Light-emitting chip epitaxial layer, manufacturing method and light-emitting chip

Abstract

The invention relates to a light-emitting chip epitaxial layer, a manufacturing method and a light-emitting chip. The light-emitting chip epitaxial layer comprises a first semiconductor layer; the active layer is arranged on the first semiconductor layer; the second semiconductor layer is arranged on one side, far away from the first semiconductor layer, of the active layer; wherein the first semiconductor layer is an N-type semiconductor layer or a P-type semiconductor layer, and the conduction type of the second semiconductor layer is different from that of the first semiconductor layer; the active layer is configured to have a quantum-limited stark effect, and the quantum-limited stark effect causes emission wavelengths of the active layer at different currents to have a wavelength shift of more than 60 nanometers. The bicolor light emitting based on the epitaxial layer of the light-emitting chip can be realized only by providing different currents, so that the manufacturing of a bicolor integrated display product is simpler.

Description

Technical Field

[0001] This application relates to the field of LEDs, and particularly to an epitaxial layer of a light-emitting chip, a manufacturing method thereof, and a light-emitting chip. Background Art

[0002] With the development of display technologies, existing LCDs (Liquid Crystal Displays) and OLEDs (Organic Light-Emitting Diodes) are gradually unable to meet higher performance requirements. Display products based on MicroLEDs (Micro Light Emitting Diodes) are expected to be widely used in near-eye display fields such as VR (Virtual Reality) and AR (Augmented Reality). However, the solutions for dual-color MicroLEDs mainly include fabricating MicroLEDs of different colors using materials with different compositions and then setting them on a display panel through a mass transfer method; or performing color conversion on monochromatic MicroLEDs. These dual-color display solutions all require one or more monochromatic MicroLED chips, and the manufacturing process of the display products is complex, and it is impossible to simply implement a dual-color integrated MicroLED chip.

[0003] Therefore, how to simply achieve dual-color integration based on a single epitaxial layer is an urgent problem to be solved. Summary of the Invention

[0004] In view of the deficiencies of the above-mentioned related technologies, the purpose of this application is to provide an epitaxial layer of a light-emitting chip, a manufacturing method thereof, and a light-emitting chip, aiming to solve the problem that dual-color display solutions require one or more monochromatic MicroLED chips, and the manufacturing process of display products is complex, and it is impossible to simply implement a dual-color integrated MicroLED chip.

[0005] An epitaxial layer of a light-emitting chip includes:

[0006] A first semiconductor layer;

[0007] An active layer disposed on the first semiconductor layer; and

[0008] A second semiconductor layer disposed on a side of the active layer away from the first semiconductor layer;

[0009] Wherein, the first semiconductor layer is an N-type semiconductor layer or a P-type semiconductor layer, and the second semiconductor layer has a different conduction type from the first semiconductor layer; the active layer is configured to have a quantum-confined Stark effect, and the quantum-confined Stark effect causes the emission wavelength of the active layer to have a wavelength shift of more than 60 nanometers at different currents.

[0010] For the above-mentioned light-emitting chip epitaxial layer, through the design of the quantum-confined Stark effect of the active layer, the active layer has a wavelength shift of more than 60 nanometers at different currents, so that a single light-emitting chip epitaxial layer can emit two kinds of light with significantly different visual effects. Therefore, by simply providing different currents, dual-color emission based on the light-emitting chip epitaxial layer can be achieved, which makes the production of dual-color integrated display products simpler in some implementation processes.

[0011] Optionally, the N-type semiconductor layer includes not less than 10 Stark effect enhancement layers, and the Stark effect enhancement layers are configured to reduce the kinetic energy of electrons.

[0012] Multiple Stark effect enhancement layers reduce the kinetic energy of electrons, which can reduce the migration rate of electrons, reduce the electrons overflowing from the active layer, and make the region where the wave functions of electron-hole pairs coincide larger, thereby enhancing the quantum-confined Stark effect in the active region.

[0013] Optionally, each Stark effect enhancement layer includes a first GaN sublayer, a first AlGaN sublayer, an AlN sublayer, a second AlGaN sublayer, and a second GaN sublayer arranged in sequence.

[0014] In the Stark effect enhancement layer, the potential energy of each sublayer changes repeatedly between high and low, causing electrons to move repeatedly from low potential to high potential when passing through the Stark effect enhancement layer, thereby effectively reducing the kinetic energy of electrons.

[0015] Optionally, the active layer includes alternately arranged quantum barrier layers and quantum well layers, and the setting period of the quantum barrier layers and the quantum well layers is not less than 15.

[0016] Increasing the number of periods of the active layer will, in some implementation processes, make the region where the wave functions of electron-hole pairs coincide in the active layer larger, not only concentrated in the last one or two quantum well layers. Therefore, at different currents, different energy band recombination positions can be achieved, with a stronger quantum-confined Stark effect.

[0017] Optionally, the quantum barrier layer includes GaN, the quantum well layer includes InGaN, the active layer is configured to have an emission wavelength corresponding to green, and as the current increases, the emission wavelength shifts to the emission wavelength corresponding to blue.

[0018] The In content of the green light-emitting chip is relatively high, and the stress between the GaN quantum barrier layer and the InGaN quantum well layer is relatively large, further enhancing the quantum-confined Stark effect, resulting in a relatively obvious blue shift of the wavelength; it is relatively easy to achieve a relatively large range of blue shift of the wavelength, achieving the effect of dual-color emission.

[0019] Optionally, the N-type semiconductor layer further includes a stress relaxation layer adjacent to the active layer, and / or, the P-type semiconductor layer further includes a hole-accumulating layer disposed on the active layer.

[0020] Structures such as the stress relaxation layer and the hole-accumulating layer also ensure the quality of the epitaxial layer of the light-emitting chip during fabrication, and also have a positive effect on achieving a strong quantum-confined Stark effect.

[0021] Based on the same inventive concept, the present application also provides a method for fabricating an epitaxial layer of a light-emitting chip, including:

[0022] Providing a first semiconductor layer on a substrate;

[0023] Providing an active layer on the first semiconductor layer; and

[0024] Providing a second semiconductor layer on the active layer;

[0025] Wherein, the first semiconductor layer is an N-type semiconductor layer or a P-type semiconductor layer, and the second semiconductor layer has a different conductivity type from the first semiconductor layer; the active layer is configured to have a quantum-confined Stark effect, and the quantum-confined Stark effect causes the emission wavelength of the active layer to have a wavelength shift of more than 60 nanometers under different currents.

[0026] For the epitaxial layer of the light-emitting chip fabricated by the above method for fabricating an epitaxial layer of a light-emitting chip, its active layer has a wavelength shift of more than 60 nanometers under different currents, so that a single epitaxial layer of a light-emitting chip can emit two kinds of light with significantly different visual effects. Therefore, by simply providing different currents, dual-color emission based on the epitaxial layer of the light-emitting chip can be achieved, making the fabrication of dual-color integrated display products simpler in some implementation processes.

