Light emitting diode device, display panel, display device and manufacturing method

Abstract

The embodiment of the present disclosure provides a light emitting diode device, a display panel, a display device and a manufacturing method. The light emitting diode device comprises a substrate (1), a first electrode (2) located on one side of the substrate (1), a carrier functional layer (3) located on the side of the first electrode (2) away from the substrate (1), a quantum dot light emitting layer (4) located on the side of the carrier functional layer (3) away from the first electrode (2), and the quantum dot light emitting layer (4) has a molecular chain structure inside, wherein the molecular chain structure is formed by an atom transfer radical polymerization reaction of a first reactant and a modified molecule, the first reactant is subjected to an atom transfer radical polymerization reaction with the modified molecule through a ligand molecule A, and the modified molecule is in an initial state of being connected to one side of the carrier functional layer (3) facing the quantum dot light emitting layer (4); and a second electrode (5) located on the side of the quantum dot light emitting layer (4) away from the carrier functional layer (3).

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a light-emitting diode device, a display panel, a display device, and a method for manufacturing it. Background Technology

[0002] With the continuous development and evolution of nanoscience and technology, the fabrication of nanomaterials with specific patterned structures has gradually become an increasingly important research direction in the field of modern nanoscience and technology. As a novel nanomaterial, quantum dots have attracted widespread attention from researchers due to their numerous advantages since their emergence. The successful fabrication of quantum dot layers with specific patterns has not only expanded their application scope but also sparked another wave of research enthusiasm in the nanotechnology community. Quantum dot light-emitting diode (QLED) displays are a new type of display technology developed based on organic light-emitting diode (OLED) displays. The difference between the two is that the light-emitting layer in QLEDs is a quantum dot layer. Its principle is that electrons / holes are injected into the quantum dot layer through an electron / hole transport layer, and then recombine and emit light within the quantum dot layer. Compared with OLED display devices, QLEDs have advantages such as narrow emission peaks, high color saturation, and wide color gamut. Summary of the Invention

[0003] This disclosure provides a light-emitting diode device, comprising:

[0004] Substrate;

[0005] The first electrode is located on one side of the substrate.

[0006] A charge carrier functional layer is located on the side of the first electrode opposite to the substrate.

[0007] A quantum dot luminescent layer is located on the side of the charge carrier functional layer opposite to the first electrode. The quantum dot luminescent layer has a molecular chain structure, wherein the molecular chain structure is formed by an atom transfer radical polymerization reaction between a first reactant and a modifying molecule. The first reactant includes a quantum dot body and a ligand molecule A connected to the quantum dot body. The first reactant undergoes an atom transfer radical polymerization reaction with the modifying molecule through the ligand molecule A. The modifying molecule is initially connected to the side of the charge carrier functional layer facing the quantum dot luminescent layer.

[0008] The second electrode is located on the side of the quantum dot light-emitting layer opposite to the carrier functional layer.

[0009] In one possible implementation, the general formula of the ligand molecule A is:

[0010]

[0011] In this group, R1 is an electron-donating group and R2 is a solubilizing group.

[0012] In one possible implementation, R1 includes one of the following:

[0013]

[0014]

[0015] -S-.

[0016] In one possible implementation, R2 includes one of the following:

[0017] -(CH2) n1 -;

[0018]

[0019] Where 1≤n1≤8, 1≤m1≤8.

[0020] In one possible implementation, the general formula of the modified molecule is:

[0021]

[0022] Wherein, R3 is a group that couples with the surface of the carrier functional layer, R6 is a halogenated group, and R5 is an electron-donating group.

[0023] In one possible implementation, R3 includes one of the following:

[0024]

[0025]

[0026] In one possible implementation, R6 includes one of the following:

[0027] -Cl;

[0028] -Br;

[0029] -I.

[0030] In one possible implementation, R5 includes one of the following:

[0031]

[0032] -O-;

[0033]

[0034] -S-.

