Display panel and display device

Abstract

The application discloses a display panel and a display device, and relates to the technical field of display. The display panel comprises an array layer and a plurality of light emitting elements located on one side of the array layer; the array layer comprises at least a driving layer and a reflecting layer, and the reflecting layer is located between the driving layer and the light emitting elements; the reflecting layer comprises a first planarization layer and a second planarization layer, and the first planarization layer is located on one side of the second planarization layer close to the light emitting elements; and the first planarization layer and the second planarization layer constitute a first Bragg reflection structure. The embodiment provided by the application can improve the brightness of the display panel, and can also avoid the influence of light rays pointing to the array layer on driving devices located on the driving layer, thereby improving the display effect.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more specifically, to a display panel and a display device. Background Technology

[0002] Micro LED display technology refers to a display technology that uses self-emissive, micrometer-sized LEDs as light-emitting pixel units, assembling them onto a driving panel to form a high-density LED array. Due to the small size, high integration, and self-emissive nature of Micro LED chips, they offer significant advantages over LCD and OLED displays in terms of brightness, resolution, contrast ratio, energy consumption, lifespan, response speed, and thermal stability.

[0003] In related technologies, light emitted by light-emitting elements is directed in various directions. Light directed outwards from the display panel is used for normal display, while light directed inwards illuminates the active layer of the display panel. Light illuminating the active layer not only results in low light extraction efficiency of the display panel but also causes leakage current in the TFT (Thin Film Transistor) and Vth offset, leading to display abnormalities and affecting display performance. Summary of the Invention

[0004] In view of this, the present invention provides a display panel and display device that can reduce the impact of light on thin-film transistors and improve the display effect.

[0005] In a first aspect, the present invention provides a display panel, comprising: an array layer and a plurality of light-emitting elements located on one side of the array layer;

[0006] The array layer includes at least a driving layer and a reflective layer, with the reflective layer located between the driving layer and the light-emitting element;

[0007] The reflective layer includes a first planarization layer and a second planarization layer, wherein the first planarization layer is located on the side of the second planarization layer closer to the light-emitting element;

[0008] The first planarization layer and the second planarization layer constitute the first Bragg reflection structure.

[0009] In a second aspect, the present invention provides a display device including the display panel provided in the first aspect of the present invention.

[0010] Compared with the prior art, the display panel and display device provided by the present invention achieve at least the following beneficial effects:

[0011] The display panel provided by this invention has a reflective layer disposed between the driving layer and the light-emitting element. The reflective layer includes a first planarization layer and a second planarization layer that can form a first Bragg reflection structure. The first and second planarization layers not only meet the requirement of forming a relatively flat reference surface on the driving layer for arranging the light-emitting element, but also enable total internal reflection of the light emitted by the light-emitting element pointing towards the array layer. The first Bragg reflection structure can reflect the light emitted by the light-emitting element back, which not only improves the brightness of the display panel, but also prevents the light pointing towards the array layer from affecting the driving device located on the driving layer, thereby improving the display effect.

[0012] Of course, any product implementing this invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0013] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0014] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0015] Figure 1 This is a top view of a display panel provided in an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the cross-sectional structure of a display panel along AA provided in an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of a cross-sectional structure along AA of another display panel provided in an embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of a cross-sectional structure along AA of another display panel provided in an embodiment of the present invention;

[0019] Figure 5 This is a schematic diagram of a cross-sectional structure along AA of another display panel provided in an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of a cross-sectional structure along AA of another display panel provided in an embodiment of the present invention;

[0021] Figure 7 This is a schematic diagram of a cross-sectional structure along AA of another display panel provided in an embodiment of the present invention;

[0022] Figure 8 This is a top view of a display device provided in an embodiment of the present invention;

[0023] Figure 9 This is a schematic cross-sectional view of a display device along BB, provided in an embodiment of the present invention. Detailed Implementation

[0024] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0025] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0026] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0027] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0029] In related technologies, light from light-emitting elements is emitted in various directions. Light directed outwards from the display panel is used for display purposes, while light directed inwards may illuminate the active layer of the display panel. This not only results in low light extraction efficiency of the display panel but also causes leakage current in the TFT (Thin Film Transistor) and Vth offset, leading to display abnormalities and affecting the display effect.

[0030] To address the aforementioned technical problems, embodiments of the present invention provide a display panel, as shown below. Figure 1 and Figure 2 As shown, where, Figure 1 This is a top view of a display panel provided in an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of a display panel along line AA provided in an embodiment of the present invention. The embodiment of the present invention provides a display panel including an array layer 01 and a plurality of light-emitting elements 10 located on one side of the array layer 01;

[0031] The array layer 01 includes at least a driving layer 011 and a reflective layer 012, with the reflective layer 012 located between the driving layer 011 and the light-emitting element 10.

[0032] The reflective layer 012 includes a first planarization layer PLN1 and a second planarization layer PLN2, with the first planarization layer PLN1 located on the side of the second planarization layer PLN2 closer to the light-emitting element 10.

[0033] The first planarization layer PLN1 and the second planarization layer PLN2 constitute the first Bragg reflection structure DBR1.

