An LED chip

Abstract

The application discloses an LED chip, and relates to the technical field of light-emitting diodes, which comprises an epitaxial stack and a light-selective transmission layer located on the light-emitting surface side of the epitaxial stack, wherein the light-selective transmission layer comprises a transparent insulating layer and a metal nano-pattern layer embedded in the transparent insulating layer; the metal nano-pattern layer forms a surface plasmon structure; and the resonance wavelength range of the surface plasmon structure matches the target wavelength range of the light emitted by an active layer. When the light with the target wavelength range emitted by the active layer irradiates the metal nano-pattern layer, the plasmon on the surface of the metal nano-pattern layer resonates with the light with the target wavelength range emitted by the active layer. The resonance selectively and strongly enhances the transmission of the light with the target wavelength range emitted by the active layer and suppresses the transmission of the light with a non-resonance wavelength range, thereby effectively narrowing the light spectrum width of the LED chip, improving the color purity of the LED chip, and increasing the light extraction rate of the LED chip.

Description

Technical Field

[0001] This application relates to the field of light-emitting diode technology, and more particularly to an LED chip. Background Technology

[0002] Light-emitting diodes (LEDs), as a highly efficient solid-state light source, have been widely used in display, lighting and other fields. In display applications, the color gamut of a display screen packaged with red, green and blue (RGB) LEDs directly depends on the color purity of each LED chip. The higher the color purity, the wider the color gamut and the more vivid and realistic the colors.

[0003] Currently, for LED chips on the market, regardless of whether they are upright, flip-chip, or vertically mounted, the half-width of their emitted light spectrum is mainly determined by the active layer in the epitaxial structure. Due to the spontaneous polarization and piezoelectric polarization effects of the active layer, the energy band of the active layer is tilted, resulting in a certain range of wavelengths in the spectrum emitted by the LED chip. An excessively wide spectral distribution will directly lead to a decrease in the color purity of the LED chip.

[0004] Therefore, how to effectively narrow the light emission spectrum width of LED chips and improve the color purity of LED chips, thereby improving the display color gamut of the display screen, while maintaining the luminous efficiency of LED chips, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides an LED chip that effectively narrows the emission spectrum width of the LED chip while maintaining its luminous efficiency, thereby improving the color purity of the LED chip and ultimately enhancing the display color gamut of the screen.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] An LED chip, comprising:

[0008] An epitaxial stack, wherein the epitaxial stack comprises a first type semiconductor layer, an active layer, and a second type semiconductor layer stacked together;

[0009] A light selective transmission layer is located on the light-emitting surface side of the epitaxial stack. The light selective transmission layer includes a transparent insulating layer and a metal nanopattern layer embedded in the transparent insulating layer. The metal nanopattern layer constitutes a surface plasmon structure. The resonant wavelength range of the surface plasmon structure matches the target wavelength range of the light emitted by the active layer.

[0010] Optionally, the metal nanopattern layer comprises an array of metal nanoparticles.

[0011] Optionally, the shape of the metal nanoparticles can be any one or more of the following: nanopillars, nanocones, nanohemisphericals, cuboid nanostructures, polygonal nanostructures, and U-shaped nanostructures.

[0012] Optionally, the light in the target wavelength range is green light, and the material of the metal nanoparticles includes at least one of silver and gold.

[0013] Optionally, the light in the target wavelength range is green light;

[0014] The metal nanoparticles are shaped like nanopillars, and the diameter of the metal nanoparticles ranges from 50 nm to 150 nm, including the endpoint values.

[0015] The spacing between adjacent metal nanoparticles ranges from 100 nm to 300 nm, including the endpoint values.

[0016] Optionally, the transmittable wavelength range of the light selective transmission layer is ±20 nm of the target wavelength range of the light emitted by the active layer, including the endpoint values.

[0017] Optionally, the LED chip has a vertical structure;

[0018] The LED chip also includes:

[0019] First substrate;

[0020] The first bonding layer located on one side of the first substrate;

[0021] The epitaxial stack is located on the side of the first bonding layer away from the first substrate. In the epitaxial stack, the first type semiconductor layer, the active layer and the second type semiconductor layer are stacked in a direction away from the first substrate. A first reflective layer is also disposed between the epitaxial stack and the first bonding layer.

[0022] A first electrode located on the side of the first substrate opposite to the first bonding layer, and a second electrode located on the side of the second type semiconductor layer opposite to the first substrate;

[0023] The light selective transmission layer is located on the side of the epitaxial stack facing away from the first substrate. The light selective transmission layer covers the sidewall of the epitaxial stack, the surface of the epitaxial stack facing away from the first substrate, and the sidewall of the second electrode, and exposes at least a portion of the second electrode.

[0024] Optionally, the LED chip has a vertical structure with electrodes on the same side;

[0025] The LED chip also includes:

[0026] Second substrate;

[0027] The second bonding layer is located on one side of the second substrate;

[0028] The epitaxial stack is located on the side of the second bonding layer away from the second substrate. In the epitaxial stack, the second type semiconductor layer, the active layer, and the first type semiconductor layer are stacked in a direction toward the second substrate. The epitaxial stack has a first groove on the side toward the second substrate, and the first groove exposes a portion of the second type semiconductor layer.

