Multiple quantum well structure, light emitting diode and light emitting assembly

Abstract

A multiple quantum well structure (10), a light emitting diode and a light emitting component, the multiple quantum well structure (10) comprising at least one stack of a first film layer (111), an interposed layer (112) and a second film layer (113), the at least one stack being multiple and stacked with each other. The interposed layer (112) is located between the first film layer (111) and the second film layer (113). The interposed layer (112) comprises a single structure and / or a superlattice structure. The first film layer comprises In, Ga and N, the interposed layer comprises Al, Ga and N, and the second film layer comprises Ga and N. The multiple quantum well structure can emit light of a longer wavelength and prevent defects and the like from occurring due to low-temperature epitaxial growth of the first film layer.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the technical field of light emitting diode, and in particular to a multi-quantum well structure, a light emitting diode and a light emitting assembly. BACKGROUND

[0002] A semiconductor light emitting diode (LED) utilizes injected electron holes to radiate light in a multi-quantum well, and accordingly, the greater the electron hole recombination radiation probability, the higher the light emitting efficiency of the LED.

[0003] However, due to the current multi-quantum well structure design, the light emitting efficiency of the electron holes in the multi-quantum well is limited, and the band gap width is difficult to reduce, thereby making it difficult to realize long-wavelength light emission. SUMMARY

[0004] In the multi-quantum well structure, In can be incorporated into the film layer for light emission to reduce the band gap width thereof, so as to emit long-wavelength light. Therefore, whether the film layer for light emission can excite long-wavelength light and the intensity (flux, etc.) of the excited light will be limited by the incorporation efficiency of In. In can be incorporated into the film layer by reducing the epitaxial temperature, but the way of reducing the epitaxial temperature will cause the probability of defects in the film layer in the multi-quantum well to increase sharply, and even cause the multi-quantum well structure to be unable to effectively emit light.

[0005] Therefore, embodiments of the present disclosure relate to a multi-quantum well structure, a light emitting diode and a light emitting assembly, which can solve the above technical problems.

[0006] In one aspect, the present disclosure provides a multi-quantum well structure, which includes at least one stack composed of a first film layer, an interposed layer and a second film layer. The interposed layer is located between the first film layer and the second film layer. The interposed layer includes a single structure and / or a superlattice structure. The first film layer includes In, Ga and N, the interposed layer includes Al, Ga and N, and the second film layer includes Ga and N.

[0007] For example, in the multi-quantum well structure provided in one embodiment of the first aspect of the present disclosure, the band gap width of the interposed layer is greater than the band gap width of the first film layer and the second film layer.

[0008] For example, in the embodiments of the present disclosure, the first film layer can be a potential well layer (quantum well), the second film layer can be a potential barrier layer (quantum barrier), and the interposed layer can be an interposed layer. For example, in each stack, the first film layer, the interposed layer and the second film layer are sequentially formed (grown), i.e., the interposed layer is grown on the first film layer, and then the second film layer is grown on the interposed layer.

[0009] After the insertion layer is inserted between the first film layer and the second film layer, the insertion layer including Al, Ga and N is different from the first film layer including In, Ga and N in terms of the band gap and the lattice constant, which causes a strong built-in electric field in the first film layer, and under the condition of a forward bias, the actual conduction band level of the first film layer is bent downward and the band gap is narrowed, so that the first film layer can emit light of a longer wavelength compared with the case where the insertion layer is not provided, and in this process, the first film layer does not need to be grown by low-temperature epitaxy, preventing defects and other adverse effects caused by low-temperature epitaxy of the first film layer.

[0010] In addition, for the multi-quantum well structure in the above scheme, without the insertion layer, the lattice size of the first film layer including In, Ga and N and the second film layer including Ga and N is greatly different, resulting in poor crystal quality of the multi-quantum well structure and causing the well proximity effect (WPE) to be extremely low, and even the multi-quantum well structure cannot effectively emit light. After the insertion layer is inserted between the first film layer and the second film layer, the lattice difference between the first film layer and the insertion layer and between the insertion layer and the second film layer is small, for example, the lattice difference between the first film layer and the insertion layer and the lattice difference between the insertion layer and the second film layer are smaller than the lattice difference between the first film layer and the second film layer.

