CN116390587A - Display panel and display device - Google Patents

Abstract

The present disclosure provides a display panel and a display apparatus, the display panel including a substrate and a plurality of light emitting devices on the substrate, the plurality of light emitting devices including at least two light emitting devices having different light emission colors. The light emitting device includes a light emitting functional layer, a reflective layer, and a dielectric stack. The reflective layer is located between the light emitting functional layer and the substrate. The medium lamination layers are positioned between the reflecting layers and the luminous functional layers, wherein each medium lamination layer comprises medium layers with different refractive indexes, the luminous devices with different luminous colors correspondingly comprise the medium layers with different optical thicknesses, the medium layers are configured to enhance reflection of light rays with the same wave band as the light rays emitted by the corresponding luminous devices, and the contrast ratio of the display images can be improved by reducing reflection of the light rays with other wave bands through the medium lamination layers.

Description

Display panel and display device

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a display panel and a display device including the display panel.

Background

An Organic Light-Emitting Diode (OLED) is an Organic thin film electroluminescent device, which has the advantages of simple manufacturing process, low cost, low power consumption, high brightness, wide viewing angle, high contrast ratio, and capability of realizing flexible display, and has been greatly paid attention to and widely used in electronic display products.

However, current electronic display products are limited to designs of their own structures, and it is difficult to improve the contrast of a display image while improving the light extraction rate.

Disclosure of Invention

A first aspect of the present disclosure provides a display panel including a substrate and a plurality of light emitting devices on the substrate, the plurality of light emitting devices including at least two light emitting devices having different light emission colors. The light emitting device includes a light emitting functional layer, a reflective layer, and a dielectric stack. The reflective layer is located between the light emitting functional layer and the substrate. The medium lamination layers are positioned between the reflecting layers and the luminous functional layers, wherein each medium lamination layer comprises medium layers with different refractive indexes, the luminous devices with different luminous colors correspondingly comprise the medium layers with different optical thicknesses, and the medium layers are configured to enhance reflection of light rays with the same wave band as the light rays emitted by the corresponding luminous devices and reduce reflection of light rays with other wave bands.

In the above scheme, by arranging the dielectric stack, part of the incident ambient light which accords with the luminous color of the luminous device can be reflected in an enhanced way, and the light of other colors is weakened, so that the reflection of the reflecting layer on the light of other colors is reduced, and the contrast ratio of the displayed image is improved.

In one embodiment of the first aspect of the present disclosure, in each light emitting device, the optical thickness of the dielectric layer satisfies n×h= (K) _x +1/4)λ _x Wherein N is the refractive index of the dielectric layer, H is the thickness of the dielectric layer, K _x Is natural number lambda _x Is the reference wavelength of the light emitted by the light emitting device, and n×h is the optical thickness of the dielectric layer. For example, further, the reference wavelength is a center wavelength of light emitted from the light emitting device.

In one embodiment of the first aspect of the present disclosure, in the light emitting device of at least one light emitting color, the optical thickness of the dielectric layer satisfies n×h= (K) _y +1/2)λ _y Wherein K is _y Is natural number lambda _y For the reference wavelength of the light emitted by the light emitting devices of the other light emitting colors. For example, further, lambda _y The center wavelength of the light emitted from the light emitting devices of the other light emitting colors.

In the above scheme, the dielectric stack in each light emitting device can perform interference cancellation on other color light, so that the reflection of the reflecting layer in the light emitting device on other color light is further reduced, and the contrast ratio of the displayed image is further improved.

In one embodiment of the first aspect of the disclosure, each dielectric stack includes a first dielectric layer and a second dielectric layer, the first dielectric layer and the second dielectric layer are arranged along a thickness direction, a refractive index of the first dielectric layer is smaller than a refractive index of the second dielectric layer, and a dielectric layer farthest from the reflective layer in each dielectric stack is the second dielectric layer. For example, each dielectric stack includes a dielectric layer that is divided into a plurality of groups, the dielectric layer of each group being divided into a first dielectric layer and a second dielectric layer, the first dielectric layer having a refractive index that is less than the refractive index of the second dielectric layer. Further, in each group, the first dielectric layer is located between the second dielectric layer and the reflective layer.

In the scheme, the plurality of groups of medium layers with refractive indexes alternately arranged can enhance reflection for the light rays with the same color as the emergent light rays of the light emitting device in the ambient light for a plurality of times so as to further improve the contrast ratio of the display image.

In another embodiment of the first aspect of the present disclosure, in each of the dielectric stacks, the refractive index of the dielectric layer increases sequentially in a direction of the reflective layer away from the substrate.

