Scoreboard and display device

Abstract

Display panel comprising: a substrate; and a luminescent component layer arranged on one side of the substrate, comprising: an anode layer arranged on one side of the substrate; a first electron blocking layer arranged on a side of the anode layer facing away from the substrate, comprising a first electron blocking unit and a second electron blocking unit, wherein a ratio of a thickness of the second electron blocking unit to a thickness of the first electron blocking unit is a first ratio and the first ratio is less than 2;a first phosphor layer arranged on a side of the first electron blocking layer facing away from the anode layer and comprising a first blue phosphor unit and a first green phosphor unit, wherein an orthogonal projection of the first blue phosphor unit onto the substrate overlaps with an orthogonal projection of the first electron blocking unit onto the substrate, and an orthogonal projection of the first green phosphor unit onto the substrate overlaps with an orthogonal projection of the second electron blocking unit onto the substrate; a charge generation layer arranged on a side of the first phosphor layer facing away from the first electron blocking layer; a second phosphor layer arranged on a side of the charge generation layer facing away from the first phosphor layer; and a cathode layer arranged on a side of the second phosphor layer facing away from the charge generation layer.

Description

Display panel and display device TECHNICAL FIELD

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

[0002] With the development of flat panel display technology, customers' requirements for the stability of display gradually increase. In recent years, the organic light emitting diode (OLED) display develops rapidly in the world, and the OLED display technology is increasingly refined. Under such circumstances, the application demand of stacked OLED devices increases, and major display manufacturers also invest resources in technology and product development, and launch various structures of stacked devices. At present, the mainstream stacked OLED device structure is complex, and the manufacturing cost is high, so how to reduce the cost of the stacked OLED device is very important. TECHNICAL PROBLEM

[0003] The present application provides a display panel and a display device, which are beneficial to reduce the manufacturing cost of the display panel. TECHNICAL SOLUTION

[0004] In a first aspect, the present application provides a display panel. The display panel comprises a substrate and a light emitting device layer. The light emitting device layer is located on one side of the substrate. The light emitting device layer comprises an anode layer, a first electron blocking layer, a first light emitting layer, a charge generation layer, a second light emitting layer and a cathode layer. The anode layer is located on one side of the substrate. The first electron blocking layer is located on a side of the anode layer away from the substrate, and comprises a first electron blocking unit and a second electron blocking unit, a thickness of the second electron blocking unit divided by a thickness of the first electron blocking unit is a first ratio, and the first ratio is less than 2. The first light emitting layer is located on a side of the first electron blocking layer away from the anode layer, and comprises a first blue light emitting unit and a first green light emitting unit. A normal projection of the first blue light emitting unit on the substrate overlaps a normal projection of the first electron blocking unit on the substrate. A normal projection of the first green light emitting unit on the substrate overlaps a normal projection of the second electron blocking unit on the substrate. The charge generation layer is located on a side of the first light emitting layer away from the first electron blocking layer. The second light emitting layer is located on a side of the charge generation layer away from the first light emitting layer. The cathode layer is located on a side of the second light emitting layer away from the charge generation layer.

[0005] In a second aspect, the present application further provides a display device, which comprises the above display panel. ADVANTAGEOUS EFFECTS

[0006] In some embodiments of the display panel and the display device, the first blue light emitting unit is overlapped with the first electron blocking unit on the substrate. The first green light emitting unit is overlapped with the second electron blocking unit on the substrate. The ratio of the thickness of the second electron blocking unit to the thickness of the first electron blocking unit is a first ratio, and the first ratio is less than 2. In this way, the thickness of the second electron blocking unit overlapped with the first green light emitting unit is thinner, which is conducive to reducing the evaporation rate of the material forming the second electron blocking unit, so that the material of the second electron blocking unit and the material of the first green light emitting unit are placed in one evaporation chamber and share one mask plate for evaporation, thereby reducing the manufacturing cost of the display panel and the display device. BRIEF DESCRIPTION OF DRAWINGS

[0007] FIG. 1 is a schematic diagram of a cross-sectional structure of a display panel according to some embodiments of the present application;

[0008] FIG. 2 is a schematic diagram of a cross-sectional structure of a display panel according to some other embodiments of the present application;

[0009] FIG. 3 is a schematic diagram of a cross-sectional structure of a display panel according to some other embodiments of the present application;

[0010] FIG. 4 is a structural block diagram of a display device according to some embodiments of the present application.

[0011] The following signs are used in the specification:

[0012] 100, display panel; 200, display device;

[0013] 111, substrate; 112, driving circuit layer;

[0014] 12, light emitting device layer;

[0015] 13, anode layer;

[0016] 14, first light emitting stack;

[0017] 141, first electron blocking layer; 1411, first electron blocking unit; 1412, second electron blocking unit; 1413, third electron blocking unit;

[0018] 142, first light emitting layer; 1421, first blue light emitting unit; 1422, first green light emitting unit; 1423, first red light emitting unit;

[0019] 143, hole injection layer; 144, first hole transport layer; 145, first hole blocking layer; 146, first electron transport layer;

[0020] 15, charge generation layer; 151, n-type charge generation layer; 152, p-type charge generation layer;

[0021] 16, second light-emitting stack;

[0022] 161, second electron blocking layer; 1611, fourth electron blocking unit; 1612, fifth electron blocking unit; 1613, sixth electron blocking unit;

[0023] 162, second light-emitting layer; 1621, second blue light-emitting unit; 1622, second green light-emitting unit; 1623, second red light-emitting unit;

[0024] 163, second hole transport layer; 164, second hole blocking layer; 165, second electron transport layer; 166, electron injection layer;

[0025] 17, cathode layer;

[0026] 18, cover layer;

[0027] 191, first intermediate transport layer; 192, second intermediate transport layer. Embodiments of the present application

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] As shown in FIGS. 1-3, the present application provides a display panel 100. The display panel 100 is an organic light-emitting diode display panel. The display panel 100 includes a substrate 111 and a light-emitting device layer 12. The light-emitting device layer 12 is located on one side of the substrate 111. The light-emitting device layer 12 includes an anode layer 13, a first light-emitting stack 14, a charge generation layer 15, a second light-emitting stack 16, and a cathode layer 17. The first light-emitting stack 14 is a bottom light-emitting stack, and the second light-emitting stack 16 is a top light-emitting stack. It can be understood that the light-emitting device layer 12 can include three or more light-emitting stacks, and a charge generation layer 15 is arranged between any two adjacent light-emitting stacks.

