Light emitting diode and light emitting device

Abstract

The invention provides a light emitting diode and a light emitting device. The light emitting diode at least comprises a substrate; the semiconductor lamination layer is located on the substrate, the bonding layer is located between the semiconductor lamination layer and the substrate, the bonding layer is made of an insulating material, and the substrate and the semiconductor lamination layer are electrically isolated by the bonding layer; and the reflecting layer is located between the semiconductor lamination layer and the bonding layer, and the refractive index of the reflecting layer is smaller than that of the semiconductor lamination layer. According to the technical scheme, the back reflection system of the LED is improved, the reflection layer is inserted between the semiconductor lamination layer and the bonding layer, and the refractive index of the reflection layer is smaller than that of the semiconductor lamination layer, so that light emitted by the epitaxial structure is reflected at the interface of the reflection layer and then is emitted from the front side of the LED, the product brightness is improved, and the product quality is improved. The reflecting layer can also reduce light absorption of the substrate or heat generated by multiple reflections of light in the chip, and is beneficial to improving the performance and prolonging the service life of a high-power LED product.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a light emitting diode and a light emitting device. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor device whose basic structure includes a PN junction between a P-type semiconductor and an N-type semiconductor. When a forward voltage is applied to the LED, electrons and holes recombine at the junction of the PN junction to release energy, which is emitted in the form of photons to form light radiation.

[0003] In the prior art, a low-refractive-index material is usually deposited on the epitaxial structure as a bonding layer, such as SiO2. Since the refractive index of the epitaxial structure and SiO2 is quite different, there is a probability of total reflection at the interface between the two, which is conducive to the light being emitted from the front of the LED. However, part of the light generated by the light-emitting layer will still be confined to the inside of the chip and reflected or refracted back and forth, and eventually absorbed by the electrode structure or the light-emitting layer, or converted into heat consumption, or emitted from other angles. The external quantum efficiency is low, and the product brightness is not high. Therefore, it is necessary to provide an improved technical solution for the deficiencies in the above-mentioned prior art to improve the reflectivity and further improve the brightness of the LED product. Summary of the invention

[0004] In view of the above defects and deficiencies in the prior art, the purpose of the present application is to provide a light emitting diode and a light emitting device to solve one or more of the above problems.

[0005] According to one aspect of the present application, a light emitting diode is provided, comprising at least:

[0006] substrate;

[0007] A semiconductor stack, located on the substrate, comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence;

[0008] A bonding layer, located between the substrate and the semiconductor stack, the bonding layer is an insulating material, and the substrate and the semiconductor stack are electrically isolated by the bonding layer;

[0009] The reflective layer is located between the semiconductor stack and the bonding layer, and the refractive index of the reflective layer is smaller than the refractive index of the semiconductor stack.

[0010] According to another aspect of the present application, a light emitting device is provided, the light emitting device comprising:

[0011] Package substrate;

[0012] At least one light emitting diode is arranged on the surface of the packaging substrate, and the packaging substrate is electrically connected to the electrode structure of the light emitting diode; the light emitting diode is the light emitting diode described in the above technical solution.

[0013] Compared with the prior art, the light emitting diode and the light emitting device provided by the present application have at least the following beneficial effects:

[0014] The technical solution of the present application improves the back reflection system of the LED by inserting a reflection layer between the semiconductor stack and the bonding layer. The refractive index of the reflection layer is smaller than the refractive index of the semiconductor stack and the bonding layer, such as a single-layer structure with a low refractive index, a stacked structure with alternating different refractive indices, or a DBR structure, thereby enhancing the reflection effect. In addition, the insulating bonding layer electrically isolates the semiconductor stack and the substrate to achieve thermal and electrical separation, thereby improving the reliability of the device. At the same time, the bonding layer can cooperate with the reflection layer to further improve the reflection capability. In addition, the light-emitting device provided by the present application includes the light-emitting diode provided by the above technical solution. Therefore, the light-emitting device also has the above-mentioned good technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The positional relationships described in the drawings in the following description are based on the directions in which the components are drawn in the diagrams, unless otherwise specified.

