A semiconductor light emitting element and a light emitting device

Abstract

The present application provides a semiconductor light emitting element and a light emitting device, the epitaxial structure of the light emitting element at least includes first semiconductor layer structure, active layer and second semiconductor layer structure stacked from bottom to top, the semiconductor light emitting element of the present application, the active layer includes Al y Ga 1‑y N barrier layer and Al x Ga 1‑x N well layer, wherein 0 a Ga 1‑a N material layer, wherein 0 a Ga 1‑a N material layer, thereby reducing the light absorption phenomenon of the P-type layer. In addition, the P-type layer can contain an Ohmic contact layer formed by a nitride material layer without Al, while controlling the thickness of the Ohmic contact layer to be below 10 nm to reduce the p-type gallium nitride material, thereby also reducing the absorption of light and improving the light emitting efficiency.

Description

Technical Field

[0001] This invention relates to the field of semiconductor devices and apparatus, and particularly to a semiconductor light-emitting element and light-emitting device. Background Technology

[0002] GaN-based LEDs, due to their high luminous efficiency, are currently widely used in various light source fields such as backlighting, general lighting, automotive lighting, and decoration. From a technical perspective, further improving the luminous efficiency of LED chips remains a key focus for the industry. Luminous efficiency is mainly determined by two factors: the first is the radiative recombination efficiency of electrons and holes in the active region, i.e., the internal quantum efficiency; the second is the light extraction efficiency.

[0003] For nitride light-emitting diodes (LEDs), various epitaxial structures are typically used to enhance their internal quantum efficiency in order to improve their luminous efficiency. One factor affecting the internal quantum efficiency is the light absorption characteristics of gallium nitride (GaN) material itself. To obtain better ohmic contacts and good material quality, traditional GaN epitaxial structures use thicker p-type GaN materials to grow p-type layers. However, thicker p-type GaN materials significantly absorb light below 370 nm, severely affecting the light extraction efficiency of the light-emitting element. Summary of the Invention

[0004] In view of the above-mentioned defects of nitride light-emitting diodes in the prior art, the present invention provides a semiconductor light-emitting element and light-emitting device, which solves one or more of the above-mentioned problems by improving the material selection and thickness setting of the P-type layer.

[0005] A first aspect of this application provides a semiconductor light-emitting element, comprising at least an epitaxial structure, wherein the epitaxial structure comprises at least a first semiconductor layer structure, an active layer, and a second semiconductor layer structure stacked from bottom to top, wherein the active layer comprises Al y Ga 1-y N-barrier layer and Al x Ga 1-x An N-well layer, wherein 0 < x < 1, 0 < y < 1, and the second semiconductor layer structure includes Al. a Ga 1-a N material layer, where 0 < a < 1.

[0006] According to another embodiment of the present invention, a light-emitting device is provided, which includes the semiconductor light-emitting element described in the present invention.

[0007] As described above, the semiconductor light-emitting element and light-emitting device of this application have the following beneficial effects:

[0008] In the semiconductor light-emitting element of this application, the active layer includes Al. y Ga 1-y N-barrier layer and Alx Ga 1-x An N-well layer, wherein 0 < x < 1, 0 < y < 1, and the second semiconductor layer structure includes Al. a Ga 1-a N-type material layer, where 0 < a < 1. As mentioned above, the P-type layer in this application is selected as Al. a Ga 1-a The N-type material layer reduces light absorption in the P-type layer. Additionally, the P-type layer can include an ohmic contact layer formed from an Al-free nitride material layer, with the thickness of the ohmic contact layer controlled below 10 nm to reduce the amount of p-type gallium nitride material, thereby also reducing light absorption and improving light extraction efficiency. Attached Figure Description

[0009] Figure 1 The diagram shown is a structural schematic of the light-emitting element provided in Embodiment 1 of the present invention.

[0010] Figure 2 Displayed as Figure 1 A schematic diagram of the structure of part A in the middle circle.

[0011] Figure 3 Shown as an optional embodiment Figure 1 A schematic diagram of the structure of part A in the middle circle.

