Display panel and display device

Abstract

Disclosed is a display panel, comprising a base substrate and a plurality of sub-pixels. Each sub-pixel comprises a driving transistor, a light-emitting element and a pixel definition layer. The light-emitting element is provided with a first electrode, a second electrode and a light-emitting material layer located between the first electrode and the second electrode, the first electrode being electrically connected to a source or drain of the driving transistor, and the first electrode comprising a central region and an edge region surrounding the central region. The pixel definition layer covers a portion of the edge region of the first electrode. The first electrode comprises a reflective layer, a transparent conductive layer, and a dielectric layer located between the reflective layer and the transparent conductive layer, the part of the reflective layer located in the central region and the second electrode forming a first optical cavity, and the part of the reflective layer located in the edge region and the second electrode forming a second optical cavity. At least one of the reflective layer, the transparent conductive layer and the dielectric layer has different thicknesses in the central region and the edge region, such that the cavity length of the first optical cavity is different from the cavity length of the second optical cavity. Further disclosed is a display device.

Description

Display panel and display device Technical Field

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

[0002] Silicon-based organic light-emitting diode (OLED) displays are expected to become the preferred display solution for ARVR due to their high contrast, high response speed and high PPI. The brightness of silicon-based OLEDs is currently difficult to meet the display requirements of ARVR. In order to improve the display brightness of silicon-based OLEDs, strong microcavity structures are used in related technologies to improve the brightness of display devices. Generally, the microcavity effect in the edge area of ​​a sub-pixel is different from that in the central area. In traditional OLED devices, due to their large size, the edge area of ​​the sub-pixel occupies a small proportion of the entire display area, and the impact of the edge effect can be ignored. However, the sub-pixel size of silicon-based OLEDs is extremely small. For example, the size of a silicon-based OLED sub-pixel is generally 5-10μm, the sub-pixel size of a mobile phone-sized OLED is tens of μm, and the sub-pixel size of a large-size OLED is even more than 100μm. Such a small size causes the edge area to account for more than 10%. At this time, the difference in the microcavity effect between the edge area of ​​the sub-pixel and the central area cannot be ignored, which will cause color deviation at the edge of the sub-pixel, seriously affecting the display effect.

[0003] Summary of the Invention

[0004] According to one aspect of the present disclosure, a display panel is provided, comprising a base substrate and a plurality of sub-pixels arranged on the base substrate, wherein the sub-pixels include:

[0005] A driving transistor is located on the substrate, and has a gate, a source, and a drain;

[0006] a light-emitting element located on a side of the driving transistor away from the substrate, the light-emitting element comprising a first electrode, a second electrode, and a light-emitting material layer located between the first electrode and the second electrode, wherein the first electrode is electrically connected to the source or drain of the driving transistor, and the first electrode comprises a central region and an edge region surrounding the central region; and

[0007] a pixel defining layer, wherein the pixel defining layer covers a portion of an edge region of the first electrode;

[0008] The first electrode includes a reflective layer, a transparent conductive layer, and a dielectric layer located between the reflective layer and the transparent conductive layer; a portion of the reflective layer located in the central region forms a first optical cavity with the second electrode; and a portion of the reflective layer located in the edge region forms a second optical cavity with the second electrode;

[0009] At least one of the reflective layer, the transparent conductive layer and the dielectric layer has different thicknesses in the central region and the edge region, so that the cavity length of the first optical cavity is different from the cavity length of the second optical cavity.

[0010] For example, the reflective layer of the first electrode has the same thickness in the central area and the edge area of ​​the first electrode, and at least one of the transparent conductive layer and the dielectric layer of the first electrode has different thicknesses in the central area and the edge area of ​​the first electrode; the surface of the second electrode facing the first electrode has a protrusion or a depression, and the projection of the protrusion or the depression on the base substrate at least partially overlaps with the projection of the central area of ​​the first electrode on the base substrate.

[0011] For example, the transparent conductive layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the dielectric layer of the first electrode has different thicknesses in the central region and the edge region of the first electrode.

[0012] For example, a surface of the dielectric layer of the first electrode facing the substrate is substantially parallel to the substrate, a thickness of the dielectric layer of the first electrode in a central region is less than a thickness in an edge region, and a surface of the second electrode facing the first electrode has a protrusion, so that a cavity length of the first optical cavity is less than a cavity length of the second optical cavity.

[0013] For example, a surface of the dielectric layer of the first electrode facing the substrate is substantially parallel to the substrate, a thickness of the dielectric layer of the first electrode in a central region is greater than a thickness in an edge region, and a surface of the second electrode facing the first electrode has a depression, so that a cavity length of the first optical cavity is greater than a cavity length of the second optical cavity.

[0014] For example, the dielectric layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the transparent conductive layer of the first electrode has different thicknesses in the central region and the edge region of the first electrode.

[0015] For example, the surface of the transparent conductive layer of the first electrode facing the base substrate is substantially parallel to the base substrate, the thickness of the transparent conductive layer of the first electrode in the central region is thinner than that in the edge region, the surface of the second electrode facing the first electrode has a protrusion, and the cavity length of the first optical cavity is thinner than that of the second optical cavity.

[0016] For example, a surface of the transparent conductive layer of the first electrode facing the base substrate is substantially parallel to the base substrate, a thickness of the transparent conductive layer of the first electrode in a central region is greater than a thickness in an edge region, a surface of the second electrode facing the first electrode has a depression, and a cavity length of the first optical cavity is greater than a cavity length of the second optical cavity.

[0017] For example, the transparent conductive layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the thickness of at least one of the reflective layer and the dielectric layer of the first electrode is different in the central region and the edge region of the first electrode;

[0018] A surface of the second electrode facing the first electrode is substantially parallel to the base substrate.

[0019] For example, the reflective layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the dielectric layer of the first electrode has different thicknesses in the central region and the edge region of the first electrode.

[0020] For example, a surface of the dielectric layer of the first electrode away from the substrate is substantially parallel to the substrate, a thickness of the dielectric layer of the first electrode in a central region is thinner than a thickness in an edge region, and a cavity length of the first optical cavity is thinner than a cavity length of the second optical cavity.

[0021] For example, a surface of the dielectric layer of the first electrode away from the substrate is substantially parallel to the substrate, a thickness of the dielectric layer of the first electrode in a central region is greater than a thickness in an edge region, and a cavity length of the first optical cavity is greater than a cavity length of the second optical cavity.

[0022] For example, the reflective layer of the first electrode has different thicknesses in the central area and edge area of ​​the first electrode, the dielectric layer of the first electrode has different thicknesses in the central area and edge area of ​​the first electrode, and the sum of the thicknesses of the reflective layer and the dielectric layer of the first electrode is substantially the same in the central area and edge area of ​​the first electrode.

[0023] For example, the surface of the dielectric layer of the first electrode away from the base substrate and the surface of the reflective layer facing the base substrate are both substantially parallel to the base substrate, the thickness of the dielectric layer of the first electrode in the central region is thinner than that in the edge region, and the thickness of the reflective layer of the first electrode in the central region is thicker than that in the edge region.

[0024] For example, the surface of the dielectric layer of the first electrode away from the base substrate and the surface of the reflective layer facing the base substrate are both substantially parallel to the base substrate, the thickness of the dielectric layer of the first electrode in the central region is greater than that in the edge region, and the thickness of the reflective layer of the first electrode in the central region is less than that in the edge region.

[0025] For example, the dielectric layer includes a first material located in a central region of the first electrode and a second material located in an edge region of the first electrode, and the etching rates of the first material and the second material are different.

[0026] For example, one of the first material and the second material is SiNx, and the other is SiOx.

[0027] For example, the equivalent refractive index of each film layer in the first optical cavity is different from the equivalent refractive index of each film layer in the second optical cavity.

[0028] For example, the first optical cavity and the second optical cavity satisfy the following conditions:

[0029] Wherein, h1 represents the cavity length of the first optical cavity, h2 represents the cavity length of the second optical cavity, n is a positive integer, λ represents the central wavelength of light emitted by the sub-pixel, N1 represents the equivalent refractive index of each film layer in the first optical cavity, and N2 represents the equivalent refractive index of each film layer in the second optical cavity.

[0030] For example, the edge region of the first electrode includes a plurality of nested annular sub-regions, and at least one of the reflective layer, the transparent conductive layer and the dielectric layer has different thicknesses in adjacent annular sub-regions, so that the portion of the reflective layer located in each sub-region forms a sub-optical cavity with the second electrode, and adjacent sub-optical cavities have different cavity lengths.

[0031] For example, the area of ​​the central region is larger than the areas of each annular sub-region, and among the multiple annular sub-regions, the annular sub-region closer to the central region has a larger area.

[0032] For example, the plurality of sub-pixels include a first sub-pixel, a second sub-pixel, and a third sub-pixel, and the colors of the first sub-pixel, the second sub-pixel, and the third sub-pixel are different from each other.

[0033] Among them, Src / Sr<Sgc / Sg<Sbc / Sb, and Sr<Sg<Sb,

[0034] Wherein Sr, Sg, and Sb represent the areas of the opening regions of the first sub-pixel, the second sub-pixel, and the third sub-pixel, respectively; Src, Sgc, and Sbc represent the areas of the central regions of the first electrodes of the first sub-pixel, the second sub-pixel, and the third sub-pixel, respectively; wherein the opening region is the region of the first electrode not covered by the pixel defining layer.

[0035] For example, 80%<Src / Sr<Sgc / Sg<Sbc / Sb<95%.

[0036] For example, among sub-pixels of the same color, the area ratio of the central area of ​​the first electrode to the opening area of ​​the sub-pixel located in the central area of ​​the display panel is different from the area ratio of the central area of ​​the first electrode to the opening area of ​​the sub-pixel located in the central area of ​​the display panel.