[0027] Based on the same inventive concept, the present application also provides a light-emitting chip, including:

[0028] The above-mentioned epitaxial layer of the light-emitting chip;

[0029] A first electrode connected to the first semiconductor layer; and

[0030] A second electrode connected to the second semiconductor layer.

[0031] The above-mentioned light-emitting chip adopts the foregoing epitaxial layer of the light-emitting chip. Its active layer has a wavelength shift of more than 60 nanometers under different currents, and can have different light-emitting wavelengths based on different currents, and can be well applied in dual-color display products. Description of the Drawings

[0032] Figure 1 Schematic diagram of the basic structure of the epitaxial layer of the light-emitting chip provided by an embodiment of the present application;

[0033] Figure 2 Schematic diagram of the active layer structure of the epitaxial layer of the light-emitting chip provided by an embodiment of the present application;

[0034] Figure 3 Another schematic diagram of the epitaxial layer of the light-emitting chip provided by an embodiment of the present application;

[0035] Figure 4 Schematic diagram of a structure of the Stark effect enhancement layer provided by an embodiment of the present application;

[0036] Figure 5 Schematic diagram of the structural characteristics of the Stark effect enhancement layer provided by an embodiment of the present application;

[0037] Figure 6 Schematic diagram of a structure of the light-emitting chip provided by an embodiment of the present application;

[0038] Figure 7 Schematic diagram of the process of the manufacturing method of the epitaxial layer of the light-emitting chip provided by an embodiment of the present application;

[0039] Figure 8 Schematic diagram of the process of setting the Stark effect enhancement layers of each layer provided by an embodiment of the present application;

[0040] Figure 9 Schematic diagram of the manufacturing process of an exemplary epitaxial layer of the light-emitting chip provided by an embodiment of the present application;

[0041] Figure 10 Schematic diagram of a structure of a stress release layer provided by an embodiment of the present application;

[0042] Description of the Reference Numerals:

[0043] 1 - First semiconductor layer; 11 - Stark effect enhancement layer; 111 - First GaN sublayer; 112 - First AlGaN sublayer; 113 - AlN sublayer; 114 - Second AlGaN sublayer; 115 - Second GaN sublayer; 12 - GaN buffer layer; 13 - N-type doped GaN layer; 14 - Low-doped GaN layer; 15 - Stress release layer; 151 - In x Ga 1-xN-layer; 152-GaN layer; 2-active layer; 21-quantum barrier layer; 22-quantum well layer; 3-second semiconductor layer; 31-hole accumulation layer; 32-P-type doped GaN layer; 41-N-type electrode; 42-P-type electrode; 5-substrate. Detailed implementation mode

[0044] For the convenience of understanding the present application, the present application will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0046] The dual-color display solutions in the related art need to be based on one or more monochromatic Micro LED chips, and the manufacturing process of the display product is complex, and it is impossible to simply implement a dual-color integrated Micro LED chip. Based on this, the present application hopes to provide a solution that can solve the above technical problems, and its detailed content will be elaborated in the subsequent embodiments.

[0047] Embodiment:

[0048] This embodiment provides a light-emitting chip epitaxial layer. Refer to Figure 1 As shown, the light-emitting chip epitaxial layer includes a first semiconductor layer 1, an active layer 2, and a second semiconductor layer 3. Among them, the first semiconductor layer 1 is an N-type semiconductor layer or a P-type semiconductor layer, and the second semiconductor layer 3 has a different conductivity type from the first semiconductor layer 1; that is, if the first semiconductor layer 1 is an N-type semiconductor layer, then the second semiconductor layer 3 is a P-type semiconductor layer, and vice versa.

[0049] The material of the light-emitting chip epitaxial layer can be selected from III / V group semiconductor materials including but not limited to Al (aluminum), Ga (gallium), In (indium), and P (phosphorus), As (arsenic), or N (nitrogen), etc. Usually, it can include, for example, GaN (gallium nitride) - based materials, AlGaInP (aluminum gallium indium phosphide) - based materials, GaAs (gallium arsenide) - based materials, and so on. In practical applications, the light-emitting chip epitaxial layer can be grown on a substrate 5, and the material of the substrate 5 includes but not limited to Al2O3 (aluminum oxide, that is, sapphire), SiC (silicon carbide), Si (silicon), GaN, and can also be other semiconductor materials; the substrate material with better lattice matching can be selected according to the material of the light-emitting chip epitaxial layer.

[0050] In this application, the N-type semiconductor layer and the P-type semiconductor layer only represent the distinction of the conduction type. Specifically, in the epitaxial layer of the light-emitting chip, the N-type semiconductor layer includes an N-type doping source, and the P-type semiconductor layer includes a P-type doping source. For example, Si can be used as the N-type doping source for GaN materials, and Mg (magnesium) can be used as the P-type doping source for GaN materials, but it is not limited thereto. The N-type semiconductor layer is used to provide electrons, and the P-type semiconductor layer is used to provide holes. The electrons and holes move to the active region for effective recombination, thereby achieving light emission. When growing the epitaxial layer of the light-emitting chip, the N-type semiconductor layer can be grown first. In some examples, the P-type semiconductor layer can also be grown first, which can be specifically set according to actual needs, and this embodiment does not limit it.

[0051] The active layer 2 can be a multi-quantum well active layer or a superlattice active layer. The active layer 2 includes a plurality of quantum barrier layers 21 and a plurality of quantum well layers 22 arranged alternately. In this embodiment, the active layer 2 has a quantum-confined Stark effect, and the quantum-confined Stark effect causes the emission wavelength of the active layer 2 to have a wavelength shift of more than 60 nanometers at different currents. It can be understood that affected by the quantum-confined Stark effect, as the injection current increases, the emission wavelength of the active layer 2 will undergo a blue shift phenomenon, that is, the emission wavelength at high current is shorter than that at low current. Conventional epitaxial layers of light-emitting chips usually control the wavelength shift range caused by the quantum-confined Stark effect within a few nanometers or a dozen nanometers. In some applications, the quantum-confined Stark effect is also suppressed by structural or material settings to keep the emission wavelength of the light-emitting chip stable. In actual applications, in order to avoid the drift of the emission wavelength, in some applications, pulse width modulation is also used to adjust the brightness to avoid color inconsistency at different brightness levels caused by changing the current intensity.

[0052] However, in this embodiment, the influence range of the quantum-confined Stark effect of the active layer 2 is controlled to exceed 60 nanometers. That is, in this embodiment, not only is the quantum-confined Stark effect not suppressed, but in some implementation processes, in order to ensure that its emission wavelength has a large range of movement, the influence brought by the quantum-confined Stark effect can also be enhanced.