[0016] For the purpose of convenience or clarity, the thickness and size of each layer shown in the drawings can be exaggerated, omitted or roughly drawn. In addition, the size of the light emitting diode does not completely reflect the actual size.

[0017] Figure 1 Shown is a schematic cross-sectional structure diagram of a light emitting diode in the prior art;

[0018] Figure 2 Shown is a schematic cross-sectional structure diagram of a light emitting diode provided in Example 1 of the present application;

[0019] Figure 3 Shown is a schematic cross-sectional structure diagram of a light emitting diode provided in Example 2 of the present application;

[0020] Figure 4 Shown is a schematic cross-sectional structure diagram of a light emitting diode provided in Example 3 of the present application;

[0021] Figure 5Shown is a partial enlarged schematic diagram of a light emitting diode provided in Example 3;

[0022] Figure 6 Shown is a schematic cross-sectional structure diagram of a light-emitting device provided in Embodiment 4 of the present application.

[0023] List of reference numerals:

[0024] 100 Substrate

[0025] 200 Bonding layer

[0026] 300 Reflection Layer

[0027] 311 First film layer

[0028] 312 Second film layer

[0029] 313 Third film layer

[0030] 320 DBR structure

[0031] 321 First Material Layer

[0032] 322 Second material layer

[0033] 330 Third Material Layer

[0034] 400 Semiconductor stack

[0035] 410 first semiconductor layer

[0036] 420 Active layer

[0037] 430 Second semiconductor layer

[0038] 500 Insulation

[0039] 610 First Electrode

[0040] 620 Second Electrode

[0041] 10 Lighting device

[0042] 101 Package substrate

[0043] 102 Light-emitting element

[0044] 103 First packaging electrode

[0045] 104 Second packaging electrode

[0046] 105 Die Bonding Area

[0047] 106 Electrode lead DETAILED DESCRIPTION

[0048] Figure 1This is a structural diagram of a light-emitting diode in the prior art. A material with a relatively small refractive index, such as SiO2 material, is deposited on the epitaxial layer as a bonding layer. The bonding layer also serves as a reflective layer to reflect the light emitted by the active layer. The light emitted by the active layer is reflected by the bonding layer and finally emitted from the front of the LED. In order to further improve the reflectivity of the LED back reflection system, promote light emission, and improve product brightness, the present application provides a light-emitting diode, which at least includes:

[0049] A substrate; a semiconductor stack located on the substrate, comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; a bonding layer located between the substrate and the semiconductor stack, the bonding layer being an insulating material, the substrate and the semiconductor stack being electrically isolated by the bonding layer; a reflective layer located between the semiconductor stack and the bonding layer, the refractive index of the reflective layer being less than the refractive index of the semiconductor stack.

[0050] By improving the back reflection system of the LED, a reflection layer is inserted between the semiconductor stack and the bonding layer. The refractive index of the reflection layer is smaller than that of the semiconductor stack and the bonding layer, such as a single-layer structure with a low refractive index, a stacked structure with alternating refractive indices, or a DBR structure, thereby enhancing the reflection effect. In addition, the insulating bonding layer electrically isolates the semiconductor stack and the substrate to achieve thermal and electrical separation and improve device reliability. At the same time, the bonding layer can cooperate with the reflection layer to further improve the reflection capability.

[0051] In some embodiments, the reflective layer is a stacked structure, and the material may be SiO2, TiO2, NbO2, Al2O3, MgF2 or SiN x Two or more of the following.

[0052] In some embodiments, the reflective layer includes a first film layer and a second film layer stacked in sequence from the semiconductor stack to the bonding layer, the refractive index of the first film layer is less than the refractive index of the second film layer, and the refractive indexes of the two film layers are both less than the refractive index of the semiconductor stack. By taking advantage of the different refractive indices between different film layers and the easy reflection at the film layer interface, the reflectivity of the back side of the LED is increased, and the light brightness of the product is improved.

[0053] In some embodiments, the thickness of the first film layer is between The thickness of the second film layer is between The first film layer is in contact with the epitaxial structure and can provide certain protection and lattice transition effects.