[0012] Figure 4 Displayed as Figure 1 A schematic diagram of the concentration distribution of different elements in each layer of the epitaxial structure.

[0013] Figure 5 The diagram shows the concentration distribution of different elements in each layer of the epitaxial structure in one optional embodiment.

[0014] Figure 6 The diagram shown is a schematic diagram of the light-emitting device provided in Embodiment 2 of this application.

[0015] Component designation explanation

[0016] 100, Light-emitting element; 110, Substrate; 120, Epitaxial structure; 121, First semiconductor layer structure; 122, Active layer; 1221, Barrier layer; 1222, Potential well layer; 123, Second semiconductor layer structure; 1231, First layer structure; 1232, Second layer structure; 130, Protective layer; 140, First electrode; 150, Second electrode; 200, Light-emitting device; 201, Circuit board; 202, Light-emitting element. Detailed Implementation

[0017] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0018] The composition of each layer contained in this application can be analyzed by any suitable method, such as secondary ion mass spectrometry (SIMS); the thickness of each layer can be analyzed by any suitable method, such as transmission electron microscopy (TEM) or scanning electron microscopy (SEM), in conjunction with, for example, the depth position of each layer on a SIMS spectrum.

[0019] According to one embodiment of this application, a semiconductor light-emitting element is provided, which includes at least an epitaxial structure. The epitaxial structure includes at least a first semiconductor layer structure, an active layer, and a second semiconductor layer structure stacked from bottom to top, wherein the active layer includes Al. y Ga 1-y N-barrier layer and Al x Ga 1-x An N-well layer, wherein 0 < x < 1, 0 < y < 1, and the second semiconductor layer structure includes Al. a Ga 1-a N material layer, where 0 < a < 1.

[0020] As described above, the second semiconductor layer in the epitaxial structure is a P-type layer, and Al is selected. a Ga 1-a The N-material layer reduces the light absorption of the P-type layer and improves the light emission effect of the light-emitting element.

[0021] Optionally, the second semiconductor layer structure is a P-type doped layer, wherein the concentration of P-type dopant is greater than 1 × 10⁻⁶. 17 atom / cm 3 .

[0022] Optionally, the thickness of the second semiconductor layer structure is less than or equal to 200 nm.

[0023] Optionally, the Al a Ga 1-a The thickness of the N material layer is less than or equal to 200 nm.

[0024] By controlling the doping concentration of P-type dopant in the second semiconductor layer structure, and Al a Ga 1-aThe thickness of the N-material layer and the structure of the second semiconductor layer can provide enough holes for recombination while ensuring that the P-type dopants do not diffuse into the active layer. Therefore, it can reduce damage to the active layer and ensure the recombination efficiency of electrons and holes.

[0025] Optionally, the Al a Ga 1-a The thickness of the N-material layer accounts for 60%-100% of the thickness of the second semiconductor layer structure.

[0026] By controlling the Al in the second semiconductor layer structure a Ga 1-a The thickness ratio of the N-type material layer is minimized to reduce the amount of p-type gallium nitride material, thereby reducing the absorption of light by the p-type gallium nitride material and improving the light extraction efficiency of the light-emitting element.

[0027] Optionally, the second semiconductor layer structure may include an Al-free nitride material layer, wherein the thickness of the Al-free nitride material layer is less than or equal to 10 nm.

[0028] Optionally, the thickness of the Al-free nitride material layer is less than or equal to 5 nm. Optionally, the concentration of p-type dopant in the Al-free nitride material layer is greater than 5 × 10⁻⁶. 17 atom / cm 3 .

[0029] Optionally, the Al-free nitride material layer is located on the Al a Ga 1-a Above the N material layer.

[0030] The second semiconductor layer structure may include an Al-free nitride material layer formed on Al. a Ga 1-a Above the N-type material layer, such as a GaN or InGaN material layer, the thickness of the Al-free nitride material layer in the second semiconductor layer structure is controlled. The ohmic contact layer formed by the Al-free nitride material layer can, on the one hand, still ensure good ohmic contact capability; on the other hand, it can minimize the amount of p-type gallium nitride material, thereby reducing light absorption and improving light extraction efficiency.