[0053] Different from traditional display solutions, it is necessary to transfer light-emitting chips of different colors formed on different epitaxies respectively, or to fabricate complex structures such as color conversion layers on monochromatic light-emitting chips. In this embodiment, through the design of the quantum-confined Stark effect of the active layer 2, the active layer 2 has a wavelength shift of more than 60 nanometers under different currents, so that a single light-emitting chip epitaxial layer can emit two kinds of light with significantly different visual effects. Therefore, by simply providing different currents, dual-color emission based on the light-emitting chip epitaxial layer can be achieved, which makes the production of dual-color integrated display products simpler in some implementation processes. In some implementation processes, the number of transfers required is reduced, which is beneficial to production efficiency and yield; in some implementation processes, the number of settings of the color conversion layer is reduced, simplifying the manufacturing process.

[0054] In fact, in the process of fabricating a light-emitting chip from a light-emitting chip epitaxial layer, the overall resistance of the light-emitting chip can be controlled to control the current magnitude under a specific driving voltage, so as to obtain the required emission color; or different driving voltages can be directly supplied to different light-emitting chips during driving, so that the light-emitting chips formed by the same light-emitting chip epitaxial layer produce different emission colors.

[0055] As Figure 2 shown, the active layer 2 includes a plurality of quantum well layers 22 and a plurality of quantum barrier layers 21 arranged alternately. However, in practical applications, the region where effective recombination of electrons and holes occurs is mainly concentrated in the last one or two quantum well layers 22 close to the P-type semiconductor layer. As the current increases, although the active layer 2 undergoes a certain degree of blue shift under the influence of the quantum-confined Stark effect, electrons are likely to overflow the active layer 2, forming ineffective current injection and a rapid decline in light efficiency. Therefore, in some applications, the blue shift range of the active layer 2 can be limited to a few nanometers or a dozen nanometers.

[0056] In practical applications, various means can be used to make the light-emitting chip epitaxial layer have a strong quantum-confined Stark effect (that is, having a large range of wavelength shift under the influence of the quantum-confined Stark effect). As long as the light-emitting chip epitaxial layer can have a wavelength shift of more than 60 nanometers, it is feasible. Of course, the 60-nanometer wavelength shift should occur within the normal operating current range of the light-emitting chip, that is, it is not destructive, in order to achieve normal application display. For different processes or materials, the specific operating current range will vary, and this application does not specifically limit it.

[0057] In some implementation processes, the quantum-confined Stark effect of the active layer 2 can be enhanced by making the region where the wave functions of electron-hole pairs overlap larger. As an example, the number of periods of the active layer 2 can be increased, which will make the region where the wave functions of electron-hole pairs overlap in the active layer 2 larger, no longer only concentrated in the last one or two quantum well layers 22. Thus, at different currents, recombination positions of different energy bands can be achieved. For example, the wave functions of electron-hole pairs can overlap well in the last 4 - 5 quantum well layers 22. Also, for example, the structure outside the active layer 2 can be designed to make the region where the wave functions of electron-hole pairs overlap larger, such as reducing the kinetic energy of electrons or accelerating the migration rate of holes. In practical applications, various means can also be comprehensively used to make the emission wavelength of the active layer 2 have a wavelength shift of more than 60 nm at different currents. Also, for example, by controlling the stress distribution in the active layer 2, stronger stress can enhance the quantum-confined Stark effect of the active layer 2; in practical applications, on the premise of balancing various performances, the stress in the active layer 2 can be increased to a certain extent.

[0058] It should also be noted that in practical applications, to ensure the performance in other aspects, the light-emitting chip epitaxial layer can also include structures that will inhibit the quantum-confined Stark effect, as long as it is ensured that the light-emitting chip epitaxial layer can finally have a wavelength shift of more than 60 nm in the emission wavelength at different currents.

[0059] As Figure 3 As shown, in some embodiments, the N-type semiconductor layer includes multiple Stark effect enhancement layers 11, and the Stark effect enhancement layer 11 is configured to reduce the kinetic energy of electrons. For ease of explanation, in this embodiment, the first semiconductor layer 1 is taken as an example of the N-type semiconductor layer, but in other examples, the N-type semiconductor layer can also be the second semiconductor layer 3. In semiconductor materials such as GaN, the migration rate of electrons is usually dozens or even hundreds of times higher than that of holes, and electrons may migrate out of the active layer 2 before they are effectively recombined with holes. To enhance the influence of the quantum-confined Stark effect on the active layer 2, the Stark effect enhancement layer 11 that can reduce the kinetic energy of electrons is provided in the N-type semiconductor layer, which can reduce the migration rate of electrons, reduce the electrons overflowing from the active layer 2, make the region where the wave functions of electron-hole pairs overlap larger, and thus improve the quantum-confined Stark effect of the active region. On the other hand, the active layer 2 of the present application has a wavelength shift of more than 60 nm at different currents. As the injection current increases, electrons are more likely to overflow from the active layer 2. The Stark effect enhancement layer 11 reduces the kinetic energy of electrons to reduce their overflow, making the light efficiency of the active layer 2 better at a larger current, and the light-emitting chip epitaxial layer can have better light efficiency at different emission wavelengths.

[0060] Exemplarily, the Stark effect enhancement layer 11 may include sub-layers arranged alternately with high and low potential energies, such that when electrons pass through the Stark effect enhancement layer 11, they repeatedly move from a low electric potential to a high electric potential, thereby reducing the kinetic energy of the electrons. Additionally, the positive electrode has an excess of positive charges and lacks negatively charged electrons. When the positive charges neutralize the electrons, it also promotes the deceleration of the electrons. At the same time, since the electric field strength near the positive electrode is greater than that near the negative electrode, the electric force exerted on the electrons near the positive electrode is also greater, which further promotes the deceleration of the electrons; thereby increasing the concentration of electron-hole pairs in the active region. It can be seen that setting the Stark effect enhancement layer 11 in the N-type semiconductor layer can well achieve the effect of weakening the kinetic energy of electrons.

[0061] In order to more greatly reduce the kinetic energy of electrons, the number of layers of the Stark effect enhancement layer 11 can be set to be relatively large, for example, not less than 10 layers or not less than 15 layers. Exemplarily, it can be set to 12 layers, 14 layers, 16 layers, 18 layers, 20 layers, 22 layers, and so on. It can be understood that the effect of reducing the kinetic energy of electrons may be different for different structures of the Stark effect enhancement layer 11, and the number of its layers can be set according to the actual situation in practical applications.

