TWI867521B - Light emitting device structure and operation method thereof - Google Patents

Abstract

A light emitting device structure including a first light emitting element and a second light emitting element is provided. The first light emitting element includes a first anode and a first cathode. The second light emitting element is stacked on the first light emitting element and includes a second anode and a second cathode, wherein the second cathode is electrically connected to the first anode. An operation method of the light emitting device structure is also provided.

Description

Light emitting device structure and operation method thereof

The present invention relates to a light-emitting device structure and an operating method thereof.

In traditional LED display panels, LEDs of multiple colors are placed on the same plane with circuits (including drive components and wires) to achieve full-color display. However, as the resolution increases, the LEDs of multiple colors are placed closer and closer, making the circuits too crowded and difficult to manufacture. In addition, placing LEDs of multiple colors on the same plane will occupy a larger area, making it difficult to improve the resolution.

The present invention provides a light-emitting device structure and an operating method thereof, which helps to improve resolution or reduce manufacturing difficulty.

In one embodiment of the present invention, the light-emitting device structure includes a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first anode and a first cathode. The second light-emitting element is stacked on the first light-emitting element and includes a second anode and a second cathode, wherein the second cathode is electrically connected to the first anode.

In another embodiment of the present invention, the operation method of the light-emitting device structure includes the following steps. A light-emitting device structure is provided, the light-emitting device structure includes a first light-emitting element and a second light-emitting element; the first light-emitting element includes a first anode and a first cathode; the second light-emitting element is stacked on the first light-emitting element and includes a second anode and a second cathode, wherein the second cathode is electrically connected to the first anode. The voltage difference between the first anode and the first cathode is made greater than a first value, so that the first light-emitting element emits a first color light. The voltage difference between the second anode and the second cathode is made greater than a second value, so that the second light-emitting element emits a second color light, wherein the second color light and the first color light are different colors.

In order to make the above features and advantages of the present invention more clearly understood, the following is a detailed description of the embodiments with the accompanying drawings.

The directional terms mentioned in this article, such as "up", "down", "front", "back", "left", "right", etc., are only for reference to the directions of the attached drawings. Therefore, the directional terms used are for explanation and are not used to limit the present invention.

In the accompanying drawings, each diagram depicts the general characteristics of the methods, structures or materials used in a particular embodiment. However, these diagrams should not be interpreted as defining or limiting the scope or nature covered by these embodiments. For example, the relative size, thickness and position of each film layer, region or structure may be reduced or exaggerated for clarity.

In the following embodiments, the same or similar components will be labeled with the same or similar reference numerals, and their redundant description will be omitted. In addition, the features in different embodiments can be combined with each other without conflict, and simple equivalent changes and modifications made according to this specification or the scope of the patent application are still within the scope of this patent.

The terms "first", "second", etc. mentioned in this specification or patent application are only used to name different components or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of components, nor to limit the manufacturing order or setting order of the components. In addition, a component/film layer disposed on (or above) another component/film layer can cover the case where the component/film layer is directly disposed on (or above) the other component/film layer, and the two components/film layers are in direct contact; and the case where the component/film layer is indirectly disposed on (or above) the other component/film layer, and there are one or more components/film layers between the two components/film layers.

Figures 1 to 5, Figure 7, Figure 8 and Figure 10 are schematic diagrams of light-emitting device structures according to multiple embodiments of the present disclosure. Figure 6 is a schematic diagram of a top view of the light-emitting device structure of Figure 5. Figure 9 is a schematic diagram of a top view of the light-emitting device structure of Figure 8.

Referring to FIG. 1 , the light-emitting device structure 1 may include a first light-emitting element 10 and a second light-emitting element 12 stacked on the first light-emitting element 10, but is not limited thereto. According to different requirements, the light-emitting device structure 1 may also include other elements and/or film layers.

Taking the structure of a full-color light-emitting device as an example, the first light-emitting element 10 may be a single-color light-emitting element, and the second light-emitting element 12 may be a dual-color light-emitting element, but the present invention is not limited thereto. In other embodiments, the first light-emitting element 10 may be a dual-color light-emitting element, and the second light-emitting element 12 may be a single-color light-emitting element. The single-color light-emitting element may be a red light-emitting element, a green light-emitting element, or a blue light-emitting element, and correspondingly, the dual-color light-emitting element may be a green-blue light-emitting element, a blue-red light-emitting element, or a red-green light-emitting element. For the convenience of explanation, the single-color light-emitting element is a red light-emitting element and the dual-color light-emitting element is a green-blue light-emitting element.

The first light-emitting element 10 may include a first anode 100 and a first cathode 102. The first anode 100 and the first cathode 102 are made of a conductive material. The conductive material may include a transparent conductive material (such as metal oxide or graphene, etc.) or a non-transparent conductive material (such as metal or alloy, etc.). The top-view shapes of the first anode 100 and the first cathode 102 may not be limited. For example, the top-view shapes of the first anode 100 and the first cathode 102 may be block-shaped, strip-shaped, sheet-shaped, frame-shaped, ring-shaped or irregular. In addition, the first anode 100 and the first cathode 102 may have the same or different top-view shapes.

According to different requirements, the first light-emitting element 10 may also include other elements and/or film layers. For example, the first light-emitting element 10 may also include a first semiconductor material layer 104, and the first anode 100 and the first cathode 102 are disposed on the first semiconductor material layer 104. In some embodiments, the first light-emitting element 10 is, for example, a vertical light-emitting diode. As shown in FIG. 1 , the first anode 100 and the first cathode 102 may be disposed on opposite sides of the first semiconductor material layer 104, respectively, but the relative arrangement relationship of the first anode 100, the first cathode 102 and the first semiconductor material layer 104 is not limited thereto.