[0037] For example, the edge area of ​​the first electrode includes a first edge area covered by the pixel defining layer and a second edge area not covered by the pixel defining layer, wherein the thickness of at least one of the reflective layer, the transparent conductive layer and the dielectric layer in the central area is different from the thickness in the first edge area and the second edge area.

[0038] For example, the edge area of ​​the first electrode includes a first edge area covered by the pixel defining layer and a second edge area not covered by the pixel defining layer, wherein at least one of the reflective layer, the transparent conductive layer and the dielectric layer has a thickness in the central area that is different from a thickness in the second edge area.

[0039] For example, the sub-pixel further includes a via hole for electrically connecting the first electrode to the source or drain of the driving transistor.

[0040] There is a first distance between an edge of a central region of the first electrode facing the via hole and an edge of an opening region of the sub-pixel;

[0041] There is a second distance between an edge of a central region of the first electrode facing away from the via hole and an edge of the opening region of the sub-pixel, and the second distance is smaller than the first distance.

[0042] For example, when the via hole is located inside the opening area of ​​the sub-pixel, the first distance and the second distance have a first ratio; when the via hole is located outside the opening area of ​​the sub-pixel, the first distance and the second distance have a second ratio, wherein the first ratio is greater than the second ratio.

[0043] For example, the pixel defining layer includes a covering portion covering the first electrodes of adjacent sub-pixels and a non-covering portion located between the first electrodes of adjacent sub-pixels;

[0044] The reflective layers of adjacent sub-pixels are continuous to form a total reflective layer, the total reflective layer including a first reflective portion located within the opening area and a second reflective portion located outside the opening area, the second reflective portion including a first sub-portion and second sub-portions located on both sides of the first sub-portion, a projection of the first sub-portion on the base substrate at least partially overlaps with a projection of an uncovered portion of the pixel defining layer on the base substrate, and a projection of the second sub-portion on the base substrate at least partially overlaps with a projection of a covered portion of the pixel defining layer on the base substrate;

[0045] In which, a surface of the first subpart of the second reflecting part away from the substrate side and a surface of the second subpart away from the substrate side have a first height difference, a surface of the covering part of the pixel defining layer away from the substrate side and a surface of the non-covering part of the pixel defining layer away from the substrate side have a second height difference, wherein the difference between the first height difference and the second height difference is within a preset range.

[0046] For example, |ΔDpdl-Δreflect| / Δreflect<5%,

[0047] Wherein Δreflect represents the first height difference, and ΔDpdl represents the second height difference.

[0048] For example, the surface of the non-covered part of the pixel defining layer away from the substrate side is lower than the surface of the covered part of the pixel defining layer away from the substrate side; the surface of the first sub-part of the second reflecting part away from the substrate side is lower than the surface of the second sub-part away from the substrate side.

[0049] For example, the first sub-portion and the second sub-portion have the same thickness, and a surface of the first sub-portion close to the substrate is lower than a surface of the second sub-portion close to the substrate.

[0050] For example, the covering portion of the pixel defining layer has an undercut structure on the side facing the non-covering portion; the thickness of the first sub-portion of the second reflecting portion is less than the thickness of the second sub-portion, and the surface of the first sub-portion close to the substrate is basically flush with the surface of the second sub-portion close to the substrate.

[0051] For example, a surface of the non-covered portion of the pixel defining layer away from the base substrate is lower than a surface of the transparent conductive layer of the first electrode close to the base substrate;

[0052] The surface of the first sub-part away from the substrate is lower than the surface of the second sub-part away from the substrate, and the surface of the first sub-part close to the substrate is substantially flush with the surface of the second sub-part close to the substrate.

[0053] For example, the surface of the non-covered part of the pixel defining layer away from the base substrate is higher than the surface of the covered part of the pixel defining layer away from the base substrate; the surface of the first subpart of the second reflecting part away from the base substrate is higher than the surface of the second subpart away from the base substrate.

[0054] According to another aspect of the present disclosure, a display panel is provided, comprising a base substrate and a plurality of sub-pixels arranged on the base substrate, wherein the sub-pixels include:

[0055] A driving transistor is located on the substrate, and has a gate, a source, and a drain;

[0056] a light-emitting element located on a side of the driving transistor away from the substrate, the light-emitting element comprising a first electrode, a second electrode, and a light-emitting material layer located between the first electrode and the second electrode, wherein the first electrode is electrically connected to the source or drain of the driving transistor, and the first electrode comprises a central region and an edge region surrounding the central region; and

[0057] a pixel defining layer, wherein the pixel defining layer covers at least a portion of an edge region of the first electrode;

[0058] The first electrode includes a reflective layer, a transparent conductive layer, and a dielectric layer located between the reflective layer and the transparent conductive layer; a portion of the reflective layer located in the central region forms a first optical cavity with the second electrode; and a portion of the reflective layer located in the edge region forms a second optical cavity with the second electrode;

[0059] The output light of the first optical cavity has a first central wavelength λ1, and the output light of the second optical cavity has a second central wavelength λ2;

[0060] At least one of the reflective layer, the transparent conductive layer and the dielectric layer has different thicknesses in the central region and the edge region, so that a relative deviation value of |1-λ1 / λ2| between the first central wavelength λ1 and the second central wavelength λ2 is less than 5%.

[0061] For example, the pixel defining layer covers the entire edge region of the first electrode, and a thickness of at least one of the reflective layer, the transparent conductive layer and the dielectric layer in the central region is different from a thickness in the entire edge region.

[0062] For example, the reflective layer of the first electrode has the same thickness in the central area and the edge area of ​​the first electrode, and at least one of the transparent conductive layer and the dielectric layer of the first electrode has different thicknesses in the central area and the edge area of ​​the first electrode; the surface of the second electrode facing the first electrode has a protrusion or a depression, and the projection of the protrusion or the depression on the base substrate at least partially overlaps with the projection of the central area of ​​the first electrode on the base substrate.

[0063] For example, the transparent conductive layer of the first electrode has the same thickness in the central area and the edge area of ​​the first electrode, and at least one of the reflective layer and the dielectric layer of the first electrode has different thickness in the central area and the edge area of ​​the first electrode; the surface of the second electrode facing the first electrode is basically parallel to the substrate.

[0064] According to another aspect of the present disclosure, a display device is provided, including the display panel according to the embodiment of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] FIG1 is a schematic plan view showing a display panel according to an embodiment of the present disclosure.

[0066] FIG. 2 shows a cross-sectional view of a sub-pixel in a display panel according to an embodiment of the present disclosure.

[0067] FIG3 shows a cross-sectional view of a light-emitting element of a sub-pixel according to an embodiment of the present disclosure.

[0068] FIG4 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0069] FIG5 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0070] FIG6 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0071] FIG7 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0072] FIG8 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0073] FIG9 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0074] FIG10 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0075] FIG. 11A shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0076] FIG11B shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0077] FIG12 shows a schematic plan view of a first electrode of a sub-pixel according to an embodiment of the present disclosure.

[0078] FIG13 shows a plan view schematically illustrating sub-pixels of different colors according to an embodiment of the present disclosure.

[0079] FIG. 14 shows a plan view schematically illustrating sub-pixels of the same color according to an embodiment of the present disclosure.

[0080] FIG15A shows a plan view of a sub-pixel according to an embodiment of the present disclosure.

[0081] FIG15B shows a plan view of a sub-pixel according to another embodiment of the present disclosure.

[0082] FIG16A shows a cross-sectional view of a non-display region of a light-emitting element of a sub-pixel according to an embodiment of the present disclosure.

[0083] FIG16B shows a cross-sectional view of a non-display region of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0084] FIG16C shows a cross-sectional view of a non-display region of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure.

[0085] FIG16D shows a cross-sectional view of a non-display region of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0086] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of them. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure. It should be noted that throughout the drawings, the same elements are represented by the same or similar figure marks. In the following description, some specific embodiments are only for descriptive purposes and should not be understood as any limitation to the present disclosure, but are only examples of the embodiments of the present disclosure. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure. It should be noted that the shapes and sizes of the components in the figures do not reflect the actual size and proportion, but only illustrate the contents of the embodiments of the present disclosure.

[0087] Unless otherwise defined, technical or scientific terms used in the embodiments of the present disclosure shall have the same general meaning as those skilled in the art. The terms "first," "second," and similar terms used in the embodiments of the present disclosure do not denote any order, quantity, or importance, but are merely used to distinguish different components.

[0088] In addition, in the description of the embodiments of the present disclosure, the term "connected" or "connected to" may refer to a direct connection between two components or a connection between two components via one or more other components. In addition, the two components may be connected or coupled via a wired or wireless manner.

[0089] FIG1 is a schematic plan view showing a display panel according to an embodiment of the present disclosure.

[0090] As shown in Figure 1, the display panel 100 includes a base substrate 110 and a plurality of sub-pixels Px arranged on the base substrate 110, wherein the plurality of sub-pixels Px1 are arranged in an array. In Figure 2, the plurality of sub-pixels Px are arranged in N rows and M columns. The display panel 100 may also be provided with a plurality of gate lines G1, G2, ...GN electrically connected to the plurality of sub-pixels Px. The display panel 100 may also be provided with a plurality of data lines D1, D2, ...DM electrically connected to the plurality of sub-pixels Px. In Figure 1, N rows of sub-pixels Px are connected to N gate lines G1, G2, ...GN in a one-to-one correspondence, and M columns of sub-pixels Px are connected to M data lines D1, D2, ...DM in a one-to-one correspondence, that is, each row of sub-pixels is connected to a gate line, and each column of sub-pixels is connected to a data line. However, the embodiments of the present disclosure are not limited thereto, and the number and connection method of the gate lines and data lines can be selected as needed. For example, two gate lines can be connected to each row of sub-pixels, and the number of gate lines is twice the number of sub-pixel rows; or one data line can be connected to every two columns of sub-pixels, and the number of data lines is half the number of sub-pixel columns, and so on.