[0035] In one possible implementation, R4 includes one of the following:

[0036] -(CH2) n2 - where 1≤n2≤12.

[0037] In one possible implementation, the first reactant comprises ligand molecule B, the general formula of which is:

[0038]

[0039] Wherein, 1≤n3≤12, 1≤m3≤12, R9 is a group that coordinates with the quantum dot body, and R11 is a group that forms hydrogen bonds with the intermediate substrate when the quantum dot light-emitting layer is transferred.

[0040] In one possible implementation, R9 includes one of the following:

[0041] -NH2;

[0042] -SH;

[0043] -COOH.

[0044] In one possible implementation, R11 includes one of the following:

[0045] -CHO;

[0046] -OH;

[0047] -COOH.

[0048] In one possible implementation, R7 includes one of the following:

[0049] -O-;

[0050] -N-;

[0051] -C-;

[0052] -S-.

[0053] In one possible implementation, R8 includes one of the following:

[0054] -(CH2) a - where a = 1, 2, 3 or 4.

[0055] In one possible implementation, R10 includes one of the following:

[0056] -(CH2) b -;

[0057] Where 1≤b≤8, c=1 or 2.

[0058] In one possible implementation, the structure of the quantum dot body to which the ligand molecule A is attached is as follows:

[0059]

[0060] The modified molecule is:

[0061]

[0062] The chain initiation reaction occurring on the surface of the quantum dot luminescent layer facing the charge carrier functional layer is as follows:

[0063]

[0064] In one possible implementation, the molecular chain structure is as follows:

[0065] Where n4≥1;

[0066] The chain growth reaction occurring inside the quantum dot luminescent layer is as follows:

[0067]

[0068] In one possible implementation, the carrier functional layer is made of an inorganic metal oxide, the surface of which has hydroxyl groups.

[0069] In one possible implementation, the first electrode is a cathode, the second electrode is an anode, the charge carrier functional layer is an electron transport layer, and the material of the electron transport layer is zinc oxide;

[0070] Alternatively, the first electrode is the anode, the second electrode is the cathode, the carrier functional layer is the hole transport layer, and the material of the hole transport layer is nickel oxide.

[0071] This disclosure also provides a display panel, which includes the light-emitting diode device as described in this disclosure.

[0072] This disclosure also provides a display device, which includes the display panel as described in this disclosure.

[0073] This disclosure also provides a method for manufacturing a light-emitting diode (LED) device, comprising:

[0074] A quantum dot film layer comprising a first reactant is formed on a carrier substrate. The first reactant comprises a quantum dot body, a ligand molecule A connected to the quantum dot body, and a ligand molecule B connected to the quantum dot body.

[0075] By contacting the quantum dot film with the intermediate substrate, the ligand molecule B in the first reactant forms hydrogen bonds with the intermediate substrate, thereby adhering the quantum dot film.

[0076] The transfer substrate having the quantum dot film layer is bonded to a substrate having modified molecules, so that the ligand molecule A of the first reactant on the surface of the quantum dot film layer undergoes an atom transfer radical polymerization reaction with the modified molecules, and a continuous atom transfer radical polymerization reaction occurs inside the quantum dot film layer to form a quantum dot light-emitting layer. The substrate has a first electrode and a charge carrier functional layer located on the side of the first electrode away from the substrate. The modified molecules are connected to the surface of the charge carrier functional layer away from the first electrode.

[0077] Remove the intermediate substrate;

[0078] A second electrode is formed.

[0079] In one possible implementation, forming a quantum dot film layer comprising the first reactant on a carrier substrate includes:

[0080] An initial quantum dot film with initial ligands is formed on a carrier substrate;

[0081] A solution containing ligand molecule A and ligand molecule B is formed on the carrier substrate on which the initial quantum dot film is formed, so that ligand molecule A and ligand molecule B undergo ligand exchange reaction with the initial ligand.