[0030] The anode layer 13 is located on one side of the substrate 111. The anode layer 13 can include a first light-transmitting anode layer and a first reflective anode layer stacked. The first light-transmitting anode layer is located between the first reflective anode layer and the substrate 111. The anode layer 13 can further include a second light-transmitting anode layer, which is located on the side of the first reflective anode layer away from the first light-transmitting anode layer. The first light-transmitting anode layer and the second light-transmitting anode layer can include transparent conductive material. The first reflective anode layer can include a metal material such as silver.

[0031] The first light-emitting stack 14 comprises a first electron-blocking layer 141 and a first light-emitting layer 142.

[0032] The first electron-blocking layer 141 blocks electrons. The first electron-blocking layer 141 is located on the side of the anode layer 13 away from the substrate 111. The first electron-blocking layer 141 comprises a first electron-blocking unit 1411 and a second electron-blocking unit 1412.

[0033] The first light-emitting layer 142 is located on the side of the first electron-blocking layer 141 away from the anode layer 13. The first light-emitting layer 142 comprises a first blue light-emitting unit 1421 and a first green light-emitting unit 1422.

[0034] The first blue light-emitting unit 1421 overlaps the first electron-blocking unit 1411 in projection on the substrate 111, that is, the first electron-blocking unit 1411 plays a role of blocking electrons in the first blue light-emitting device of the first light-emitting stack 14. The first blue light-emitting unit 1421 and the first electron-blocking unit 1411 are stacked and directly contact each other.

[0035] The first green light-emitting unit 1422 overlaps the second electron-blocking unit 1412 in projection on the substrate 111, that is, the second electron-blocking unit 1412 plays a role of blocking electrons in the first green light-emitting device of the first light-emitting stack 14. The first green light-emitting unit 1422 and the second electron-blocking unit 1412 are stacked and directly contact each other.

[0036] The ratio of the thickness of the second electron-blocking unit 1412 to the thickness of the first electron-blocking unit 1411 is a first ratio, and the first ratio is less than 2. In this way, the thickness of the second electron-blocking unit 1412 overlapping the first green light-emitting unit 1422 is thin, which is conducive to reducing the evaporation rate of the material forming the second electron-blocking unit 1412. After the evaporation of the second electron-blocking unit 1412 is completed, the evaporation process of the material forming the second electron-blocking unit 1412 does not stop, and the evaporated material will accumulate on the shutter plate closed. A lower evaporation rate is sufficient to extend the failure time of the shutter plate to the next production. Therefore, in terms of process, a lower evaporation rate is conducive to placing the material of the second electron-blocking unit 1412 and the material of the first green light-emitting unit 1422 in one evaporation chamber and sharing one mask plate. Compared with the related art, which requires two mask plates to manufacture the second electron-blocking unit 1412 and the first green light-emitting unit 1422, the technical solution of the present application can reduce one mask plate, thereby reducing the manufacturing cost of the display panel 100.

[0037] It should be noted that the applicant of the present application has found, based on a large amount of practical experience, that when the evaporation machine evaporates a certain material, the shutter corresponding to the evaporation of other materials on the evaporation machine needs to be closed to avoid the evaporation of other materials onto the target substrate. When the shutter closes the gate, the evaporation process of other materials does not stop, and the evaporated other materials will accumulate on the shutter. Too much other material will accumulate on the shutter, and to a certain extent, the shutter will fail. Based on this, the present application reduces the thickness of the second electron blocking unit 1412 overlapping the first green light emitting unit 1422, which is conducive to reducing the evaporation rate of the material forming the second electron blocking unit 1412. When the material of the second electron blocking unit 1412 and the material of the first green light emitting unit 1422 are placed in one evaporation chamber and share one mask plate for evaporation, the risk of failure of the shutter that blocks the evaporation material of the second electron blocking unit 1412 is reduced. It should also be noted that in the present application, the thickness of the second electron blocking unit 1412 is equal to the size of the second electron blocking unit 1412 in the direction in which the substrate 111 points to the light emitting device layer 12. Similarly, the thickness of the first electron blocking unit 1411 is equal to the size of the first electron blocking unit 1411 in the direction in which the substrate 111 points to the light emitting device layer 12. Other thicknesses in the following are also the sizes in the direction in which the substrate 111 points to the light emitting device layer 12.

[0038] In related technologies, the first electron blocking layer not only blocks electrons, but also serves as a microcavity adjustment layer. Therefore, adjusting the thickness of the first electron blocking layer can adjust the size of the microcavity corresponding to the first light emitting layer 142. In order to make the structural size of the microcavity corresponding to the first green light emitting unit optimal and improve the light extraction efficiency of the first green light emitting unit, the thickness of the second electron blocking unit is usually thick.

[0039] In some embodiments, the first ratio can be greater than or equal to 0.5 and less than or equal to 1.8. In this way, the evaporation process of the second electron blocking unit 1412 and the first green light emitting unit 1422 can be carried out under the same mask plate, thereby reducing the number of mask plates needed while reducing the difficulty of monitoring the thickness of the second electron blocking unit 1412, improving the controllability of the thickness of the second electron blocking unit 1412, and thus ensuring the function of the second electron blocking unit 1412.

[0040] In some embodiments, the first ratio can be greater than or equal to 0.8 and less than or equal to 1.2. In this way, the evaporation process of the second electron blocking unit 1412 and the first green light emitting unit 1422 can be performed under the same mask plate, so as to reduce the number of mask plates to be used, further reduce the difficulty of monitoring the thickness of the second electron blocking unit 1412, improve the controllability of the thickness of the second electron blocking unit 1412, and thus ensure the function of the second electron blocking unit 1412.