[0091] During operation, the gate drive circuit applies gate drive signals to gate lines G1 to GN to turn on each row of sub-pixels Px. The source drive circuit applies source drive signals to data lines D1 to DM to cause the turned-on sub-pixels Px to display according to the applied source drive signals. In some embodiments, the display panel 100 may further include multiple emission control lines connected to the multiple sub-pixels. The emission drive circuit provides emission control signals to the multiple sub-pixels via the multiple emission control lines.

[0092] FIG. 2 shows a cross-sectional view of a sub-pixel in a display panel according to an embodiment of the present disclosure.

[0093] As shown in FIG2 , at least one of the multiple sub-pixels in the display panel includes a driving transistor having a gate G, a source S, and a drain D. The driving transistor may further include an active layer P-Si located on the base substrate 110, with the gate G located on the side of the active layer P-Si away from the base substrate 110. The driving transistor may further include a first gate insulating layer 202 located between the active layer P-Si and the gate G, a second gate insulating layer 203 located on the side of the gate G away from the base substrate 110, and an interlayer dielectric layer 204 located on the side of the second gate insulating layer 203 away from the base substrate. The source S and the drain D are located on the side of the interlayer dielectric layer 204 away from the base substrate. The sub-pixel may further include a storage capacitor, which includes a first capacitor electrode ED1 and a second capacitor electrode ED2. The first capacitor electrode ED1 is located on the same layer as the gate G, and the second capacitor electrode ED2 is located between the second gate insulating layer 203 and the interlayer dielectric layer 204.

[0094] As shown in FIG2 , the sub-pixel may further include a light-emitting element, which is located on a side of the driving transistor away from the substrate 110. The light-emitting element includes a first electrode 207, a second electrode 212, and a light-emitting material layer 211 located between the first electrode 207 and the second electrode 212. The first electrode 207 is electrically connected to the source S or the drain D of the driving transistor. In some embodiments, the first electrode 207 may be an anode, and the second electrode 212 may be a cathode.

[0095] In some embodiments, the sub-pixel may further include a pixel-defining layer 209. The pixel-defining layer 209 covers at least a portion of the edge region of the first electrode 207 to define an opening region. The opening region may be a portion of the first electrode 207 not covered by the pixel-defining layer 207, and a portion of the surface of the first electrode 207 away from the substrate 110 is exposed through the opening region.

[0096] In some embodiments, the sub-pixel may further include a planarization layer 206. The planarization layer 206 is located on the side of the interlayer dielectric layer 204 away from the base substrate 110. A first electrode 207 is located on the side of the planarization layer 206 away from the base substrate 110 and is connected to the source electrode S or the drain electrode D through the planarization layer 206. A pixel defining layer 209 is located on the side of the planarization layer 206 away from the base substrate 110 and partially covers the first electrode 207.

[0097] In some embodiments, the sub-pixel may further include a buffer layer 201 , which is located between the base substrate 110 and the first gate insulating layer 202 , and the active layer P-Si of the driving transistor is located between the buffer layer 201 and the first gate insulating layer 202 .

[0098] In some embodiments, the sub-pixel may further include a passivation layer 205 , which is located between the planar layer 206 and the interlayer dielectric layer 204 and covers the source S and drain D of the driving transistor. A first electrode 207 passes through the interlayer dielectric layer 206 and the passivation layer 205 and is connected to the source S of the driving transistor.

[0099] In some embodiments, the sub-pixel may further include an encapsulation layer 213. The encapsulation layer 213 is located on a side of the second electrode 212 away from the base substrate 110. In some embodiments, the encapsulation layer 213 may include a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer stacked in sequence.

[0100] The first electrode 207 may be a multi-layer structure, and the reflective layer in the first electrode 207 and the second electrode 212 form an optical cavity. The cavity length of the optical cavity is the distance between the reflective layer of the first electrode 207 and the second electrode 212 in a direction perpendicular to the substrate. When the cavity length h of the optical cavity satisfies the following equation:

[0101] Where h is the cavity length, n is a positive integer, N is the effective refractive index in the microcavity, and λ is the central wavelength of the corresponding sub-pixel. The outgoing light with the central wavelength of the sub-pixel is enhanced due to constructive interference, that is, the brightness is improved.

[0102] Typically, due to limitations in the manufacturing process, the actual cavity length of the edge region of the first electrode may deviate from that of the central region, resulting in:

[0103] That is, the central wavelength of the edge area deviates from the central wavelength of the central area, resulting in color deviation of the sub-pixel edge, such as the sub-pixel edge is reddish, bluish, yellowish, etc., which seriously affects the display effect of silicon-based OLED.

[0104] Embodiments of the present disclosure provide a display panel comprising a substrate and a plurality of sub-pixels disposed on the substrate, wherein the sub-pixels include: a driving transistor disposed on the substrate, the driving transistor having a gate, a source, and a drain; a light-emitting element disposed on a side of the driving transistor away from the substrate, the light-emitting element having a first electrode, a second electrode, and a light-emitting material layer disposed between the first and second electrodes, wherein the first electrode is electrically connected to the source or drain of the driving transistor, the first electrode having a central region and an edge region surrounding the central region; and a pixel-defining layer covering at least a portion of the edge region of the first electrode. The first electrode includes a reflective layer, a transparent conductive layer, and a dielectric layer disposed between the reflective layer and the transparent conductive layer. The portion of the reflective layer disposed in the central region forms a first optical cavity with the second electrode, and the portion of the reflective layer disposed in the edge region forms a second optical cavity with the second electrode. At least one of the reflective layer, the transparent conductive layer, and the dielectric layer has different thicknesses in the central region and the edge region, such that the cavity length of the first optical cavity is different from the cavity length of the second optical cavity.

[0105] FIG3 shows a cross-sectional view of a light-emitting element of a sub-pixel according to an embodiment of the present disclosure.

[0106] 3 , the light emitting element includes a first electrode 207A, a second electrode 212A, and a light emitting material layer 211 located between the first electrode 207A and the second electrode 212A. The above description of the light emitting element is also applicable to this embodiment.

[0107] The first electrode 207A includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 located between the reflective layer L1 and the transparent conductive layer L2. The material of the transparent conductive layer L2 includes, but is not limited to, indium tin oxide. The reflective layer L1 can be a single material layer or a composite material layer, wherein the materials of each layer of the composite material layer include, but are not limited to, Ti, TiN, or Al2O3. As shown in FIG3 , the first electrode 207A has a central region 2071 and an edge region 2072 surrounding the central region 2071. The portion of the reflective layer L1 located in the central region 2071 forms a first optical cavity with the second electrode 212A, and the cavity length of the first optical cavity is h1. The portion of the reflective layer L1 located in the edge region 2072 forms a second optical cavity with the second electrode 212A, and the cavity length of the second optical cavity is h2.

[0108] At least one of the reflective layer L1, the transparent conductive layer L2, and the dielectric layer L3 has different thicknesses in the central region 2071 and the edge region 2072, such that the cavity length h1 of the first optical cavity is different from the cavity length h2 of the second optical cavity. In some embodiments, the reflective layer L1 has the same thickness in the central region 2071 and the edge region 2072, while at least one of the transparent conductive layer L2 and the dielectric layer L3 has different thicknesses in the central region 2071 and the edge region 2072. For example, the reflective layer L1 and the transparent conductive layer L2 have the same thickness in the central region 2071 and the edge region 2072, while the dielectric layer L3 has different thicknesses in the central region 2071 and the edge region 2072. In the example of FIG. 3 , the surface of the dielectric layer L3 of the first electrode 207A facing the substrate is substantially parallel to the substrate, and the thickness h1' of the dielectric layer L3 of the first electrode 207A in the central region 2071 is less than the thickness h2' in the edge region 2072. That is, the surface of the dielectric layer 13 facing the substrate is essentially planar, with the distance from the substrate being essentially uniform across all locations. However, the surface of the dielectric layer 13 facing away from the substrate forms a depression in the central region. Because the transparent conductive layer L2 has the same thickness in the central region 2071 and the edge region 2071, and the luminescent material layer 211 is a film layer of uniform thickness, the surface of the second electrode 212A facing the first electrode 207A has a corresponding protrusion. The projection of this protrusion on the substrate at least partially overlaps with the projection of the central region 2071 of the first electrode 207A on the substrate. As shown in FIG3 , the surface of the second electrode 212A facing the first electrode 207A has a central portion corresponding to the central region 2071 and an edge portion corresponding to the edge region 2072. The central portion of the second electrode 212A is lower in height relative to the substrate than the edge portion, or in other words, the central portion protrudes relative to the edge portion toward the substrate. This ensures that the cavity length h1 of the first optical cavity is shorter than the cavity length h2 of the second optical cavity. In some embodiments, the thickness h1′ of the dielectric layer L3 in the central region 2071 and the thickness h2′ in the edge region 2072 can be designed so that the first optical cavity and the second optical cavity satisfy the following conditions:

[0109] Wherein, h1 represents the cavity length of the first optical cavity, h2 represents the cavity length of the second optical cavity, n is a positive integer, λ represents the central wavelength of the light emitted by the sub-pixel, N1 represents the equivalent refractive index of each film layer in the first optical cavity, and N2 represents the equivalent refractive index of each film layer in the second optical cavity. The optical cavity includes multiple film layers, each of which has its own refractive index. The so-called equivalent refractive index here refers to the refractive index of the single film layer when the various film layers in the optical cavity are equivalent to a single film layer. In the example of Figure 3, the materials of the film layers in the first optical cavity and the second optical cavity are the same, so N1=N2. The dielectric layer L3 can be a multilayer structure including SiOx and / or SiNx, so that the microcavity effects of the central area and the edge area are consistent. In Figure 3, the cavity length h2 of the edge area 2072 is larger than the cavity length h1 of the central area 2071, which can solve the problem of blue edge.