[0031] Optionally, the Al a Ga 1-a The thickness of the N material layer is greater than the thickness of the Al-free nitride material layer.

[0032] Optionally, the Al a Ga 1-a The thickness of the N material layer is at least twice the thickness of the Al-free nitride material layer.

[0033] As described above, this application strictly controls the occupancy of the gallium nitride material layer without Al in the second semiconductor layer structure by controlling the position and thickness of the layer, thereby ensuring that it does not produce obvious light absorption and ensuring the light emission effect of the light-emitting element.

[0034] Optionally, the quantum well of the active layer is an In-free material layer.

[0035] Optionally, the emission wavelength of the active layer is between 220 nm and 410 nm.

[0036] Optionally, the emission wavelength of the active layer is between 240 nm and 370 nm.

[0037] Because p-type gallium nitride (GaN) materials exhibit significant light absorption in the ultraviolet wavelength range of light-emitting diodes (LEDs), especially below 370 nm, this severely impacts the light extraction efficiency of the LED. Therefore, in ultraviolet LEDs radiating this wavelength range, increasing the Al content in the second semiconductor layer structure... a Ga 1-a The proportion of N material layers can effectively reduce light absorption and improve light extraction efficiency.

[0038] According to another embodiment of the present invention, a light-emitting device is provided, which includes the semiconductor light-emitting element described in this invention. This light-emitting device includes the light-emitting element of this application, and therefore has good light emission performance and reliability.

[0039] Example 1

[0040] This embodiment provides a semiconductor light-emitting element (also known as an LED, light-emitting diode), such as Figure 1 As shown, the light-emitting element 100 includes at least one epitaxial structure 120, which includes at least a first semiconductor layer structure 121, an active layer 122, and a second semiconductor layer structure 123 stacked sequentially from bottom to top. The epitaxial structure 120 can be any epitaxial structure capable of radiating light under voltage, such as an AlGaInN-based epitaxial structure, an AlGaN-based epitaxial structure, or an AlGaInP-based epitaxial structure. In this embodiment, an AlGaN-based epitaxial structure capable of providing ultraviolet light is used as an example for explanation. Optionally, the light-emitting element 100 can be a right-mounted, flip-chip, or vertically mounted light-emitting element; this embodiment uses a flip-chip structure as an example for explanation.

[0041] The first semiconductor layer structure 121 described above can be an N-type layer, and correspondingly, the second semiconductor layer structure 123 can be a P-type layer, or vice versa. This embodiment takes the example where the first semiconductor layer structure 121 can be an N-type layer and the corresponding second semiconductor layer structure 123 can be a P-type layer.

[0042] In this embodiment, the aforementioned N-type semiconductor layer is an N-type AlGaN layer. This N-type AlGaN layer provides electrons and also serves as an ohmic contact layer during the subsequent formation of the first electrode 140. The N-type AlGaN layer provides electrons by doping with n-type impurities, such as Si, Ge, Sn, Se, and Te. In this embodiment, Si is preferred as the n-type impurity. The thickness of the N-type AlGaN layer is approximately 1 μm to 4 μm, and the Si doping concentration is 5 × 10⁻⁶. 18 atoms / cm 3 ~2×10 20 atoms / cm 3 Between these layers, electrons are provided for radiative recombination. The N-type AlGaN layer is the layer with the highest N-type doping concentration in the epitaxial structure 120. The N-type AlGaN layer can be a monolayer structure or a superlattice structure. The formation of the N-type AlGaN layer as a highly doped layer can reduce the contact resistance.

