Light emitting unit, method of manufacturing the same, light emitting panel, and display device

Abstract

The embodiment of the present disclosure provides a light-emitting unit, a preparation method thereof, a light-emitting panel and a display device. The light-emitting unit comprises: an active layer having a first side surface and a second side surface arranged oppositely; a plurality of first columnar structures separated from each other and located on the first side surface of the active layer, a first groove being arranged between adjacent first columnar structures, and the first columnar structure comprising a first semiconductor layer; a plurality of second columnar structures separated from each other and located on the second side surface of the active layer, a second groove being arranged between adjacent second columnar structures, and the second columnar structure comprising a second semiconductor layer, and the plurality of second columnar structures corresponding to the plurality of first columnar structures one by one. The technical scheme of the present disclosure avoids etching loss of the active layer and improves performance.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to light-emitting units and their preparation methods, light-emitting panels, and display devices. Background Technology

[0002] The market size for emerging display technologies such as Augmented Reality (AR) and Virtual Reality (VR) is gradually increasing. AR / VR displays use light-emitting diode (LED) chips, which are directly bonded to the driver backplane via an epitaxial layer. As LED chip size decreases, the quantum well layer is more susceptible to etching damage during LED chip fabrication, reducing LED chip performance. Summary of the Invention

[0003] This disclosure provides a light-emitting unit and its preparation method, a light-emitting panel, and a display device to solve or alleviate one or more technical problems in the prior art.

[0004] As a first aspect of the present disclosure, an embodiment of the present disclosure provides a light-emitting unit, including:

[0005] An active layer having a first side surface and a second side surface disposed opposite to each other;

[0006] Multiple first columnar structures separated from each other are located on the first side surface of the active layer, and a first trench is provided between adjacent first columnar structures. The first columnar structure includes a first semiconductor layer.

[0007] Multiple second columnar structures, separated from each other, are located on the second side surface of the active layer. A second trench is provided between adjacent second columnar structures. Each second columnar structure includes a second semiconductor layer. Each of the multiple second columnar structures corresponds one-to-one with a multiple first columnar structures.

[0008] In some embodiments,

[0009] A first preset distance is provided between the bottom surface of the first trench and the first side surface of the active layer, the value of the first preset distance being in the range of 100nm to 150nm; and / or,

[0010] A second preset distance is provided between the bottom surface of the second trench and the second side surface of the active layer, and the value of the second preset distance is in the range of 100nm to 150nm.

[0011] In some embodiments,

[0012] A first semiconductor connection portion is disposed between the first side surface of the active layer and the plurality of first columnar structures, the first semiconductor connection portion and the first semiconductor layer being an integral structure; and / or,

[0013] A second semiconductor connection portion is provided between the second side surface of the active layer and the plurality of second columnar structures, and the second semiconductor connection portion and the second semiconductor layer are an integral structure.

[0014] In some embodiments, an isolation layer is also included, which fills the second trench.

[0015] In some embodiments, the second columnar structure further includes a first electrode layer located on the side of the second semiconductor layer opposite to the active layer.

[0016] In some embodiments, the first electrode layer includes an auxiliary electrode and a first electrode stacked together, the auxiliary electrode being closer to the second semiconductor layer relative to the first electrode, and the material of the auxiliary electrode including a transparent conductive material.

[0017] In some embodiments, the system further includes a passivation layer and a second electrode layer. The passivation layer is located on the side of the plurality of first columnar structures opposite to the active layer. The passivation layer has a plurality of first vias corresponding one-to-one with the plurality of first columnar structures. The orthogonal projection of the first vias on the active layer is located within the orthogonal projection of the corresponding first columnar structure on the active layer. The second electrode layer is located on the side of the passivation layer opposite to the active layer. The second electrode layer is coupled to the first semiconductor layer in the corresponding first columnar structure through the first vias.

[0018] As a second aspect of this disclosure, this disclosure provides a method for preparing a light-emitting unit, comprising:

[0019] A first structural layer, an active layer, and a second structural layer are sequentially grown on a substrate. The first structural layer includes a first semiconductor thin film, and the second structural layer includes a second semiconductor thin film.

[0020] A second trench is formed on the side surface of the second structural layer away from the active layer using a first etching process. The second structural layer is divided into a plurality of second columnar structures that are separated from each other by the second trench. The second columnar structure includes a second semiconductor layer.

[0021] After the substrate is stripped, a second etching process is used to form a first trench on the side of the first structural layer away from the active layer. The first structural layer is divided into a plurality of first columnar structures that are separated from each other by the first trench. The first columnar structure includes a first semiconductor layer.

[0022] In some embodiments,

[0023] The bottom surface of the first trench is located between two opposing surfaces of the first semiconductor thin film, parallel to the surface of the active layer; and / or,

[0024] The bottom surface of the second trench is located between two opposing surfaces of the second semiconductor thin film that are parallel to the surface of the active layer.

[0025] In some embodiments,

[0026] A first preset distance is provided between the bottom surface of the first trench and the surface of the first semiconductor thin film facing the active layer, the first preset distance being in the range of 100nm to 150nm; and / or,

[0027] A second preset distance is provided between the bottom surface of the second trench and the surface of the second semiconductor thin film facing the active layer, and the value of the second preset distance is in the range of 100nm to 150nm.

[0028] In some embodiments, the method further includes, prior to stripping the substrate:

[0029] A first flat layer is formed on the side of the plurality of second columnar structures away from the active layer. The first flat layer fills the second trench. The distance between the surface of the first flat layer away from the active layer and the active layer is greater than the distance between the surface of the second columnar structure away from the active layer and the active layer.

[0030] The first planarization layer is etched to expose the surface of the second columnar structure facing away from the active layer, while the first planarization layer remaining in the second trench forms an isolation layer.

[0031] In some embodiments, it also includes:

[0032] The surface of the second columnar structure facing away from the active layer is bonded to the driving backplate.

[0033] Remove the substrate.