[0034] It is understood that the display panel includes an array layer 01 and multiple light-emitting elements 10. The array layer 01 is located on one side of the substrate 00 and is used to arrange driving circuits. The array layer 01 is electrically connected to the light-emitting elements 10 to drive the light-emitting elements 10 to emit light. In the embodiments provided by the present invention, the light-emitting element 10 can be a Micro LED, OLED, etc. For example, MicroLED is a micrometer-scale self-emissive element, which can be fabricated on a display panel to form a high-density LED display panel, improving the brightness, resolution, and other performance of the display panel. It should be noted that the type of light-emitting element 10 is not limited to the above examples, and any element capable of self-emission can be used as the light-emitting element 10 of the present invention.

[0035] Furthermore, the array layer 01 includes at least a driving layer 011 and a reflective layer 012. The reflective layer 012 is located between the driving layer 011 and the light-emitting element 10. In other words, along the first direction x, the light-emitting element 10, the reflective layer 012, and the driving layer 011 are arranged sequentially. The first direction x refers to the direction in which the light-emitting element 10 points towards the array layer 01. The reflective layer 012 includes a first planarization layer PLN1 and a second planarization layer PLN2, with the first planarization layer PLN1 located on the side of the second planarization layer PLN2 closer to the light-emitting element 10. By placing the first planarization layer PLN1 and the second planarization layer PLN2 between the driving layer 011 and the light-emitting element 10, on the one hand, the film thickness can be increased through the first planarization layer PLN1 and the second planarization layer PLN2, reducing parasitic capacitance. On the other hand, the driving layer 011 has multiple film layers. Due to the possible presence of metal traces or driving devices in different film layers, the thickness of the driving layer 011 is uneven at different locations. By providing a first planarization layer PLN1 and a second planarization layer PLN2 between the driving layer 011 and the light-emitting element 10, the side of the array layer 01 closest to the light-emitting element 10 can have a relatively flat surface for arranging the light-emitting element 10. For example, when the light-emitting element 10 is a Micro LED, the flat reflective layer 012 facilitates the transfer of the Micro LED; when the light-emitting element is an OLED, the flat reflective layer 012 facilitates the fabrication of the anode and prevents anode breakage due to surface unevenness.

[0036] Furthermore, the first planarization layer PLN1 and the second planarization layer PLN2 constitute the first Bragg reflection structure DBR1. It is understood that, in order to improve the display effect, the light emitted by the light-emitting element 10 should be emitted as far away from the array layer 01 as possible; for example, refer to... Figure 2 As shown, light L1 is emitted away from array layer 01, and light L1 can be used for image display. However, the light emitted by the light-emitting element 10 is directed in various directions, for example, Figure 2 The light ray L2, which points towards array layer 01, not only cannot be used for image display and affects the brightness of the display panel, but also affects the driving devices on array layer 01. It should be noted that the accompanying drawings provided in this embodiment are only for illustrating the direction of light and do not represent the actual optical path.

[0037] Specifically, refer to Figure 3 As shown, Figure 3 This is a schematic cross-sectional view of another display panel provided in an embodiment of the present invention along line AA. The driving layer 011 includes a driving device, which, in the embodiment provided by the present invention, includes a thin-film transistor (TFT) M. The driving circuit controls the light-emitting element 10 to emit light or not, and the brightness of the light-emitting element 10, by controlling the signal of the TFT M. Along the first direction x, the portion of the active layer 0111 of the TFT M that overlaps with the gate G forms a channel region N. When illuminated, the channel region N forms photogenerated carriers, i.e., electron-hole pairs: electrons move towards the drain, and holes move towards the source, thereby forming a leakage current, affecting the light-emitting effect of the display panel. Therefore, the first planarization layer PLN1 and the second planarization layer PLN2 located between the light-emitting element 10 and the driving layer 011 constitute a first Bragg reflection structure DBR1. The first Bragg reflection structure DBR1 can reflect light pointing towards the array layer 01. For example, refer to... Figure 2 As shown, the light L2 pointing towards array layer 01 is reflected by the first Bragg reflector structure DBR1, forming a light L3 that is away from array layer 01. Light L3 can be used for screen display, which not only improves the brightness of the display panel, but also prevents the light from affecting the driving devices on array layer 01.

[0038] In one optional embodiment provided by the present invention, the refractive index n2 of the second planarization layer PLN2 is less than the refractive index n1 of the first planarization layer PLN1.

[0039] It is understood that the second planarization layer PLN2 is located on the side of the first planarization layer PLN1 away from the light-emitting element 10. Light emitted from the light-emitting element 10, pointing towards the array layer 01, passes sequentially through the first planarization layer PLN1 and the second planarization layer PLN2. In the embodiment provided by this invention, the refractive index n2 of the second planarization layer PLN2 is less than the refractive index n1 of the first planarization layer PLN1. In other words, compared to the second planarization layer PLN2, the first planarization layer PLN1 is an optically denser medium, and the second planarization layer PLN2 is an optically less dense medium. When light emitted from the light-emitting element 10 travels from the optically denser medium to the optically less dense medium, total internal reflection occurs at the interface between the optically denser and optically less dense media, that is, at the interface between the first planarization layer PLN1 and the second planarization layer PLN2. In this way, the light emitted by the light-emitting element 10 that is directed towards the array layer 01 is reflected. This not only makes full use of the light emitted by the light-emitting element 10 to improve the brightness of the display panel, but also prevents the light emitted by the light-emitting element 10 from shining on the driving device located in the driving layer 011, thus avoiding any impact on the driving device and consequently affecting the display effect.