The material of the first semiconductor material layer 104 may include a gallium nitride (GaN based) material or a gallium arsenide (GaAs based) material, but is not limited thereto. In some embodiments, the first semiconductor material layer 104 may include a light-emitting layer to emit the first color light L1. For example, if the first light-emitting element 10 is a red light-emitting element and the first color light L1 is red light, the material of the light-emitting layer may include a III-V material, such as gallium phosphide (GaP), gallium aluminum arsenide (AlGaAs), gallium arsenide phosphide (GaAsP) or aluminum gallium indium phosphide (AlGaInP), but is not limited thereto. In some embodiments, the light-emitting layer may be a multiple quantum well (MQW) layer, such as an alternating stack of multiple layers of indium nitride (InN) layers and multiple layers of gallium nitride (GaN) layers, but is not limited thereto.

In some embodiments, although not shown, the first semiconductor material layer 104 may also include one or more of an N-type doped layer, a P-type doped layer, an electron blocking layer, a barrier layer, a compliance layer, and other functional layers. It should be understood that the structure of the first semiconductor material layer 104 may adopt the structure of the semiconductor material layer in the known vertical red light-emitting diode, and no further restrictions are imposed here. In addition, the substrate for growing the first semiconductor material layer 104 may include any suitable substrate, and no further restrictions are imposed here.

The range of the first semiconductor material layer 104 covered by the first anode 100 or the first cathode 102 can be determined by the light transmittance of the electrode or the actual application (such as single-side light emission or double-side light emission). If the electrode located on the light-emitting side of the first semiconductor material layer 104 is made of a non-transparent conductive material, the electrode can expose part of the first semiconductor material layer 104 to reduce the shielding of the first color light L1. FIG. 1 schematically shows an implementation of single-side light emission, in which the first anode 100 is located on the light-emitting side of the first semiconductor material layer 104. If the first anode 100 is made of a non-transparent conductive material, the first anode 100 can expose part of the first semiconductor material layer 104, that is, the first anode 100 covers only part of the first semiconductor material layer 104 to reduce the shielding of the first color light L1. On the other hand, when the first anode 100 is made of a transparent conductive material, the first anode 100 can completely or partially cover the first semiconductor material layer 104. On the other hand, the light transmittance or coverage range of the first cathode 102 located on the non-light-emitting side of the first semiconductor material layer 104 can be not restricted.

The second light emitting element 12 is disposed on the light emitting side of the first light emitting element 10 and is suitable for allowing the first color light L1 to pass through. The second light emitting element 12 may include a second anode 120 and a second cathode 122, wherein the second cathode 122 is electrically connected to the first anode 100. For example, the second cathode 122 and the first anode 100 may be fused together by direct bonding, such as fusion bonding, but not limited thereto.

The second anode 120 and the second cathode 122 are made of conductive materials. The conductive material may include a transparent conductive material (such as metal oxide or graphene, etc.) or a non-transparent conductive material (such as metal or alloy, etc.). The top view shapes of the second anode 120 and the second cathode 122 are not limited. For example, the top view shapes of the second anode 120 and the second cathode 122 may be block-shaped, strip-shaped, sheet-shaped, frame-shaped, ring-shaped or irregular. In addition, the second anode 120 and the second cathode 122 may have the same or different top view shapes.

According to different requirements, the second light-emitting element 12 may also include other elements and/or film layers. For example, the second light-emitting element 12 may also include a second semiconductor material layer 124, and the second anode 120 and the second cathode 122 are disposed on the second semiconductor material layer 124. In some embodiments, the second light-emitting element 12 is, for example, a vertical light-emitting diode. As shown in FIG. 1 , the second anode 120 and the second cathode 122 may be disposed on opposite sides of the second semiconductor material layer 124, respectively, but the relative arrangement relationship of the second anode 120, the second cathode 122 and the second semiconductor material layer 124 is not limited thereto.

The second semiconductor material layer 124 may include two light-emitting layers, and the two light-emitting layers emit the second color light L2 and the third color light L3 respectively. For example, if the second light-emitting element 12 is a green-blue light-emitting element, the second color light L2 is green light, and the third color light L3 is blue light, the materials of the two light-emitting layers may include III-V materials, such as gallium phosphide (GaP), silicon carbide (SiC), cadmium zinc selenide (ZnCdSe) or gallium nitride, but not limited thereto. In some embodiments, the two light-emitting layers may be multiple quantum well layers, wherein the green light-emitting layer may be, for example, a plurality of layers of indium gallium nitride (such as In _0.25 Ga _0.75 N) and a plurality of layers of gallium nitride (GaN) alternately stacked layers, but not limited thereto; the blue light-emitting layer may be, for example, a plurality of layers of indium gallium nitride (such as In _0.15 Ga _0.85 N) and a plurality of layers of gallium nitride (GaN) alternately stacked layers, but not limited thereto.

In some embodiments, although not shown, the second semiconductor material layer 124 may also include one or more of an N-type doped layer, a P-type doped layer, an electron blocking layer, a barrier layer, a compliant layer, and other functional layers. It should be understood that the structure of the second semiconductor material layer 124 may adopt the structure of the semiconductor material layer in the known vertical green and blue light-emitting diodes, and no further restrictions are imposed here. In addition, the substrate for growing the second semiconductor material layer 124 may include any suitable substrate, and no further restrictions are imposed here.

