Display panel and vapor deposition method for display panel

Abstract

The light-emitting structure layer 200 includes a first electrode 100, a second electrode 300, and a light-emitting structure layer 200 located between the first electrode 100 and the second electrode 300. The light-emitting structure layer 200 includes a light-emitting layer 240 and a plurality of doping layers 260a stacked thereon. The light-emitting structure layer 200 also includes an electron transport layer 260 located on a side of the light-emitting layer 240 away from the first electrode 100, and an electron injection layer 270 located on a side of the electron transport layer 260 away from the light-emitting layer 240. Here, the electron transport layer 260 is an electron transport layer. The display panel 10 and the vapor deposition method for the display panel 10 have a reference plane Q' located at the center of the display panel 10 in the thickness direction, and the energy level of each doping layer 260a located on the side of the reference plane Q' facing the light-emitting layer 240 is directly proportional to the distance from the doping layer 260a to the light-emitting layer 240, and the energy level of each doping layer 260a located on the side of the reference plane Q' facing the electron injection layer 270 is directly proportional to the distance from the doping layer 260a to the electron injection layer 270.

Description

[Technical field]

[0001] This application claims priority to Chinese Patent Application No. 202011404561.X, entitled "Display Panel and Deposition Method for Display Panel," filed on December 4, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the field of display technology, in particular to a display panel and a deposition method for the display panel. [Background technology]

[0003] Organic Light-Emitting Diode (OLED) is an active light-emitting device. Compared with the conventional Liquid Crystal Display (LCD) display method, OLED display technology does not require a backlight and has the characteristic of self-emitting light. OLED adopts a thin organic material film layer and a glass substrate, and the organic material emits light when an electric current flows. Therefore, OLED display panels can significantly save electric energy, can be lighter and thinner, can withstand a wider range of temperature changes than LCD display panels, and has a wider viewing angle. OLED display panels have the potential to become the next-generation flat panel display technology following LCD, and are one of the most noteworthy technologies in the current flat panel display technology.

[0004] Power consumption is an important indicator of an OLED display panel, and power consumption is equal to the product of voltage and current. For an OLED display panel, reducing the voltage at a certain brightness of the OLED can effectively reduce the power consumption of the panel. Doping an electron transport material layer is a common method to reduce the voltage. For current mass-produced devices, the doping ratio of the dopant and the doping body is constant with the change of film thickness, and this method cannot reduce the voltage to the minimum. Summary of the Invention

[0005] The embodiments of the present application provide a display panel and a deposition method for the display panel, which aims to reduce the power consumption of the display panel.

[0006] An embodiment according to a first aspect of the present application provides a display panel including a first electrode, a second electrode, and a light-emitting structure layer located between the first electrode and the second electrode, the light-emitting structure layer including a light-emitting layer, an electron transport layer provided on a side of the light-emitting layer away from the first electrode, and an electron injection layer located on a side of the electron transport layer away from the light-emitting layer, the electron transport layer including a plurality of doped layers provided in a stacked manner, the electron transport layer having a reference plane located at a center portion of the electron transport layer in a thickness direction of the display panel, an energy level of each doped layer located on the side of the reference plane facing the light-emitting layer being directly proportional to the distance from the doped layer to the light-emitting layer, and an energy level of each doped layer located on the side of the reference plane facing the electron injection layer being directly proportional to the distance from the doped layer to the electron injection layer.

[0007] An embodiment according to a second aspect of the present application is a deposition method for a display panel, comprising: placing a substrate to be deposited on a placement stage; placing a first material in a first deposition cabin and a second material in a second deposition cabin; the first deposition cabin and the second deposition cabin are distributed along a second direction; the first deposition cabin, the second deposition cabin and the placement stage are distributed at intervals along the first direction; a first opening of the first deposition cabin and a second opening of the second deposition cabin are both directed toward the substrate to be deposited; and an energy level of the first material is greater than an energy level of the second material; The deposition method includes driving a first deposition cabin and a second deposition cabin to move from a first position to a second position along a second direction, the deposition substrate having a predetermined center in the second direction, the predetermined center extending along the first direction to form an imaginary line perpendicular to the deposition substrate, a first included angle being formed between a connecting line between the first opening and the predetermined center and the imaginary line, and a second included angle being formed between a connecting line between the second opening and the predetermined center and the vertical direction, the first included angle being larger than the second included angle at the first position, and the first included angle being smaller than the second included angle at the second position.

[0008] An embodiment according to a third aspect of the present application is a deposition method for a display panel, comprising: placing a substrate to be deposited on a placement stage; placing a first material in a first deposition cabin and a second material in a second deposition cabin; the first deposition cabin, the second deposition cabin and the placement stage are distributed at intervals along a first direction; a first opening of the first deposition cabin and a second opening of the second deposition cabin are both directed toward the substrate to be deposited; an energy level of the first material is higher than an energy level of the second material; and moving the first deposition cabin and the second deposition cabin from a third position along the second direction. and driving the first deposition cabin to move the second deposition cabin to position 4; and a first deposition rate in the first deposition cabin is different from a second deposition rate in the second deposition cabin, so that a first doping layer and a second doping layer are sequentially deposited on the deposition substrate, wherein a doping rate of the first material in the first doping layer is smaller than a doping rate of the second material, a doping rate of the first material in the second doping layer is larger than a doping rate of the second material, and an energy level of the first doping layer is smaller than an energy level of the second doping layer.

