A semiconductor light emitting element and a light emitting device

Abstract

This invention provides a semiconductor light-emitting element and a light-emitting device. The epitaxial structure of the light-emitting element includes at least a first semiconductor layer structure, an active layer, and a second semiconductor layer structure stacked from bottom to top. The active layer includes Al. y Ga 1‑y N-barrier layer and Al x Ga 1‑x An N-type quantum well layer is formed, where 0 < x < 1 and 0 < y < 1. The second semiconductor layer is a P-type doped layer, in which the P-type dopant diffuses from the second semiconductor layer towards the active layer. Furthermore, the concentration of the P-type dopant is less than 5 × 10⁻⁶ at the first quantum well near the active layer of the second semiconductor layer. 19 atom / cm 3 By controlling the diffusion depth and concentration of Mg atoms, almost no Mg atoms diffuse from the P-type layer are present in the active layer. This effectively reduces the influence of Mg atoms on the MQW, improves the quality of the MQW, and consequently increases the recombination efficiency of electrons and holes in the active layer, thereby improving the internal quantum efficiency of the epitaxial layer and achieving high luminous efficiency of the light-emitting element.

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 internal quantum efficiency is the diffusion of magnesium (Mg) atoms into the multiple quantum wells (MQWs), which affects the MQW quality and leads to a decrease in the luminous efficiency of the active layer. Mg atoms diffuse partially through the plane and material defects (V-pits). While existing technologies can reduce electron overflow by improving the epitaxial layer structure, the blocking effect on electrons decreases with increasing current density, thus affecting the electron-hole recombination efficiency. To effectively improve the internal quantum efficiency of the epitaxial layer and achieve high luminous efficiency in LEDs, it is necessary to provide a scheme that can effectively control and regulate the diffusion of Mg atoms. 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 to solve one or more of the above problems.

[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-type quantum well layer is provided, where 0 < x < 1 and 0 < y < 1. The second semiconductor layer structure is a P-type doped layer, wherein the P-type dopant diffuses towards the active layer, and the concentration of the P-type dopant is less than 5 × 10⁻⁶ at the first quantum well of the active layer near the second semiconductor layer structure. 19 atom / cm 3 .

[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 P-type dopant in the second semiconductor layer structure diffuses from the second semiconductor layer structure toward the active layer, and the concentration of the P-type dopant is less than 5 × 10⁻⁶ at the first quantum well near the active layer of the second semiconductor layer structure. 19 atom / cm 3 This results in almost no Mg atoms diffusing from the P-type layer in the active layer. By controlling the diffusion depth and concentration range of Mg atoms, the recombination efficiency of electrons and holes in the active layer can be improved, the internal quantum efficiency of the epitaxial layer can be increased, and high luminous efficiency of the light-emitting diode can be achieved. Attached Figure Description

[0009] Figure 1 The diagram shown is a schematic diagram of the structure 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 Displayed as Figure 1 A schematic diagram of the concentration distribution of different elements in each layer of the epitaxial structure.

[0012] Figure 4 The diagram shown is a schematic diagram of the light-emitting device provided in Embodiment 2 of this application.

[0013] Component designation explanation

[0014] 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, Electron blocking layer; 124, Second semiconductor layer structure; 130, Protective layer; 140, First electrode; 150, Second electrode; 200, Light-emitting device; 201, Circuit board; 202, Light-emitting element. Detailed Implementation

[0015] 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.

[0016] 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.

[0017] 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-type quantum well layer is provided, where 0 < x < 1 and 0 < y < 1. The second semiconductor layer structure is a P-type doped layer, wherein the P-type dopant diffuses towards the active layer, and the concentration of the P-type dopant is less than 5 × 10⁻⁶ at the first quantum well of the active layer near the second semiconductor layer structure. 19 atom / cm 3 .

[0018] Optionally, the active layer is a multiple quantum well structure, comprising p Al atoms. y Ga 1-y N barrier layers and q Al x Ga 1-x N-potential well layer, the Al y Ga 1-y N-barrier layer and Al x Ga 1-x The N-potential well layers are arranged alternately, where p≥1 and q≥1.