[0034] In some embodiments, it also includes:

[0035] A passivation layer is formed on the side of the multiple first columnar structures away from the drive backplate. The passivation layer has multiple first vias that correspond one-to-one with the multiple first columnar structures. The orthogonal projection of the first via on the active layer is located within the orthogonal projection of the corresponding first columnar structure on the active layer.

[0036] A second electrode layer is formed on the side of the passivation layer away from the drive backplate, and the second electrode layer is coupled to the first semiconductor layer in the corresponding first columnar structure through a first via.

[0037] As a third aspect of the present disclosure, the present disclosure provides a light-emitting panel, including a driving backplate and a light-emitting unit according to any of the present disclosures.

[0038] As a fourth aspect of the present disclosure, the present disclosure provides a display device including a light-emitting panel according to any one of the present disclosures.

[0039] In some embodiments, the light-emitting panel includes a plurality of light-emitting devices, each light-emitting device including a corresponding first columnar structure, a second columnar structure and a portion of an active layer sandwiched between the first columnar structure and the second columnar structure, and the display device further includes a color generating structure located on the side of the light-emitting unit away from the driving backplate, the color generating structure corresponding to the light-emitting device.

[0040] The color generating structure includes a color conversion layer and / or a color filter, and the display device also includes a barrier wall located between adjacent color generating structures.

[0041] The technical solution of this disclosure embodiment includes a light-emitting unit comprising multiple light-emitting devices. Adjacent light-emitting devices have first columnar structures separated by a first trench, and adjacent light-emitting devices have second columnar structures separated by a second trench. The light-emitting portions of all the multiple light-emitting devices are located within a single, continuous active layer. Therefore, the first and second columnar structures in adjacent light-emitting devices are separated from each other, while the active layer is a continuous whole. This structure eliminates the need for etching the active layer during fabrication, thus avoiding etching damage and eliminating the need for sidewall repair of the active layer. This not only improves the performance of each light-emitting device in the light-emitting unit but also reduces the number of process steps and lowers costs.

[0042] The above overview is for illustrative purposes only and is not intended to be limiting in any way. Further aspects, embodiments, and features of this disclosure will become readily apparent from the accompanying drawings and the following detailed description, in addition to the illustrative aspects, embodiments, and features described above. Attached Figure Description

[0043] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments according to this disclosure and should not be construed as limiting the scope of this disclosure.

[0044] Figure 1 This is a cross-sectional schematic diagram of an LED in related technologies;

[0045] Figure 2 This is a cross-sectional schematic diagram of a light-emitting unit in one embodiment of the present disclosure;

[0046] Figure 3 This is a schematic diagram of the light-emitting unit after the second structural layer has been grown according to an embodiment of the present disclosure;

[0047] Figure 4 This is a schematic diagram of the light-emitting unit after the second trench is formed according to an embodiment of the present disclosure;

[0048] Figure 5This is a schematic diagram of a light-emitting unit after the first planarization layer has been formed according to an embodiment of the present disclosure;

[0049] Figure 6 This is a schematic diagram of the light-emitting unit after the isolation layer is formed according to an embodiment of the present disclosure.

[0050] Figure 7 This is a schematic diagram of the light-emitting unit and the driving backplate after bonding in an embodiment of the present disclosure;

[0051] Figure 8 This is a schematic diagram of the light-emitting unit after the substrate has been removed according to an embodiment of this disclosure;

[0052] Figure 9 This is a schematic diagram of the light-emitting unit after the first trench has been formed according to an embodiment of the present disclosure;

[0053] Figure 10 This is a schematic diagram of a light-emitting unit after a passivation layer has been formed according to an embodiment of the present disclosure;

[0054] Figure 11 This is a cross-sectional schematic diagram of a display device according to another embodiment of the present disclosure.

[0055] Explanation of reference numerals in the attached figures:

[0056] 10. First columnar structure; 11. First semiconductor layer; 12. Buffer layer; 20. Second columnar structure; 21. Second semiconductor layer; 22. Auxiliary electrode; 23. First electrode;

[0057] 30. Substrate; 31. Buffer film; 32. First semiconductor film; 33. Active layer; 34. Second semiconductor film; 35. Auxiliary electrode film; 36. First electrode film; 37. First planarization layer; 371. Isolation layer; 38. Passivation layer; 39. Second electrode layer; 41. First trench; 42. Second trench;

[0058] 50. Drive backplate; 100. Light-emitting unit; 200. Light-emitting device;

[0059] 60. Color generation structure; 61. Color conversion layer; 62. Color filter; 63. Second planarization layer. Detailed Implementation

[0060] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure, and different embodiments can be combined arbitrarily without conflict. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0061] The light-emitting diode (LED) in this disclosure can be a mini light-emitting diode (Mini LED) or a micro light-emitting diode (Micro LED).

[0062] Figure 1 This is a cross-sectional schematic diagram of an LED in related technologies. For example... Figure 1 As shown in the related technology, the display product uses a vertically structured LED, which is directly bonded to the silicon-based driving backplane 50 through an epitaxial layer. As the LED size decreases, the specific surface area increases rapidly. During LED fabrication, the etching process can easily damage the sidewalls of the quantum well layer, leading to increased ineffective recombination in the quantum well layer and consequently reducing device performance.

[0063] To improve performance, related technologies have incorporated sidewall repair steps into the LED fabrication process. Examples include using alkaline solutions to remove sidewall lattice defects, using acid solutions to remove oxygen dangling bonds on the sidewall surface, and using oxide and alumina films to passivate and protect the LED's epitaxial layer. However, the improvement in device performance from sidewall repair is limited, necessitating the development of a higher-performance LED device.

[0064] To address some problems in related technologies, this disclosure provides a light-emitting unit.