[0040] Furthermore, the refractive index n1 of the first planarization layer PLN1 and the refractive index n2 of the second planarization layer PLN2 are determined by the materials of the first planarization layer PLN1 and the second planarization layer PLN2 themselves. Specifically, the material of the first planarization layer PLN1 can be TiO2, Ta2O5, HfO2, Ti3O5, Nb2O5, etc. The material of the second planarization layer PLN2 can be SiO2, SiN... x Materials such as Al2O3 and MgF are used. The refractive index n1 of the first planarization layer PLN1 is greater than the refractive index n2 of the second planarization layer PLN2, and the greater the difference between the refractive indices n1 and n2 of the first and second planarization layers PLN1, the better the reflection effect of the first Bragg reflection structure DBR1. For example, when TiO2 is used for the first planarization layer PLN1 and SiO2 is used for the second planarization layer PLN2, the refractive index of TiO2 is 2.5, and the refractive index of SiO2 is 1.5. TiO2 is optically denser and SiO2 is optically less dense. When light travels from TiO2 to SiO2, total internal reflection occurs at the interface between TiO2 and SiO2.

[0041] It should be noted that in the embodiments provided by the present invention, the refractive index n1 of the first planarization layer PLN1, the refractive index n2 of the second planarization layer PLN2 and their difference are not specifically limited. The corresponding materials can be selected according to the actual application scenario, as long as the refractive index n1 of the first planarization layer PLN1 is greater than the refractive index n2 of the second planarization layer PLN2.

[0042] In one optional embodiment provided by the present invention, the thickness of the first planarization layer PLN1 is N1λ / 4; and the thickness of the second planarization layer PLN2 is N2λ / 4.

[0043] Where N1 and N2 are both positive integers; λ is the wavelength of the light-emitting color of the light-emitting element 10.

[0044] It is understood that, in the embodiments provided by this invention, when light shines on the first planarization layer PLN1, reflection occurs at both the interface of the first planarization layer PLN1 near the light-emitting element 10 and the interface of the first planarization layer PLN1 away from the light-emitting element 10. Since the thickness of the first planarization layer PLN1 is N1λ / 4, where N1 is a positive integer and λ is the wavelength of the light emitted by the light-emitting element 10, the light reflected from the interface of the first planarization layer PLN1 away from the light-emitting element 10 will overlap with the light reflected from the interface of the first planarization layer PLN1 near the light-emitting element 10. Specifically, the peaks and troughs of the two beams of light overlap, thus enhancing the reflection effect.

[0045] Similarly, the thickness of the second planarization layer PLN2 is N2λ / 4, where N2 is a positive integer; λ is the wavelength of the emitted color of the light-emitting element 10. The light reflected from the interfaces of the second planarization layer PLN2 near and far from the light-emitting element 10 will overlap, enhancing the reflection effect. In other words, the light emitted by the light-emitting element 10 pointing towards the array layer 01 will achieve a reflection enhancement effect in both the first planarization layer PLN1 and the second planarization layer PLN2. This improves the brightness of the display panel, enhances the display effect, and at the same time, avoids the influence of light on the driving devices of the driving layer 011, improving the stability of the display.

[0046] It should be noted that the thicknesses of the first planarization layer PLN1 and the second planarization layer PLN2 are not fixed and can vary depending on the values ​​of N1 and N2. N1 and N2 are both positive integers, and for example, they can be 1, 2, 3, 5, 10, etc. Since the first Bragg reflector structure DBR1 not only serves as a reflector but also provides a relatively flat reference surface, the thicknesses of the first planarization layer PLN1 and the second planarization layer PLN2 do not necessarily have to be λ / 4; they can vary in integer multiples depending on the actual application scenario. At the same time, the thicknesses of the first planarization layer PLN1 and the second planarization layer PLN2 do not necessarily have to be the same, that is, N1 and N2 do not necessarily have to be identical. For example, the thickness of the first planarization layer PLN1 can be λ / 4, and the thickness of the second planarization layer PLN2 can be 3λ / 4. However, it should be noted that λ in the thicknesses of the first and second planarization layers PLN1 and PLN2 must be the same value. In other words, the first Bragg reflector structure DBR1, or the light-emitting element 10 corresponding to its first planarization layer PLN1 and second planarization layer PLN2, emits only one color. Of course, the light-emitting element 10 can emit only one or multiple colors. When the light-emitting element 10 emits only one color, the thickness of the first planarization layer PLN1 and second planarization layer PLN2 in the first Bragg reflector structure DBR1 is adapted to the wavelength of that emitted color. When the light-emitting element 10 emits multiple colors, the thickness of the first planarization layer PLN1 and second planarization layer PLN2 in the first Bragg reflector structure DBR1 can be adapted to the wavelength of any one of the multiple emitted colors. In practical applications, the thickness of the first planarization layer PLN1 and second planarization layer PLN2 in the first Bragg reflector structure DBR1 can be adapted to the wavelength of the most predominant emitted color in the light-emitting element 10, or it can be adapted to the wavelength of an emitted color with lower luminous efficiency in the light-emitting element 10; this will not be elaborated further here.

