TWI859601B - Light-emitting element, manufacturing method thereof and display device comprising the same - Google Patents

Abstract

A light-emitting element includes a first semiconductor pattern, a second semiconductor pattern, a light-emitting pattern, a first electrode and a second electrode. The first semiconductor pattern has a first side, a second side, a third and a fourth side, wherein the first side is opposite to the second side, the third side is opposite to the fourth side, and the third side and the fourth side connect the first side to the second side individually. The second semiconductor pattern is disposed at the second side of the first semiconductor pattern, and a length of the second semiconductor pattern is longer than a length of the first semiconductor pattern. The light-emitting pattern is disposed between first semiconductor pattern and the second semiconductor pattern. The first electrode is disposed at one side of the second semiconductor pattern away from the first semiconductor pattern and electrically connected to the second semiconductor pattern. The second electrode is disposed at the third side and the fourth side of the first semiconductor pattern and electrically connected to the first semiconductor pattern. A manufacturing method of the light-emitting element and a display device comprising the light-emitting element are also provided.

Description

Light-emitting element, manufacturing method thereof and display device including the same

The present invention relates to a light-emitting element, a manufacturing method of the light-emitting element and a display device including the light-emitting element.

Micro-LED display devices have the advantages of power saving, high efficiency, high brightness and fast response time. Generally speaking, micro-LEDs can be divided into horizontal (Lateral) and vertical (Vertical) micro-LEDs according to whether their two electrodes are on the same side or different sides of the light-emitting layer. Among them, vertical micro-LEDs are expected to become the mainstream structure in the future due to their better heat dissipation and light-emitting efficiency.

Since vertical micro-LEDs are relatively tall, after mass transfer to the circuit substrate, multiple (at least three) flat layers are required to fill the topographical differences to facilitate electrode bridging. However, the flatness of multiple flat layers is difficult to control, resulting in poor electrode bridging yield, which affects the production yield of display devices.

The present invention provides a light-emitting element having a structure that facilitates electrode bridging.

The present invention provides a method for manufacturing a light-emitting element, which can produce a light-emitting element having a structure that is convenient for electrode bridging.

The present invention provides a display device with improved production yield.

An embodiment of the present invention provides a light-emitting element, comprising: a first semiconductor pattern having a first side, a second side, a third side and a fourth side, wherein the first side is opposite to the second side, the third side is opposite to the fourth side, and the third side and the fourth side are connected to the first side and the second side; a second semiconductor pattern located on the second side of the first semiconductor pattern, and the length of the second semiconductor pattern is greater than the length of the first semiconductor pattern; a light-emitting pattern located between the first semiconductor pattern and the second semiconductor pattern; a first electrode located on a side of the second semiconductor pattern far from the first semiconductor pattern and electrically connected to the second semiconductor pattern; and a second electrode located on the third side and the fourth side of the first semiconductor pattern and electrically connected to the first semiconductor pattern.

In one embodiment of the present invention, the second electrode surrounds the first semiconductor pattern.

In one embodiment of the present invention, the second electrode physically contacts the third side and the fourth side of the first semiconductor pattern.

In one embodiment of the present invention, the first electrode comprises a high reflectivity conductive material.

In one embodiment of the present invention, the length of the first electrode is 20% to 90% of the length of the second semiconductor pattern.

In one embodiment of the present invention, the second electrode is also located on the first side of the first semiconductor pattern.

In one embodiment of the present invention, the second electrode has a first opening, and the first opening exposes the first semiconductor pattern.

In one embodiment of the present invention, the light emitting element further includes a first transparent conductive pattern located between the first electrode and the second semiconductor pattern.

An embodiment of the present invention provides a display device, including: a circuit substrate; and a plurality of the above-mentioned light-emitting elements, which are arranged on the circuit substrate and electrically connected to the circuit substrate.

In an embodiment of the present invention, the display device further includes a first pad and a second pad, wherein the first electrode is electrically connected to the first pad, and the second electrode is electrically connected to the second pad through the second transparent conductive layer.

In an embodiment of the present invention, the display device further includes a protective layer covering the plurality of light-emitting elements and the second transparent conductive layer.

An embodiment of the present invention provides a method for manufacturing a light-emitting element, including: forming a first semiconductor layer on a growth substrate, and a first side of the first semiconductor layer is close to the growth substrate; forming a light-emitting layer on a second side of the first semiconductor layer, and the second side is opposite to the first side; forming a second semiconductor layer on the light-emitting layer; forming a first electrode on the second semiconductor layer; removing the growth substrate; patterning the first semiconductor layer, the light-emitting layer and the second semiconductor layer to form a first semiconductor pattern, a light-emitting pattern and a second semiconductor pattern respectively, and the length of the second semiconductor pattern is greater than the length of the first semiconductor pattern; and forming a second electrode on a third side and a fourth side of the first semiconductor pattern, and the third side and the fourth side are respectively connected to the first side and the second side.