[0019] Optionally, the quantum well of the active layer is an In-free material layer.

[0020] Optionally, the concentration of the p-type dopant is less than 1 × 10⁻⁶. 19 atom / cm 3 .

[0021] By controlling the concentration of the P-type dopant, there are almost no P-type dopants, such as Mg atoms, diffused from the second semiconductor layer in the active layer. This can improve the recombination efficiency of electrons and holes in the active layer, increase the internal quantum efficiency of the epitaxial layer, and achieve high luminous efficiency of the light-emitting diode.

[0022] Optionally, the depth to which the P-type dopant diffuses into the active layer does not exceed two quantum wells.

[0023] Optionally, in the first quantum well closest to the second semiconductor layer structure, the concentration of the p-type dopant is no greater than 1 × 10⁻⁶. 19 atom / cm 3 .

[0024] Optionally, in the active layer, the concentration of the P-type dopant is less than 1 × 10⁻⁶. 19 atom / cm 3 .

[0025] By controlling the diffusion depth of P-type dopants and further controlling the diffusion concentration range of P-type dopants in the active layer, it is possible to make the active layer almost free of P-type dopants diffused from the second semiconductor layer structure, such as Mg atoms. Alternatively, a small amount of P-type dopants can be present only in the one or two quantum wells closest to the second semiconductor layer structure. This can improve the recombination efficiency of electrons and holes in the active layer, increase the internal quantum efficiency of the epitaxial layer, and achieve high luminous efficiency in light-emitting diodes.

[0026] Optionally, in the second quantum well closest to the second semiconductor layer structure, the concentration of the P-type dopant is no greater than 1 × 10⁻⁶. 18 atom / cm 3 .

[0027] Optionally, the quantum well closest to the second semiconductor layer structure is defined as the first quantum well, and starting from the fifth quantum well from the second semiconductor layer structure, the concentration of the P-type dopant ranges from less than 1 × 10⁻⁶. 17 atom / cm 3 .

[0028] As shown above, only one or two quantum wells, or fewer than five, closest to the second semiconductor layer structure contain a small amount of P-type dopant. After the fifth quantum well, the active layer contains almost no P-type dopant, thereby improving the recombination efficiency of electrons and holes in the active layer, increasing the internal quantum efficiency of the epitaxial layer, and achieving high luminous efficiency of the light-emitting diode.

[0029] Optionally, an electron blocking layer is further formed between the active layer and the second semiconductor layer structure, and the concentration of the p-type dopant in the electron blocking layer is between 1 × 10⁻⁶. 18 atom / cm 3 ~1×10 20 atom / cm 3 .

[0030] Controlling the concentration of P-type dopant in the electron blocking layer helps to control the concentration of P-type dopant near the active layer, making the concentration of P-type dopant in the active layer low enough to increase the electron-hole recombination efficiency.

[0031] Optionally, from the second semiconductor layer structure to the active layer, the concentration of the P-type dopant forms a drop region, and in the drop region, the diffusion depth of the P-type dopant does not exceed two quantum wells.

[0032] By controlling the diffusion depth of P-type dopants in the active layer, the quantum wells other than the first quantum well near the second semiconductor layer or the first and second quantum wells are free of diffused P-type dopants, thereby ensuring the electron-hole recombination efficiency.

[0033] Optionally, the drop-off region has a first drop-off region and a second drop-off region, the first drop-off region being formed in the electron blocking layer and the second drop-off region being formed in the active layer, wherein the concentration of the p-type dopant in the first drop-off region is between 1 × 10⁻⁶. 18 atom / cm 3 ~1×10 20 atom / cm 3 In the second drop region, the concentration of the P-type dopant ranges from 1 × 10⁻⁶. 17 atom / cm 3 ~1×10 19 atom / cm 3 .

[0034] Optionally, the rate of decrease of the P-type dopant concentration in the second drop region is greater than the rate of decrease of the P-type dopant concentration in the first drop region.