In one embodiment of the first aspect of the present disclosure, the dielectric stack is a conductive layer.

In one embodiment of the first aspect of the present disclosure, where the dielectric stack is a conductive layer, the dielectric layer in the dielectric stack that is the greatest distance to the reflective layer comprises a high work function material.

In another embodiment of the first aspect of the present disclosure, in case the dielectric stack is a conductive layer, the light emitting device further comprises a transparent electrode located between the light emitting functional layer and the dielectric stack, the transparent electrode comprises a high work function material to act as an anode of the light emitting device, and the transparent electrode is connected to the reflective layer through the dielectric stack.

In another embodiment of the first aspect of the present disclosure, the dielectric stack is a semiconductor layer.

In one embodiment of the first aspect of the present disclosure, where the dielectric stack is a semiconductor layer, the dielectric stack comprises a hole material. For example, further, some light emitting devices further include an additional dielectric layer between the dielectric stack and the reflective layer, and the additional dielectric layer is co-layered and co-material with the dielectric stack in other light emitting devices to form a common dielectric layer.

In the scheme, the additional dielectric layer and the dielectric lamination in the part of the light-emitting device are actually integrated film layers, so that an additional patterning process is not needed to be carried out on the additional dielectric layer to form the dielectric lamination in the part of the light-emitting device independently, which is beneficial to reducing the preparation process flow of the display panel and reducing the cost.

In another embodiment of the first aspect of the present disclosure, the dielectric stack is an insulating layer. For example, further, the light emitting device further includes a transparent electrode located between the light emitting functional layer and the dielectric stack and including a high work function material to function as an anode of the light emitting device. For example, still further, a via is disposed in the dielectric stack, and the transparent electrode is connected to the reflective layer through the via; and/or, the orthographic projection of at least part of the edge of the transparent electrode on the surface of the reflecting layer is positioned outside the orthographic projection of the dielectric lamination on the surface of the reflecting layer, and the edge of the transparent electrode is connected with the edge of the reflecting layer.

A second aspect of the present disclosure provides a display device including the display panel in the first aspect.

Drawings

Fig. 1 is a schematic plan view of a display panel according to an embodiment of the disclosure.

FIG. 2 is a cross-sectional view of the display panel of FIG. 1 along line M-N.

Fig. 3 is an enlarged view of an anode structure of the display panel shown in fig. 2.

Fig. 4 is a schematic structural diagram of a dielectric stack in a display panel according to an embodiment of the present disclosure.

Fig. 5 is a schematic diagram of another structure of a dielectric stack in a display panel according to an embodiment of the disclosure.

Fig. 6 is an enlarged view of another anode structure provided in an embodiment of the present disclosure.

Fig. 7 is an enlarged view of a portion of a structure of a display panel according to an embodiment of the present disclosure, which illustrates a connection relationship between an anode structure and a portion of a structure in a substrate.

Fig. 8 is an enlarged view of another anode structure of a display panel according to an embodiment of the present disclosure.

Fig. 9 is an enlarged view of another anode structure of a display panel according to an embodiment of the present disclosure.

Fig. 10 is an enlarged view of another anode structure of a display panel provided in an embodiment of the present disclosure, showing a dielectric stack of the anode structure.

Fig. 11 is an enlarged view of still another anode structure of a display panel according to an embodiment of the present disclosure, showing a dielectric stack of the anode structure.

Fig. 12 is a block diagram of a display panel according to an embodiment of the disclosure.

Detailed Description

The technical solutions of the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is apparent that the described embodiments are only some embodiments of the present specification, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are intended to be within the scope of the present disclosure.

In order to reduce the influence of the contrast of the ambient light display panel, a polarizer may be disposed on the light emitting side of the display panel, but the light emitting rate of the display panel may be greatly reduced, or a color filter may be disposed on the light emitting side of the display panel, while the design thickness of the display panel may be increased, and the manufacturing cost of the display panel may be greatly increased due to the disposition of the color filter.