[0011] For example, in the multi-quantum well structure provided in the first aspect of the present disclosure, the insertion layer includes GaN material and AlGaN material.

[0012] For example, in the multi-quantum well structure provided in the first aspect of the present disclosure, the GaN material and the AlGaN material included in the insertion layer are formed into a superlattice structure.

[0013] The GaN and AlGaN in the insertion layer can form a superlattice structure (SLs), which can provide better carrier injection efficiency compared with the case where the insertion layer only includes AlGaN, thereby improving the overall light emission efficiency of the multi-quantum well structure.

[0014] For example, in the multi-quantum well structure provided in the first aspect of the present disclosure, the insertion layer further includes In material, and the insertion layer further includes InAlGaN. For example, the insertion layer includes GaN material and InAlGaN material.

[0015] For example, in the multi-quantum well structure provided in the first aspect of the present disclosure, the GaN material and the InAlGaN material included in the insertion layer are formed into a superlattice structure.

[0016] By incorporating In material in the insertion layer, the generation of point defects during epitaxial growth of the insertion layer and the stress between film layers can be suppressed, thereby further improving the quality, light emission efficiency of the multi-quantum well structure and suppressing the separation and precipitation of In (e.g., In in the potential well layer).

[0017] For example, in some embodiments of the first aspect of the present disclosure, the content of Al in the insertion layer gradually increases in the direction from the first film layer to the second film layer. The multi-quantum well structure in this scheme can realize the function of emitting light with longer electroluminescent wavelength.

[0018] For example, in some embodiments of the first aspect of the present disclosure, the insertion layer comprises a single structure composed of AlGaN, wherein the content of Al in the single structure composed of AlGaN is 0.5% to 30%.

[0019] For example, in some embodiments of the first aspect of the present disclosure, the insertion layer comprises a single structure composed of AlInGaN, wherein the content of Al in the single structure composed of AlInGaN is 0.5% to 30%.

[0020] For example, in some embodiments of the first aspect of the present disclosure, the insertion layer comprises a superlattice structure composed of AlGaN material and GaN material, wherein the content of Al in the superlattice structure is 0.5% to 30%.

[0021] For example, in some embodiments of the first aspect of the present disclosure, the insertion layer comprises a superlattice structure composed of AlInGaN material and GaN material, wherein the content of Al in the superlattice structure is 0.5% to 30%.

[0022] For example, in some embodiments of the first aspect of the present disclosure, the content of Al in the insertion layer gradually decreases in the direction from the first film layer to the second film layer. The multi-quantum well structure in this scheme can realize the function of emitting light with shorter electroluminescent wavelength.

[0023] For example, in some embodiments of the first aspect of the present disclosure, the thickness of the insertion layer is 0.2nm to 5nm.

[0024] For example, in some embodiments of the first aspect of the present disclosure, the insertion layer is a single-layer structure composed of a single structure or a superlattice structure.

[0025] For example, in some embodiments of the first aspect of the present disclosure, the insertion layer is a multi-layer structure composed of a single structure and / or a superlattice structure. In this way, the light-emitting efficiency of the multi-quantum well can be improved.

[0026] For example, in some embodiments of the first aspect of the present disclosure, the insertion layer is n-type doped or p-type doped.

[0027] For example, in the multi-quantum well structure provided by the first aspect of the present disclosure, the at least one stack is multiple and stacked with each other.

[0028] The second aspect of the present disclosure provides a light emitting diode comprising the multi-quantum well structure of any of the embodiments of the first aspect.

[0029] For example, the light emitting diode provided by the second aspect of the present disclosure further comprises a substrate, an N-type layer and a P-type layer. The N-type layer is located on the substrate, and the P-type layer is located on the side of the N-type layer away from the substrate. The multi-quantum well structure is located between the N-type layer and the P-type layer, and in the direction from the N-type layer to the P-type layer, the first film layer, the insertion layer and the second film layer in each stack are arranged in sequence.