[0047] In one optional embodiment provided by the present invention, reference continues to... Figure 3 As shown, the driving layer 011 is provided with a thin-film transistor M;

[0048] The source or drain of the thin-film transistor M is connected to the light-emitting element 10 through a via K.

[0049] It is understood that, in the embodiments provided by the present invention, the driving device may include a thin-film transistor M. The thin-film transistor M is located in the driving layer 011 and is electrically connected to the light-emitting element 10 to drive the light-emitting element 10 to emit light.

[0050] Furthermore, since a reflective layer 012 is provided between the driving layer 011 and the light-emitting element 10, the embodiment provided by the present invention includes a via K. One end of the via K is electrically connected to the light-emitting element 10, and the other end of the via K passes through the first planarization layer PLN1 and the second planarization layer PLN2 and is electrically connected to the source or drain of the thin-film transistor M. Conductive material is deposited inside the via K, thus enabling the electrical connection between the thin-film transistor M and the light-emitting element 10.

[0051] It should be noted that after fabricating the thin-film transistor M, the side of the driving layer 011 near the light-emitting element 10 is uneven. Therefore, a second planarization layer PLN2 is formed on the side of the driving layer 011 near the light-emitting element 10, and the side of the second planarization layer PLN2 near the light-emitting element 10 forms a flat surface. Since the side of the driving layer 011 near the light-emitting element 10 is uneven, the thickness of the second planarization layer PLN2 along the first direction x is not uniform. For example, the thickness of the second planarization layer PLN2 located on the side of the source and / or drain of the thin-film transistor M near the light-emitting element 10 is less than the thickness of other parts of the second planarization layer PLN2. The via K only needs to pass through the reflective layer 012 between the light-emitting element 10 and the thin-film transistor M, and the electrical connection between the thin-film transistor M and the light-emitting element 10 is achieved through the conductive material in the via K.

[0052] Optionally, the driving layer 011 includes multiple film layers, and the thin-film transistor M is also located on multiple film layers of the driving layer 011. One end of the source and drain of the thin-film transistor M can be located on the side of the driving layer 011 along the first direction x, close to the light-emitting element 10. A second planarization layer PLN2 is formed on the source and drain of the thin-film transistor M, so that the source and drain of the thin-film transistor M form relatively flat surfaces. The thickness of the second planarization layer PLN2 satisfies N2λ / 4, where N2 is a positive integer; λ is the wavelength of the emission color of the light-emitting element 10. Then, a first planarization layer PLN1 is formed on the second planarization layer PLN2. The thickness of the second planarization layer PLN2 satisfies N1λ / 4, where N1 is a positive integer; λ is the wavelength of the emission color of the light-emitting element 10, and vias K are formed at corresponding positions in the first planarization layer PLN1. The two ends of the vias K are respectively connected to the light-emitting element 10 and the source or drain of the thin-film transistor M.

[0053] The embodiments provided by the present invention enable the thin film transistor M to drive the light-emitting element 10 by setting a thin film transistor M in the driving layer 011 and by setting a via K through the reflective layer located between the driving layer 011 and the light-emitting element 10, thereby completing the display function.

[0054] In one optional embodiment provided by the present invention, reference continues to... Figure 3As shown, the light-emitting element 10 includes a first electrode 11 and a second electrode 12. The first electrode 11 is connected to the source or drain of the thin-film transistor M through a via K, and the second electrode 12 is connected to a common electrode layer.

[0055] It is understood that the light-emitting element 10 includes a first electrode 11, a second electrode 12, and a light-emitting body 13. Both the first electrode 11 and the second electrode 12 are connected to the light-emitting body 13 and receive a driving signal and a ground signal / common signal, respectively. The light-emitting body 13 emits light through the voltage difference between the driving signal and the ground signal / common signal. In the embodiments provided by this invention, the first electrode 11 of the light-emitting element 10 is electrically connected to the source or drain of the thin-film transistor M through a via K, receiving the driving signal from the thin-film transistor M. The second electrode 12 of the light-emitting element 10 is electrically connected to the common electrode layer (not shown in the figure). It should be noted that in the embodiments provided by this invention, the light-emitting colors of the multiple light-emitting elements 10 can be the same color or different colors. For example, the light-emitting colors of the multiple light-emitting elements 10 can all be red. Alternatively, the light-emitting colors of the multiple light-emitting elements 10 can be one of red, green, and blue, respectively. Red, green, and blue can be mixed with different brightness levels to form different colors.

[0056] It should be noted that, referring to Figure 3 As shown, the first electrode 11 and the second electrode 12 can be disposed on the same side. Alternatively, the first electrode 11 and the second electrode 12 can be disposed on opposite sides. Specifically, "disposable on the same side" means that the first electrode 11 and the second electrode 12 are located on the same side of the light-emitting body 13; "disposable on opposite sides" means that the first electrode 11 and the second electrode 12 are located on different sides of the light-emitting body 13. The embodiments provided in this invention are not specifically limited, as long as the first electrode 11 can be connected to the source or drain of the thin-film transistor M through the via K, and the second electrode 12 can be connected to the common electrode layer.