[0062] As Figure 4 shown, in one implementation manner of this embodiment, each layer of the Stark effect enhancement layer 11 includes a first GaN sub-layer 111, a first AlGaN (aluminum gallium nitride) sub-layer 112, an AlN sub-layer 113 (aluminum nitride), a second AlGaN sub-layer 114, and a second GaN sub-layer 115 arranged in sequence. As Figure 5 (a) shows, between the sub-layers of the above-mentioned Stark effect enhancement layer 11, the potential energy height (shown as the longitudinal height in the figure) increases layer by layer and then decreases layer by layer. The multiple layers of the Stark effect enhancement layer 11 cause the potential energy height to change repeatedly, thereby reducing the kinetic energy of electrons. In order to effectively enhance the quantum-confined Stark effect, the above-mentioned Stark effect enhancement layer 11 is usually not less than 10 layers. In some implementation manners, the number of layers of the above-mentioned Stark effect enhancement layer 11 is not more than 15 layers or 20 layers. For example, it can be set to 12 layers, 14 layers, or can also be set to 16 layers, 18 layers, 20 layers, etc.

[0063] The change trends of the doping concentration and the Al component content in the Stark effect enhancement layer 11 of the foregoing example can be respectively as Figure 5 (b) and Figure 5 (c) shown, Figure 5 (b)'s longitudinal height reflects the relative level of its doping concentration, Figure 5 (c)'s longitudinal height reflects the relative level of its Al component concentration.

[0064] In a specific example, the doping concentration range of the first GaN sub-layer 111 is 1E 18 atoms per cubic centimeter to 8E 18atoms per cubic centimeter, such as 2E 18 atoms per cubic centimeter, 3E 18 atoms per cubic centimeter, 4E 18 atoms per cubic centimeter, 5E 18 atoms per cubic centimeter, 6E 18 atoms per cubic centimeter, 7E 18 atoms per cubic centimeter, etc.; the thickness range can be set to 0.5 nm to 2 nm, such as 0.8 nm, 1 nm, 1.2 nm, 1.5 nm, 1.7 nm, etc.

[0065] The doping concentration range of the first AlGaN sub-layer 112 is 1E 17 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter, such as 2E 17 atoms per cubic centimeter, 3E 17 atoms per cubic centimeter, 4E 17 atoms per cubic centimeter, 5E 17 atoms per cubic centimeter, etc.; the thickness range can be set to 0.3 nm to 1.8 nm, such as 0.5 nm, 0.8 nm, 1 nm, 1.2 nm, 1.5 nm, etc.;

[0066] The doping concentration range of the AlN sub-layer 113 is 0 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter, such as 1E 17 atoms per cubic centimeter, 2E 17 atoms per cubic centimeter, 3E 17 atoms per cubic centimeter, 4E 17 atoms per cubic centimeter, 5E 17 atoms per cubic centimeter, 6E 17 atoms per cubic centimeter, 7E 17 atoms per cubic centimeter, etc.; the thickness range can be set to 0.1 nm to 1 nm, such as 0.3 nm, 0.5 nm, 0.7 nm, 0.9 nm, etc.;

[0067] The doping concentration range of the second AlGaN sub-layer 114 is 1E 17 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter, such as 2E 17 atoms per cubic centimeter, 3E 17 atoms per cubic centimeter, 4E 17 atoms per cubic centimeter, 5E 17 etc. atoms per cubic centimeter, and its thickness range can be set to 0.3 nm to 1.8 nm, such as 0.5 nm, 0.8 nm, 1 nm, 1.2 nm, 1.5 nm, etc.;

[0068] The doping concentration of the second GaN sub-layer 115 ranges from 1E 18 atoms per cubic centimeter to 8E 18 atoms per cubic centimeter, such as 2E 18 atoms per cubic centimeter, 3E 18 atoms per cubic centimeter, 4E 18 atoms per cubic centimeter, 5E 18 atoms per cubic centimeter, 6E 18 atoms per cubic centimeter, 7E 18 atoms per cubic centimeter, etc. Its thickness range can be set to 0.5 nm to 2 nm, such as 0.8 nm, 1 nm, 1.2 nm, 1.5 nm, 1.7 nm, etc.;

[0069] Among them, the Al component content range in the first AlGaN sub-layer 112 and the second AlGaN sub-layer 114 can be configured to be 3% to 20%, such as 5%, 7%, 10%, 13%, 15%, 18%, etc.

[0070] Each Stark effect enhancement layer 11 can be completely the same. In some implementation processes, there can also be certain differences configured between different Stark effect enhancement layers 11. Within a single sub-layer, the doping concentration can remain unchanged or can have certain variations. For example, in some implementation manners, the doping concentration in a single AlN sub-layer 113 first decreases and then increases along its growth direction; as an example, when growing the AlN sub-layer 113, its doping concentration can gradually decrease from the initial concentration to 0 atoms per cubic centimeter, and then gradually increase from 0 atoms per cubic centimeter to the initial concentration. The initial concentration can be 1E 17 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter. This process of gradual change in doping concentration can be linear or non-linear. By making the average doping concentration in the AlN sub-layer 113 lower through the gradual change method, not only the growth quality is ensured, but also the effect of reducing the electron kinetic energy is further increased by using a lower doping, which is beneficial to better enhancing the quantum-confined Stark effect of the active layer 2.

[0071] In traditional applications, the number of periods of the quantum barrier layer 21 and the quantum well layer 22 in the active layer 2 is usually configured to be about 10. The design of the number of periods is only to meet the requirement of monochromatic light emission and ensure stable light emission within a fixed driving voltage range. In some embodiments of the present embodiment, the number of periods of the quantum barrier layer 21 and the quantum well layer 22 in the active layer 2 is configured to be not less than 15. As mentioned above, this will make the region where the wave functions of electron-hole pairs overlap larger in the active layer 2, weaken the rapid decline of the light efficiency when the current increases, and thus enhance the influence that can be generated by the quantum-confined Stark effect. The number of periods of the quantum barrier layer 21 and the quantum well layer 22 can be configured to be more, such as 17 periods, 19 periods, or even more than 20 periods, such as 21 periods, 23 periods, etc. In practical applications, the specific number of periods of the quantum barrier layer 21 and the quantum well layer 22 can be configured according to the overlap of the wave functions of electron-hole pairs. For example, the number of periods can be determined such that the wave functions of electron-hole pairs can form a good overlap in the last 4-5 quantum well layers 22 or even a larger range. In some embodiments, considering the overall thickness and performance, the number of periods of the quantum barrier layer 21 and the quantum well layer 22 can be set to be not higher than 20, that is, the number of periods of the quantum barrier layer 21 and the quantum well layer 22 ranges from 15 to 20, and usually a good overlap of the wave functions of electron-hole pairs can be obtained.

