Light-emitting device capable of improving fracture, preparation method thereof and display panel

Abstract

The invention provides a light-emitting device for improving fracture, a preparation method thereof and a display panel, and belongs to the technical field of photoelectron manufacturing. The light-emitting device comprises at least two light-emitting units, bridging metal and a first bearing layer, the at least two light-emitting units are arranged on the surface of the first bearing layer at intervals, and the bridging metal is located on the surface of the first bearing layer and located in a gap between the at least two light-emitting units. The at least two light-emitting units are connected in series through the bridging metal. The problem that the bridging metal is easy to break can be improved, and the reliability of the light-emitting device is improved.

Description

Technical Field

[0001] This disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a light-emitting device with improved fracture resistance, a method for fabricating the same, and a display panel. Background Technology

[0002] A high-voltage light-emitting diode (LED) is a light-emitting diode with a higher operating voltage than a traditional LED. The operating voltage of a high-voltage LED can reach tens of volts or even higher. High-voltage LEDs achieve their high-voltage operating characteristics by integrating multiple light-emitting units in series within the chip.

[0003] In related technologies, when fabricating high-voltage LED chips, an epitaxial layer is typically grown on a substrate, and multiple independent light-emitting units are formed by etching isolation trenches on the epitaxial layer. Then, adjacent light-emitting units are connected in series by bridging metal.

[0004] In micro-display applications, Micro LEDs with dimensions smaller than 50 μm are used. Micro LEDs typically require the removal of the growth substrate to achieve better optical performance and integration. However, after substrate removal, the mechanical strength of the remaining epitaxial layer is significantly reduced. The bridging metal structure at the micrometer scale is inherently fragile and cannot withstand the mechanical stress of subsequent processes and use, making the bridging metal prone to breakage and making it difficult to maintain the connection reliability of high-voltage LEDs. Summary of the Invention

[0005] This disclosure provides an improved light-emitting device with reduced breakage, a method for fabricating the same, and a display panel, which can improve the problem of easily broken bridging metals and enhance the reliability of the light-emitting device. The technical solution is as follows:

[0006] This disclosure provides a light-emitting device comprising: at least two light-emitting units, a bridging metal, and a first carrier layer. The at least two light-emitting units are arranged at intervals on the surface of the first carrier layer. The bridging metal is located on the surface of the first carrier layer and in the gap between the at least two light-emitting units. The at least two light-emitting units are connected in series through the bridging metal.

[0007] In another implementation of the present disclosure, the light-emitting device further includes a second carrier layer, which is located on the surface of the first carrier layer away from the at least two light-emitting units, and the second carrier layer surrounds the sidewall of the first carrier layer.

[0008] In another implementation of the embodiments of this disclosure, the first support layer includes an inorganic material layer, and the second support layer includes an organic material layer.

[0009] In another implementation of the present disclosure, the first carrier layer includes at least one of a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, and a titanium oxide layer.

[0010] In another implementation of the present disclosure, the second carrier layer includes a photosensitive material layer.

[0011] In another implementation of the present disclosure, the thickness of the first carrier layer is 1 μm to 5 μm.

[0012] In another implementation of the embodiments of this disclosure, the thickness of the bridging metal is 0.3 μm to 2 μm.

[0013] This disclosure provides a method for fabricating a light-emitting device, the method comprising: forming at least two light-emitting units arranged at intervals on a first carrier layer; forming a bridging metal on the surface of the first carrier layer, the bridging metal being located in the gap between the at least two light-emitting units, and the at least two light-emitting units being connected in series through the bridging metal.

[0014] In another implementation of the present disclosure, forming at least two light-emitting units spaced apart on a first carrier layer includes: forming at least two light-emitting units on a first substrate; forming a photosensitive adhesive layer on the first substrate covering the at least two light-emitting units; bonding the photosensitive adhesive layer to a second substrate and removing the first substrate; forming a first carrier layer on the surface of the at least two light-emitting units away from the second substrate; forming a second carrier layer on the surface of the first carrier layer away from the second substrate, such that the second carrier layer surrounds and encloses the sidewall of the first carrier layer, and removing the second substrate.

[0015] This disclosure provides a display panel, which includes a light-emitting functional layer and a driving backplane. The light-emitting functional layer is located on the driving backplane and is electrically connected to the driving backplane. The light-emitting functional layer includes a plurality of light-emitting devices as described above.