[0035] The drop-off region of the P-type dopant is divided into a first drop-off region in the electron blocking layer and a second drop-off region in the active layer. The concentration of P-type dopant in the first drop-off region and the second drop-off region are controlled respectively. This allows for better control of the diffusion concentration and diffusion depth of P-type dopant in the active layer, ensuring that there are no excess diffused P-type dopant in the active layer. Furthermore, by controlling the drop slope of the second drop-off region to be greater than that of the first drop-off region, the concentration of P-type dopant in the active layer can be kept sufficiently low, thereby increasing the electron-hole recombination efficiency.

[0036] Optionally, in the active layer, the number of pairs of potential well layers and potential barrier layers is between 3 and 15, and the concentration of the p-type dopant is greater than 1 × 10⁻⁶. 18 atom / cm 3 The number of logarithms of the material layers is less than or equal to 2.

[0037] Optionally, a buffer zone is further formed between the first and second steep drop regions. The concentration of the P-type dopant in the buffer zone increases from the first steep drop region to the second steep drop region, and the concentration of the P-type dopant is between 1 × 10⁻⁶.18 atom / cm 3 ~1×10 19 atom / cm 3 .

[0038] Optionally, the buffer is formed in the electron blocking layer.

[0039] Optionally, before the buffer zone enters the second drop region, the P-type dopant has a concentration peak, and at the peak position of the P-type dopant concentration peak, the doping concentration of the P-type dopant is between 5 × 10⁻⁶. 18 atom / cm 3 ~5×10 19 atom / cm 3 .

[0040] The concentration of P-type contaminants in the buffer zone increases slightly and then levels off, before entering the second rapid decrease zone and continuing to drop sharply. The formation of the buffer zone helps to better control the concentration of P-type contaminants in the active layer.

[0041] Optionally, the P-type dopant is a magnesium atom.

[0042] Optionally, the emission wavelength of the active layer is between 240 nm and 410 nm.

[0043] In ultraviolet light-emitting diodes that radiate the above wavelength range, limiting the diffusion depth and concentration of Mg atoms can effectively improve the electron-hole recombination efficiency in the active layer and thus improve the light extraction efficiency.

[0044] 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.

[0045] Example 1

[0046] This embodiment provides a semiconductor light-emitting element (also known as an LED, light-emitting diode), such as... Figure 1As 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 124 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.

[0047] The first semiconductor layer structure 121 described above can be an N-type layer, and correspondingly, the second semiconductor layer structure 124 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 124 can be a P-type layer.

[0048] 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.

[0049] 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 .

[0050] In this embodiment, as Figure 3 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-x The 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 240 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, good crystal growth quality, and few dislocations or micropit 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 240 nm and 410 nm, and more specifically, between 260 nm and 380 nm.

[0051] The second semiconductor layer structure 124 is a p-type AlGaN layer or a GaN layer, which provides holes by doping with p-type impurities. The p-type impurities can be Mg, Zn, Ca, Sr, and Ba. In this embodiment, Mg is preferred as the p-type impurity. In optional embodiments, such as... Figure 3 As shown, the doping concentration of Mg in the second semiconductor layer structure 124 is greater than or equal to 1 × 10⁻⁶. 19 atom / cm3 And less than or equal to 1×10 21 atom / cm 3 It is understandable that an ohmic contact layer can also be formed above the second semiconductor layer structure 124, through high doping, for example, a doping concentration higher than 1×10⁻⁶. 20 atoms / cm 3 This forms an ohmic contact with the subsequently formed P-type electrode. The thickness of the second semiconductor layer structure 124 is 5 nm or more, more preferably 100 nm or less, to ensure that the P-type GaN layer can improve the defects in the epitaxial structure 120, thereby improving the reliability of the nitride light-emitting diode.