[0072] The present embodiment does not limit the material of the light-emitting chip epitaxial layer. According to the differences in its materials and components, the emission wavelength of the active layer 2 also varies accordingly. In the present embodiment, regardless of the maximum emission wavelength of the active layer 2, as the current increases, a blue shift of 60 nanometers can be generated on the basis of its maximum emission wavelength.

[0073] To simplify the light-emitting chip epitaxial layer and make it easier to fabricate, in some embodiments, the quantum barrier layer 21 includes GaN, the quantum well layer 22 includes InGaN (indium gallium nitride), and the active layer 2 is configured to have an emission wavelength corresponding to green, and as the current increases, the emission wavelength moves to the emission wavelength corresponding to blue. Through a wavelength shift of at least 60 nanometers, the transition from green light to blue light can be achieved. It can be seen that in some embodiments, the light-emitting chip epitaxial layer can achieve dual-color display of green and blue. At low currents, the emission wavelength of the active layer 2 is in the green band, and at high currents, the emission wavelength of the active layer 2 is in the blue band. The In component content of the green light-emitting chip is relatively high, and the stress between the GaN material quantum barrier layer 21 and the InGaN material quantum well layer 22 is relatively large, further enhancing the quantum-confined Stark effect, and the wavelength blue shift is relatively obvious; it can relatively easily achieve a large range of wavelength blue shift and achieve the effect of dual-color light emission.

[0074] For another example, the active layer 2 can also be configured to have a light-emitting wavelength corresponding to red, and as the current increases, the light-emitting wavelength moves to the light-emitting wavelength corresponding to green, realizing dual-color display of red and green. In this example, the active layer 2 with a light-emitting wavelength corresponding to red can also adopt InGaN and GaN materials. In other examples, the material of the active layer 2 can also be other materials.

[0075] In some embodiments, the N-type semiconductor layer further includes a stress relaxation layer 15 adjacent to the active layer 2. The stress relaxation layer 15 can slow down dislocations and stress before growing subsequent materials, ensuring better growth of the active layer 2.

[0076] In some embodiments, the P-type semiconductor layer further includes a hole accumulation layer 31 disposed on the active layer 2. The hole accumulation layer 31 can serve as a relay station for hole migration, ensuring the effective number and distribution of holes in the active region.

[0077] The epitaxial layer of the light-emitting chip in this embodiment can be fabricated into a light-emitting chip. In practical applications, a single epitaxial layer of the light-emitting chip can usually be fabricated into multiple light-emitting chips. Based on the epitaxial layer of the light-emitting chip in this embodiment, a MicroLED chip can be fabricated, but it is not limited thereto. For example, a Mini LED (Mini Light Emitting Diode, submillimeter light-emitting diode) chip can also be fabricated. It can be understood that for light-emitting chips of different sizes, the specific parameter performance of the epitaxial layer of the light-emitting chip can be adjusted, and this application does not limit this. Each light-emitting chip can be closely arranged in an array during fabrication, and the epitaxial layer of the light-emitting chip is divided into multiple regions and corresponds to the light-emitting chips one by one. To simplify the fabrication process of the display product, the interval for fabricating the epitaxial layer of the light-emitting chip into a light-emitting chip can be designed according to the requirements in the display product, and the fabricated light-emitting chips can be transferred and utilized as a whole. The light-emitting chip can be fabricated into a front-mounted or flip-chip structure, or a vertical structure.

[0078] This embodiment also provides a light-emitting chip, which includes the above-mentioned epitaxial layer of the light-emitting chip, a first electrode, and a second electrode. Among them, the first electrode is connected to the first semiconductor layer 1, and the second electrode is connected to the second semiconductor layer 3; the first electrode and the second electrode are N-type and P-type respectively. Exemplarily, when the first semiconductor layer 1 is an N-type semiconductor layer, the first electrode is an N-type electrode 41. The light-emitting chip in this embodiment can be a Micro LED chip, and in some examples, it can also be a Mini LED chip, etc. See Figure 6As shown, an example of a vertical - structured light - emitting chip is presented. It sequentially includes an N - type electrode 41, a first semiconductor layer 1 disposed on the N - type electrode 41, an active layer 2, a second semiconductor layer 3 disposed on the active layer 2, and a P - type electrode 42 connected to the second semiconductor layer 3. In some examples, the light - emitting chip includes an ohmic contact layer. The ohmic contact layer can be disposed between the N - type electrode 41 and the N - type semiconductor layer, or between the P - type electrode 42 and the P - type semiconductor layer, or ohmic contact layers are provided at both places. The material of the ohmic contact layer includes, but is not limited to, transparent conductive materials such as ITO (indium tin oxide). For the light - emitting chip of this embodiment, by designing the ohmic contact resistance of the ohmic contact layer, it can have a predetermined current under a predetermined driving voltage, so as to achieve a predetermined emission wavelength. For each light - emitting chip formed by the epitaxial layer of the light - emitting chip, different ohmic contact resistances can be formed, so that the light - emitting chips fabricated from the same epitaxial layer of the light - emitting chip can directly achieve two different emission wavelengths under the same driving voltage. In practical applications, the light - emitting chip can be fabricated separately and then transferred to the circuit board, or the epitaxial layer of the light - emitting chip of this application can be directly transferred to the circuit board, and the light - emitting chip can be directly fabricated on the circuit board. This application does not limit this.

[0079] See Figure 7 As shown, this embodiment also provides a method for fabricating an epitaxial layer of a light - emitting chip. The steps include, but are not limited to:

[0080] S101. Set a first semiconductor layer on the substrate;

[0081] S102. Set an active layer on the first semiconductor layer. The active layer is configured to have a quantum - confined Stark effect, and the quantum - confined Stark effect causes the emission wavelength of the active layer to have a wavelength shift of more than 60 nanometers at different currents;

[0082] S103. Set a second semiconductor layer on the active layer;

[0083] The epitaxial layer of the light - emitting chip fabricated by the above - mentioned method for fabricating an epitaxial layer of a light - emitting chip can be the epitaxial layer of the light - emitting chip described above in this embodiment. The first semiconductor layer 1 is an N - type semiconductor layer or a P - type semiconductor layer, and the second semiconductor layer 3 has a different conductivity type from the first semiconductor layer 1. In some examples, the N - type semiconductor layer can be grown first, that is, the first semiconductor layer 1 is an N - type semiconductor layer. In other examples, the P - type semiconductor layer can also be grown first, then the first semiconductor layer 1 is a P - type semiconductor layer.

