CN112542489A

CN112542489A - Light emitting element

Info

Publication number: CN112542489A
Application number: CN202010959096.XA
Authority: CN
Inventors: 陈政欣; 陈慧修
Original assignee: INT Tech Co Ltd
Current assignee: INT Tech Co Ltd
Priority date: 2019-09-20
Filing date: 2020-09-14
Publication date: 2021-03-23

Abstract

The light-emitting element comprises a substrate and a light-emitting unit arranged on the substrate. The light-emitting unit comprises a first electrode, an organic light-emitting layer arranged on the first electrode, and a first electron transport layer arranged on the organic light-emitting layer and a metal-containing layer arranged on the first electron transport layer. One end of the first electron transport layer is jointed with the organic light-emitting layer and the metal-containing layer at a first joint point, one end of the organic light-emitting layer is adjacent to the first joint point and jointed with the metal-containing layer at a second joint point, and the second joint point is separated from the first joint point and is far away from the first electron transport layer. Further, at least one of the first electron transport layer and the metal-containing layer comprises a transition metal or an alkali metal.

Description

Light emitting element

Technical Field

The present invention relates to a light emitting device, and more particularly, to an organic light emitting device.

[ cross-reference to related citations ]

The present invention is a part of a U.S. patent application No. 16/122,186 filed on 5.9.2018, entitled "LIGHT EMITTING DEVICE manual METHOD AND APPARATUS for using the same" filed on the same day

Background

Organic Light Emitting Displays (OLEDs) have been widely used in most high-end electronic devices. However, due to the limitation of the prior art, the light emitting material is coated on the substrate through the mask to achieve the pixel definition, and generally the critical dimension (critical dimension) of the mask cannot be smaller than 100 μm. Therefore, a pixel density of 800ppi or more is a difficult task for OLED manufacturers.

Disclosure of Invention

In the present invention, the light emitting unit is formed of a photosensitive material. The photosensitive material is directly disposed on the substrate without a mask. The definition of the picture elements is realized by a photolithography process.

A light-emitting element comprises a substrate and a light-emitting unit arranged on the substrate. The light-emitting unit comprises a first electrode, an organic light-emitting layer arranged on the first electrode, and a first electron transport layer arranged on the organic light-emitting layer and a metal-containing layer arranged on the first transport layer. One end of the first electron transport layer is jointed with the organic light-emitting layer and the metal-containing layer at a first joint point, one end of the organic light-emitting layer is adjacent to the first joint point and jointed with the metal-containing layer at a second joint point, and the second joint point is separated from the first joint point and is far away from the first electron transport layer. Further, at least one of the first electron transport layer and the metal-containing layer comprises a transition metal or an alkali metal.

A light-emitting device includes a substrate, a plurality of bumps, a first light-emitting unit, a second light-emitting unit, and a metal-containing layer. A plurality of bumps disposed on the substrate. The first light-emitting unit and the second light-emitting unit are arranged between the bumps and arranged on the substrate, wherein the first light-emitting unit and the second light-emitting unit respectively comprise a first electrode and an organic light-emitting layer which are arranged on the first electrode; and a first electron transport layer disposed on the organic light emitting layer, wherein at least one of the first electron transport layer and the metal-containing layer comprises a transition metal or an alkali metal. And the metal-containing layer is arranged on the first electron transmission layer of the first light-emitting unit and the first electron transmission layer of the second light-emitting unit. The thickness of the first electron transport layer of the first light emitting unit is different from the thickness of the first electron transport layer of the second light emitting unit.

A light-emitting device includes a substrate, a plurality of bumps, a first light-emitting unit, a second light-emitting unit, and a metal-containing layer. A plurality of bumps disposed on the substrate. The first light-emitting unit and the second light-emitting unit are arranged between the bumps and arranged on the substrate, wherein the first light-emitting unit and the second light-emitting unit respectively comprise a first electrode and an organic light-emitting layer which are arranged on the first electrode; and a first electron transport layer disposed on the organic light emitting layer, wherein the first electron transport layer comprises a transition metal or an alkali metal. The metal-containing layer is arranged on the first electron transmission layer of the first and the second light-emitting units. The first and second light-emitting units each include a first joint and a second joint, one end of each first electron transport layer is joined to the metal-containing layer at the first joint and the corresponding organic light-emitting layer, each organic light-emitting layer has one end adjacent to the corresponding first joint, the end of each organic light-emitting layer is joined to the metal-containing layer at the second joint, and the second joint is spaced apart from the corresponding first joint and is far away from the corresponding organic light-emitting layer. The distance between the first joint point of the first light-emitting unit and the second joint point of the first light-emitting unit is different from the distance between the first joint point of the second light-emitting unit and the second joint point of the second light-emitting unit.

Drawings

Preferred embodiments of the present invention will now be described in further detail with reference to the accompanying drawings, in which:

fig. 1 shows a flexible light emitting device.

Fig. 2 is a top view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 3 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 4 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 5 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 6 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 7 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 8 shows a correlation between an aspect ratio (aspect ratio) and a height ratio (height ratio).

Fig. 9 is a top view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 10 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 11 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 12 is a cross-sectional view illustrating a portion of a flexible light emitting device according to an embodiment.

Fig. 13A to 13E illustrate an operation of manufacturing a flexible light emitting device according to an embodiment.

Fig. 14A to 14D illustrate a method of manufacturing a light emitting device according to an embodiment.

Fig. 15A to 15F illustrate a method of manufacturing a light emitting device according to an embodiment.

Fig. 16A to 16G illustrate a method of manufacturing a light emitting device according to an embodiment.

Fig. 17A is a cross-sectional view illustrating a portion of a light emitting element according to an embodiment.

Fig. 17B is a cross-sectional view illustrating a portion of a light emitting element according to an embodiment.

Fig. 18A to 18B illustrate a method of manufacturing a light emitting element according to an embodiment.

Fig. 19A to 19B illustrate a method of manufacturing a light emitting element according to an embodiment.

Fig. 20 is a sectional view illustrating a light emitting element according to an embodiment.

Fig. 21 is a top view illustrating a light emitting element according to an embodiment.

Fig. 22 is a sectional view illustrating a light emitting element according to an embodiment.

Fig. 23 is a sectional view illustrating a light emitting element according to an embodiment.