[0009] In the display panel of the embodiment of the present application, the display panel includes a first electrode, a second electrode, and a light-emitting structure layer located between the first electrode and the second electrode, and the light-emitting structure layer can emit light by the action of the first electrode and the second electrode. The light-emitting structure layer includes a light-emitting layer, an electron transport layer, and an electron injection layer, and the electron transport layer includes a plurality of doping layers. In the direction of the electron transport layer toward the light-emitting layer, the energy level of the doping layer is directly proportional to the distance from itself to the light-emitting layer, i.e., the closer to the light-emitting layer, the lower the energy level of the doping layer, so that the injection barrier of electrons from the electron transport layer to the light-emitting layer can be reduced, the voltage rise due to electron transport can be reduced, and the voltage required for the light emission of the display panel can be reduced. In the direction of the electron transport layer toward the electron injection layer, the energy level of the doping layer is directly proportional to the distance from itself to the electron injection layer, i.e., the closer to the electron injection layer, the lower the energy level of the doping layer, so that the injection barrier of electrons from the electron injection layer to the electron transport layer can be reduced, the voltage rise due to electron transport can be reduced, and the voltage required for the light emission of the display panel can be reduced. Therefore, the present invention can reduce the power consumption of the display panel. [Brief description of the drawings]

[0010] [Figure 1] 1 is a partial cross-sectional view of a display panel provided by an embodiment of a first aspect of the present application. [Diagram 2] FIG. 2 is a structural schematic diagram of an electron transport layer of a display panel provided by an embodiment of the first aspect of the present application. [Diagram 3] FIG. 2 is a structural schematic diagram of an electron transport layer of a display panel provided by another embodiment of the first aspect of the present application. [Figure 4] 4 is a current density-voltage graph of the display panel measured in Example 1. [Diagram 5] 4 is a luminance decay graph of a display panel measured according to Example 1. [Figure 6] 11 is a graph showing current density-voltage of a display panel measured in Comparative Example 1. [Figure 7] 1 is a graph showing luminance attenuation of a display panel measured in Comparative Example 1. [Figure 8] 4 is a flow chart of a deposition method for a display panel provided by an embodiment of a second aspect of the present application. [Figure 9] FIG. 2 is a schematic diagram of a vapor deposition apparatus in use when vapor deposition is performed using a vapor deposition method according to an embodiment of a second aspect of the present application. [Figure 10] 4 is a flow chart of a deposition method for a display panel provided by another embodiment of the second aspect of the present application. [Figure 11] 4 is a flow chart of a deposition method for a display panel provided by an embodiment of a third aspect of the present application. [Figure 12] 4 is a graph of the doping ratio of a first material to a second material at different thicknesses on a deposited substrate as measured by deposition rate. [Figure 13] 4 is a graph of the doping ratio of a first material to a second material at different thickness positions on a deposited substrate measured at different deposition rates. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In order to better understand the present application, a display panel and a deposition method for the display panel according to an embodiment of the present application will be described in detail below with reference to FIGS.

[0012] 1 , a display panel 10 provided by an embodiment of the first aspect of the present application includes a first electrode 100, a second electrode 300, and a light-emitting structure layer 200 located between the first electrode 100 and the second electrode 300. The light-emitting structure layer 200 includes a light-emitting layer 240, an electron transport layer 260 disposed on a side of the light-emitting layer 240 away from the first electrode 100, and an electron injection layer 270 disposed on a side of the electron transport layer 260 away from the light-emitting layer 240. The electron transport layer 260 includes a plurality of doped layers 260a arranged in a stacked manner, and the electron transport layer 260 has a reference plane Q' that is located at the center of the electron transport layer 260 in the thickness direction of the display panel 10 (Z direction in Figure 1), and the energy level of each doped layer 260a located on the side of the reference plane Q' facing the light-emitting layer 240 is directly proportional to the distance from itself to the light-emitting layer 240, and the energy level of each doped layer 260a located on the side of the reference plane Q' facing the electron injection layer 270 is directly proportional to the distance from itself to the electron injection layer 270.

[0013] 1, the position of the reference plane Q' is indicated by a dashed line, and the dashed line does not limit the structure of the display panel 10 provided by the embodiment of the first aspect of the present application. The reference plane Q' is also not a specific structure of the electron transport layer 260, and in order to more clearly express the characteristic points of the present application, the doping layer 260 at different positions based on the reference plane Q' is also shown. a Explain the energy levels of

[0014] The energy levels referred to herein are Lowest Unoccupied Molecular Orbital (LUMO) energy levels.

[0015] In the display panel 10 according to the embodiment of the present application, the light emitting structure layer 200 can emit light through the action of the first electrode 100 and the second electrode 300. The electron transport layer 260 includes N doping layers 260a.

[0016] In the present application, in the direction of the electron transport layer 260 toward the light-emitting layer 240, the energy level of the doped layer 260a is directly proportional to the distance from the doped layer 260a to the light-emitting layer 240, i.e., the closer the doped layer 260a is to the light-emitting layer 240, the lower the energy level of the doped layer 260a is. This reduces the barrier for electron injection from the electron transport layer 260 to the light-emitting layer 240, reduces the voltage increase due to electron transport, and further reduces the voltage required for light emission of the display panel 10.

[0017] In the direction of the electron transport layer 260 toward the electron injection layer 270, the energy level of the doped layer 260a is directly proportional to the distance from the doped layer 260a to the electron injection layer 270; that is, the closer the doped layer 260a is to the electron injection layer 270, the lower the energy level of the doped layer 260a. This reduces the barrier for electron injection from the electron injection layer 270 to the electron transport layer 260, reduces the voltage increase due to electron transport, and further reduces the voltage required for light emission of the display panel 10.

