TWM619674U - Light-emitting device - Google Patents

Abstract

The invention provides a light-emitting element whose structure is formed by epitaxial technology from bottom to top. A substrate, a distributed Bragg reflector (DBR) layer, a lower cladding layer, an active layer, and an upper cladding layer are sequentially formed by epitaxial technology. And a window layer; wherein the DBR layer has a plurality of sub-DBR layers and is called a multi-stage DBR layer, and the thickness of the plurality of sub-DBR layers is different from each other. The combination of multiple sub-DBR layers with different thicknesses can extend the wavelength range of the stop band of the DBR layer to 80% height, so that the wavelength range of the stop band 80% height of the multi-stage DBR layer is higher than that of the single-stage DBR layer (with only one sub-layer). The traditional light-emitting element of the DBR layer) is also wide, so that the total luminous energy and luminous flux of the new-type light-emitting element are improved.

Description

Light-emitting element

The present invention relates to a light-emitting element, in particular to a light-emitting element having a distributed Bragg reflector (DBR) layer of multiple stacked pairs of different thicknesses, so as to combine the active layer (active layer) The short wavelength and the long wavelength in the emission wavelength range are reflected to the window layer, so that the light-emitting element can exhibit the highest total light emission energy (total power) in the window layer.

Light-emitting devices include light-emitting diodes (Light-Emitting Diode, LED) and laser diodes (Laser Diode, LD). In particular, LEDs are divergent light sources. Connecting surface or pin connecting surface to achieve the purpose of light emission. Please refer to Figure 1. One of the light-emitting elements in the conventional technology is formed by epitaxial, and its structure from bottom to top includes: a substrate (substate) 1, a distributed Bragg reflector layer 2, a bottom coating Layer (lower cladding layer) 3, an active layer 4, an upper cladding layer (upper cladding layer) 5 and a window layer (window layer) 6, under the substrate (substate) 1 is a lower electrode (electrode) 8 As for the window layer 6, an upper electrode 7 is formed. Generally speaking, after the upper electrode 7 and the lower electrode 8 are energized, a part of the light generated by the active layer 4 will radiate toward the window layer 6 to cause the light-emitting element to emit light. However, another part of the light generated by the active layer 4 will radiate from the active layer 4 toward the DBR layer 2. At this time, the light is reflected toward the active layer 4 and the window layer 6 through the reflection of the DBR layer 2 Direction and radiate through the window layer 6 to form light, thereby improving the luminous intensity and luminous efficiency of the light-emitting element.

Generally, the DBR layer 2 is composed of multiple stacked pairs repeatedly stacked, and each stacked pair includes an upper layer and a lower layer. In the multiple stacked pairs, each upper layer has the same thickness, and each lower layer also has the same thickness. Thickness, and usually the thickness of the upper layer and the thickness of the lower layer are not the same. In other words, each of the plurality of stacked pairs has the same thickness. In addition to the factors of the materials used, the thickness of the upper layer, the thickness of the lower layer, and the thickness of the stack pair determine the design wavelength (target wave length) of the light from the active layer 4 that the DBR layer 2 reflects. Please refer to Figure 2, where Figure 2(a) is the luminous intensity and luminous wavelength range of the active layer 4 during the operation of the aforementioned conventional light-emitting device. The luminous wavelength range (between 585nm and 685nm, the peak wavelength is 635nm) can be divided from left to right into adjacent short wavelength range A (between 585nm and 610nm), dominant wavelength range B (between 610nm and 660nm) and long wavelength range C (between 660nm and 685nm); Figure 2 (b) is the reflectance spectrum of the DBR layer 2 during the operation of the aforementioned conventional light-emitting element. Obviously, the stopband D with high reflectivity only corresponds to the main wavelength range B, while the short wavelength range A And the long wavelength range C is not reflected by the DBR layer 2 toward the window layer 6, and the aforementioned design wavelength (635 nm) is usually a wavelength approximately in the center of the stop zone D.