[ notation ] to show

10 electronic component

12 layers of

14 light-emitting layer

16 layers of

18 layers of

21 light emitting unit

22 light emitting unit

24 luminous pixel

140 base plate

140a surface

141 light emitting unit

145 absorbent material

201. 202 light emitting unit

204 photosensitive organic light-emitting layer

215 first electrode

220 metal composite layer

222 transition metal element

230 first type carrier injection layer

240 side wall

241 first type carrier transport layer

241a main layer

241b secondary transportation level

242 second type carrier transport layer

243 light emitting unit

243a footing

243b secondary light-emitting unit

250 base plate

251 patterned photosensitive layer/bump

251a region

252 surface

253 photoresist layer

253a opening

254 photosensitive layer

261 carrier injection layer

262 carrier transport layer

263 luminescent layer/EM layer

264 carrier transport layer

265 second electrode

266 first electron transport layer

267 metal-containing layer

2631. 2632, 2633 interface

301 buffer layer

302 photosensitive layer

312 groove

313 groove

314 cutting groove

AA line

Distance D1, D2

d clearance

e width

F1 tip

F2 turning point

Corner F3

H11, H21, H23, H31 vertical distances

h height

T11, T12, T13, T21 and T22 junction points

w width

In the X thickness direction

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following detailed description, reference is made to the accompanying drawings that form a part hereof and in which is shown by way of illustration specific embodiments of the application. In the drawings, like numerals describe substantially similar components throughout the different views. Various specific embodiments of the present application are described in sufficient detail below to enable those skilled in the art to practice the teachings of the present application. It is to be understood that other embodiments may be utilized and structural, logical or electrical changes may be made to the embodiments of the present application.

The present invention provides a light emitting device, and more particularly, an Organic Light Emitting Device (OLED) and a method for manufacturing the same. In the present invention, an organic light emitting layer is formed in an OLED by a photolithography technique. In some embodiments, the organic light emitting layer is a polymer light emitting layer. In some embodiments, the organic light emitting layer comprises a plurality of light emitting pixels.

Fig. 1 illustrates an embodiment of an electronic device 10. The electronic component 10 may be a rigid or flexible display. The electronic component 10 may have at least four different layers, substantially stacked along a thickness direction X. Layer 12 is a substrate configured to act as a platform with light emitting layer 14 thereon. Layer 16 is a capping layer over light-emitting layer 14 and layer 18 is configured to act as a window (window) for light to enter or exit from electronic element 10. In some embodiments, layer 16 is an encapsulation layer. Layer 18 may also be configured to serve as a touch interface for a user, and thus, the surface hardness may be high enough to meet design requirements. In some embodiments, layer 16 is integrated with layer 18 as one layer.

Layer 12 may be formed from a polymer matrix material. The layer 12 has a radius of curvature of no more than about 3 mm. In some embodiments, the layer 12 has a minimum bend radius of no greater than 10 mm. The minimum bend radius is measured as the internal curvature and is the minimum radius at which the layer 12 can be bent without distorting, damaging or shortening its life. In some embodiments, a plurality of conductive traces may be located in layer 12 and form a circuit to provide current to light emitting layer 14. In some embodiments, layer 12 comprises graphene (graphene).

As shown in fig. 2, the light-emitting layer 14 may be configured as an array including a plurality of light-emitting units. A cross-sectional view along line AA is shown in fig. 3. In some embodiments, layer 14 has a substrate 140. In some embodiments, the substrate is configured to provide current to the light emitting cells. In some embodiments, the light emitting unit 141 is disposed on the substrate 140 as a mesa (mesa). In some embodiments, the light emitting unit is configured to be located in a recess of the substrate 140. The thickness "h" of the light emitting cell may range from about-100 um to about 100 um. The thickness h is measured from the surface 140a of the substrate 140. A negative value indicates that the light emitting unit 141 is located in the recess. A positive value indicates that the light emitting unit 141 protrudes like a mesa (mesa) shown in fig. 3. The light emitting units 141 may be arranged in an array. Each of the independent light emitting units 141 is separated from other adjacent light emitting units 141. The gap d represents a separation distance between two adjacent light emitting units 141. In some embodiments, the gap d is between about 2nm and about 100 um. In some embodiments, the gap d is controlled to be at least not greater than about 50um, so the density of the cells can be designed to be at least greater than 700ppi or 1200 ppi.

In some embodiments, the width w of the light emitting unit 141 is between about 2nm and about 500 um. The light emitting unit 141 is a polymer material. In some embodiments, the light emitting unit 141 is photosensitive. In some embodiments, the width w is not greater than about 2 um.

FIG. 4 is a cross-sectional view of one embodiment of a light-emitting pixel 24 in a light-emitting layer. The emissive pixel 24 comprises an emissive unit 243, such as the one shown in FIG. 3. Furthermore, the light-emitting pixel 24 comprises a first type carrier transport layer 241 and a second type carrier transport layer 242. The first type is opposite to the second type. In some embodiments, the first type transport layer 241 is a Hole Transport Layer (HTL) and the second type carrier transport layer 242 is an Electron Transport Layer (ETL). In some embodiments, the first type transport layer 241 is an Electron Transport Layer (ETL) and the second type carrier transport layer 242 is a Hole Transport Layer (HTL).

In some embodiments, there are metal traces in the first type carrier transport layer 241 or the second type carrier transport layer 242. Further, the metal element may be present in the first type carrier transporting layer 241 or the second type carrier transporting layer 242. The metal element includes a transition metal. In some embodiments, the metallic element comprises one of Y, Zr, Nb, Mo, Ru, Rh, Cd, Hf, Ta, W, Re, Os.

In some embodiments, the light emitting unit 243 contacts the first type transport layer 241. In some embodiments, the light emitting unit 243 contacts the second type transport layer 242. In some embodiments, an intermediate layer is located between the light emitting unit 243 and the first type transport layer 241. In some embodiments, an intermediate layer is located between the light emitting unit 243 and the second type transport layer 242.

Fig. 5 is an enlarged view illustrating the light emitting unit 243 in fig. 4 according to an embodiment. The light emitting unit 243 has a foot 243a extending laterally from the sidewall 240 of the light emitting unit 243. The footer 243a contacts the first type transporting layer 241. The lateral extension of the footing 243a has a width e, which is measured from the sidewall 240 of the footing 243a to the tip. The tip is the point at which the foot 243a extends furthest. The tip is also the end point where the foot meets the first type transporting layer 241.

Fig. 6 is a view illustrating another embodiment of the light emitting unit 243 in fig. 4. The side wall 240 of the light emitting cell is tapered and has two different slopes (slope). The first slope is measured from the tip F1 of the foot 243a to the inflection point F2. The second slope is measured from the turning point F2 to the top angle F3 of the light emitting unit 243. In some embodiments, the second slope is greater than the first slope.

One of the purposes of the footing 243a extending from the bottom of the light emitting unit 243 is to increase the adhesion between the light emitting unit 243 and the first type transport layer 241. Since the light emitting unit 243 and the first type transport layer 241 may be formed of different materials, surface tension between the light emitting unit 243 and the first type transport layer 241 may cause unwanted peeling. By the footing 243a, a contact surface between the light emitting unit 243 and the first type transport layer 241 is increased to stabilize the light emitting unit 243 seated on the first type transport layer 241.