[0084] The active layer 2 of the light-emitting chip epitaxial layer fabricated by the above method for fabricating a light-emitting chip epitaxial layer has a wavelength shift of more than 60 nm in the emission wavelength at different currents. For a light-emitting chip fabricated using this light-emitting chip epitaxial layer, the required emission color can be obtained by controlling the current magnitude under its driving voltage. Alternatively, different driving voltages can be directly supplied to different light-emitting chips during driving, so that the light-emitting chips formed from the same light-emitting chip epitaxial layer emit different emission colors. Therefore, the above light-emitting chip epitaxial layer simplifies the fabrication of dual-color integrated display products.

[0085] In some embodiments, when setting the N-type semiconductor layer, it includes: setting not less than 10 Stark effect enhancement layers 11, and the Stark effect enhancement layer 11 is configured to reduce the kinetic energy of electrons.

[0086] See Figure 8 , in some embodiments, the steps of setting each layer of the Stark effect enhancement layer 11 include:

[0087] S201. Grow a first GaN sub-layer in a growth pressure range of 300 mbar to 600 mbar;

[0088] S202. Grow a first AlGaN sub-layer in a growth pressure range of 100 mbar to 400 mbar;

[0089] S203. Grow an AlN sub-layer in a growth pressure range of 30 mbar to 100 mbar;

[0090] S204. Grow a second AlGaN sub-layer in a growth pressure range of 100 mbar to 400 mbar;

[0091] S205. Grow a second GaN sub-layer in a growth pressure range of 300 mbar to 600 mbar;

[0092] Among them, the growth temperature range of each sub-layer is 1020 °C to 1100 °C. See Figure 9 , this embodiment also provides a specific structure of a light-emitting chip epitaxial layer. The light-emitting chip epitaxial layer in this example realizes dual-color display of blue and green. The following is an explanation in combination with its fabrication process. The fabrication process of the light-emitting chip epitaxial layer in this example includes but is not limited to:

[0093] S301. See Figure 9 of (a), provide a substrate 5. The material of the light-emitting chip epitaxial layer in this example is mainly GaN, and the substrate 5 can be made of materials such as Al2O3, SiC, Si, or GaN.

[0094] S302. See Figure 9(b), an undoped GaN buffer layer 12 is grown on the substrate 5. The GaN buffer layer 12 is used to relieve stress and defects caused by lattice mismatch. Exemplarily, the thickness range of the GaN buffer layer 12 can be 1.8 μm to 2.3 μm, such as 1.9 μm, 2 μm, 2.1 μm, 2.2 μm, etc.

[0095] S303. Refer to Figure 9 (c), an N-doped GaN layer 13 is grown on the GaN buffer layer 12. In this example, silicon is used as the N-doping source for GaN, and its doping concentration range can be 1E 19 atoms per cubic centimeter to 2.5E 19 atoms per cubic centimeter, such as 1.3E 19 atoms per cubic centimeter, 1.5E 19 atoms per cubic centimeter, 1.7E 19 atoms per cubic centimeter, 1.9E 19 atoms per cubic centimeter, 2.1E 19 atoms per cubic centimeter, 2.3E 19 atoms per cubic centimeter, etc. The thickness range of the N-doped GaN layer 13 can be 1 μm to 1.5 μm, such as 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, etc.

[0096] S304. Refer to Figure 9 (d), a multi-layer Stark effect enhancement layer 11 is grown on the N-doped GaN layer 13. The number of layers of the Stark effect enhancement layer 11 is configured to be 10 to 20 layers. In this example, the total thickness range of the Stark effect enhancement layer 11 is controlled within 80 nanometers to 100 nanometers, such as 85 nanometers, 90 nanometers, 95 nanometers, etc. In this example, the Stark effect enhancement layer 11 is configured with a relatively large number of layers, which strongly weakens the kinetic energy of electrons, enhances the quantum-confined Stark effect of the active layer 2. At the same time, in this example, when setting the multi-layer Stark effect enhancement layer 11, its total thickness is controlled not to be too high to avoid significantly increasing the total thickness of the light-emitting chip epitaxial layer, which is convenient for the subsequent process production.

[0097] The following also exemplifies a specific structure of the Stark effect enhancement layer 11 and its manufacturing process, which includes but is not limited to:

[0098] S401. Grow a first GaN sub-layer 111, the growth temperature range of which can be 1020 °C to 1100 °C, such as 1050 °C, 1080 °C, etc.; the growth pressure range can be 300 mbar to 600 mbar, such as 400 mbar, 450 mbar, 500 mbar, 550 mbar, etc.; as in the previous examples of this embodiment, the thickness range can be 0.5 nanometers to 2 nanometers, and the doping concentration range is 1E 18~8E atoms per cubic centimeter 18 atoms per cubic centimeter. When growing the first GaN sub-layer 111 and other gallium-containing structures, trimethylgallium (TMGa) can be used as the gallium source, but it is not limited to this.

[0099] S402. Grow the first AlGaN sub-layer 112. Its growth temperature can be maintained at the same temperature as that of the aforementioned first GaN sub-layer 111, and the growth pressure is switched to the range of 100 mbar to 400 mbar, such as 150 mbar, 200 mbar, 250 mbar, 300 mbar, 350 mbar, etc.; as in the examples of this embodiment mentioned above, the thickness range can be 0.5 nm to 2 nm, and the doping concentration range can be 1E 17 ~8E atoms per cubic centimeter 17 atoms per cubic centimeter, and the Al component content range can be configured to be 3% to 20%. The growth source of the first AlGaN sub-layer 112 can include trimethylgallium (TMGa) and trimethylaluminum (TMAl), but it is not limited to this.

[0100] S403. Grow the AlN sub-layer 113. Its growth temperature can continue to be maintained unchanged, and the growth pressure is switched to the range of 30 mbar to 100 mbar, such as 40 mbar, 50 mbar, 60 mbar, 70 mbar, 80 mbar, 90 mbar, etc.; as in the examples of this embodiment mentioned above, the thickness can be 0.1 nm to 1 nm, and the initial doping concentration range is 1E 17 ~8E atoms per cubic centimeter 17 atoms per cubic centimeter. The growth source of the AlN sub-layer 113 can include trimethylaluminum (TMAl), but it is not limited to this. In this example, during the growth of the AlN sub-layer 113, the doping concentration gradually decreases from the initial concentration to 0 atoms per cubic centimeter, and then gradually increases from 0 atoms per cubic centimeter to the initial concentration. Exemplarily, during the growth of a single AlN sub-layer 113, first control the input amount of the doping source to gradually decrease from the initial value to 0, and then control the input amount of the doping source to gradually increase from 0 to the initial value; the doping concentration range corresponding to the initial value is 1E 17 ~8E atoms per cubic centimeter 17 atoms per cubic centimeter.