[0043] like Figure 1 As shown, an active layer 122 is formed above the first semiconductor layer structure 121. The active layer 122 is a region that provides light radiation by electron-hole recombination. Different materials can be selected according to different emission wavelengths. The active layer 122 can be a periodic structure of a single quantum well or multiple quantum wells composed of a quantum well layer 1222 and a barrier layer 1221. By adjusting the composition ratio of the semiconductor material in the active layer 122, it is desired to radiate light of different wavelengths. In some embodiments, the active layer 122 is an In-free material layer, for example, it can be an AlGaN / AlGaN multiple quantum well with 5 to 15 periods. Further, the active layer 122 can be doped with Si, and the Si doping concentration is between 1 × 10⁻⁶. 17 Atoms / cm 3 ~1×10 19 Atoms / cm 3 .

[0044] In this embodiment, as Figure 2 As shown, preferably, the active layer 122 includes p Al atoms. y Ga 1-y N barrier layers 1221 and q Al x Ga 1-x N-potential well layer 1222, Al y Ga 1-y N-barrier layer 1221 and Al x Ga 1-xThe N-level potential well layers 1222 are arranged alternately, where 0 < x < 1, 0 < y < 1, 1 ≤ p ≤ 20, and 1 ≤ q ≤ 20. The values ​​of p and q can be the same or different. The barrier layer 1221 has a larger band gap than the potential well layer 1222. The alternating arrangement of the barrier layer 1221 and the potential well layer 1222 in the active layer 122 enables the recombination of electrons and holes in the active layer 122. Al y Ga 1-y N-barrier layer 1221 and Al x Ga 1-x The alternating arrangement of the N-well layers 1222 ensures that the light emitted after electron-hole recombination is ultraviolet light with a wavelength of approximately 220 nm to 410 nm. Furthermore, both the barrier layer 1221 and the well layer 1222 in the active layer 122 of this application are AlGaN material layers, with similar lattice constants, resulting in good crystal growth quality and fewer dislocations or micro-pit defects in the active layer 122. This also helps prevent the diffusion of Mg atoms into the active layer 122. In an optional embodiment, the Al content in the active layer 122 is controlled to be above 30%, and further, above 50%. This control of the Al content and the selection of the constituent materials of the active layer 122 ensures effective recombination of electrons and holes in the active layer 122, ensuring the luminous effect of the ultraviolet light-emitting diode, so that the active layer 122 radiates ultraviolet light with a wavelength of approximately 300 nm. Optionally, the wavelength of the light radiated by the active layer 122 is between 220 nm and 410 nm, and more specifically, between 240 nm and 370 nm.

[0045] Refer again Figure 1 In this embodiment, the second semiconductor layer structure 123 is a P-type layer, which provides holes by doping with P-type impurities. The P-type impurities can be Mg, Zn, Ca, Sr, and Ba. Preferably, the P-type impurity is Mg. In an optional embodiment, the second semiconductor layer structure 123 includes an Al-containing gallium nitride material layer. The thickness H of the second semiconductor layer structure 123 is less than or equal to 200 nm, and further, H ≤ 100 nm. The thickness of the Al-containing gallium nitride material layer accounts for 60% to 100% of the thickness of the second semiconductor layer structure 123, and further, 70% to 100%, 80% to 100%, 90% to 100%, and 95% to 100%. The thickness setting of the second semiconductor layer structure 123 and the proportion of the Al-free gallium nitride material layer minimize the amount of p-type gallium nitride material, effectively reducing the light absorption phenomenon of the p-type gallium nitride material, thereby improving the light extraction efficiency of the light-emitting element. The doping concentration of Mg in the second semiconductor layer structure 123 is greater than or equal to 1 × 10⁻⁶. 17 atom / cm 3 Furthermore, the doping concentration of Mg is greater than or equal to 1 × 10⁻⁶. 17 atom / cm 3And less than or equal to 1×10 21 atom / cm 3 .