In one embodiment of the present invention, the manufacturing method of the light emitting element further includes forming a buffer layer on the growth substrate before forming the first semiconductor layer.

In one embodiment of the present invention, the manufacturing method of the light emitting element further includes removing the buffer layer after removing the growth substrate.

In an embodiment of the present invention, the manufacturing method of the light-emitting element further includes forming a first transparent conductive layer on the second semiconductor layer after forming the second semiconductor layer.

In an embodiment of the present invention, the manufacturing method of the light-emitting element further includes performing an annealing process on the first transparent conductive layer.

In an embodiment of the present invention, the manufacturing method of the light-emitting element further includes patterning the first transparent conductive layer after patterning the first semiconductor layer, the light-emitting layer and the second semiconductor layer to form a first transparent conductive pattern.

In an embodiment of the present invention, the manufacturing method of the light emitting element further includes forming a first insulating layer having a second opening on the second semiconductor layer before forming the first electrode, and the first electrode is formed in the second opening.

In one embodiment of the present invention, the manufacturing method of the light emitting element further includes forming a second insulating pattern on the sidewalls of the light emitting pattern and the second semiconductor pattern before forming the second electrode.

In an embodiment of the present invention, the manufacturing method of the light emitting element further includes forming a second electrode on a first side of the first semiconductor pattern, and the second electrode does not completely cover the first semiconductor pattern.

In order to make the above features and advantages of the present invention more clearly understood, embodiments are specifically cited below and described in detail with reference to the accompanying drawings.

In the accompanying drawings, for the sake of clarity, the thickness of layers, films, panels, regions, etc. is magnified. Throughout the specification, the same figure markings represent the same elements. It should be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to another element, or an intermediate element can also exist. On the contrary, when an element is referred to as being "directly on" or "directly connected to" another element, there is no intermediate element. As used herein, "connection" can refer to physical and/or electrical connection. Furthermore, "electrical connection" or "coupling" can be the presence of other elements between two elements.

It should be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and/or portions, these elements, components, regions, layers and/or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or portion from another element, component, region, layer or portion. Therefore, the first "element", "component", "region", "layer" or "portion" discussed below can be referred to as a second element, component, region, layer or portion without departing from the teachings of this article.

The terms used herein are for the purpose of describing specific embodiments only and are not restrictive. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms, including "at least one" or to mean "and/or". As used herein, the term "and/or" includes any and all combinations of one or more of the relevant listed items. It should also be understood that when used in this specification, the terms "include" and/or "include" specify the presence of the features, regions, wholes, steps, operations, elements and/or parts, but do not exclude the presence or addition of one or more other features, regions, wholes, steps, operations, elements, parts and/or combinations thereof.

In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one figure is flipped, the elements described as being on the "lower" side of the other elements will be oriented on the "upper" side of the other elements. Therefore, the exemplary term "lower" can include both "lower" and "upper" orientations, depending on the specific orientation of the figure. Similarly, if the device in one figure is flipped, the elements described as being "lower" or "below" other elements will be oriented as being "above" other elements. Therefore, the exemplary term "lower" or "below" can include both above and below orientations.

As used herein, "about," "approximately," or "substantially" includes the stated value and the average value within an acceptable deviation range of the particular value determined by a person of ordinary skill in the art, taking into account the measurement in question and the particular amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within ±30%, ±20%, ±10%, ±5%. Furthermore, as used herein, "about," "approximately," or "substantially" can select a more acceptable deviation range or standard deviation depending on the optical property, etching property, or other property, and can apply to all properties without a single standard deviation.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by ordinary technicians in the field to which the present invention belongs. It will be further understood that those terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and the present invention, and will not be interpreted as an idealized or overly formal meaning unless expressly defined as such in this document.

Exemplary embodiments are described herein with reference to cross-sectional views that are schematic illustrations of idealized embodiments. Therefore, variations in the shapes of the illustrations as a result of, for example, manufacturing techniques and/or tolerances are to be expected. Therefore, the embodiments described herein should not be construed as limited to the specific shapes of the regions as shown herein, but rather include shape deviations that result, for example, from manufacturing. For example, a region shown or described as flat may typically have rough and/or nonlinear features. Furthermore, sharp corners shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the exact shape of the regions and are not intended to limit the scope of the claims.