[0052] like Figure 3 As shown, in this embodiment, Mg atoms in the second semiconductor layer structure 124 diffuse from the second semiconductor layer structure 124 toward the active layer 122, and the concentration of Mg atoms is less than 5 × 10⁻⁶ near the active layer 122. 19 atom / cm 3 Furthermore, below 1×10 19 atom / cm 3 Furthermore, the diffusion depth of Mg atoms into the active layer 122 does not exceed 3-5 quantum wells; further, it does not exceed two quantum wells; even further, it does not exceed one quantum well, meaning that the entire active layer contains almost no Mg atoms. In this embodiment, the quantum well of the active layer 122 near the side of the second semiconductor layer structure 124 is defined as the first quantum well, and within the thickness range of the first quantum well, the concentration of Mg atoms is less than 1×10⁻⁶. 19 atom / cm 3 In the second quantum well, which is closest to the second semiconductor layer structure, the concentration of Mg atoms is no greater than 1 × 10⁻⁶. 18 atom / cm 3 Furthermore, in the remaining quantum wells after the first quantum well of the active layer 122, there are almost no Mg atoms diffused from the second semiconductor layer structure 124. In another alternative embodiment, the active layer includes n quantum wells, n≥5, and the concentration of Mg atoms is less than 1×10 from the fifth quantum well of the second semiconductor layer structure. 17 atom / cm 3 .Although Figure 3 The results show that there is a Mg atom signal in the active layer 122. This Mg atom signal is usually an unintentionally doped Mg atom impurity signal, i.e., a noise signal in the test.

[0053] Similarly, Figure 1As shown, an electron barrier layer (EBL) 123 is formed between the active layer 122 and the second semiconductor layer structure 124. In an optional embodiment of this example, the electron barrier layer 123 is an Al-containing nitride layer, and more specifically, an Al-containing gallium nitride layer. Furthermore, the Al content is above 60%, and more specifically, between 60% and 100%, and even more specifically, controlled between 75% and 90%. The higher Al content in the electron barrier layer 123 is beneficial for preventing the diffusion of Mg atoms from the P-type semiconductor layer into the active layer 122, and is beneficial for improving the recombination efficiency of electrons and holes in the active layer 122. In an optional embodiment, the electron barrier layer 123 is a U-type AlGaN layer, such as... Figure 3 As shown, in an optional embodiment, the thickness of the electron blocking layer 123 is between 5 nm and 200 nm; in a further embodiment, the thickness of the electron blocking layer 123 is between 5 nm and 100 nm. This thickness ensures sufficient obstruction of Mg atom diffusion. Figure 3 As shown, under the action of the electron blocking layer 123, Mg atoms in the epitaxial structure 120 diffuse only in the P-type semiconductor layer and will not diffuse to the electron blocking layer 123, let alone diffuse to the active layer 122 via the electron blocking layer 123. Therefore, this is beneficial to improving the electron-hole recombination efficiency of the active layer 122 and improving the internal quantum efficiency. In an optional embodiment, the electron blocking layer 123 is Al. a Ga (1-a) N layers, where 0 < a ≤ 1. Electron blocking layers 123 can be single-layer or multi-layer structures.

[0054] like Figure 3 As shown, when P-type dopant Mg atoms diffuse from the second semiconductor layer structure 124 to the active layer 122, a concentration drop region is formed. Within this drop region, the diffusion depth of the P-type dopant does not exceed two quantum wells; that is, the diffusion depth of Mg atoms in the drop region does not exceed the second quantum well of the active layer 122. Further, when Mg atoms diffuse from the second semiconductor layer structure 124 to the active layer 122, they first diffuse to the electron blocking layer 123. In an optional embodiment, the concentration of Mg atoms in the electron blocking layer 123 is between 1 × 10⁻⁶. 18 atom / cm 3 ~1×10 20 atom / cm 3 .