Embodiments of the present disclosure provide a display panel and a display device to solve at least the above technical problems. The display panel includes a substrate and a plurality of light emitting devices on the substrate, the plurality of light emitting devices including at least two light emitting devices having different light emitting colors. The light emitting device includes a light emitting functional layer, a reflective layer, and a dielectric stack. The reflective layer is located between the light emitting functional layer and the substrate. The medium lamination layers are positioned between the reflecting layers and the luminous functional layers, wherein each medium lamination layer comprises medium layers with different refractive indexes, the luminous devices with different luminous colors correspondingly comprise the medium layers with different optical thicknesses, and the medium layers are configured to enhance reflection of light rays with the same wave band as the light rays emitted by the corresponding luminous devices and reduce reflection of light rays with other wave bands. Therefore, by arranging the dielectric lamination, the incident ambient light and the light rays with the same wave band emitted by the corresponding light emitting device can be enhanced and reflected, and the light rays with other wave bands are reduced and reflected, so that the reflection of the reflecting layer on the light rays with other colors is reduced, and the contrast ratio of the display image is improved.

It should be noted that the optical thickness of the film layer is the product of the actual thickness of the film layer and its refractive index; furthermore, light rays of the same color correspond to the same wavelength band, i.e., the colors of light rays of different wavelength bands are different.

Next, a structure of a display panel and a display device according to at least one embodiment of the present disclosure will be described with reference to the accompanying drawings. In addition, in the drawings, a space rectangular coordinate system is established based on the substrate of the display panel to explain the positional relationship of the structures in the display panel. In the rectangular space coordinate system, the X axis and the Y axis are parallel to the surface of the substrate, and the Z axis is parallel to the surface of the substrate.

As shown in fig. 1 to 3, a planar area of the display panel may be divided into a display area 11 in which a plurality of sub-pixels, such as sub-pixels R, G, B, etc., are arranged, and a frame area 12 may include a bonding area (which may be used to set pads, chips, etc.).

The physical structure of the display panel may include a substrate 10 and a display function layer on the substrate 10, the display function layer including a pixel defining layer 20 and a plurality of light emitting devices 30, the pixel defining layer 20 for defining the light emitting devices 30. The main structure of the sub-pixel R, G, B is a light emitting device 30, and the light emitting device 30 may include an anode structure 100, a light emitting functional layer 200, and a cathode 300 sequentially stacked on a substrate 10. The anode structure 100 includes a reflective layer 110 and a dielectric stack 120. The reflective layer 110 may enable the light emitting device 30 to achieve top emission. The refractive indices of the adjacent dielectric layers (e.g., the first dielectric layer 121 and the second dielectric layer 122) in the dielectric stack 120 are different, and the optical thicknesses of the dielectric layers are set such that light rays of a specific color (a light emitting color of a light emitting device where the light emitting device is located, corresponding to a specific wavelength band) can enhance reflection at the interface of the adjacent dielectric layers due to interference constructive, so that light rays of other colors (other wavelength bands) cannot realize interference constructive after entering the dielectric stack 120, but instead continuously attenuate in the process of passing through the interface of the adjacent dielectric layers, so that the light rays of other colors are difficult to reflect, and accordingly, the influence of ambient light on the contrast of a display image can be reduced.

For example, it is assumed that the light emitting devices in the sub-pixels R, G, B emit red light, green light, and blue light, respectively. In the red subpixel R, the optical thickness of the dielectric layer of the dielectric stack 120 is designed such that red light interference is constructive; in the green subpixel G, the optical thickness of the dielectric layer of the dielectric stack 120 is designed such that green light interference is constructive; and in the blue subpixel B, the optical thickness of the dielectric layer of the dielectric stack 120 is designed such that blue interference is constructive. Thus, in the red subpixel R, after the ambient light visible from the outside is incident into the anode structure, the red light in the ambient light interferes constructively in the dielectric stack 120 to achieve enhanced reflection, while the reflectivity of the other colors of light is reduced. Similarly, in the green sub-pixel G, the green light in the ambient light enhances reflection, while the reflectance of the other color light is reduced, and in the blue sub-pixel B, the blue light in the ambient light enhances reflection, while the reflectance of the other color light is reduced.

In a display panel provided in at least one embodiment of the present disclosure, inIn each light emitting device, the optical thickness of the dielectric layer satisfies n×h= (K) _x +1/4)λ _x Wherein N is the refractive index of the dielectric layer, H is the actual thickness of the dielectric layer, K _x Is natural number lambda _x And N is H which is the optical thickness of the dielectric layer. The formula is a general calculation formula of the optical thickness of the dielectric layer, wherein each parameter is not a fixed value and needs to be determined according to factors such as the luminous color of the luminous device, the material selection of the dielectric layer and the like. Exemplary, as shown in FIG. 3, in the red subpixel R, λ ₁ For the first dielectric layer 121 and the second dielectric layer 122, in the case where the K value is fixed, if the refractive indices N of the two are different, the actual thicknesses H of the two are also different for one wavelength (for example, 590nm, 600nm, 610nm, or the like) in a wavelength region (for example, a wavelength region of 580nm to 620nm, or other wavelength region) corresponding to the red light emitted from the light emitting device 30.