[0018] As a result, the display panel 10 according to the embodiment of the present application can reduce the voltage required to reach the target luminance, and further reduce the power consumption of the display panel 10.

[0019] The light emitting structure layer 200 may be provided in various configurations, and optionally may further include a hole blocking layer 250 provided between the electron transport layer 260 and the light emitting layer 240, and a hole injection layer 210, a hole transport layer 220, and an electron blocking layer 230 stacked on one side in the direction from the first electrode 100 to the light emitting layer 240. The display panel 10 may further include, for example, a light extraction layer 400 and a sealing layer 500 provided on the side of the second electrode 300 away from the light emitting structure layer 200.

[0020] Although the number of the doping layers 260a is not limited, the embodiment of the first aspect of the present application will be described taking an example in which the number of the doping layers 260a is three.

[0021] 2, the plurality of doping layers 260a provided in a stacked manner includes a first doping layer 261, a second doping layer 262 located on a side of the first doping layer 261 away from the light emitting layer 240, and a third doping layer 263 located on a side of the second doping layer 262 away from the first doping layer 261, and the energy level of the second doping layer 262 is higher than the energy levels of the first doping layer 261 and the third doping layer 263. Optionally, the second doping layer 262 electronic The reference plane Q′ may be located at the second doped layer 262 if located close to the center of the thickness of the transport layer 260 .

[0022] In these optional embodiments, the energy level of the first doping layer 261 is lower than that of the second doping layer 262, so that the barrier for electron injection from the electron transport layer 260 to the light emitting layer 240 can be reduced and the voltage rise due to electron transport can be reduced. The energy level of the third doping layer 263 is lower than that of the second doping layer 262, so that the barrier for electron injection from the electron injection layer 270 to the electron transport layer 260 can be reduced and the voltage rise due to electron transport can be reduced.

[0023] The energy levels at different thickness positions in the first doped layer 261 may be the same or different, for example, in the direction from the reference plane Q' to the light emitting layer 240, the energy level of the first doped layer 261 gradually decreases, thereby further reducing the electron injection barrier.

[0024] In the third doped layer 263, the energy levels at different thickness positions may be the same or different, for example, the energy level of the third doped layer 263 gradually decreases in the direction from the reference plane Q' to the electron injection layer 270, thereby further reducing the electron injection barrier.

[0025] In the second doped layer 262, the energy levels at different thickness positions may be the same or different. For example, with the reference plane Q' as the limit, the energy level of the second doped layer 262 gradually decreases in the direction from the reference plane Q' to the light-emitting layer 240, and the energy level of the second doped layer 262 gradually decreases in the direction from the reference plane Q' to the electron injection layer 270, thereby further reducing the electron injection barrier.

[0026] Optionally, throughout the electron transport layer 260, the energy levels of the electron transport layer 260 gradually decrease from the reference plane Q′ to the light-emitting layer 240, and the energy levels of the electron transport layer 260 gradually decrease from the reference plane Q′ to the electron injection layer 270.

[0027] As shown in FIG. 3, the doped layer 260a further includes, for example, a fourth doped layer 264 located on the side of the first doped layer 261 away from the second doped layer 262, and the energy level of the fourth doped layer 264 is lower than the energy level of the first doped layer 261, thereby further reducing the injection barrier of electrons from the electron transport layer 260 to the light emitting layer 240.

[0028] The doped layer 260a further includes, for example, a fifth doped layer 265 located on the side of the third doped layer 263 away from the second doped layer 262, and the energy level of the fifth doped layer 265 is lower than the energy level of the third doped layer 263, thereby further reducing the injection barrier of electrons from the electron injection layer 270 to the electron transport layer 260.

[0029] Optionally, the energy level of the doped layer 260a can be reduced in multiple ways, for example, by doping the low energy level doped layer 260a with a material having a lower energy level, or by doping the high energy level doped layer 260a with a material having a higher energy level, to increase the energy level of the doped layer 260a.

[0030] In some alternative embodiments, the materials of the first doped layer 261 and the third doped layer 263 include at least a second material, and the second doped layer 262 is formed by doping the second material and the first material, and the energy level of the first material is higher than the energy level of the second material.

[0031] In these optional embodiments, the energy level of the second doped layer 262 can be raised by doping the second doped layer 262 with a first material having a higher energy level, making the energy level of the first doped layer 261 lower than the energy level of the second doped layer 262.

[0032] In some embodiments, the electron mobility of the first material is greater than that of the second material, so that doping the second doped layer 262 with the first material can improve the electron mobility of the second doped layer 262, improve the electron mobility of the entire film layer, and improve the light emitting efficiency.

[0033] The electron mobility of the first material is, for example, 9×10 -4 cm 2 / Vs~1×10 -5 cm 2 / Vs. The electron mobility of the second material is 9×10 -6 cm 2 / Vs~1×10 -7 cm 2 / Vs.

[0034] The LUMO energy level of the first material is −1.0 eV to −3.0 eV, and the LUMO energy level of the second material is 3 eV or less.

[0035] The first material includes at least one of TmPyPb and 3TPYMPB, and the second material includes 8-quinolinolatrinium, and the like.

[0036] In some embodiments, the electron mobility of the first doped layer 261 and the third doped layer 263 can be further improved by doping the first doped layer 261 and the third doped layer 263 with a first material.