[0016] The beneficial effects of the technical solutions provided in this disclosure include at least the following:

[0017] The light-emitting device provided in this embodiment includes at least two light-emitting units, a bridging metal, and a first carrier layer. The at least two light-emitting units are spaced apart on the surface of the first carrier layer, and the bridging metal is located on the surface of the first carrier layer and at the gaps between the light-emitting units, connecting adjacent light-emitting units in series. This light-emitting device uses the first carrier layer as a supporting foundation. On one hand, the first carrier layer provides stable physical support for the bridging metal, effectively improving the overall support strength between the light-emitting units. In micro-display applications, even if the removal of the growth substrate weakens the mechanical strength of the epitaxial layer, the first carrier layer can still effectively support it, preventing the bridging metal from breaking due to lack of support and ensuring the connection reliability of the high-voltage LED series structure. On the other hand, the stable support structure ensures the integrity and conductivity of the bridging metal, allowing current to be transmitted efficiently and uniformly between the series-connected light-emitting units, reducing current loss or localized overheating caused by connection problems. This allows each light-emitting unit to emit light more fully under normal current, ultimately achieving an increase in overall brightness under the same current conditions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure;

[0020] Figure 2 This is a flowchart of a method for fabricating a light-emitting device according to an embodiment of this disclosure;

[0021] Figure 3 This is a fabrication state diagram of a light-emitting device provided in an embodiment of this disclosure;

[0022] Figure 4 This is a fabrication state diagram of a light-emitting device provided in an embodiment of this disclosure;

[0023] Figure 5 This is a fabrication state diagram of a light-emitting device provided in an embodiment of this disclosure;

[0024] Figure 6 This is a fabrication state diagram of a light-emitting device provided in an embodiment of this disclosure.

[0025] The markings in the diagram are explained as follows:

[0026] 1. Light-emitting unit;

[0027] 10. Epitaxial layer; 101. First semiconductor layer; 102. Multiple quantum well layer; 103. Second semiconductor layer;

[0028] 11. First insulating layer; 12. Second insulating layer;

[0029] 13. Electrode; 14. Pad;

[0030] 20. Bridging metal;

[0031] 31. First load-bearing layer; 32. Second load-bearing layer;

[0032] 41. First substrate; 42. Second substrate; 43. Third substrate;

[0033] 50. Photosensitive adhesive layer. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0035] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” “top,” and “bottom,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0036] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure. Figure 1 As shown, the light-emitting device includes: at least two light-emitting units 1, a bridging metal 20 and a first carrier layer 31. The at least two light-emitting units 1 are arranged at intervals on the surface of the first carrier layer 31. The bridging metal 20 is located on the surface of the first carrier layer 31 and is located in the gap between the at least two light-emitting units 1. The at least two light-emitting units 1 are connected in series through the bridging metal 20.

[0037] The light-emitting device provided in this embodiment includes at least two light-emitting units 1, a bridging metal 20, and a first support layer 31. The at least two light-emitting units 1 are spaced apart on the surface of the first support layer 31. The bridging metal 20 is located on the surface of the first support layer 31 and at the gaps between the light-emitting units 1, connecting adjacent light-emitting units 1 in series. This light-emitting device uses the first support layer 31 as a supporting foundation. On one hand, the first support layer 31 provides stable physical support for the bridging metal 20, effectively improving the overall support strength between the light-emitting units 1. In micro-display applications, even if the removal of the growth substrate weakens the mechanical strength of the epitaxial layer 10, the first support layer 31 can still effectively support it, preventing the bridging metal 20 from breaking due to lack of support, and ensuring the connection reliability of the high-voltage LED series structure. On the other hand, the stable support structure ensures the integrity and conductivity of the bridging metal 20, enabling the current to be transmitted efficiently and evenly between the series-connected light-emitting units 1, reducing current loss or local overheating caused by connection problems, thereby allowing each light-emitting unit 1 to emit light more fully under normal current, ultimately achieving an improvement in overall brightness under the same current conditions.

[0038] Optionally, such as Figure 1 As shown, the light-emitting device also includes a second carrier layer 32, which is located on the surface of the first carrier layer 31 away from at least two light-emitting units 1, and the second carrier layer 32 surrounds and encloses the sidewall of the first carrier layer 31.

[0039] Adding a second support layer 32 to the first support layer 31 enhances the three-dimensionality of the mechanical support. The second support layer 32 wraps around the sidewalls of the first support layer 31, forming a sandwich-like composite support structure. The first support layer 31 primarily bears the vertical pressure of the light-emitting unit 1 and the bridging metal 20, while the second support layer 32 laterally constrains the first support layer 31, preventing deformation or displacement due to lateral stress during cutting, packaging, or use. This three-dimensional support effectively disperses external mechanical stress, avoiding stress concentration that could lead to damage to the support layer or indirect damage to the bridging metal 20, further reducing the risk of breakage.