[0054] In some embodiments, the material of the bonding layer includes SiO2, and the refractive index of the first film layer is less than or equal to the refractive index of the bonding layer. The bonding layer and the second film layer are made of the same material and have the same or similar refractive index, forming a composite refractive index variable stacked structure, thereby improving the reflectivity at each interface and thereby improving the overall light output.

[0055] In some embodiments, the thickness of the bonding layer is between This thickness ensures the bonding strength.

[0056] In some embodiments, the reflective layer includes a DBR structure, wherein the DBR structure has 1 to 8 layer pairs consisting of a first material layer and a second material layer, wherein the refractive index of the first material layer is different from the refractive index of the second material layer, and both are smaller than the refractive index of the semiconductor stack. By inserting the DBR structure instead of a single layer of material with a low refractive index, the back reflectivity is increased, thereby improving the brightness.

[0057] In some embodiments, the first material layer includes SiO2, and the second material layer includes one or more of TiO2, NbO2, ZrO2 or Ta2O5.

[0058] In some embodiments, the reflective layer further includes a third material layer, the third material layer is located between the DBR structure and the semiconductor stack, and the refractive index of the third material layer is less than that of the second material layer. A third material layer is inserted between the DBR structure and the semiconductor stack, and the refractive index of the third material layer is less than or equal to that of the first material layer, so as to further improve the reflectivity of the reflective layer to light.

[0059] In some embodiments, the third material layer and the first material layer have the same or different material composition. For example, both are SiO2. While forming a reflective structure with alternating high and low refractive indices, the third material layer can also protect the semiconductor stack. The third material layer can also be MgF2 material, which has a relatively lower refractive index and has a better total reflection effect when combined with epitaxy, further increasing the reflectivity.

[0060] In some embodiments, the thickness of the third material layer is greater than that of the first material layer; the thickness of the third material layer is greater than that of the second material layer. The third material layer in contact with the semiconductor stack plays a relatively large role in the reflection of light, and the relationship between its thickness and wavelength is regulated to achieve a better reflectivity, and to provide sufficient mechanical strength and chemical stability, thereby improving the reliability and life of the LED.

[0061] In some embodiments, the semiconductor stack has a first surface and a second surface opposite to each other, the second surface is close to the substrate, and the second surface is a roughened surface. The roughened surface can improve the light extraction efficiency of the LED and enhance the luminous brightness.

[0062] In some embodiments, the substrate material includes one or more of sapphire, Al2O3, AlN, SiC or SiN, and a substrate with high heat dissipation capability is mainly selected for heat dissipation.

[0063] In some embodiments, the surface of the first semiconductor layer in the semiconductor stack away from the substrate is a first mesa on which a first electrode is disposed, and the surface of the second semiconductor layer exposed from the semiconductor stack is a second mesa on which a second electrode is disposed.

[0064] In some embodiments, the wavelength of the light radiated by the light emitting diode is between 625nm and 740nm. The above technical solution is particularly suitable for the design of the reflective layer structure of red light LED products.

[0065] The present application also provides a light-emitting device, the light-emitting device comprising:

[0066] Package substrate;

[0067] At least one light emitting diode is arranged on the surface of the packaging substrate, and the packaging substrate is electrically connected to the electrode structure of the light emitting diode; the light emitting diode is the light emitting diode described in any one of the above technical solutions. The light emitting device includes the above light emitting diode, so it also has good light emitting brightness.

[0068] The composition and dopant of each layer included in the light-emitting diode of the present application can be analyzed by any suitable method, such as secondary ion mass spectrometer (SIMS). The thickness of each layer included in the light-emitting diode of the present application can be analyzed by any suitable method, such as transmission electron microscopy (TEM) or scanning electron microscopy (SEM), in combination with different element contents and element distributions on the EDS spectrum, for example.

[0069] The following specific embodiments illustrate the implementation of the present application, and those familiar with the technology can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0070] For ease of description, the direction from the bonding layer to the semiconductor stack is defined as upward, and the opposite direction is defined as downward. The semiconductor stack away from the substrate is the first semiconductor layer, the semiconductor stack close to the substrate is the second semiconductor layer, and the active layer is in between.