[0041] In some embodiments, the first ratio can be 1, in which case the thickness of the second electron blocking unit 1412 is equal to the thickness of the first electron blocking unit 1411. It should be noted that when the thickness of the second electron blocking unit 1412 is equal to the thickness of the first electron blocking unit 1411, the thickness deviation within ±10% range caused by process reasons also belongs to the case of equal thickness.

[0042] Alternatively, the first ratio can be greater than or equal to 0.6 and less than or equal to 1.7, or the first ratio can be greater than or equal to 0.7 and less than or equal to 1.5.

[0043] Exemplarily, the first ratio can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 1.95.

[0044] In some embodiments, the first electron blocking layer 141 further comprises a third electron blocking unit 1413. The first light emitting layer 142 further comprises a first red light emitting unit 1423. The orthographic projection of the first red light emitting unit 1423 on the substrate 111 overlaps with the orthographic projection of the third electron blocking unit 1413 on the substrate 111, that is, the third electron blocking unit 1413 plays a role of blocking electrons in the first red light emitting device of the first light emitting stack 14. The first red light emitting unit 1423 and the third electron blocking unit 1413 are stacked and directly contact each other.

[0045] The ratio of the thickness of the third electron blocking unit 1413 to the thickness of the first electron blocking unit 1411 is a second ratio. The ratio of the second ratio to the first ratio is greater than or equal to 0.5 and less than or equal to 6. In this way, the second ratio has a relatively large adjustable range, so that the thickness of the third electron blocking unit 1413 has a relatively large adjustable range to meet different performance requirements of the display panel 100.

[0046] In some embodiments, the ratio of the second ratio to the first ratio can be greater than or equal to 0.8 and less than or equal to 5.5, greater than or equal to 1.2 and less than or equal to 5, greater than or equal to 1.5 and less than or equal to 4.5, greater than or equal to 2 and less than or equal to 4, or greater than or equal to 2.2 and less than or equal to 3.5.

[0047] Exemplarily, the ratio of the second ratio to the first ratio can be 0.5, 0.7, 0.9, 1, 1.5, 1.7, 2.0, 2.5, 2.7, 3.0, 3.5, 3.7, 4.0, 4.5, 4.7, 5.0, 5.5, 5.7, or 6.0.

[0048] In some embodiments, the second ratio is less than 4. In this way, the thickness of the third electron blocking unit 1413 overlapping with the first red light emitting unit 1423 is thin, which is conducive to reducing the evaporation rate of the material forming the third electron blocking unit 1413. Moreover, after the evaporation of the third electron blocking unit 1413 is completed, the evaporation process of the material forming the third electron blocking unit 1413 does not stop, and the evaporated material will accumulate on the shutter closing the gate. A lower evaporation rate is sufficient to prolong the failure time of the shutter to the next production. Therefore, in terms of process, a lower evaporation rate is conducive to placing the material of the third electron blocking unit 1413 and the material of the first red light emitting unit 1423 in one evaporation chamber and sharing one mask plate. Compared with the related art, which requires two mask plates to manufacture the third electron blocking unit 1413 and the first red light emitting unit 1423, the technical solution of the present application can further reduce one mask plate, thereby reducing the manufacturing cost of the display panel 100.

[0049] It should be noted that, compared with the related art, the thickness of the third electron blocking unit 1413 is thinned in the present application, so that its evaporation process and the evaporation process of the first red light emitting unit 1423 can use one mask plate.

[0050] In some embodiments, the second ratio is greater than or equal to 0.8 and less than or equal to 1.2. In this way, the evaporation processes of the third electron blocking unit 1413 and the first red light emitting unit 1423 can be carried out under the same mask plate, so as to reduce the number of mask plates needed to be used, further reduce the difficulty of monitoring the thickness of the third electron blocking unit 1413, improve the controllability of the thickness of the third electron blocking unit 1413, and thus ensure the function of the third electron blocking unit 1413.

[0051] In some embodiments, the second ratio can be 1, i.e., the thickness of the third electron blocking unit 1413 is the same as that of the first electron blocking unit 1411. It should be noted that when the thickness of the third electron blocking unit 1413 is equal to that of the first electron blocking unit 1411, the thickness deviation within the range of ±10% caused by process reasons also belongs to the case of equal thickness.

[0052] Alternatively, the second ratio can be greater than or equal to 0.5 and less than or equal to 3.8, greater than or equal to 0.8 and less than or equal to 3.5, greater than or equal to 1.0 and less than or equal to 3.2, greater than or equal to 1.2 and less than 2.8, greater than or equal to 1.5 and less than or equal to 2.5, or greater than or equal to 1.8 and less than or equal to 2.2.

[0053] Exemplarily, the second ratio can be 0.5, 0.8, 1.0, 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.5, 3.8, or 4.0.

[0054] In combination with the above, the thickness of the second electron blocking unit 1412 and the third electron blocking unit 1413 of the first electron blocking layer 141 is thinned in the present application, so as to omit two mask plates required for forming the first light-emitting stack 14, thereby reducing the manufacturing cost of the display panel 100.

[0055] As shown in FIGS. 1-3, in some embodiments, the first light-emitting stack 14 further includes a first hole injection layer 143 (Hole Inject Layer, HIL), which is located between the anode layer 13 and the first electron blocking layer 141.

[0056] As shown in FIGS. 1-3, in some embodiments, the first light-emitting stack 14 further includes a first hole transport layer 144 (Hole Transport Layer, HTL), which is located between the hole injection layer 143 and the first electron blocking layer 141.

[0057] As shown in FIGS. 1-3, the charge generation layer 15 is located on the side of the first light-emitting layer 142 away from the first electron blocking layer 141. The charge generation layer 15 includes an n-type charge generation layer 151. The n-type charge generation layer 151 is used to generate n-type charges.