Each stacked pair in the aforementioned DBR layer 2 has the same thickness, and the DBR layer 2 can be called a single-stage DBR layer. Therefore, for the aforementioned conventional light-emitting element using a single-stage DBR layer, the total luminous energy measured in the window layer 6 does not include the energy in the short wavelength range A and the long wavelength range C. In other words, the conventional light-emitting element using the single-stage DBR layer loses the luminous energy in the short wavelength range A and the long wavelength range C.

In view of the above problems, the purpose of the present invention is to provide a light-emitting element that can reflect the short wavelength range, the dominant wavelength range and the long wavelength range in the light-emitting wavelength range from an active layer, so that the light-emitting element is in a window layer. Can show the highest total luminous energy.

To achieve the above objective, the present invention discloses a light-emitting device, which at least includes: a substrate; a distributed Bragg reflector (DBR) layer, the DBR layer is disposed above the substrate; a lower cladding layer, the lower cladding layer Is disposed above the DBR layer; an active layer, the active layer is disposed above the lower cladding layer; an upper cladding layer, the upper cladding layer is disposed above the active layer; a window layer, the window The layer is arranged above the upper cladding layer; wherein, the DBR layer has a plurality of sub-DBR layers, and the thickness of the plurality of sub-DBR layers is different from each other.

In another embodiment, the plurality of sub-DBR layers are respectively a first sub-DBR layer and a second sub-DBR layer, and the thickness of the second sub-DBR layer is greater than the thickness of the first sub-DBR layer.

In another embodiment, the second sub-DBR is stacked on top of the first sub-DBR layer.

In another embodiment, the first sub-DBR is stacked on top of the second sub-DBR layer.

In another embodiment, a light-emitting wavelength range of the active layer is divided from left to right into a short wavelength range, a main wavelength range, and a long wavelength range that are successively adjacent to each other, and the reflection of the first sub-DBR layer comes from the active Layer of light in the dominant wavelength range.

In another embodiment, the second sub-DBR layer reflects light in the long wavelength range from the active layer.

In another embodiment, the second sub-DBR layer reflects light in the short wavelength range from the active layer.

In another embodiment, a first sub-DBR layer, a second sub-DBR layer, and a third sub-DBR layer are superimposed on a plurality of the sub-DBR layers from bottom to top; or, a plurality of the sub-DBR layers are stacked from bottom to top. The first sub-DBR layer, the second sub-DBR layer, the third sub-DBR layer, and a fourth sub-DBR layer are stacked on top; or, a plurality of the sub-DBR layers are stacked from bottom to top with the first sub-DBR layer. A sub-DBR layer, the second sub-DBR layer, the third sub-DBR layer, the fourth sub-DBR layer, and a fifth sub-DBR layer; the first sub-DBR layer, the second sub-DBR layer, the third sub-DBR layer The thickness of the sub-DBR layer, the fourth sub-DBR layer, and the fifth sub-DBR layer are different from each other.

In another embodiment, the substrate is GaAs, the active layer is AlGaInP, and the DBR layer is AlGaAs.

In another embodiment, the substrate, the DBR layer, and the lower cladding layer are of a first conductivity type, and the upper cladding layer and the window layer are of a second conductivity type; when the first conductivity type is an n-type , The second conductivity type is p-type; or, when the first conductivity type is p-type, the second conductivity type is n-type.

In order to enable those with ordinary knowledge in the field to clearly understand the content of this new model, please refer to the following descriptions and diagrams.