[0065] Figure 2 This is a cross-sectional schematic diagram of a light-emitting unit in one embodiment of this disclosure. For example... Figure 2 As shown, the light-emitting unit may include an active layer 33, a first columnar structure 10, and a second columnar structure 20. The active layer 33 has a first side surface 33a and a second side surface 33b disposed opposite to each other. There are multiple first columnar structures 10, which are separated from each other. The multiple first columnar structures 10 are located on the first side surface 33a of the active layer 33, and a first trench 41 is provided between adjacent first columnar structures 10. Each first columnar structure 10 includes a first semiconductor layer 11. There are multiple second columnar structures 20, which are separated from each other and located on the second side surface 33b of the active layer 33. A second trench 42 is provided between adjacent second columnar structures 20. Each second columnar structure 20 includes a second semiconductor layer 21. Each of the multiple second columnar structures 20 corresponds one-to-one with each of the multiple first columnar structures 10.

[0066] One of the first semiconductor layer 11 and the second semiconductor layer 21 can be a P-type doped semiconductor layer, and the other can be an N-type doped semiconductor layer. The P-type doped semiconductor layer can contain In... x Al y Ga1-x-y A p-type nitride semiconductor layer with the composition N(0≤x<1, 0≤y<1, 0≤x + y<1), and the p-type impurity can be magnesium. For example, the material of the p-type doped semiconductor layer can include p-type doped gallium nitride (GaN). The n-type doped semiconductor layer can include In x Al y Ga 1-x-y An n-type nitride semiconductor layer with the composition N(0≤x<1, 0≤y<1, 0≤x + y<1), and the n-type impurity can be silicon. For example, the material of the n-type doped semiconductor layer can include n-type doped gallium nitride (GaN).

[0067] The second semiconductor layer 21 can be a single-layer structure, but in some exemplary embodiments, it can have a multi-layer structure containing different compositions. The active layer 33 can have a multi-quantum well (MQW) structure, in which the quantum well layers and the quantum barrier layers are stacked alternately with each other. For example, the quantum well layers and the quantum barrier layers can respectively include In x Al y Ga 1-x-y N(0≤x≤1, 0≤y≤1, 0≤x + y≤1) with different compositions. In one example, the quantum well layer can include In x Ga 1-x N(0<x≤1), and the quantum barrier layer can include GaN or AlGaN. The active layer 33 is not limited to the MQW structure and can have a single quantum well (SQW) structure.

[0068] In the present disclosure, the first columnar structure 10 includes the first semiconductor layer 11, the second columnar structure 20 includes the second semiconductor layer 21, the first columnar structure 10 corresponds to the second columnar structure 20, and the orthographic projections of the first columnar structure 10 and the second columnar structure 20 on the active layer 33 at least partially overlap. For example, the orthographic projections of the first columnar structure 10 and the second columnar structure 20 on the active layer 33 can coincide. A part of the active layer 33 sandwiched by the corresponding first columnar structure 10 and the second columnar structure 20 can be called a light-emitting portion. The light-emitting unit includes a plurality of light-emitting devices 200, and the light-emitting devices 200 can be LEDs. The light-emitting device 200 includes the corresponding first columnar structure 10, the second columnar structure 20, and the light-emitting portion.

[0069] The light-emitting unit disclosed herein includes multiple light-emitting devices 200. Adjacent light-emitting devices 200 have first columnar structures 10 separated by a first trench 41, and adjacent light-emitting devices 200 have second columnar structures 20 separated by a second trench 42. The light-emitting portions of the multiple light-emitting devices 200 are all located within a single active layer 33. Therefore, the first columnar structures 10 and second columnar structures 20 of adjacent light-emitting devices 200 are separated from each other, while the active layer 33 is a continuous whole. This structure eliminates the need for etching the active layer 33 during fabrication, thus avoiding etching damage and eliminating the need for sidewall repair of the active layer 33. This not only improves the performance of each light-emitting device 200 in the light-emitting unit but also reduces the number of process steps and lowers costs.

[0070] In one embodiment, a first preset distance d1 is provided between the bottom surface of the first trench 41 and the first side surface 33a of the active layer 33, and the value of the first preset distance d1 is in the range of 100nm to 150nm. By setting the first preset distance d1 and setting d1 to 100nm to 150nm, the active layer 33 can be prevented from being etched during the etching of the first trench 41. For example, the first preset distance d1 can be 100nm, 110nm, 120nm, 130nm, 140nm, or 150nm.

[0071] If the first preset distance d1 is too small, there is a risk of etching the active layer 33 during the etching of the first trench 41; if the first preset distance d1 is too large, the adjacent first columnar structures 10 cannot be completely separated, affecting the device performance. Setting the first preset distance d1 to 100nm~150nm can not only completely separate the adjacent first columnar structures 10 and ensure the device performance, but also ensure that the active layer 33 will not be etched.

[0072] In one embodiment, a second preset distance d2 is provided between the bottom surface of the second trench 42 and the second side surface 33b of the active layer 33. The value of the second preset distance d2 is in the range of 100nm to 150nm. By setting the second preset distance d2 and setting d2 to 100nm to 150nm, etching of the active layer 33 can be prevented during the etching of the second trench 42. For example, the second preset distance d2 can be 100nm, 110nm, 120nm, 130nm, 140nm, or 150nm.

[0073] If the second preset distance d2 is too small, there is a risk of etching the active layer 33 during the etching of the second trench 42; if the second preset distance d2 is too large, the adjacent second columnar structures 20 cannot be completely separated, affecting the device performance. Setting the second preset distance d2 to 100nm~150nm can not only completely separate the adjacent second columnar structures 20 and ensure the device performance, but also ensure that the active layer 33 will not be etched.

[0074] like Figure 2 As shown, a first semiconductor connection portion 321 can be provided between the first side surface 33a of the active layer 33 and the plurality of first columnar structures 10, and the first semiconductor connection portion 321 and the first semiconductor layer 11 are integrally formed. This ensures that the active layer 33 will not be etched when the first trench 41 is etched.

[0075] A second semiconductor connection portion 341 is provided between the second side surface 33b of the active layer 33 and the plurality of second columnar structures 20. The second semiconductor connection portion 341 and the second semiconductor layer 21 are an integral structure, so that the active layer 33 will not be etched when the second trench 42 is etched.