[0029] A second reflective layer, an anti-diffusion layer, a first insulating layer, and a connecting metal layer are disposed between the epitaxial stack and the second bonding layer. The second reflective layer is located on the side of the epitaxial stack facing the second substrate. The anti-diffusion layer covers the second reflective layer. The first insulating layer covers the anti-diffusion layer, the surface of the epitaxial stack facing the second substrate, and the sidewall of the first groove. The connecting metal layer is located between the first insulating layer and the second bonding layer, and the connecting metal layer fills the first groove and is electrically connected to the second type semiconductor layer.

[0030] The epitaxial stack also has a second groove on the side away from the second substrate, the second groove exposes the anti-diffusion layer, a first electrode is disposed on the anti-diffusion layer, and a second electrode is disposed on the side of the second substrate away from the second bonding layer;

[0031] The light selective transmission layer is located on the side of the epitaxial stack facing away from the second substrate. The light selective transmission layer covers the sidewall of the epitaxial stack, the surface of the epitaxial stack facing away from the second substrate, and the sidewall of the first electrode, and exposes at least a portion of the first electrode.

[0032] Optionally, the LED chip has a front-mounted structure;

[0033] The LED chip also includes:

[0034] Third substrate;

[0035] The epitaxial stack is located on one side of the third substrate. In the epitaxial stack, the second type semiconductor layer, the active layer, and the first type semiconductor layer are stacked in a direction away from the third substrate. The epitaxial stack has a third groove on the side away from the third substrate, and the third groove exposes a portion of the second type semiconductor layer.

[0036] A first transparent conductive layer is located on the side of the first type semiconductor layer opposite to the third substrate, and the first transparent conductive layer has a first through-hole;

[0037] A first electrode and a second electrode, wherein the first electrode is located on the side of the first type semiconductor layer away from the third substrate and is electrically connected to the first type semiconductor layer through the first via; the second electrode is located on the second type semiconductor layer exposed in the third groove and is electrically connected to the second type semiconductor layer.

[0038] The light selective transmission layer is located on the side of the first transparent conductive layer away from the third substrate. The light selective transmission layer covers the sidewalls of the epitaxial stack, the surface of the transparent conductive layer away from the third substrate, and the sidewalls of the first electrode and the second electrode, and exposes at least a portion of the first electrode and at least a portion of the second electrode.

[0039] Optionally, the LED chip has a flip-chip structure;

[0040] The LED chip also includes:

[0041] Fourth substrate;

[0042] The epitaxial stack is located on one side of the fourth substrate. In the epitaxial stack, the second type semiconductor layer, the active layer, and the first type semiconductor layer are stacked in a direction away from the fourth substrate. The epitaxial stack has a fourth groove on the side away from the fourth substrate, and the fourth groove exposes a portion of the second type semiconductor layer.

[0043] A second transparent conductive layer located on the side of the first type semiconductor layer facing away from the fourth substrate;

[0044] A first electrode located on the side of the second transparent conductive layer opposite to the fourth substrate, and a second electrode located on the second type semiconductor layer exposed in the fourth groove;

[0045] The light selective transmission layer is located on the side of the fourth substrate opposite to the epitaxial stack.

[0046] Compared with existing technologies, the above technical solution has the following advantages:

[0047] The LED chip provided in this application includes an epitaxial stack and a light selective transmission layer located on one side of the light-emitting surface of the epitaxial stack. The epitaxial stack includes a first-type semiconductor layer, an active layer, and a second-type semiconductor layer stacked together. The light selective transmission layer includes a transparent insulating layer and a metal nanopattern layer embedded within the transparent insulating layer. The metal nanopattern layer constitutes a surface plasmon structure, and the resonant wavelength range of the surface plasmon structure matches the target wavelength range of the light emitted by the active layer. That is, the resonant wavelength range of the surface plasmon structure at least partially overlaps with the target wavelength range of the light emitted by the active layer. Therefore, when light of the target wavelength range emitted by the active layer is emitted to the metal nanopattern layer, the plasma on the surface of the metal nanopattern layer (such as...) Electrons resonate with light emitted from the active layer in the target wavelength range. This resonance selectively and strongly enhances the transmission of light in the target wavelength range emitted from the active layer, while suppressing the transmission of light in non-resonant wavelength ranges through reflection and / or absorption, thus filtering out long and short noise waves emitted by the active layer. In this way, the emission spectrum width of the LED chip can be effectively narrowed while maintaining the luminous efficiency of the LED chip, improving the color purity of the LED chip, and thus improving the display color gamut of the display screen. Furthermore, since the surface plasmon structure composed of the metal nanopattern layer can selectively enhance the transmission of light in the target wavelength range emitted from the active layer, the light extraction rate of the LED chip can also be improved, thereby improving the luminous efficiency of the LED chip.