In some embodiments, there are some secondary light-emitting units 243b between two adjacent light-emitting units 243. The height of the secondary light emitting unit 243b is less than the height h of the light emitting unit 243. The secondary light emitting unit 243b is separated from the light emitting unit 243. In some embodiments, the height of the secondary light-emitting unit 243b is about 1/5 to about 1/15 the height of the light-emitting unit 243.

In some embodiments, the light emitting unit 243 emits light of the same wavelength as the adjacent secondary light emitting unit 243 b. In some embodiments, some of the light-emitting units are designed to emit light at a first wavelength. Some light emitting cells are designed to emit light at a second wavelength, different from the first wavelength. Some of the light emitting cells are designed to emit light of a third wavelength, which is different from the first and second wavelengths. A light emitting unit may be designated to have a secondary light emitting unit adjacent to the light emitting unit, and the light emitted from the designated secondary light emitting unit has the same wavelength as the light emitted from the corresponding light emitting unit.

An aspect ratio (aspect ratio) of the light emitting unit 243 is defined as a height h of the light emitting unit 243 divided by a gap d between two adjacent light emitting units. As shown in fig. 8, when the height ratio (height ratio) between the secondary light-emitting unit 243b and the light-emitting unit 243 reaches 1/15, the aspect ratio starts to enter the saturation region until the height ratio reaches 1/5. For ultra-high PPI (>1200PPI) displays, the designer can adjust the height ratio between the secondary light-emitting unit 243b and the light-emitting unit 243 to meet the aspect ratio requirement.

Fig. 9 is a plan view illustrating an array of light emitting units 243 on a first type transport layer 241 according to an embodiment of the present invention. The secondary light emitting unit 243b may be formed in a quadrangle, a circle, or a bar shape.

In some embodiments, the secondary light-emitting unit 243b is formed to correspond to only one pair of light-emitting units 243. The secondary light emitting unit 243b is designed to improve an aspect ratio of a gap between the pair of light emitting units 243. In some embodiments, the circular secondary light emitting unit 243b may increase the maximum aspect ratio (maximum of fig. 8) to 10% to 15% higher than the quadrilateral shape.

In some embodiments, the secondary light emitting unit 243b is formed to correspond to pairs of light emitting units. As a bar pattern on the left, the bar-shaped secondary light emitting units 243b are designed to correspond to at least three pairs of different light emitting units 243.

In some embodiments, at least two separate secondary light-emitting units 243b are formed to correspond to the pairs of light-emitting units 243. For example, two bar-shaped light emitting units on the right side, there are two parallel secondary light emitting bars (secondary light emitting strips).

In order to minimize interference between adjacent light emitting units 243, a gap between the light emitting units 243 may be filled with an absorbing material 145, as shown in fig. 10. The absorbing material 145 may absorb the light emitted by the light emitting unit 243 as well as any visible light entering the element from the surrounding environment.

In some embodiments, the first type carrier transporting layer 241 is a composite structure and includes at least a primary layer 241a and a secondary transporting layer 241b, as shown in fig. 11. There are metal traces in any sub-layer of the first type carrier transport layer 241. The metal element includes a transition metal. In some embodiments, the metallic element comprises one of Y, Zr, Nb, Mo, Ru, Rh, Cd, Hf, Ta, W, Re, Os.

Similarly, in some embodiments, the second type carrier transport layer 242 is a composite structure and includes at least a primary layer and a secondary transport layer. In any sub-layer of the second type carrier transport layer 242, there is a metal trace. The metal element includes a transition metal. In some embodiments, the metallic element comprises one of Y, Zr, Nb, Mo, Ru, Rh, Cd, Hf, Ta, W, Re, Os. In some embodiments, layer 242 may comprise Cs, Rb, K, Na, Li, Yb, Lu, Tm, and the like.

In some embodiments, there is a first type carrier injection layer adjacent to the first type carrier transport layer. As shown in fig. 12, the first-type carrier injection layer 230 is adjacent to the first-type carrier transport layer 241. Similarly, a second type carrier injection layer is adjacent to the second type carrier transport layer.

Fig. 13A to 13C illustrate some operations of manufacturing a light emitting element. In fig. 13A, a substrate including a first type carrier injection layer 230 and a composite first type carrier transport layer is provided.

In fig. 13B, a metal or metal composite layer is positioned on the composite first type carrier transport layer. The metal composite layer can be formed by various deposition processes, such as vapor deposition, sputtering, Atomic Layer Deposition (ALD), thermal evaporation, coating, or sputtering. In some embodiments, layer 220 has a thickness of about

Or smaller. Layer 220 may comprise oxygen, nitrogen, argon, fluorine, carbon, and the like.

The processing procedure is as described in fig. 13C. The treatment process may be performed by heating, microwave, plasma treatment. The treatment is applied directly on layer 220. During processing, the layer 220 is decomposed such that the transition metal elements 222 in the layer 220 can penetrate into the first type carrier transport layer (also referred to as carrier transport layer) 241. In some embodiments, the distribution of the transition metal element 222 may have a gradient. In some embodiments, the density of the transition metal element 222 on the top surface of the first-type carrier transport layer 241 is higher than the density of a location near the interface between the first-type carrier transport layer 241 and the first-type carrier injection layer 230. Likewise, the metal diffusion operation described above may be applied to the second type carrier transport layer.

After processing, the layer 220 may disappear or may be removed from the surface of the first type carrier transporting layer 241. After the treatment or removal process, the photosensitive organic light emitting layer 204 is located above the first type carrier transporting layer 241, as shown in fig. 13D.

In fig. 13E, a patterning process, such as photolithography, is performed to remove the excess portion and form the light emitting unit 243. In some embodiments, unlike the operation in fig. 13B, the metal or metal composite layer 220 is not provided before the light emitting unit 243 is formed. In one example, a light emitting unit 243 is formed above a first type carrier transporting layer 241. After the light emitting unit 243 is formed, the metal or metal composite layer 220 is disposed on the light emitting unit 243. After the metal or metal composite layer 220 is formed, the metal or metal composite layer 220 may be optionally processed. In some embodiments, a second type carrier transport layer is disposed on the light emitting unit 243 and the metal or metal composite layer 220. In some embodiments, a light emitting unit 243 is formed above the first type carrier transporting layer 241. After the light emitting unit 243 is formed, a second type carrier transport layer is disposed over the light emitting unit 243. After forming the second type carrier transporting layer, the metal or metal composite layer 220 is disposed on or over the second type carrier transporting layer. The metal or metal composite layer 220 may be selectively processed.