[0030] The third aspect of the present disclosure provides a light emitting assembly comprising at least one first light emitting diode emitting first color light and at least one second light emitting diode emitting second color light. The wavelength of the first color light is smaller than the wavelength of the second color light, and the second light emitting diode is the light emitting diode of the embodiments of the second aspect. For example, in some embodiments of the third aspect of the present disclosure, the first color light can be blue light or green light, and the second color light can be yellow light or red light. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present disclosure, and other drawings can also be obtained by those skilled in the art without creative labor.

[0032] Figure 1 A cross-sectional schematic view of a multi-quantum well structure provided by an embodiment of the present disclosure;

[0033] Figure 2 A cross-sectional schematic view of another multi-quantum well structure provided by an embodiment of the present disclosure;

[0034] Figure 3 A cross-sectional schematic view of a light emitting diode provided by an embodiment of the present disclosure;

[0035] Figure 4 A planar structure schematic view of a light emitting assembly provided by an embodiment of the present disclosure;

[0036] Figure 5 A cross-sectional view of the light emitting assembly shown along M-N; Figure 4

[0037] Figure 6 ​Another schematic diagram of a planar structure of a light emitting component is provided for an embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0039] In the process of manufacturing the light emitting film layer (for example, the potential well layer) in the multi-quantum well by means of low epitaxial temperature, due to the low epitaxial temperature, the unintentional doping caused by impurities such as C element is high in the process of epitaxially growing the potential well layer, and the low temperature causes the lateral epitaxial rate of the potential well layer to be small, which promotes the formation of point and line dislocations, and V-shaped pits may be formed as the epitaxial growth continues, thereby causing defects in the film layer in the multi-quantum well. In view of this, the embodiments of the present disclosure relate to a multi-quantum well structure, a light emitting diode and a light emitting component, which can solve the above technical problems.

[0040] The embodiments of the present disclosure provide a multi-quantum well structure, which includes at least one stack composed of a first film layer, an interposed layer and a second film layer. The interposed layer is located between the first film layer and the second film layer. The interposed layer includes a single structure and / or a superlattice structure. The first film layer includes In, Ga and N, the interposed layer includes Al, Ga and N, and the second film layer includes Ga and N. In this way, the interposed layer including Al, Ga and N is different from the first film layer including In, Ga and N in terms of the band gap and the lattice constant, which causes a strong built-in electric field to be formed in the first film layer, and under the condition of a forward bias, the actual conduction band level of the first film layer is bent downward and the band gap is narrowed, so that the first film layer can excite light of a longer wavelength compared with the case where the interposed layer is not arranged, and in this process, the first film layer does not need to be grown by low-temperature epitaxy, thereby preventing defects and other adverse effects caused by growing the first film layer by low-temperature epitaxy.

[0041] Next, the multi-quantum well structure, the light emitting diode and the light emitting component according to at least one embodiment of the present disclosure will be described in detail with reference to the drawings. In the drawings, a spatial rectangular coordinate system is established with reference to the plane where the first film layer is located, so as to directionally describe the positions of various film layers in the multi-quantum well structure, the light emitting diode and the light emitting component. In the spatial rectangular coordinate system, the X-axis and the Y-axis are parallel to the plane where the first film layer is located, and the Z-axis is perpendicular to the plane where the first film layer is located.

[0042] In the embodiments of the present disclosure, as shown in FIG. 1, the multi-quantum well structure includes at least one stack composed of a first film layer 11, an interposed layer 12 and a second film layer 13. Figure 1As shown, the multi-quantum well structure includes a stack 100, which includes a first film layer 111, an interposed layer 112 and a second film layer 113 stacked in sequence. The first film layer 111 includes elements In, Ga and N, for example, the first film layer 111 includes material InGaN; the interposed layer 112 includes elements Al, Ga and N, for example, the interposed layer 112 includes material AlGaN; and the second film layer 113 includes elements Ga and N, for example, the second film layer 113 includes material GaN. The interposed layer 112 includes a single structure and / or a superlattice structure, both of which include elements Al, Ga and N. For example, the interposed layer 112 can be composed of a single structure and / or a superlattice structure.