The range of the second semiconductor material layer 124 covered by the second anode 120 or the second cathode 122 can be determined depending on the light transmittance of the electrode or the actual application (such as single-side light emission or double-side light emission). In this embodiment, the second light-emitting element 12 is arranged on the light-emitting side of the first light-emitting element 10. If the second cathode 122 is made of a non-transparent conductive material, the second cathode 122 can expose part of the second semiconductor material layer 124, that is, the second cathode 122 covers only part of the second semiconductor material layer 124, so as to reduce the shielding of the first color light L1. In addition, the second anode 120 can expose part of the second semiconductor material layer 124, that is, the second anode 120 covers only part of the second semiconductor material layer 124 to reduce the shielding of the first color light L1, the second color light L2 and/or the third color light L3. On the other hand, when the second anode 120 and the second cathode 122 are made of transparent conductive material, the second anode 120 and the second cathode 122 can completely cover or partially cover the second semiconductor material layer 124. Furthermore, when the second cathode 122 and the first anode 100 are fixed together by direct bonding, the second cathode 122 and the first anode 100 can have the same top view shape and area.

The operation method of the light-emitting device structure 1 may include the following steps: providing the light-emitting device structure 1; making the voltage difference between the first anode 100 and the first cathode 102 (such as voltage V2 minus voltage V1) greater than a first value, so that the first light-emitting element 10 emits a first color light L1; and making the voltage difference between the second anode 120 and the second cathode 122 (such as voltage V3 minus voltage V2) greater than a second value, so that the second light-emitting element 12 emits a second color light L2, wherein the second color light L2 and the first color light L1 are different colors.

In an embodiment where the first light-emitting element 10 is a monochromatic light-emitting element and the second light-emitting element 12 is a bichromatic light-emitting element, the operating method of the light-emitting device structure 1 may further include making the voltage difference between the second anode 120 and the second cathode 122 (such as voltage V3 minus voltage V2) greater than a third value, so that the second light-emitting element 12 emits a third color light L3, wherein the third value is different from the second value, and the third color light L3, the second color light L2 and the first color light L1 are different colors. For example, in an embodiment where the first light-emitting element 10 is a red light-emitting element 10 and the second light-emitting element 12 is a green-blue light-emitting element, the first color light L1 is red light, the second color light L2 is green light, and the third color light L3 is blue light.

Each of the first value to the third value may be different according to factors such as the selected materials and process parameters. For example, in an embodiment where the first semiconductor material layer 104 is made of a gallium arsenide-based material, the first value is, for example, 2 volts (volt, V), that is, when the voltage difference between the first anode 100 and the first cathode 102 is greater than 2 volts, the first light-emitting element 10 emits the first color light L1. On the other hand, in an embodiment where the first semiconductor material layer 104 is made of a gallium nitride-based material, the first value is, for example, 3 volts, that is, when the voltage difference between the first anode 100 and the first cathode 102 is greater than 3 volts, the first light-emitting element 10 emits the first color light L1. In addition, the second value is, for example, 3 volts, and the third value is, for example, 4 volts. That is, when the voltage difference between the second anode 120 and the second cathode 122 is greater than 3 volts, the second light-emitting element 12 emits the second color light L2, and when the voltage difference between the second anode 120 and the second cathode 122 is greater than 4 volts, the second light-emitting element 12 emits the third color light L3. It should be understood that the above-mentioned first to third values are only examples and are not intended to limit the present invention.

In some embodiments, the second cathode 122 and the first anode 100 can be grounded (i.e., the voltage V2 is 0). Under this structure, the voltage V1 can be -2 volts or -3 volts to light up the first light-emitting element 10 (so that the first light-emitting element 10 emits the first color light L1), and the voltage V3 can be 3 volts or 4 volts to light up the second light-emitting element 12 (so that the second light-emitting element 12 emits the second color light L2 or the third color light L3).

In other embodiments, the first cathode 102 can be grounded (i.e., the voltage V1 is 0). Under this structure, the voltage V2 can be 2 volts or 3 volts to light up the first light-emitting element 10 (e.g., to make the first light-emitting element 10 emit the first color light L1).

Compared to integrating three color light-emitting layers into the same light-emitting diode, by independently forming the first light-emitting element 10 and the second light-emitting element 12 and then stacking them together to form the light-emitting device structure 1, it is helpful to improve the brightness of the color light (such as red light), reduce the difficulty of the process or improve the yield. In addition, compared to setting the light-emitting diodes of multiple colors on the same plane, the light-emitting device structure 1 with a vertical stacking structure can occupy a smaller area, which helps to improve the resolution. In addition, by electrically connecting the second cathode 122 of the second light-emitting element 12 to the first anode 100 of the first light-emitting element 10, it helps to reduce the number of pins of the light-emitting device structure 1 and the number of corresponding external wires, thereby helping to improve the flexibility of circuit layout, simplify the process, reduce the space occupied by the circuit or improve the resolution.

Please refer to FIG. 2 , the main differences between the light-emitting device structure 1A and the light-emitting device structure 1 of FIG. 1 are described as follows. In the light-emitting device structure 1A, the monochromatic light-emitting element (such as the first light-emitting element 10 ) is, for example, a combination of a blue light-emitting element and a red wavelength conversion layer 106 .

Specifically, the first light-emitting element 10A includes a first anode 100, a first cathode 102, a first semiconductor material layer 104A, and a red wavelength conversion layer 106, wherein the blue light-emitting element is mainly composed of the first anode 100, the first cathode 102, and the first semiconductor material layer 104A, and the first semiconductor material layer 104A includes a blue light-emitting layer to output blue light B.