Fig. 14A to 14D illustrate another embodiment of forming the light emitting unit 243 on the substrate 250. In some embodiments, the substrate 250 comprises a carrier transport layer. In some embodiments, the substrate 250 includes a Thin Film Transistor (TFT) array. In fig. 14A, a patterned photosensitive layer 251 (or a photosensitive bump) is formed on a substrate 250. In some embodiments, the patterned photosensitive layer 251 is a light absorbing material, such as the light absorbing material 145 in fig. 10. In some embodiments, the patterned photosensitive layer 251 serves as a pattern definition layer. The region 251a is defined by two adjacent patterned photosensitive mesas, and the region 251a is configured to accommodate an organic light emitting unit. In some embodiments, the patterned photosensitive layer 251 is fluorine-free, i.e., substantially free of fluorine.

In fig. 14B, a photoresist layer 253 is over the photosensitive layer 251 and in the region 251 a. In some embodiments, the photoresist layer 253 contains fluorine. In fig. 14C, the photoresist layer 253 is patterned to have an opening. In some embodiments, the width of each opening 253a is less than about 10 um. In fig. 14D, the organic light emitting unit 243 is formed in the opening 253 a. In some embodiments, the height of the organic light emitting unit 243 is less than the height of the photosensitive layer 251. In another step (not shown), the photoresist layer 253 can be removed.

In fig. 15A, a substrate 250 is provided, and the substrate 250 may include a Thin Film Transistor (TFT) array. A plurality of first electrodes 215 are disposed on the substrate 250. Each of the first electrodes 215 is configured such that one side is connected to a circuit embedded in the substrate 250 and the other side contacts the light emitting material. The array pattern of the first electrodes is designed in consideration of the arrangement of the pixels. A photosensitive layer 254 is disposed on the first electrode 215 and the substrate 250. In some embodiments, a photosensitive layer 254 is coated on the first electrode 215 and the substrate 250.

The photosensitive layer 254 fills the gap between the adjacent first electrodes 215. The photosensitive layer 254 is heated to a predetermined temperature and then exposed to a specified wavelength. The photoactive layer 254 absorbs more than 90% of visible light and is also referred to as a blackbody material in the present disclosure. After exposure, the photosensitive layer 254 is wetted in a solution for development. As shown in fig. 15B, a portion of the photosensitive layer 254 is removed, and the remaining portion substantially covers the gap between the adjacent first electrodes 215. In the cross-sectional view, the remaining photosensitive layer 254 forms a plurality of bumps 251, and each bump 251 fills the gap between adjacent first electrodes 215. The bumps 251 partially cover the respective first electrodes 215. The patterned bumps 251 are also called a Pixel Defined Layer (PDL).

The bumps 251 may be formed in different shapes. In fig. 15B, the bump 251 has a curved surface. In some embodiments, the shape of the bump 251 is trapezoidal. After the bump 251 is formed, a cleaning operation is performed to clean the bump 251 and the exposed surface of the first electrode 215. In one embodiment, the deionized water is heated to a temperature between 30 ℃ and 80 ℃ during the cleaning operation. After the temperature of the di water is raised to a predetermined temperature, the di water is introduced to the bump 251 and the exposed surface of the first electrode 215.

In some embodiments, ultrasonic waves are used during the cleaning operation. The ultrasonic waves are introduced into a cleaning agent (e.g., water or isopropyl alcohol (IPA)). In some embodiments, carbon dioxide is introduced into the cleaning agent. After the cleaning operation, the cleaning agent is removed from the exposed surface by a heating operation. During the heating operation, the substrate 250 and the bumps 251 may be heated to a temperature between 80 ℃ and 110 ℃. In some examples, compressed air is directed to the exposed surfaces to help remove residues of the cleaning agent while heating.

After the heating operation, the exposed surface may be treated using O2, N2, or Ar plasma. The plasma is used to roughen the exposed surface. In some embodiments, ozone is used to adjust the surface condition of the exposed surface.

As shown in fig. 15C, a carrier injection layer 261 is disposed on the exposed surfaces of the bump 251 and the first electrode 215. The carrier-implanted layer 261 is continuously lined along the exposed surface. More specifically, the exposed surface of each first electrode 215 is configured to be an effective light emitting area of a light emitting unit. In this embodiment, a common carrier injection layer 261 is used for all light emitting cells. In some embodiments, carrier injection layer 261 is for hole injection. In some embodiments, the light emitting cells are arranged in at least three different groups, each group emitting light of a different color than the other groups, two of the at least three different groups share a common second-type carrier injection layer 261, and the remaining one group of second-type carrier injection layer 261 and the two groups are not common. In some embodiments, the red and green groups of light emitting cells use a common carrier transport layer 262, and the blue group of light emitting cells use a carrier transport layer 262, the carrier transport layer 262 being independent of the common carrier transport layer 262. In some embodiments, the carrier injection layer 261 is for electron injection. The carrier injection layer 261 continuously covers the plurality of bumps 251 and the first electrode 215. Optionally, carrier implant layer 261 is in contact with bumps 251. In one embodiment, the carrier injection layer 261 is in contact with the first electrode 215. In some embodiments, carrier injection layer 261 is organic.

As shown in fig. 15D, a carrier transport layer 262 (or first type carrier transport layer) is disposed on the exposed surfaces of the bump 251 and the first electrode 215. The carrier injection layer 261 is disposed below the carrier transport layer 262. Carrier transport layer 262 is continuously lined along carrier injection layer 261. In this embodiment, a common carrier transport layer 262 is used for all light emitting units. In some embodiments, the light-emitting units are arranged in at least three different groups, each group emitting light of a different color than the other groups, two of the at least three different groups share a common carrier transport layer 262, and the remaining one group of carrier transport layers 262 is different from the other two groups. In some embodiments, the red and green groups of light emitting cells use a common carrier transport layer 262, and the blue group of light emitting cells use a carrier transport layer 262, the carrier transport layer 262 being independent of the common carrier transport layer 262. In some embodiments, carrier transport layer 262 is for hole transport. In some embodiments, carrier transport layer 262 is for electron transport. The carrier transporting layer 262 continuously covers the bumps 251 and the first electrode 215. Optionally, carrier transport layer 262 is in contact with carrier injection layer 261. In some embodiments, carrier transport layer 262 is organic.

In some embodiments, as shown in fig. 15E, carrier transport layer 262 is configured as a segment, while carrier implant layer 261 lines continuously along exposed bump 251 and first electrode 215. Each segment is arranged perpendicularly with respect to one of the first electrodes 215. In other words, carrier transport layer 262 is not continuously lined along carrier injection layer 261. Each light-emitting unit has a respective carrier transport layer 262 disposed thereon.