[0037] Optionally, the materials of the first doped layer 261 and the third doped layer 263 include a second material and a first material, the doping percentage of the second material in the first doped layer 261 is greater than the doping percentage of the first material, the doping percentage of the first material in the second doped layer 262 is greater than the doping percentage of the second material, and the doping percentage of the second material in the third doped layer 263 is greater than the doping percentage of the first material.

[0038] In these alternative embodiments, the doping rate of the second material in the first doping layer 261 is greater than the doping rate of the first material, and the doping rate of the first material in the second doping layer 262 is greater than the doping rate of the second material, and the energy level of the first doping layer 261 is reduced to a level lower than the energy level of the second doping layer 262, under the premise of improving the electron mobility of the first doping layer 261. The doping rate of the second material in the third doping layer 263 is greater than the doping rate of the first material, and the energy level of the third doping layer 263 is reduced to a level lower than the energy level of the second doping layer 262, under the premise of improving the electron mobility of the third doping layer 263.

[0039] Optionally, the doping ratio of the first material in the first doping layer 261 is smaller than the doping ratio of the first material in the second doping layer 262, so that the energy level of the first doping layer 261 can be further reduced and the electron mobility of the second doping layer 262 can be improved.

[0040] Optionally, the doping ratio of the first material in the third doped layer 263 is smaller than the doping ratio of the first material in the second doped layer 262, so that the energy level of the third doped layer 263 can be further reduced and the electron mobility of the second doped layer 262 can be improved.

[0041] Optionally, the doping ratio of the first material to the second material in the first doping layer 261 is less than 1, and optionally, the doping ratio of the first material to the second material in the first doping layer 261 is 1:9 to 3.5:6.5. For example, the doping ratio of the first material to the second material in the first doping layer 261 is 1:9, 2:8, 3:7, 4:6, or 3.5:6.5, etc.

[0042] Optionally, the doping ratio of the first material to the second material in the second doped layer 262 is greater than 1. Optionally, the doping ratio of the first material to the second material in the second doped layer 262 is 6.5:3.5 to 9:1. For example, the doping ratio of the first material to the second material in the second doped layer 262 is 9:1, 8:2, 7:3, 6:4, or 6.5:3.5.

[0043] Optionally, the doping ratio of the first material to the second material in the third doping layer 263 is less than 1. Optionally, the doping ratio of the first material to the second material in the first doping layer 261 is 1:9 to 3.5:6.5. For example, the doping ratio of the first material to the second material in the third doping layer 263 is 2:8, 3:7, 4:6, or 3.5:6.5, etc.

[0044] The doping ratios of the first material and the second material in the first doping layer 261 and the third doping layer 263 may be the same or different. Optionally, the doping ratios of the first material and the second material in the first doping layer 261 and the third doping layer 263 are the same, and the first doping layer 261 and the third doping layer 263 can be fabricated using the same process parameters and process steps, which can reduce the difficulty of the manufacturing process of the display panel 10 and improve the manufacturing efficiency of the display panel 10.

[0045] The second doped layer 262 has a thickness of 18 nm to 30 nm.

[0046] Optionally, the first doped layer 261 has a thickness of 1 nm-5 nm.

[0047] Optionally, the thickness of the third doped layer 263 is 1 nm-5 nm.

[0048] Example 1 In order to verify this technical solution, the following solution is designed: the doping layer 260a includes a first doping layer 261, a second doping layer 262 and a third doping layer 263, and the first doping layer 261, the second doping layer 262 and the third doping layer 263 are all formed by doping a first material and a second material. The ratio of the first material to the second material in the first doping layer 261 and the third doping layer 263 is kept at 4:6, the thickness of the first doping layer 261 and the third doping layer 263 is 20A, and the thickness of the second doping layer 262 is 240A. The ratio of the first material to the second material in the second doping layer 262 is changed between 10:2 and 2:8, and the power where the ratio of the first material to the second material in the second doping layer 262 is 4:6 is compared as the base power, and the data for obtaining parameters such as each current, voltage, and brightness where the light emission brightness of the display panel 10 is 733 nit is as follows:

[0049] [Table 1]

[0050] where ET1:ET2 is the ratio of the first material to the second material, voltage is the voltage required to reach the target luminance, current is the current at which the target luminance is reached, CIE-x and CIE-y are the color coordinates of the color of the emitting subpixel, BI is the Blue Light Index, P is the power consumption at which the target luminance is reached, and ±P is the comparison of the power consumption produced when the ratio of the first material to the second material is 4:6.

[0051] From the above data table we can see the following: 1) When the ratio of the first material to the second material in the second doping layer 262 is reduced to 2:8, the light emitting voltage of the display panel 10 increases sharply and does not reach the target brightness. 2) With the increase of the ratio of the first material in the second doping layer 262, the voltage of the display panel 10 is reduced to some extent, where when the ratio of the first material to the second material is 7:3 and 5:5, the voltage is reduced at most by about 0.4V, but the reduction in efficiency is not obvious. When the ratio of the first material to the second material in the second doping layer 262 is 10:0, the voltage of the display panel 10 is increased to 6.78V, and the efficiency is significantly reduced to 0.00824W. 3) As can be seen from calculating the power consumption of the display panel 10 by the product of voltage and current, when the ratio of the first material to the second material in the second doping layer 262 is between 5:5 and 8:2, the power consumption is reduced in all cases, and when the ratio of the first material to the second material in the second doping layer 262 is 7:3, the reduction in power consumption is most significant, and the power consumption is reduced by 5.5%.