The blue light B is converted into the first color light L1 by the red wavelength conversion layer 106. The first semiconductor material layer 104A can adopt the structure of the semiconductor material layer in the known vertical blue light-emitting diode, and no limitation is imposed here. The material of the red wavelength conversion layer 106 may include red quantum dots, red phosphors, rare earth materials or other red materials. In addition, the red wavelength conversion layer 106 may be in the form of particles, gel, film or plate.

In the structure where the first light-emitting element 10A is a combination of a blue light-emitting element and a red wavelength conversion layer, and the second light-emitting element 12 is a green-blue light-emitting element, the first value and the third value may be the same (for example, both are 4 volts). Specifically, the voltage difference between the first anode 100 and the first cathode 102 (such as voltage V2 minus voltage V1) may be greater than 4 volts, so that the first semiconductor material layer 104A emits blue light B, and the blue light B is converted into the first color light L1 by the red wavelength conversion layer 106 and output from the first light-emitting element 10A. In the structure where the second cathode 122 and the first anode 100 are grounded, the voltage V1 is, for example, -4 volts. In the structure where the first cathode 102 is grounded, the voltage V2 is, for example, 4 volts.

In some embodiments, although not shown in FIG. 2 , the first light emitting element 10A may be a green or blue light emitting element, and the first light emitting element 10A may emit blue light B by modulating the voltage difference, and then the blue light B is converted into the first color light L1 by the red wavelength conversion layer 106 .

Referring to FIG. 3 , the main differences between the light-emitting device structure 1B and the light-emitting device structure 1 of FIG. 1 are described as follows. The light-emitting device structure 1B further includes a third light-emitting element 14. The third light-emitting element 14 is stacked on the second light-emitting element 12 and is suitable for allowing the first color light L1 and the second color light L2 to pass through. The third light-emitting element 14 includes a third anode 140 and a third cathode 142, wherein the third cathode 142 is electrically connected to the second anode 120. For example, in the case where the third light-emitting element 14 is a vertical light-emitting diode, the third cathode 142 and the second anode 120 can be fused together by melt bonding, but the present invention is not limited thereto.

The first light-emitting element 10, the second light-emitting element 12B and the third light-emitting element 14 can all be single-color light-emitting elements. For example, the first light-emitting element 10 is a red light-emitting element, the second light-emitting element 12B is a green light-emitting element, and the third light-emitting element 14 is a blue light-emitting element, but not limited thereto. The first semiconductor material layer 104 in the first light-emitting element 10 includes a red light-emitting layer to output red light (first color light L1), the second semiconductor material layer 124B in the second light-emitting element 12B includes a green light-emitting layer to output green light (second color light L2), and the third semiconductor material layer 144 in the third light-emitting element 14 includes a blue light-emitting layer to output blue light (third color light L3).

In some embodiments, although not shown, the first semiconductor material layer 104, the second semiconductor material layer 124B, and the third semiconductor material layer 144 may each further include one or more of an N-type doped layer, a P-type doped layer, an electron blocking layer, a barrier layer, a compliant layer, and other functional layers. It should be understood that the structures of the first semiconductor material layer 104, the second semiconductor material layer 124B, and the third semiconductor material layer 144 may respectively adopt the structures of semiconductor material layers in known vertical red light-emitting diodes, vertical green light-emitting diodes, and vertical blue light-emitting diodes, without further limitation. In addition, the substrate for growing the first semiconductor material layer 104, the second semiconductor material layer 124B, and the third semiconductor material layer 144 may include any suitable substrate, without limitation.

By independently forming three color LEDs and then stacking the three color LEDs together, the voltage difference (e.g., voltage V2 minus voltage V1) between the first anode 100 and the first cathode 102 can be greater than a first value (e.g., 2 volts or 3 volts), so that the first light emitting element 10 emits the first color light L1; the second anode 120 and the second cathode 12 2 (e.g., voltage V3 minus voltage V2) is greater than a second value (e.g., 3 volts) so that the second light-emitting element 12B emits a second color light L2; and the voltage difference between the third anode 140 and the third cathode 142 (e.g., voltage V4 minus voltage V3) is greater than a third value (e.g., 4 volts) so that the third light-emitting element 14 emits a third color light L3. The first value and the third value may be different, and the second value and the third value may be different, but are not limited thereto.

Compared to integrating three color light-emitting layers into the same light-emitting diode, by independently forming light-emitting elements of different colors (such as the first light-emitting element 10, the second light-emitting element 12B and the third light-emitting element 14), and then stacking the light-emitting elements of different colors together to form the light-emitting device structure 1B, it is helpful to improve the brightness of each color light, reduce the difficulty of the process or improve the yield. In addition, compared to setting the light-emitting diodes of multiple colors on the same plane, the light-emitting device structure 1B with a vertical stacking structure can occupy a smaller area, which helps to improve the resolution. In addition, by connecting light-emitting elements of different colors in series, it helps to reduce the number of pins of the light-emitting device structure 1B and the number of corresponding external wires, which helps to improve the flexibility of circuit layout, simplify the process, reduce the space occupied by the circuit or improve the resolution.

Please refer to FIG. 4 , the main difference between the light-emitting device structure 1C and the light-emitting device structure 1B of FIG. 3 is described as follows. In the light-emitting device structure 1C, the first light-emitting element 10A is a combination of a blue light-emitting element and a red wavelength conversion layer, and the second light-emitting element 12C is a combination of a blue light-emitting element and a green wavelength conversion layer.