[0110] In some embodiments, the light emitted from the first optical cavity has a first central wavelength λ1, and the light emitted from the second optical cavity has a second central wavelength λ2. In some embodiments, at least one of the reflective layer L1, the transparent conductive layer L2, and the dielectric layer L3 can be designed to have different thicknesses in the central region 2071 and the edge region 2072, such that the relative deviation between the first central wavelength λ1 and the second central wavelength λ2 is |1-λ1 / λ2| less than 5%.

[0111] In the embodiments of the present disclosure, by enabling at least one of the reflective layer, transparent conductive layer, and dielectric layer in the first electrode to have different thicknesses in the center and edge regions, the optical cavity between the reflective layer and the second electrode can have different cavity lengths in the edge and center regions. In this way, a microcavity compensation structure is formed in the edge region of the sub-pixel, so that although the cavity lengths in the edge and center regions of the sub-pixel are different, they can still achieve a substantially identical central wavelength λ, thereby alleviating the problem of color shift at the edge of the sub-pixel due to edge effects and improving the brightness and display uniformity of silicon-based OLED display devices.

[0112] In some embodiments, as shown in FIG3 , the pixel-defining layer 209 covers a portion, but not all, of the edge region 2072 of the first electrode 207A. This allows the projection of the boundary S between the edge region 2072 and the center region 2071 of the first electrode 207A onto the substrate to fall outside the projection of the pixel-defining layer 209 onto the substrate. The edge region 2072 of the first electrode 2072A includes a first edge region 2072a covered by the pixel-defining layer 209 and a second edge region 2072b not covered by the pixel-defining layer 209. At least one of the reflective layer L1, the transparent conductive layer L2, and the dielectric layer L3 has a different thickness in the center region 2071 than in the first edge region 2072a and / or the second edge region 2072b. For example, in FIG3 , the dielectric layer L3 has a first thickness in the center region 2071 and a second thickness in the first edge region 2072a and the second edge region 2072b, where the first thickness is different from the second thickness. Of course, the embodiments of the present disclosure are not limited to this. Taking dielectric layer L3 as an example, dielectric layer L3 may have a first thickness in central region 2071 and first edge region 2072a, and a second thickness different from the first thickness in second edge region 2072b. In other embodiments, dielectric layer L3 may have a first thickness in central region 2071, a second thickness in first edge region 2072a, and a third thickness in second edge region 2072b, where the first, second, and third thicknesses are different. This also applies to reflective layer L1 and transparent conductive layer L2, and will not be further described here.

[0113] In related art, while the edge of the first electrode's opening region is theoretically not covered by the pixel-defining layer and has the same cavity length as the center region, in practice, this can also lead to color shift due to the evaporation shadow effect. In the embodiments of the present disclosure, by making at least one of the reflective layer, transparent conductive layer, and dielectric layer have a different thickness in the center region than in the first and / or second edge regions, different cavity lengths can be achieved between the center region and the first and / or second edge regions, thereby compensating for this color shift.

[0114] Figure 4 shows a cross-sectional view of a light-emitting element of a subpixel according to another embodiment of the present disclosure. The structure of the light-emitting element in Figure 4 is similar to that in Figure 3, differing at least in that the dielectric layer is made of different materials in the central and edge regions. For ease of description, the following will focus on the differences.

[0115] As shown in FIG4 , the light-emitting element also includes a first electrode 207B, a second electrode 212B, and a transparent conductive layer 211 positioned between the first electrode 207B and the second electrode 212B. The first electrode 207B includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 positioned therebetween. The dielectric layer L3 includes a first material positioned in a central region 2071 of the first electrode 207B and a second material positioned in an edge region 2072 of the first electrode 207B. The first material and the second material are different, for example, they may have different etching rates. For example, in FIG4 , the etching rate of the material in the central region (the first material) of the dielectric layer L3 can be set to be higher than the etching rate of the material in the edge region (the second material). This difference in etching rates can be exploited to achieve one-step etching of the central and edge regions by adjusting etching parameters, resulting in the dielectric layer L3 structure shown in FIG4 , where the dielectric layer L3 is thinner in the central region 2071 than in the edge region 2072. In some embodiments, one of the first and second materials of the dielectric layer L3 is SiNx and the other is SiOx. For example, in the example of FIG. 4 , the first material of the dielectric layer L3 is SiNx having a higher etching rate to obtain a lower thickness central portion; the second material is SiOx having a lower etching rate to obtain a higher thickness edge portion.

[0116] In Figure 4 , the first optical cavity and the second optical cavity can also satisfy the above equation (1). In some embodiments, N1≠N2 can be achieved by designing the film layer materials in the first optical cavity and the second optical cavity, for example, by using different materials in the center region and the edge region of the dielectric layer L3.

[0117] Figure 5 shows a cross-sectional view of a light-emitting element of a subpixel according to another embodiment of the present disclosure. The structure of the light-emitting element in Figure 5 is similar to that in Figure 3, differing at least in the structures of the first electrode and the second electrode. For ease of description, the following will focus on the differences.

[0118] As shown in FIG5 , the light-emitting element similarly includes a first electrode 207C, a second electrode 212C, and a transparent conductive layer 211 positioned between the first and second electrodes 207C and 212C. The first electrode 207C includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 positioned therebetween. Unlike FIG3 , the surface of the dielectric layer L3 facing the substrate is substantially parallel to the substrate, and the thickness h1' of the dielectric layer L3 in the central region 2071 is greater than the thickness h2' at the edge regions. In other words, the surface of the dielectric layer 13 facing the substrate is substantially planar, with the distance from the substrate being substantially uniform at all locations. However, the surface of the dielectric layer 13 facing away from the substrate forms a protrusion in the central region. Since the thickness of the transparent conductive layer L2 in the central region 2071 and the edge region 2071 is the same, and the light-emitting material layer 211 is a film layer of uniform thickness, the surface of the second electrode 212C facing the first electrode 207A also has a corresponding depression, that is, it is depressed in a direction away from the substrate. The projection of the depression on the substrate at least partially overlaps with the projection of the central region 2071 of the first electrode 207C on the substrate, as shown in FIG5 . Thus, the cavity length h1 of the first optical cavity is greater than the cavity length h2 of the second optical cavity. In some embodiments, the thickness h1' of the dielectric layer L3 in the central region 2071 and the thickness h2' of the edge region 2072 can be designed so that the first optical cavity and the second optical cavity also satisfy the above equation (1). For the case where the sub-pixel edge is reddish, the structure shown in FIG5 can be adopted, where the cavity length h2 of the edge region 2072 is smaller than the cavity length h1 of the central region 2071, thereby solving the problem of the sub-pixel edge being reddish.

[0119] In some embodiments, the materials of the dielectric layer L3 in the central region and the edge region may be different, for example, they may have different etching rates. In the example of FIG5 , the etching rate of the material (first material) in the central region of the dielectric layer L3 may be lower than the etching rate of the material (second material) in the edge region. In this way, by taking advantage of the difference in etching rates between the two, the etching of the central region and the edge region can be achieved in one step by adjusting the etching parameters, thereby obtaining the dielectric layer L3 structure shown in FIG5 , that is, the thickness of the dielectric layer L3 in the central region 2071 is greater than the thickness in the edge region 2072. In the example of FIG5 , the first material of the dielectric layer L3 is SiOx with a lower etching rate, so as to obtain a central portion with a higher thickness; the second material is SiNx with a higher etching rate, so as to obtain an edge portion with a lower thickness.

[0120] Figure 6 shows a cross-sectional view of a light-emitting element of a subpixel according to another embodiment of the present disclosure. The structure of the light-emitting element in Figure 6 is similar to that in Figure 3, differing at least in the structures of the first and second electrodes. For ease of description, the following will focus on the differences.

[0121] As shown in FIG6 , the light-emitting element also includes a first electrode 207D, a second electrode 212D, and a transparent conductive layer 211 positioned between the first electrode 207D and the second electrode 212D. The first electrode 207D includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 positioned therebetween. Unlike FIG3 , the reflective layer L1 and the dielectric layer L3 have the same thickness in both the central region 2071 and the edge regions 2072 of the first electrode 207D, while the transparent conductive layer L2 has different thicknesses in the central region 2071 and the edge regions 2072 of the first electrode 207D. In the example of FIG6 , the surface of the transparent conductive layer L2 facing the substrate is substantially parallel to the substrate, and the thickness of the transparent conductive layer L2 in the central region 2071 is less than that in the edge regions 2072. In other words, the difference in thickness between the transparent conductive layer L2 in the central region 2071 and the edge region 2072 causes a depression in the central region 2071 on the surface of the first electrode 207D facing away from the substrate. Due to the uniform thickness of the luminescent material layer 211, a corresponding protrusion forms on the surface of the second electrode 212D facing the first electrode 207D. This ensures that the cavity length h1 of the first optical cavity is smaller than the cavity length h2 of the second optical cavity, resolving the blue tint issue at the edges of sub-pixels.

[0122] Figure 7 shows a cross-sectional view of a light-emitting element of a subpixel according to another embodiment of the present disclosure. The structure of the light-emitting element in Figure 7 is similar to that in Figure 6, differing at least in the structures of the first and second electrodes. For ease of description, the following will focus on the differences.

[0123] As shown in Figure 7, the light-emitting element also includes a first electrode 207E, a second electrode 212E, and a transparent conductive layer 211 positioned between the first and second electrodes 207E and 212E. The first electrode 207E includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 positioned therebetween. Unlike Figure 6, the surface of the transparent conductive layer L2 facing the substrate is substantially parallel to the substrate, and the thickness of the transparent conductive layer L2 in the central region 2701 is greater than that in the edge region 2072. In other words, the difference in thickness between the transparent conductive layer L2 in the central region 2071 and the edge region 2072 creates a convexity on the surface of the first electrode 207E facing away from the substrate in the central region 2071. Due to the uniform thickness of the light-emitting material layer 211, the surface of the second electrode 212E facing the first electrode 207E has a corresponding concavity. This ensures that the cavity length h1 of the first optical cavity is greater than the cavity length h2 of the second optical cavity, resolving the reddish cast at the edges of sub-pixels.