[0040] Furthermore, the design of the second carrier layer 32 surrounding the sidewall of the first carrier layer 31 can also prevent external corrosive substances such as moisture and oxygen from contacting the first carrier layer 31 and the internal light-emitting unit 1. Micro-display devices are typically sensitive to the environment, especially the light-emitting unit 1 and epitaxial layer 10 of small-sized Micro LEDs. If exposed to a humid or oxidizing environment, problems such as oxidation of the epitaxial layer 10 and corrosion of the metal electrode 13 may occur. The encapsulation structure of the second carrier layer 32 forms a physical barrier, which can improve the environmental tolerance of the light-emitting device and extend its service life.

[0041] Meanwhile, during chip cutting, testing, or subsequent packaging, the second carrier layer 32, as an outer protective layer, can provide additional process tolerance space for the first carrier layer 31 and the internal structure, reducing the risk of damage to the light-emitting unit 1 and the bridging metal 20 due to operational errors.

[0042] Optionally, the first load-bearing layer 31 includes an inorganic material layer.

[0043] The first supporting layer 31 is made of inorganic material. Because inorganic materials have high hardness, low coefficient of thermal expansion and excellent chemical stability, they can effectively support the light-emitting unit 1 and the bridging metal 20, resist mechanical stress and thermal stress, prevent breakage, and block water and oxygen penetration to protect the internal structure.

[0044] Optionally, the first carrier layer 31 includes at least one of a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, and a titanium oxide layer.

[0045] Among them, the silicon oxide layer has a moderate dielectric constant and a low coefficient of thermal expansion, and has good thermal matching with the epitaxial layer 10, which can effectively alleviate thermal stress; in addition, the silicon oxide layer has stable chemical properties, is resistant to acid and alkali corrosion, and can block water and oxygen penetration, protecting the light-emitting unit 1; at the same time, the silicon oxide layer also has a certain mechanical strength, providing basic support for the bridging metal 20.

[0046] Among them, the silicon nitride layer has high hardness, good wear resistance, and strong resistance to mechanical impact; and the silicon nitride layer has good ultraviolet light transmittance and does not affect the function of optoelectronic devices.

[0047] Among them, the aluminum oxide layer has a high thermal conductivity, which is better than most insulating materials, and can help dissipate heat and alleviate the local high temperature when the light-emitting unit 1 is working; and it has extremely strong chemical stability, which is not easy to decompose in high temperature and humid environment, and has high long-term reliability.

[0048] Among them, the titanium oxide layer has a high refractive index, which can optimize the optical reflection performance of the device and improve the light extraction efficiency.

[0049] For example, the first carrier layer 31 may include at least one silicon oxide layer and at least one silicon nitride layer stacked together.

[0050] The bottom layer is a silicon oxide layer with a thickness of 100nm to 200nm, which can provide a certain passivation effect; the upper layer is a silicon nitride layer with a thickness of 50nm to 100nm, which utilizes its high hardness and excellent passivation properties to provide double protection for bridging metal 20 and light-emitting unit 1.

[0051] For example, the first carrier layer 31 may include at least one layer of aluminum oxide and at least one layer of titanium oxide stacked together.

[0052] The bottom layer is an aluminum oxide layer with a thickness of 150nm to 300nm, which can enhance heat dissipation and chemical resistance; the top layer is a titanium oxide layer with a thickness of 50nm to 80nm, which can improve optical reflectivity and suppress surface contamination, thus balancing heat dissipation and light efficiency optimization.

[0053] Optionally, the thickness of the first bearing layer 31 is 1 μm to 5 μm.

[0054] By controlling the thickness of the first bearing layer 31 within the aforementioned range, sufficient mechanical strength can be provided to effectively disperse the vertical stress between the bridging metal 20 and the light-emitting unit 1, preventing breakage; while avoiding stress accumulation caused by excessive thickness, ensuring the structural stability of the light-emitting device.

[0055] For example, the thickness of the first carrier film is 3 μm.

[0056] The 3μm silicon oxide or silicon nitride layer can effectively bear the mechanical load of the micron-sized bridging metal 20 and prevent the bridging metal 20 from breaking. At the same time, the 3μm thickness of the first bearing film can reduce the risk of thermal mismatch with the epitaxial material and reduce warping deformation caused by temperature changes.