[0071] Embodiment 1:

[0072] like Figure 2 As shown, this embodiment provides a light emitting diode, which includes at least a substrate 100, a bonding layer 200, a reflective layer 300 and a semiconductor stack 400 from bottom to top, specifically:

[0073] The substrate 100 includes one or more of sapphire, Al2O3, AlN, SiC or SiN. These substrates are all substrates with strong heat dissipation, which can effectively help the light-emitting diode to dissipate heat, help optimize the thermal management of the LED device, extend the life of the LED and improve its stability. In this embodiment, sapphire is selected as the substrate material. Furthermore, the thickness of the substrate 100 is between 50 μm and 300 μm.

[0074] The bonding layer 200 is located between the substrate 100 and the semiconductor stack 400, and is used to enhance the bonding force between the semiconductor stack 400 and the substrate 100, and prevent the occurrence of delamination, shedding and other problems during subsequent processes or use. The bonding layer 200 is an insulating material, which electrically isolates the substrate 100 from the semiconductor stack 400; such a design can divide the light-emitting diode into two parts, the upper and lower parts. The semiconductor stack 400 above the bonding layer 200 converts electrical energy into light to generate brightness, and the substrate 100 below the bonding layer 200 is easy to dissipate heat because there is no current passing through it. The design of thermal and electrical separation can effectively improve the reliability of the product. Optionally, the material of the bonding layer 200 is SiO2, and the refractive index of SiO2 is about 1.45, while the refractive index of the semiconductor stack 400 is about 3.4, which allows the light to be well reflected back to the inside of the chip when it reaches the interface of the bonding layer 200, that is, the bonding layer 200 also plays a certain reflective role, which is conducive to the front light of the chip. At the same time, the thermal expansion coefficient of SiO2 is relatively close to that of other material layers of the chip, which helps to reduce the impact of thermal stress on device performance, assists in heat dissipation, and reduces the operating temperature of the device.

[0075] In the above embodiment, the thickness of the bonding layer 200 is between In between, the bonding layer 200 is flattened by chemical mechanical polishing, and the flat bonding layer 200 is activated by chemical solution and then bonded to the flat substrate 100 by high temperature and high pressure. By optimizing the preparation process of the SiO2 bonding layer, the interface quality can be further improved and the interface defect density can be reduced. The high-density SiO2 material can also isolate the moisture and other impurities between the device and the environment, play a role in protecting the device, and improve the service life and stability of the device.

[0076] The reflective layer 300 is located between the semiconductor stack 400 and the bonding layer 200. The refractive index of the reflective layer 300 is less than that of the semiconductor stack 400, so that the light emitted by the active layer 420 is reflected multiple times at the interface between the semiconductor stack 400 and the reflective layer 300 and the interface between the reflective layer 300 and the bonding layer 200 and is finally captured by the high refractive index layer, i.e., the semiconductor stack 400. On the basis of the bonding layer 200 having a certain reflective effect, the design of the reflective layer 300 can make the total reflection more and the interface reflectivity higher, thereby improving the external quantum efficiency and the brightness of the product. Furthermore, the material of the reflective layer 300 can be SiO2, TiO2, NbO2, Al2O3, MgF2 or SiN x One or more of the above. In this embodiment, the reflective layer 300 is made of MgF2 material, which has a relatively lower refractive index and higher reflectivity than the SiO2 bonding layer, as well as good chemical stability and high-temperature aging performance. According to the test, the brightness of the product using MgF2 material as the reflective layer is about 5% to 10% higher than that of the product without the reflective layer, and the brightness of the product is significantly improved. The reflective layer 300 is a continuous structural layer, which can achieve a comprehensive and uniform reflection effect on the light from the active layer.