[0124] Figure 8 shows a cross-sectional view of a light-emitting element of a subpixel according to another embodiment of the present disclosure. The structure of the light-emitting element in Figure 8 is similar to that in Figure 3, differing at least in the structures of the first and second electrodes. For ease of description, the following will focus on the differences.

[0125] As shown in FIG8 , the light-emitting element also includes a first electrode 207F, a second electrode 212F, and a transparent conductive layer 211 located between the first electrode 207F and the second electrode 212F. The first electrode 207F includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 located therebetween. Unlike FIG3 , the transparent conductive layer L2 of the first electrode 207F has the same thickness in both the central region 2071 and the edge region 2072 of the first electrode, while at least one of the reflective layer L1 and the dielectric layer L3 may have different thicknesses in the central region 2071 and the edge region 2072 of the first electrode. For example, the transparent conductive layer L2 has the same thickness in both the central region 2071 and the edge region 2072 of the first electrode, while the reflective layer L1 and the dielectric layer L3 have different thicknesses in both the central region 2071 and the edge region 2072, and the sum of the thicknesses of the reflective layer L1 and the dielectric layer L3 is substantially the same in both the central region 2071 and the edge region 2072. In the example of FIG8 , the dielectric layer L3 of the first electrode 207F has a thickness that is thinner in the central region 2071 than in the edge region 2072. The reflective layer L1 of the first electrode 207F has a thickness that is thicker in the central region 2071 than in the edge region 2072. Both the surface of the dielectric layer L3 facing away from the substrate and the surface of the reflective layer L1 facing the substrate are substantially parallel to the substrate. Specifically, the upper surface of the reflective layer L1 has a protrusion, and the lower surface of the dielectric layer L3 has a groove that matches the protrusion of the reflective layer L1. This ensures that the thickness of the combined structure of the dielectric layer L3 and the reflective layer L1 is consistent in the central region 2071 and the edge region 2072. Because the transparent conductive layer L2 has the same thickness in the central region 2071 and the edge region 2072, the overall thickness of the first electrode 207F is consistent in both the central and edge regions. Because the luminescent material layer 211 is a film layer of uniform thickness, the surface of the second electrode 212F facing the first electrode 207F is substantially parallel to the substrate, i.e., is substantially planar. In this way, the cavity length h1 of the first optical cavity is smaller than the cavity length h2 of the second optical cavity, which can solve the problem of blue edge of sub-pixel.

[0126] Figure 9 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure. The structure of the light-emitting element in Figure 9 is similar to that in Figure 8, with the difference being at least the structure of the first electrode. For ease of description, the following will primarily describe the differences in detail.

[0127] As shown in FIG9 , the light-emitting element also includes a first electrode 207G, a second electrode 212G, and a transparent conductive layer 211 positioned between the first electrode 207G and the second electrode 212G. The first electrode 207G includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 positioned therebetween. Unlike FIG8 , the surface of the dielectric layer L3 of the first electrode 207G facing away from the substrate and the surface of the reflective layer L1 facing the substrate are both substantially parallel to the substrate. The thickness of the dielectric layer L3 in the central region 2071 is greater than that in the edge region 2072, while the thickness of the reflective layer L1 in the central region 2071 is less than that in the edge region 2072. In other words, the upper surface of the reflective layer L1 has a groove, and the lower surface of the dielectric layer L3 has a protrusion that matches the groove of the reflective layer L1, thereby ensuring that the thickness of the combined structure of the dielectric layer L3 and the reflective layer L1 is consistent in the central region 2071 and the edge region 2072. Because the transparent conductive layer L2 has the same thickness in the center region 2071 and the edge region 2072, the overall thickness of the first electrode 207F is consistent in both the center and edge regions. Since the luminescent material layer 211 is a film of uniform thickness, the surface of the second electrode 212F facing the first electrode 207F is substantially parallel to the substrate, that is, it is generally flat. This ensures that the cavity length h1 of the first optical cavity is greater than the cavity length h2 of the second optical cavity, resolving the reddish cast at the edges of sub-pixels.

[0128] Figure 10 shows a cross-sectional view of a light-emitting element of a sub-pixel according to another embodiment of the present disclosure. The structure of the light-emitting element in Figure 10 is similar to that in Figure 8, with the difference being at least the structure of the first electrode. For ease of description, the following will primarily describe the differences in detail.

[0129] As shown in FIG10 , the light-emitting element also includes a first electrode 207H, a second electrode 212H, and a transparent conductive layer 211 positioned between the first electrode 207H and the second electrode 212H. The first electrode 207H includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 positioned therebetween. Unlike FIG8 , the reflective layer L1 of the first electrode 207H has the same thickness in the central region 2071 and the edge region 2072 of the first electrode, while the dielectric layer L3 of the first electrode 207H has different thicknesses in the central region 2071 and the edge region 2072 of the first electrode. For example, as shown in FIG10 , the surface of the dielectric layer L3 of the first electrode 207H facing away from the substrate (the upper surface in FIG10 ) is substantially parallel to the substrate, i.e., is substantially planar. The thickness of the dielectric layer L3 in the central region 2071 is less than that in the edge region 2072. In other words, the upper surface of the dielectric layer L3 is substantially planar, while the lower surface forms a depression in the central region facing away from the substrate. Because the lower surface of dielectric layer L3 is concave, and the underlying reflective layer L1 has the same thickness in the central region 2071 and the edge region 2072, a corresponding groove structure is formed in the reflective layer L1 within the central region 2071. This groove is filled by the inorganic layer (e.g., planar layer 206) beneath the reflective layer L1. Because the upper surface of dielectric layer L3 is substantially planar, and the upper transparent conductive layer L2 also has the same thickness in the central region 2071 and the edge region 2072, the upper and lower surfaces of the transparent conductive layer L2 are essentially two parallel planes. This ensures that the cavity length h1 of the first optical cavity is smaller than the cavity length h2 of the second optical cavity, resolving the issue of blue tint at the edges of sub-pixels.

[0130] FIG11A shows a cross-sectional view of a light-emitting element of a subpixel according to another embodiment of the present disclosure. The structure of the light-emitting element in FIG11A is similar to that in FIG10 , except that the structure of the first electrode is different. For ease of description, the following will focus on the differences.

[0131] As shown in FIG11A , the light-emitting element similarly includes a first electrode 207I, a second electrode 212I, and a transparent conductive layer 211 positioned between the first electrode 207I and the second electrode 212I. The first electrode 207I includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 positioned therebetween. The reflective layer L1 and transparent conductive layer L2 of the first electrode 207H have the same thickness in the central region 2071 and the edge region 2072 of the first electrode. The dielectric layer L3 of the first electrode 207H has different thicknesses in the central region 2071 and the edge region 2072 of the first electrode. Unlike FIG10 , the surface of the dielectric layer L3 of the first electrode 207I facing away from the substrate is substantially parallel to the substrate, and the dielectric layer L3 of the first electrode 207I is thicker in the central region 2071 than in the edge region 2072. This ensures that the cavity length h1 of the first optical cavity is greater than the cavity length h2 of the second optical cavity, thereby resolving the reddish cast at the sub-pixel edges.

[0132] In the above embodiment, a portion of the edge region of the first electrode is covered by the pixel defining layer. However, the embodiments of the present disclosure are not limited thereto. In some embodiments, the entire edge region of the first electrode is covered by the pixel defining layer. For example, as shown in FIG11B , similar to FIG11A , the light-emitting element also includes a first electrode 207I′, a second electrode 212I′, and a transparent conductive layer 211 located between the first electrode 207I′ and the second electrode 212I′, wherein the first electrode 207I′ includes a reflective layer L1, a transparent conductive layer L2, and a dielectric layer L3 located therebetween. The reflective layer L1 and the transparent conductive layer L2 of the first electrode 207H have the same thickness in the central region 2071 and the edge region 2072 of the first electrode, and the dielectric layer L3 of the first electrode 207H has different thicknesses in the central region 2071 and the edge region 2072 of the first electrode. Unlike FIG11A , the entire edge region 2072 of the first electrode 207I′ is covered by the pixel defining layer 209. The light-emitting unit of FIG11B can also achieve that the cavity length h1 of the first optical cavity is greater than the cavity length h2 of the second optical cavity, and can also solve the problem of reddish edges of sub-pixels.

[0133] FIG12 shows a schematic plan view of a first electrode of a sub-pixel according to an embodiment of the present disclosure.

[0134] As shown in Figure 12, the first electrode includes a central region 2071 and an edge region 2072 surrounding the central region. The description of the central region and the edge region in any of the above embodiments also applies to this embodiment. In some embodiments, the edge region 2072 of the first electrode can be configured to include multiple nested annular sub-regions, for example, sub-regions 2072_1 and 2072_2 as shown in Figure 12, wherein sub-region 2072_1 surrounds the central region 2071, and sub-region 2072_2 surrounds sub-region 2072_1. Of course, the number of sub-regions is not limited to this, and more annular sub-regions can be provided as needed. According to embodiments of the present disclosure, the film layer structure in adjacent sub-regions can be designed in a manner similar to the above-mentioned edge region and central region, thereby realizing different microcavity compensation structures in adjacent sub-regions. For example, at least one of the reflective layer, the transparent conductive layer, and the dielectric layer can have different thicknesses in adjacent annular sub-regions, so that the portion of the reflective layer located in each sub-region forms a sub-optical cavity with the second electrode, and the adjacent sub-optical cavities have different cavity lengths. As shown in Figure 12, adjacent sub-regions 2072_1 and 2072_2 correspond to two optical cavities, respectively. These two optical cavities can be implemented using the film layer structure of the edge region and the center region of any of the above-described embodiments, thereby achieving different cavity lengths. In some embodiments, the area of ​​the center region 2071 can be made larger than the areas of the individual annular sub-regions 2072_1 and 2072_2. Among the multiple annular sub-regions, the annular sub-regions closer to the center region 2071 have larger areas. For example, sub-region 2072_1 is closer to the center region 2071 than sub-region 2072_2, so the area of ​​sub-region 2072_1 is larger than the area of ​​sub-region 2072_2. For the outermost sub-region, the area of ​​the sub-region can be calculated based on the area of ​​the portion not covered by the pixel defining layer. In this way, the edge microcavity effect of silicon-based OLEDs can be compensated in a refined manner.