[0048] Furthermore, by embedding a metal nanopattern layer within a transparent insulating layer to form a light-selective transmission layer located on one side of the light-emitting surface of the LED chip, the light-selective transmission layer can achieve highly selective filtering of light emitted from the active layer within a relatively thin film thickness, thus making the LED chip structure more compact. Moreover, the method of achieving highly selective filtering by forming a surface plasmon structure with the metal nanopattern layer is insensitive to the incident light angle, making it more suitable for divergent light sources like LED chips. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the light emission spectrum of a conventional green LED chip;

[0051] Figure 2 This is a cross-sectional structural diagram of an LED chip provided in an embodiment of this application;

[0052] Figure 3 This is a cross-sectional structural diagram of another LED chip provided in an embodiment of this application;

[0053] Figure 4 This is a cross-sectional structural diagram of another LED chip provided in an embodiment of this application;

[0054] Figure 5 This is a cross-sectional structural diagram of another LED chip provided in an embodiment of this application;

[0055] Figure 6 This is a partial top view of the light selective transmission layer in an LED chip provided in an embodiment of this application;

[0056] Figure 7 for Figure 6 The diagram shows a schematic representation of the light selective transmission layer along section AA'.

[0057] Figure 8 The reflectivity of the light selective transmission layer in an LED chip provided in this application for light of different wavelengths is shown.

[0058] Figure 9 This is a schematic diagram of the light emission spectrum of a green LED chip provided in an embodiment of this application.

[0059] Explanation of reference numerals in the attached figures:

[0060] Epitaxial stack 10; first type semiconductor layer 11; active layer 12; second type semiconductor layer 13; light selective transmission layer 20; transparent insulating layer 21; metal nanopattern layer 22; metal nanoparticles 220; first substrate 101; first bonding layer 102; first reflective layer 103; first electrode T1; second electrode T2; second substrate 201; second bonding layer 202; first groove U1; second reflective layer 203; anti-diffusion layer 204; first insulating layer 205; connecting metal layer 206; second groove U2; third substrate 301; third groove U3; first transparent conductive layer 302; first via K1; fourth substrate 401; fourth groove U4; second transparent conductive layer 402; insulating reflective layer 403; first pad P1; second pad P2. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0063] Secondly, this application provides a detailed description in conjunction with schematic diagrams. When detailing the embodiments of this application, for ease of explanation, the accompanying drawings illustrating the device structure may be partially enlarged, not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this application. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0064] As described in the background section, due to the spontaneous polarization and piezoelectric polarization effects of the active layer, the energy band of the active layer is tilted, which causes the wavelength of the spectrum emitted by the LED chip to have a certain range. The excessively wide spectral distribution will directly lead to a decrease in the color purity of the LED chip.

[0065] Taking green LED chips as an example, Figure 1 A schematic diagram of the light emission spectrum of a conventional green LED chip is shown, such as... Figure 1 As shown, the half-width of the emitted light spectrum of conventional green LED chips is typically between 25nm and 30nm, with the wavelength of radiated photons distributed across a range of 50nm to 60nm. Due to the excessively wide spectral distribution, the color purity of conventional green LED chips can only reach approximately 85%. The problem of low color purity in green LED chips is particularly prominent and has become one of the key factors restricting the improvement of the color gamut of RGB displays.

[0066] To address the aforementioned issues, existing technologies primarily focus on optimizing the epitaxial structure to compress the half-width, such as adjusting the quantum well structure and doping concentration. However, due to limitations in the physical properties of the material system, relying solely on epitaxial optimization makes it difficult to significantly improve color purity while maintaining luminous efficiency. Additionally, there are technical solutions using dielectric filters for spectral filtering. However, traditional dielectric filters are typically composed of stacked layers of films with different refractive indices, resulting in a relatively thick structure and strong angle dependence, which limits their integration into LED chips.

[0067] Therefore, how to effectively narrow the light spectrum and improve color purity while maintaining the luminous efficiency of LED chips, thereby improving the display color gamut of the display screen, is a technical problem that urgently needs to be solved in this field.

[0068] In view of this, embodiments of this application provide an LED chip, such as... Figures 2-5 As shown, the LED chip includes an epitaxial stack 10 and a light selective transmission layer 20; wherein, the epitaxial stack 10 includes a first type semiconductor layer 11, an active layer 12 and a second type semiconductor layer 13 stacked together; the light selective transmission layer 20 is located on the light-emitting side of the epitaxial stack 10.

[0069] Optionally, the first type semiconductor layer 11 is an N-type semiconductor layer and the second type semiconductor layer 13 is a P-type semiconductor layer, or vice versa, the first type semiconductor layer 11 is a P-type semiconductor layer and the second type semiconductor layer 13 is an N-type semiconductor layer. The electrons and holes provided by the first type semiconductor layer 11 and the second type semiconductor layer 13 recombine and emit light within the active layer 12.

[0070] Figure 6 This diagram shows a partial top view of the light selective transmission layer 20 in an LED chip according to an embodiment of this application. Figure 7 It shows Figure 6 The diagram shown illustrates the structure of the light selective transmission layer 20 along section AA'. Figure 6 and Figure 7 As shown, the light selective transmission layer 20 includes a transparent insulating layer 21 and a metal nanopattern layer 22 embedded within the transparent insulating layer 21, i.e., the metal nanopattern layer 22 is sandwiched between the transparent insulating layer 21. In actual processes, a first sub-transparent insulating layer (a part of the transparent insulating layer 21) can be formed first, and then the metal nanopattern layer 22 can be formed on the first sub-transparent insulating layer through processes such as evaporation, imprinting, or etching. Subsequently, a second sub-transparent insulating layer (another part of the transparent insulating layer 21) covering the metal nanopattern layer 22 can be formed. Finally, the first and second sub-transparent insulating layers constitute the transparent insulating layer 21, and the transparent insulating layer 21 and the metal nanopattern layer 22 together constitute the light selective transmission layer 20.