[0077] The semiconductor stack 400 is located on the reflective layer 300, and includes a first semiconductor layer 410, an active layer 420 and a second semiconductor layer 430 stacked in sequence from top to bottom. As an example, the first semiconductor layer 410 is composed of a III-V group or II-VI group compound semiconductor, doped with N-type dopants such as Si, Ge, Sn, Se or Te, and is an N-type semiconductor layer for providing electrons for composite luminescence; the second semiconductor layer 430 is composed of a III-V group or II-VI group compound semiconductor, doped with P-type dopants such as Mg, Zn, Ca, Sr or Ba, and is a P-type semiconductor layer for providing holes for composite luminescence. The active layer 420 may have, but is not limited to, any one of a single well structure, a multi-well structure, a single quantum well structure or a multi-quantum well structure, and is used for composite luminescence of electrons and holes. The material of the active layer 420 in this embodiment adopts an aluminum indium gallium phosphide (AlGaInP) system, and the light emitted is red light, and the wavelength of the radiated light is between 625nm and 740nm.

[0078] In the above embodiment, the semiconductor stack 400 has a first surface and a second surface opposite to each other, the second surface is a surface close to the substrate 100, that is, a surface in contact with the reflective layer 300, and the second surface is a roughened surface. A certain degree of roughened surface can improve the light extraction efficiency of the LED and enhance the luminous brightness. Further, the roughness of the roughened surface ranges from 100 to 500 nm.

[0079] In some embodiments, the surface of the first semiconductor layer 410 in the semiconductor stack 400 away from the substrate 100 is a first table, on which the first electrode 610 is disposed, and the exposed surface of the second semiconductor layer 430 is a second table, on which the second electrode 620 is disposed. The light emitting diode further includes an insulating layer 500, the insulating layer 500 is located above and on the sidewall of the semiconductor stack 400, and the insulating layer 500 has through holes that penetrate the light emitting table of the first semiconductor layer 410 and the second table of the second semiconductor layer 430 respectively; the electrode structure includes a first electrode 610 and a second electrode 620, the electrode material includes, for example, gold (Au), germanium (Ge), beryllium (Be), nickel (Ni), palladium (Pd), zinc (Zn) or an alloy thereof, the first electrode 610 and the second electrode 620 are respectively located on the insulating layer 500 and fill the above-mentioned through holes respectively, the first electrode 610 forms an electrical contact with the first semiconductor layer 410, and the second electrode 620 forms an electrical contact with the second semiconductor layer 430.

[0080] In order to improve the emission efficiency of the light radiated by the active layer 420 from the front and side walls of the LED chip, the front and side walls of the semiconductor stack 400 are roughened respectively. The roughness range of the front and side walls of the first semiconductor layer 410 is 100nm to 500nm.

[0081] The wavelength of the radiated light of the light emitting diode provided in this embodiment is between 625nm and 740nm, which is suitable for red light LED products, especially for high-power LED products, and has a more obvious effect on improving the problem of poor heat dissipation of high-power devices. The electrodes of the LED chip are connected to the external power supply through electrode leads, and the electrical path and the thermal path are separated and designed, so that there is no direct electrical connection between the electrodes and the substrate of the LED chip. The light is reflected back into the semiconductor stack at the interface of the reflective layer and emitted from the front of the chip, which reduces the absorption of light in the bonding layer and the substrate and the heat conversion, improves the heat dissipation performance and reliability of the LED, optimizes the electrical performance of the device, and thus improves the luminous efficiency and stability of the LED.

[0082] Embodiment 2:

[0083] like Figure 3 As shown, this embodiment provides a light emitting diode, which includes at least: a substrate 100, a bonding layer 200, a reflective layer 300 and a semiconductor stack 400 from bottom to top.