[0046] In one optional embodiment of this example, the second semiconductor layer structure 123 is a single material layer structure, i.e., as shown in the example below. Figure 2 As shown, the second semiconductor layer structure 123 includes a first layer structure 1231, which is Al a Ga 1-a N material layer, 0 < a < 1. In this embodiment, the thickness H1 of the first layer structure 1231 is less than or equal to 200 nm. Since the second semiconductor layer structure 123 only includes the above-mentioned Al... a Ga 1-a The first layer structure 1231 formed by the N material layer, namely Al a Ga 1-a The thickness H1 of the N material layer 1231 accounts for 100% of the thickness H of the second semiconductor layer 123, so there is basically no light absorption, which is beneficial to improving the light extraction efficiency of the light-emitting element. In addition, the above-mentioned first layer structure 1231 is formed above the active layer 122 and is disposed adjacent to the active layer 122. Since the first layer structure 1231 is an Al-containing material layer, it can block electrons from entering the second semiconductor layer structure 123 to a certain extent. Therefore, in this embodiment, the epitaxial structure 120 of the light-emitting element does not need to be provided with a separate electron blocking layer, which reduces the thickness of the epitaxial structure to a certain extent and reduces light absorption.

[0047] In another optional embodiment of this application, the second semiconductor layer structure 123 is a multilayer structure formed of different materials, optionally, such as Figure 3 As shown, the system may further include a second layer structure 1232, which is an Al-free nitride material layer. This Al-free nitride material layer can be a GaN material layer or an InGaN material layer, and the embodiments of the present invention are not limited thereto. The second layer structure 1232 is located above the first layer structure 1231, that is, the second layer structure 1232 is located on the side of the first layer structure 1231 away from the active layer 122. In this second layer structure 1232, the doping concentration of the P-type dopant is greater than 5 × 10⁻⁶. 17 atom / cm 3 .

[0048] In this optional embodiment, to minimize the light absorption of the Al-free second layer structure 1232, the thickness H2 of the second layer structure 1232 is controlled to be less than the thickness H1 of the first layer structure 1231, and H1 ≥ 2H2, further, H1 ≥ 3H2, H1 ≥ 4H2, or H1 ≥ 9H2. Even further, the thickness H2 of the second layer structure 1232 is controlled to be less than or equal to 10 nm, and even further, H2 is less than or equal to 5 nm. The second layer structure 132 is an Al-free material layer, which enables the subsequently formed metal electrode to form a good ohmic contact with the second semiconductor layer structure 123, ensuring the electrical performance of the light-emitting element; at the same time, by controlling the thickness of the second layer structure 1232, its light absorption is greatly reduced, and the light extraction efficiency of the light-emitting element is improved.