[0058] In some embodiments, the n-type charge generation layer 151 includes an n-type semiconductor host material and a first doping material to increase the electron mobility to enhance the carrier balance. The n-type semiconductor host material includes, but is not limited to, at least one of a pyridine derivative, a pyrimidine derivative, a triazine derivative, an imidazole derivative, an oxazole derivative, and a phenanthroline derivative. The first doping material includes, but is not limited to, at least one of ytterbium (Yb), Li, Cs, and Mg. The electron mobility of the n-type charge generation layer 151 is μ e ≥ 10 -3 cm 2 / Vs.

[0059] In some embodiments, the n-type semiconductor host material is selected from at least one compound having the general formula (1):

[0060] wherein X301 to X309 are each independently selected from C, N, a pyridyl group or a group having a pyridine derivative, a pyrimidyl group or a group having a pyrimidine derivative, a triazyl group or a group having a triazine derivative, an imidazyl group or a group having an imidazole derivative, an oxazyl group or a group having an oxazole derivative, and a phenanthrolinyl group or a group having a phenanthroline derivative.

[0061] In some embodiments, the n-type semiconductor host material is selected from at least one compound having the general formula (1):

[0062] In some embodiments, the first doping material has a doping mass percentage of 5% to 15% to enhance the carrier balance and improve the impact of thinning the thickness of the second and third electron blocking units 1412 and 1413 on the carrier balance.

[0063] As shown in FIGS. 1 to 3, in some embodiments, the display panel 100 further includes a first hole blocking layer 145 (HBL). The first hole blocking layer 145 is located between the n-type charge generation layer 151 and the first light emitting layer 142.

[0064] As shown in FIG. 1, in some embodiments, the display panel 100 further includes a first electron transport layer 146. The first electron transport layer 146 is located between the n-type charge generation layer 151 and the first hole blocking layer 145 and directly contacts the n-type charge generation layer 151 and the first hole blocking layer 145. In this way, the stability of the display panel 100 in transporting carriers is ensured, thereby improving the display effect of the display panel 100.

[0065] As shown in FIG. 2, in some embodiments, the display panel 100 further comprises a first hole blocking layer 145 (HBL) located between the n-type charge generation layer 151 and the first light emitting layer 142 and directly contacting the n-type charge generation layer 151. In this way, compared with the display panel 100 shown in FIG. 1, the display panel 100 shown in FIG. 2 removes the first electron transport layer 146 in the first light emitting stack 14, thereby omitting the mask plate for forming the first electron transport layer 146, and further reducing the manufacturing cost of the display panel 100. Moreover, compared with removing other film layers in the first light emitting stack 14 and the second light emitting stack 16 (for example, the film layers in the second light emitting stack 16 or other film layers in the first light emitting stack 14), removing the first electron transport layer 146 can maximally reduce the impact on the driving voltage, the light emitting efficiency and the service life, that is, maximally reduce the impact on the display panel 100.

[0066] As shown in FIG. 3, in some embodiments, the display panel 100 further comprises a first intermediate transport layer 191. The first intermediate transport layer 191 is located between the first hole blocking layer 145 and the n-type charge generation layer 151, directly contacts the n-type charge generation layer 151 and the first hole blocking layer 145, and comprises an n-type semiconductor host material. In this way, on the basis of removing the first electron transport layer 146, the first intermediate transport layer 191 is added. The first intermediate transport layer 191 comprises an n-type semiconductor host material having the ability to transport electrons, so that the first intermediate transport layer 191 replaces the first electron transport layer 146 to transport electrons, and ensures the performance of the display panel 100. Moreover, the material of the first intermediate transport layer 191 comprises the n-type semiconductor host material of the n-type charge generation layer 151, the angle plate for forming the n-type charge generation layer 151 can be adjusted, the n-type semiconductor host material is not completely co-evaporated with the first doping material, and the number of scans is not increased, so as to form the first intermediate transport layer 191, that is, the first intermediate transport layer 191 is formed by using the evaporation process and the mask plate for forming the n-type charge generation layer 151, without adding an additional mask plate. Therefore, in the case of omitting the mask plate for forming the first electron transport layer 146, the performance of the display panel 100 is improved.

[0067] As shown in FIGS. 1 to 3, the second light emitting stack 16 is located on the side of the charge generation layer 15 away from the first light emitting layer 142. The cathode layer 17 is located on the side of the second light emitting stack 16 away from the substrate 111. The second light emitting stack 16 further comprises a second hole blocking layer 164 and a second electron transport layer 165. The second hole blocking layer 164 plays a role of blocking holes in the second light emitting stack 16. The second electron transport layer 165 plays a role of transporting electrons in the second light emitting stack 16.

[0068] In some embodiments, the second hole blocking layer 164 is located between the second light emitting layer 162 and the cathode layer 17. The second electron transport layer 165 is located between the second hole blocking layer 164 and the cathode layer 17. The ratio of the thickness of the first intermediate transport layer 191 to the second electron transport layer 165 is greater than or equal to 0.05 and less than or equal to 0.15. In this way, the transport performance of the first intermediate transport layer 191 is ensured, and the difficulty of forming the angle plate of the n-type charge generation layer 151 to form the first intermediate transport layer 191 is reduced.

[0069] Optionally, the ratio of the thickness of the first intermediate transport layer 191 to the second electron transport layer 165 is greater than or equal to 0.08 and less than or equal to 0.14, or greater than or equal to 0.1 and less than or equal to 0.12.

[0070] Illustratively, the ratio of the thickness of the first intermediate transport layer 191 to the second electron transport layer 165 is 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, or 0.15.

[0071] As shown in FIGS. 1-3, the charge generation layer 15 further includes a p-type charge generation layer 152. The p-type charge generation layer 152 is used to generate p-type charges.

[0072] The p-type charge generation layer 152 includes a p-type semiconductor host material and a second dopant material to increase the hole mobility to enhance the balance of carriers. The second dopant material includes a metal or a metal dopant. The p-type semiconductor host material is typically composed of a metal oxide (e.g., ITO, WO3, MoO3, V2O5) or a hole transport material doped with a Lewis acid (e.g., FeCl3:NPB, F4-TCNQ:NPB).