1A to 1I(b) are partial cross-sectional schematic diagrams and partial top view schematic diagrams of the steps of a manufacturing method of a light-emitting element 10 according to an embodiment of the present invention. The manufacturing method of the light-emitting element 10 is described below with reference to FIG. 1A to FIG. 1I(b).

First, referring to FIG. 1A , a first semiconductor layer 130′ is formed on a growth substrate 110, and a first side S1 of the first semiconductor layer 130′ is close to the growth substrate 110. The growth substrate 110 may be a growth substrate for growing epitaxial materials, such as a sapphire substrate, but the present invention is not limited thereto.

In some embodiments, the first semiconductor layer 130' is grown on the growth substrate 110 by epitaxial growth, and its main material includes gallium nitride (GaN), but the present invention is not limited thereto. For example, the first semiconductor layer 130' is an N-type doped semiconductor layer, and the material of the N-type doped semiconductor layer is, for example, N-type gallium nitride (n-GaN) that needs to be formed using an ultra-high temperature process. In other embodiments, the first semiconductor layer 130' may include a II-VI Group material (e.g., zinc selenide (ZnSe)) or a III-V Group nitride material (e.g., gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), or aluminum indium gallium nitride (AlInGaN)).

In some embodiments, a buffer layer 120 may be formed on the growth substrate 110 before forming the first semiconductor layer 130'. The buffer layer 120 can help release stress of the semiconductor layer to be subsequently epitaxially grown, and reduce epitaxial dislocation and defects, so as to adjust the material properties of the first semiconductor layer 130', such as lattice constant, carrier transfer efficiency, etc. For example, the buffer layer 120 may be made of a semiconductor material (e.g., gallium nitride).

Next, referring to FIG. 1B , a light emitting layer 140 ′ is formed on the second side S2 of the first semiconductor layer 130 ′, and the second side S2 is opposite to the first side S1. The light emitting layer 140 ′ can be grown on the first semiconductor layer 130 ′ by epitaxial growth, and the formation temperature of the light emitting layer 140 ′ is lower than the formation temperature of the first semiconductor layer 130 ′. In some embodiments, the light emitting layer 140 ′ can include a II-VI group material (e.g., zinc selenide (ZnSe)) or a III-V group nitride material (e.g., gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), or aluminum indium gallium nitride (AlInGaN)). In some embodiments, the structure of the light-emitting layer 140' is, for example, a multiple quantum well structure (MQW), which may include multiple layers of alternately stacked indium gallium nitride (InGaN) and multiple layers of gallium nitride (GaN). By designing the ratio of indium or gallium in the light-emitting layer 140', the light-emitting wavelength range of the light-emitting layer 140' can be adjusted, but the present invention is not limited thereto.

Next, referring to FIG. 1C , a second semiconductor layer 150 ′ is formed on the light emitting layer 140 ′. In some embodiments, the second semiconductor layer 150 ′ is grown on the light emitting layer 140 ′ by epitaxial growth, and its main material includes gallium nitride (GaN), but the present invention is not limited thereto. For example, the second semiconductor layer 150 ′ is a P-type doped semiconductor layer, and the material of the P-type doped semiconductor layer is, for example, P-type gallium nitride (p-GaN), and the formation temperature of the second semiconductor layer 150 ′ is lower than the formation temperature of the light emitting layer 140 ′. In other embodiments, the second semiconductor layer 150' may include a II-VI Group material (e.g., zinc selenide (ZnSe)) or a III-V Group nitride material (e.g., gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), or aluminum indium gallium nitride (AlInGaN)).

Next, please refer to FIG. 1D . In some embodiments, a transparent conductive layer 160 ′ may be formed on the second semiconductor layer 150 ′ after the second semiconductor layer 150 ′ is formed. The transparent conductive layer 160 ′ may be formed using a physical vapor deposition (PVD) process, such as vacuum sputtering or evaporation. The transparent conductive layer 160 ′ may include a transparent conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum tin oxide, aluminum zinc oxide, indium gallium zinc oxide, or nano silver, etc., but the present invention is not limited thereto.

In some embodiments, the transparent conductive layer 160' may be subjected to a thermal annealing process. In some embodiments, the temperature of the thermal annealing process is about 150°C to 300°C. In some embodiments, the temperature of the thermal annealing process is about 200°C to 250°C. In some embodiments, the time of the thermal annealing process is about 10 minutes to 60 minutes. In some embodiments, the time of the thermal annealing process is about 25 minutes to 35 minutes.