[0043] For example, in embodiments of the present disclosure, as Figure 1 As shown, the first film layer 111 is a potential well layer, the second film layer 113 is a potential barrier layer, and the interposed layer 112 is an interposed layer. In the process of producing the stack 100, after the first film layer 111 is formed, the interposed layer 112 is grown on the first film layer 111, and then the second film layer 113 is grown on the interposed layer 112.

[0044] In addition, for the stack 100 as Figure 1 As shown, without the second film 112, the first film layer 111 and the second film layer 113 are in contact, but the lattice size of the first film layer 111 including In, Ga and N and the second film layer 113 including Ga and N is quite different, resulting in poor crystal quality of the stack 100 and causing the well bias effect to be extremely low, or even the stack 100 cannot effectively emit light. As Figure 1 After the interposed layer 112 is inserted between the first film layer 111 and the second film layer 113, the lattice difference between the first film layer 111 and the interposed layer 112 and between the interposed layer 112 and the second film layer 113 is small, thereby improving the crystal quality of the stack 100.

[0045] In embodiments of the present disclosure, the interposed layer can include elements Al, Ga and N, and on this basis, the specific material formed by elements Al, Ga and N in the interposed layer is not limited, and whether the interposed layer includes other elements to form other materials is also not limited, and can be selected according to the actual process needs. For example, in some embodiments, Al, Ga and N of the interposed layer can be used only to form AlGaN. For example, in other embodiments, Al, Ga and N of the interposed layer can be used to form AlGaN and GaN. For example, in other embodiments, other elements can be doped in the interposed layer to form other types of materials in addition to AlGaN and GaN with elements Al, Ga and N, for example, the other elements can be In, etc. In the following, through several specific examples, multi-quantum well structures with several different types of interposed layers are described.

[0046] For example, in some embodiments of the present disclosure, the insertion layer only includes Al, Ga and N, and Al, Ga and N are formed into AlGaN, i.e., the insertion layer is a single AlGaN material layer.

[0047] For example, in some other embodiments of the present disclosure, the insertion layer only includes Al, Ga and N, and Al, Ga and N are used to form GaN material and AlGaN material, and the GaN material and the AlGaN material are formed into a superlattice structure. In this way, the GaN and the AlGaN in the insertion layer can form a superlattice structure (SLs), which is a periodic structure, and the conduction band and the valence band energy levels corresponding thereto are also periodic. In the doping process, the conduction band or the valence band energy level corresponding to this structure will overlap with the uniform Fermi level, which is conducive to improving the carrier concentration, thereby providing better carrier injection efficiency and improving the overall light-emitting efficiency of the multi-quantum well structure.

[0048] For example, in some embodiments of the present disclosure, in the case where the insertion layer includes AlGaN, the composition content of Al in the AlGaN material gradually increases in the direction from the first film layer to the second film layer. In this way, the multi-quantum well structure can realize the function of emitting light with a longer electroluminescent wavelength. In this case, as the injection current increases, the blue shift of the light-emitting wavelength is less. Alternatively, the composition content of Al in the AlGaN material gradually decreases. In this way, the multi-quantum well structure can realize the function of emitting light with a shorter electroluminescent wavelength. In this case, as the injection current increases, the blue shift of the light-emitting wavelength is more. In this embodiment, the "composition content" is the percentage of the number of atoms in the material.

[0049] For example, in some embodiments of the present disclosure, in the case where the insertion layer includes AlGaN, the composition content of Al in the AlGaN material is 0.2% to 50%, and further is 0.5% to 30%.

[0050] For example, in some other embodiments of the present disclosure, the insertion layer further includes In, and the insertion layer further includes InAlGaN material. For example, the insertion layer includes GaN material and InAlGaN material, and the GaN material and the InAlGaN material can be formed into a superlattice structure. In this way, by incorporating In in the insertion layer, the generation of point defects when epitaxially growing the insertion layer (e.g., the AlGaN material included therein) and the stress between the film layers can be suppressed, thereby further improving the quality, light-emitting efficiency of the multi-quantum well structure and suppressing the separation and precipitation of In (e.g., In in the potential well layer).