[0055] In optional embodiments, such as Figure 2 As shown, the abrupt drop region has a first abrupt drop region L1 and a second abrupt drop region L2. The first abrupt drop region L1 is formed in the electron blocking layer 123. In the first abrupt drop region L1, the concentration of Mg atoms ranges from 1×10⁻⁶. 18 atom / cm3 ~1×10 20 atom / cm 3 The second drop region L2 forms at the boundary between the electron blocking layer 123 and the active layer 122. In the second drop region L2, the concentration of Mg atoms ranges from 1 × 10⁻⁶. 17 atom / cm 3 ~1×10 19 atom / cm 3 Dividing the abrupt drop region into a first abrupt drop region L1 and a second abrupt drop region L2 is beneficial for controlling the depth of Mg atoms in the active layer 122, that is, for controlling the diffusion depth of Mg atoms to no more than two, and further, no more than one quantum well. By controlling the diffusion depth and diffusion concentration of Mg atoms in the quantum well, the recombination efficiency of electrons and holes in the active layer 122 can be improved, the internal quantum efficiency of the epitaxial layer can be improved, and high luminous efficiency of the light-emitting diode can be achieved. Furthermore, as... Figure 3 As shown, the rate of decrease in Mg atom doping concentration in the second steep drop region is greater than that in the first steep drop region. This allows for further control of the P-type dopant (Mg atom) concentration in the active layer to be sufficiently low, thereby increasing the electron-hole recombination efficiency.

[0056] In alternative embodiments, the same applies. Figure 3 As shown, a buffer zone L3 is also formed between the first steep-descent region L1 and the second steep-descent region L2. This buffer zone L3 is formed in the electron blocking layer 123, and further, the buffer zone L3 is formed within a range of approximately 60 nm from the surface of the active layer 122. In the buffer zone, the concentration of Mg atoms is between 1 × 10⁻⁶. 18 atom / cm 3 ~5×10 19 atom / cm 3 That is, during the rapid decrease in Mg atom concentration, the Mg atom concentration increases slightly in buffer zone L3, and then tends to level off within this buffer zone L3. Afterwards, in the second rapid decrease zone L2, the Mg atom concentration continues to decrease rapidly. The formation of buffer zone L3 facilitates better control of the Mg atom concentration in active layer 122.

[0057] The aforementioned diffusion characteristics of Mg atoms from the second semiconductor layer structure 124 to the active layer 122 can effectively reduce the influence of Mg atoms on the MQW, improve the quality of the MQW, and thus improve the recombination efficiency of electrons and holes in the active layer 122, improve the internal quantum efficiency of the epitaxial layer, and achieve high luminous efficiency of the light-emitting diode.

[0058] In optional embodiments, such as Figure 2As shown, before entering the second drop zone L2 from buffer zone L3, the Mg atom diffusion concentration forms a concentration peak. At the peak position of this concentration peak, the Mg atom doping concentration is between 5 × 10⁻⁶. 18 atom / cm 3 ~5×10 19 atom / cm 3 Controlling this peak concentration is beneficial for controlling the diffusion concentration of Mg atoms in the second drop region L2 and the diffusion depth in the active layer 122.

[0059] 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 124, for example, through an ohmic contact layer.

[0060] Refer again Figure 1 In this embodiment, the light-emitting element 100 may further include a substrate 110, which may be an insulating substrate or a conductive substrate. In optional embodiments, the substrate 110 is a growth substrate for epitaxial growth of a semiconductor epitaxial stack, including sapphire (Al2O3), SiC substrate, Si substrate, 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 facilitates 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.

[0061] 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.

[0062] Example 2

[0063] This embodiment provides a light-emitting device, such as... Figure 4 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. The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes 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. The active layer is a multiple quantum well structure, comprising Al... y Ga 1-y N-barrier layer and Al x Ga 1-x An N-type quantum well layer is defined, where 0 < x < 1 and 0 < y < 1. The quantum well of the active layer is an In-free material layer. The second semiconductor layer is a P-type doped layer, wherein the P-type dopant diffuses from the second semiconductor layer towards the active layer, and the concentration of the P-type dopant is less than 5 × 10⁻⁶ near the interface between the second semiconductor layer and the active layer. 19 atom / cm 3 The p-type dopant diffuses into the active layer to a depth of no more than two quantum wells, and the concentration of the p-type dopant in the first quantum well closest to the second semiconductor layer structure is no greater than 1 × 10⁻⁶. 19 atom / cm 3 .