[0135] In some embodiments, the outer contours of the central area 2071 and each sub-area 2072_1 and 2072_2 are similar shapes, for example, all are hexagons in Figure 12. However, the embodiments of the present disclosure are not limited thereto, and the outer contours of the central area and each sub-area can be set to other shapes as needed.

[0136] FIG13 shows a plan view schematically illustrating sub-pixels of different colors according to an embodiment of the present disclosure.

[0137] According to an embodiment of the present disclosure, a plurality of sub-pixels in a display panel may include sub-pixels of different colors, such as a first sub-pixel Pxr, a second sub-pixel Pxg, and a third sub-pixel Pxb having different colors. In some embodiments, the first sub-pixel Pxr may be a red sub-pixel, the second sub-pixel Pxg may be a green sub-pixel, and the third sub-pixel Pxb may be a blue sub-pixel. However, the embodiments of the present disclosure are not limited thereto, and the colors of the sub-pixels in the display panel may be designed as needed. As shown in FIG. 13 , the first to third sub-pixels satisfy the following relationship: Src / Sr<Sgc / Sg<Sbc / Sb, and Sr<Sg<Sb (2)

[0138] Wherein Sr, Sg, and Sb represent the areas of the opening regions of the first subpixel Pxr, the second subpixel Pxg, and the third subpixel Pxb, respectively; Src, Sgc, and Sbc represent the areas of the center regions of the first electrodes of the first subpixel Pxr, the second subpixel Pxg, and the third subpixel Pxb, respectively.

[0139] With reference to the embodiments of FIG. 3 to FIG. 11B described above, the area of ​​the portion of the edge region of the first electrode of the sub-pixel that is not covered by the pixel defining layer can be defined as the compensation area. Then, the compensation area is the difference between the area of ​​the opening region and the area of ​​the central region of the first electrode. Since the smaller the sub-pixel area (i.e., the area of ​​the opening region), the more obvious the edge effect of the sub-pixel, by making the first to third sub-pixels satisfy the above-mentioned relationship (2), the area of ​​the central region of the sub-pixel with the more obvious edge effect is set to a smaller proportion, thereby increasing the proportion of the compensation area. This can further improve the display uniformity of the display panel.

[0140] In some embodiments, the area ratio of the central region to the opening region of the first to third sub-pixels can be further constrained to: 80%<Src / Sr<Sgc / Sg<Sbc / Sb<95%, thereby further improving the display uniformity of the display panel.

[0141] FIG. 14 shows a plan view schematically illustrating sub-pixels of the same color according to an embodiment of the present disclosure.

[0142] According to embodiments of the present disclosure, for subpixels of the same color, the area ratio of the center area to the opening area of ​​the first electrode of a subpixel located in the center region of the display panel can be different from the area ratio of the center area to the opening area of ​​the first electrode of a subpixel located in the edge region of the display panel. As shown in Figure 14, taking two green second subpixels as an example, second subpixel Pxg1 is closer to the center region of the display panel than second subpixel Pxg2. Therefore, the former can be considered to be located in the center region, while the latter is located in the edge region. The area of ​​the opening area of ​​second subpixel Pxg1 is Sg1, and the area of ​​the center area of ​​the first electrode is Sgc1; the area of ​​the opening area of ​​second subpixel Pxg2 is Sg2, and the area of ​​the center area of ​​the first electrode is Sgc2. For example, if the edge effect is more pronounced in the edge region of the display panel than in the center region, Sgc1 / Sg1>Sgc2 / Sg2 can be set, so that the compensation area ratio of subpixel Pxg2 in the edge region is greater than that of subpixel Pxg1 in the center region. Similarly, if the edge effect is more pronounced in the center region of the display panel, Sc1 / S1<Sc2 / S2 can be set.

[0143] The embodiments of the present disclosure improve the display uniformity of the central and edge areas of the display panel by designing the microcavity compensation area ratio of sub-pixels of the same color to be different in the central area and the edge area, thereby improving the display effect.

[0144] Figure 15A shows a schematic plan view of a sub-pixel according to one embodiment of the present disclosure. Figure 15B shows a schematic plan view of a sub-pixel according to another embodiment of the present disclosure.

[0145] As shown in Figures 15A and 15B , the sub-pixel may further include a via hole VIA for electrically connecting the first electrode to the source or drain of the driving transistor. The via hole VIA may be located inside the opening area of ​​the sub-pixel (as shown in Figure 15A ) or outside the opening area of ​​the sub-pixel (as shown in Figure 15B ).

[0146] As shown in FIG15A , a first distance d1 is defined between the edge of the central region 2071 of the first electrode facing the via hole VIA and the edge of the sub-pixel opening area OP, and a second distance d2 is defined between the edge of the central region 2071 of the first electrode facing away from the via hole VIA and the edge of the sub-pixel opening area OP. The second distance d2 is less than the first distance d1, i.e., d1>d2. Similarly, as shown in FIG15B , the distance d1' between the central region 2071 of the first electrode facing the via hole and the opening area OP and the distance d2' between the central region 2071 of the first electrode facing away from the via hole and the opening area OP also satisfy d1'>d2'.

[0147] Generally, the first electrode will be uneven near the via hole, resulting in a more severe edge effect. The embodiments of the present disclosure further improve the display uniformity of the sub-pixel area by setting the distance from the center area of ​​the first electrode near the via hole to the edge of the opening area to be greater than the distance from the center area of ​​the first electrode far from the via hole to the edge.

[0148] In some embodiments, when the via hole is located within the opening region of the sub-pixel, as shown in FIG15A , the first distance and the second distance have a first ratio d1 / d2. When the via hole is located outside the opening region of the sub-pixel, as shown in FIG15B , the first distance and the second distance have a second ratio d1' / d2'. The first ratio can be made greater than the second ratio, i.e., d1 / d2>d1' / d2'. Compared to when the via hole is located outside the opening region, the edge effect in the display area is more pronounced when the via hole is located within the opening region. By ensuring d1 / d2>d1' / d2', embodiments of the present disclosure can ensure display uniformity between sub-pixels with via holes located in different positions.

[0149] According to embodiments of the present disclosure, a microcavity compensation design similar to that used in the above-described embodiments for the opening region (i.e., the region not covered by the pixel-defining layer, also referred to as the display region) can also be employed in the non-display region (i.e., the region covered by the pixel-defining layer). This will be described in detail below with reference to Figures 16A to 16D.

[0150] FIG16A shows a cross-sectional view of a non-display region of a light-emitting element of a sub-pixel according to an embodiment of the present disclosure.

[0151] As shown in Figure 16A , the pixel defining layer 209 covers the edges of the first electrodes 207J of two adjacent sub-pixels. The pixel defining layer 209 may include a covering portion 2091 covering the first electrodes of adjacent sub-pixels and an uncovered portion 2092 located between the first electrodes of adjacent sub-pixels. As shown in Figure 16A , the reflective layers L1 of adjacent sub-pixels are continuous, forming a total reflective layer. The total reflective layer includes a first reflective portion L11 located within the opening area and a second reflective portion L12 located outside the opening area (i.e., in the non-display area). The second reflective portion L12 includes a first sub-portion L12a and second sub-portions L12b located on either side of the first sub-portion L12a. The projection of the first sub-portion L12a on the base substrate at least partially overlaps with the projection of the uncovered portion 2092 of the pixel defining layer 209 on the base substrate. The projection of the second sub-portion L12b on the base substrate at least partially overlaps with the projection of the covering portion 2091 of the pixel defining layer 209 on the base substrate.

[0152] For example, in the example of FIG16A , the surface of the non-covered portion 2092 of the pixel defining layer 209, away from the substrate, is lower than the surface of the covered portion 2091 of the pixel defining layer 209, away from the substrate. The surface of the first subportion L12a of the second reflective portion L12, away from the substrate, is lower than the surface of the second subportion L12b, away from the substrate. In some embodiments, the first subportion L12a and the second subportion L12b of the second reflective portion L12 can have the same thickness, and the surface of the first subportion L12a, closer to the substrate, is also lower than the surface of the second subportion L12b, closer to the substrate.

[0153] As shown in FIG16A , a first height difference Δreflect is formed between a surface of the first sub-portion L12a of the second reflective portion L12 and a surface of the second sub-portion L12b on a side away from the substrate. A second height difference ΔDpdl is formed between a surface of the covering portion 2091 of the pixel defining layer 209 and a surface of the uncovered portion 2092 of the pixel defining layer 209 on a side away from the substrate. The difference between the first height difference Δreflect and the second height difference ΔDpdl is within a preset range. For example, the first height difference Δreflect and the second height difference ΔDpdl may satisfy the following relationship: |ΔDpdl-Δreflect| / Δreflect<5% (3)

[0154] Wherein Δreflect represents the first height difference, and ΔDpdl represents the second height difference.

[0155] The pixel definition layer in the non-display area is also one of the important factors causing the edge effect. The embodiment of the present disclosure can effectively eliminate the influence of the microcavity difference caused by the edge effect on the display uniformity by maintaining the height difference Δreflect between the upper surface of the reflective layer in the central area and the non-display area and the height difference change deviation ΔDpdl between the upper surface of the pixel definition layer within a certain range.