Specifically, the first light-emitting element 10A includes a first anode 100, a first cathode 102, a first semiconductor material layer 104A, and a red wavelength conversion layer 106, wherein the blue light-emitting element is mainly composed of the first anode 100, the first cathode 102, and the first semiconductor material layer 104A, and the first semiconductor material layer 104A includes a blue light-emitting layer to output blue light B. The blue light B is converted into the first color light L1 by the red wavelength conversion layer 106.

The second light-emitting element 12C includes a second anode 120, a second cathode 122, a second semiconductor material layer 124C and a green wavelength conversion layer 126, wherein the blue light-emitting element is mainly composed of the second anode 120, the second cathode 122 and the second semiconductor material layer 124C, and the second semiconductor material layer 124C includes a blue light-emitting layer to output blue light B. The blue light B is converted into a second color light L2 by the green wavelength conversion layer 126. The first semiconductor material layer 104A and the second semiconductor material layer 124C can adopt the structure of the semiconductor material layer in the known vertical blue light-emitting diode, and no limitation is imposed here.

The material of the red wavelength conversion layer 106 may include red quantum dots, red phosphors, rare earth materials or other red materials. In addition, the red wavelength conversion layer 106 may be in the form of particles, gels, films or plates. The material of the green wavelength conversion layer 126 may include green quantum dots, green phosphors, rare earth materials or other green materials. In addition, the green wavelength conversion layer 126 may be in the form of particles, gels, films or plates.

In the case where the first light-emitting element 10A is a combination of a blue light-emitting element and a red wavelength conversion layer, the second light-emitting element 12C is a combination of a blue light-emitting element and a green wavelength conversion layer, and the third light-emitting element 14 is a blue light-emitting element, the first value, the second value, and the third value may be the same (e.g., all 4 volts). Specifically, the voltage difference between the first anode 100 and the first cathode 102 (e.g., voltage V2 minus voltage V1) may be greater than 4 volts, so that the first semiconductor material layer 104A emits blue light B, and the blue light B is converted into the first color light L1 by the red wavelength conversion layer 106 and output from the first light-emitting element 10A. The voltage difference between the second anode 120 and the second cathode 122 (such as voltage V3 minus voltage V2) can be greater than 4 volts, so that the second semiconductor material layer 124C emits blue light B, and the blue light B is converted into the second color light L2 by the green wavelength conversion layer 126 and output from the second light-emitting element 12C. The voltage difference between the third anode 140 and the third cathode 142 (such as voltage V4 minus voltage V3) can be greater than 4 volts, so that the third semiconductor material layer 144 emits the third color light L3.

Referring to FIG. 5 , the main difference between the light emitting device structure 1D and the light emitting device structure 1 of FIG. 1 is that the first light emitting element 10D and the second light emitting element 12D in the light emitting device structure 1D are both lateral light emitting diodes, wherein the first anode 100 and the first cathode 102 are disposed on the same side (such as the light emitting side) of the first semiconductor material layer 104D, and the second anode 120 and the second cathode 122 are disposed on the same side (such as the light emitting side) of the second semiconductor material layer 124D.

The first semiconductor material layer 104D may include a platform portion 104-1 and a protrusion 104-2. Although not shown in FIG. 5 , the platform portion 104-1 may include a substrate, a buffer layer, and an N-type doped layer, but is not limited thereto. The buffer layer and the N-type doped layer are sequentially stacked on the substrate. The protrusion 104-2 and the first cathode 102 are disposed on the N-type doped layer of the platform portion 104-1 and are separated from each other. The protrusion 104-2 may include a compliant layer, a light-emitting layer (such as a red light-emitting layer), an electron blocking layer, and a P-type doped layer sequentially stacked on the platform portion 104-1, but is not limited thereto. The first anode 100 is disposed on the protrusion 104-2.

The second semiconductor material layer 124D may include a platform portion 124-1 and a protrusion portion 124-2. Although not shown in FIG. 5 , the platform portion 124-1 may include a substrate, a buffer layer, and an N-type doped layer, but is not limited thereto. The buffer layer and the N-type doped layer are sequentially stacked on the substrate. The protrusion portion 124-2 and the second cathode 122 are disposed on the N-type doped layer of the platform portion 124-1 and are separated from each other. The protrusion 124-2 may include a compliant layer, a blue light-emitting layer (or a green light-emitting layer), a barrier layer, a green light-emitting layer (or a blue light-emitting layer), an electron blocking layer, and a P-type doped layer sequentially stacked on the platform 124-1, but is not limited thereto. The second anode 120 is disposed on the protrusion 124-2.

It should be understood that the number of film layers and/or stacking order in the first semiconductor material layer 104D or the second semiconductor material layer 124D can be changed according to actual needs and is not limited to the above examples.

In the structure where both the first light-emitting element 10D and the second light-emitting element 12D are horizontal light-emitting diodes, the second light-emitting element 12D can be fixed to the first light-emitting element 10D through a transparent adhesive layer (not shown) or other fixing elements (not shown). In addition, the second cathode 122 and the first anode 100 can be electrically connected through a wire W. FIG. 5 schematically shows the wire W used to electrically connect the second cathode 122 and the first anode 100, but the actual arrangement of the wire W can be changed according to actual needs.