[0057] In one optional embodiment provided by the present invention, refer to Figure 4 and Figure 5 As shown, where, Figure 4 This is a schematic diagram of a cross-sectional structure along AA of another display panel provided in an embodiment of the present invention. Figure 5 This is a schematic cross-sectional view of another display panel provided in an embodiment of the present invention along line AA. The reflective layer 012 further includes a third planarization layer PLN3 and a fourth planarization layer PLN4;

[0058] The third planarization layer PLN3 is located on the side of the fourth planarization layer PLN4 closest to the light-emitting element 10;

[0059] The fourth planarization layer PLN4 is located on the side of the first planarization layer PLN1 that is close to the light-emitting element 10;

[0060] The light-emitting element 10 includes at least a first light-emitting element 101 and a second light-emitting element 102, wherein the light-emitting color of the first light-emitting element 101 is different from the light-emitting color of the second light-emitting element 102;

[0061] The third planarization layer PLN3 and the fourth planarization layer PLN4 constitute the second Bragg reflection structure DBR2.

[0062] It is understood that in the embodiments provided by the present invention, the light-emitting element 10 includes at least a first light-emitting element 101 and a second light-emitting element 102, and the first light-emitting element 101 and the second light-emitting element 102 emit different colors. As can be seen from the above embodiments, different colors of light have different wavelengths. Therefore, in the embodiments provided by the present invention, the light-emitting element 10 includes a first light-emitting element 101 and a second light-emitting element 102 with different emission colors, and the Bragg reflection structure has a first Bragg reflection structure DBR1 and a second Bragg reflection structure DBR2.

[0063] Specifically, along the first direction x, the second Bragg reflector structure DBR2 is located on the side of the first Bragg reflector structure DBR1 closest to the light-emitting element 10. The second Bragg reflector structure DBR2 includes a third planarization layer PLN3 and a fourth planarization layer PLN4. The third planarization layer PLN3 is located on the side of the fourth planarization layer PLN4 closest to the light-emitting element 10. In other words, along the first direction x, the third planarization layer PLN3, the fourth planarization layer PLN4, the first planarization layer PLN1, and the second planarization layer PLN2 are sequentially stacked.

[0064] As can be seen from the above embodiments, the Bragg reflection structure can reflect the light emitted by the light-emitting element 10 that is directed towards the array layer 01 back. In the embodiments provided by the present invention, the first Bragg reflection structure DBR1 and the second Bragg reflection structure DBR2 are used to reflect light of different colors, that is, different wavelengths, to improve the brightness of the display panel and prevent the light from affecting the driving devices on the array layer 01.

[0065] It should be noted that, along the first direction x, the second Bragg reflector structure DBR2 is located on the side of the first Bragg reflector structure DBR1 closer to the light-emitting element 10. However, the embodiments provided by this invention do not specifically limit the light-emitting element 10 corresponding to the first Bragg reflector structure DBR1 and the second Bragg reflector structure DBR2. In one embodiment, the first Bragg reflector structure DBR1 corresponds to the emission color of the first light-emitting element 101, and the second Bragg reflector structure DBR2 corresponds to the emission color of the second light-emitting element 102. In another embodiment, the first Bragg reflector structure DBR1 corresponds to the emission color of the second light-emitting element 102, and the second Bragg reflector structure DBR2 corresponds to the emission color of the first light-emitting element 101.

[0066] Furthermore, referring to Figure 5 The thin-film transistors M disposed on the driving layer 011 include a first thin-film transistor M1 and a second thin-film transistor M2. The source or drain of the first thin-film transistor M1 is connected to the first light-emitting element 101 through a via K1 penetrating the reflective layer 012, and the source or drain of the second thin-film transistor M2 is connected to the first light-emitting element 102 through a via K2 penetrating the reflective layer 012. It should be noted that both the first thin-film transistor M1 and the second thin-film transistor M2 are located in the driving layer 011. In the embodiment provided by this invention, the reflective layer 012 includes a first Bragg reflection structure DBR1 and a second Bragg reflection structure DBR2. Both the first via K1 and the second via K2 need to penetrate the Bragg reflection structure DBR1 and the second Bragg reflection structure DBR2 to electrically connect the first thin-film transistor M1 and the first light-emitting element 101, or to electrically connect the second thin-film transistor M2 and the second light-emitting element 102.

[0067] In one optional embodiment provided by the present invention, the refractive index n4 of the fourth planarization layer PLN4 is less than the refractive index n3 of the third planarization layer PLN3.