[0057] Optionally, grooves or protrusions may be provided on the surface of the first carrier layer 31 near the light-emitting device.

[0058] For example, the surface of the first carrier layer 31 is provided with a plurality of spaced grooves. The grooves can increase the interlayer contact area. For example, filling the grooves with the film material of the light-emitting device can form a mechanical interlock, thereby improving the interlayer bonding strength.

[0059] Optionally, the second support layer 32 includes an organic material layer.

[0060] The second carrier layer 32 is made of organic material. The good flexibility and adhesion of organic material allow it to tightly wrap around the sidewalls of the first carrier layer 31, buffering external impacts and providing additional protection. Furthermore, organic material is easy to process and mold, and has high compatibility with subsequent packaging processes. The combination of the first carrier layer 31 and the second carrier layer 32 achieves both high-strength support and environmental isolation, improving the reliability of the micro-display high-voltage LED.

[0061] Optionally, the second carrier layer 32 includes a photosensitive material layer.

[0062] For example, the photosensitive material layer can be a deep ultraviolet photoresist.

[0063] The deep ultraviolet photoresist can be decomposed by high-energy laser irradiation, achieving selective removal. Since the second carrier layer 32 will also come into contact with the substrate during the fabrication of the light-emitting device, the substrate can be quickly peeled off by providing a second carrier layer 32 that is easily photolyzed.

[0064] For example, the photosensitive material layer can be a polymeric photosensitive resin, such as an acrylate-based DUV resin. Under irradiation with a 248 nm or 266 nm laser, the photoinitiator absorbs energy to generate free radicals, which cause the polymer backbone to break or the cross-linked structure to be destroyed, resulting in the material softening, carbonizing or vaporizing, and finally being peeled off or dissolved by the laser.

[0065] Optionally, the thickness of the second carrier layer 32 can be from 5 μm to 20 μm.

[0066] In this process, the second support layer 32 needs to wrap around the sidewall of the first support layer 31 and provide lateral mechanical support. When the thickness of the second support layer 32 is <5μm, the constraint force of the wrapping layer on the sidewall is insufficient, making it difficult to effectively buffer lateral external forces. This can easily lead to damage to the first support layer 31 or the bridging metal 20 due to lateral stress concentration. If the thickness of the second support layer 32 is >20μm, it will increase the process complexity and may cause the overall device to warp due to stress accumulation, affecting the integration accuracy of the micro-display.

[0067] For example, the thickness of the second carrier layer 32 can be 10 μm. The 10 μm organic material layer can fully wrap the sidewalls of the first carrier layer 31 to form a continuous and dense lateral protective layer, effectively resisting lateral impacts during cutting and packaging processes and preventing the first carrier layer 31 from breaking due to lateral stress. At the same time, the 10 μm organic material layer will not excessively increase the overall height of the device, and the spin coating or coating process can easily achieve uniform coverage, resulting in a more uniform energy distribution during laser decomposition and ensuring the reliability of selective removal.

[0068] Optionally, the thickness of the bridging metal 20 is from 0.3 μm to 2 μm.

[0069] Controlling the thickness of the bridging metal 20 to ≥0.3μm ensures sufficient current carrying capacity to meet the series connection requirements of the light-emitting unit 1 under the micro-sized Micro LED, while reducing the amount of material used and the difficulty of step coverage, and avoiding the risk of bridging failure caused by uneven deposition of excessively thick metal on the sidewall of the micron-level isolation trench.

[0070] Meanwhile, by controlling the thickness of the bridging metal 20 to ≤2μm, sufficient mechanical strength can be maintained to resist thermal stress and mechanical impact during subsequent processes and use, and to prevent the bridging structure from breaking.

[0071] For example, the thickness of the bridging metal 20 can be 0.8 μm.

[0072] The 0.8μm metal layer can support stable transmission of low current density in micro-display applications, ensuring the brightness consistency of the light-emitting unit 1. At the same time, the mechanical strength of the 0.8μm metal layer is higher than that of the 0.3μm ultrathin layer, which can effectively resist stress impacts during processes such as substrate peeling and cutting, and reduce the probability of breakage.

[0073] Optionally, such as Figure 1 As shown, the light-emitting unit 1 includes: an epitaxial layer 10, a first insulating layer 11, at least two electrodes 13, a second insulating layer 12, and at least two pads 14.