[0101] S404. Grow the second AlGaN sub-layer 114. Its growth temperature can continue to be maintained unchanged, and the growth pressure is switched back to the range of 100 mbar to 400 mbar, such as 150 mbar, 200 mbar, 250 mbar, 300 mbar, 350 mbar, etc.; as in the examples of this embodiment mentioned above, the thickness range can be 0.3 nm to 1.8 nm, and the doping concentration range is 1E 17 ~8E atoms per cubic centimeter17 The Al component content range may be configured to be 3% to 20% per atom per cubic centimeter. The growth source of the second AlGaN sublayer 114 may include trimethyl gallium (TMGa) and trimethyl aluminum (TMAl), but is not limited thereto.

[0102] S405, growing a second GaN sublayer 115, the growth temperature of which can continue to remain unchanged; the growth pressure is switched to a range of 300 mbar to 600 mbar, such as 400 mbar, 450 mbar, 500 mbar, 550 mbar, etc.; as in the above example of this embodiment, the thickness range can be 0.5 nanometers to 2 nanometers, and the doping concentration range is 1E 18 Atoms per cubic centimeter ~ 8E 18 Atoms per cubic centimeter. The growth source of the second GaN sublayer 115 may include trimethylgallium (TMGa), but is not limited thereto.

[0103] The above steps S401 to S405 illustrate the manufacture of one layer of Stark effect enhancement layer 11 . All Stark effect enhancement layers 11 are manufactured by repeating the above steps 10 to 20 times.

[0104] S305, see Figure 9 (e), a low-doped GaN layer 14 is grown on the Stark effect enhancement layer 11, and its doping concentration is relatively low, and the doping concentration range is 6E 17 Atoms per cubic centimeter ~ 2E 18 atoms per cubic centimeter, e.g. 7E 17 atoms per cubic centimeter, 8E 17 atoms per cubic centimeter, 9E 17 atoms per cubic centimeter, 1E 18 atoms per cubic centimeter, etc. The thickness of the low-doped GaN layer 14 can range from 40 nanometers to 60 nanometers, such as 45 nanometers, 50 nanometers, 55 nanometers, etc. Inserting the low-doped GaN layer 14 between the stress release layer 15 and the Stark effect enhancement layer 11 with a higher N-type doping concentration can cover the high-doped rough interface, which is beneficial to ensure the growth quality of the subsequent structure.

[0105] S306, see Figure 9 (f), growing a stress release layer 15 on the low-doped GaN layer 14; see Figure 10 In this example, the stress release layer 15 includes InxGa1 -xN层 151 and GaN layer 152; illustratively, the value range of x is 0.01 to 0.08, such as 0.03, 0.05, 0.07, etc., and the setting period range can be 3 to 9, such as 5, 6, 8, etc. -xN层The thickness range of 151 can be from 0.5 nanometers to 1.5 nanometers, such as 0.7 nanometers, 1 nanometer, 1.3 nanometers, etc.; in some examples, InxGa1 -xN层 The thickness range of 151 can also be from 0.5 nanometers to 3 nanometers, such as it can also be 1.7 nanometers, 2 nanometers, 2.5 nanometers, etc. The thickness range of GaN layer 152 can be from 1.5 nanometers to 4.5 nanometers, such as 2 nanometers, 3 nanometers, 4 nanometers, etc.; in some examples, the thickness range of GaN layer 152 can also be from 1.5 nanometers to 5 nanometers. In this example, the quantum well layer 22 of active layer 2 will also adopt In y Ga 1-y N material, where the value range of y can be from 0.06 to 0.18, such as 0.08, 0.1, 0.12, 0.14, 0.16, etc. The In component content in stress release layer 15 is lower than that in quantum well layer 22. By means of stress release layer 15, the growth stress is relieved. When active layer 2 is growing, a higher concentration of In component is more likely to be injected.

[0106] S307. Refer to Figure 9 (g). Grow active layer 2 on stress release layer 15. In this example, active layer 2 includes a plurality of periods of quantum barrier layers 21 (the material includes GaN) and quantum well layers 22 (the material includes In y Ga 1-y N) arranged alternately. Exemplarily, the value of y is 0.12, and the range of the number of set periods can be from 15 to 20. In this example, the thickness range of each quantum barrier layer 21 can be from 5 nanometers to 15 nanometers, such as 7 nanometers, 9 nanometers, 11 nanometers, 13 nanometers, etc.; the thickness range of each quantum well layer 22 can be from 1.5 nanometers to 3.5 nanometers, such as 2 nanometers, 2.5 nanometers, 3 nanometers, etc. Compared with about 10 periods in the traditional active layer 2, the number of periods of quantum barrier layer 21 and quantum well layer 22 in this example is increased, and the overlapping region of the wave functions of electron-hole pairs is larger. In some implementation processes, cooperating with the Stark effect enhancement layer 11 to weaken the kinetic energy of electrons, it can make the wave functions of electron-hole pairs overlap well in the last 4 to 5 quantum well layers 22, further enhancing the quantum-confined Stark effect. The active layer 2 of this example can have a corresponding green emission wavelength, and the strong quantum-confined Stark effect enables it to have a wavelength shift of more than 60 nanometers under different currents; as the current increases, affected by the quantum-confined Stark effect, its emission wavelength can be blue-shifted to the blue range, realizing dual-color emission.

[0107] S308. Refer to Figure 9(h), a hole-accumulating layer 31 is grown on the active layer 2. In this example, the hole-accumulating layer 31 includes a GaN material, and the set thickness range can be 60 nanometers to 80 nanometers, such as 65 nanometers, 70 nanometers, 75 nanometers, etc.; the hole-accumulating layer 31 is doped with a P-type doping source. In this example, Mg is used as the P-type doping source, and its doping concentration is greater than 1E 19 atoms per cubic centimeter, for example, it can be 2E 19 atoms per cubic centimeter, 3E 19 atoms per cubic centimeter, 4E 19 atoms per cubic centimeter, etc.

[0108] S309, see Figure 9 (i), a P-type doped GaN layer 32 is grown on the hole-accumulating layer 31. In this example, Mg is used as the P-type doping source of GaN, and its doping concentration range can be 3E 19 atoms per cubic centimeter to 1E 20 atoms per cubic centimeter, for example, it can be 4E 19 atoms per cubic centimeter, 6E 19 atoms per cubic centimeter, 8E 19 atoms per cubic centimeter, etc. The thickness of the P-type doped GaN layer 32 can be 100 nanometers to 140 nanometers, such as 110 nanometers, 120 nanometers, 130 nanometers, etc.

[0109] In this example, the total thickness range of the light-emitting chip epitaxial layer can be controlled at about 3.8 μm, exemplarily 3.6 μm to 4 μm, such as 3.7 μm, 3.8 μm, 3.9 μm, etc., and Micro LED chips with a pixel size of about 2 μm or even smaller can be fabricated. The relatively thin thickness also facilitates the subsequent manufacturing process and leaves more space for setting other structures such as microlenses.