[0052] 4, when the ratio of the first material to the second material in the second doping layer 262 is between 5:5 and 9:1, the current density is obviously higher than that when the ratio of the first material to the second material in the second doping layer 262 is 4:6. When the ratio of the first material to the second material in the second doping layer 262 is 10:0 and 2:8, the current density decreases rapidly, which causes the voltage to increase rapidly and even the target brightness cannot be reached.

[0053] As shown in FIG. 5, based on the luminance decay graph measured on the display panel 10 of Example 1, the initial luminance is 733 nits.

[0054] 5, the luminance decay when the ratio of the first material to the second material in the second doping layer 262 is 7:3 is almost the same as that when the ratio of the first material to the second material in the second doping layer 262 is 4:6. That is, when the ratio of the first material to the second material in the second doping layer 262 is adjusted from 4:6 to 7:3, the impact on the service life of the second doping layer 262 is very limited. When the ratio of the first material to the second material in the second doping layer 262 is other ratios, the decay rate of the second doping layer 262 increases, that is, the service life of the second doping layer 262 decreases.

[0055] Comparative Example 1 A comparative test was conducted in which the ratio of the first material to the second material in the second doping layer 262 was 7:3, and the doping ratios in the first doping layer 261 and the third doping layer 263 were different, and the results were as follows:

[0056] [Table 2]

[0057] Here, the first set of data shows detection results obtained when the doping ratio between the first material and the second material in the first doping layer 261, the second doping layer 262, and the third doping layer 263 is all 7:3. The second set of data shows detection results obtained when the doping ratio between the first material and the second material in the first doping layer 261 and the third doping layer 263 is all 2:8, and the doping ratio between the first material and the second material in the second doping layer 262 is 7:3.

[0058] As can be seen from the above data table, the power consumption of the display panel 10 is low when the doping ratio between the first material and the second material in both the first doped layer 261 and the third doped layer 263 is 2:8.

[0059] As can be seen from FIG. 6, when the doping ratio between the first material and the second material in the first doping layer 261 and the second doping layer 262 is 2:8, it is estimated that the current density increases, the voltage of the display panel 10 at the target luminance is reduced by 0.12 V, and the power consumption of the display panel 10 is reduced by 4.3%.

[0060] Referring to FIG. 7, FIG. 7 is a schematic diagram of luminance decay measured in the display panel 10 according to Comparative Example 1. The initial luminance is 1200nits It is.

[0061] As can be seen from the luminance decay graph, when the doping ratio of the first material to the second material in the first doping layer 261 and the second doping layer 262 is 2:8, the device service life of the display panel 10 can be improved to a certain extent. The deposition method for the display panel 10 provided in the second aspect of the present application includes:

[0062] Step S01: Deposition substrate 23 is placed on the mounting table.

[0063] Step S02: A first material is placed in the first deposition cabin 21, and a second material is placed in the second deposition cabin 22.

[0064] Here, the first deposition cabin 21 and the second deposition cabin 22 are distributed along the second direction (X direction in FIG. 9 ), and the first deposition cabin 21, the second deposition cabin 22 and the mounting table are distributed at intervals along the first direction (Y direction in FIG. 9 ). A first opening 21a of the first deposition cabin 21 and a second opening 22a of the second deposition cabin 22 are both arranged to face the substrate to be deposited. 23 , where the energy level of the first material is greater than the energy level of the second material.

[0065] Step S03: The first deposition cabin 21 and the second deposition cabin 22 are driven to move from the first position to the second position along the second direction.

[0066] Deposition substrate 23 has a predetermined center in the second direction, and the predetermined center extends along the first direction to the substrate to be deposited. 23 9, a connecting line between the first opening 21a and the predetermined center and the virtual line form a first included angle O1, and a connecting line between the second opening 22a and the predetermined center and the vertical direction form a second included angle O2, in the first position, the first included angle O1 is larger than the second included angle O2, and in the second position, the first included angle O1 is smaller than the second included angle O2. In FIG. 9, a solid line shows a usage state diagram when the first deposition cabin 21 and the second deposition cabin 22 are in the first position, and a dashed line shows a usage state diagram when the first deposition cabin 21 and the second deposition cabin 22 are in the second position.

[0067] In the deposition method for the display panel 10 according to the second embodiment of the present invention, first, a substrate to be deposited is 23 Next, the first material is placed in the first deposition cabin 21 and the second deposition cabin 22, and the first opening 21a and the second opening 22a are both open to the substrate to be deposited. 23 The first material is directed toward the deposition substrate through the first opening 21a. 23 The second material can be deposited on the substrate through the second opening 22a. 23Finally, the first deposition cabin 21 and the second deposition cabin 22 are driven to move from the first position to the second position.

[0068] In the first position, the first included angle O1 is greater than the second included angle O2, i.e., the first opening 21a and the deposition substrate 23 The distance between the second opening 22a and the deposition substrate is 23 Therefore, when deposition is started at the first position, the distance between the deposition target substrate is larger than the distance between the deposition target substrate and the deposition target substrate. 23 The deposition amount of the second material is greater than the deposition amount of the first material.

[0069] In the second position, the first included angle O1 is smaller than the second included angle O2, i.e., the first opening 21a and the deposition substrate 23 The distance between the second opening 22a and the deposition substrate is 23 When the deposition head is in the second position, the distance between the deposition head and the substrate is smaller than the distance between the deposition head and the substrate. 23 The deposition amount of the first material is greater than the deposition amount of the second material.