[0076] The light-emitting unit may also include an insulating layer 371, such as Figure 2 As shown, the isolation layer 371 fills the second trench 42. The isolation layer 371 can be made of an insulating material, for example, it can be an insulating material including silicon, such as silicon oxide, silicon nitride, or silicon oxynitride. The isolation layer 371 can also be made of an insulating organic material, such as a silicon-containing insulating adhesive. By filling the second trench 42 with the isolation layer 371, adjacent second columnar structures 20 can be completely isolated, improving the performance of the light-emitting unit. Since the isolation layer 371 is filled in the second trench 42, it can also provide support for the second columnar structures 20, improving the structural stability of the light-emitting unit.

[0077] The second columnar structure 20 may further include a first electrode layer located on the side of the second semiconductor layer 21 opposite to the active layer 33. Exemplarily, the first electrode layer may include an auxiliary electrode 22 and a first electrode 23 stacked together, with the auxiliary electrode 22 closer to the second semiconductor layer 21 than the first electrode 23. The auxiliary electrode 22 may be made of a transparent conductive material. For example, the auxiliary electrode 22 may be made of at least one of indium tin oxide (ITO) and indium zinc oxide (IZO). The first electrode 23 may be made of a metallic material. The auxiliary electrode 22 facilitates hole diffusion and improves the light extraction performance of the LED.

[0078] For example, the surface of the isolation layer 371 away from the active layer 33 can be flush with the surface of the second columnar structure 20 away from the active layer 33. For instance, the surface of the isolation layer 371 away from the active layer 33 can be flush with the surface of the first electrode layer away from the active layer 33, which facilitates the bonding connection between the surface of the second columnar structure 20 away from the active layer 33 and the drive backplate 50.

[0079] like Figure 2 As shown, the light-emitting unit may further include a passivation layer 38 and a second electrode layer 39. The passivation layer 38 is located on the side of the plurality of first columnar structures 10 facing away from the active layer 33. The passivation layer 38 can enclose the first columnar structures 10 to prevent them from interfering with each other.

[0080] The passivation layer 38 has multiple first vias K1 corresponding one-to-one with the multiple first columnar structures 10. The orthogonal projection of the first via K1 onto the active layer 33 lies within the orthogonal projection of the corresponding first columnar structure 10 onto the active layer 33. The second electrode layer 39 is located on the side of the passivation layer 38 facing away from the active layer 33. The second electrode layer 39 is coupled to the first semiconductor layer 11 in the corresponding first columnar structure 10 through the first via K1, such as... Figure 2 As shown.

[0081] For example, the first electrode layer can be used as the P electrode of the LED, and the second electrode layer 39 can be used as the N electrode of the LED.

[0082] This disclosure also provides a method for preparing a light-emitting unit, including steps S11-S13.

[0083] In step S11, a first structural layer, an active layer 33, and a second structural layer are sequentially grown on the substrate 30. The first structural layer includes a first semiconductor thin film, and the second structural layer includes a second semiconductor thin film.

[0084] In step S12, a second trench 42 is formed on the side surface of the second structural layer away from the active layer 33 using a first etching process. The second structural layer is divided into a plurality of second columnar structures 20 that are separated from each other by the second trench 42. The second columnar structure 20 includes a second semiconductor layer 21.

[0085] In step S13, after the substrate 30 is stripped, a second etching process is used to form a first trench 41 on the side of the first structural layer away from the active layer 33. The first structural layer is divided into a plurality of first columnar structures 10 that are separated from each other by the first trench 41. The first columnar structure 10 includes a first semiconductor layer 11.

[0086] The method for fabricating the light-emitting unit disclosed herein involves etching a second trench 42 using a first etching process. The second structural layer is divided into multiple second columnar structures 20 that are separated from each other by the second trench 42. Therefore, the active layer 33 is not etched during the etching of the second trench 42. Similarly, a first trench 41 is etched using a second etching process. The first structural layer is divided into multiple first columnar structures 10 that are separated from each other by the first trench 41. Therefore, the active layer 33 is not etched during the etching of the first trench 41. This avoids etching damage to the active layer 33 during the fabrication of the light-emitting unit, reduces ineffective recombination in the active layer 33, and improves the performance of the light-emitting unit. Furthermore, it eliminates the need for subsequent sidewall repair of the active layer 33, reducing process steps and lowering costs.

[0087] It should be noted that after etching to form the second trench 42, the second semiconductor thin film forms the second semiconductor layer 21 located in the second structural layer; after etching to form the first trench 41, the first semiconductor thin film forms the first semiconductor layer 11 located in the first structural layer.

[0088] In one embodiment, during the etching process to form the second trench 42, the bottom surface of the second trench 42 may be located between two opposing surfaces of the second semiconductor thin film parallel to the surface of the active layer 33. For example, if the second semiconductor thin film includes two surfaces parallel to the surface of the active layer 33, and the bottom surface of the second trench 42 is located between the two surfaces of the second semiconductor thin film, the second semiconductor thin film will not be etched through, thus avoiding etching to the active layer 33.

[0089] During the etching process to form the first trench 41, the bottom surface of the first trench 41 can be located between two opposing surfaces of the first semiconductor thin film that are parallel to the surface of the active layer 33. For example, if the first semiconductor thin film includes two surfaces parallel to the surface of the active layer 33, the bottom surface of the first trench 41 can be located between the two surfaces of the first semiconductor thin film, thereby preventing the first semiconductor thin film from being etched through and avoiding etching to the active layer 33.

[0090] In one embodiment, a second preset distance is provided between the bottom surface of the second trench 42 and the surface of the second semiconductor thin film facing the active layer 33, and the value of the second preset distance is in the range of 100nm to 150nm.

[0091] In one embodiment, a first preset distance is provided between the bottom surface of the first trench 41 and the surface of the first semiconductor thin film facing the active layer 33, and the value of the first preset distance is in the range of 100nm to 150nm.