First of all, please refer to Figure 3, a light-emitting element (Light-Emitting Diode, LED) 100 of the present invention, the light-emitting element 100 can be a light-emitting diode (Light-Emitting Diode, LED) and a laser diode (Laser Diode, LD). In order to facilitate the understanding of the spirit of the present invention, the following embodiments take the structure of the LED as an example. However, those skilled in the art should understand that the spirit and structure of the present invention are also applicable to LD. The light-emitting element 100 includes at least: a first electrode 10; a substrate 11, the substrate 11 being in contact with the first electrode 10, the substrate 11 may be disposed above or below the first electrode 10; and a distributed Bragg reflector Mirror (Distributed Bragg Reflector, DBR) layer 12, the DBR layer 12 is disposed above the substrate 11, the DBR layer 12 can be in contact with the upper surface of the substrate 11; the lower cladding layer 13, the lower cladding layer 13 is disposed Above the DBR layer 12, the lower cladding layer 13 can be in contact with the upper surface of the DBR layer 12; an active layer 14, the active layer 14 is disposed on the lower cladding layer 13, the active layer 14 can Contact with the upper surface of the lower cladding layer 13; an upper cladding layer 15, the upper cladding layer 15 is disposed above the active layer 14, the upper cladding layer 15 can be in contact with the upper surface of the active layer 14 A window layer 16, the window layer 16 is provided above the upper cladding layer 15, the window layer 16 can be in contact with the upper surface of the upper cladding layer 15; a second electrode 17, the second electrode 17 is provided Above the window layer 16, the second electrode 17 can be in contact with the window layer 16. In other words, the structure of the light-emitting device 100 is sequentially formed from bottom to top by epitaxial technology: the substrate 11, the DBR layer 12, the lower cladding layer 13, the active layer 14, the upper cladding layer 15 And the window layer 16, for example, molecular beam epitaxy (MBE), metal organic vapor phase epitaxy (MOPVE), low pressure vapor phase epitaxy (Low Pressure Vapor Phase Epitaxial) Method, LPMOVPE) or Metal Organic Chemical Vapor Deposition (MOCVD) and other related technologies are formed in-suit in the chamber.

The substrate 11 is a first conductivity type substrate, such as n-type gallium arsenide (GaAs), with a thickness between 250 μm and 300 μm. The DBR layer 12 is a first conductivity type DBR layer, such as an n-type DBR layer, and the DBR layer 12 may be aluminum gallium arsenide (AlGaAs). The lower cladding layer 13 is a first conductivity type cladding layer, for example, an n-type cladding layer. The lower cladding layer 13 may be aluminum arsenide (AlAs) and/or aluminum gallium arsenide (AlGaAs). The active layer 14 may be, for example, undoped aluminum gallium indium phosphide (AlGaInP), with a thickness of about 0.1 to 2 μm. The upper cladding layer 15 is a second conductivity type cladding layer, for example, a p-type cladding layer. The upper cladding layer 15 may be aluminum arsenide (AlAs) and/or aluminum gallium arsenide (AlGaAs). Both the lower cladding layer 13 and the upper cladding layer 15 are anti-reflection stacks, which prevent the light generated by the active layer 14 from being in the lower cladding layer 13/the active layer 14 The junction (lower junction, not numbered in the figure) and the junction of the upper cladding layer 15/the active layer 14 (upper junction, not numbered in the figure) reflect, the lower cladding layer 13 and the upper cladding layer 15 also prevents the light generated by the active layer 14 from resonating between the upper junction and the lower junction. The window layer 16 is a second conductivity type window layer, such as a p-type window layer. The window layer 16 has a wider or indirect energy gap and higher conductivity. The window layer 16 can be gallium phosphide (GaP), gallium arsenide phosphorous (GaAsP) or aluminum gallium arsenide (AlGaAs). The first electrode 10 is a first conductivity type electrode, such as an n-type electrode; the second electrode 17 is a second conductivity type electrode, such as a p-type electrode; the n-type electrode may be AuGeNi (AuGeNi) alloy , And the p-type electrode can be beryllium gold (BeAu) alloy. In other words, when the first conductivity type is n-type, the second conductivity type is p-type; or, when the first conductivity type is p-type, the second conductivity type is n-type.