[0074] like Figure 1 As shown, the epitaxial layer 10 includes a first semiconductor layer 101, a multiple quantum well layer 102, and a second semiconductor layer 103, which are sequentially stacked on the surface of the first carrier layer 31.

[0075] In this embodiment of the present disclosure, one of the first semiconductor layer 101 and the second semiconductor layer 103 is an n-type layer, and the other of the first semiconductor layer 101 and the second semiconductor layer 103 is a p-type layer.

[0076] For example, the first semiconductor layer 101 is an n-type layer and the second semiconductor layer 103 is a p-type layer.

[0077] Taking a blue light epitaxial structure as an example, the structure of each layer is illustrated. In the blue light epitaxial structure, the p-type layer includes a p-type GaN layer.

[0078] The multi-quantum-well layer 102 may include alternating InGaN quantum-well layers and GaN quantum-barrier layers. The third light-emitting layer may include alternating layers of 3 to 8 cycles of InGaN quantum-well layers and GaN quantum-barrier layers.

[0079] Among them, the n-type layer includes the n-type GaN layer.

[0080] Optionally, the thickness of the epitaxial layer 10 is 2 μm to 10 μm.

[0081] For example, the thickness of the epitaxial layer 10 is 6 μm.

[0082] like Figure 1 As shown, the surface of the second semiconductor layer 103 has a groove that exposes the first semiconductor layer 101. The first insulating layer 11 is located in the groove and on the surface of the second semiconductor layer 103.

[0083] Optionally, the first insulating layer 11 includes at least one of a silicon oxide layer, a silicon nitride layer, and a titanium oxide layer.

[0084] For example, the first insulating layer 11 may be a silicon oxide layer. The thickness of the silicon oxide layer may be 5000 angstroms.

[0085] like Figure 1As shown, at least two electrodes 13 are located on the surface of the first insulating layer 11 away from the epitaxial layer 10. The surface of the first insulating layer 11 has through-holes that expose the bottom of the groove and the second semiconductor layer 103, respectively. One electrode 13 is connected to the first semiconductor layer 101 through the through-hole, and the other electrode 13 is connected to the second semiconductor layer 103 through the through-hole.

[0086] Optionally, at least two electrodes 13 include a p-electrode 13 and an n-electrode 13. The p-electrode 13 is used to connect to the p-type layer, and the n-electrode 13 is used to connect to the n-type layer.

[0087] like Figure 1 As shown, a portion of the bridging metal 20 is connected to the p electrode 13 of one light-emitting unit 1, and another portion of the bridging metal 20 is connected to the n electrode 13 of another light-emitting unit 1.

[0088] like Figure 1 As shown, the second insulating layer 12 is located on the first insulating layer 11 and covers the electrode 13 and the bridging metal 20. The surface of the second insulating layer 12 has through holes that expose at least two electrodes 13 respectively.

[0089] The pads 14 correspond one-to-one with the electrodes 13. The pads 14 are located on the surface of the second insulating layer 12 and are connected to the corresponding electrodes 13 through through holes.

[0090] Optionally, both the first insulating layer 11 and the second insulating layer 12 may include multiple alternating layers of first material and multiple alternating layers of second material, wherein the refractive indices of the first material and the second material are different. By setting alternating layers of high and low refractive index material, a distributed Bragg reflector (DBR) can be formed.

[0091] For example, the first material layer may be a silicon dioxide layer with a refractive index of 1.44 to 1.55, and the second material layer may be a titanium dioxide layer with a refractive index of 2.2 to 2.9. The two material layers have a large difference in refractive index, and only 10 to 20 cycles of material layers are needed to achieve high reflectivity and low absorption loss in the visible light region.

[0092] Figure 2 This is a flowchart illustrating a method for fabricating a light-emitting device according to an embodiment of this disclosure. For example... Figure 2 As shown, the preparation method includes:

[0093] Step S11: Form at least two light-emitting units 1 spaced apart on the first carrier layer 31.

[0094] Step S12: A bridging metal 20 is formed on the surface of the first bearing layer 31.

[0095] The bridging metal 20 is located in the gap between at least two light-emitting units 1, and at least two light-emitting units 1 are connected in series through the bridging metal 20.