In the case where the dielectric stack plays a role in interference constructive with respect to light of a reference wavelength, the reference wavelength selection criteria are: the dielectric stack has the strongest effect on interference constructive of the light rays with the reference wavelength, and plays a certain role in interference constructive of the light rays in a section near the reference wavelength, so that the reference wavelength can be used as the center wavelength of the light rays emitted by the light emitting device, and the light rays meeting the light emitting requirement of the light emitting device can be subjected to enhanced reflection to a greater extent. For example, assuming that the wavelength range of light emitted from the light emitting device is 580nm to 620nm for the red sub-pixel R, the reference wavelength may be set to 600nm so that red light having a wavelength range of 580nm to 620nm in ambient light may be maximally enhanced in reflection.

The light emitting devices in the display panel are provided with a plurality of types, different types of light emitting devices emit different colors of light, and the wavelengths of the different colors of light are different. Thus, in at least one embodiment of the present disclosure, the wavelength difference of the light emitted by different types of light emitting devices may be utilized to design the dielectric stack to interfere with and cancel one wavelength of light while another wavelength of light is interfered with and canceled, so as to ensure that the reflection of the ambient light conforming to the light emitting color of the light emitting device is enhanced while the reflection of the light of other colors is further reduced. The principle of this scheme will be described below with reference to examples.

In a display panel provided in at least one embodiment of the present disclosure, in a light emitting device of at least one light emitting color, an optical thickness of a dielectric layer satisfies n×h= (K) _y +1/2)λ _y Wherein K is _y Is natural number lambda _y For the reference wavelength of the light emitted by the light emitting devices of the other light emitting colors. Exemplary, as shown in fig. 2 and 3, it is assumed that the wavelength ranges of the outgoing light rays of the light emitting devices in the red sub-pixel R are A1 to A2, the wavelength ranges of the outgoing light rays of the light emitting devices in the green sub-pixel G are B1 to B2, the wavelength ranges of the outgoing light rays of the light emitting devices in the blue sub-pixel B are C1 to C2, and λ ₁ Is any value from interval A1 to A2, lambda ₂ Is any value in the interval B1-B2, and lambda ₃ Any value in the interval C1 to C2. In the red subpixel R, by adjusting λ ₁ 、λ ₂ 、K ₁ And K ₂ Can be such that the optical thickness N x H of the dielectric layers in the dielectric stack 120 tends to (K) ₁ +1/4)λ ₁ Is also prone to (K) ₂ +1/2)λ ₂ . In this manner, the dielectric stack 120 in the red subpixel R can make incident red light interference constructive (enhance reflection) and incident green light interference destructive (attenuate reflection). Likewise, the parameter lambda may be further adjusted ₁ 、λ ₂ 、λ ₃ 、K ₁ 、K ₂ And K ₃ Such that the optical thickness N x H of the dielectric layers in the dielectric stack 120 also tends to (K) ₃ +1/2)λ ₃ As such, the dielectric stack 120 in the red subpixel R may cancel the incident blue interference (attenuate reflection). Accordingly, the sub-pixel G, B can also be designed as such.

In the case where the dielectric stack has an interference cancellation effect on light of the reference wavelength, the reference wavelength selection criteria are: the dielectric stack has the strongest effect of interference cancellation for light having the reference wavelength, but for the vicinity of the reference wavelengthThe light rays in the interval also have a certain interference cancellation effect, so that the reference wavelength can be used as the center wavelength of the light rays emitted by other light emitting devices (different from the light emitting type of the light emitting device where the medium lamination is positioned) so as to weaken and reflect the light rays which do not meet the light emitting requirement of the light emitting devices to a greater extent. For example, for the red subpixel R, λ described above ₂ May be (B2-B1)/2, and lambda is as described above ₃ Is (C2-C1)/2.

In embodiments of the present disclosure, a greater number of dielectric layers may be provided to further enhance interference (constructive and destructive interference) effects for specific light rays, and several arrangements of dielectric layers under the design are described below by way of several specific embodiments.