The DBR layer 12 is a multi-stage DBR layer, which is different from the traditional light-emitting device using a single-stage DBR layer. The DBR layer 12 has a plurality of stacked sub-DBR layers 120, and the aforementioned multi-stage DBR layer refers to a DBR layer having a plurality of sub-DBR layers 120, and each sub-DBR layer 120 has a different thickness. In other words, the thicknesses of the plurality of sub-DBR layers 120 are different from each other. The aforementioned single-stage DBR layer refers to a DBR layer with only one sub-DBR layer. Each sub-DBR layer 120 is formed by repeatedly stacking a plurality of stacked pairs 121, and each stacked pair 121 includes a lower stacked layer 1211 and an upper stacked layer 1212. The material of the lower stack layer 1211 is Al _x Ga _1-x As and the material of the upper stack layer 1212 is Al _y Ga _1-y As, where 0<x<1, 0<y<1, and y is greater than 8 times x.

Please also refer to FIG. 4, in the first embodiment of the present invention, the DBR layer 12 may be called a second-order DBR layer (having two sub-DBR layers 120), for example, a plurality of sub-DBR layers 120 are respectively a first A sub-DBR layer 120' and a second sub-DBR layer 120" stacked on top of the first sub-DBR layer 120', the first sub-DBR layer 120' is formed by repeatedly stacking a plurality of first stacked pairs 121' The second sub-DBR layer 120" is formed by repeatedly stacking a plurality of second stacking pairs 121". Each of the first stacked pairs 121' includes a first lower stacked layer 1211' and a first upper stacked layer 1212', and each of the second stacked pairs 121" includes a second lower stacked layer 1211" and a The second upper stack layer 1212". The thicknesses of the first sub-DBR layer 120' and the second sub-DBR layer 120" are different from each other. More specifically, the first stacked pair 121' and the second stacked pair 121" have different thicknesses from each other. The thickness is different. Of course, the thickness of the first lower stacked layer 1211' and the second lower stacked layer 1211" may be different from each other, and the first upper stacked layer 1212' and the second upper stacked layer 1212" may be different from each other. The thickness is different between.