[0073] In some embodiments, the n-type charge generation layer 151 is located between the p-type charge generation layer 152 and the first light emitting layer 142. The display panel 100 further includes a second intermediate transport layer 192. The second intermediate transport layer 192 is located between the p-type charge generation layer 152 and the n-type charge generation layer 151 and includes an n-type semiconductor host material. In this way, the second intermediate transport layer 192 is added between the n-type charge generation layer 151 and the p-type charge generation layer 152 to further enhance the balance of carriers. Moreover, the material of the second intermediate transport layer 192 includes the n-type semiconductor host material of the n-type charge generation layer 151, and the angle plate for forming the n-type charge generation layer 151 can be adjusted to form the second intermediate transport layer 192, i.e., the second intermediate transport layer 192 is formed by using the evaporation process and the mask plate for forming the n-type charge generation layer 151, without the need to add an additional mask plate. Therefore, the performance of the display panel 100 is improved without increasing the mask plate.

[0074] In some embodiments, the ratio of the thickness of the second intermediate transport layer 192 to the second electron transport layer 165 is greater than or equal to 0.05 and less than or equal to 0.15. In this way, the transport performance of the second intermediate transport layer 192 is ensured while reducing the process difficulty of adjusting the angle plate to form the n-type charge generation layer 151 to form the second intermediate transport layer 192.

[0075] Alternatively, the ratio of the thickness of the second intermediate transport layer 192 to the second electron transport layer 165 is greater than or equal to 0.08 and less than or equal to 0.14, or greater than or equal to 0.1 and less than or equal to 0.12.

[0076] Exemplarily, the ratio of the thickness of the second intermediate transport layer 192 to the second electron transport layer 165 is 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, or 0.15.

[0077] As shown in FIGS. 1-3, the second light-emitting stack 16 includes a second light-emitting layer 162 located on the side of the charge generation layer 15 away from the first light-emitting layer 142. The second light-emitting layer 162 includes a second blue light-emitting unit 1621 and a second green light-emitting unit 1622.

[0078] As shown in FIGS. 1-3, the second light-emitting stack 16 further includes a second electron blocking layer 161. The second electron blocking layer 161 is located between the charge generation layer 15 and the second light-emitting layer 162. The second electron blocking layer 161 functions to block electrons. The second electron blocking layer 161 includes a fourth electron blocking unit 1611 and a fifth electron blocking unit 1612.

[0079] The orthogonal projection of the second blue light-emitting unit 1621 on the substrate 111 overlaps the orthogonal projection of the first blue light-emitting unit 1421 and the fourth electron blocking unit 1611 on the substrate 111. The second blue light-emitting unit 1621 is superposed with and directly contacts the fourth electron blocking unit 1611. The first blue light-emitting unit 1421 is superposed with the second blue light-emitting unit 1621, and the fourth electron blocking unit 1611 functions to block electrons in the second blue light-emitting device.

[0080] The orthogonal projection of the second green light-emitting unit 1622 on the substrate 111 overlaps the orthogonal projection of the first green light-emitting unit 1422 and the fifth electron blocking unit 1612 on the substrate 111. The second green light-emitting unit 1622 is superposed with and directly contacts the fifth electron blocking unit 1612. The first green light-emitting unit 1422 is superposed with the second green light-emitting unit 1622, and the fifth electron blocking unit 1612 functions to block electrons in the second green light-emitting device.

[0081] In some embodiments, the ratio of the thickness of the fifth electron blocking unit 1612 to the thickness of the fourth electron blocking unit 1611 is a third ratio, and the third ratio is greater than the first ratio. In this way, the ratio of the thickness of the fifth electron blocking unit 1612 to the thickness of the fourth electron blocking unit 1611 is greater, and the thickness of the fifth electron blocking unit 1612 is increased to compensate for the thinning of the thickness of the second electron blocking unit 1412, to reduce the impact of the thinning of the thickness on the optimal microcavity size corresponding to the second green light emitting device, and to further improve the light extraction efficiency of the light emitted by the second green light emitting unit 1622.

[0082] It should be noted that the optimal microcavity size corresponding to each light emitting unit in the second light emitting layer 162 is related to the thickness of all film layers between the anode layer 13 and the cathode layer 17. Moreover, the second light emitting stack 16 is located on top of the light emitting device layer 12, and the light emitting efficiency of the second light emitting stack 16 is higher than that of the first light emitting stack 14. The microcavity structure design is adopted to improve the light extraction efficiency of the light emitted by the second green light emitting unit 1622 in the second light emitting stack 16, which can further display the display effect of the display panel 100. In addition, the wavelengths of blue light, green light and red light increase, so the sizes of the microcavity structures corresponding to the blue light, green light and red light also show an increasing trend.

[0083] In some embodiments, the ratio of the third ratio to the first ratio is greater than or equal to 4.5 and less than or equal to 6.5. In this way, the thickness of the fifth electron blocking unit 1612 is increased to a microcavity size corresponding to the second green light emitting device within a suitable size range, so as to maximize the light extraction efficiency of the green light emitted by the second green light emitting unit 1622.

[0084] Alternatively, the ratio of the third ratio to the first ratio is greater than or equal to 4.8 and less than or equal to 6, greater than or equal to 5 and less than or equal to 5.8, or greater than or equal to 5.2 and less than or equal to 5.6.

[0085] For example, the ratio of the third ratio to the first ratio is 4.5, 4.7, 4.9, 5.1, 5.3, 5.5, 5.7, 5.9 or 6.0.

[0086] In some embodiments, the third ratio is greater than or equal to 5 and less than or equal to 6. In this way, the ratio of the thickness of the fifth electron blocking unit 1612 to the thickness of the fourth electron blocking unit 1611 is within a suitable range, so that the thickness of the fifth electron blocking unit 1612 is increased to a microcavity size corresponding to the second green light emitting device within a suitable size range, so as to maximize the light extraction efficiency of the green light emitted by the second green light emitting unit 1622.