In the display panel provided in some embodiments of the present disclosure, each dielectric stack includes at least one first dielectric layer and at least one second dielectric layer, the first dielectric layer and the second dielectric layer are arranged along a thickness direction, when each dielectric stack includes a plurality of first dielectric layers and a plurality of second dielectric layers, the first dielectric layers and the second dielectric layers are alternately arranged along the thickness direction, a refractive index of the first dielectric layer is smaller than a refractive index of the second dielectric layer, and a dielectric layer farthest from the reflective layer in each dielectric stack is the second dielectric layer. Illustratively, as shown in FIG. 4, each dielectric stack includes a dielectric layer that is divided into a plurality of groups, e.g., A1, A2, the dielectric layer of each group A1, A2 being divided into a first dielectric layer 121 and a second dielectric layer 122, the refractive index of the first dielectric layer 121 being less than the refractive index of the second dielectric layer 122, and in each group, e.g., A1, the first dielectric layer 121 being closer to the reflective layer 110 than the second dielectric layer 122. Therefore, by arranging the medium layers with multiple groups of refractive indexes alternately arranged, the reflection of the light rays with the same color as the emergent light rays of the light emitting device in the ambient light can be enhanced for multiple times, so that the contrast ratio of the display image is further improved. For example, in the red subpixel R, red light incident on ambient light is reflected at each set of the first dielectric layer 121 and the second dielectric layer 122, and thus, the light extraction rate of the red light can be increased by multiple reflection enhancement.

In the display panel provided in other embodiments of the present disclosure, in each of the stacked dielectric layers, the refractive index of the dielectric layer increases sequentially along the direction of the reflective layer away from the substrate, so that, at the interface of each adjacent dielectric layer, the reflection of ambient light having the same color as that of the light emitting device where the dielectric layer is located can be enhanced, so that the dielectric layer stack can have a relatively smaller actual thickness (the number of dielectric layers can be reduced) while ensuring the enhanced reflection effect. Illustratively, as shown in fig. 5, the dielectric stack includes a first dielectric layer 121, a second dielectric layer 122, a third dielectric layer 123, and a fourth dielectric layer 124 sequentially stacked on the reflective layer 110, and refractive indexes of the first dielectric layer 121, the second dielectric layer 122, the third dielectric layer 123, and the fourth dielectric layer 124 sequentially increase. For example, in the red subpixel R, red light of incident ambient light enters the photophobic medium from the photophobic medium at the interface of the first medium layer 121 and the second medium layer 122, at the interface of the second medium layer 122 and the third medium layer 123, and at the interface of the third medium layer 123 and the fourth medium layer 124, and under the condition that the optical thicknesses of the medium layers satisfy the condition that red light interference is constructive, the red light can realize enhanced reflection at all three interfaces.

In embodiments of the present disclosure, the choice of materials for the dielectric stack is not limited and may be designed according to practical needs, where it is considered that the dielectric stack is designed to avoid affecting the electrical connection relationship between the anode structure and other structures, such as the driving circuit and the light emitting functional layer.

In addition, only from the viewpoint of the light emitting performance of the light emitting device, the host material of the anode needs to be a high work function material, while the host material of the cathode needs to be a low work function material, and the dielectric stack and the reflective layer are mainly used for controlling the propagation direction, reflectance, and the like of the incident light and the excitation light of the light emitting device. In this way, in the process of designing the anode structure, it is only required to ensure that the film layer adjacent to the light-emitting functional layer in the anode structure comprises a high work function material.

Next, several material choices of the dielectric stack and the arrangement of the dielectric stack in the anode structure under different choices will be described separately.

In some embodiments of the present disclosure, the dielectric stack may be a conductive layer. In this case, the dielectric stack may enhance the conductive properties (the thickness of the conductive portion increases) of the anode structure to ensure the light emitting performance of the light emitting device.

For example, in one implementation, where the dielectric stack is a conductive layer, referring again to fig. 3, the dielectric layer that is the largest distance from the reflective layer 110 (e.g., the second dielectric layer 122) may be designed to include a high work function material, such that the dielectric stack 120 may be in direct contact with the light emitting functional layer. For example, the material of the dielectric layer may be ITO, IZO, or the like.

For example, in another implementation, where the dielectric stack is a conductive layer, as shown in fig. 6, the anode structure 100 may further include a transparent electrode 130, the transparent electrode 130 including a high work function material, and the dielectric stack 120 being located between the reflective layer 110 and the transparent electrode 130 such that the transparent electrode 130 is connected to the reflective layer 110 through the dielectric stack 120. For example, the dielectric layer material may be a metal material such as Mg, ag, or the like, or the dielectric layer may be a film layer of an organic or inorganic material doped with conductive particles.