[0096] The light-emitting device fabricated by this method includes at least two light-emitting units 1, a bridging metal 20, and a first support layer 31. At least two light-emitting units 1 are spaced apart on the surface of the first support layer 31. The bridging metal 20 is located on the surface of the first support layer 31 and at the gaps between the light-emitting units 1, connecting adjacent light-emitting units 1 in series. This light-emitting device utilizes the first support layer 31 as a supporting foundation. On one hand, the first support layer 31 provides stable physical support for the bridging metal 20, effectively improving the overall support strength between the light-emitting units 1. In micro-display applications, even if the removal of the growth substrate weakens the mechanical strength of the epitaxial layer 10, the first support layer 31 can still effectively support it, preventing the bridging metal 20 from breaking due to lack of support, and ensuring the connection reliability of the high-voltage LED series structure. On the other hand, the stable support structure ensures the integrity and conductivity of the bridging metal 20, enabling the current to be transmitted efficiently and evenly between the series-connected light-emitting units 1, reducing current loss or local overheating caused by connection problems, thereby allowing each light-emitting unit 1 to emit light more fully under normal current, ultimately achieving an improvement in overall brightness under the same current conditions.

[0097] Step S11, in which the article is prepared, may specifically include the following steps:

[0098] The first step is to form at least two light-emitting units 1 on the first substrate 41.

[0099] For example, the first substrate 41 may be a sapphire substrate, a GaAs substrate, a silicon substrate, or a silicon carbide substrate.

[0100] like Figure 3 As shown, the specific process for preparing the light-emitting unit 1 may include:

[0101] First, an epitaxial layer 10 is formed on the surface of the first substrate 41.

[0102] For example, such as Figure 3 As shown, the epitaxial layer 10 includes a first semiconductor layer 101, a multiple quantum well layer 102, and a second semiconductor layer 103 stacked sequentially.

[0103] The epitaxial layer 10 may include: a first semiconductor layer 101, a multiple quantum well layer 102, and a second semiconductor layer 103 sequentially formed on a substrate using MOCVD technology.

[0104] In this process, one of the first semiconductor layer 101 and the second semiconductor layer 103 is an n-type layer, and the other of the first semiconductor layer 101 and the second semiconductor layer 103 is a p-type layer.

[0105] For example, the epitaxial layer 10 includes an n-type GaN layer, a multiple quantum well layer 102 and a p-type GaN layer stacked sequentially.

[0106] Optionally, the thickness of the n-type GaN layer can be from 0.5 μm to 3 μm.

[0107] The growth temperature of the n-type GaN layer can be from 1000℃ to 1100℃, and the growth pressure of the n-type GaN layer can be from 100 torr to 300 torr.

[0108] Optionally, the multi-quantum-well layer 102 includes alternating InGaN quantum well layers and GaN quantum barrier layers. Specifically, the multi-quantum-well layer 102 may include 3 to 8 alternating stacked InGaN quantum well layers and GaN quantum barrier layers.

[0109] When growing the multi-quantum-well layer 102, the MOCVD reaction chamber pressure was controlled at 200 torr. When growing the InGaN quantum well layer, the reaction chamber temperature was 760℃ to 780℃. When growing the GaN quantum barrier layer, the reaction chamber temperature was 860℃ to 890℃.

[0110] As an example, in an embodiment of this disclosure, the multi-quantum-well layer 102 includes five alternating stacked InGaN quantum-well layers and GaN quantum-barrier layers.

[0111] Optionally, the thickness of the multiple quantum well layer 102 can be from 150 nm to 200 nm.

[0112] Optionally, the thickness of the p-type GaN layer can be from 0.5 μm to 3 μm.

[0113] When growing p-type GaN layers, the growth pressure of p-type GaN layers can be from 200 Torr to 600 Torr, and the growth temperature of p-type GaN layers can be from 800℃ to 1000℃.

[0114] Then, as Figure 3 As shown, etching is performed on the surface of the second semiconductor layer 103 to form a groove that exposes at least the multiple quantum well layer 102.

[0115] Specifically, it may include: forming a mask on the surface of the second semiconductor layer 103 using photolithography, and then forming a groove on the surface of the second semiconductor layer 103 through the mask using plasma etching.

[0116] During the etching process, the power of the etching equipment is controlled at 300W to 600W, and the lower power is controlled at 100W to 300W.

[0117] For example, the groove depth is 1 μm to 2 μm.

[0118] Next, as Figure 3 As shown, a first insulating layer 11 covering the epitaxial layer 10 is formed on the first substrate 41.

[0119] Optionally, the first insulating layer 11 includes at least one of a silicon oxide layer, a silicon nitride layer, and a titanium oxide layer.

[0120] For example, the first insulating layer 11 may be a silicon oxide layer. The thickness of the silicon oxide layer may be 5000 angstroms.