[0084] The other similarities between the light emitting diode and the first embodiment are not described here, and the difference is that:

[0085] The reflective layer is a laminated structure, and its material can be SiO2, TiO2, NbO2, Al2O3, MgF2 or SiN x In some embodiments, the reflective layer 300 includes a first film layer 311 and a second film layer 312 stacked in sequence, the refractive index of the first film layer 311 is less than the refractive index of the second film layer 312, and the refractive indexes of the two film layers are both less than the refractive index of the semiconductor stack. Optionally, the refractive index of the second film layer is higher than the refractive index of the bonding layer, and a low-high-low refractive index variation stacked structure is formed from the reflective layer 300 to the bonding layer 200. The different refractive indices between different film layers and the easy reflection at the film layer interface are used to increase the reflectivity of the back of the LED and improve the light brightness of the product. Further, the reflective layer 300 also includes a third film layer 313, and the third film layer 313 is in contact with the bonding layer 200, that is, the reflective layer 300 is designed as a stacked structure of the first film layer 311 / the second film layer 312 / the third film layer 313, and the refractive index of the second film layer 312 is higher than the refractive index of the first film layer 311 and the third film layer 313 adjacent to it.

[0086] In some embodiments, the material of the bonding layer 200 includes SiO2, and the refractive index of the first film layer is less than or equal to the refractive index of the bonding layer 200. Furthermore, the bonding layer 200 and the first film layer 311 are made of the same material and have the same or similar refractive index, for example, the material can also be SiO2. A low-high-low refractive index variation stacked structure is formed from the first film layer 311 to the bonding layer 200, and the second film layer 312 can be made of any material with a refractive index higher than that of the first film layer 311 or the bonding layer 200 and lower than that of the semiconductor stack 400, for example, the second film layer 312 is made of SiN x The first film layer 311 and the third film layer 313 are both made of SiO2. In this case, the third film layer 313 and the bonding layer 200 are made of the same material. x The difference in refractive index between SiO2 and SiO2 helps to achieve stronger light reflection at the film interface. x ) enters the low refractive index medium (SiO2), significant light reflection will occur, improving the light output from the front of the chip. Furthermore, the bonding layer 200 can also serve as the last film layer 313 of the reflective layer 300, and together with the first film layer 311 and the second film layer 312, form a three-layer stacked structure with different refractive indices, thereby improving the reflectivity at each interface and thus improving the overall light output. As an example, the stacked layers of the reflective layer 300 are SiO2 / SiN x / SiO2, the last layer of SiO2 can be set separately from the SiO2 bonding layer, or the bonding layer formed by the SiO2 material can replace the last film layer of the reflective layer 300, SiN x The refractive index of the second film layer 312 of the material is between 1.8 and 2.2, which is greater than the refractive index of SiO2. By utilizing the difference in refractive indices of different film layers and adjusting parameters such as thickness, the back reflectivity of the LED can be effectively increased.

[0087] In some embodiments, the thickness of the first film layer 311 is between The thickness of the second film layer 312 is between The thickness of the third film layer 313 is between The first film layer 311 is in contact with the epitaxial structure and is relatively thick, providing a certain degree of protection and lattice transition. The second film layer 312 is a high refractive index film layer, which plays a key role in the laminated structure. It makes the light reflected from this layer more closely matched with the light reflected from other layers (such as the third film layer 313 or the bonding layer 200) in phase, thereby enhancing the overall reflection effect. As an example, the reflective layer 300 is made of SiO2 / SiN x / SiO2 stacked material, and the thickness of the three film layers are

[0088] In the above embodiment, the thickness of the bonding layer 200 is between The bonding layer 200 is planarized by chemical mechanical polishing, and the flat bonding layer 200 is activated by a chemical solution and then bonded to the flat substrate 100 by high temperature and high pressure.

[0089] According to the test, the use of SiO2 / SiN x The brightness of the product using the / SiO2 laminated material as the reflective layer is about 2% to 5% higher than that of the product using a single-layer SiO2 reflective layer, and the brightness of the product is also improved.

[0090] Embodiment three:

[0091] The other similarities between the light emitting diode and the first and second embodiments are not described here in detail, and the difference lies in that:

[0092] The reflective layer 300 includes a DBR structure 320. The DBR structure 320 has 1 to 8 layer pairs consisting of a first material layer 321 and a second material layer 322. The refractive index of the first material layer 321 is different from that of the second material layer 322, and both are smaller than the refractive index of the semiconductor stack 400. The light reflectivity is improved by using the principle of total interface reflection of materials with different refractive indices. The back reflectivity of the LED is improved by inserting a DBR structure 320 with a higher reflectivity and an adjustable reflection wavelength range to replace a single layer of material with a low refractive index (such as a SiO2 layer or a MgF2 layer), thereby increasing the brightness. The reflectivity can be further improved by increasing the number of material layers of the DBR structure 320. Each additional pair of high and low refractive index layer pairs will increase the reflectivity at a specific wavelength. Further, the DBR structure includes 3 to 6 layer pairs consisting of a first material layer 321 and a second material layer 322, so as to take into account issues such as process cost and chip size. Further, the single layer thickness of the first material layer 321 is between The single layer thickness of the second material layer 322 is between The overall thickness of the DBR structure 320 is controlled between In order to balance the production cost and luminous brightness.

[0093] In some embodiments, the first material layer 321 includes SiO2, and the second material layer 322 includes one or more of TiO2, NbO2, ZrO2 or Ta2O5. As an example, the second material layer 322 uses TiO2 material to form a DBR structure stacked by SiO2 / TiO2. As an example, the second material layer 322 uses NbO2 material to form a DBR structure stacked by SiO2 / NbO2. Since the refractive index of TiO2 is generally higher than that of NbO2, under the same thickness and optical conditions, the reflection effect of the TiO2 layer on light will be stronger, and the DBR structure 320 stacked by SiO2 / TiO2 has a better reflection effect on light. In an optional embodiment, the starting layer of the DBR structure 320 from top to bottom is the first material layer 321, that is, the first layer directly in contact with the semiconductor stack 400 is the first material layer 321, and SiO2 can play a good protective role on the semiconductor stack 400, and also help to continue to form each subsequent DBR material layer. The termination layer of the DBR structure 320 from top to bottom is the second material layer 322 , that is, the DBR structure 320 includes a plurality of complete material layer pairs, and finally the TiO 2 layer is in direct contact with the bonding layer 200 .

[0094] In some embodiments, the reflective layer 300 further includes a third material layer 330, which is located between the DBR structure 320 and the semiconductor stack 400, and has a refractive index lower than that of the second material layer 322. The third material layer 330 is inserted between the DBR structure 320 and the semiconductor stack 400, and the third material layer 330 and the DBR structure 320 further improve the reflectivity of the reflective layer to light.

[0095] In some embodiments, the third material layer 330 and the first material layer 321 have the same material composition. For example, both are SiO2. While forming a high-low staggered reflective structure, the third material layer 330 made of SiO2 can also provide certain protection for the semiconductor stack 400 and the reflective layer 300. Furthermore, the thickness of the third material layer 330 is Thickness not less than This provides good protection for the structure of the light-emitting part above.

[0096] In some embodiments, the third material layer 330 is a material with a lower refractive index than the first material layer 321, such as MgF2 and SiO2. The third material layer 330 with a lower refractive index has a greater difference in refractive index with the semiconductor stack 400, resulting in more total reflection and improved interface reflectivity, thereby improving external quantum efficiency and product light brightness. The thickness of the low refractive index third material layer 330 is Thickness not less than The light-emitting diode provided in this embodiment is a horizontal structure product, that is, the electrodes are all arranged on one side, the insulating bonding layer 200 separates the electrical path and the thermal path, the light generated by the semiconductor stack 400 and incident on the substrate 100 is reflected by the reflective layer 300, and there is no direct electrical connection between the electrodes of the LED chip and the substrate 100. The substrate with good heat dissipation can effectively dissipate heat and improve the reliability of the device. The reflective layer formed by SiO2 and DBR structure can be a continuous structure layer, which further improves the reflection effect of light. The reflective layer structure provided in this embodiment is suitable for high-power LED products, which effectively improves the problem of poor heat dissipation of high-power devices.

[0097] In some embodiments, the thickness of the third material layer 330 is greater than that of the first material layer 321; the thickness of the third material layer 330 is greater than that of the second material layer 322. The third material layer 330 in contact with the semiconductor stack 400 plays a relatively large role in the reflection of light. The relationship between its thickness and wavelength can be adjusted to achieve a better reflectivity and provide sufficient mechanical strength and chemical stability, thereby improving the reliability and life of the LED. Further, the thickness of the third material layer 330 is between between.