[0049] In the second semiconductor layer structure 123 having the structural features described above in this embodiment, the P-type dopant can have various different diffusion patterns. For example... Figure 4 As shown, in an optional embodiment, the position with a depth of 0 μm on the horizontal axis is used as the reference point, that is, the upper surface of the second semiconductor layer structure 123 of the epitaxial structure 120 is used as the reference point. The thickness of the second semiconductor layer structure 123 is in the range of 0 nm to 60 nm from this reference point, more specifically, in the range of 0 nm to 55 nm. The thickness of the active layer 122 is in the range of 50 nm to 130 nm from this reference point, more specifically, in the range of 55 nm to 125 nm. Within the above-mentioned depth range of the second semiconductor layer structure 123, along the diffusion direction of the P-type dopant, the concentration of the P-type dopant shows a trend of first decreasing and then increasing. The concentration of p-type dopant initially forms a first abruptly decreasing region L1, followed by a gradually increasing region L2, and then a steeply increasing region L3. The thickness of the first abruptly decreasing region L1 ranges from 0 to 20 nm, the thickness of the gradually decreasing region L2 ranges from 15 nm to 45 nm, and the thickness of the steeply increasing region L3 ranges from 40 nm to 55 nm. Within the first abruptly decreasing region L1, the concentration of p-type dopant is approximately 1 × 10⁻⁶. 17 atom / cm 3 ~1×10 21 atom / cm 3 That is, the concentration of P-type dopant starts from 1×10⁻⁶ 21 atom / cm 3 Plummeted to 1×10 17 atom / cm 3 After the initial drop region L1, the P-type dopant exhibits a slow upward trend, forming a gradual drop region L2. In the gradual drop region L2, the concentration of P-type dopant is between 1 × 10⁻⁶. 17 atom / cm 3 ~1×10 18 atom / cm 3That is, the concentration of P-type dopant starts from 1×10⁻⁶ 17 atom / cm 3 Slowly rise to 1×10 18 atom / cm 3 A concentration trough of the P-type dopant is formed between the first abruptly decreasing region L1 and the gradually increasing region L2, with the trough located at a depth of 15 nm to 25 nm in the second semiconductor layer structure. Subsequently, the concentration rapidly increases, forming a steeply increasing region L3, where the concentration of the P-type dopant is between 5 × 10⁻⁶. 17 atom / cm 3 ~1×10 19 atom / cm 3 That is, the concentration of P-type dopant starts from 5 × 10⁻⁶ 17 atom / cm 3 Rapidly rise to 1×10 19 atom / cm 3 After the steep rise region L3 mentioned above, Mg atoms enter the depth range of the active layer 122. At this time, as... Figure 4 As shown, the concentration of Mg atoms decreases sharply, forming a second steep drop region L4. The slope of the Mg atom concentration decrease in this second steep drop region L4 is greater than the slope of the Mg atom concentration decrease in the first steep drop region L1 in the second semiconductor layer structure 123. In this second steep drop region L4, the concentration of P-type dopant (Mg atoms) is between 1 × 10⁻⁶. 16 atom / cm 3 ~1×10 19 atom / cm 3 That is, the concentration of P-type dopant starts from 1×10⁻⁶. 19 atom / cm 3 Rapidly dropped to 1×10 16 atom / cm 3 That is, the active layer 122 after the second semiconductor layer structure 123 contains almost no diffused P-type dopants, such as Mg atoms.

[0050] Controlling the concentration of P-type dopant in the second semiconductor layer structure 123 ensures sufficient P-type dopant and adequate hole supply. Simultaneously, it ensures that Mg atoms are virtually absent within the aforementioned depth range of the active layer 122, reducing damage to the active layer and guaranteeing electron-hole recombination efficiency.

[0051] In another optional embodiment of this example, such as Figure 5As shown, the reference point is the location with a depth of 0 μm on the horizontal axis, which is the upper surface of the second semiconductor layer structure 123 of the epitaxial structure 120. The thickness of the second semiconductor layer structure 123 is in the range of 0 nm to 80 nm from this reference point, more specifically, in the range of 0 nm to 70 nm. The thickness of the active layer 122 is in the range of 60 nm to 130 nm from this reference point, more specifically, in the range of 65 nm to 120 nm. Within the aforementioned depth range of the second semiconductor layer structure 123, along the diffusion direction of the P-type dopant, the concentration of the P-type dopant forms a third abrupt drop region L5, and a gradual drop region L6 is formed at the rear end of the third abrupt drop region L5. In the third abrupt drop region L5, the concentration of the P-type dopant is between 1 × 10⁻⁶. 19 atom / cm 3 ~1×10 21 atom / cm 3 That is, in the third drop region L5, the concentration of P-type dopant decreases from 1×10⁻⁶. 21 atom / cm 3 Rapidly dropped to 1×10 19 atom / cm 3 In the descent region L6, the concentration of P-type dopant is between 1 × 10⁻⁶. 18 atom / cm 3 ~1×10 19 atom / cm 3 That is, in the slow-decline region L6, the concentration of P-type dopant decreases from 1×10⁻⁶. 19 atom / cm 3 Slowly decreasing to 1×10 18 atom / cm 3 Similarly, refer to Figure 5 The third abrupt descent region L5 is formed in the thickness range of 0 to 10 nm of the second semiconductor layer structure 123, and the gradual descent region L6 is formed in the thickness range of 10 to 50 nm of the second semiconductor layer structure 123.