[0092] In one embodiment, prior to stripping the substrate 30, the method further includes: forming a first planarization layer 37 on the side of the plurality of second columnar structures 20 opposite to the active layer 33, the first planarization layer 37 filling the second trench 42, the distance between the surface of the first planarization layer 37 opposite to the active layer 33 and the active layer 33 being greater than the distance between the surface of the second columnar structure 20 opposite to the active layer 33 and the active layer 33; etching the first planarization layer 37 to expose the surface of the second columnar structure 20 opposite to the active layer 33, the first planarization layer 37 remaining in the second trench 42 forming an isolation layer 371.

[0093] The fabrication method of the light-emitting unit may further include: bonding the surface of the second columnar structure 20 away from the active layer 33 to the driving backplate 50; and peeling off the substrate 30.

[0094] For example, the fabrication method may further include: forming a passivation layer 38 on the side of the plurality of first columnar structures 10 away from the driving backplate 50, the passivation layer 38 having a plurality of first vias K1 corresponding one-to-one with the plurality of first columnar structures 10, the orthogonal projection of the first vias K1 on the active layer 33 being located within the orthogonal projection of the corresponding first columnar structure 10 on the active layer 33; forming a second electrode layer 39 on the side of the passivation layer 38 away from the driving backplate 50, the second electrode layer 39 being coupled to the first semiconductor layer 11 in the corresponding first columnar structure 10 through the first vias K1.

[0095] The following is through Figure 2 The fabrication process of the light-emitting unit shown further illustrates the technical solution of the embodiments of this disclosure. It is understood that the term "patterning" as used herein includes processes such as coating photoresist, mask exposure, development, etching, and photoresist stripping when the patterning material is inorganic or metallic; and processes such as mask exposure and development when the patterning material is organic. Evaporation, deposition, coating, and plating mentioned herein are all mature fabrication processes in related technologies.

[0096] A first structural layer, an active layer 33, and a second structural layer are sequentially grown on substrate 30, such as... Figure 3 As shown, Figure 3This is a schematic diagram of the light-emitting unit after the second structural layer has been grown according to an embodiment of the present disclosure. The substrate 30 can be a sapphire substrate, or it can be a substrate 30 made of other materials, such as a silicon substrate, an aluminum oxide substrate, a diamond substrate, etc. The first structural layer can include a first semiconductor thin film 32, and the second structural layer can include a second semiconductor thin film 34. The first structural layer can also include a buffer thin film 31, which is located between the first semiconductor thin film 32 and the substrate 30. For example, the buffer thin film 31 is grown on the substrate 30, and the first semiconductor thin film 32 is grown on the side of the buffer thin film 31 facing away from the substrate 30. The buffer thin film 31 can include a stacked aluminum nitride layer and an undoped gallium nitride layer, with the undoped gallium nitride layer located between the aluminum nitride layer and the first semiconductor thin film 32. Exemplarily, the aluminum nitride layer can also be replaced by an indium gallium nitride layer (InGaN). The second structural layer can also include an auxiliary electrode thin film 35 and a first electrode thin film 36, which can be sequentially located on the side of the second semiconductor thin film 34 facing away from the active layer 33. For example, a second semiconductor thin film 34, an auxiliary electrode thin film 35, and a first electrode thin film 36 are sequentially grown on the side of the active layer 33 facing away from the substrate 30. In one embodiment, the first semiconductor thin film 32 is N-type doped gallium nitride (N-GaN), and the second semiconductor thin film 34 is P-type doped gallium nitride (P-GaN).

[0097] A second trench 42 is formed on the surface of the second structural layer on the side opposite to the active layer 33 using a first etching process, such as... Figure 4 As shown, Figure 4This is a schematic diagram of the light-emitting unit after the second trench is formed according to an embodiment of this disclosure. A first etching process is used to etch the auxiliary electrode film 35, the first electrode film 36, and the second semiconductor film 34 to form the second trench 42. During the etching process, it is ensured that the bottom surface of the second trench 42 is located between the upper and lower surfaces of the second semiconductor film 34, without etching through the second semiconductor film 34. For example, the distance between the etching depth and the upper surface of the active layer 33 is 100nm to 150nm. That is, the second preset distance between the bottom surface of the second trench 42 and the upper surface of the active layer 33 (i.e., the second side surface 33b) is in the range of 100nm to 150nm, or the second preset distance d2 between the bottom surface of the second trench 42 and the surface of the second semiconductor film 34 facing the active layer 33 is in the range of 100nm to 150nm. This ensures that the active layer 33 is not etched through, avoiding etching damage to the active layer 33. During the formation of the second trench 42, the auxiliary electrode thin film 35 can be etched using either dry or wet etching processes; the second semiconductor thin film 34 can be etched using inductively coupled plasma (ICP), and the etching gas can include chlorine (Cl2) and BCl3. After the second trench 42 is formed, the second structural layer is divided by the second trench 42 into a plurality of mutually separated second columnar structures 20. The second columnar structure 20 includes a second semiconductor layer 21, an auxiliary electrode layer 22, and a first electrode 23 stacked sequentially.

[0098] A first planarization layer 37 is formed on the side of the plurality of second columnar structures 20 opposite to the active layer 33. The first planarization layer 37 fills the second trench 42, such as Figure 5 As shown, Figure 5 This is a schematic diagram of a light-emitting unit after the formation of the first planarization layer according to an embodiment of the present disclosure. An insulating adhesive can be applied to the side of the second columnar structure 20 opposite to the active layer 33 using a coating process, and after curing, the first planarization layer 37 is formed. The distance between the surface of the first planarization layer 37 opposite to the active layer 33 (i.e., the upper surface of the first planarization layer 37) and the active layer 33 is greater than the distance between the surface of the second columnar structure 20 opposite to the active layer 33 (the upper surface of the second columnar structure 20) and the active layer 33. In other words, the upper surface of the first planarization layer 37 is higher than the upper surface of the second columnar structure 20. Figure 5As shown. Exemplarily, the distance d3 between the upper surface of the first planarization layer 37 and the upper surface of the second columnar structure 20 can be 0.8 μm to 1.5 μm, for example, d3 can be 0.8 μm, 1.0 μm, 1.2 μm, or 1.5 μm, etc. When forming the first planarization layer 37, setting the upper surface of the first planarization layer 37 to be higher than the upper surface of the second columnar structure 20 ensures that the first planarization layer 37 completely fills the second trench 42. The material of the first planarization layer 37 may include a silicon insulating material; for example, the material of the first planarization layer 37 is a silicon-based insulating adhesive.