[0087] For example, the third ratio is 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9 or 6.0.

[0088] In some embodiments, the fifth electron blocking unit 1612 has a thickness greater than the thickness of the fourth electron blocking unit 1611 and the thickness of the second electron blocking unit 1412. In this way, the thickness of the fifth electron blocking unit 1612 is increased to compensate for the reduced size of the microcavity structure corresponding to the second green light emitting device due to the thinning of the thickness of the second electron blocking unit 1412, thereby improving the light extraction efficiency of the light emitted by the second green light emitting unit 1622.

[0089] In some embodiments, the ratio of the thickness of the fourth electron blocking unit 1611 to the thickness of the first electron blocking unit 1411 is a fourth ratio, and the fourth ratio is greater than or equal to 0.8 and less than or equal to 1.2. In this way, the thickness of the fourth electron blocking unit 1611 tends to be the same as the thickness of the first electron blocking unit 1411, so as to facilitate the formation of the fourth electron blocking unit 1611 and the first electron blocking unit 1411 by the same process, thereby simplifying the manufacturing process of the display panel 100.

[0090] In some embodiments, the thickness of the fourth electron blocking unit 1611 is equal to the thickness of the first electron blocking unit 1411.

[0091] In some embodiments, the thickness requirement of the fourth electron blocking unit 1611 and the first electron blocking unit 1411 is greater than and less than or equal to

[0092] In some embodiments, the material of the fourth electron blocking unit 1611 and the first electron blocking unit 1411 includes an arylamine compound. The arylamine compound is an auxiliary hole transport material, also known as an electron blocking layer material.

[0093] In some embodiments, the HOMO energy level of the fourth electron blocking unit 1611 and the first electron blocking unit 1411 is 0-0.5 eV deeper than the HOMO energy level of the first hole transport layer 144 and the second hole transport layer 163.

[0094] As shown in FIGS. 1-3, the second electron blocking layer 161 further includes a sixth electron blocking unit 1613. The second light emitting layer 162 further includes a second red light emitting unit 1623. The second red light emitting unit 1623 has a footprint on the substrate 111 that overlaps the footprint on the substrate 111 of the sixth electron blocking unit 1613 and the first red light emitting unit 1423. The second red light emitting unit 1623 is superposed with and directly contacts the sixth electron blocking unit 1613. The second red light emitting unit 1623 is superposed with the first red light emitting unit 1423.

[0095] In some embodiments, a ratio of the thickness of the sixth electron blocking unit 1613 to the thickness of the fourth electron blocking unit 1611 is a fifth ratio, and the fifth ratio is greater than the third ratio. In this way, the ratio of the thickness of the sixth electron blocking unit 1613 to the thickness of the fourth electron blocking unit 1611 is greater, and the thickness of the sixth electron blocking unit 1613 is increased to compensate for the reduced size of the microcavity structure corresponding to the second red light emitting device due to the thinning of the thickness of the third electron blocking unit 1413, thereby improving the light extraction efficiency of the light emitted by the second red light emitting unit 1623.

[0096] In some embodiments, a ratio of the fifth ratio to the third ratio is greater than or equal to 2 and less than or equal to 3. In this way, the increased value of the thickness of the sixth electron blocking unit 1613 is greater than the increased value of the thickness of the fifth electron blocking unit 1612 to better compensate for the reduced size of the microcavity structure corresponding to the second red light emitting device due to the thinning of the thickness of the third electron blocking unit 1413, thereby improving the light extraction efficiency of the light emitted by the second red light emitting unit 1623.

[0097] In some embodiments, the fifth ratio is greater than the second ratio. In this way, in the case where the thickness of the third electron blocking unit 1413 tends to be the same as the thickness of the first electron blocking unit 1411, the difference between the thickness of the sixth electron blocking unit 1613 and the thickness of the fourth electron blocking unit 1611 is greater, and the thickness of the sixth electron blocking unit 1613 is increased to compensate for the reduced size of the microcavity structure corresponding to the second red light emitting device due to the thinning of the thickness of the third electron blocking unit 1413, thereby improving the light extraction efficiency of the light emitted by the second red light emitting unit 1623.

[0098] In some embodiments, a ratio of the fifth ratio to the second ratio is greater than or equal to 10 and less than or equal to 15. In this way, the thickness of the sixth electron blocking unit 1613 is increased to compensate for the reduced size of the microcavity structure corresponding to the second red light emitting device due to the thinning of the thickness of the third electron blocking unit 1413, thereby improving the light extraction efficiency of the light emitted by the second red light emitting unit 1623.

[0099] In some embodiments, the fifth ratio is greater than or equal to 10 and less than or equal to 15. In this way, the increased thickness of the sixth electron blocking unit 1613 compensates for the reduced size of the microcavity structure corresponding to the second red light emitting device due to the thinning of the thickness of the third electron blocking unit 1413.

[0100] Optionally, the fifth ratio is greater than or equal to 10.5 and less than or equal to 14.5, greater than or equal to 11.5 and less than or equal to 13.5, or greater than or equal to 12.5 and less than or equal to 14.5.

[0101] Exemplarily, the fifth ratio is 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, or 15.

[0102] In some embodiments, the thickness of the sixth electron blocking unit 1613 is greater than the thickness of the third electron blocking unit 1413.

[0103] As shown in FIGS. 1-3, the second light-emitting stack 16 further includes a second hole transport layer 163, which is located between the charge generation layer 15 and the second electron blocking layer 161.

[0104] As shown in FIGS. 1-3, the second light-emitting stack 16 further includes an electron injection layer 166, which is located between the cathode layer 17 and the second electron transport layer 165.