[0156] In the embodiments disclosed herein, a concave-convex structure roughly identical to that of the pixel definition layer can be provided on the inorganic layer below the reflective layer. This ensures a consistent thickness of the reflective layer, allowing the reflective layer to be fabricated in a single process and improving reflectivity uniformity. Alternatively, the reflective layer can be provided with varying thicknesses to ensure that the reflective layer surface is consistent with the pixel definition layer.

[0157] For example, in Figure 16B, the side of the covering portion 2091 of the pixel defining layer 209 facing the non-covering portion may have an undercut structure, the thickness of the first sub-portion L12a of the second reflecting portion L12 is less than the thickness of the second sub-portion L12b, and the surface of the first sub-portion L11 close to the substrate side is basically flush with the surface of the second sub-portion L12 close to the substrate side, so that the second reflecting portion L12 maintains a basically consistent concave-convex structure with the pixel definition layer above.

[0158] In Figure 16C , the pixel definition layer 209 is designed with grooves cut into the planar layer 206. The surface of the uncovered portion 2092 of the pixel definition layer 209, away from the substrate, is lower than the surface of the transparent conductive layer L2 of the first electrode 207J, closer to the substrate. The surface of the first sub-portion L12a of the second reflective portion L12, away from the substrate, is lower than the surface of the second sub-portion L12b, away from the substrate. "Lower" here means a smaller distance relative to the substrate. The surface of the first sub-portion L12a, closer to the substrate, is substantially flush with the surface of the second sub-portion L12b, closer to the substrate. This ensures that the second reflective portion L12 maintains a substantially consistent concave-convex structure with the pixel definition layer above it.

[0159] In Figure 16D , the pixel definition layer has a columnar structure. The surface of the uncovered portion 2092 of the pixel definition layer 209, facing away from the substrate, is higher than the surface of the covered portion 2091 of the pixel definition layer 209, facing away from the substrate. The surface of the first sub-portion L12a of the second reflective portion L12, facing away from the substrate, is higher than the surface of the second sub-portion L12b, facing away from the substrate. The first sub-portion L12a and the second sub-portion L12b, facing closer to the substrate, can be substantially flush. In this way, the second reflective portion L12 maintains a substantially consistent concave-convex structure with the pixel definition layer above it.

[0160] The embodiments of the present disclosure provide complementary designs for corresponding areas of the reflective layer for different pixel definition layer structures, so that the surface of the reflective layer maintains consistent undulations with that of the pixel definition layer, thereby reducing the influence of edge effects on the microcavity effect and improving display uniformity.

[0161] An embodiment of the present disclosure further provides a display device, comprising the display panel of any of the above embodiments.

[0162] The display device according to the embodiment of the present disclosure may be an electronic device with a display function. For example, but not limited to, a smart phone, a mobile phone, a video phone, an e-book reader, a desktop computer (PC), a laptop PC, a netbook PC, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital audio player, a mobile medical device, a camera, a wearable device (such as a head-mounted device, an electronic clothing, an electronic bracelet, an electronic necklace, an electronic accessory, an electronic tattoo, or a smart watch), etc. The display device according to the embodiment of the present disclosure may also be an AR / VR display device, such as a helmet display, a stereo display mirror, and a glasses-type display, etc. The display device according to the embodiment of the present disclosure may also be a near-eye device that replaces an optical structure with a digital display, such as professional equipment such as an electronic telescope, an electronic microscope, and a medical endoscope that have similar near-eye display requirements.

[0163] The electronic device according to the embodiments of the present disclosure may also be a smart home appliance including a display function. For example, the smart home appliance may be a television, a digital video disc (DVD) player, a stereo, a refrigerator, an air conditioner, a vacuum cleaner, an oven, a microwave oven, a washing machine, a dryer, an air purifier, a set-top box, a television (TV) box, a game console, an electronic dictionary, an electronic key, a video camera, an electronic photo frame, etc.

[0164] The electronic device according to the embodiments of the present disclosure may also be a medical device (for example, a magnetic resonance angiography (MRA) device, a magnetic resonance imaging (MRI) device, a tomography (CT) device, an imaging device, or an ultrasound device), a navigation device, a global positioning system (GPS) receiver, an event data recorder (EDR), a flight data recorder (FDR), an automotive infotainment device, a marine electronic device (for example, a marine navigation device, a gyroscope, or a compass), an avionics device, a security device, an industrial or consumer robot, an automatic teller machine (ATM), a point of sale (POS), etc.

[0165] The electronic device according to the embodiments of the present disclosure may also be furniture including a display function, a part of a building / structure, an electronic bulletin board, an electronic signature receiving device, a projector, a variety of measuring devices (e.g., a water meter, an electricity meter, a gas meter, or an electromagnetic wave measuring device), etc. The electronic device according to some embodiments may be any combination of the aforementioned devices. In addition, the electronic device according to various embodiments may be a flexible device. In addition, it should be clear to those skilled in the art that the electronic device according to various embodiments of the present disclosure is not limited to the aforementioned devices.

[0166] Although the above embodiments illustrate the layout and layer structure of sub-pixels in a display panel using a specific layer structure as an example, the embodiments of the present disclosure are not limited thereto. The sub-pixels in a display panel can be distributed in any suitable manner as needed, and each sub-pixel can have another layer structure as needed, as long as the driving transistor of the sub-pixel can drive the light-emitting element to emit light.

Claims

1. A display panel comprising a substrate and a plurality of sub-pixels arranged on the substrate, wherein the sub-pixels include: A driving transistor, located on the substrate, the driving transistor having a gate, a source and a drain; a light emitting element, located at a side of the driving transistor away from the substrate, the light emitting element comprising a first electrode, a second electrode and a light emitting material layer between the first electrode and the second electrode, wherein the first electrode is electrically connected to a source or a drain of the driving transistor, and the first electrode comprises a central region and an edge region surrounding the central region; as well as a pixel defining layer, wherein the pixel defining layer covers a portion of an edge region of the first electrode; The first electrode includes a reflective layer, a transparent conductive layer, and a dielectric layer located between the reflective layer and the transparent conductive layer; a portion of the reflective layer located in the central region forms a first optical cavity with the second electrode; a portion of the reflective layer located in the edge region forms a second optical cavity with the second electrode; At least one of the reflective layer, the transparent conductive layer and the dielectric layer has different thicknesses in the central area and the edge area, so that the cavity length of the first optical cavity is different from the cavity length of the second optical cavity.

2. The display panel according to claim 1, in, The reflective layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and at least one of the transparent conductive layer and the dielectric layer of the first electrode has different thickness in the central region and the edge region of the first electrode; A surface of the second electrode facing the first electrode has a protrusion or a depression, and a projection of the protrusion or the depression on the base substrate at least partially overlaps with a projection of a central area of ​​the first electrode on the base substrate.

3. The display panel according to claim 2, in, The transparent conductive layer of the first electrode has the same thickness in the central area and the edge area of ​​the first electrode, and the dielectric layer of the first electrode has different thicknesses in the central area and the edge area of ​​the first electrode.

4. The display panel according to claim 3, in, A surface of the dielectric layer of the first electrode facing the substrate is substantially parallel to the substrate, a thickness of the dielectric layer of the first electrode in a central region is smaller than a thickness in an edge region, and a surface of the second electrode facing the first electrode has a protrusion, so that a cavity length of the first optical cavity is smaller than a cavity length of the second optical cavity.

5. The display panel according to claim 3, in, A surface of the dielectric layer of the first electrode facing the substrate is substantially parallel to the substrate, a thickness of the dielectric layer of the first electrode in a central region is greater than a thickness in an edge region, and a surface of the second electrode facing the first electrode has a depression, so that a cavity length of the first optical cavity is greater than a cavity length of the second optical cavity.

6. The display panel according to claim 2, in, The dielectric layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the transparent conductive layer of the first electrode has different thicknesses in the central region and the edge region of the first electrode.

7. The display panel according to claim 6, in, A surface of the transparent conductive layer of the first electrode facing the substrate is substantially parallel to the substrate, a thickness of the transparent conductive layer of the first electrode in a central region is smaller than a thickness in an edge region, a surface of the second electrode facing the first electrode has a protrusion, and a cavity length of the first optical cavity is smaller than a cavity length of the second optical cavity.

8. The display panel according to claim 6, in, A surface of the transparent conductive layer of the first electrode facing the substrate is substantially parallel to the substrate, a thickness of the transparent conductive layer of the first electrode in a central region is greater than a thickness in an edge region, a surface of the second electrode facing the first electrode has a depression, and a cavity length of the first optical cavity is greater than a cavity length of the second optical cavity.

9. The display panel according to claim 1, in, The transparent conductive layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the thickness of at least one of the reflective layer and the dielectric layer of the first electrode is different in the central region and the edge region of the first electrode; A surface of the second electrode facing the first electrode is substantially parallel to the base substrate.

10. The display panel according to claim 9, in, The reflective layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the dielectric layer of the first electrode has different thicknesses in the central region and the edge region of the first electrode.

11. The display panel according to claim 10, in, The surface of the dielectric layer of the first electrode away from the substrate is substantially parallel to the substrate, the thickness of the dielectric layer of the first electrode in the central region is smaller than that in the edge region, and the cavity length of the first optical cavity is smaller than that of the second optical cavity.

12. The display panel according to claim 10, in, The surface of the dielectric layer of the first electrode away from the substrate is substantially parallel to the substrate, the dielectric layer of the first electrode is thicker in the central region than in the edge region, and the cavity length of the first optical cavity is longer than that of the second optical cavity.

13. The display panel according to claim 9, in, The thickness of the reflective layer of the first electrode is different in the central area and the edge area of ​​the first electrode, the thickness of the dielectric layer of the first electrode is different in the central area and the edge area of ​​the first electrode, and the sum of the thickness of the reflective layer and the dielectric layer of the first electrode is basically the same in the central area and the edge area of ​​the first electrode.