[0051] For example, in the multi-quantum well structure provided by some embodiments of the present disclosure, the insertion layer comprises a single structure composed of AlGaN, and the composition ratio of Al in the single structure composed of AlGaN is 0.5% to 30%. For example, the composition ratio of Al gradually changes within the range of 0.5% to 30%.

[0052] For example, in the multi-quantum well structure provided by some embodiments of the present disclosure, the insertion layer comprises a single structure composed of AlGaN, and the composition ratio of Al in the single structure composed of AlGaN is 0.5% to 30%. For example, the composition ratio of Al gradually changes within the range of 0.5% to 30%.

[0053] For example, in the multi-quantum well structure provided by some embodiments of the present disclosure, the insertion layer comprises a single structure composed of AlGaN, and the composition ratio of Al in the single structure composed of AlGaN is 0.5% to 30%. For example, the composition ratio of Al gradually changes within the range of 0.5% to 30%.

[0054] For example, in the multi-quantum well structure provided by some embodiments of the present disclosure, the insertion layer comprises a single structure composed of AlGaN, and the composition ratio of Al in the single structure composed of AlGaN is 0.5% to 30%. For example, the composition ratio of Al gradually changes within the range of 0.5% to 30%.

[0055] In the case where the insertion layer is not provided, the thickness of the first film layer is usually between 1 and 4 nm, and the thickness of the second film layer is usually between 3 and 20 nm. In the embodiments of the present disclosure, in the case where the composition content of Al in the insertion layer is gradually changed (gradually increased or decreased) and / or the insertion layer is provided in the superlattice structure, the thickness of the insertion layer can be between 0.2 nm and 5 nm.

[0056] For example, in the multi-quantum well structure provided by some embodiments of the present disclosure, the insertion layer is a single layer structure composed of a single structure or a superlattice structure. For example, the insertion layer is a film layer composed of AlGaN or AlInGaN.

[0057] For example, in some other embodiments of the multi-quantum-well structure provided in this disclosure, the intercalation layer is a multilayer structure composed of a monomer structure and / or a superlattice structure. For example, the intercalation layer may be multiple films composed of AlGaN, or multiple films composed of AlInGaN, or films composed of both AlGaN and AlInGaN. This improves the luminous efficiency of the multi-quantum-well. For example, when the intercalation layer includes both AlGaN and AlInGaN films, multiple AlGaN and AlInGaN films can be stacked alternately on top of each other. This further improves the luminous efficiency of the multi-quantum-well.

[0058] For example, in the multi-quantum-well structure provided in the embodiments of this disclosure, at least one stacked layer is multiple and stacked on top of each other. For example, as... Figure 2 As shown, multiple stacks 100 are stacked on top of each other. For example, a multi-quantum-well structure may include at least 10 stacks, with different stacks stacked on top of each other. For example, further, a multi-quantum-well structure may include at least 20 stacks.

[0059] For example, in the multi-quantum-well structure provided in the embodiments of this disclosure, the insertion layer can be n-type doped or p-type doped, thereby improving the luminescence efficiency of the multi-quantum-well structure.

[0060] Embodiments of this invention provide a light-emitting diode (LED) comprising the multi-quantum-well structure described in any of the above embodiments.

[0061] For example, in the light-emitting diodes provided in the embodiments of this disclosure, such as Figure 3 As shown, the light-emitting diode includes a multi-quantum-well structure 10, a substrate 20, an N-type layer 40, and a P-type layer 50. The N-type layer 40, the multi-quantum-well structure 10, and the P-type layer 50 are sequentially stacked on the substrate 20. From the N-type layer 40 to the P-type layer 50, a first film layer, an insertion layer, and a second film layer are sequentially arranged in each stack. The N-type layer 40 can be an N-type GaN film, and the P-type layer 50 can be a P-type GaN film.

[0062] For example, the substrate 20 can be a sapphire substrate, a GaN-based substrate, a Si-based substrate, a SiN-based substrate, or a glass substrate, etc.