[0105] In combination with the foregoing, in the case of thinning the thickness of the second electron blocking unit 1412 and the third electron blocking unit 1413 of the first electron blocking layer 141, some embodiments of the present application further increase the thickness of the fifth electron blocking unit 1612 and the sixth electron blocking unit 1613 of the second electron blocking layer 161 to compensate for the reduced thickness of the microcavity structure, improve the overall light extraction efficiency of the light emitted by the second light-emitting layer 162, and improve the display brightness of the display panel 100. Moreover, increasing the thickness of the fifth electron blocking unit 1612 and the sixth electron blocking unit 1613 of the second electron blocking layer 161 lengthens the path of electrons crossing the second electron blocking layer 161, reduces the probability of electrons entering the second hole transport layer 163 in the second light-emitting stack 16, lengthens the service life of the second hole transport layer 163, and further lengthens the service life of the display panel 100. In addition, since the hole migration rate is higher than the electron migration rate, the second electron blocking layer 161 is thickened, lengthening the path of holes entering the second light-emitting layer 162 and stabilizing the balance of charge carriers.

[0106] In some embodiments, the mass percentage of the second dopant material in the p-type charge transport layer is 1%-10% to reduce the hole migration rate and enhance the balance of charge carriers.

[0107] In some embodiments, the material of the second electron blocking unit 1412 and the fifth electron blocking unit 1612 includes but is not limited to an aromatic amine compound. The aromatic amine compound is an auxiliary hole transport material, also known as an electron blocking layer material. The HOMO energy level of the second electron blocking unit 1412 and the fifth electron blocking unit 1612 is 0-0.5 eV deeper than the HOMO energy level of the first hole transport layer 144 and the second hole transport layer 163.

[0108] In some embodiments, the material of the third electron blocking unit 1413 and the sixth electron blocking unit 1613 includes, but is not limited to, an arylamine compound. The arylamine compound is a hole auxiliary transport material, also known as an electron blocking layer material. The HOMO energy level of the third electron blocking unit 1413 and the sixth electron blocking unit 1613 is 0-0.5 eV deeper than the HOMO energy level of the first hole transport layer 144 and the second hole transport layer 163.

[0109] In some embodiments, the difference between the HOMO energy level of any one of the first electron blocking unit 1411 and the fourth electron blocking unit 1611 and the HOMO energy level of any one of the second electron blocking unit 1412 and the fifth electron blocking unit 1612 is greater than or equal to 0 eV and less than or equal to 0.1 eV. The difference between the LUMO energy level of any one of the second electron blocking unit 1412 and the fifth electron blocking unit 1612 and the LUMO energy level of any one of the first electron blocking unit 1411 and the fourth electron blocking unit 1611 is greater than or equal to 0 eV and less than or equal to 0.1 eV.

[0110] In some embodiments, the difference between the HOMO energy level of any one of the first electron blocking unit 1411 and the fourth electron blocking unit 1611 and the HOMO energy level of any one of the first hole transport layer 144 and the second hole transport layer 163 is greater than or equal to 0 eV and less than or equal to 0.1 eV.

[0111] In some embodiments, the difference between the HOMO energy level of any one of the first green light emitting unit 1422 and the second green light emitting unit 1622 and the HOMO energy level of any one of the first electron blocking unit 1411 and the fourth electron blocking unit 1611 is greater than or equal to 0.1 eV and less than or equal to 0.2 eV.

[0112] In some embodiments, the difference between the HOMO energy level of any one of the first red light emitting unit 1423 and the second red light emitting unit 1623 and the HOMO energy level of any one of the first electron blocking unit 1411 and the fourth electron blocking unit 1611 is greater than or equal to 0.1 eV and less than or equal to 0.2 eV.

[0113] The cathode layer 17 is located on the side of the second light emitting layer 162 away from the charge generation layer 15. Specifically, the cathode layer 17 is located on the side of the second light emitting stack 16 away from the substrate 111. The cathode layer 17 includes a metal material such as magnesium and silver.

[0114] As shown in FIGS. 1-3, the display panel 100 further includes a driving circuit layer 112 located between the substrate 111 and the light emitting device layer 12. The driving circuit layer 112 includes a pixel driving circuit.

[0115] As shown in FIGS. 1-3, the display panel 100 can further include a cover layer 18 located on the side of the cathode layer 17 away from the substrate 111. The refractive index of the cover layer 18 is greater than the refractive index of the cathode layer 17, so as to further improve the light extraction efficiency of the display panel 100.

[0116] The display panel 100 can further include a thin film encapsulation layer located on the side of the cover layer 18 away from the substrate 111.

[0117] As shown in FIG. 4, based on the same inventive concept, the present application further provides a display device 200 including the display panel 100 of any of the above embodiments.

[0118] The above description of the embodiments is only used to help understand the technical solutions of the present application and the core ideas thereof; it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A display panel, wherein, The display panel comprises: a substrate; and a light-emitting device layer located on one side of the substrate, and comprising: an anode layer located on one side of the substrate; a first electron blocking layer located on a side of the anode layer away from the substrate, and comprising a first electron blocking unit and a second electron blocking unit, a ratio of a thickness of the second electron blocking unit to a thickness of the first electron blocking unit is a first ratio, the first ratio is less than 2; a first light-emitting layer located on a side of the first electron blocking layer away from the anode layer, and comprising a first blue light-emitting unit and a first green light-emitting unit, a footprint of the first blue light-emitting unit on the substrate overlaps a footprint of the first electron blocking unit on the substrate, a footprint of the first green light-emitting unit on the substrate overlaps a footprint of the second electron blocking unit on the substrate; a charge generation layer located on a side of the first light-emitting layer away from the first electron blocking layer; a second light-emitting layer located on a side of the charge generation layer away from the first light-emitting layer; and a cathode layer located on a side of the second light-emitting layer away from the charge generation layer.

2. The display panel of claim 1, wherein, The first ratio is greater than or equal to 0.8 and less than or equal to 1.

2.