[0070] Therefore, the substrate on which the display panel 10 is deposited by the deposition method of the present invention 23 can form layer structures with the same doping material in the deposition process, but different doping ratios of the materials.

[0071] For example, in the process of depositing the electron transport layer 260 of the display panel 10 according to the embodiment of the first aspect of the present application using the deposition method according to the embodiment of the second aspect of the present application, different doped layers 260a can be formed, and the doping ratios of the first material and the second material in the different doped layers 260a are different.

[0072] In some alternative embodiments, after step S03, the method further includes step S04 of driving the first deposition cabin 21 and the second deposition cabin 22 to move from the second position to the first position. In these embodiments, layer structures having the same doping material but different doping ratios of the materials can be formed by successive deposition.

[0073] Optionally, the first position and the second position are distributed symmetrically with respect to a predetermined center, so that the deposition amount and material ratio of the first material and the second material deposited by moving from the first position to the second position are the same as the deposition amount and material ratio of the first material and the second material deposited by moving from the second position to the first position.

[0074] Referring to FIG. 10, the following describes a deposition method for the display panel 10 provided in the embodiment of the second aspect of the present application, taking as an example the deposition of the display panel 10 provided in FIG. 1 and FIG. 2.

[0075] Step S01': A first electrode 100 is formed on a substrate by deposition.

[0076] Step S02': The light emitting layer 240 of the light emitting structure layer 200 is formed on the first electrode 100 by deposition. Optionally, before step S02', layer structures such as the hole injection layer 210, the hole transport layer 220, and the electron blocking layer 230 in the light emitting structure layer 200 can be formed by deposition on the first electrode 100. After step S02', layer structures such as the hole blocking layer 250 can be formed on the light emitting layer 240 by deposition.

[0077] Step S03′: A first material is placed in the first deposition cabin 21, and a second material is placed in the second deposition cabin 22.

[0078] Step S04': The first deposition cabin 21 and the second deposition cabin 22 are moved from the first position to the second position.

[0079] In the process of moving the first deposition cabin 21 and the second deposition cabin 22 from the first position to the second position, at the start stage, the first included angle O1 is greater than the second included angle O2, the deposition amount of the first material is smaller than the deposition amount of the second material, and the first doping layer 261 can be formed. When the first included angle O1 and the second included angle O2 are equal, the deposition of the first doping layer 261 is finished. When the first included angle O1 is smaller than the second included angle O2, the deposition of the second doping layer 262 begins.

[0080] Step S05': The first deposition cabin 21 and the second deposition cabin 22 are moved from the second position to the first position.

[0081] In the process of moving the first deposition cabin 21 and the second deposition cabin 22 from the second position to the first position, at the beginning stage, the first included angle O1 is smaller than the second included angle O2, the deposition amount of the first material is larger than the deposition amount of the second material, and the second doping layer 262 can be continuously formed. When the first included angle O1 and the second included angle O2 are equal, the deposition of the second doping layer 262 is completed. When the first included angle O1 is larger than the second included angle O2, the deposition of the third doping layer 263 begins. Finally, when the first deposition cabin 21 and the second deposition cabin 22 are moved to the first position, the deposition of the third doping layer 263 is completed.

[0082] Step S06′: The electron injection layer 270 is formed in the third doping layer 263.

[0083] When the deposition method provided in the embodiment of the second aspect of the present application is used to deposit the electron transport layer 260 in steps S03' to S05', the first doping layer 261, the second doping layer 262 and the third doping layer 263 can be deposited, and the doping ratio of the first material in the first doping layer 261 is smaller than the doping ratio of the second material, so that the energy level of the first doping layer 261 is low, and the doping ratio of the first material in the second doping layer 262 is larger than the doping ratio of the second material, so that the electron mobility of the second doping layer 262 is high, and the energy level of the first doping layer 261 is smaller than the energy level of the second doping layer 262. Similarly, the energy level of the third doping layer 263 is smaller than the energy level of the second doping layer 262.

[0084] In addition, when the electron transport layer 260 is formed by the deposition method provided in the embodiment of the second aspect of the present application, the energy level of the electron transport layer 260 gradually decreases in the direction from the reference plane Q' to the light-emitting layer 240, with the reference plane Q' being the limit in the thickness direction of the electron transport layer 260, in the direction toward the light-emitting layer 240 of the reference plane Q', and the energy level of the electron transport layer 260 gradually decreases in the direction from the reference plane Q' to the electron injection layer 270, thereby further reducing the electron injection barrier and reducing the power consumption of the display panel 10.

[0085] Referring to FIG. 11, a third aspect of the present application further provides a deposition method for a display panel, including:

[0086] Step S1: Substrate to be deposited 23 is placed on the mounting table.

[0087] Step S2: A first material is placed in the first deposition cabin 21, and a second material is placed in the second deposition cabin 22.

[0088] The first deposition cabin 21, the second deposition cabin 22, and the mounting table are arranged at intervals along a first direction (Y direction in FIG. 9 ). A first opening 21 a of the first deposition cabin 21 and a second opening 22 a of the second deposition cabin 22 are arranged to face the substrate to be deposited. 23 , and the energy level of the first material is greater than the energy level of the second material.