[0052] In this optional embodiment, after the aforementioned gradual decrease region L6, the concentration of the P-type dopant forms a fourth rapid decrease region L7 and a buffer zone L8 located after the fourth rapid decrease region L7. (Refer to...) Figure 5 It can be seen that the concentration decrease slope of P-type dopant in the fourth steep drop region L7 is greater than that in the third steep drop region L5. Specifically, in the fourth steep drop region L7, the concentration of P-type dopant is between 1 × 10⁻⁶. 16 atom / cm 3 ~5×10 18 atom / cm 3 That is, in the fourth drop region L7, the concentration of P-type dopant decreases from 5 × 10⁻⁶. 18 atom / cm 3 Plummeted to 1×1016 atom / cm 3 In buffer L8, the concentration of P-type dopant is between 1 × 10⁻⁶. 16 atom / cm 3 ~5×10 17 atom / cm 3 That is, in buffer L8, the concentration of P-type dopant is from 5 × 10⁻⁶. 17 atom / cm 3 Slowly decreasing to 1×10 16 atom / cm 3 .

[0053] As described above, by controlling the diffusion characteristics of Mg atoms in the second semiconductor layer structure 123, it is ensured that the active layer 122 after the second semiconductor layer structure 123 contains almost no diffused P-type dopants, effectively reducing the influence of Mg atoms on the MQW and improving the quality of the MQW. Therefore, the recombination efficiency of electrons and holes in the active layer 123 is guaranteed, which is beneficial to improving the luminescence efficiency.

[0054] Similarly, Figure 1 As shown, the light-emitting element 100 also includes a protective layer 130 formed on the surface of the epitaxial structure 120. This protective layer 130 covers the upper surface of the epitaxial structure 120 and optionally also covers the sidewalls of the epitaxial structure 120 to protect it from damage by moisture, dust, and other impurities. An electrode structure is also formed above the epitaxial structure 120. The aforementioned protective layer 130 covers either the sidewalls of the electrode structure or a portion of the upper surface of the electrode structure, thus protecting the electrode structure while simultaneously exposing its upper surface for subsequent soldering of the light-emitting element 100. Figure 1 As shown, the electrode structure includes a first electrode 140 and a second electrode 150. The first electrode 140 is electrically connected to the first semiconductor layer structure 121, for example, forming an ohmic contact with an N-type AlGaN layer. The second electrode 150 is electrically connected to the second semiconductor layer structure 123, for example, through an ohmic contact layer 1231.

[0055] Refer again Figure 1In this embodiment, the light-emitting element 100 may further include a substrate 110, with the epitaxial structure 120 located above the substrate. The epitaxial structure 120 may be formed directly from the substrate 110, or it may be transferred above the substrate after growth on the growth substrate. The substrate 110 may be an insulating substrate or a conductive substrate. In optional embodiments, the substrate 110 is a growth substrate for epitaxial growth of semiconductor epitaxial stacks, including sapphire (Al2O3), SiC substrates, Si substrates, etc. The substrate 110 includes a first surface and a second surface disposed opposite to each other. The substrate 110 is a patterned substrate with micropatterns on the first surface. This patterned substrate is beneficial for the growth of the epitaxial structure 120 and can reduce the number of dislocations in the epitaxial structure 120, thereby improving the crystal quality of the epitaxial structure 120.

[0056] In an optional embodiment of this invention, the first semiconductor layer structure 121 may further include a bottom layer located between the N-type AlGaN layer and the substrate. This bottom layer includes a u-type AlN layer and a u-type AlGaN layer. These AlN and AlGaN layers can effectively alleviate the stress generated during the growth of the N-type AlGaN layer, which is beneficial for obtaining a high-quality epitaxial structure 120. It is understood that, in order to enable the flip-chip light-emitting diode of this embodiment to emit light from the substrate side, a reflective structure, such as a DBR structure, is also formed on the P-type semiconductor layer side. The aforementioned protective layer 130 may also be a reflective insulating material layer.