The active layer 14 may be a multiple quantum well structure, where the multiple quantum well structure includes a plurality of alternately formed quantum well layers and barrier layers. The material of the multiple quantum well structure can be obtained by changing the aluminum content in AlGaInP. For the quantum well layer, its constituent material can be aluminum gallium indium phosphide (AlxGaInP, x=0-0.5), and the material of the energy barrier layer can be aluminum gallium indium phosphide (AlxGaInP, x=0.3-1) quantum The thickness of the well layer and the energy barrier layer can be 20 and 500 angstroms, respectively. Please refer to Fig. 5(a) and Fig. 5(b) together, the active layer 14 is AlGaInP, and its emission wavelength range is between 585nm and 685nm, and the peak wavelength is 635nm. This emission wavelength range is divided from left to right into the adjacent short wavelength range A'(between 585nm and 610nm), the dominant wavelength range B'(between 610nm and 660nm) and the long wavelength range C'(between 660nm and 685nm). between). In this embodiment, a first design wavelength in the center of the stop band in the reflection spectrum of the first sub-DBR layer 120' is 630 nm to reflect the aforementioned short wavelength range A'and main wavelength range from the active layer 14 B'light. Since the thickness of the DBR layer 12 determines the design wavelength of the DBR layer 12 reflecting the light from the active layer 14, a thicker DBR layer can reflect a longer design wavelength, so the present invention makes the second sub-DBR layer 120' The thickness of the first sub-DBR layer 120' is greater than the thickness of the first sub-DBR layer 120', and a second design wavelength in the center of the stop band in the reflection spectrum of the second sub-DBR layer 120" is 670nm to reflect from the active layer 14 Light in the aforementioned long wavelength range C'and dominant wavelength range B'. In other words, in this embodiment, the first sub-DBR layer 120' and the second sub-DBR layer 120" respectively reflect different wavelength ranges of the light emitted from the active layer 14, and the second sub-DBR layer 120 The second design wavelength of 670 nm is greater than the first design wavelength 630 nm of the first sub-DBR layer 120'. From Figure 5(b), it can be clearly seen that the wavelength range of the stop band of the light-emitting element of the first embodiment using the second-order DBR layer of the present invention is between 605 nm and 695 nm (stop band 80%). The height of the wavelength range is 84 nm), and the stop band wavelength range of the traditional light-emitting element using a single-stage DBR layer is between 610 nm and 660 nm (the stop band 80% height of the wavelength range is 49 nm). Since the light-emitting element 100 of the first embodiment using the second-order DBR layer has a wider stop band wavelength range (80% of the stop band height is 80 nm), the short wavelength range A'and the main wavelength range B from the active layer 14 The light of'and the long wavelength range C'is reflected by the DBR layer 12 and radiates toward the window layer 16, so the total luminous energy measured on the window layer 16 has a power of about 2.51 mW. However, the conventional light-emitting element (design wavelength 635nm) using a single-stage DBR layer has a narrow stop band wavelength range (the stop band is 80% of the height of the wavelength range 49nm), so only the dominant wavelength range from the active layer 14 ( After being reflected by the DBR layer 12, the light between 610 nm and 660 nm will radiate toward the window layer 16. Therefore, the total luminous energy measured on the window layer 16 has a power of only about 2.15 mW. Obviously, the total luminous energy of the light-emitting element of the first embodiment using the second-level DBR layer is 1.17 times the total luminous energy of the conventional light-emitting element using the single-level DBR layer. In other words, the light-emitting element of the first embodiment using the second-level DBR layer increases the total luminous energy measured in the window layer 16. In addition, the luminous flux (brightness) of the light-emitting element of the first embodiment using the second-order DBR layer was also measured on the window layer 16 to be 1.9 times that of the conventional light-emitting element without the DBR layer, while the conventional light-emitting element using the single-stage DBR layer The luminous flux of the device is only 1.6 times the luminous flux of the conventional light-emitting device without the DBR layer. Obviously, the luminous flux of the first embodiment light-emitting device using the second-order DBR layer is 1.19 times the luminous flux of the conventional light-emitting device using the single-stage DBR layer. In other words, the light-emitting element of the first embodiment using the second-order DBR layer increases the luminous flux measured at the window layer 16.

The second embodiment of the present invention is similar to the first embodiment, and the difference between the second embodiment and the first embodiment is that in the second embodiment, the first sub-DBR layer 120' is stacked on the second sub-DBR Layer 120" is above rather than below. Of course, when designing the first embodiment and the second embodiment, the thickness of the second sub-DBR layer 120'' may be smaller than the thickness of the first sub-DBR layer 120'.