3. The display panel of claim 1, wherein, The first electron blocking layer further comprises a third electron blocking unit, and the first light-emitting layer further comprises a first red light-emitting unit, a footprint of the first red light-emitting unit on the substrate overlaps a footprint of the third electron blocking unit on the substrate; wherein a ratio of a thickness of the third electron blocking unit to a thickness of the first electron blocking unit is a second ratio, a ratio of the second ratio to the first ratio is greater than or equal to 0.5 and less than or equal to 6.

4. The display panel of claim 3, wherein, The second ratio is greater than or equal to 0.8 and less than or equal to 1.

2.

5. The display panel of claim 1, wherein, The display panel further comprises a second electron blocking layer located between the charge generation layer and the second light-emitting layer, and comprising a fourth electron blocking unit and a fifth electron blocking unit; The second light-emitting layer comprises a second blue light-emitting unit and a second green light-emitting unit, a footprint of the second blue light-emitting unit on the substrate overlaps footprints of the first blue light-emitting unit and the fourth electron blocking unit on the substrate, a footprint of the second green light-emitting unit on the substrate overlaps footprints of the first green light-emitting unit and the fifth electron blocking unit on the substrate; wherein a ratio of a thickness of the fifth electron blocking unit to a thickness of the fourth electron blocking unit is a third ratio, the third ratio is greater than the first ratio.

6. The display panel of claim 5, wherein, A ratio of the third ratio to the first ratio is greater than or equal to 4.5 and less than or equal to 6.

5.

7. The display panel of claim 5, wherein, A thickness of the fifth electron blocking unit is greater than a thickness of the fourth electron blocking unit and a thickness of the second electron blocking unit.

8. The display panel of claim 5, wherein, The third ratio is greater than or equal to 5 and less than or equal to 6.

9. The display panel of claim 5, wherein, A ratio of a thickness of the fourth electron blocking unit to a thickness of the first electron blocking unit is a fourth ratio, the fourth ratio is greater than or equal to 0.8 and less than or equal to 1.

2.

10. The display panel of claim 5, wherein, The first electron blocking layer further comprises a third electron blocking unit, and the first light emitting layer further comprises a first red light emitting unit, a projection of the first red light emitting unit on the substrate overlaps a projection of the third electron blocking unit on the substrate; The second electron blocking layer further comprises a sixth electron blocking unit, and the second light emitting layer further comprises a second red light emitting unit, a projection of the second light emitting unit on the substrate overlaps projections of the sixth electron blocking unit and the first red light emitting unit on the substrate; The first red light emitting unit on the substrate overlaps a projection of the third electron blocking unit on the substrate; The ratio of the thickness of the sixth electron blocking unit to the thickness of the fourth electron blocking unit is a fifth ratio, and the fifth ratio is greater than the third ratio.

11. The display panel of claim 10, wherein, The ratio of the fifth ratio to the third ratio is greater than or equal to 2 and less than or equal to 3.

12. The display panel of claim 10, wherein, The ratio of the thickness of the third electron blocking unit to the thickness of the first electron blocking unit is a second ratio, and the fifth ratio is greater than the second ratio.

13. The display panel of claim 10, wherein, The fifth ratio is greater than or equal to 10 and less than or equal to 15.

14. The display panel of claim 1, wherein, The charge generation layer comprises an n-type charge generation layer; The display panel further comprises a first hole blocking layer, the first hole blocking layer is located between the n-type charge generation layer and the first light emitting layer, and directly contacts the n-type charge generation layer.

15. The display panel of claim 1, wherein, The charge generation layer comprises an n-type charge generation layer; The display panel further comprises a first hole blocking layer and a first electron transport layer, the first hole blocking layer is located between the n-type charge generation layer and the first light emitting layer, and the first electron transport layer is located between the n-type charge generation layer and the first hole blocking layer, and directly contacts the n-type charge generation layer and the first hole blocking layer.

16. The display panel of claim 1, wherein, The charge generation layer comprises an n-type charge generation layer, and the n-type charge generation layer comprises an n-type semiconductor host material; The display panel further comprises: a first hole blocking layer located between the n-type charge generation layer and the first light emitting layer; and a first intermediate transport layer located between the first hole blocking layer and the n-type charge generation layer, directly contacts the n-type charge generation layer, and comprises the n-type semiconductor host material.

17. The display panel of claim 16, wherein, The display panel further comprises: a second hole blocking layer located between the second light emitting layer and the cathode layer; and a second electron transport layer located between the second hole blocking layer and the cathode layer; The ratio of the thickness of the first intermediate transport layer to the second electron transport layer is greater than or equal to 0.05 and less than or equal to 0.

15.

18. The display panel of claim 1, wherein, The charge generation layer further comprises an n-type charge generation layer and a p-type charge generation layer, the n-type charge generation layer is located between the p-type charge generation layer and the first light emitting layer, and the n-type charge generation layer comprises an n-type semiconductor host material; The display panel further comprises: a second intermediate transport layer located between the p-type charge generation layer and the n-type charge generation layer, and comprising the n-type semiconductor host material.

19. A display device comprising: The display device comprises a display panel, and the display panel comprises: a substrate; and a light emitting device layer located on one side of the substrate, and comprising: an anode layer located on one side of the substrate; a first electron blocking layer located on a side of the anode layer away from the substrate, and comprising a first electron blocking unit and a second electron blocking unit, a ratio of a thickness of the second electron blocking unit to a thickness of the first electron blocking unit being a first ratio, the first ratio being less than 2; a first light emitting layer located on a side of the first electron blocking layer away from the anode layer, and comprising a first blue light emitting unit and a first green light emitting unit, a footprint of the first blue light emitting unit on the substrate overlapping a footprint of the first electron blocking unit on the substrate, a footprint of the first green light emitting unit on the substrate overlapping a footprint of the second electron blocking unit on the substrate; a charge generation layer located on a side of the first light emitting layer away from the first electron blocking layer; a second light emitting layer located on a side of the charge generation layer away from the first light emitting layer; and a cathode layer located on a side of the second light emitting layer away from the charge generation layer.

20. The display device of claim 19, wherein, The first ratio is greater than or equal to 0.8 and less than or equal to 1.2.