Next, referring to FIG. 1E , in some embodiments, a first insulating layer 170 ′ having an opening OI may be formed on the second semiconductor layer 150 ′ and the transparent conductive layer 160 ′. Next, a first electrode 180 is formed in the opening OI and on the second semiconductor layer 150 ′ and the transparent conductive layer 160 ′, so that the first electrode 180 can be electrically connected to the second semiconductor layer 150 ′. The first insulating layer 170 ′ may be formed using a chemical vapor deposition (CVD) process. The first insulating layer 170 ′ may include a transparent insulating material, such as silicon oxide, silicon nitride, silicon oxynitride, or a stack of the above materials, but the present invention is not limited thereto.

In some embodiments, the first electrode 180 can be formed using, for example, a vacuum sputtering process. The material of the first electrode 180 may include a high reflectivity conductive material, such as a high reflectivity metal such as aluminum, silver, titanium, or chromium. In some embodiments, the first electrode 180 may include a stack of multiple layers of metal, such as a stack of aluminum/titanium/tin (Al/Ti/Sn). In some embodiments, the thickness of the first electrode 180 is about 1 μm to 2 μm.

Next, referring to FIG. 1F , the growth substrate 110 and the film layer formed on the growth substrate 110 are flipped, and then the growth substrate 110 is removed to expose the buffer layer 120. In some embodiments, the growth substrate 110 can be removed by laser peeling or heat treatment. In some embodiments, the growth substrate 110 and the film layer formed thereon can be flipped and placed on a temporary substrate (not shown). In other words, the flipped first electrode 180 is located on a side close to the temporary substrate, and the growth substrate 110 is located on a side away from the temporary substrate. Next, in some embodiments, after removing the growth substrate 110, an etching process may be used to remove the buffer layer 120 to expose the first side S1 of the first semiconductor layer 130'.

Next, please refer to Figure 1G, the first semiconductor layer 130', the light-emitting layer 140' and the second semiconductor layer 150' are patterned to form a first semiconductor pattern 130, a light-emitting pattern 140 and a second semiconductor pattern 150 respectively, and the length L2 of the second semiconductor pattern 150 is greater than the length L1 of the first semiconductor pattern 130.

In some embodiments, the method of patterning the first semiconductor layer 130', the light-emitting layer 140' and the second semiconductor layer 150' can utilize an etching process, and the first semiconductor layer 130', the light-emitting layer 140' and the second semiconductor layer 150' can be patterned in sequence using the etchant required for each layer to form the first semiconductor pattern 130, the light-emitting pattern 140 and the second semiconductor pattern 150, respectively.

In some embodiments, after patterning the first semiconductor layer 130', the light emitting layer 140' and the second semiconductor layer 150', an etching process may be used to further pattern the transparent conductive layer 160' and the first insulating layer 170' using the etchant required for each layer to form the transparent conductive pattern 160 and the first insulating pattern 170.

Next, referring to FIG. 1H , a second insulating pattern 172 is formed on the sidewalls of the light-emitting pattern 140 and the second semiconductor pattern 150. In some embodiments, the second insulating pattern 172 is also formed on the sidewalls of the transparent conductive pattern 160 and the first insulating pattern 170, wherein the first semiconductor pattern 130, the light-emitting pattern 140, the second semiconductor pattern 150, the transparent conductive pattern 160, the first insulating pattern 170 and the second insulating pattern 172 may constitute a light-emitting stack LS. The second insulating pattern 172 may be formed using a chemical vapor deposition process. The second insulating pattern 172 may include a transparent insulating material, such as silicon oxide, silicon nitride, silicon oxynitride, or a stack of the above materials, but the present invention is not limited thereto.

Next, referring to FIG. 1I(a), a second electrode 190 is formed on the third side S3 and the fourth side S4 of the first semiconductor pattern 130, wherein the third side S3 is opposite to the fourth side S4, and the third side S3 is connected to the first side S1 and the second side S2, and the fourth side S4 is also connected to the first side S1 and the second side S2.