[0068] It is understandable that the second Bragg reflector structure DBR2 satisfies the condition that the refractive index n4 of the fourth planarization layer PLN4 is less than the refractive index n3 of the third planarization layer PLN3. For example, if the first Bragg reflector structure DBR1 corresponds to the emission color of the first light-emitting element 101, and the second Bragg reflector structure DBR2 corresponds to the emission color of the second light-emitting element 102, then the light emitted by the second light-emitting element 102 pointing towards the array layer 01 passes sequentially through the third planarization layer PLN3 and the fourth planarization layer PLN4, i.e., when incident from an optically denser medium to an optically less dense medium, total internal reflection occurs at the interface between the third planarization layer PLN3 and the fourth planarization layer PLN4. Similarly, the light emitted by the first light-emitting element 101 pointing towards the array layer 01 passes sequentially through the first planarization layer PLN1 and the second planarization layer PLN2, i.e., when incident from an optically denser medium to an optically less dense medium, total internal reflection occurs at the interface between the first planarization layer PLN1 and the second planarization layer PLN2. Thus, when the light-emitting element 10 includes a first light-emitting element 101 and a second light-emitting element 102 with different emitting colors, the light emitted by the first light-emitting element 101 and the second light-emitting element 102 pointing towards the array layer 01 can be reflected by the reflective layer 012. This not only makes full use of the light emitted by the light-emitting element 10 to improve the brightness of the display panel, but also prevents the light emitted by the light-emitting element 10 from shining on the driving device located in the driving layer 011, thus avoiding affecting the driving device and consequently the display effect.

[0069] Furthermore, the refractive index n3 of the third planarization layer PLN3 and the refractive index n4 of the fourth planarization layer PLN4 are also determined by the materials of the third planarization layer PLN3 and the fourth planarization layer PLN4 themselves. Specifically, the material of the third planarization layer PLN3 can be TiO2, Ta2O5, HfO2, Ti3O5, Nb2O5, etc. The material of the fourth planarization layer PLN4 can be SiO2, SiN... x Al2O3, MgF, etc.

[0070] In one alternative embodiment provided by the present invention, the thickness of the first Bragg reflector structure DBR1 and the thickness of the second Bragg reflector structure DBR2 are different along the first direction x.

[0071] It is understood that the second Bragg reflector structure DBR2 includes a third planarization layer PLN3 and a fourth planarization layer PLN4. The thicknesses of the third planarization layer PLN3 and the fourth planarization layer PLN4 are N3λ / 4 and N4λ / 4, respectively. Here, N3 and N4 are both positive integers; λ is the wavelength of the emitted color of the light-emitting element 10.

[0072] For example, when the first Bragg reflection structure DBR1 corresponds to the emission color of the first light-emitting element 101, and the second Bragg reflection structure DBR2 corresponds to the emission color of the second light-emitting element 102, the wavelength of the emission color of the first light-emitting element 101 is λ1, and the wavelength of the emission color of the second light-emitting element 102 is λ2. Then, the thickness of the first Bragg reflection structure DBR1 is the sum of the thicknesses of the first planarization layer PLN1 and the first planarization layer PLN2, which is N1λ1 / 4 + N2λ1 / 4, where N1 and N2 are both positive integers. The thickness of the second Bragg reflection structure DBR2 is the sum of the thicknesses of the third planarization layer PLN3 and the fourth planarization layer PLN4, which is N3λ2 / 4 + N4λ2 / 4, where N3 and N4 are both positive integers. Mathematically, N1λ1 / 4 + N2λ1 / 4 can be equal to N3λ2 / 4 + N4λ2 / 4. However, in practical applications, to achieve a thinner and lighter design, N1λ1 / 4 + N2λ1 / 4 is usually not equal to N3λ2 / 4 + N4λ2 / 4. In other words, the thickness of the first Bragg reflector structure DBR1 is different from the thickness of the second Bragg reflector structure DBR2. This ensures that both the different colors of light emitted by the first light-emitting element 101 and the second light-emitting element 102 are reflected, improving the brightness of the display panel and preventing the light emitted by the light-emitting element 10 from shining on the driving device located in the driving layer 011, thus avoiding damage to the driving device. It also enables a thinner and lighter display panel design.

[0073] In one optional embodiment provided by the present invention, refer to Figure 6 and Figure 7 As shown, where, Figure 6 This is a schematic diagram of a cross-sectional structure along AA of another display panel provided in an embodiment of the present invention. Figure 7 This is a schematic cross-sectional view of another display panel provided in an embodiment of the present invention along line AA. The reflective layer 012 further includes a fifth planarization layer PLN5 and a sixth planarization layer PLN6;

[0074] The fifth planarization layer PLN5 is located on the side of the sixth planarization layer PLN6 closest to the light-emitting element 10;

[0075] The sixth planarization layer PLN6 is located on the side of the third planarization layer PLN3 that is close to the light-emitting element 10;

[0076] The light-emitting element 10 also includes a third light-emitting element 103; the first light-emitting element 101, the second light-emitting element 102, and the third light-emitting element 103 emit different colors;

[0077] The fifth planarization layer PLN5 and the sixth planarization layer PLN6 constitute the third Bragg reflection structure DBR3.

[0078] It is understood that in the embodiments provided by the present invention, the light-emitting element 10 includes at least a first light-emitting element 101, a second light-emitting element 102, and a third light-emitting element 103, and the first light-emitting element 101, the second light-emitting element 102, and the third light-emitting element 103 emit different colors. As can be seen from the above embodiments, different colors of light have different wavelengths. Therefore, in the embodiments provided by the present invention, the Bragg reflection structure has a first Bragg reflection structure DBR1, a second Bragg reflection structure DBR2, and a third Bragg reflection structure DBR3.

