the display panel 100.

[0093] In view of the technical problem that the chromaticity shifts after the viewing angle is changed in the existing display panel 100 with a microcavity 20 structure, the embodiment of the present application provides a display panel 100, which includes a first substrate 11 and a plurality of light-emitting devices arranged on the first substrate 11, wherein the light-emitting devices include a first electrode 13 and a second electrode 15 arranged opposite to each other, and a microcavity 20 formed between the first electrode 13 and the second electrode 15, wherein the plurality of light-emitting devices displaying the same color form a light-emitting device group, and in at least one of the light-emitting device groups, the length of the microcavity 20 of each light-emitting device is greater than the length of the microcavity 20 displayed by the light-emitting device group. The above-mentioned display panel 100 makes the length of the microcavity 20 of each light-emitting device in at least one of the light-emitting device groups greater than the resonant cavity length of the wavelength of the light of the color displayed by the light-emitting device group, so that the microcavity emission peak of the light-emitting device is offset from the intrinsic main emission peak and is located on the right side of the intrinsic main emission peak. When the viewing angle increases, the microcavity emission peak of the light-emitting device moves toward the intrinsic main emission peak as the viewing angle increases, so as to minimize the blue shift of the spectrum at different viewing angles, thereby producing the effect of preventing color deviation, and further realizing the wide viewing angle display of the display panel 100. At the same time, compared with the first embodiment of the present application, the second embodiment of the present application can also realize the regulation of the white light viewing angle by increasing the matching of the transmission spectrum of the color filter film 18 to achieve a wide viewing angle.

[0094] Accordingly, the embodiment of the present application further provides a mobile terminal, comprising a terminal body and a display panel 100 as described in any one of the above items, wherein the terminal body and the display panel 100 are integrated into one. The mobile terminal has a wide range of applications in vehicle-mounted, mobile phones, tablets, computers and television products.

[0095] The display panel 100 and the mobile terminal provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A display panel, characterized in that: The invention comprises a first substrate and a plurality of light-emitting devices arranged on the first substrate, wherein the light-emitting devices comprise a first electrode and a second electrode arranged opposite to each other, and a microcavity formed between the first electrode and the second electrode; The plurality of light-emitting devices include a plurality of light-emitting device groups for displaying different light-emitting colors, and each of the light-emitting device groups includes a plurality of light-emitting devices displaying the same color; in at least one of the light-emitting device groups, the length of the microcavity of each of the light-emitting devices is greater than the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group; the display panel further includes an organic light-emitting functional layer disposed in the microcavity, and when the length of the microcavity of the light-emitting device is equal to the resonant cavity length of the wavelength of light of the color displayed by the light-emitting device group, the thickness of the organic light-emitting functional layer in the light-emitting device is a first thickness; In at least one of the light-emitting device groups, the thickness of the organic light-emitting functional layer in each of the light-emitting devices is greater than the first thickness; the organic light-emitting functional layer includes any one of a red light-emitting functional layer, a green light-emitting functional layer and a blue light-emitting functional layer; the thickness of the red light-emitting functional layer is greater than the thickness of the green light-emitting functional layer, and the thickness of the green light-emitting functional layer is greater than the thickness of the blue light-emitting functional layer.

2. The display panel according to claim 1, characterized in that: The peak wavelength of the light emitted by the organic light-emitting functional layer at the first preset viewing angle is a first peak wavelength, and the peak wavelength of the light emitted by the organic light-emitting functional layer at the second preset viewing angle is a second peak wavelength; The second preset viewing angle is greater than the first preset viewing angle, and the second peak wavelength is smaller than the first peak wavelength.

3. The display panel according to claim 2, characterized in that: When the first preset viewing angle and the second preset viewing angle are both within a preset viewing angle range, the brightness value of the light emitted by the organic light-emitting functional layer at the second preset viewing angle is greater than the brightness value of the light emitted by the organic light-emitting functional layer at the first preset viewing angle.

4. The display panel according to claim 1, characterized in that: The red light-emitting functional layer, the green light-emitting functional layer and the blue light-emitting functional layer each include a hole injection layer disposed on the first electrode, a hole transport layer disposed on the hole injection layer, a light-emitting layer disposed on the hole transport layer, an electron transport layer disposed on the light-emitting layer, and an electron injection layer disposed on the electron transport layer; Among them, the thickness of the hole transport layer corresponding to the red light-emitting functional layer is greater than the thickness of the hole transport layer corresponding to the green light-emitting functional layer, and the thickness of the hole transport layer corresponding to the green light-emitting functional layer is greater than the thickness of the hole transport layer corresponding to the blue light-emitting functional layer.

5. The display panel according to claim 1, characterized in that: The display panel further includes a second substrate disposed opposite to the first substrate and a color filter film disposed on the second substrate and close to a side of the first substrate; Wherein, the transmission spectrum of the color filter film matches the emission spectrum of the organic light-emitting functional layer.

6. The display panel according to claim 5, characterized in that: The color filter film includes a red color resist, a green color resist and a blue color resist respectively arranged corresponding to the red light emitting functional layer, the green light emitting functional layer and the blue light emitting functional layer; Among them, the absolute value of the difference between the peak transmittance wavelength of the red color resist and the peak emission wavelength of the red light-emitting functional layer, the absolute value of the difference between the peak transmittance wavelength of the green color resist and the peak emission wavelength of the green light-emitting functional layer, and the absolute value of the difference between the peak transmittance wavelength of the blue color resist and the peak emission wavelength of the blue light-emitting functional layer are all less than the preset difference.

7. The display panel according to claim 1, characterized in that: The reflectivity of the first electrode is greater than that of the second electrode, and the transmittance of the first electrode is less than that of the second electrode.

8. A mobile terminal, characterized in that: The invention comprises a terminal body and a display panel as claimed in any one of claims 1 to 7, wherein the terminal body and the display panel are integrated into one body.

Images