[0121] Then, as Figure 3 As shown, the first insulating layer 11 is etched to form through holes on the surface of the first insulating layer 11 that expose the second semiconductor layer 103 and the groove, respectively.

[0122] Etching can be achieved through dry etching, or by combining photolithography with wet etching, such as etching with a mixed solution of H3PO4 / H2SO4, or by using laser front scribing.

[0123] Next, an electrode 13 is formed on the surface of the first insulating layer 11 away from the first substrate 41, and the electrode 13 is connected to the second semiconductor layer 103 and the first semiconductor layer 101 in the groove through through holes.

[0124] Specifically, this may include fabricating p-electrode 13 and n-electrode 13 using photolithography and evaporation methods.

[0125] The n-electrode 13 is located in the groove and is connected to the n-type layer through a through hole, while the p-electrode 13 is connected to the transparent conductive layer through a through hole.

[0126] Multiple light-emitting devices were prepared through the aforementioned steps.

[0127] The second step, as Figure 4 As shown, a photosensitive adhesive layer 50 covering at least two light-emitting units 1 is formed on the first substrate 41.

[0128] The third step, as Figure 4 As shown, the photosensitive adhesive layer 50 is bonded to the second substrate 42, and the first substrate 41 is removed.

[0129] The above two steps may specifically include: spin-coating photosensitive adhesive onto the first substrate 41 to form a photosensitive adhesive layer, and bonding the second substrate 42 to the photosensitive adhesive layer to ensure that there are no voids between the light-emitting units 1. Then, the first substrate 41 is removed to expose the first semiconductor layer 101.

[0130] Step four, as Figure 5 As shown, a first carrier layer 31 is formed on the surface of at least two light-emitting units 1 that is away from the second substrate 42.

[0131] Specifically, this may include: firstly, fabricating a first carrier layer 31 on the surface of the first semiconductor layer 101 using PECVD or ion-assisted evaporation. Then, etching the film between adjacent light-emitting units 1 using photolithography and ICP to expose the photosensitive adhesive layer.

[0132] For example, the first carrier layer 31 includes at least one of a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, and a titanium oxide layer.

[0133] For example, the thickness of the first carrier layer 31 is 1 μm to 5 μm.

[0134] Fifth step, as Figure 5 As shown, a second carrier layer 32 is formed on the surface of the first carrier layer 31 away from the second substrate 42, such that the second carrier layer 32 surrounds and encloses the sidewall of the first carrier layer 31, and the second substrate 42 is removed.

[0135] Specifically, this may include: spin-coating a photosensitive material onto the surface of the first carrier layer 31 away from the second substrate 42 to form the second carrier layer 32, and bonding a third substrate 43 to the surface of the second carrier layer 32; at the same time, peeling off the second substrate 42 using laser lift-off, and cleaning the photosensitive adhesive layer between the light-emitting devices using ICP or Plasma.

[0136] Optionally, the thickness of the second carrier layer 32 can be from 5 μm to 20 μm.

[0137] like Figure 6 As shown, step S12 may include: using photolithography and evaporation or sputtering to create bridging metal 20 between light-emitting devices to form a series connection.

[0138] For example, the thickness of the bridging metal 20 is 0.3 μm to 2 μm.

[0139] The following steps may also include:

[0140] First, such as Figure 6 As shown, a second insulating layer 12 covering the electrode 13 is formed on the first insulating layer 11 of the light-emitting device.

[0141] Optionally, the second insulating layer 12 may include multiple alternating layers of first material and multiple alternating layers of second material, wherein the refractive indices of the first and second material layers are different. By setting alternating layers of high and low refractive index material, a distributed Bragg reflector (DBR) can be formed.

[0142] For example, the first material layer may be a silicon dioxide layer with a refractive index of 1.44 to 1.55, and the second material layer may be a titanium dioxide layer with a refractive index of 2.2 to 2.9. The two material layers have a large difference in refractive index, and only 10 to 20 cycles of material layers are needed to achieve high reflectivity and low absorption loss in the visible light region.

[0143] Next, as Figure 6 As shown, the second insulating layer 12 is etched to form a through hole exposing the electrode 13 on the surface of the second insulating layer 12.

[0144] Etching can be achieved through dry etching, or by combining photolithography with wet etching, such as etching with a mixed solution of H3PO4 / H2SO4, or by using laser front scribing.

[0145] Then, pads 14 are formed on the surface of the second insulating layer 12, and the pads 14 are connected to the corresponding electrodes 13 through through holes.