[0099] The first planarization layer 37 is etched to expose the surface of the second columnar structure 20 facing away from the active layer 33, while the first planarization layer 37 remaining in the second trench 42 forms an isolation layer 371, as shown. Figure 6 As shown, Figure 6 This is a schematic diagram of the light-emitting unit after the isolation layer is formed according to an embodiment of the present disclosure. Exemplarily, the first planarization layer 37 can be etched using an ICP etching process to expose the first electrode 23 in the second columnar structure 20. Exemplarily, the upper surface of the isolation layer 371 can be flush with the upper surface of the second columnar structure 20, which not only ensures that the isolation layer 371 fills the second trench 42, but also exposes the surface of the second electrode.

[0100] The second electrode is bonded to the metal traces on the drive backplane 50, such as... Figure 7 As shown, Figure 7 This is a schematic diagram of the light-emitting unit and the driving backplate after bonding in an embodiment of the present disclosure. A bonding metal layer 51 can be prepared on the surface of the second electrode and on the metal trace surface of the driving backplate 50, respectively. The material of the bonding metal layer 51 may include gold-tin alloy (AuSn), gold-indium alloy (AuIn), indium-copper alloy (CuIn), or copper-tin alloy (CuSn), etc.; then, the bonding metal on the surface of the second electrode is bonded to the bonding metal on the metal trace of the driving backplate 50.

[0101] The substrate 30 is peeled off from the first structural layer using a peeling process, such as... Figure 8 As shown, Figure 8 This is a schematic diagram of the light-emitting unit after the substrate 30 has been removed in an embodiment of the present disclosure.

[0102] A second etching process is used to form a first trench 41 on the surface of the first structural layer away from the active layer 33, such as... Figure 9 As shown, Figure 9This is a schematic diagram of the light-emitting unit after the formation of the first trench in an embodiment of this disclosure. A second etching process is used to etch the buffer film 31 and the first semiconductor film 32 to form the first trench 41. During the etching process, it is ensured that the bottom surface of the first trench 41 is located between the upper and lower surfaces of the first semiconductor film 32, without etching through the first semiconductor film 32. For example, the distance between the etching depth and the upper surface of the active layer 33 is 100nm to 150nm. That is, the first preset distance d1 between the bottom surface of the first trench 41 and the upper surface of the active layer 33 (i.e., the first side surface 33a) is in the range of 100nm to 150nm, or the first preset distance d1 between the bottom surface of the first trench 41 and the surface of the first semiconductor film facing the active layer 33 is in the range of 100nm to 150nm. This ensures that the active layer 33 is not etched through, avoiding etching damage to the active layer 33. Inductively coupled plasma (ICP) etching can be used, and the etching gas can include chlorine (Cl2) and BCl3. After the first trench 41 is formed, the first structural layer is divided by the first trench 41 into a plurality of first columnar structures 10 that are separated from each other. The first columnar structure 10 includes a first semiconductor layer 11 and a buffer layer 12 stacked in sequence.

[0103] A passivation layer 38 is formed on the side of the plurality of first columnar structures 10 facing away from the drive backplate 50, such as Figure 10 As shown, Figure 10 This is a schematic diagram of a light-emitting unit after the formation of a passivation layer according to an embodiment of the present disclosure. Exemplarily, a passivation film is deposited on the side of the plurality of first columnar structures 10 facing away from the driving backplate 50; the passivation film is patterned to form a passivation layer 38. The passivation layer 38 has a plurality of first vias K1 corresponding one-to-one with the plurality of first columnar structures 10. The orthogonal projection of the first via K1 onto the active layer 33 lies within the orthogonal projection of the corresponding first columnar structure 10 onto the active layer 33. The buffer layer 12 or the first semiconductor layer 11 in the first columnar structure 10 is exposed through the first via K1, such as... Figure 10 As shown. The passivation layer 38 can be any one or more of silicon oxide (SiOx), silicon nitride (SiNx), and silicon oxynitride (SiON), and can be a single layer, multiple layers, or a composite layer.

[0104] A second electrode layer 39 is formed on the side of the passivation layer 38 facing away from the drive backplate 50. The second electrode layer 39 is coupled to the first semiconductor layer 11 in the corresponding first columnar structure 10 through a first via K1, such as... Figure 2 As shown. The second electrode layer 39 can be made of a transparent conductive material, such as ITO or IZO.

[0105] For example, a metal mesh can also be formed on the side of the second electrode layer 39 opposite to the driving backplate 50. The metal mesh can adopt a stacked structure, for example, a Ti / Al / Ti or Cr / Pt / Au stacked structure. Wherein, Ti is titanium, Al is aluminum, Cr is chromium, Pt is platinum, and Au is gold.

[0106] This disclosure also provides a light-emitting panel, such as... Figure 2 As shown, the light-emitting panel includes a driving backplate 50 and a light-emitting unit in any embodiment of this disclosure. The surface of the second columnar structure 20 in the light-emitting unit facing away from the active layer 33 is bonded to the driving backplate 50.

[0107] In this disclosure, during the fabrication of the light-emitting unit, the first electrode 23 in the second columnar structure 20 of the light-emitting unit is bonded to the driving backplate 50, thereby forming the first trench 41 and the first columnar structure 10. Therefore, the light-emitting panel is fabricated simultaneously with the light-emitting unit. Figure 2 This can also be a schematic diagram of the light-emitting panel in one embodiment of this disclosure. Figures 3-10 The process of fabricating the light-emitting unit can be understood as the process of fabricating the light-emitting panel. The light-emitting side of the light-emitting panel can be the side of the light-emitting unit that is away from the driving backplate 50.

[0108] The light-emitting panel in this embodiment can be used as a display panel in a display device, or it can be used as a light source in a display device.