FIG6 schematically illustrates one arrangement of the wire W. Please refer to FIG6. In some embodiments, the top view area of the first semiconductor material layer 104D may be larger than the top view area of the second semiconductor material layer 124D. The wire W may be arranged on the first semiconductor material layer 104D and the second semiconductor material layer 124D and electrically insulated from the first cathode 102 and the second anode 120.

For example, the top-view area of the platform portion 104-1 of the first semiconductor material layer 104D may be larger than the top-view area of the protrusion 104-2 of the first semiconductor material layer 104D, the top-view area of the protrusion 104-2 of the first semiconductor material layer 104D may be larger than the top-view area of the platform portion 124-1 of the second semiconductor material layer 124D, and the top-view area of the platform portion 124-1 of the second semiconductor material layer 124D may be larger than the top-view area of the protrusion 124-2 of the second semiconductor material layer 124D. The wire W can be disposed on the platform portion 124-1 of the second semiconductor material layer 124D and the protrusion 104-2 of the first semiconductor material layer 104D and electrically connect the second cathode 122 to the first anode 100.

Through the aforementioned voltage difference control (please refer to the operation method of the light-emitting device structure 1 in FIG1 ), the light-emitting region R of the light-emitting device structure 1D can also perform full-color display (for example, it can output red light, green light and/or blue light). The effect of the light-emitting device structure 1D can refer to the effect of the light-emitting device structure 1 in FIG1 , and will not be repeated here.

Referring to FIG. 7 , the main difference between the light-emitting device structure 1E and the light-emitting device structure 1A of FIG. 2 is that the first light-emitting element 10E and the second light-emitting element 12D in the light-emitting device structure 1E are both horizontal light-emitting diodes, wherein the first anode 100 and the first cathode 102 are disposed on the same side (such as the light-emitting side) of the first semiconductor material layer 104E, and the second anode 120 and the second cathode 122 are disposed on the same side (such as the light-emitting side) of the second semiconductor material layer 124D.

The main difference between the first light-emitting element 10E and the first light-emitting element 10D in FIG5 is that the first light-emitting element 10E is a combination of a blue light-emitting element (including a first anode 100, a first cathode 102, and a first semiconductor material layer 104E) and a red wavelength conversion layer 106. The first semiconductor material layer 104E includes a platform portion 104-1 and a protrusion 104-2'. Although not shown in FIG7, the platform portion 104-1 may include a substrate, a buffer layer, and an N-type doped layer, but is not limited thereto. The buffer layer and the N-type doped layer are sequentially stacked on the substrate. The protrusion 104-2' and the first cathode 102 are disposed on the N-type doped layer of the platform 104-1 and are separated from each other. The protrusion 104-2' may include a compliant layer, a luminescent layer (such as a blue luminescent layer), an electron blocking layer, and a P-type doped layer stacked in sequence on the platform 104-1, but is not limited thereto. The first anode 100 is disposed on the protrusion 104-2'. The blue light B output by the blue luminescent layer is converted into the first color light L1 by the red wavelength conversion layer 106 and then output from the first light-emitting element 10E.

The operation method of the light-emitting device structure 1E can refer to the operation method of the light-emitting device structure 1A in Figure 2, and will not be repeated here.

In some embodiments, although not shown in FIG. 7 , the first light-emitting element 10E may be a green or blue light-emitting element (for example, the first semiconductor material layer 104E is replaced by the second semiconductor material layer 124D), and the first light-emitting element 10E may emit blue light B by modulating the voltage difference, and then the blue light B is converted into the first color light L1 by the red wavelength conversion layer 106 .

Referring to FIG. 8 , the main difference between the light-emitting device structure 1F and the light-emitting device structure 1B of FIG. 3 is that the first light-emitting element 10D, the second light-emitting element 12F and the third light-emitting element 14F in the light-emitting device structure 1E are all horizontal light-emitting diodes, wherein the first anode 100 and the first cathode 102 are arranged on the same side (such as the light-emitting side) of the first semiconductor material layer 104D, the second anode 120 and the second cathode 122 are arranged on the same side (such as the light-emitting side) of the second semiconductor material layer 124F, and the third anode 140 and the third cathode 142 are arranged on the same side (such as the light-emitting side) of the third semiconductor material layer 144F.

The second semiconductor material layer 124F may include a platform portion 124-1 and a protrusion 124-2'. Although not shown in FIG. 8, the platform portion 124-1 may include a substrate, a buffer layer, and an N-type doped layer, but is not limited thereto. The buffer layer and the N-type doped layer are sequentially stacked on the substrate. The protrusion 124-2' and the second cathode 122 are disposed on the N-type doped layer of the platform portion 124-1 and are separated from each other. The protrusion 124-2' may include a compliant layer, a green light-emitting layer, an electron blocking layer, and a P-type doped layer sequentially stacked on the platform portion 124-1, but is not limited thereto. The second anode 120 is disposed on the protrusion 124-2'.

The third semiconductor material layer 144F may include a platform portion 144-1 and a protrusion 144-2. Although not shown in FIG. 8 , the platform portion 144-1 may include a substrate, a buffer layer, and an N-type doped layer, but is not limited thereto. The buffer layer and the N-type doped layer are sequentially stacked on the substrate. The protrusion 144-2 and the third cathode 142 are disposed on the N-type doped layer of the platform portion 144-1 and are separated from each other. The protrusion 144-2 may include a compliant layer, a blue light-emitting layer, an electron blocking layer, and a P-type doped layer sequentially stacked on the platform portion 144-1, but is not limited thereto. The third anode 140 is disposed on the protrusion 144-2.