Please refer to FIG. 1I(a) to FIG. 1I(b) simultaneously, wherein FIG. 1I(a) may be a cross-sectional schematic diagram taken along the section line A-A' of FIG. 1I(b), the light-emitting element 10 includes: a first semiconductor pattern 130, a light-emitting pattern 140, a second semiconductor pattern 150, a first electrode 180, and a second electrode 190. The first semiconductor pattern 130 has a first side S1, a second side S2, a third side S3, and a fourth side S4, wherein the first side S1 is opposite to the second side S2, the third side S3 is opposite to the fourth side S4, and the third side S3 and the fourth side S4 connect the first side S1 and the second side S2. The second semiconductor pattern 150 is located at the second side S2 of the first semiconductor pattern 130, and the length L2 of the second semiconductor pattern 150 is greater than the length L1 of the first semiconductor pattern 130. The light-emitting pattern 140 is located between the first semiconductor pattern 130 and the second semiconductor pattern 150. The first electrode 180 is located at a side of the second semiconductor pattern 150 far from the first semiconductor pattern 130, and the first electrode 180 is electrically connected to the second semiconductor pattern 150. The second electrode 190 is located at the third side S3 and the fourth side S4 of the first semiconductor pattern 130, and the second electrode 190 is electrically connected to the first semiconductor pattern 130. In the light emitting element 10 of an embodiment of the present invention, the second electrode 190 is disposed on the third side S3 and the fourth side S4 of the first semiconductor pattern 130 , so that the bridging of the second electrode 190 is easier, thereby improving the bridging yield of the second electrode 190 .

In some embodiments, the second electrode 190 physically contacts the third side S3 and the fourth side S4 of the first semiconductor pattern 130, so that the second electrode 190 is electrically connected to the first semiconductor pattern 130. In some embodiments, the second electrode 190 can also be disposed on the fifth side S5 and the sixth side S6 of the first semiconductor pattern 130, wherein the fifth side S5 is opposite to the sixth side S6, and the fifth side S5 and the sixth side S6 are connected to the third side S3 and the fourth side S4, so that the second electrode 190 can surround the first semiconductor pattern 130.

In some embodiments, the length L3 of the first electrode 180 is about 30% of the length L2 of the second semiconductor pattern 150, but the present invention is not limited thereto. In other embodiments, the length L3 of the first electrode 180 is 20% to 90% of the length L2 of the second semiconductor pattern 150, and the longer the length L3 of the first electrode 180 is, the more it helps the luminous pattern 140 to recycle reflected light, thereby improving the light utilization rate of the luminous element 10.

In some embodiments, the light-emitting element 10 further includes a transparent conductive pattern 160, which is located between the first electrode 180 and the second semiconductor pattern 150. The transparent conductive pattern 160 can improve the current distribution uniformity of the second semiconductor pattern 150, increase the light-emitting area of the light-emitting element 10, and thus facilitate heat dissipation of the light-emitting element 10 and improve the light-emitting efficiency of the light-emitting element 10.

In some embodiments, the light-emitting element 10 further includes a first insulating pattern 170, which is located on the surface of the transparent conductive pattern 160 away from the second semiconductor pattern 150 to avoid unnecessary electrical connection between the transparent conductive pattern 160 and other conductive film layers. In some embodiments, the first insulating pattern 170 also surrounds the first electrode 180 to avoid unnecessary electrical connection between the first electrode 180 and other conductive film layers.

The light-emitting element 10 may further include a second insulating pattern 172, which is located on the sidewalls of the light-emitting pattern 140 and the second semiconductor pattern 150 to prevent electrical connection between the light-emitting pattern 140 and the second semiconductor pattern 150 and the second electrode 190, and the first semiconductor pattern 130, the light-emitting pattern 140, the second semiconductor pattern 150, the transparent conductive pattern 160, the first insulating pattern 170 and the second insulating pattern 172 may constitute a light-emitting stack LS of the light-emitting element 10. In other words, the light-emitting element 10 may include a first electrode 180, a second electrode 190 and a light-emitting stack LS. In some embodiments, the second insulating pattern 172 is further located on the sidewall of the transparent conductive pattern 160 to avoid unnecessary electrical connection between the transparent conductive pattern 160 and the second electrode 190. In some embodiments, the second insulating pattern 172 is further located on the sidewall of the first insulating pattern 170 to completely cover the light-emitting pattern 140, the second semiconductor pattern 150 and the sidewall of the transparent conductive pattern 160.

In the following, other embodiments of the present invention are further described using FIGS. 2 to 4 , and the component numbers and related contents of the embodiment of FIGS. 1I(a) to 1I(b) are used, wherein the same number is used to represent the same or similar components, and the description of the same technical contents is omitted. For the description of the omitted parts, reference can be made to the embodiment of FIGS. 1I(a) to 1I(b), and they will not be repeated in the following description.

2 is a cross-sectional view of a light emitting device 20 according to an embodiment of the present invention. The light emitting device 20 includes a first electrode 180A, a second electrode 190 and a light emitting stack LS, and the light emitting stack LS includes a first semiconductor pattern 130, a light emitting pattern 140, a second semiconductor pattern 150, a transparent conductive pattern 160, a first insulating pattern 170 and a second insulating pattern 172.