[0109] The light-emitting panel in this embodiment can also be used as a light source in lighting products.

[0110] This disclosure also provides a display device, which includes the light-emitting panel in any embodiment of this disclosure.

[0111] Figure 11 This is a cross-sectional schematic diagram of a display device according to another embodiment of this disclosure. Figure 11 As shown, the display device may further include a color generating structure 60 located on the side of the light-emitting unit 100 opposite to the driving backplate 50, and the color generating structure 60 corresponds to the light-emitting device 200. For example, multiple color generating structures 60 are arranged in a one-to-one correspondence with multiple light-emitting devices 200.

[0112] In one embodiment, the color generating structure 60 includes a color filter 62. Exemplarily, the plurality of color filters 62 may include a first color filter 62a, a second color filter 62b, and a third color filter 62c, wherein the first color filter 62a, the second color filter 62b, and the third color filter 62c are respectively configured to correspond one-to-one with the three light-emitting areas in the light-emitting unit.

[0113] Color filter 62 can filter light, allowing corresponding light to pass through while filtering out other colors. First color filter 62a allows first-color light to pass through while filtering out other colors; second color filter 62b allows second-color light to pass through while filtering out other colors; third color filter 62c allows third-color light to pass through while filtering out other colors. Color display can be achieved by setting color filter 62.

[0114] The color generating structure 60 may further include a color conversion layer 61. When the color generating structure 60 includes a color conversion layer 61 and a color filter 62, the color conversion layer 62 may be located between the corresponding light-emitting device 200 and the color filter 62. Multiple color conversion layers 61 may include a first color conversion layer 61a, a second color conversion layer 61b, and a third color conversion layer 61c. The third color conversion layer 61c is used to allow third-color light to pass through, the second color conversion layer 61b can convert the third-color light into second-color light, and the first color conversion layer 61a can convert the third-color light into first-color light. The first color conversion layer 61a, the second color conversion layer 61b, and the third color conversion layer 61c are respectively configured in a one-to-one correspondence with the three light-emitting devices 200 in the light-emitting unit. The first color filter 62a, the second color filter 62b, and the third color filter 62c are configured in a one-to-one correspondence with the first color conversion layer 61a, the second color conversion layer 61b, and the third color conversion layer 61c.

[0115] Color conversion layer 61 may include quantum dots. For example, first color conversion layer 61a may include first-color quantum dots, and second color conversion layer 61b may include second-color quantum dots. The first-color quantum dots may be red quantum dots, and the second-color quantum dots may be green quantum dots. Third color conversion layer 61c may include scatter particles, which can improve the uniformity of the corresponding light-emitting area. Exemplarily, first color conversion layer 61a may include scatter particles; second color conversion layer 61b may include scatter particles. The particle size of the scatter particles in each color conversion layer can be set as needed.

[0116] like Figure 11 As shown, the display device may further include a barrier 64, which is located on the side of the light-emitting unit 100 away from the driving back plate 50, and is located between adjacent color generating structures 60. The barrier 64 can prevent crosstalk between light from adjacent light-emitting devices.

[0117] In one embodiment, the display device may further include a second planarization layer 63, which is located on the side of the light-emitting unit opposite to the driving backplate 50. For example, the second planarization layer 63 is located on the side of the second electrode layer 39 opposite to the driving backplate 50. The color conversion layer 62, the color filter layer 63, and the barrier 64 are all located on the side of the second planarization layer 63 opposite to the driving backplate 50, that is, the color conversion layer 62, the color filter layer 63, and the barrier 64 are all located on the flat surface of the second planarization layer 63.

[0118] The manufacturing process of a display device may include the following steps.

[0119] refer to Figure 11 A second planarization layer 63 is formed on the side of the second electrode layer 39 opposite to the drive backplate 50. The material of the second planarization layer 63 can be an organic material. The thickness d3 of the second planarization layer 63 can be less than or equal to 2 μm.

[0120] A barrier 64 is formed on the side of the second planarization layer 63 facing away from the driving backplate 50. For example, a light-shielding film can be formed on the side of the second planarization layer 63 facing away from the driving backplate 50 using a coating process, and then the light-shielding film can be patterned using an exposure and development process to form a barrier 64 located between adjacent light-emitting areas. An opening is formed between the barrier 64, and the opening corresponds to the light-emitting device. A first color conversion layer 61a, a second color conversion layer 61b, and a third color conversion layer 61c are filled into the corresponding openings, respectively. Each color conversion layer can be formed by printing or a patterning process.

[0121] A corresponding color filter 62 is formed on the side of each color conversion layer 61 away from the driving backplate 50. The first color conversion layer 61a, the second color conversion layer 61b and the third color conversion layer 61c correspond to the first color filter 62a, the second color filter 62b and the third color filter 62c, respectively.

[0122] In one embodiment, the color filter 62 can be a photoresist material of the corresponding color. For example, the first color filter 62a, the second color filter 62b, and the third color filter 62c can be the first color photoresist, the second color photoresist, and the third color photoresist, respectively.

[0123] In one embodiment, the first color filter 62a may include a first distributed Bragg reflector (DBR layer) configured to reflect a third color light while allowing the first color light to pass through.

[0124] In one embodiment, the second color filter 62b may include a second distributed Bragg reflector (DBR layer) configured to reflect a third color light while allowing the second color light to pass through.

[0125] For example, the first color light can be red light, the second color light can be green light, and the third color light can be blue light. The light-emitting device 200 of the light-emitting unit can emit blue light.

[0126] It is understandable that in the display device, the areas corresponding to the first color filter 62a, the second color filter 62b, and the third color filter 62c can be called R sub-pixels (red sub-pixels), G sub-pixels (green sub-pixels), and B sub-pixels (blue sub-pixels), respectively.

[0127] Figure 11 The example shows the positions of three sub-pixels R, G, and B. It is understood that the positions of these three sub-pixels can be set as needed and are not limited to... Figure 11 The arrangement method in the middle.

[0128] 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, navigator, VR device, AR device, etc.