[0098] According to the test, the brightness of the product using the third material layer 330 and the DBR structure 320 as the reflective layer is about 2% to 5% higher than that of the product using the single-layer SiO2 reflective layer, and the brightness of the product is also improved.

[0099] Embodiment 4:

[0100] like Figure 6 As shown, this embodiment provides a light-emitting device 10, which includes a circuit substrate 101 and a light-emitting element 102 arranged above the circuit substrate 101. The light-emitting element 102 can be an LED chip provided in Example 1 and / or Example 2 and Example 3 of the present application, and the LED chip is electrically connected to the circuit substrate 101 through electrodes. Specifically, a solid crystal area 105, a first packaging electrode 103 and a second packaging electrode 104 are provided on the circuit substrate 101, and the light-emitting element 102 is arranged on the circuit substrate 101 through the solid crystal area 105, and the electrodes of the light-emitting element 102 are respectively connected to the first packaging electrode 103 and the second packaging electrode 104 through electrode leads 106. Since the light-emitting diodes provided in Examples 1 to 3 have improved back reflection systems, and the reflectivity and light brightness of the light are improved by inserting a reflective layer 300, the light-emitting device 10 also has excellent light brightness.

[0101] In summary, the light emitting diode and the light emitting device provided by the present application effectively overcome various shortcomings in the prior art and have high industrial utilization value.

[0102] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A light emitting diode, characterized in that: At least: substrate; A semiconductor stack, located on the substrate, comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; A bonding layer, located between the substrate and the semiconductor stack, the bonding layer is an insulating material, and the substrate and the semiconductor stack are electrically isolated by the bonding layer; The reflective layer is located between the semiconductor stack and the bonding layer, and the refractive index of the reflective layer is smaller than the refractive index of the semiconductor stack.

2. The light emitting diode according to claim 1, characterized in that: The reflective layer is a laminated structure, and its material is SiO2, TiO2, NbO2, Al2O3, MgF2 or SiN x Two or more of the following.

3. The light emitting diode according to claim 1, characterized in that: In the direction from the semiconductor stack to the bonding layer, the reflective layer includes a first film layer and a second film layer stacked in sequence, the refractive index of the first film layer is smaller than the refractive index of the second film layer, and the refractive indices of the two film layers are both smaller than the refractive index of the semiconductor stack.

4. The light emitting diode according to claim 3, characterized in that: The thickness of the first film layer is between The thickness of the second film layer is between between.

5. The light emitting diode according to claim 1, characterized in that: The reflective layer comprises a DBR structure having 1 to 8 layer pairs consisting of a first material layer and a second material layer. The refractive index of the first material layer is different from the refractive index of the second material layer and is smaller than the refractive index of the semiconductor stack.

6. The light emitting diode according to claim 5, characterized in that: The first material layer includes SiO2, and the second material layer includes one or more of TiO2, NbO2, ZrO2 or Ta2O5.

7. The light emitting diode according to claim 6, characterized in that: The reflective layer further includes a third material layer, which is located between the DBR structure and the semiconductor stack. The refractive index of the third material layer is smaller than that of the second material layer, and the refractive index of the third material layer is smaller than or equal to that of the first material layer.

8. The light emitting diode according to claim 7, characterized in that: The third material layer has the same or different material composition as the first material layer.

9. The light emitting diode according to claim 1, characterized in that: The substrate includes one or more of sapphire, Al2O3, AlN, SiC or SiN.

10. The light emitting diode according to claim 1, characterized in that: The surface of the first semiconductor layer in the semiconductor stack away from the substrate is a first mesa, on which a first electrode is arranged; the surface of the second semiconductor layer exposed from the semiconductor stack is a second mesa, on which a second electrode is arranged.

11. A light emitting device, characterized in that: The light emitting device comprises: Package substrate; At least one light emitting diode is disposed on the surface of the packaging substrate, and the packaging substrate is electrically connected to the electrode structure of the light emitting diode; the light emitting diode is the light emitting diode according to any one of claims 1 to 10.

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