Compared with the light-emitting element 10 shown in FIGS. 1I(a) to 1I(b), the light-emitting element 20 shown in FIG. 2 is different mainly in that the length L3A of the first electrode 180A of the light-emitting element 20 is greater than the length L3 of the first electrode 180 of the light-emitting element 10. For example, the length L3A of the first electrode 180A of the light-emitting element 20 is approximately 80% of the length L2 of the second semiconductor pattern 150. In this way, the first electrode 180A can reflect more light back to the light-emitting pattern 140, thereby improving the light utilization rate of the light-emitting element 20.

3 is a cross-sectional view of a light emitting element 30 according to an embodiment of the present invention. The light emitting element 30 includes a first electrode 180A, a second electrode 190A and a light emitting stack LS, and the light emitting stack LS includes a first semiconductor pattern 130, a light emitting pattern 140, a second semiconductor pattern 150, a transparent conductive pattern 160, a first insulating pattern 170 and a second insulating pattern 172.

Compared with the light emitting element 20 shown in FIG. 2 , the light emitting element 30 shown in FIG. 3 is different mainly in that the second electrode 190A of the light emitting element 30 further includes a portion 192 formed on the first side S1 of the first semiconductor pattern 130 , and the portion 192 of the second electrode 190A does not completely cover the first semiconductor pattern 130 .

For example, the step of FIG. 1I (a) further includes forming a second electrode 190A on the first side S1 of the first semiconductor pattern 130, and the second electrode 190A further includes a portion 192 located on the first side S1 of the first semiconductor pattern 130. In some embodiments, the portion 192 of the second electrode 190A has an opening OE, and the opening OE exposes the first semiconductor pattern 130.

4 is a partial cross-sectional schematic diagram of a display device 100 according to an embodiment of the present invention. The display device 100 includes: a circuit substrate CS and a plurality of light emitting elements 40. The light emitting elements 40 are disposed on the circuit substrate CS and electrically connected to the circuit substrate CS, and the light emitting elements 40 can be any one of the light emitting elements 10, 20, 30 described above.

In some embodiments, the circuit substrate CS may include a bottom plate SB and a driving circuit layer DW. The bottom plate SB of the circuit substrate CS may be a transparent substrate or a non-transparent substrate, and its material may be a quartz substrate, a glass substrate, a polymer substrate or other appropriate materials, but the present invention is not limited thereto. The driving circuit layer DW may include components or circuits required by the display device 100, such as driving components, switching components, storage capacitors, power lines, driving signal lines, timing signal lines, current compensation lines, detection signal lines, etc.

In some embodiments, a driving circuit layer DW may be formed on the base substrate SB by using a thin film deposition process, a mask process, and an etching process, and the driving circuit layer DW may include an active element array, wherein the active element array includes a plurality of active elements arranged in an array, such as thin film transistors.

In some embodiments, the driving circuit layer DW includes a plurality of active devices TR and a wiring layer WL. In other embodiments, the driving circuit layer DW may further include other devices, such as passive devices, as needed.

The active element TR may be composed of a semiconductor layer CH, a gate GE, a source SE and a drain DE. The region of the semiconductor layer CH overlapping the gate GE may be regarded as a channel region of the active element TR. The gate GE, the source SE and the drain DE are electrically separate from each other, and the source SE and the drain DE may be electrically connected to two ends of the semiconductor layer CH, respectively. The gate GE and the source SE may receive signals from, for example, a driving element, respectively. The material of the semiconductor layer CH may include silicon semiconductor materials (such as polycrystalline silicon, amorphous silicon, etc.), oxide semiconductor materials, and organic semiconductor materials, but the present invention is not limited thereto. The materials of the gate GE, the source SE and the drain DE may include metals with good electrical conductivity, such as aluminum, molybdenum, titanium, copper and the like.

The wiring layer WL may be located on a plurality of active elements TR. In some embodiments, the wiring layer WL may include a plurality of insulating layers IL and a plurality of wire layers CL, wherein the plurality of wire layers CL are separated by the plurality of insulating layers IL to form a plurality of conductive lines, so that each active element TR can be electrically connected to, for example, a corresponding light-emitting element 40. In this way, the operation of the light-emitting element 40 can be controlled by controlling the signal sent to the active element TR.

In some embodiments, the display device 100 may include a plurality of pads PD1 and a plurality of pads PD2, wherein the plurality of pads PD1 may be electrically connected to corresponding active elements TR. For example, the plurality of pads PD1 and the plurality of pads PD2 may be disposed on a wiring layer WL, and may be electrically connected to a drain DE of the active element TR through a corresponding wiring layer CL or a conductive line in the wiring layer WL.