[0071] The metal nanopattern layer 22 constitutes a surface plasmon structure, and the resonant wavelength range of the surface plasmon structure matches the target wavelength range of the light emitted by the active layer 12. That is, the resonant wavelength range of the surface plasmon structure and the target wavelength range of the light emitted by the active layer 12 at least partially overlap. Therefore, when the light of the target wavelength range emitted by the active layer 12 is emitted to the metal nanopattern layer 22, since the metal nanopattern layer 22 constitutes a surface plasmon structure, the plasma (such as free electrons) on the surface of the metal nanopattern layer 22 will resonate with the light of the target wavelength range emitted by the active layer 12. This resonance will selectively and strongly enhance the transmission of the light of the target wavelength range emitted by the active layer 12, while suppressing the transmission of light of non-resonant wavelength range by reflection and / or absorption, that is, filtering out the long and short clutter emitted by the active layer 12.

[0072] Therefore, the LED chip provided in this application embodiment includes an epitaxial stack 10 and a light selective transmission layer 20 located on one side of the light-emitting surface of the epitaxial stack 10; wherein, the epitaxial stack 10 includes a first type semiconductor layer 11, an active layer 12, and a second type semiconductor layer 13 stacked together; the light selective transmission layer 20 includes a transparent insulating layer 21 and a metal nanopattern layer 22 embedded in the transparent insulating layer 21, the metal nanopattern layer 22 constitutes a surface plasmon structure, and the resonant wavelength range of the surface plasmon structure matches the target wavelength range of the light emitted by the active layer, so that when the light of the target wavelength range emitted by the active layer 12 is emitted to the metal nanopattern layer 22, the plasma (such as free electrons) on the surface of the metal nanopattern layer 22 will... The light resonates with the light in the target wavelength range emitted by the active layer 12. This resonance selectively and strongly enhances the transmission of the light in the target wavelength range emitted by the active layer 12, while suppressing the transmission of light in the non-resonant wavelength range through reflection and / or absorption, that is, filtering out long and short noise waves emitted by the active layer 12. In this way, the light emission spectrum width of the LED chip can be effectively narrowed while maintaining the luminous efficiency of the LED chip, improving the color purity of the LED chip, and thus improving the display color gamut of the display screen. Furthermore, since the surface plasmon structure composed of the metal nanopattern layer 22 can selectively enhance the transmission of the light in the target wavelength range emitted by the active layer 12, the light extraction rate of the LED chip can also be improved, thereby improving the luminous efficiency of the LED chip.

[0073] Furthermore, by embedding the metal nanopattern layer 22 within the transparent insulating layer 21 to form a light selective transmission layer 20 located on one side of the light-emitting surface of the LED chip, the light selective transmission layer 20 can achieve highly selective filtering of light emitted from the active layer 12 within a relatively thin film thickness, thereby making the structure of the LED chip more compact. Moreover, the metal nanopattern layer 22 forms a surface plasmon structure to achieve highly selective filtering, which is insensitive to the incident light angle, and is therefore more suitable for divergent light sources such as LED chips.

[0074] Optionally, in some embodiments of this application, such as Figure 6 and Figure 7 As shown, the metal nanopattern layer 22 includes an array of metal nanoparticles 220. It can be understood that in the metal nanopattern layer 22, the metal nanoparticles 220 are periodically arrayed to form a periodic metal nanostructure, which in turn constitutes a surface plasmon resonance structure, capable of generating surface plasmon resonance for light in the target wavelength range emitted by the active layer 12.

[0075] The shape of the metal nanoparticles 220 is not limited in this embodiment. Optionally, the shape of the metal nanoparticles 220 can be any one or more of the following: nanopillars, nanocones, nanohemisphericals, cuboid nanostructures, polygonal nanostructures, and U-shaped nanostructures. Figure 6 and Figure 7 The example is a nanopillar-shaped metal nanoparticle 220.

[0076] It is understood that by adjusting the shape, size, spacing, and material of the metal nanoparticles 220, the transmittance wavelength range of the metal nanopattern layer 22 can be precisely controlled. Meanwhile, considering the particularly prominent issue of low color purity due to the wide emission spectrum of green LED chips, optionally, in some embodiments of this application, the light emitted by the active layer 12 in the target wavelength range is green light. The material of the metal nanoparticles 220 in the metal nanopattern layer 22 includes at least one of silver (Ag) and gold (Au), that is, the material of the metal nanoparticles 220 can be silver (Ag), gold (Au), or a combination of silver (Ag) and gold (Au). In other words, by selecting the material of the metal nanoparticles 220, the resonant wavelength range of the surface plasmon structure formed by the metal nanopattern layer 22 is adjusted, allowing the plasma (such as free electrons) on the surface of the metal nanopattern layer 22 to resonate with the green light emitted by the active layer 12, selectively enhancing the transmission of green light and suppressing clutter.