In some embodiments, as shown in fig. 15F, the carrier injection layer 261 is configured as a segment, while the carrier transport layer 262 lines continuously along the exposed bump 251 and the first electrode 215. Each segment is arranged perpendicularly with respect to one of the first electrodes 215. In other words, the carrier injection layer 261 is not continuously lined along the exposed bump 251 and the first electrode 215. Each light emitting cell has a respective carrier injection layer 261 disposed thereon.

As shown in fig. 16A, the buffer layer 301 is disposed on the bump 251 and also covers the carrier injection layer 261 and the carrier transport layer 262. The buffer layer 301 is used to block moisture from penetrating into the bump 251, the carrier injection layer 261, and the carrier transport layer 262. In an embodiment, the buffer layer 301 is provided by spin coating. Buffer layer 301 may be further heated to a temperature T1. In some embodiments, T1 is about 5 ℃ to about 10 ℃ below the glass transition temperature of carrier injection layer 261 and carrier transport layer 262. This heating operation is carried out for about 1 to 10 minutes. In some embodiments, buffer layer 301 comprises fluorine.

In 16B, after the heating operation, the photosensitive layer 302 is disposed on the buffer layer 301. The photosensitive layer 302 may be further patterned by a photolithography process such that a portion of the buffer layer 301 is exposed through the recess 312. In fig. 16C, a portion of the buffer layer 301 is removed to have a groove 313, exposing the carrier transport layer 262. In some embodiments, the removal operation of fig. 16C is performed by wet etching.

For some embodiments, the removing operation includes at least two steps. The first step is a vertical removal, which cuts the buffer layer 301 substantially according to the size of the opening width of the groove 312, as shown in fig. 16C. After the formation of the groove 313, a second step is performed to perform lateral removal, as shown in fig. 16D. The undercut 314 is formed such that the groove 313 extends further into the buffer layer 301 to expose more of the surface toward the highest point of the bump 251.

An organic light Emitting (EM) layer 263 is disposed in the groove 313 and covers the carrier transport layer 262 and the photosensitive layer 302. In fig. 16E, the EM layer 263 completely covers the exposed carrier transport layer 262. The EM layer 263 is configured to emit a first color.

As shown in fig. 16F, an organic carrier transport layer 264 (or a second type carrier transport layer) is disposed on the EM layer 263. The organic carrier transport layer 264 may be a hole or electron transport layer 264. In some embodiments, organic carrier transport layer 264 and carrier transport layer 262 are each configured in opposite valence states.

In fig. 16G, a second electrode 265 is disposed on the organic carrier transport layer 264. The top surface of the photosensitive layer 302 is also covered by the second electrode 265. After the second electrode 265 is formed, the photosensitive layer 302 may be removed. The second electrode 265 may be a metal material, such as Ag, Mg, or the like. In some embodiments, the second electrode 265 includes ITO (indium tin oxide) or IZO (indium zinc oxide). In some embodiments, each light-emitting unit has an independent second electrode 265 when viewed in cross-section, and the plurality of light-emitting units share a common carrier transport layer 264.

The operations shown in fig. 16A to 16G may be repeatedly performed to form light emitting units of different colors. Fig. 17A illustrates another light emitting unit emitting a second color different from the first color. The second electrodes 265 of the first light emitting unit 21 and the second light emitting unit 22 are continuous. Each light-emitting unit has a separate carrier transport layer 264. The individual carrier transport layers 264 are segmented into a plurality of segments, and each segment is disposed on one light emitting unit. In some embodiments, a plurality of light emitting units share a common carrier transport layer 264. In some embodiments, the light emitting units are arranged in at least three different groups, each group emitting light of a different color than the other groups, two of the at least three different groups share a common carrier transport layer 264, and the remaining group of carrier transport layers 264 are different from the other two groups. In some embodiments, the red and green groups of light emitting cells use a common carrier transport layer 262, and the blue group of light emitting cells use a carrier transport layer 262, the carrier transport layer 262 being independent of the common carrier transport layer 262.

As shown in fig. 17B, in some embodiments, each light emitting cell has an independent carrier transport layer 262 (closer to the first electrode 215 than the carrier transport layer 264). The carrier transport layer 262 is segmented into a plurality of segments, and each segment is disposed on one of the light emitting units. In some embodiments, a plurality of light emitting units share a common carrier transport layer 262. Each light emitting cell has an independent carrier injection layer 261. The individual carrier injection layer 261 is segmented into a plurality of segments, and each segment is disposed on one light emitting cell. In some embodiments, a plurality of light emitting cells share a common carrier injection layer 261.

In some embodiments, the second carrier transport layer 264 has at least two sub-layers. The first secondary layer is between the second secondary layer and EM layer 264. In some embodiments, the second secondary layer is between the first secondary layer and the second electrode 265. In some embodiments, both secondary layers are continuous, while light emitting cells 21 and 22 use common first and second secondary layers. In some embodiments, one secondary layer is segmented and the other secondary layer is continuous. In some embodiments, the first secondary layer is continuous and the second secondary layer is segmented. Each light emitting cell has an independent second secondary layer. In some embodiments, the second secondary layer is continuous and the first secondary layer is segmented. Each light emitting unit has an independent first secondary layer.

As shown in fig. 18A, after the operation shown in fig. 16E is performed, the metal or metal composite layer 220 is disposed over the light emitting layer 263. The metal or metal composite layer 220 may be provided by a variety of processes, such as vapor deposition, liquid spraying, or printing. After the metal or metal composite layer 220 is disposed, a treatment may be optionally performed to introduce the metal or metal composite layer 220 into the light-emitting layer 263, as shown in fig. 18B. Then, the second-type carrier transport layer 264 is disposed over the light emitting unit 243 and the metal or metal composite layer 220. Similarly, reference may be made to the above description for the arrangement of each layer of each light-emitting unit being independent or shared with other light-emitting units, and the embodiments shown in the figures should not be taken as limiting.

As shown in fig. 19A, after performing the operation shown in fig. 16F, the metal or metal composite layer 220 is disposed on the second type carrier transporting layer 264. The metal or metal composite layer 220 may be provided by a variety of processes, such as vapor deposition, liquid spraying, or printing. After the metal or metal composite layer 220 is disposed, a process may optionally be performed to introduce the metal or metal composite layer 220 into the second type carrier transport layer 264, as shown in fig. 19B. Similarly, reference may be made to the above description for the arrangement of each layer of each light-emitting unit independently or in common with other light-emitting units, and the embodiments shown in the figures should not be taken as limiting.

FIGS. 20-21 illustrate another embodiment of a light emitting device. Fig. 20 is a cross-sectional view of a light emitting element according to an aspect of some embodiments of the present disclosure. The light emitting device includes a substrate 250, a plurality of bumps 251 disposed on the substrate 250, and a light emitting unit 201 disposed between the bumps 251 and on the substrate 250.