[0089] In the deposition method provided by the embodiment of the present application, the first deposition cabin 21 and the second deposition cabin 22 may be distributed along the second direction (X direction in FIG. 9 ) as shown in FIG. 9 . Alternatively, the first deposition cabin 21 and the second deposition cabin 22 may be arranged side by side. There is no limitation on the initial installation positions of the first deposition cabin 21 and the second deposition cabin 22.

[0090] Step S3: The first deposition cabin 21 and the second deposition cabin 22 are driven to move from the third position to a fourth position along the second direction, and the first deposition rate of the first deposition cabin 21 and the second deposition rate of the second deposition cabin 22 are different.

[0091] The first deposition rate of the first deposition cabin 21 refers to the amount of the first material deposited from the first opening 21a during the movement of the first deposition cabin 21, or the first deposition rate of the first deposition cabin 21 refers to the amount of the first material deposited on the deposition substrate 23 during the movement of the first deposition cabin 21.

[0092] Similarly, the second deposition rate of the second deposition cabin 22 is the second deposition rate during the movement of the second deposition cabin 22. 2 The second deposition rate of the second deposition cabin 22 refers to the amount of the second material deposited on the deposition substrate 23 during the movement of the second deposition cabin 22, or the second deposition rate of the second deposition cabin 22 refers to the amount of the second material deposited on the deposition substrate 23 during the movement of the second deposition cabin 22.

[0093] A first deposition rate in the first deposition cabin 21 and a second deposition rate in the second deposition cabin 22 are different from each other, and the deposition amounts of the first material and the second material are different from each other on the deposition substrate 23. A first doped layer 261 and a half of a second doped layer 262 adjacent to the first doped layer 261 are sequentially formed by deposition on the deposition substrate 23, and the doping ratio of the first material in the first doped layer 261 is smaller than that of the second material, the doping ratio of the first material in the second doped layer 262 is larger than that of the second material, and the energy level of the first doped layer 261 is smaller than that of the second doped layer 262.

[0094] In the third position, the first deposition cabin 21 and the second deposition cabin 22 may be arranged in a number of relative positions, for example, the first deposition cabin 21 and the second deposition cabin 22 may be arranged according to the first position, and O1 may be greater than O2. In another embodiment, the first deposition cabin 21 and the second deposition cabin 22 may be arranged in parallel, i.e., O1 is equal to O2. Alternatively, the first deposition cabin 21 and the second deposition cabin 22 may be arranged in the opposite manner to the first position, i.e., O1 is smaller than O2. In the fourth position, the sizes of O1 and O2 are not limited, and O1 may be greater than O2, or O1 may be equal to O2, or O1 may be smaller than O2. It is only necessary that the first doping layer 261 and half of the second doping layer 262 can be deposited.

[0095] In another embodiment, after step S3, the method further includes step S4 of driving the first deposition cabin 21 and the second deposition cabin 22 to move from the fourth position to the third position. The other half of the second doping layer 262 and the third doping layer 263 are formed.

[0096] In the deposition method for the display panel 10 provided by the embodiment of the third aspect of the present application, the deposition rates of the first deposition cabin 21 and the second deposition cabin 22 are reasonably adjusted to form two doping layers 260 having different energy levels. acan be formed.

[0097] In some alternative embodiments, the above-mentioned third embodiment and the second embodiment can be combined. For example, in the deposition method provided by the second embodiment of the present application, the deposition rates of the first deposition cabin 21 and the second deposition cabin 22 can be reasonably adjusted to deposit doping layers 260a with different ratios. The deposition rates of the first deposition cabin 21 and the second deposition cabin 22 can be the same or different, and the deposition rates of the first deposition cabin 21 and the second deposition cabin 22 can be controlled independently of each other.

[0098] In the following, the deposition speed ratios between the first deposition cabin 21 and the second deposition cabin 22 are 7:3 and 4:6, respectively, and deposition is performed by moving the first deposition cabin 21 and the second deposition cabin 22 from the first position to the second position and then from the second position to the first position.

[0099] 12 and 13, FIG. 12 shows the measured deposition rate of a substrate when the deposition rate ratio between the first deposition cabin 21 and the second deposition cabin 22 is 7:3. 23 13 shows a graph of the doping ratio of the first material and the second material at different thickness positions in the case where the deposition rate ratio of the first deposition cabin 21 to the second deposition cabin 22 is 4:6. 23 1 shows a graph of the doping ratio of a first material and a second material at different thickness positions in a semiconductor device according to the present invention.

[0100] In Fig. 12 and Fig. 13, the horizontal axis indicates different thickness positions. Assuming that the first doping layer 261 and the third doping layer 263 have a thickness of 20A, and the second doping layer 262 has a thickness of 240A, the thickness value of 0A to 20A is the first doping layer 261, the thickness value of 21A to 260A is the second doping layer 262, and the thickness value of 261A to 280A is the third doping layer 263. The following can be seen from Fig. 12 and Fig. 13.

[0101] 1) When the first deposition cabin 21 and the second deposition cabin 22 deposit with a deposition rate ratio of 7:3, the doping ratio of the first material to the second material in the first doping layer 261 and the third doping layer 263 is about 5:5, and the doping ratio of the first material to the second material in the second doping layer 262 is about 9:1.

[0102] 2) When the first deposition cabin 21 and the second deposition cabin 22 deposit with a deposition rate ratio of 4:6, the doping ratio of the first material to the second material in the first doping layer 261 and the third doping layer 263 is about 2:8, and the doping ratio of the first material to the second material in the second doping layer 262 is about 6.5:3.5.