[0077] Alternatively, in some embodiments of this application, considering that the problem of low color purity caused by the wide emission spectrum of green LED chips is particularly prominent, therefore, referring to Figure 6 and Figure 7 As shown, when the light emitted by the active layer 12 in the target wavelength range is green light, the shape of the metal nanoparticles 220 can be set as nanopillars, and the diameter d1 of the metal nanoparticles 220 can be set to a range of 50nm-150nm, including the endpoint value; the spacing d2 between adjacent metal nanoparticles 220 can be set to a range of 100nm-300nm, including the endpoint value; that is, by setting the shape, size and spacing of the metal nanoparticles 220, the resonant wavelength range of the surface plasmon structure formed by the metal nanopattern layer 22 can be adjusted, so that the plasma (such as free electrons) on the surface of the metal nanopattern layer 22 can resonate with the green light emitted by the active layer 12, selectively enhancing the transmission of green light and suppressing clutter.

[0078] It is understood that the transmittable wavelength range of the metal nanopattern layer 22 is also the transmittable wavelength range of the light selective transmission layer 20. Optionally, in some embodiments of this application, the transmittable wavelength range of the light selective transmission layer 20 can be the target wavelength of the light emitted by the active layer 12 ± 20 nm, including the endpoint values. For example, if the target wavelength range of the light (green light) emitted by the active layer 12 is 520 nm-540 nm, then the transmittable wavelength range of the light selective transmission layer 20 can be 500 nm-560 nm.

[0079] Specifically, Figure 8 This illustration shows the reflectivity of the light selective transmission layer 20 in an LED chip according to an embodiment of this application for different wavelengths of light, such as... Figure 8 As shown, the light selective transmission layer 20 has a reflectivity of 0 for light with a wavelength range of 500nm-560nm, while having a reflectivity of 100% for light of other wavelengths. That is, the light selective transmission layer 20 can transmit light with a wavelength range of 500nm-560nm, while reflecting 100% of light of other wavelengths.

[0080] Figure 9 This paper shows a schematic diagram of the light emission spectrum of a green LED chip provided in an embodiment of this application, for comparison. Figure 1 As can be seen from the emission spectrum of the conventional green LED chip shown, the green LED chip provided in this embodiment has an emission spectrum width of 500nm-560nm and the color purity is improved from 85% to over 90%.

[0081] Optionally, in some embodiments of this application, such as Figure 2 As shown, the LED chip can have a vertical structure; specifically, in addition to the epitaxial stack 10 and the light selective transmission layer 20, the LED chip also includes:

[0082] First substrate 101; optionally, first substrate 101 may be silicon substrate;

[0083] The first bonding layer 102 is located on one side of the first substrate 101;

[0084] The epitaxial stack 10 is located on the side of the first bonding layer 102 away from the first substrate 101, that is, the first substrate 101 and the epitaxial stack 10 are connected by the first bonding layer 102. In the epitaxial stack 10, the first type semiconductor layer 11, the active layer 12 and the second type semiconductor layer 13 are stacked in the direction away from the first substrate 101.

[0085] A first electrode T1 is located on the side of the first substrate 101 opposite to the first bonding layer 102, and a second electrode T2 is located on the side of the second type semiconductor layer 13 opposite to the first substrate 101, so that the first electrode T1 is electrically connected to the first type semiconductor layer 11 through the first substrate 101 and the first bonding layer 102, and the second electrode T2 is electrically connected to the second type semiconductor layer 13.

[0086] The light selective transmission layer 20 is located on the side of the epitaxial stack 10 away from the first substrate 101, that is, at the top of the LED chip. Specifically, the light selective transmission layer 20 covers the sidewall of the epitaxial stack 10, the surface of the epitaxial stack 10 away from the first substrate 101, and the sidewall of the second electrode T2, and exposes at least part of the second electrode T2.

[0087] Understandably, for Figure 2 In the case of the vertical LED chip shown, the side of the epitaxial stack 10 away from the first substrate 101 (i.e., the top of the LED chip) is the light-emitting surface of the LED chip. Therefore, the light selective transmission layer 20 is disposed on the side of the epitaxial stack 10 away from the first substrate 101, thereby performing highly selective filtering on the light emitted from the light-emitting surface of the vertical LED chip, effectively narrowing the light emission spectrum width of the vertical LED chip, and improving the color purity of the vertical LED chip.

[0088] And, as Figure 2 As shown, the light selective transmission layer 20 not only covers the surface of the epitaxial stack 10 facing away from the first substrate 101, but also covers the sidewalls of the epitaxial stack 10. Thus, the light selective transmission layer 20 can selectively filter not only the light emitted from the top of the LED chip, but also the light emitted from the sidewalls of the epitaxial stack 10, thereby comprehensively improving the color purity of the LED chip. Furthermore, the light selective transmission layer 20 also covers the sidewalls of the second electrode T2. This ensures that the light selective transmission layer 20 completely covers the light-emitting surface of the vertically structured LED chip, and also serves as an insulating layer.

[0089] Optionally, a first reflective layer 103 may be disposed between the epitaxial stack 10 and the first bonding layer 102. The first reflective layer 103 can reflect light emitted from the epitaxial stack 10 toward the first substrate 101 toward the top of the LED chip, thereby improving the light extraction efficiency of the LED chip. In this case, the light selective transmission layer 20 can also cover the sidewalls of the first bonding layer 102 to fully cover the light extraction position of the vertically structured LED chip.