It should be noted that, in the embodiment of the present disclosure, the reflective layer may be provided as a conductive material film layer, and the anode structure is connected to the driving circuit through the reflective layer. Illustratively, as shown in fig. 7, the substrate 10 includes a driving circuit layer including a pixel driving circuit connected with a corresponding light emitting device to control a light emitting state of the light emitting device. The pixel driving circuit may include a plurality of transistors TFT, capacitors, and the like, for example, formed in various forms such as 2T1C (i.e., 2 transistors (TFT) and 1 capacitor (C)), 3T1C, or 7T 1C. In the case where the reflective layer is provided as a conductive material film layer, the reflective layer may be connected to a transistor TFT (e.g., a driving transistor) in the pixel driving circuit.

In the display panel provided in other embodiments of the present disclosure, the dielectric stack is a semiconductor layer, so as to ensure that holes generated by the anode structure can be injected into the light-emitting functional layer, so that no additional high work function material film layer is required.

For example, in one implementation, where the dielectric stack is a semiconductor layer, the dielectric layer may be configured to include a hole material.

In the light emitting device, the light emitting functional layer may include at least a light emitting layer, and may further include a hole injection layer, a hole transport layer, and the like between the light emitting layer and the anode structure, and an electron injection layer, an electron transport layer, and the like between the light emitting layer and the cathode, and may further include an electron blocking layer between the light emitting layer and the anode structure, and a hole blocking layer between the light emitting layer and the cathode. Materials such as a hole injection layer, a hole transport layer, an electron blocking layer, and the like may be referred to as hole materials. As such, in some embodiments of the present disclosure, at least a portion of the dielectric layers in the dielectric stack may be designed as film layers such as a hole injection layer, a hole transport layer, an electron blocking layer, etc., so that the film layers do not need to be disposed in the light emitting functional layer or the number of the film layers may be reduced.

For example, in another exemplary embodiment of the present disclosure, as shown in fig. 8, where the dielectric stack 120 is an insulating layer, the anode structure 30 may further include a transparent electrode 130, where the transparent electrode 130 is located on a side of the dielectric stack 120 facing away from the reflective layer 110 and includes a high work function material. The selection range of the insulating layer material is larger, for example, the insulating layer material can still have higher light transmittance under the condition of larger design thickness of the dielectric layer, so that the design difficulty of the dielectric lamination is reduced.

Where the dielectric stack 120 is an insulating layer, the transparent electrode 130 needs to be directly connected to the reflective layer 110, as embodiments of the present disclosure are not limited in this respect. In the following, several connection modes of the transparent electrode 130 to the reflective layer 110 are exemplarily described by several specific embodiments.

For example, in one embodiment of the present disclosure, as shown in fig. 8, a via 101 is provided in the dielectric stack 120, and a transparent electrode 130 is connected to the reflective layer 110 through the via 101. For example, the via 101 may be further designed to be located outside the pixel opening so as not to affect the flatness of the portion of the anode structure 100 located at the pixel opening, i.e., the front projection of the via 101 onto the substrate 10 is located within the front projection of the pixel defining layer 20 onto the substrate 10.

For example, in another embodiment of the present disclosure, as shown in FIG. 9, the orthographic projection of at least a portion of the edge of the transparent electrode 130 onto the surface of the reflective layer 110 is located outside the orthographic projection of the dielectric stack 120 onto the surface of the reflective layer 110, and the edge of the transparent electrode 130 is connected to the edge of the reflective layer 110.

It should be noted that in other embodiments of the present disclosure, both of the approaches shown in fig. 8 and 9 may be used in combination to reduce the impedance of the anode structure.

In the embodiment of the disclosure, the dielectric stack may be separately disposed in the corresponding light emitting device as shown in fig. 2 to 9, or a portion of the dielectric stack may be extended to other adjacent light emitting devices, so as to reduce the difficulty and flow of the manufacturing process of the display panel, thereby effectively reducing the manufacturing cost of the display panel, which is specifically as follows.

In some embodiments of the present disclosure, referring back to fig. 2, the anode structures of the light emitting devices 30 in the sub-pixels R, G, B are independently disposed to be spaced apart from each other. For sub-pixels with different luminescent colors, the number of dielectric layers therein and K of each dielectric layer _x In the same case, the greater the wavelength of the outgoing light, the greater the thickness of the dielectric stack in the sub-pixel, i.e., the greater the thickness of the dielectric stack in sub-pixel R than the thickness of the dielectric stack in sub-pixel G, which is greater than the thickness of the dielectric stack in sub-pixel B.