14. The display panel according to claim 13, in, The surface of the dielectric layer of the first electrode away from the substrate and the surface of the reflective layer facing the substrate are both substantially parallel to the substrate, the thickness of the dielectric layer of the first electrode in the central region is smaller than that in the edge region, and the thickness of the reflective layer of the first electrode in the central region is larger than that in the edge region.

15. The display panel according to claim 13, in, A surface of the dielectric layer of the first electrode away from the substrate and a surface of the reflective layer facing the substrate are both substantially parallel to the substrate, a thickness of the dielectric layer of the first electrode in a central region is greater than a thickness in an edge region, and a thickness of the reflective layer of the first electrode in a central region is less than a thickness in an edge region.

16. The display panel according to any one of claims 1 to 15, in, The dielectric layer includes a first material located in a central region of the first electrode and a second material located in an edge region of the first electrode, and the first material and the second material have different etching rates.

17. The display panel according to claim 16, in, One of the first material and the second material is SiNx, and the other is SiOx.

18. The display panel according to any one of claims 1 to 17, in, The equivalent refractive index of each film layer in the first optical cavity is different from the equivalent refractive index of each film layer in the second optical cavity.

19. The display panel according to any one of claims 1 to 18, in, The first optical cavity and the second optical cavity satisfy the following conditions: Wherein, h1 represents the cavity length of the first optical cavity, h2 represents the cavity length of the second optical cavity, n is a positive integer, λ represents the central wavelength of light emitted by the sub-pixel, N1 represents the equivalent refractive index of each film layer in the first optical cavity, and N2 represents the equivalent refractive index of each film layer in the second optical cavity.

20. The display panel according to any one of claims 1 to 19, in, The edge region of the first electrode includes a plurality of nested annular sub-regions, and at least one of the reflective layer, the transparent conductive layer and the dielectric layer has different thicknesses in adjacent annular sub-regions, so that a portion of the reflective layer located in each sub-region forms a sub-optical cavity with the second electrode, respectively, and adjacent sub-optical cavities have different cavity lengths.

21. The display panel according to claim 18, in, The area of ​​the central region is larger than the areas of each annular sub-region, and among the plurality of annular sub-regions, the annular sub-region closer to the central region has a larger area.

22. The display panel according to claim 1, in, The plurality of sub-pixels include a first sub-pixel, a second sub-pixel, and a third sub-pixel, wherein the colors of the first sub-pixel, the second sub-pixel, and the third sub-pixel are different from each other. Among them, Src / Sr<Sgc / Sg<Sbc / Sb, and Sr<Sg<Sb, Wherein Sr, Sg, Sb represent the areas of the opening regions of the first sub-pixel, the second sub-pixel and the third sub-pixel respectively, Src, Sgc and Sbc represent the areas of the central regions of the first electrodes of the first sub-pixel, the second sub-pixel and the third sub-pixel respectively, wherein the opening region is the region of the first electrode not covered by the pixel defining layer.

23. The display panel according to claim 22, in, 80%<Src / Sr<Sgc / Sg<Sbc / Sb<95%.

24. The display panel according to any one of claims 1 to 23, in, Among sub-pixels of the same color, an area ratio of a central area of ​​the first electrode to the opening area of ​​a sub-pixel located in the central area of ​​the display panel is different from an area ratio of a central area of ​​the first electrode to the opening area of ​​a sub-pixel located in the central area of ​​the display panel.

25. The display panel according to any one of claims 1 to 24, in, The edge area of ​​the first electrode includes a first edge area covered by the pixel defining layer and a second edge area not covered by the pixel defining layer, wherein the thickness of at least one of the reflective layer, the transparent conductive layer and the dielectric layer in the central area is different from the thickness in the first edge area and the second edge area.

26. The display panel according to any one of claims 1 to 24, in, The edge area of ​​the first electrode includes a first edge area covered by the pixel defining layer and a second edge area not covered by the pixel defining layer, wherein at least one of the reflective layer, the transparent conductive layer and the dielectric layer has a thickness in the central area that is different from a thickness in the second edge area.

27. The display panel according to any one of claims 1 to 26, in, The sub-pixel further includes a via hole for electrically connecting the first electrode to the source or drain of the driving transistor, There is a first distance between an edge of a central region of the first electrode facing the via hole and an edge of an opening region of the sub-pixel; There is a second distance between an edge of a central region of the first electrode away from the via hole and an edge of an opening region of the sub-pixel, and the second distance is smaller than the first distance.

28. The display panel according to claim 27, in, When the via hole is located inside the opening area of ​​the sub-pixel, the first distance and the second distance have a first ratio; when the via hole is located outside the opening area of ​​the sub-pixel, the first distance and the second distance have a second ratio, wherein the first ratio is greater than the second ratio.

29. The display panel according to any one of claims 1 to 28, in, The pixel defining layer includes a covering portion covering the first electrodes of adjacent sub-pixels and a non-covering portion located between the first electrodes of adjacent sub-pixels; The reflection layers of adjacent sub-pixels are continuous to form a total reflection layer, wherein the total reflection layer includes a first reflection portion located in the opening area and a second reflection portion located outside the opening area, wherein the second reflection portion has a first sub-portion and a second sub-portion located on both sides of the first sub-portion, wherein a projection of the first sub-portion on the base substrate at least partially overlaps with a projection of the non-covered portion of the pixel defining layer on the base substrate, and a projection of the second sub-portion on the base substrate at least partially overlaps with a projection of the covered portion of the pixel defining layer on the base substrate; Among them, a surface of the first subpart of the second reflecting part away from the substrate side and a surface of the second subpart away from the substrate side have a first height difference, and a surface of the covering part of the pixel defining layer away from the substrate side and a surface of the non-covering part of the pixel defining layer away from the substrate side have a second height difference, wherein the difference between the first height difference and the second height difference is within a preset range.

30. The display panel according to claim 29, in, |ΔDpdl-Δreflect| / Δreflect<5%, Wherein Δreflect represents the first height difference, and ΔDpdl represents the second height difference.

31. The display panel according to claim 29 or 30, in, The surface of the non-covered portion of the pixel defining layer away from the substrate is lower than the surface of the covered portion of the pixel defining layer away from the substrate; A surface of the first sub-portion of the second reflective portion away from the substrate is lower than a surface of the second sub-portion away from the substrate.

32. The display panel according to claim 31, in, The first sub-portion and the second sub-portion have the same thickness, and a surface of the first sub-portion close to the substrate is lower than a surface of the second sub-portion close to the substrate.

33. The display panel according to claim 31, in, The side of the covering portion of the pixel defining layer facing the non-covering portion has an undercut structure; The thickness of the first sub-portion of the second reflective portion is smaller than that of the second sub-portion, and the surface of the first sub-portion close to the substrate is substantially flush with the surface of the second sub-portion close to the substrate.

34. The display panel according to claim 31, in, The surface of the non-covered portion of the pixel defining layer away from the base substrate is lower than the surface of the transparent conductive layer of the first electrode close to the base substrate; The surface of the first sub-part away from the substrate is lower than the surface of the second sub-part away from the substrate, and the surface of the first sub-part close to the substrate is substantially flush with the surface of the second sub-part close to the substrate.

35. The display panel according to claim 29 or 30, in, The surface of the non-covered portion of the pixel defining layer away from the substrate is higher than the covering portion of the pixel defining layer. The part is away from the surface of the substrate side; A surface of the first sub-portion of the second reflective portion away from the substrate is higher than a surface of the second sub-portion away from the substrate.

36. A display panel comprising a substrate and a plurality of sub-pixels arranged on the substrate, wherein the sub-pixels include: A driving transistor, located on the substrate, the driving transistor having a gate, a source and a drain; a light emitting element, located at a side of the driving transistor away from the substrate, the light emitting element comprising a first electrode, a second electrode and a light emitting material layer between the first electrode and the second electrode, wherein the first electrode is electrically connected to a source or a drain of the driving transistor, and the first electrode comprises a central region and an edge region surrounding the central region; as well as a pixel defining layer, wherein the pixel defining layer covers at least a portion of an edge region of the first electrode; The first electrode includes a reflective layer, a transparent conductive layer, and a dielectric layer located between the reflective layer and the transparent conductive layer; a portion of the reflective layer located in the central region forms a first optical cavity with the second electrode; a portion of the reflective layer located in the edge region forms a second optical cavity with the second electrode; Wherein, the output light of the first optical cavity has a first central wavelength λ1, and the output light of the second optical cavity has a second central wavelength λ2; At least one of the reflective layer, the transparent conductive layer and the dielectric layer has different thicknesses in the central region and the edge region, so that a relative deviation value of |1-λ1 / λ2| between the first central wavelength λ1 and the second central wavelength λ2 is less than 5%.

37. The display panel according to claim 36, in, The pixel defining layer covers the entire edge region of the first electrode, and at least one of the reflective layer, the transparent conductive layer and the dielectric layer has a thickness in the central region that is different from a thickness in the entire edge region.

38. The display panel according to claim 36 or 37, in, The reflective layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and at least one of the transparent conductive layer and the dielectric layer of the first electrode has different thickness in the central region and the edge region of the first electrode; A surface of the second electrode facing the first electrode has a protrusion or a depression, and a projection of the protrusion or the depression on the base substrate at least partially overlaps with a projection of a central area of ​​the first electrode on the base substrate.

39. The display panel according to claim 36 or 37, in, The transparent conductive layer of the first electrode has the same thickness in the central region and the edge region of the first electrode, and the thickness of at least one of the reflective layer and the dielectric layer of the first electrode is different in the central region and the edge region of the first electrode; A surface of the second electrode facing the first electrode is substantially parallel to the base substrate.

40. A display device comprising the display panel according to any one of claims 1 to 39.

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