2. The semiconductor light-emitting element according to claim 1, characterized in that, The active layer includes p Al atoms. y Ga 1-y N barrier layers and q Al x Ga 1-x N-potential well layer, the Al y Ga 1-y N-barrier layer and Al x Ga 1-x The N potential well layers are arranged alternately, where p≥2 and q≥2.

3. The semiconductor light-emitting element according to claim 1, characterized in that, The concentration of the P-type dopant is less than 1 × 10⁻⁶. 19 atom / cm 3 .

4. The semiconductor light-emitting element according to claim 1, characterized in that, In the active layer, the concentration of the P-type dopant is less than 1 × 10⁻⁶. 19 atom / cm 3 .

5. The semiconductor light-emitting element according to claim 1, characterized in that, In the second quantum well closest to the second semiconductor layer structure, the concentration of the P-type dopant is no greater than 1 × 10⁻⁶. 18 atom / cm 3 .

6. The semiconductor light-emitting element according to claim 1, characterized in that, The quantum well closest to the second semiconductor layer structure is defined as the first quantum well. Starting from the fifth quantum well from the second semiconductor layer structure, the concentration of the p-type dopant is less than 1 × 10⁻⁶. 17 atom / cm 3 .

7. The semiconductor light-emitting element according to claim 1, characterized in that, An electron blocking layer is further formed between the active layer and the second semiconductor layer structure, and the concentration of the P-type dopant in the electron blocking layer is between 1 × 10⁻⁶. 18 atom / cm 3 ~1×10 20 atom / cm 3 .

8. The semiconductor light-emitting element according to claim 7, characterized in that, From the second semiconductor layer structure to the active layer, the concentration of the P-type dopant forms a drop region, and in the drop region, the diffusion depth of the P-type dopant does not exceed two quantum wells.

9. The semiconductor light-emitting element according to claim 8, characterized in that, The drop-off region comprises a first drop-off region and a second drop-off region. The first drop-off region is formed in the electron blocking layer, and the second drop-off region is formed in the active layer. In the first drop-off region, the concentration of the p-type dopant ranges from 1 × 10⁻⁶. 18 atom / cm 3 ~1×10 20 atom / cm 3 In the second drop region, the concentration of the P-type dopant ranges from 1 × 10⁻⁶. 17 atom / cm 3 ~1×10 19 atom / cm 3 .

10. The semiconductor light-emitting element according to claim 9, characterized in that, The slope of the decrease in P-type dopant concentration in the second drop region is greater than the slope of the decrease in P-type dopant concentration in the first drop region.

11. The semiconductor light-emitting element according to claim 8, characterized in that, In the active layer, the number of pairs of potential well layers and potential barrier layers is between 3 and 15, and the concentration of the p-type dopant is greater than 1 × 10⁻⁶. 18 atom / cm 3 The number of logarithms of the material layers is less than or equal to 2.

12. The semiconductor light-emitting element according to claim 9, characterized in that, A buffer zone is also formed between the first and second rapid descent regions. The concentration of the P-type dopant in the buffer zone increases from the first rapid descent region to the second rapid descent region, and the concentration of the P-type dopant is between 1 × 10⁻⁶. 18 atom / cm 3 ~5×10 19 atom / cm 3 .

13. The semiconductor light-emitting element according to claim 12, characterized in that, The buffer zone is formed in the electron blocking layer.

14. The semiconductor light-emitting element according to claim 12, characterized in that, Before entering the second drop region in the buffer zone, there is a P-type dopant concentration peak, and at the peak position of the P-type dopant concentration peak, the doping concentration of the P-type dopant is between 5 × 10⁻⁶. 18 atom / cm 3 ~5×10 19 atom / cm 3 .

15. The semiconductor light-emitting element according to any one of claims 1 to 14, characterized in that, The P-type dopant is magnesium atoms.

16. The semiconductor light-emitting element according to claim 15, characterized in that, The emission wavelength of the active layer is between 240 nm and 410 nm.

17. 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 16.

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