The light emitting unit 201 includes an electrode 215, an organic light emitting layer 263 disposed on the electrode 215, and a first electron transporting layer 266 disposed on the organic light emitting layer 263. The light emitting cell 201 also has a metal-containing layer 267 disposed on the first electron transport layer 266. It should be noted that the electron transport layer used herein is only an example, and the present invention is not limited to the application of other different types of carriers, such as holes and the like.

As can be seen from the cross-sectional view, the first end of the first electron transport layer 266 is bonded to the metal-containing layer 267 at the first junction T11 and the organic light emitting layer 263. The first end of the organic light emitting layer 263 is adjacent to the first junction T11, and the first end of the organic light emitting layer 263 is bonded to the metal-containing layer 267 at the second junction T21. The organic light emitting layer 263 also has a second end. The first end of the organic light emitting layer 263 is closer to the point T11 than the second end. The point T21 is spaced apart from the point T11 and is remote from the first electron transport layer 266. In some cases, point T21 is closer to the apex of bump 251 than point T11.

The interface 2631 is disposed between the metal-containing layer 267 and the organic light-emitting layer 263. Interface 2631 ranges from point T11 to point T21. In some embodiments, the vertical distance between the second junction point T21 and the substrate 250 is greater than or equal to the vertical distance between the point T11 and the substrate 250.

Similarly, the first electron transport layer 266 has a second end opposite to the first end, and is bonded to the organic light emitting layer 263 and the metal-containing layer 267 at a first junction T12. The second end of the organic light emitting layer 263 is adjacent to the point T12 and is joined to the metal containing layer 267 at a second junction T22. The point T22 is spaced apart from the point T12 and away from the first electron transport layer 266. In some cases, point T22 is closer to the apex of bump 251 than point T12.

Similarly, another interface 2632 is located between the metal-containing layer 267 and the organic light-emitting layer 263. The interface 2632 ranges from point T12 to point T22. In some embodiments, the

interfaces

2631 and 2632 are located at opposite ends of the organic light-emitting layer 263. In some embodiments, the perpendicular distance between point T22 and substrate 250 is greater than or equal to the perpendicular distance between point T12 and substrate 250.

Fig. 21 is a top view of the light emitting unit 201 shown in fig. 20 (the cross section of fig. 20 is taken along line B-B of fig. 21). The

interfaces

2631 and 2632 are configured as rectangles, however, may take different shapes depending on the preference of the designer. The surface area of each interface is determined by the distance between the points T11, T21 and their corresponding points T21, T22 at the same end. The surface area of the interface 2631 and the surface area of the interface 2632 may be the same or different.

Another interface 2633 between the organic light-emitting layer 263 and the metal-containing layer 267 is shown in FIG. 21.

Interfaces

2631, 2632, and 2633 may merge into a continuous loop. The ring pattern is located at the periphery of the organic light emitting layer 263. The width of the annular pattern may be non-uniform and may be different in different sections. For example, the width of the interface 2631 may be different than the width of the interface 2632 in the same ring. In some embodiments, the ring of organic light emitting layer 263 surrounds first electron transport layer 266. Joints T11 and T21 are boundaries of the interface 2633 as viewed from above.

Referring again to fig. 20, in some embodiments, each bump 251 has a surface 252 that protrudes away from the substrate 250. The surface 252 of the bump 251 may be curved. An end of the organic light emitting layer 263 may extend toward an apex of the bump 251 and be disposed on a portion of the surface 252 of the bump 251.

In some embodiments, a carrier (of the opposite type as the carrier of the transmission layer 266) implant layer 261 is disposed on and continuously lines the bump 251 and the surface 252 of the first electrode 215. In some embodiments, a carrier transport layer 262 (of the same carrier type as the injection layer 261) is provided on the carrier injection layer 261 and continuously lined, and an organic light emitting layer 263 is provided on the carrier transport layer 262. In some embodiments, the carrier injection layer 261 is a hole injection layer. In some embodiments, carrier transport layer 262 is a hole transport layer. In some embodiments, the metal-containing layer 267 is in contact with the organic light-emitting layer 263, the first transport layer 266, and the carrier transport layer 262. In some embodiments, the metal-containing layer 267 is bonded to the organic light-emitting layer 263 and the carrier transport layer 262 at points T21, T22.

In some embodiments, the first distance D1 between the first junction T11 and the second junction T21 is greater than zero. In some embodiments, the second distance D2 between the first junction T12 and the second junction T22 is equal to or greater than 0. The second distance D2 may be similar to the first distance D1. The second distance D2 may be different from the first distance D1. In some embodiments, the vertical distance between the second junction T21 and the substrate 250 may be similar to or different from the vertical distance between the second junction T22 and the substrate 250.

The thickness of the first electron transport layer 266 is greater than the thickness of the metal-containing layer 267. In some embodiments, the ratio between the thickness of the metal-containing layer 267 and the thickness of the first electron transport layer 266 is 0.1 and 0.7. The thickness of the metal-containing layer 267 can be between 0.1 and 50 nm. In some embodiments, the thickness of the metal-containing layer 267 is in the range of 0.1 to 5 nm.

In some embodiments, the thickness of the first electron transport layer 266 is non-uniform compared to the thickness of the metal-containing layer 267. The top surface of the first electron transport layer 266 can be roughened as compared to the top surface of the metal-containing layer 267. In some embodiments, the interface between the first electron transporting layer 266 and the metal-containing layer 267 undulates compared to the interface between the first electron transporting layer 266 and the organic light-emitting layer 263 between the points T11 and T12. The uniformity of the metal-containing layer 267 may be better than the uniformity of the first electron transport layer 266. In some embodiments, the metal-containing layer 267 is conformal with the underlying layers including the first electron transport layer 266, the periphery of the organic light emitting layer 263, and the carrier transport layer 262 disposed on the bump 251. In some embodiments, the

interfaces

2631, 2632 of the organic light-emitting layer 263 are rough compared to the interfaces between the first electron-transporting layer 266 and the organic light-emitting layer 263 at the point T11 to the point T12.

At least one of the first electron transport layer 266 and the metal-containing layer 267 comprises a transition metal or an alkali metal. In some embodiments, at least one of the first electron transport layer 266 and the metal-containing layer 267 comprises a material selected from the group consisting of: alkali metal halide salts, alkali metal oxides, alkali metal coordination complexes, alkaline earth metal carbonates, Yb, alkali metals, alkaline earth metals, and transition metals. In some embodiments, at least one of the first electron transport layer 266 and the metal-containing layer 267 further comprises an organic material. Embodiments of the organic material may have a resonant structure. The organic material may be benzimidazole. In some embodiments, at least one of the first electron transport layer 266 and the metal-containing layer 267 comprises an organic material and an alkali metal coordination complex. In some embodiments, at least one of the first electron transport layer 266 and the metal-containing layer 267 comprises benzimidazole and a lithium coordination complex. In some embodiments, at least one of the first electron transport layer 266 and the metal-containing layer 267 comprises

And

in some embodiments, the first electron transport layer 266 and the metal-containing layer 267 comprise the same material.