[0057] Example 2

[0058] This embodiment provides a light-emitting device, such as... Figure 6 As shown, the light-emitting device 200 includes a substrate 201 and a light-emitting element 202 disposed on the substrate 201, wherein the light-emitting element 202 can be the light-emitting element provided in Embodiment 1 of this application. The substrate 201 can be a packaging substrate or a circuit board connected to an external power supply. The light-emitting device 200 can be configured as a sterilization and disinfection device.

[0059] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A semiconductor light-emitting element, characterized in that, The semiconductor light-emitting element includes at least one epitaxial structure, which includes at least a first semiconductor layer structure, an active layer, and a second semiconductor layer structure stacked from bottom to top, wherein the active layer includes Al. y Ga 1-y N-barrier layer and Al x Ga 1-x An N-well layer, wherein 0 < x < 1, 0 < y < 1, and the second semiconductor layer structure includes Al. a Ga 1-a N material layer, where 0 < a < 1, and the second semiconductor layer structure is a P-type doped layer; Using the upper surface of the second semiconductor layer structure as a depth reference point, along the depth direction toward the active layer, the concentration of P-type dopant in the second semiconductor layer structure sequentially forms a first abrupt drop region L1, a gradual rise region L2, and a steep rise region L3 within the second semiconductor layer structure. A second abrupt drop region L4 is formed at the interface between the second semiconductor layer structure and the active layer. The slope of the P-type dopant concentration decrease in the second abrupt drop region L4 is greater than that in the first abrupt drop region L1, and the concentration of P-type dopant in the active layer decreases to 1×10⁻⁶. 16 atom / cm 3 .

2. The semiconductor light-emitting element according to claim 1, characterized in that, The second semiconductor layer structure is a P-type doped layer, wherein the concentration of P-type dopant is greater than 1 × 10⁻⁶. 17 atom / cm 3 .

3. The semiconductor light-emitting element according to claim 1, characterized in that, The thickness of the second semiconductor layer structure is less than or equal to 200 nm.

4. The semiconductor light-emitting element according to claim 1, characterized in that, The Al a Ga 1-a The thickness of the N material layer is less than or equal to 200 nm.

5. The semiconductor light-emitting element according to claim 1, characterized in that, The Al a Ga 1-a The thickness of the N material layer accounts for 60%-100% of the thickness of the second semiconductor layer structure.

6. The semiconductor light-emitting element according to claim 1, characterized in that, The second semiconductor layer structure may include an Al-free nitride material layer, wherein the thickness of the Al-free nitride material layer is less than or equal to 10 nm.

7. The semiconductor light-emitting element according to claim 6, characterized in that, The thickness of the Al-free nitride material layer is less than or equal to 5 nm.

8. The semiconductor light-emitting element according to claim 6, characterized in that, In the Al-free nitride material layer, the concentration of p-type dopant is greater than 5 × 10⁻⁶. 17 atom / cm 3 .

9. The semiconductor light-emitting element according to claim 6, characterized in that, The Al-free nitride material layer is located in the Al a Ga 1-a Above the N material layer.

10. The semiconductor light-emitting element according to claim 6, characterized in that, The Al a Ga 1-a The thickness of the N material layer is greater than the thickness of the Al-free nitride material layer.

11. The semiconductor light-emitting element according to claim 6, characterized in that, The Al a Ga 1-a The thickness of the N material layer is at least twice the thickness of the Al-free nitride material layer.

12. The semiconductor light-emitting element according to claim 1, characterized in that, The quantum well of the active layer is an In-free material layer.

13. The semiconductor light-emitting element according to claim 1, characterized in that, The P-type dopant is magnesium atoms.

14. The semiconductor light-emitting element according to claim 1, characterized in that, The emission wavelength of the active layer is between 220 nm and 410 nm.

15. The semiconductor light-emitting element according to claim 1, characterized in that, The emission wavelength of the active layer is between 240 nm and 370 nm.

16. A light-emitting device, characterized in that, It includes a circuit board and a light-emitting element disposed on the circuit board, wherein the light-emitting element comprises the semiconductor light-emitting element according to any one of claims 1 to 15.

Images