[0090] Alternatively, in some embodiments of this application, such as Figure 3 As shown, the LED chip can have a vertical structure with electrodes on the same side; specifically, in addition to the epitaxial stack 10 and the light selective transmission layer 20, the LED chip also includes:

[0091] Second substrate 201; optionally, the second substrate 201 can be a silicon substrate;

[0092] The second bonding layer 202 is located on one side of the second substrate 201;

[0093] The epitaxial stack 10 is located on the side of the second bonding layer 202 away from the second substrate 201, that is, the epitaxial stack 10 and the second substrate 201 are connected by the second bonding layer 202. In the epitaxial stack 10, the second type semiconductor layer 13, the active layer 12 and the first type semiconductor layer 11 are stacked in the direction toward the second substrate 201. The epitaxial stack 10 has a first groove U1 on the side facing the second substrate 201. The first groove U1 penetrates the first type semiconductor layer 11 and the active layer 12 and exposes a portion of the second type semiconductor layer 13.

[0094] A second reflective layer 203, an anti-diffusion layer 204, a first insulating layer 205, and a connecting metal layer 206 are disposed between the epitaxial stack 10 and the second bonding layer 202. The second reflective layer 203 is located on the side of the epitaxial stack 10 facing the second substrate 201. The anti-diffusion layer 204 covers the second reflective layer 203. The first insulating layer 205 covers the anti-diffusion layer 204, the surface of the epitaxial stack 10 facing the second substrate 201, and the sidewall of the first groove U1. The connecting metal layer 206 is located between the first insulating layer 205 and the second bonding layer 202, and the connecting metal layer 206 fills the first groove U1 and is electrically connected to the second type semiconductor layer 13.

[0095] The epitaxial stack 10 also has a second groove U2 on the side away from the second substrate 201. The second groove U2 penetrates the epitaxial stack 10 and exposes a portion of the anti-diffusion layer 204. A first electrode T1 is disposed on the anti-diffusion layer 204. A second electrode T2 is disposed on the side of the second substrate 201 away from the second bonding layer 202.

[0096] The light selective transmission layer 20 is located on the side of the epitaxial stack 10 away from the second substrate 201. The light selective transmission layer 20 covers the sidewall of the epitaxial stack 10, the surface of the epitaxial stack 10 away from the second substrate 201, and the sidewall of the first electrode T1, and exposes at least part of the first electrode T1.

[0097] It is understood that the first electrode T1 is electrically connected to the first type semiconductor layer 11 through the anti-diffusion layer 204 and the second reflective layer 203, and the second electrode T2 is electrically connected to the second type semiconductor layer 13 through the second substrate 201, the second bonding layer 202 and the connecting metal layer 206 filled in the first groove U1.

[0098] It is also understandable that, for Figure 3For the LED chip with the same electrode vertical structure shown, the side of the epitaxial stack 10 away from the second substrate 201 is the light-emitting surface of the LED chip. Therefore, the light selective transmission layer 20 is disposed on the side of the epitaxial stack 10 away from the second substrate 201, thereby performing highly selective filtering on the light emitted from the light-emitting surface of the LED chip with the same electrode vertical structure, effectively narrowing the light emission spectrum width of the LED chip with the same electrode vertical structure, and improving the color purity of the LED chip with the same electrode vertical structure.

[0099] And, as Figure 3 As shown, the light selective transmission layer 20 not only covers the surface of the epitaxial stack 10 facing away from the second substrate 201, but also covers the sidewalls of the epitaxial stack 10. Thus, the light selective transmission layer 20 can selectively filter light emitted from the surface of the epitaxial stack 10 facing away from the second substrate 201, and also selectively filter light emitted from the sidewalls of the epitaxial stack 10, thereby comprehensively improving the color purity of the LED chip. Furthermore, the light selective transmission layer 20 also covers the sidewalls of the first electrode T1. This ensures that the light selective transmission layer 20 completely covers the light-emitting surface of the LED chip with the vertical structure on the same side as the electrode, and also provides insulation between the first electrode T1 and the laterally positioned epitaxial stack 10.

[0100] Alternatively, in some embodiments of this application, such as Figure 4 As shown, the LED chip can be a standard structure; specifically, in addition to the epitaxial stack 10 and the light selective transmission layer 20, the LED chip also includes:

[0101] Third substrate 301;

[0102] The epitaxial stack 10 is located on one side of the third substrate 301. In the epitaxial stack 10, the second type semiconductor layer 13, the active layer 12 and the first type semiconductor layer 11 are stacked in a direction away from the third substrate 301. The epitaxial stack 10 has a third groove U3 on the side away from the third substrate 301. The third groove U3 penetrates the first type semiconductor layer 11 and the active layer 12 and exposes a portion of the second type semiconductor layer 13.

[0103] A first transparent conductive layer 302 is located on the side of the first type semiconductor layer 11 opposite to the third substrate 301, and the first transparent conductive layer 302 has a first through hole K1;

[0104] The first electrode T1 is located on the side of the first type semiconductor layer 11 away from the third substrate 301, and the first electrode T1 is electrically connected to the first type semiconductor layer 11 through the first through hole K1; the second electrode T2 is located on the second type semiconductor layer 13 exposed in the third groove U3, and is electrically connected to the second type semiconductor layer 13.

[0105] The light selective transmission layer 20 is located on the side of the first transparent conductive layer 302 away from the third substrate 301. The light selective transmission layer 20 covers the sidewall of the epitaxial stack 10, the surface of the first transparent conductive layer 302 away from the third substrate 301, and the sidewall of the first electrode T1 and the sidewall of the second electrode T2, and exposes at least a portion of the first electrode T1 and at least a portion of the second electrode T2.