[0079] Specifically, along the first direction x, the second Bragg reflector structure DBR2 is located on the side of the first Bragg reflector structure DBR1 closest to the light-emitting element 10, and the third Bragg reflector structure DBR3 is located on the side of the second Bragg reflector structure DBR2 closest to the light-emitting element 10. The third Bragg reflector structure DBR3 includes a fifth planarization layer PLN5 and a sixth planarization layer PLN6. The fifth planarization layer PLN5 is located on the side of the sixth planarization layer PLN6 closest to the light-emitting element 10. In other words, along the first direction x, the fifth planarization layer PLN5, the sixth planarization layer PLN6, the third planarization layer PLN3, the fourth planarization layer PLN4, the first planarization layer PLN1, and the second planarization layer PLN2 are sequentially stacked.

[0080] As can be seen from the above embodiments, the Bragg reflection structure can reflect light directed towards array layer 01 back. In the embodiments provided by the present invention, the first Bragg reflection structure DBR1 and the second Bragg reflection structure DBR2 are used to reflect light of different colors, that is, different wavelengths, to improve the brightness of the display panel and prevent the light from affecting the driving devices on array layer 01.

[0081] Furthermore, referring to Figure 7 The thin-film transistor M disposed on the driving layer 011 further includes a third thin-film transistor M3, and the source or drain of the third thin-film transistor M3 is connected to the third light-emitting element 103 through a via K3 penetrating the reflective layer 012.

[0082] In one optional embodiment, the first Bragg reflection structure DBR1 corresponds to the emission color of the first light-emitting element 101, the second Bragg reflection structure DBR2 corresponds to the emission color of the second light-emitting element 102, and the third Bragg reflection structure DBR3 corresponds to the emission color of the third light-emitting element 103.

[0083] It is understood that, in the embodiments provided by this invention, the light-emitting element 10, comprising a first light-emitting element 101, a second light-emitting element 102, and a third light-emitting element 103, each emitting a different color, can be a Red Micro LED, a Green Micro LED, and a Blue Micro LED, respectively. Since the size of Micro LEDs is at the micrometer level, mixing Micro LEDs of different colors in a small display area can produce different colors, achieving high resolution for the display panel.

[0084] It should be noted that although the reflective layer 012 includes three Bragg reflection structures in this embodiment of the invention, the invention should not be limited to the specific number of Bragg reflection structures. As long as the reflective layer 012 is disposed between the driving layer 011 and the light-emitting element 012, the design concept of the reflective layer 012 including Bragg reflection structures should fall within the protection scope of this invention.

[0085] In one optional embodiment provided by the present invention, the refractive index n6 of the sixth planarization layer PLN6 is less than the refractive index n5 of the fifth planarization layer PLN5.

[0086] It is understandable that the third Bragg reflector structure DBR3 satisfies the condition that the refractive index n6 of the sixth planarization layer PLN6 is less than the refractive index n5 of the fifth planarization layer PLN5. For example, if the third Bragg reflector structure DBR3 corresponds to the emission color of the third light-emitting element 103, when the light emitted by the third light-emitting element 103 pointing towards the array layer 01 passes through the fifth planarization layer PLN5 and the sixth planarization layer PLN6 (i.e., from an optically denser medium to an optically less dense medium), total internal reflection will occur at the interface between the fifth and sixth planarization layers PLN5 and PLN6. The reflected light will then be emitted along the light-emitting surface. This not only fully utilizes the light emitted by the light-emitting element 10 to improve the brightness of the display panel, but also prevents the light emitted by the light-emitting element 10 from shining on the driving device located in the driving layer 011, thus avoiding any impact on the driving device and consequently affecting the display effect.

[0087] Furthermore, the refractive index n5 of the fifth planarization layer PLN5 and the refractive index n6 of the sixth planarization layer PLN6 are also determined by the materials of the fifth planarization layer PLN5 and the sixth planarization layer PLN6 themselves. Specifically, the material of the fifth planarization layer PLN5 can be TiO2, Ta2O5, HfO2, Ti3O5, Nb2O5, etc. The material of the sixth planarization layer PLN6 can be SiO2, SiN... x Al2O3, MgF, etc.

[0088] In one optional embodiment provided by the present invention, the thickness of the third Bragg reflector structure DBR3 along the first direction x is different from the thickness of the first Bragg reflector structure DBR1 and the second Bragg reflector structure DBR2.

[0089] It is understood that the third Bragg reflector structure DBR3 includes a fifth planarization layer PLN5 and a sixth planarization layer PLN6. The thicknesses of the fifth planarization layer PLN5 and the sixth planarization layer PLN6 are N5λ / 4 and N6λ / 4, respectively. Here, N5 and N6 are both positive integers; λ is the wavelength of the emitted color of the light-emitting element 10.

[0090] For example, when the first Bragg reflection structure DBR1 corresponds to the emission color of the first light-emitting element 101, the second Bragg reflection structure DBR2 corresponds to the emission color of the second light-emitting element 102, and the third Bragg reflection structure DBR3 corresponds to the emission color of the third light-emitting element 103, and the wavelength of the emission color of the third light-emitting element 101 is λ3, then the thickness of the third Bragg reflection structure DBR3 is the sum of the fifth planarization layer PLN5 and the sixth planarization layer PLN6, which is N5λ3 / 4 + N6λ3 / 4, where N5 and N6 are both positive integers. In the embodiment provided by the present invention, the thickness of the third Bragg reflection structure DBR3, that is, N5λ3 / 4 + N6λ3 / 4, is different from both the first Bragg reflection structure DBR1 and the second Bragg reflection structure DBR2. In this way, it can not only satisfy the requirement of reflecting the light emitted by the third light-emitting element 103, improving the brightness of the display panel, and preventing the light emitted by the light-emitting element 10 from shining on the driving device located in the driving layer 011 and affecting the driving device, but also reduce the overall thickness of the display panel and improve the user experience.