[0146] The method for fabricating a light-emitting device provided in this embodiment employs a two-step transfer process. A first carrier layer 31 fabricated at the bottom of the light-emitting device serves as a support layer for the high-voltage chip bridging metal 20. Simultaneously, a second insulating layer 12 covers the bridging metal 20. This improves the support strength between the light-emitting devices, preventing breakage. Furthermore, the second insulating layer 12 provides insulation, preventing potential leakage during use. This high-voltage micro-sized light-emitting device can be used subsequently via laser lift-off or transfer, and it also enhances the brightness of the light-emitting device.

[0147] This disclosure provides a display panel including a light-emitting functional layer and a driving backplane. The light-emitting functional layer is located on the driving backplane and is electrically connected to the driving backplane. The light-emitting functional layer includes a plurality of light-emitting diodes as described above.

[0148] Optionally, the driving backplane can be a TFT (Thin Film Transistor) substrate. The driving backplane includes multiple driving circuits arranged in an array. Each driving circuit on the driving backplane includes at least two TFTs for controlling the light emission of the connected light-emitting layer.

[0149] For example, the driving circuit includes an active layer, a gate insulating layer, a gate layer, an interlayer dielectric layer, and a source / drain layer sequentially stacked on a substrate. The light-emitting layer is connected to the source / drain layer of the corresponding driving circuit.

[0150] The TFTs driving the backplane can be made of various materials such as polycrystalline silicon and metal oxides, and this embodiment does not impose any restrictions.

[0151] The display device can be any product or component with a display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0152] The above is not intended to limit this disclosure in any way. Although this disclosure has been disclosed above through embodiments, it is not intended to limit this disclosure. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this disclosure. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this disclosure without departing from the content of the technical solution of this disclosure shall still fall within the scope of the technical solution of this disclosure.

Claims

1. A light-emitting device, characterized in that, The light-emitting device includes at least two light-emitting units (1), a bridging metal (20), and a first carrier layer (31). The at least two light-emitting units (1) are arranged at intervals on the surface of the first carrier layer (31). The bridging metal (20) is located on the surface of the first carrier layer (31) and in the gap between the at least two light-emitting units (1). The at least two light-emitting units (1) are connected in series through the bridging metal (20).

2. The light-emitting device according to claim 1, characterized in that, The light-emitting device further includes a second carrier layer (32), which is located on the surface of the first carrier layer (31) away from the at least two light-emitting units (1) and surrounds the sidewall of the first carrier layer (31).

3. The light-emitting device according to claim 2, characterized in that, The first support layer (31) includes an inorganic material layer, and the second support layer (32) includes an organic material layer.

4. The light-emitting device according to claim 3, characterized in that, The first carrier layer (31) includes at least one of a silicon oxide layer, a silicon nitride layer, an aluminum oxide layer, and a titanium oxide layer.

5. The light-emitting device according to claim 3, characterized in that, The second carrier layer (32) includes a photosensitive material layer.

6. The light-emitting device according to any one of claims 1 to 5, characterized in that, The thickness of the first carrier layer (31) is 1 μm to 5 μm.

7. The light-emitting device according to any one of claims 1 to 5, characterized in that, The thickness of the bridging metal (20) is 0.3 μm to 2 μm.

8. A method for fabricating a light-emitting device, characterized in that, The preparation method includes: At least two light-emitting units are formed at intervals on the first carrier layer; A bridging metal is formed on the surface of the first carrier layer, the bridging metal being located in the gap between the at least two light-emitting units, and the at least two light-emitting units being connected in series through the bridging metal.

9. The preparation method according to claim 8, characterized in that, The formation of at least two light-emitting units spaced apart on the first carrier layer includes: At least two light-emitting units are formed on the first substrate; A photosensitive adhesive layer covering the at least two light-emitting units is formed on the first substrate; The photosensitive adhesive layer is bonded to the second substrate, and the first substrate is removed; A first support layer is formed on the surface of the at least two light-emitting units away from the second substrate; A second carrier layer is formed on the surface of the first carrier layer away from the second substrate, such that the second carrier layer surrounds the sidewall of the first carrier layer, and the second substrate is removed.

10. A display panel, characterized in that, The display panel includes a light-emitting functional layer and a driving backplate. The light-emitting functional layer is located on the driving backplate and is electrically connected to the driving backplate. The light-emitting functional layer includes a plurality of light-emitting devices as described in any one of claims 1 to 7.

Images