[0106] It is understandable that the first transparent conductive layer 302 plays a role in lateral current expansion, thereby increasing the light-emitting area of ​​the LED chip in the upright structure, and thus improving the light-emitting efficiency of the LED chip in the upright structure.

[0107] It is also understandable that, for Figure 4 In the case of the LED chip with the upright structure shown, the side of the first transparent conductive layer 302 facing away from the third substrate 301 is the light-emitting surface of the LED chip. Therefore, the light selective transmission layer 20 is disposed on the side of the first transparent conductive layer 302 facing away from the third substrate 301, thereby performing highly selective filtering on the light emitted from the light-emitting surface of the LED chip with the upright structure, effectively narrowing the light emission spectrum width of the LED chip with the upright structure, and improving the color purity of the LED chip with the upright structure.

[0108] And, as Figure 4 As shown, the light selective transmission layer 20 not only covers the surface of the first transparent conductive layer 302 facing away from the third substrate 301, but also covers the sidewalls of the epitaxial stack 10. Thus, the light selective transmission layer 20 can selectively filter not only the light emitted from the surface of the first transparent conductive layer 302 facing away from the third substrate 301, but also the light emitted from the sidewalls of the epitaxial stack 10, thereby comprehensively improving the color purity of the LED chip in the upright structure. Furthermore, the light selective transmission layer 20 also covers the sidewalls of the first electrode T1 and the second electrode T2. This ensures that the light selective transmission layer 20 completely covers the light-emitting surface of the LED chip in the upright structure, and also serves as an insulating layer.

[0109] Alternatively, in some embodiments of this application, such as Figure 5 As shown, the LED chip can be a flip-chip structure; specifically, in addition to the epitaxial stack 10 and the light selective transmission layer 20, the LED chip also includes:

[0110] Fourth substrate 401;

[0111] The epitaxial stack 10 is located on one side of the fourth substrate 401. In the epitaxial stack 10, the second type semiconductor layer 13, the active layer 12 and the first type semiconductor layer 11 are stacked in a direction away from the fourth substrate 401. The epitaxial stack 10 has a fourth groove U4 on the side away from the fourth substrate 401. The fourth groove U4 penetrates the first type semiconductor layer 11 and the active layer 12 and exposes a portion of the second type semiconductor layer 13.

[0112] The second transparent conductive layer 402 is located on the side of the first type semiconductor layer 11 facing away from the fourth substrate 401;

[0113] The first electrode T1 is located on the side of the second transparent conductive layer 402 away from the fourth substrate 401, and the second electrode T2 is located on the second type semiconductor layer 13 exposed in the fourth groove U4;

[0114] The light selective transmission layer 20 is located on the side of the fourth substrate 401 away from the epitaxial stack 10, and the light selective transmission layer 20 covers the surface of the fourth substrate 401 away from the epitaxial stack 10.

[0115] Understandably, for Figure 5 In the case of the flip-chip LED chip shown, the side of the fourth substrate 401 facing away from the epitaxial stack 10 is its light-emitting surface. Therefore, the light selective transmission layer 20 is disposed on the side of the fourth substrate 401 facing away from the epitaxial stack 10, thereby performing highly selective filtering on the light emitted from the light-emitting surface of the flip-chip LED chip, effectively narrowing the light emission spectrum width of the flip-chip LED chip, and improving the color purity of the flip-chip LED chip.

[0116] like Figure 5 As shown, the flip-chip LED may further include an insulating reflective layer 403 covering the epitaxial stack 10 and the second transparent conductive layer 402. The insulating reflective layer 403 exposes at least a portion of the first electrode T1 and at least a portion of the second electrode T2. The insulating reflective layer 403 can reflect light emitted from the side of the epitaxial stack 10 away from the fourth substrate 401 toward the side toward the fourth substrate 401, thereby improving the light extraction efficiency of the flip-chip LED.

[0117] In practical applications, such as Figure 5 As shown, the flip-chip LED chip may also include a first pad P1 and a second pad P2. The first pad P1 penetrates the insulating reflective layer 403 and is electrically connected to the first electrode T1, and the second pad P2 penetrates the insulating reflective layer 403 and is electrically connected to the second electrode T2.

[0118] The various parts of this manual are described in a combination of parallel and progressive methods. Each part focuses on the differences between the other parts, and the same or similar parts can be referred to each other.

[0119] The features described above regarding the disclosed embodiments can be substituted or combined with each other to enable those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An LED chip, characterized in that, include: An epitaxial stack, wherein the epitaxial stack comprises a first type semiconductor layer, an active layer, and a second type semiconductor layer stacked together; A light selective transmission layer is located on the light-emitting surface side of the epitaxial stack. The light selective transmission layer includes a transparent insulating layer and a metal nanopattern layer embedded in the transparent insulating layer. The metal nanopattern layer constitutes a surface plasmon structure. The resonant wavelength range of the surface plasmon structure matches the target wavelength range of the light emitted by the active layer.

2. The LED chip according to claim 1, characterized in that, The metal nanopattern layer comprises an array of metal nanoparticles.