[0082] In one possible implementation, forming an initial quantum dot film layer having initial ligands on a carrier substrate includes:

[0083] Silicon-based substrates are treated with octadecyltrimethoxysilane;

[0084] An initial quantum dot film with oleic acid ligands is formed on the silicon substrate.

[0085] In one possible implementation, the fabrication method further includes, before bonding the transfer substrate having the quantum dot film layer to the substrate having a carrier functional layer with modified molecules formed thereon:

[0086] Provide a substrate;

[0087] A carrier functional layer is formed on one side of the substrate.

[0088] A solution containing the modified molecules is formed on the surface of the charge carrier functional layer so that the modified molecules are coupled to the hydroxyl groups on the surface of the charge carrier functional layer.

[0089] In one possible implementation, after the quantum dot film layer is bonded together, and before the transfer substrate having the quantum dot film layer is bonded to the substrate substrate having the modified molecules formed thereon, the fabrication method further includes:

[0090] The transfer substrate with the quantum dot film attached is brought into contact with a grooved plate to form a patterned quantum dot film.

[0091] In one possible implementation, when bonding the transfer substrate having the quantum dot film layer to a substrate substrate having modified molecules, the fabrication method further includes:

[0092] Soaked in anisole solution of cuprous chloride.

[0093] In one possible implementation, the contact between the quantum dot film layer and the intermediate substrate includes:

[0094] The quantum dot film is brought into contact with a substrate made of polydimethylsiloxane. Attached Figure Description

[0095] Figure 1 This is a schematic diagram of the structure of a light-emitting diode device provided in an embodiment of the present disclosure;

[0096] Figure 2 A schematic diagram showing the binding of ligands in a quantum dot film layer to a modified molecule C on a substrate, as provided in an embodiment of this disclosure.

[0097] Figure 3 A schematic diagram illustrating the fabrication process of a light-emitting diode device provided in an embodiment of this disclosure;

[0098] Figure 4 A schematic diagram illustrating the fabrication process of a light-emitting diode device provided in an embodiment of this disclosure;

[0099] Figure 5 A schematic diagram illustrating the fabrication process of a specific light-emitting diode device provided in this embodiment of the disclosure;

[0100] Figure 6 A schematic diagram illustrating the fabrication process of a light-emitting diode device with a patterned quantum dot film layer provided in this embodiment of the disclosure;

[0101] Figure 7 This is a schematic diagram of a specific quantum dot film transfer process provided in an embodiment of the present disclosure. Detailed Implementation

[0102] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0103] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” 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.

[0104] To keep the following description of the embodiments of this disclosure clear and concise, detailed descriptions of known functions and known components are omitted.

[0105] See Figure 1 This disclosure provides a light-emitting diode device, comprising:

[0106] Substrate 1;

[0107] The first electrode 2 is located on one side of the substrate 1. Specifically, the first electrode 2 can be multiple structures spaced apart from each other.

[0108] The carrier functional layer 3 is located on the side of the first electrode 2 facing away from the substrate 1. Specifically, the carrier functional layer 3 can be multiple structures spaced apart from each other and corresponding one-to-one with the first electrode 2. The orthogonal projection of the first electrode 2 onto the substrate 1 can cover the orthogonal projection of the corresponding carrier functional layer 3 onto the substrate. Specifically, the light-emitting diode device can also have a barrier 7, which is used to separate sub-light-emitting devices 80 with different light-emitting colors (such as...). Figure 1 As shown, it may include two sub-light-emitting devices 80, one located on the left and one on the right. Each sub-light-emitting device 80 includes a first electrode 2, a carrier functional layer 3, a quantum dot light-emitting layer 4, and a second electrode 5. Of course, Figure 1This is merely an example illustrating that a light-emitting diode device has two sub-light-emitting devices 80. In actual implementation, a light-emitting diode device may have more sub-light-emitting devices 80, and the embodiments disclosed herein are not limited thereto.