[0110] For the epitaxial layer of the light-emitting chip in the above example, by providing a relatively large number of Stark effect enhancement layers 11 to reduce the kinetic energy of electrons and increasing the setting period of the active layer 2, the overlapping region of the wave functions of electron-hole pairs is made larger, thus having a strong quantum-confined Stark effect and a luminescence wavelength shift of more than 60 nm at different currents. This enables the light-emitting chip to exhibit different luminescence colors merely by being configured with different drive currents, without the need for complex design in the subsequent process, making the fabrication of dual-color integrated display products simpler. In some implementation processes, for a single light-emitting chip fabricated from the above epitaxial layer of the light-emitting chip, a current of about 0 μA to 10 μA can achieve a wavelength shift from green light to blue light at a size of 15 μm * 30 μm. Of course, in actual applications, due to differences in processes and sizes, the current range for achieving a wavelength shift from green light to blue light also varies, and this is not limited. Moreover, structures such as the stress relaxation layer 15 and the hole accumulation layer 31 also ensure the quality during the fabrication of the epitaxial layer of the light-emitting chip and have a positive effect on achieving a strong quantum-confined Stark effect.

[0111] It should be understood that the application of this application is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of this application.

Claims

1. A light-emitting chip epitaxial layer, characterized in that, Comprising: A first semiconductor layer; An active layer disposed on the first semiconductor layer; And A second semiconductor layer disposed on a side of the active layer away from the first semiconductor layer; Wherein, the first semiconductor layer is an N-type semiconductor layer or a P-type semiconductor layer, and the second semiconductor layer has a different conductivity type from the first semiconductor layer; the active layer is configured to have a quantum-confined Stark effect, and the quantum-confined Stark effect causes the emission wavelength of the active layer at different currents to have a wavelength shift of more than 60 nanometers.

2. The epitaxial layer of the light-emitting chip according to claim 1, wherein The N-type semiconductor layer includes no less than 10 layers of Stark effect enhancement layers, and the Stark effect enhancement layers are configured to reduce the kinetic energy of electrons.

3. The epitaxial layer of the light-emitting chip according to claim 2, wherein Each layer of the Stark effect enhancement layer includes a first GaN sub-layer, a first AlGaN sub-layer, an AlN sub-layer, a second AlGaN sub-layer, and a second GaN sub-layer arranged in sequence.

4. The epitaxial layer of the light-emitting chip according to claim 3, wherein The number of layers of the Stark effect enhancement layer is not higher than 20 layers.

5. The epitaxial layer of the light-emitting chip according to claim 3, wherein, The doping concentration range of the first GaN sublayer is 1E 18 atoms per cubic centimeter to 8E 18 atoms per cubic centimeter, and the thickness range is 0.5 nanometers to 2 nanometers; The doping concentration range of the first AlGaN sublayer is 1E 17 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter, and the thickness range is 0.3 nanometers to 1.8 nanometers; The doping concentration range of the AlN sub-layer is from 0 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter, and the thickness range is from 0.1 nanometer to 1 nanometer; The doping concentration range of the second AlGaN sublayer is 1E 17 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter, and the thickness range is 0.3 nanometers to 1.8 nanometers; The doping concentration range of the second GaN sublayer is 1E 17 atoms per cubic centimeter to 8E 18 atoms per cubic centimeter, and the thickness range is 0.5 nanometers to 2 nanometers; The Al component content in the first AlGaN sub-layer and the second AlGaN sub-layer ranges from 3% to 20%.

6. The epitaxial layer of the light-emitting chip according to claim 3, wherein The doping concentration in a single AlN sub-layer first decreases and then increases along its growth direction.

7. The epitaxial layer of the light-emitting chip according to any one of claims 1-6, characterized in that, The active layer includes alternately arranged quantum barrier layers and quantum well layers, and the setting period of the quantum barrier layers and the quantum well layers is not less than 15.

8. The epitaxial layer of the light-emitting chip according to claim 7, characterized in that The setting period of the quantum barrier layers and the quantum well layers is not higher than 20.

9. The epitaxial layer of the light-emitting chip according to claim 7, wherein The quantum barrier layer includes GaN, the quantum well layer includes InGaN, the active layer is configured to have an emission wavelength corresponding to green, and as the current increases, the emission wavelength moves to an emission wavelength corresponding to blue.

10. The epitaxial layer of the light-emitting chip according to any one of claims 1-6, characterized in that The N-type semiconductor layer further includes a stress release layer adjacent to the active layer, and / or, the P-type semiconductor layer further includes a hole accumulation layer disposed on the active layer.

11. A method for fabricating an epitaxial layer of a light-emitting chip, characterized in that, Comprising: Setting a first semiconductor layer on a substrate; Setting an active layer on the first semiconductor layer; And Setting a second semiconductor layer on the active layer; Wherein, the first semiconductor layer is an N-type semiconductor layer or a P-type semiconductor layer, and the second semiconductor layer has a different conductivity type from the first semiconductor layer; the active layer is configured to have a quantum-confined Stark effect, and the quantum-confined Stark effect causes the emission wavelength of the active layer at different currents to have a wavelength shift of more than 60 nanometers.

12. The manufacturing method of the light-emitting chip epitaxial layer according to claim 11, characterized in that, When setting the N-type semiconductor layer, it includes: Setting no less than 10 layers of Stark effect enhancement layers, and the Stark effect enhancement layers are configured to reduce the kinetic energy of electrons.

13. The manufacturing method of the light-emitting chip epitaxial layer according to claim 12, characterized in that, The steps of setting each layer of the Stark effect enhancement layer include: Growing a first GaN sub-layer in a growth pressure range of 300 mbar to 600 mbar; growing a first AlGaN sub-layer in a growth pressure range of 100 mbar to 400 mbar; Growing an AlN sub-layer in a growth pressure range of 30 mbar to 100 mbar; Growing a second AlGaN sub-layer in a growth pressure range of 100 mbar to 400 mbar; Growing a second GaN sub-layer in a growth pressure range of 300 mbar to 600 mbar; The growth temperature range of each sub-layer is 1020°C to 1100°C.

14. The method for fabricating the epitaxial layer of the light-emitting chip according to claim 13, characterized in that, During the process of growing a single AlN sublayer, first control the input amount of the doping source to gradually decrease from the initial value to 0, and then control the input amount of the doping source to gradually increase from 0 to the initial value; the doping concentration range corresponding to the initial value is 1E 17 atoms per cubic centimeter to 8E 17 atoms per cubic centimeter.

15. A light-emitting chip, characterized in that, Including: The light-emitting chip epitaxial layer according to any one of claims 1-10; A first electrode connected to the first semiconductor layer; And A second electrode connected to the second semiconductor layer.

Images