[0129] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0130] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "multiple" means two or more, unless otherwise explicitly specified.

[0131] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0132] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0133] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this disclosure. To simplify this disclosure, the components and arrangements of specific examples are described above. Of course, these are merely examples and are not intended to limit this disclosure. Furthermore, reference numerals and / or reference letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0134] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this disclosure. Different parts of different embodiments can be combined with each other without conflict, and these should all be covered within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A light-emitting unit, characterized in that, include: An active layer having a first side surface and a second side surface disposed opposite to each other; Multiple first columnar structures, separated from each other, are located on the first side surface of the active layer, and a first trench is provided between adjacent first columnar structures. Each first columnar structure includes a first semiconductor layer. Multiple second columnar structures, separated from each other, are located on the second side surface of the active layer. A second trench is provided between adjacent second columnar structures. Each second columnar structure includes a second semiconductor layer. The multiple second columnar structures correspond one-to-one with the multiple first columnar structures.

2. The light-emitting unit according to claim 1, characterized in that, A first preset distance is provided between the bottom surface of the first trench and the first side surface of the active layer, the value of the first preset distance being in the range of 100nm to 150nm; and / or, A second preset distance is provided between the bottom surface of the second trench and the second side surface of the active layer, and the value of the second preset distance is in the range of 100nm to 150nm.

3. The light-emitting unit according to claim 1, characterized in that, A first semiconductor connection portion is disposed between the first side surface of the active layer and the plurality of first columnar structures, the first semiconductor connection portion and the first semiconductor layer being an integral structure; and / or A second semiconductor connection portion is provided between the second side surface of the active layer and the plurality of second columnar structures, and the second semiconductor connection portion and the second semiconductor layer are integral structures.

4. The light-emitting unit according to claim 1, characterized in that, It also includes an isolation layer that fills the second trench.

5. The light-emitting unit according to any one of claims 1-4, characterized in that, The second columnar structure also includes a first electrode layer located on the side of the second semiconductor layer opposite to the active layer.

6. The light-emitting unit according to claim 5, characterized in that, The first electrode layer includes an auxiliary electrode and a first electrode stacked together. The auxiliary electrode is closer to the second semiconductor layer relative to the first electrode. The material of the auxiliary electrode includes a transparent conductive material.

7. The light-emitting unit according to any one of claims 1-4, characterized in that, It also includes a passivation layer and a second electrode layer. The passivation layer is located on the side of the plurality of first columnar structures opposite to the active layer. The passivation layer has a plurality of first vias corresponding one-to-one with the plurality of first columnar structures. The orthographic projection of the first via on the active layer is located within the orthographic projection of the corresponding first columnar structure on the active layer. The second electrode layer is located on the side of the passivation layer opposite to the active layer, and the second electrode layer is coupled to the first semiconductor layer in the corresponding first columnar structure through the first via.

8. A method for preparing a light-emitting unit, characterized in that, include: A first structural layer, an active layer, and a second structural layer are sequentially grown on a substrate. The first structural layer includes a first semiconductor thin film, and the second structural layer includes a second semiconductor thin film. A second trench is formed on the side of the second structural layer away from the active layer using a first etching process. The second structural layer is divided into a plurality of second columnar structures that are separated from each other by the second trench. The second columnar structure includes a second semiconductor layer. After the substrate is stripped, a second etching process is used to form a first trench on the side of the first structural layer away from the active layer. The first structural layer is divided into a plurality of first columnar structures that are separated from each other by the first trench. The first columnar structure includes a first semiconductor layer.

9. The method according to claim 8, characterized in that, The bottom surface of the first trench is located between two opposing surfaces of the first semiconductor thin film that are parallel to the surface of the active layer; and / or, The bottom surface of the second trench is located between two opposing surfaces of the second semiconductor thin film that are parallel to the surface of the active layer.

10. The method according to claim 9, characterized in that, A first preset distance is provided between the bottom surface of the first trench and the surface of the first semiconductor thin film facing the active layer, the value of the first preset distance being in the range of 100nm to 150nm; and / or, A second preset distance is provided between the bottom surface of the second trench and the surface of the second semiconductor thin film facing the active layer, and the value of the second preset distance is in the range of 100nm to 150nm.

11. The method according to claim 8, characterized in that, Before stripping the substrate, the method further includes: A first flat layer is formed on the side of the plurality of second columnar structures opposite to the active layer. The first flat layer fills the second trench. The distance between the surface of the first flat layer opposite to the active layer and the active layer is greater than the distance between the surface of the second columnar structure opposite to the active layer and the active layer. The first planarization layer is etched to expose the surface of the second columnar structure facing away from the active layer, and the first planarization layer retained in the second trench forms an isolation layer.

12. The method according to claim 8, characterized in that, Also includes: The surface of the second columnar structure opposite to the active layer is bonded to the driving backplate; The substrate is peeled off.

13. The method according to claim 12, characterized in that, Also includes: A passivation layer is formed on the side of the plurality of first columnar structures opposite to the drive back plate. The passivation layer has a plurality of first vias corresponding to the plurality of first columnar structures. The orthographic projection of the first via on the active layer is located within the orthographic projection of the corresponding first columnar structure on the active layer. A second electrode layer is formed on the side of the passivation layer opposite to the drive backplate, and the second electrode layer is coupled to the first semiconductor layer in the corresponding first columnar structure through the first via.

14. A light-emitting panel, characterized in that, It includes a driving backplate and a light-emitting unit as described in any one of claims 1-7.

15. A display device, characterized in that, Includes the light-emitting panel as described in claim 14.

16. The display device according to claim 15, characterized in that, The light-emitting panel includes multiple light-emitting devices, each light-emitting device including a corresponding first columnar structure, a second columnar structure, and a portion of an active layer sandwiched between the first columnar structure and the second columnar structure. The display device also includes a color generating structure located on the side of the light-emitting unit away from the driving backplate, the color generating structure corresponding to the light-emitting device. The color generating structure includes a color conversion layer and / or a color filter, and the display device further includes a barrier wall located between adjacent color generating structures.

Images