[0103] Therefore, it can be seen that the doping ratio between the first material and the second material can be adjusted by changing the deposition rates in the first deposition cabin 21 and the second deposition cabin 22.

[0104] In other embodiments, the doping ratio of the first material to the second material can be changed by further changing the spacing between the first deposition cabin 21 and the second deposition cabin 22 at the first position and / or the second position.

Claims

1. A display panel including a first electrode, a second electrode, and a light-emitting structure layer located between the first electrode and the second electrode, The light emitting structure layer is A light-emitting layer; an electron transport layer provided on a side of the light emitting layer away from the first electrode; an electron injection layer located on a side of the electron transport layer away from the light emitting layer; The electron transport layer includes a plurality of doping layers stacked one on top of the other; and the electron transport layer has a reference surface located at a center of the electron transport layer in a thickness direction of the display panel, the LUMO energy level of each of the doped layers located on the side of the reference plane facing the light-emitting layer is directly proportional to the distance from itself to the light-emitting layer; the LUMO energy level of each of the doped layers on the side of the reference plane facing the electron injection layer is directly proportional to the distance from the doped layer to the electron injection layer; the plurality of doped layers provided in a stacked manner include a first doped layer, a second doped layer located on a side of the first doped layer away from the light emitting layer, and a third doped layer located on a side of the second doped layer away from the first doped layer, the materials of the first doped layer and the third doped layer include at least a second material, the second doped layer is formed by doping with the second material and a first material, and a LUMO energy level of the first material is higher than a LUMO energy level of the second material, the LUMO energy level of the second doped layer is greater than the LUMO energy levels of the first doped layer and the third doped layer; The first material and the third doping layer in the first doping layer and the third doping layer The doping ratio of the first material to the second material is 1:9 to 3.5:6.5, or the doping ratio of the first material to the second material in the second doping layer is 5:5 to 8:

2. Display panel.

2. The light-emitting structure layer further includes a hole-blocking layer, the first doped layer is located between the hole blocking layer and the second doped layer; the third doping layer is located between the second doping layer and the electron injection layer; The display panel according to claim 1 .

3. The electron mobility of the first material is greater than the electron mobility of the second material. The display panel according to claim 1 .

4. the materials of the first doping layer and the third doping layer include a second material and a first material; a doping rate of the second material in the first doping layer is greater than a doping rate of the first material, a doping rate of the first material in the second doping layer is greater than a doping rate of the second material, and a doping rate of the second material in the third doping layer is greater than a doping rate of the first material; The display panel according to claim 3 .

5. the doping ratio of the first material to the second material in the first doping layer is the same as the doping ratio of the first material to the second material in the third doping layer; and / or the doping rate of the first material in the first doped layer is less than the doping rate of the first material in the second doped layer; and / or a doping ratio of the first material in the third doping layer is smaller than a doping ratio of the first material in the second doping layer; The display panel according to claim 4.

6. the thickness of the second doping layer is between 18 nm and 30 nm; and / or the thickness of the first doping layer is between 1 nm and 5 nm; and / or The thickness of the third doping layer is 1 nm to 5 nm. The display panel according to claim 1 .

7. The vapor deposition method for a display panel according to claim 1, Placing a deposition substrate on a mounting table; a first material is placed in a first deposition cabin, a second material is placed in a second deposition cabin, the first deposition cabin and the second deposition cabin are distributed along a second direction, the first deposition cabin, the second deposition cabin and the stage are distributed at intervals along the first direction, a first opening of the first deposition cabin and a second opening of the second deposition cabin are both directed toward the substrate to be deposited, and a LUMO energy level of the first material is higher than a LUMO energy level of the second material; driving the first deposition cabin and the second deposition cabin to move from a first position to a second position along the second direction, the deposition substrate having a predetermined center in the second direction, the predetermined center extending along the first direction to form an imaginary line perpendicular to the deposition substrate, a first included angle being formed between a connection line between the first opening and the predetermined center and the imaginary line, and a second included angle being formed between a connection line between the second opening and the predetermined center and the imaginary line, the first included angle being larger than the second included angle at the first position, and the first included angle being smaller than the second included angle at the second position. Vapor deposition method.

8. driving the first deposition cabin and the second deposition cabin to move from the second position to the first position; At the first position, a distance between the first opening and the substrate to be deposited is greater than a distance between the second opening and the substrate to be deposited, and at the second position, a distance between the first opening and the substrate to be deposited is smaller than a distance between the second opening and the substrate to be deposited; The deposition method according to claim 7 .

9. The vapor deposition method for a display panel according to claim 1, Placing a deposition substrate on a mounting table; a first material is placed in a first deposition cabin, a second material is placed in a second deposition cabin, the first deposition cabin, the second deposition cabin and the stage are spaced apart from each other along a first direction, a first opening of the first deposition cabin and a second opening of the second deposition cabin are both directed toward the substrate, and a LUMO energy level of the first material is greater than a LUMO energy level of the second material; driving the first deposition cabin and the second deposition cabin to move from a third position to a fourth position along a second direction, and a first deposition rate of the first deposition cabin is different from a second deposition rate of the second deposition cabin, thereby sequentially depositing a first doping layer and a second doping layer on the deposition substrate, wherein a doping ratio of the first material in the first doping layer is smaller than a doping ratio of the second material, a doping ratio of the first material in the second doping layer is larger than a doping ratio of the second material, and a LUMO energy level of the first doping layer is smaller than a LUMO energy level of the second doping layer. Vapor deposition method.

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