[0063] For example, in the light emitting diode provided by the embodiments of the present disclosure, a plurality of recesses can be arranged in the N-type layer, and a DBR (Distributed Bragg Reflector mirror) structure and / or a photonic crystal structure can be arranged in the recesses. The DBR structure and / or the photonic crystal structure can be used to filter light rays of a specific wavelength range, thereby improving the monochromaticity of the light rays emitted by the light emitting diode. The DBR structure is composed of at least two semiconductor materials or dielectric materials grown alternately, and the DBR structure can be used to obtain high reflectivity for waves of a certain frequency range (equivalent to light rays in a certain wavelength range). The photonic crystal is a periodic dielectric structure with a photonic band gap (PBG) characteristic, and in this periodic structure, waves of a certain frequency range cannot propagate.

[0064] For example, in the light emitting diode provided by the embodiments of the present disclosure, the light emitting diode can further include a u-shaped layer. For example, as shown in FIG. 3, the u-shaped layer 30 is located between the N-type layer 40 and the substrate 20. For example, the u-shaped layer 30 can be a u-shaped GaN film layer. Figure 3

[0065] For example, in the embodiments of the present disclosure, the light emitting diode can further include a buffer layer located between the substrate and the N-type layer 40. For example, the buffer layer can include one or a combination of AlN, GaN, AlGaN, and InGaN. The buffer layer can greatly relieve the stress generated when growing the epitaxial layer on the silicon substrate, and achieve dislocation filtering, thereby improving the crystal quality of the epitaxial layer. For example, the buffer layer can also act as a planarization layer. When the buffer layer is formed on the substrate, the surface of the light emitting diode including the substrate is subjected to planarization processing, thereby improving the planarization of the film layers in the N-type layer, the multi-quantum well structure, and the P-type layer prepared subsequently, and ensuring the preparation yield of the light emitting diode.

[0066] The embodiments of the present disclosure provide a light emitting assembly including at least one first light emitting diode emitting first color light rays and at least one second light emitting diode emitting second color light rays. The wavelength of the first color light rays is smaller than the wavelength of the second color light rays, and the second light emitting diode is the light emitting diode in the embodiments of the second aspect. For example, the first color light rays can be blue light or green light, and the second color light rays can be yellow light or red light. For example, the light emitting assembly can include light emitting diodes emitting multiple colors of light rays, and the light emitting diodes emitting different colors and adjacent to each other are combined into a unit. In this way, the unit can emit white light, colored light, or other color light rays as needed. For example, further, the light emitting assembly can be used in the display field, and the unit can be used as a display unit (equivalent to a pixel) for displaying images.

[0067] ​For example, in an embodiment of the present disclosure, the light emitting assembly can be a display panel. As an example, as shown in Figure 4 and Figure 5 the light emitting assembly includes three types of light emitting diodes 1, 2, 3, which are arranged to emit light of three colors (e.g. red, green, blue) respectively, and adjacent light emitting diodes 1, 2, 3 form a display unit (pixel), and the light emitting diodes 1, 2, 3 are sub-pixels respectively.

[0068] For example, in an embodiment of the present disclosure, the planar area of the first light emitting diode is smaller than that of the second light emitting diode. As an example, the display unit of the light emitting assembly includes light emitting diodes 1, 2, 3 emitting light of three colors (red, green, blue) respectively, and the design area of the light emitting diode 1 is larger than that of the light emitting diodes 2 and 3. The light emitting diode emitting long-wavelength light (e.g. red light) has limited ability, and increasing the current intensity will cause light emission blue shift. Designing the planar area of the light emitting diode emitting long-wavelength light to be larger can ensure the brightness of the long-wavelength light while reducing the requirement for current intensity and the degree of light emission blue shift.

[0069] It should be noted that in an embodiment of the present disclosure, the number of light emitting diodes (the number of colors of emitted light) included in each display unit of the light emitting assembly and the arrangement of the plurality of light emitting diodes are not limited. For example, as shown in Figure 5 the light emitting diodes 1, 2, 3 in each display unit are arranged in a row / column; or as shown in Figure 6 the light emitting diodes 1, 2, 3 in each display unit are arranged in a triangular shape.