The other embodiments are the third embodiment, the fourth embodiment, and the fifth embodiment. They are a third-order DBR layer with three such sub-DBR layers, a fourth-order DBR layer with four such sub-DBR layers, A fifth-order DBR layer with five such sub-DBR layers. The third embodiment is similar to the first embodiment, and the difference between the third embodiment and the first embodiment is that in the third embodiment, a plurality of the sub-DBR layers 120 are stacked with the first sub-layers from bottom to top. The DBR layer 120', the second sub-DBR layer 120", and a third sub-DBR layer (not shown in the figure). The difference between the fourth embodiment and the third embodiment is that in the fourth embodiment, a plurality of the sub-DBR layers 120 further include a fourth sub-DBR layer (not shown in the figure) stacked on the third sub-DBR layer Above. The difference between the fifth embodiment and the fourth embodiment is that in the fifth embodiment, a plurality of the sub-DBR layers 120 further includes a fifth sub-DBR layer (not shown in the figure) stacked on the fourth sub-DBR layer Above. In particular, the stacking order of the first sub-DBR layer, the second sub-DBR layer, the third sub-DBR layer, the fourth sub-DBR layer, and the fifth sub-DBR layer can also be changed according to requirements. Of course, in the foregoing first to fifth embodiments, the first sub-DBR layer 120', the second sub-DBR layer 120", the third sub-DBR layer, the fourth sub-DBR layer, and the fifth sub-DBR layer The thickness of the sub-DBR layers are different from each other, so the corresponding design wavelengths in the center of the respective stop bands are also different. In other words, the first sub-DBR layer 120', the second sub-DBR layer 120", the third sub-DBR layer, the fourth sub-DBR layer, and the fifth sub-DBR layer respectively correspond to the first design wavelength The second design wavelength, a third design wavelength, a fourth design wavelength, and a fifth design wavelength are also different. For example, in the fourth embodiment, the first design wavelength is 600 nm, the second design wavelength is 635 nm, the third design wavelength is 670 nm, and the fourth design wavelength is 700 nm. The fourth sub-DBR layer, the third sub-DBR layer, the second sub-DBR layer 120" and the first sub-DBR layer 120' are superimposed thereon. Please also refer to Fig. 6, using a conventional light-emitting element with a single-stage DBR layer, the stop band 80% of the height of the wavelength interval is only 67nm, using the third embodiment of the new light-emitting element with a three-stage DBR layer, the stop band 80 The wavelength range of the% height can be extended to 87nm, and the wavelength range of the stop band 80% height of the light-emitting element with the fourth-order DBR layer of the fourth embodiment of the present invention can be extended to 95nm, and the fifth-order DBR layer of the present invention is used. The wavelength range of the stop band 80% of the height of the light-emitting element of the embodiment can be extended to 104 nm. Similar to the discussion of the light-emitting element of the first embodiment, the light-emitting element of the third embodiment, the light-emitting element of the fourth embodiment, and the light-emitting element of the fifth embodiment have higher total luminous energy and luminous flux than the conventional light-emitting element. Moreover, the order of the total luminous energy and the luminous flux is as follows: the light-emitting element of the fifth embodiment, the light-emitting element of the fourth embodiment, the light-emitting element of the third embodiment, the light-emitting element of the first embodiment, and the conventional light-emitting element.

The present invention uses a combination of multi-stage DBR layers (a plurality of sub-DBR layers 120), and each sub-DBR layer 120 has a different thickness, that is, the thickness of the plurality of sub-DBR layers 120 is different from each other. Since the thickness of the sub-DBR layer 120 determines the design wavelength of the sub-DBR layer 120 to reflect the light from the active layer 14, the combination of a plurality of sub-DBR layers 120 can extend the wavelength range of the stop band 80% height, so that the stop band 80 The wavelength range of% height is wider than that of a traditional light-emitting element using a single-stage DBR layer (only one sub-DBR layer), so that the total luminous energy and luminous flux of the new light-emitting element are improved.

However, the above are only the preferred embodiments of the present model, and should not be used to limit the scope of implementation of the present model, that is, simple equivalent changes and modifications made in accordance with the scope of the patent application for the present model and the description of the model, All are still within the scope of this new patent. In addition, any embodiment of the present invention or the scope of the patent application does not have to achieve all the objectives or advantages or features disclosed in the present invention. In addition, the abstract part and title are only used to assist the search of patent documents, not to limit the scope of the rights of this model. In addition, the terms "first" and "second" mentioned in this specification or the scope of the patent application are only used to name the element (element) or to distinguish different embodiments or ranges, and are not used to limit the number of elements. Upper or lower limit.

[Tradition] 1: base 2: DBR layer 3: Lower cladding layer 4: active layer 5: Upper cladding layer 6: Window layer 7: Upper electrode 8: Lower electrode A: Short wavelength range B: Dominant wavelength range C: Long wavelength range D: Stop band [This new model] 100: light-emitting element 10: The first electrode 11: Base 12: DBR layer 120: Sub DBR layer 120’: The first sub-DBR layer 120’’: The second sub-DBR layer 121: Stacked Pair 121’: The first stacking pair 1211’: The first lower stack 1212’: The first upper stack layer 121’’: Second stacked pair 1211’’: The second lower stack 1212’’: The second upper stack layer 1211: Lower stacking layer 1212: upper stacking layer 13: Lower cladding layer 14: active layer 15: Upper cladding layer 16: window layer 17: second electrode A’: Short wavelength range B’: Dominant wavelength range C’: Long wavelength range