In other embodiments of the present disclosure, in some light emitting devices, the anode structure further includes an additional dielectric layer, the additional dielectric layer being located between the dielectric stack and the reflective layer, and the additional dielectric layer being co-layered and co-material with the dielectric stack in other light emitting devices to form a common dielectric layer. In this way, the additional dielectric layer and the dielectric layer stack in the part of the light-emitting device are actually integrated film layers, so that an additional patterning process is not needed to be performed on the additional dielectric layer stack to form the dielectric layer stack in the part of the light-emitting device independently, which is beneficial to reducing the manufacturing process flow of the display panel and reducing the cost. Illustratively, as shown in fig. 10, in the sub-pixel R, additional dielectric layers 120G and 120B are provided, the additional dielectric layer 120B, the additional dielectric layer 120G and the dielectric stack 120 are sequentially stacked on a reflective layer (not shown in fig. 10), the additional dielectric layer 120G is made of the same layer and material as the dielectric stack 120 in the sub-pixel G, and the additional dielectric layer 120B is made of the same layer and material as the dielectric stack 120 in the sub-pixel B. Thus, when the red light in the external environment is incident, the reflection of the red light is enhanced by the dielectric stack 120 to ensure the reflection effect of the red light, and the reflection of the other color light is reduced by the dielectric stack 120, at least part of the light is incident on the additional dielectric layers 120G and 120B.

As shown in fig. 10, the additional dielectric layer 120B may be disposed in the sub-pixel G, so that a patterning process (e.g., photolithography) is not required to be performed when the dielectric stack 120 in the sub-pixel B is fabricated, but only the dielectric film layer is deposited in the display panel to simultaneously form the additional dielectric layer 120B and the dielectric stack 120 in the sub-pixel B, so that a process flow of fabricating the display panel may be simplified. For example, in a practical process, a hole-type structural film layer such as a hole injection layer, a hole transport layer, etc. is generally designed as a common layer for each light emitting device, so that the manufacturing process of the light emitting device is simplified, and therefore, in the case that the dielectric stack and the additional dielectric layer are designed to include a hole material, the additional dielectric layer and the dielectric stack of the same layer can be used as the common layer without further patterning process.

It should be noted that, only the dielectric stack in the sub-pixel with the smallest wavelength of the outgoing light may be designed to be the same layer and the same material as the additional dielectric layers in other sub-pixels, specifically, as shown in fig. 11, in both sub-pixels R and G, an additional dielectric layer 120B is provided, in the sub-pixel R, the additional dielectric layer 120B and the dielectric stack 120 are sequentially stacked on the reflective layer (not shown in fig. 11), and in the sub-pixel G, the additional dielectric layer 120B and the dielectric stack 120 are sequentially stacked on the reflective layer, and the additional dielectric layer 120B is prepared to be the same layer and the same material as the dielectric stack 120 in the sub-pixel B. Thus, in the sub-pixel R, when the red light in the external environment light is incident, the reflection of the red light is enhanced by the dielectric stack 120 to ensure the reflection effect of the red light, and the light of other colors is weakened and reflected by the dielectric stack 120, and part of the light is incident into the additional dielectric layer 120B; in the sub-pixel G, green light in the external environment is first reflected by the dielectric stack 120 to ensure the reflection effect of green light, while other colors of light are attenuated by the dielectric stack 120, and part of the light is incident on the additional dielectric layer 120B.

In embodiments of the present disclosure, the display panel may further include other additional structures. As an example, as shown in fig. 12, the display panel may include an encapsulation layer 40, and the encapsulation layer 40 may be a three-layer encapsulation, that is, the encapsulation layer includes an inorganic encapsulation layer, an organic encapsulation layer, and an inorganic encapsulation layer stacked in this order. For example, the display panel may further include a cover plate 70 and a black matrix 60 positioned at the sub-pixel gap. The black matrix 60 may be disposed on the cover plate 70. The cover plate 70 may be attached to the encapsulation layer 40 by an optical adhesive layer 50. The arrangement of the black matrix 60 and the cover plate 70 is not limited to the case shown in fig. 12, and other designs may be performed according to the actual process.

For example, in some embodiments of the present disclosure, the optical cement layer 50 may include a gray cement (e.g., doped with light absorbing or opaque particles) to limit its light transmittance. The light transmittance of the optical adhesive layer 50 may be limited to 75% or more, so as to avoid the influence on the light output of the display panel. Under this design, the optical adhesive layer 50 may filter a portion of light (ambient light having a color different from that of the light emission of the light emitting device, such as green light, blue light, etc. reflected in the subpixel R) incident on and reflected by the anode structure, and the light flux of the light after being attenuated and reflected by the dielectric stack is reduced, and is further reduced to a greater extent after being filtered by the optical adhesive layer 50, so that the contrast of the display image of the display panel may be improved.