In some embodiments, pads PD1 and PD2 may belong to the same film layer or be located on the same plane, and the patterns of pads PD1 and PD2 are separated from each other. In some embodiments, multiple pads PD2 may have the same potential and be electrically connected to each other through corresponding wiring layers CL or conductive lines in wiring layer WL.

The light emitting element 40 includes a first electrode 480, a second electrode 490 and a light emitting stack LS, wherein the first electrode 480 is electrically connected to the pad PD1, and the second electrode 490 is electrically connected to the pad PD2. In some embodiments, the first electrode 480 physically contacts the pad PD1.

In some embodiments, the display device 100 further includes a planar layer PL having an opening OL, the planar layer PL is located on the circuit substrate CS, and the opening OL of the planar layer PL can expose the pad PD2. The height of the planar layer PL is less than the height of the light-emitting element 40. In other words, the height of the planar layer PL does not need to be close to the height of the second electrode 490. In some embodiments, the display device 100 further includes a transparent conductive layer TC1, and the transparent conductive layer TC1 is located on the planar layer PL and the light-emitting element 40. The transparent conductive layer TC1 is electrically connected to the second electrode 490 of the light-emitting element 40, and the transparent conductive layer TC1 can be electrically connected to the pad PD2 through the opening OL. In some embodiments, the transparent conductive layer TC1 physically contacts the second electrode 490. In this way, the second electrode 490 can be electrically connected to the pad PD2 through the transparent conductive layer TC1, and the bridge between the second electrode 490 and the transparent conductive layer TC1 is easier and has a high yield, thereby ensuring that the display device 100 has an improved production yield. In some embodiments, the height of the planar layer PL is about half the height of the light-emitting element 40, which can ensure the electrical connection between the second electrode 490, the transparent conductive layer TC1 and the pad PD2.

In some embodiments, the display device 100 further includes a protective layer PV, which can cover and protect the plurality of light-emitting elements 40 and the transparent conductive layer TC1. In some embodiments, the display device 100 further includes a transparent conductive layer TC2, which can be stacked on the transparent conductive layer TC1 and the protective layer PV to ensure electrical connection between the second electrode 490 and the pad PD2.

In summary, the light-emitting element of the present invention makes the bridging of the second electrode easier by arranging the second electrode on the third side and the fourth side of the first semiconductor pattern, thereby improving the bridging yield of the second electrode. In addition, the manufacturing method of the light-emitting element of the present invention can produce a light-emitting element having a structure that facilitates electrode bridging. In addition, the display device of the present invention includes a light-emitting element having a structure that facilitates electrode bridging, thereby having an improved production yield.

Although the present invention has been disclosed as above by the embodiments, they are not intended to limit the present invention. Any person 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 protection scope of the present invention shall be defined by the scope of the attached patent application.

10, 20, 30, 40: light-emitting element 100: display device 110: growth substrate 120: buffer layer 130: first semiconductor pattern 130': first semiconductor layer 140: light-emitting pattern 140': light-emitting layer 150: second semiconductor pattern 150': second semiconductor layer 160: transparent conductive pattern 160': transparent conductive layer 170: first insulating pattern 170': first insulating layer 172: second insulating pattern 180, 180A, 480: first electrode 190, 190A, 490: second electrode 192: part A-A’: section line CH: semiconductor layer CL: wiring layer CS: circuit substrate DE: drain DW: driver circuit layer GE: gate IL: insulation layer L1, L2, L3, L3A: length LS: light-emitting stack OE, OI, OL: opening PD1, PD2: pad PL: planar layer PV: protective layer S1: first side S2: second side S3: third side S4: fourth side S5: fifth side S6: sixth side SB: bottom plate SE: source TC1, TC2: transparent conductive layer TR: active element WL: wiring layer

Figures 1A to 1I(b) are partial cross-sectional schematic diagrams and partial top view schematic diagrams of the step flow of the manufacturing method of the light-emitting element 10 according to an embodiment of the present invention. Figure 2 is a cross-sectional schematic diagram of the light-emitting element 20 according to an embodiment of the present invention. Figure 3 is a cross-sectional schematic diagram of the light-emitting element 30 according to an embodiment of the present invention. Figure 4 is a partial cross-sectional schematic diagram of the display device 100 according to an embodiment of the present invention.