The operation method of the light-emitting device structure 1F can refer to the operation method of the light-emitting device structure 1B in FIG. 3 , and will not be repeated here.

In the case where the first light-emitting element 10D, the second light-emitting element 12F and the third light-emitting element 14F are all horizontal light-emitting diodes, the second light-emitting element 12F can be fixed to the first light-emitting element 10D through a transparent adhesive layer (not shown) or other fixing elements (not shown), and the third light-emitting element 14F can be fixed to the second light-emitting element 12F through a transparent adhesive layer (not shown) or other fixing elements (not shown). In addition, the second cathode 122 and the first anode 100 can be electrically connected through a wire W, and the third cathode 142 and the second anode 120 can be electrically connected through a wire W'. FIG8 schematically shows the wire W for electrically connecting the second cathode 122 to the first anode 100 and the wire W' for electrically connecting the third cathode 142 to the second anode 120, but the actual arrangement of the wire W and the wire W' can be changed according to actual needs.

FIG9 schematically illustrates one arrangement of the wire W and the wire W'. Referring to FIG9, in some embodiments, the top view area of the first semiconductor material layer 104D may be larger than the top view area of the second semiconductor material layer 124F, and the top view area of the second semiconductor material layer 124F may be larger than the top view area of the third semiconductor material layer 144F. In addition, the wire W may be arranged on the first semiconductor material layer 104D and the second semiconductor material layer 124F and be electrically insulated from the first cathode 102 and the second anode 120. The wire W' can be disposed in the second semiconductor material layer 124F and the third semiconductor material layer 144F and is electrically insulated from the second cathode 122 and the third anode 140.

For example, the top view area of the terrace portion 104-1 of the first semiconductor material layer 104D may be larger than the top view area of the protrusion 104-2 of the first semiconductor material layer 104D, the top view area of the protrusion 104-2 of the first semiconductor material layer 104D may be larger than the top view area of the terrace portion 124-1 of the second semiconductor material layer 124F, and the top view area of the terrace portion 124-1 of the second semiconductor material layer 124F may be larger than the top view area of the terrace portion 124-1 of the second semiconductor material layer 124F. The top-view area of the protrusion 124-2' of the second semiconductor material layer 124F may be larger than the top-view area of the platform portion 144-1 of the third semiconductor material layer 144F, and the top-view area of the platform portion 144-1 of the third semiconductor material layer 144F may be larger than the top-view area of the protrusion 144-2 of the third semiconductor material layer 144F. The wire W can be disposed on the platform portion 124-1 of the second semiconductor material layer 124F and the protrusion 104-2 of the first semiconductor material layer 104D and electrically connect the second cathode 122 to the first anode 100, and the wire W' can be disposed on the platform portion 144-1 of the third semiconductor material layer 144F and the protrusion 124-2' of the second semiconductor material layer 124F and electrically connect the third cathode 142 to the second anode 120.

Through the aforementioned voltage difference control (please refer to the operation method of the light-emitting device structure 1B in FIG3 ), the light-emitting region R of the light-emitting device structure 1F can also perform full-color display (for example, it can output red light, green light and/or blue light). The effect of the light-emitting device structure 1F can refer to the effect of the light-emitting device structure 1B in FIG3 , and will not be repeated here.

Referring to FIG. 10 , the main difference between the light emitting device structure 1G and the light emitting device structure 1C of FIG. 4 is that the first light emitting element 10E, the second light emitting element 12G and the third light emitting element 14F in the light emitting device structure 1G are all horizontal light emitting diodes, wherein the first anode 100 and the first cathode 102 are arranged on the same side (such as the light emitting side) of the first semiconductor material layer 104E, the second anode 120 and the second cathode 122 are arranged on the same side (such as the light emitting side) of the second semiconductor material layer 124G, and the third anode 140 and the third cathode 142 are arranged on the same side (such as the light emitting side) of the third semiconductor material layer 144F.

The details of the first light-emitting element 10E can refer to the description of the first light-emitting element 10E in FIG. 7 , which will not be repeated here. In addition, the details of the third light-emitting element 14F can refer to the description of the third light-emitting element 14F in FIG. 8 , which will not be repeated here. The main difference between the second light-emitting element 12G and the second light-emitting element 12F in FIG. 8 is that the second light-emitting element 12G is a combination of a blue light-emitting element (including a second anode 120, a second cathode 122, and a second semiconductor material layer 124G) and a green wavelength conversion layer 126.

The second semiconductor material layer 124G may include a platform portion 124-1 and a protrusion 124-2". Although not shown in FIG. 10, the platform portion 124-1 may include a substrate, a buffer layer and an N-type doped layer, but is not limited thereto. The buffer layer and the N-type doped layer are sequentially stacked on the substrate. The protrusion 124-2" and the second cathode 122 are disposed on the N-type doped layer of the platform portion 124-1 and are separated from each other. The protrusion 124-2" may include a compliant layer, a blue light-emitting layer, an electron blocking layer, and a P-type doped layer stacked sequentially on the platform 124-1, but is not limited thereto. The second anode 120 is disposed on the protrusion 124-2". The blue light B emitted by the blue light-emitting layer is converted into the second color light L2 by the green wavelength conversion layer 126.

The operation method of the light-emitting device structure 1G can refer to the operation method of the light-emitting device structure 1C in FIG. 4 , and will not be repeated here.