3. The LED chip according to claim 2, characterized in that, The shape of the metal nanoparticles is any one or more of the following: nanopillars, nanocones, nanohemisphers, cuboid nanostructures, polygonal nanostructures, and U-shaped nanostructures.

4. The LED chip according to claim 2, characterized in that, The light in the target wavelength range is green light, and the material of the metal nanoparticles includes at least one of silver and gold.

5. The LED chip according to claim 2, characterized in that, The light within the target wavelength range is green light; The metal nanoparticles are shaped like nanopillars, and the diameter of the metal nanoparticles ranges from 50 nm to 150 nm, including the endpoint values. The spacing between adjacent metal nanoparticles ranges from 100 nm to 300 nm, including the endpoint values.

6. The LED chip according to claim 1, characterized in that, The transmittable wavelength range of the light selective transmission layer is ±20nm of the target wavelength range of the light emitted by the active layer, including the endpoint values.

7. The LED chip according to any one of claims 1-6, characterized in that, The LED chip has a vertical structure; The LED chip also includes: First substrate; The first bonding layer located on one side of the first substrate; The epitaxial stack is located on the side of the first bonding layer away from the first substrate. In the epitaxial stack, the first type semiconductor layer, the active layer and the second type semiconductor layer are stacked in a direction away from the first substrate. A first reflective layer is also disposed between the epitaxial stack and the first bonding layer. A first electrode located on the side of the first substrate opposite to the first bonding layer, and a second electrode located on the side of the second type semiconductor layer opposite to the first substrate; The light selective transmission layer is located on the side of the epitaxial stack facing away from the first substrate. The light selective transmission layer covers the sidewall of the epitaxial stack, the surface of the epitaxial stack facing away from the first substrate, and the sidewall of the second electrode, and exposes at least a portion of the second electrode.

8. The LED chip according to any one of claims 1-6, characterized in that, The LED chip has a vertical structure with electrodes on the same side; The LED chip also includes: Second substrate; The second bonding layer is located on one side of the second substrate; The epitaxial stack is located on the side of the second bonding layer away from the second substrate. In the epitaxial stack, the second type semiconductor layer, the active layer, and the first type semiconductor layer are stacked in a direction toward the second substrate. The epitaxial stack has a first groove on the side toward the second substrate, and the first groove exposes a portion of the second type semiconductor layer. A second reflective layer, an anti-diffusion layer, a first insulating layer, and a connecting metal layer are disposed between the epitaxial stack and the second bonding layer. The second reflective layer is located on the side of the epitaxial stack facing the second substrate. The anti-diffusion layer covers the second reflective layer. The first insulating layer covers the anti-diffusion layer, the surface of the epitaxial stack facing the second substrate, and the sidewall of the first groove. The connecting metal layer is located between the first insulating layer and the second bonding layer, and the connecting metal layer fills the first groove and is electrically connected to the second type semiconductor layer. The epitaxial stack also has a second groove on the side away from the second substrate, the second groove exposes the anti-diffusion layer, a first electrode is disposed on the anti-diffusion layer, and a second electrode is disposed on the side of the second substrate away from the second bonding layer; The light selective transmission layer is located on the side of the epitaxial stack facing away from the second substrate. The light selective transmission layer covers the sidewall of the epitaxial stack, the surface of the epitaxial stack facing away from the second substrate, and the sidewall of the first electrode, and exposes at least a portion of the first electrode.

9. The LED chip according to any one of claims 1-6, characterized in that, The LED chip has a standard mounting structure; The LED chip also includes: Third substrate; The epitaxial stack is located on one side of the third substrate. In the epitaxial stack, the second type semiconductor layer, the active layer, and the first type semiconductor layer are stacked in a direction away from the third substrate. The epitaxial stack has a third groove on the side away from the third substrate, and the third groove exposes a portion of the second type semiconductor layer. A first transparent conductive layer is located on the side of the first type semiconductor layer opposite to the third substrate, and the first transparent conductive layer has a first through-hole; A first electrode and a second electrode, wherein the first electrode is located on the side of the first type semiconductor layer away from the third substrate and is electrically connected to the first type semiconductor layer through the first via; the second electrode is located on the second type semiconductor layer exposed in the third groove and is electrically connected to the second type semiconductor layer. The light selective transmission layer is located on the side of the first transparent conductive layer away from the third substrate. The light selective transmission layer covers the sidewalls of the epitaxial stack, the surface of the transparent conductive layer away from the third substrate, and the sidewalls of the first electrode and the second electrode, and exposes at least a portion of the first electrode and at least a portion of the second electrode.

10. The LED chip according to any one of claims 1-6, characterized in that, The LED chip has a flip-chip structure; The LED chip also includes: Fourth substrate; The epitaxial stack is located on one side of the fourth substrate. In the epitaxial stack, the second type semiconductor layer, the active layer, and the first type semiconductor layer are stacked in a direction away from the fourth substrate. The epitaxial stack has a fourth groove on the side away from the fourth substrate, and the fourth groove exposes a portion of the second type semiconductor layer. A second transparent conductive layer located on the side of the first type semiconductor layer facing away from the fourth substrate; A first electrode located on the side of the second transparent conductive layer opposite to the fourth substrate, and a second electrode located on the second type semiconductor layer exposed in the fourth groove; The light selective transmission layer is located on the side of the fourth substrate opposite to the epitaxial stack.

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