In some embodiments, the first electron transport layer 266 is configured to transport and inject electrons. In some embodiments, the metal-containing layer 267 is configured for electron transport and electron injection. In some embodiments, the metal-containing layer 267 is a second electron transport layer. In some embodiments, metal-containing layer 267 is an electron injection layer.

In some embodiments, a second electrode 265 (of the opposite type to the first electrode 215) is disposed on the metal-containing layer 267. The upper surface of the metal-containing layer 267 may be covered with the second electrode 265. In some embodiments, the light emitting unit 201 further includes an electron injection layer. When the metal-containing layer 267 is used for electron transport, an electron injection layer may be disposed in the second electrode 265 and the metal-containing layer 267. An electron injection layer may be disposed over and continuously lining the surface of metal-containing layer 267.

FIG. 22 is a cross-sectional view of another embodiment of a light emitting device. Referring to fig. 22, in some embodiments, a light emitting device includes a substrate 250, bumps 251 disposed on the substrate 250, a first light emitting unit 201 and a second light emitting unit 202 disposed between the bumps 251 and on the substrate 250.

The first light emitting unit 201 is as described above with reference to fig. 20 and 21, and the second light emitting unit 202 is configured similarly to the first light emitting unit 201. In addition, although the first and second

light emitting units

201 and 202 are shown to have similar functions, they are only exemplary and are not intended to limit the embodiments of the present invention. The first and second

light emitting units

201, 202 may have similar structures or different structures in order to meet the desired functional requirements.

The first light emitting unit 201 and the second light emitting unit 202 differ at least in the thickness of the first electron transport layer 266 thereof. In other words, the thickness of the first electron transport layer 266 of the first light emitting unit 201 and the thickness of the first electron transport layer 266 of the second light emitting unit 202 are different. In some embodiments, the first light emitting unit 201 and the second light emitting unit 202 differ at least in the thickness uniformity of the first electron transport layer 266 thereof. In some embodiments, the first electron transport layer 266 of the first light emitting unit 201 is thicker than the second light emitting unit 202, and the uniformity of the thickness of the first electron transport layer 266 of the first light emitting unit 201 is less than the uniformity of the thickness of the first electron transport layer 266 of the second light emitting unit 202.

The first and second light emitting

cells

201, 202 may have a metal-containing layer 267 disposed on the first electron transport layer 266 of the first and second light emitting

cells

201, 202. The light emitting device further includes a second electrode 265 disposed on the metal-containing layer 267. In some embodiments, the light emitting device further comprises a carrier (opposite to the carrier type of the transmission layer 266) injection layer 261 disposed on and continuously lining the bump 251 and the first electrode 215. In some embodiments, the light emitting device further comprises a carrier transporting layer 262 (of the same carrier type as the injection layer 261) disposed on the carrier injection layer 261 and continuously lining. The organic light emitting layer 263 can be disposed between the carrier transporting layer 262 and the corresponding first electron transporting layer 266.

In some embodiments, the first light emitting unit 201 and the second light emitting unit 202 are adjacent to each other. In some embodiments, the light emitting device includes a plurality of light emitting units, and the first and second

light emitting units

201 and 202 may be any two of the light emitting units. One of ordinary skill in the art can readily appreciate that any suitable number of light-emitting units can alternatively be used, and all such combinations are intended to be within the scope of the present embodiments.

In some embodiments, the metal-containing layer 267 is divided into a plurality of sections, and each section is disposed in a light-emitting unit. In some embodiments, the first and second light emitting

cells

201, 202 share a common metal-containing layer 267. The metal-containing layer 267 is disposed on the bump 251 and the first electron transport layer 266 of the first and second

light emitting units

201 and 202. In some embodiments, the second electrode 265 is divided into a plurality of sections, and each section is disposed in a light emitting unit. In some embodiments, the first and second light emitting

cells

201, 202 share a second electrode 265.

In some embodiments, the first light emitting unit 201 is configured to display a first color, and the second light emitting unit 202 is configured to display a second color different from the first color. The thickness of the first electron transport layer 266 may be related to the color displayed by the corresponding light emitting cell. In some embodiments, the second color is red or blue when the first color is green, or the second color is blue when the first color is red. The first electron transport layer 266 of the first light emitting unit 201 is thinner than the first electron transport layer 266 of the second light emitting unit 202.

The first and second light emitting

cells

201 and 202 respectively include a first junction point T11 and a first junction point T13. Each of the points T11 and T13 is an end of the first electron transporting layer 266 that is bonded to the corresponding organic light emitting layer 263 and the metal-containing layer 267. In some embodiments, the first and second light emitting

cells

201 and 202 each include two first junctions T11 and T13, which are located at opposite ends of the first electron transport layer 266 when viewed in cross section.

In some embodiments, the perpendicular distance H11 between the point T11 and the substrate 250 and the perpendicular distance H31 between the point T13 and the substrate 250 are different due to the different thicknesses of the first electron transport layer 266. In some embodiments, each of the points T11, T13 is an end of the first electron transporting layer 266 that is joined to the corresponding organic light emitting layer 263, carrier transporting layer 262, and metal-containing layer 267.

Fig. 22 is a cross-sectional view of a light emitting device in some embodiments. Referring to fig. 22, in some embodiments, the first and second light emitting

cells

201 and 202 further include a second junction T21 and T23, respectively. Each of the organic light emitting layers 263 has one end closer to the corresponding point T11, T13. The above-mentioned end of each organic luminescent layer 263 is joined to the metal-containing layer 267 at the corresponding points T21, T23. Each point T21, T23 is spaced apart from the corresponding point T11, T13 and away from the corresponding organic light emitting layer 263. In some embodiments, the first and second light emitting

cells

201 and 202 have two second junctions T21 and T23, respectively, at opposite ends of the organic light emitting layer 263.

In some embodiments, each of the first and second light-emitting

units

201, 202 includes an interface between the corresponding organic light-emitting layer 263 and the metal-containing layer 267. One interface is located between point T11 and point T21, and the other interface is located between point T13 and point T23. In some embodiments, the perpendicular distance H21 between the point T21 and the substrate 250 is different from the perpendicular distance H23 between the point T23 and the substrate 250.