Figure 1 is a cross-sectional view of the structure of a conventional light-emitting element. Figure 2(a) is a schematic diagram of the emission wavelength range of the active layer of a conventional light-emitting device. Figure 2(b) is a schematic diagram of the reflectance spectrum of a single-stage DBR layer of a conventional light-emitting device. Figure 3 is a cross-sectional view of the structure of the new type of light-emitting element. Figure 4 is a cross-sectional view of the structure of the novel light-emitting device with a second-stage DBR layer. Figure 5(a) is a schematic diagram of the light-emitting wavelength range of the active layer of the new light-emitting element. Figure 5(b) is a schematic diagram of the reflectance spectrum of the new light-emitting device with a second-order DBR layer. Figure 6 is a schematic diagram of the reflectance spectra of the third-, fourth- and fifth-order DBR layers of the new light-emitting device.

100: light-emitting element

10: The first electrode

11: Base

12: DBR layer

120: Sub DBR layer

121: Stacked Pair

1211: Lower stacking layer

1212: upper stacking layer

13: Lower cladding layer

14: active layer

15: Upper cladding layer

16: window layer

17: second electrode

Claims (10)

A light-emitting element at least includes: a substrate; a distributed Bragg reflector (DBR) layer, the DBR layer is disposed above the substrate; a lower cladding layer, the lower cladding layer is disposed above the DBR layer; An active layer, the active layer is disposed above the lower cladding layer; an upper cladding layer, the upper cladding layer is disposed above the active layer; a window layer, the window layer is disposed on the upper cladding layer Wherein, the DBR layer has a plurality of sub-DBR layers, and the thickness of the plurality of sub-DBR layers is different from each other. The light-emitting element according to claim 1, wherein the plurality of sub-DBR layers are respectively a first sub-DBR layer and a second sub-DBR layer, and the thickness of the second sub-DBR layer is greater than the thickness of the first sub-DBR layer . The light-emitting element according to claim 2, wherein the second sub-DBR is stacked on the first sub-DBR layer. The light-emitting element according to claim 2, wherein the first sub-DBR is stacked on the second sub-DBR layer. The light-emitting element according to claim 2, wherein a light-emitting wavelength range of the active layer is divided from left to right into a short wavelength range, a main wavelength range, and a long wavelength range that are successively adjacent to each other, and the first sub-DBR layer The light from the dominant wavelength range of the active layer is reflected. The light-emitting element according to claim 5, wherein the second sub-DBR layer reflects light in the long wavelength range from the active layer. The light-emitting element according to claim 5, wherein the second sub-DBR layer reflects light in the short wavelength range from the active layer. The light-emitting element according to claim 1, wherein a first sub-DBR layer, a second sub-DBR layer, and a third sub-DBR layer are superimposed on a plurality of sub-DBR layers from bottom to top; or, a plurality of sub-DBR layers The DBR layer is stacked from bottom to top with the first sub-DBR layer, the second sub-DBR layer, the third sub-DBR layer, and a fourth sub-DBR layer; or, a plurality of the sub-DBR layers are stacked from bottom to top The first sub-DBR layer, the second sub-DBR layer, the third sub-DBR layer, the fourth sub-DBR layer, and a fifth sub-DBR layer are arranged; the first sub-DBR layer, the second sub-DBR layer The thickness of the third sub-DBR layer, the fourth sub-DBR layer, and the fifth sub-DBR layer are different from each other. The light-emitting device according to claim 1, wherein the substrate is GaAs, the active layer is AlGaInP, and the DBR layer is AlGaAs. The light-emitting device according to claim 1, wherein the substrate, the DBR layer and the lower cladding layer are of a first conductivity type, and the upper cladding layer and the window layer are of a second conductivity type; If the type is n-type, the second conductivity type is p-type; or, when the first conductivity type is p-type, the second conductivity type is n-type.

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