In summary, in the embodiment of the present invention, by independently forming light-emitting elements of different colors and then stacking the light-emitting elements of different colors together to form a light-emitting device structure, it is helpful to improve the brightness of each color of light, reduce the difficulty of the process or improve the yield. In addition, the light-emitting device structure using a vertical stacking structure can occupy a smaller area, which helps to improve the resolution. In addition, by connecting light-emitting elements of different colors in series, it helps to reduce the number of pins of the light-emitting device structure and the number of corresponding external wires, which helps to improve the flexibility of circuit layout, simplify the process, reduce the space occupied by the circuit or improve the resolution.

Although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of the attached patent application.

1, 1A, 1C, 1D, 1E, 1F, 1G: Light-emitting device structure

10, 10A, 10D, 10E: first light-emitting element

12, 12B, 12C, 12D, 12F, 12G: Second light-emitting element

14, 14F: The third light-emitting element

100: The First Anode

102: First cathode

104, 104A, 104D, 104E: first semiconductor material layer

104-1, 124-1, 144-1: Platform Department

104-2, 104-2’, 124-2, 124-2’, 124-2”, 144-2: protrusions

106: Red wavelength conversion layer

120: Second Anode

122: Second cathode

124, 124B, 124C, 124D, 124F, 124G: second semiconductor material layer

126: Green wavelength conversion layer

140: The third anode

142: The third cathode

144, 144F: Third semiconductor material layer

B: Blue light

L1: First color light

L2: Second color light

L3: The third color light

R: Luminous area

V1, V2, V3, V4: voltage

W, W’: conductor

Figures 1 to 5, Figure 7, Figure 8 and Figure 10 are schematic diagrams of light-emitting device structures according to multiple embodiments of the present disclosure.

Figure 6 is a schematic top view of the light-emitting device structure of Figure 5.

FIG9 is a schematic top view of the light-emitting device structure of FIG8 .

1: Light-emitting device structure 10: First light-emitting element 12: Second light-emitting element 100: First anode 102: First cathode 104: First semiconductor material layer 120: Second anode 122: Second cathode 124: Second semiconductor material layer L1: First color light L2: Second color light L3: Third color light V1, V2, V3: Voltage

Claims (11)

A light-emitting device structure includes: a first light-emitting element including a first anode and a first cathode; and a second light-emitting element stacked on the first light-emitting element and including a second anode and a second cathode, wherein the second cathode is electrically connected to the first anode, and wherein: the first light-emitting element is a single-color light-emitting element, and the second light-emitting element is a two-color light-emitting element, the first cathode is electrically connected to a first signal source, the second cathode and the first anode are electrically connected to a second signal source, the second anode is electrically connected to a third signal source, and the first signal source, the second signal source and the third signal source are electrically independent of each other. A light-emitting device structure as described in claim 1, wherein the monochromatic light-emitting element is a red light-emitting element, and the bichromatic light-emitting element is a green-blue light-emitting element. A light-emitting device structure as described in claim 1, wherein the monochromatic light-emitting element is a combination of a blue light-emitting element and a red wavelength conversion layer, and the dual-color light-emitting element is a green-blue light-emitting element. The light-emitting device structure as described in claim 1, wherein the first light-emitting element further includes a first semiconductor material layer, and the first anode and the first cathode are respectively arranged on opposite sides of the first semiconductor material layer, and wherein the second light-emitting element further includes a second semiconductor material layer, and the second anode and the second cathode are respectively arranged on opposite sides of the second semiconductor material layer. A light-emitting device structure as described in claim 4, wherein the second cathode is fused with the first anode. A light-emitting device structure as described in claim 1, wherein the first light-emitting element further includes a first semiconductor material layer, and the first anode and the first cathode are arranged on the same side of the first semiconductor material layer, and wherein the second light-emitting element further includes a second semiconductor material layer, and the second anode and the second cathode are arranged on the same side of the second semiconductor material layer. A light-emitting device structure as described in claim 6, wherein the second cathode is electrically connected to the first anode via a wire, and the wire is disposed on the first semiconductor material layer and the second semiconductor material layer and is electrically insulated from the first cathode and the second anode. A light-emitting device structure as described in claim 6, wherein the top-view area of the first semiconductor material layer is larger than the top-view area of the second semiconductor material layer. A method for operating a light-emitting device structure comprises: providing the light-emitting device structure, the light-emitting device structure comprising: a first light-emitting element, comprising a first anode and a first cathode; and a second light-emitting element, stacked on the first light-emitting element and comprising a second anode and a second cathode, wherein the second cathode is electrically connected to the first anode, and wherein: the first light-emitting element is a single-color light-emitting element, and the second light-emitting element is a two-color light-emitting element, the first cathode is electrically connected to a first signal source, the second cathode and the first anode are electrically connected to a second signal source, the second anode is electrically connected to a third signal source, and the first signal source, the second signal source and The third signal sources are electrically independent of each other; through the second signal source and the first signal source, the voltage difference between the first anode and the first cathode is greater than a first value, so that the first light-emitting element emits a first color light; through the third signal source and the second signal source, the voltage difference between the second anode and the second cathode is greater than a second value, so that the second light-emitting element emits a second color light; and through the third signal source and the second signal source, the voltage difference between the second anode and the second cathode is greater than a third value, so that the second light-emitting element emits a third color light, wherein the third color light, the second color light and the first color light are different colors. The method for operating a light-emitting device structure as described in claim 9, wherein the first light-emitting element is a red light-emitting element, and the first value is different from the third value. The operating method of the light-emitting device structure as described in claim 9, wherein the first light-emitting element is a combination of a blue light-emitting element and a red wavelength conversion layer, and the first value is the same as the third value.

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