[0091] Based on the same inventive concept, the present invention also provides a display device, referring to... Figure 8 and Figure 9 As shown, where, Figure 8 This is a top view of a display device provided in an embodiment of the present invention. Figure 9 This is a schematic cross-sectional view of a display device along line AA provided in an embodiment of the present invention. The display device 100 includes the display panel in any of the above embodiments. The display device 100 also includes a cover plate 20 located on the side of the light-emitting element 10 away from the array layer 01.

[0092] The display device 100 provided in this embodiment of the invention can be any electronic device with display function, such as a touch screen, mobile phone, tablet computer, laptop computer, e-reader, or television. The display device 100 provided in this embodiment of the invention has the beneficial effects of the display panel provided in this embodiment of the invention. For details, please refer to the specific descriptions of the display panel in the above embodiments; these descriptions will not be repeated here.

[0093] Understandable Figure 9 The shape of the display device 100 is illustrated using only a rounded rectangle structure as an example. In some other embodiments of the present invention, the display device 100 may also be a rounded rectangle, a circle, an ellipse or any other feasible shape. The present invention does not specifically limit this.

[0094] In summary, the display panel and display device provided by the present invention achieve at least the following beneficial effects:

[0095] The display panel provided by this invention has a reflective layer disposed between the driving layer and the light-emitting element. The reflective layer includes a first planarization layer and a second planarization layer that can form a first Bragg reflection structure. The first and second planarization layers not only meet the requirement of forming a relatively flat reference surface on the driving layer for arranging the light-emitting element, but also enable total internal reflection of the light emitted by the light-emitting element pointing towards the array layer. The first Bragg reflection structure can reflect the light emitted by the light-emitting element back, which not only improves the brightness of the display panel, but also prevents the light pointing towards the array layer from affecting the driving device located on the driving layer, thereby improving the display effect.

[0096] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A display panel, characterized in that, include: An array layer and multiple light-emitting elements located on one side of the array layer; The array layer includes at least a driving layer and a reflective layer, with the reflective layer located between the driving layer and the light-emitting element; The reflective layer includes a first planarization layer and a second planarization layer, wherein the first planarization layer is located on the side of the second planarization layer closer to the light-emitting element; The first planarization layer and the second planarization layer constitute a first Bragg reflection structure; The reflective layer further includes a third planarization layer and a fourth planarization layer; the third planarization layer is located on the side of the fourth planarization layer closest to the light-emitting element; the fourth planarization layer is located on the side of the first planarization layer closest to the light-emitting element; The light-emitting element includes at least a first light-emitting element and a second light-emitting element, wherein the light-emitting color of the first light-emitting element and the light-emitting color of the second light-emitting element are different; The third planarization layer and the fourth planarization layer constitute a second Bragg reflection structure; Along the first direction, the thickness of the first Bragg reflector structure is different from the thickness of the second Bragg reflector structure, and the first direction is the direction in which the light-emitting element points to the array layer.

2. The display panel according to claim 1, characterized in that, The refractive index of the second planarization layer is less than that of the first planarization layer.

3. The display panel according to claim 1, characterized in that, The thickness of the first planarization layer is ; The thickness of the second planarization layer is ; in, , All are positive integers; The wavelength of the emitted color of the light-emitting element.

4. The display panel according to claim 1, characterized in that, The driving layer is provided with thin-film transistors; The source or drain of the thin-film transistor is connected to the light-emitting element through a via.

5. The display panel according to claim 4, characterized in that, The light-emitting element includes a first electrode and a second electrode. The first electrode is connected to the source or drain of the thin-film transistor through the via, and the second electrode is connected to a common electrode layer.

6. The display panel according to claim 1, characterized in that, The refractive index of the fourth planarization layer is less than that of the third planarization layer.

7. The display panel according to claim 1, characterized in that, The reflective layer also includes a fifth planarization layer and a sixth planarization layer; The fifth planarization layer is located on the side of the sixth planarization layer closest to the light-emitting element; The sixth planarization layer is located on the side of the third planarization layer closest to the light-emitting element; The light-emitting element further includes a third light-emitting element; the first light-emitting element, the second light-emitting element, and the third light-emitting element each emit different colors; The fifth planarization layer and the sixth planarization layer constitute the third Bragg reflection structure.

8. The display panel according to claim 7, characterized in that, The refractive index of the sixth planarization layer is less than that of the fifth planarization layer.

9. The display panel according to claim 7, characterized in that, Along the first direction, the thickness of the third Bragg reflector is different from the thicknesses of the first Bragg reflector and the second Bragg reflector, and the first direction is the direction in which the light-emitting element points to the array layer.

10. A display device, characterized in that, The display panel includes any one of claims 1-9.

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