It should be noted that, other functional structures such as touch control, micro-lens, electrostatic prevention and control may be further disposed on the display panel, and the embodiments of the disclosure are not limited herein.

At least one embodiment of the present disclosure provides a display device including the display panel of any one of the embodiments described above. For example, the display device may be any product or component having a display function, such as a television, a digital camera, a mobile phone, a watch, a tablet computer, a notebook computer, a navigator, and the like.

The foregoing description of the preferred embodiments is provided for the purpose of illustration only, and is not intended to limit the scope of the disclosure, since various modifications, equivalents, etc. may be made without departing from the spirit and principles of the disclosure.

Claims (10)

1. A display panel comprising a substrate and a plurality of light emitting devices on the substrate, the plurality of light emitting devices comprising at least two light emitting devices having different emission colors, wherein each of the light emitting devices comprises:

a light-emitting functional layer;

a reflective layer between the light emitting functional layer and the substrate;

and the dielectric layers are arranged between the reflecting layers and the luminous functional layers, each dielectric layer comprises a dielectric layer with different refractive indexes, the luminous devices with different luminous colors correspondingly comprise the dielectric layers with different optical thicknesses, and the dielectric layers are configured to enhance reflection of light rays with the same wave band as the light rays emitted by the corresponding luminous devices and reduce reflection of light rays with other wave bands.

2. The display panel according to claim 1, wherein in each of the light emitting devices, an optical thickness of the dielectric layer satisfies n×h= (K) _x +1/4)λ _x Wherein N is the refractive index of the dielectric layer, H is the thickness of the dielectric layer, K _x Is natural number lambda _x The reference wavelength of the light emitted by the light emitting device is given, and N is H which is the optical thickness of the dielectric layer;

preferably, the reference wavelength is a center wavelength of light emitted from the light emitting device.

3. The display panel of claim 2, wherein in at least one luminescent colorIn the light emitting device, the optical thickness of the dielectric layer satisfies n×h= (K) _y +1/2)λ _y Wherein K is _y Is natural number lambda _y A reference wavelength of light emitted by the light emitting device for other light emitting colors;

preferably lambda _y The center wavelength of the light emitted by the light emitting devices of other light emitting colors.

4. A display panel according to any one of claims 1 to 3, wherein each of the dielectric stacks comprises a first dielectric layer and a second dielectric layer, the first and second dielectric layers being arranged in a thickness direction, a refractive index of the first dielectric layer being smaller than a refractive index of the second dielectric layer, and

the dielectric layer of each dielectric stack furthest from the reflective layer is the second dielectric layer.

5. A display panel according to any one of claims 1 to 3, characterized in that in each of the dielectric stacks the refractive index of the dielectric layer increases in sequence in the direction of the reflective layer facing away from the substrate.

6. A display panel according to any one of claim 1 to 3,

the dielectric stack is a conductive layer;

preferably, in the dielectric stack, the dielectric layer having the largest distance to the reflective layer comprises a high work function material;

preferably, the light emitting device further comprises a transparent electrode located between the light emitting functional layer and the dielectric stack, the transparent electrode comprises a high work function material, and the transparent electrode is connected with the reflective layer through the dielectric stack.

7. A display panel according to any one of claims 1 to 3, wherein the dielectric stack is a semiconductor layer.

8. The display panel of claim 7, wherein the display panel comprises,

the dielectric stack includes a hole material;

preferably, part of the light emitting device further comprises an additional dielectric layer, the additional dielectric layer is located between the dielectric stack and the reflective layer, and the additional dielectric layer is co-layered and co-material with the dielectric stacks in other light emitting devices to form a common dielectric layer.

9. The display panel of claim 1, wherein the dielectric stack is an insulating layer, the light emitting device further comprises a transparent electrode positioned between the light emitting functional layer and the dielectric stack, and the transparent electrode comprises a high work function material,

preferably, a via hole is arranged in the dielectric stack, and the transparent electrode is connected with the reflecting layer through the via hole; and/or, the orthographic projection of at least part of the edge of the transparent electrode on the surface of the reflecting layer is positioned outside the orthographic projection of the dielectric lamination on the surface of the reflecting layer, and the edge of the transparent electrode is connected with the edge of the reflecting layer.

10. A display device comprising the display panel according to any one of claims 1 to 9.

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