[0070] In an embodiment of the present disclosure, the light emitting assembly (display panel) can be used in the field of AR or VR display. As an example, the light emitting assembly is used in AR glasses, which include a light waveguide lens and an optical assembly, and the light emitted by the light emitting assembly (equivalent to a displayed image) is incident into the light waveguide lens after passing through the optical assembly (e.g. including a magnifying glass, etc.), and then the light is guided into the human eye by the light waveguide lens, while the human eye can observe the image of the surrounding environment through the light waveguide lens, so that the displayed image observed by the human eye is projected in the environmental image, realizing augmented reality display. In an embodiment of the present disclosure, for the light emitting diode emitting long-wavelength light such as red light, after using the multi-quantum well structure in the above-mentioned embodiment of the present disclosure, the blue shift phenomenon during light emission is reduced or the degree of blue shift is low, thereby improving the display effect of the light emitting assembly.

[0071] The above only describes the preferred embodiments of the present disclosure and is not intended to limit the present disclosure. Any modification, equivalent replacement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A multiple quantum well structure, characterized by, The at least one stack comprises a first film layer, an interposed layer and a second film layer, the at least one stack is multiple and stacked with each other, and the interposed layer is located between the first film layer and the second film layer; The interposed layer comprises a single structure and / or a superlattice structure, the first film layer comprises In, Ga and N, the interposed layer comprises Al, Ga and N, and the second film layer comprises Ga and N; in the direction from the first film layer to the second film layer, the component content of Al in the interposed layer gradually increases to emit light with longer electroluminescent wavelength or gradually decreases to emit light with shorter electroluminescent wavelength; The lattice difference between the first film layer and the interposed layer and the lattice difference between the interposed layer and the second film layer are smaller than the lattice difference between the first film layer and the second film layer, and the band gap of the interposed layer is larger than the band gap of the first film layer and the second film layer.

2. The multiple quantum well structure of claim 1, wherein, The interposed layer is AlGaN material and / or AlInGaN.

3. The multi-quantum well structure of claim 1, wherein: The interposed layer comprises the single structure of AlGaN, and the component content of Al in the single structure of AlGaN is 0.5% to 30%; or The interposed layer comprises the single structure of AlInGaN, and the component content of Al in the single structure of AlInGaN is 0.5% to 30%; or The interposed layer comprises the superlattice structure of AlGaN material and GaN material, and the component content of Al in the superlattice structure is 0.5% to 30%; or The interposed layer comprises the superlattice structure of AlInGaN material and GaN material, and the component content of Al in the superlattice structure is 0.5% to 30%.

4. The multiple quantum well structure of claim 1, wherein, The thickness of the interposed layer is 0.2 nm to 5 nm.

5. The multi-quantum well structure of claim 1, wherein: The interposed layer is a single-layer structure composed of the single structure or the superlattice structure; and / or The interposed layer is a multi-layer structure composed of the single structure and / or the superlattice structure.

6. The multiple quantum well structure of claim 1, wherein, The interposed layer is n-type doped or p-type doped.

7. The multiple quantum well structure of claim 1, wherein, The band gap of the interposed layer is larger than the band gap of the first film layer and the second film layer.

8. A light-emitting diode, comprising the multi-quantum well structure of any one of claims 1-7.

9. The light-emitting diode of claim 8, further comprising: a substrate; an N-type layer located on the substrate; a P-type layer located on the side of the N-type layer away from the substrate; The multi-quantum well structure is located between the N-type layer and the P-type layer, and the first film layer, the interposed layer and the second film layer in each stack are arranged in sequence from the direction of the N-type layer to the P-type layer.

10. A light emitting assembly characterized by The light-emitting diode comprises at least one first light-emitting diode emitting light of a first color and at least one second light-emitting diode emitting light of a second color, wherein The wavelength of the first color light is less than the wavelength of the second color light, and the second light emitting diode is the light emitting diode as defined in claim 8 or 9.

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