In certain embodiments, the distance between point T11 and point T21 is different from the distance between point T13 and point T23.

In some embodiments, the light emitting device further comprises a third light emitting unit. The third light emitting unit is arranged similarly to the first light emitting unit 201. The first, second and third light emitting units differ from each other by at least the thickness of the first electron transport layer 266.

In some embodiments, the light emitting cells are grouped into at least three different groups, and each group emits a different color than the other groups. The thickness of the first electron transport layer 266 may be related to the color displayed by the corresponding light emitting cell. In some embodiments, the first light emitting unit 201 emits green light, and the first electron transport layer 266 of the first light emitting unit is the thinnest compared to other first electron transport layers 266 configured to emit different colors. In some embodiments, the second light emitting unit 202 emits green light, and the thickness of the first electron transport layer 266 of the second light emitting unit 202 is between the thickness of the first electron transport layer 266 of the first light emitting unit 201 and the thickness of the first electron transport layer 266 of the third light emitting unit compared to the other first electron transport layers 266 for emitting different colors. In some embodiments, the third light emitting unit emits blue light, and the thickness of the first electron transport layer 266 of the third light emitting unit is the thickest compared to other first electron transport layers 266 for emitting different colors.

The foregoing outlines features of some embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present invention as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

The above embodiments are provided only for illustrating the present invention and not for limiting the present invention, and those skilled in the art can make various changes and modifications without departing from the scope of the present invention, and therefore, all equivalent technical solutions should fall within the scope of the present invention.

Claims

1. A light emitting element comprising:

a substrate; and

a light emitting unit disposed on the substrate, wherein the light emitting unit comprises:

a first electrode;

an organic light-emitting layer arranged on the first electrode;

a first electron transport layer disposed on the organic light emitting layer, and

a metal-containing layer disposed on the first electron transport layer;

wherein one end of the first electron transport layer is bonded to the organic light emitting layer and the metal-containing layer at a first junction, one end of the organic light emitting layer is adjacent to the first junction and is bonded to the metal-containing layer at a second junction, and the second junction is spaced apart from the first junction and is far away from the first electron transport layer; and

wherein at least one of the first electron transport layer and the metal-containing layer comprises a transition metal or an alkali metal.

2. The light-emitting device according to claim 1, wherein the organic light-emitting layer comprises an interface between the metal-containing layer and the organic light-emitting layer, the interface being between the first junction and the second junction.

3. The light-emitting device according to claim 1, wherein a distance between the second bonding point and the substrate is greater than a distance between the first bonding point and the substrate.

4. The light-emitting device according to claim 1, wherein the first electron-transporting layer and the metal-containing layer comprise the same material.

5. The light-emitting device according to claim 1, wherein the metal-containing layer is a second electron-transporting layer.

6. The light-emitting device according to claim 1, wherein the metal-containing layer is an electron injection layer.

7. The light-emitting device according to claim 1, wherein the first electron-transporting layer of the light-emitting unit comprises a material selected from the group consisting of: alkali metal halide salts, alkali metal oxides, alkali metal coordination complexes, alkaline earth metal carbonates, Yb, alkali metals, alkaline earth metals, and transition metals.

8. The light-emitting device according to claim 1, wherein a ratio of a thickness of the metal-containing layer to a thickness of the first electron transport layer is between 0.1 and 0.7.

9. The light-emitting device according to claim 1, wherein the first electron-transporting layer has a thickness uniformity greater than that of the metal-containing layer.

10. A light emitting element comprising:

a substrate;

a plurality of bumps disposed on the substrate;

a first light-emitting unit and a second light-emitting unit disposed between the bumps and on the substrate, wherein each of the first and second light-emitting units comprises a first electrode and an organic light-emitting layer disposed on the first electrode; and a first electron transport layer disposed on the organic light emitting layer, at least one of the first electron transport layer and the metal-containing layer containing transition metal or alkali metal; and

a metal-containing layer disposed on the first electron transport layer of the first and second light-emitting units;

wherein the thickness of the first electron transport layer of the first light emitting unit is different from the thickness of the first electron transport layer of the second light emitting unit.

11. The light-emitting device according to claim 10, wherein each of the first electron-transporting layers has an end, the end of each of the first electron-transporting layers is bonded to the corresponding organic light-emitting layer and the metal-containing layer at a first bonding point, and a vertical distance between the first bonding point of the first light-emitting unit and the substrate is different from a vertical distance between the first bonding point of the second light-emitting unit and the substrate.

12. The light-emitting device of claim 11, wherein each of the organic light-emitting layers has an end adjacent to the corresponding first junction, the end of the organic light-emitting layer is bonded to the metal-containing layer at a second junction, and each of the second junctions is spaced apart from the corresponding first junction and is remote from the corresponding first electron-transporting layer.

13. The light-emitting device according to claim 12, wherein a vertical distance between the second bonding point of the first light-emitting unit and the substrate is different from a vertical distance between the second bonding point of the second light-emitting unit and the substrate.

14. The light-emitting device according to claim 10, wherein a thickness of the first electron-transporting layer of the first light-emitting unit is greater than a thickness of the second light-emitting unit, and a thickness uniformity of the first electron-transporting layer of the first light-emitting unit is less than a thickness uniformity of the first electron-transporting layer of the second light-emitting unit.

15. The light-emitting device according to claim 10, wherein the metal-containing layer is disposed on the bumps and the first electron transport layer of the first and second light-emitting units.

16. The light-emitting device according to claim 10, wherein the first light-emitting unit is configured to display a first color, and the second light-emitting unit is configured to display a second color different from the first color.

17. A light emitting element comprising:

a substrate;

a plurality of bumps disposed on the substrate;

a first light-emitting unit and a second light-emitting unit disposed between the bumps and on the substrate, wherein each of the first and second light-emitting units comprises a first electrode and an organic light-emitting layer disposed on the first electrode; and a first electron transport layer disposed on the organic light emitting layer, wherein the first electron transport layer comprises a transition metal or an alkali metal; and

wherein each of the first and second light-emitting units comprises a first junction and a second junction, one end of each of the first electron-transporting layers is joined to the metal-containing layer at the first junction and the corresponding organic light-emitting layer, each of the organic light-emitting layers has one end adjacent to the corresponding first junction, the one end of each of the organic light-emitting layers is joined to the metal-containing layer at the second junction, and the second junction is spaced apart from the corresponding first junction and is away from the corresponding organic light-emitting layer;

the distance between the first joint point of the first light-emitting unit and the second joint point of the first light-emitting unit is different from the distance between the first joint point of the second light-emitting unit and the second joint point of the second light-emitting unit.

18. The light-emitting device according to claim 17, wherein the metal-containing layer is disposed on the bumps and the first electron-transporting layer of the first and second light-emitting units.