10: Light-emitting element

130: First semiconductor pattern

140: Luminous pattern

150: Second semiconductor pattern

160: Transparent conductive pattern

170: The first insulated pattern

172: The second insulating pattern

180: First electrode

190: Second electrode

L1, L2, L3: Length

LS: Luminescent layer

S1: First side

S2: Second side

S3: Third side

S4: Fourth side

Claims (19)

A light-emitting element comprises: a first semiconductor pattern having a first side, a second side, a third side and a fourth side, wherein the first side is opposite to the second side, the third side is opposite to the fourth side, and the third side and the fourth side are respectively connected to the first side and the second side; a second semiconductor pattern located on the second side of the first semiconductor pattern, and the length of the second semiconductor pattern is greater than the length of the first semiconductor pattern; a light-emitting pattern , located between the first semiconductor pattern and the second semiconductor pattern; a first electrode, located on a side of the second semiconductor pattern away from the first semiconductor pattern and electrically connected to the second semiconductor pattern; and a second electrode, located on the third side and the fourth side of the first semiconductor pattern and electrically connected to the first semiconductor pattern, wherein the second electrode physically contacts the third side and the fourth side of the first semiconductor pattern. A light-emitting element as described in claim 1, wherein the second electrode surrounds the first semiconductor pattern. A light-emitting element as described in claim 1, wherein the first electrode comprises a high-reflectivity conductive material. A light-emitting element as described in claim 1, wherein the length of the first electrode is 20% to 90% of the length of the second semiconductor pattern. A light-emitting element as described in claim 1, wherein the second electrode is also located on the first side of the first semiconductor pattern. A light-emitting element as described in claim 5, wherein the second electrode has a first opening, and the first opening exposes the first semiconductor pattern. A light-emitting element comprises: a first semiconductor pattern having a first side, a second side, a third side and a fourth side, wherein the first side is opposite to the second side, the third side is opposite to the fourth side, and the third side and the fourth side are respectively connected to the first side and the second side; a second semiconductor pattern located on the second side of the first semiconductor pattern, and the length of the second semiconductor pattern is greater than the length of the first semiconductor pattern; a light-emitting element; pattern, located between the first semiconductor pattern and the second semiconductor pattern; a first electrode, located on a side of the second semiconductor pattern far from the first semiconductor pattern and electrically connected to the second semiconductor pattern; a second electrode, located on the third side and the fourth side of the first semiconductor pattern and electrically connected to the first semiconductor pattern; and a first transparent conductive pattern, located between the first electrode and the second semiconductor pattern. A display device, comprising: a circuit substrate; and a plurality of light-emitting elements as described in any one of claims 1 to 7, disposed on the circuit substrate and electrically connected to the circuit substrate. The display device as described in claim 8 further includes a first pad and a second pad, wherein the first electrode is electrically connected to the first pad, and the second electrode is electrically connected to the second pad through a second transparent conductive layer. The display device as described in claim 8 further includes a protective layer covering the plurality of light-emitting elements and the second transparent conductive layer. A method for manufacturing a light-emitting element includes: forming a first semiconductor layer on a growth substrate, and a first side of the first semiconductor layer is close to the growth substrate; forming a light-emitting layer on a second side of the first semiconductor layer, and the second side is opposite to the first side; forming a second semiconductor layer on the light-emitting layer; forming a first electrode on the second semiconductor layer; removing the growth substrate; patterning the first semiconductor layer, the light-emitting layer and the second semiconductor layer to form a first semiconductor pattern, a light-emitting pattern and a second semiconductor pattern respectively, and the length of the second semiconductor pattern is greater than the length of the first semiconductor pattern; and forming a second electrode on a third side and a fourth side of the first semiconductor pattern, and the third side and the fourth side are respectively connected to the first side and the second side. The method for manufacturing a light-emitting element as described in claim 11 further includes forming a buffer layer on the growth substrate before forming the first semiconductor layer. The method for manufacturing a light-emitting element as described in claim 12 further includes removing the buffer layer after removing the growth substrate. The method for manufacturing a light-emitting element as described in claim 11 further includes forming a first transparent conductive layer on the second semiconductor layer after forming the second semiconductor layer. The method for manufacturing a light-emitting element as described in claim 14 further includes performing an annealing process on the first transparent conductive layer. The method for manufacturing a light-emitting element as described in claim 14 further includes patterning the first transparent conductive layer after patterning the first semiconductor layer, the light-emitting layer, and the second semiconductor layer to form a first transparent conductive pattern. The method for manufacturing a light-emitting element as described in claim 11 further includes forming a first insulating layer having a second opening on the second semiconductor layer before forming the first electrode, and the first electrode is formed in the second opening. The method for manufacturing a light-emitting element as described in claim 11 further includes forming a second insulating pattern on the sidewalls of the light-emitting pattern and the second semiconductor pattern before forming the second electrode. The method for manufacturing a light-emitting element as described in claim 11 further includes forming the second electrode on the first side of the first semiconductor pattern, and the second electrode does not completely cover the first semiconductor pattern.

Images