[0109] The quantum dot luminescent layer 4 is located on the side of the charge carrier functional layer 3 opposite to the first electrode 2. The quantum dot luminescent layer 4 contains a molecular chain structure X, which is formed by an atom transfer radical polymerization (ATRP) reaction between the first reactant and the modifying molecule C. Figure 2 As shown, PDMS (polydimethylsiloxane) is used as the intermediate substrate when transferring the quantum dot light-emitting layer, ZnO is used as the material of the charge carrier functional layer 3, and ITO (indium tin oxide) is used as the material of the first electrode 2. The first reactant includes the quantum dot body QD and the ligand molecule A connected to the quantum dot body QD. The first reactant undergoes an atom transfer radical polymerization reaction with the modifying molecule C through the ligand molecule A. The modifying molecule C is initially connected to the side of the charge carrier functional layer 3 facing the quantum dot light-emitting layer 4. That is, before the atom transfer radical polymerization reaction is carried out, the side of the charge carrier functional layer 3 facing the quantum dot light-emitting layer can be first transferred. Modifying molecule C is formed on the surface of 4, while the quantum dot luminescent layer 3 is a film layer containing the first reactant. When the carrier functional layer 3 comes into contact with the quantum dot luminescent layer 4 by transferring the quantum dot luminescent layer, the ligand molecule A in the first reactant can undergo an atom transfer radical polymerization reaction with the modifying molecule C. Thus, the first reactant on the surface of the quantum dot luminescent layer 3 can first combine with the modifying molecule C. As the atom transfer radical polymerization reaction further occurs, the first reactant inside the quantum dot luminescent layer 3 also forms a molecular chain structure through the reaction, so that the entire quantum dot luminescent layer 3 forms an integral structure with molecular chain structures X bonded together. The quantum dot body can be a conventional quantum dot luminescent material.

[0110] The second electrode 5 is located on the side of the quantum dot light-emitting layer 4 opposite to the carrier functional layer 3. Specifically, the second electrode 5 can be a single, continuous layer. Of course, the second electrode 5 can also be a structure with electrodes spaced apart from each other.

[0111] The light-emitting diode device provided in this embodiment has a molecular chain structure X formed by the atom transfer radical polymerization reaction of a first reactant and a modifying molecule C in the quantum dot light-emitting layer 4. That is, the first surface 41 of the quantum dot light-emitting layer 4 facing the charge carrier functional layer 3, the second surface 42 of the quantum dot light-emitting layer 4 facing the second electrode 5, and the region between the first surface 41 and the second surface 42 all have molecular chain structures X. The entire quantum dot light-emitting layer 4 forms an integral structure in which molecular chain structures X are bonded together. When the quantum dot light-emitting layer 4 is transferred from the original carrier substrate to the substrate 1 of the light-emitting diode device by means of a transfer substrate, the quantum dot light-emitting layer 4 can be transferred as an integral structure from the transfer substrate to the substrate 1. This improves the problem in the prior art where the quantum dot light-emitting layer 4 only has the quantum dot body, and only a part of the quantum dot light-emitting layer on the surface of the transfer substrate can be transferred to the substrate, resulting in a low transfer yield of the light-emitting diode device.

[0112] In practical applications, ligand molecule A is characterized by containing styrene and its derivatives, acrylates and their derivatives, acrylamides and their derivatives, and acrylonitrile, etc. Specifically, the general formula of ligand molecule A is: Wherein, R1 is an electron-donating group, and R2 is a solubilizing group. In this embodiment, ligand molecule A is... R1 can provide electrons for the ATRP reaction, which is beneficial for the reaction to proceed. R2 can increase solubility, which is beneficial for the fabrication of ligand molecule A on the quantum dot (QD) substrate. Specifically, the structure of ligand molecule A, excluding R2, can contain styrene and its derivatives, acrylates and their derivatives, acrylamides and their derivatives, and acrylonitrile, etc.

[0113] Specifically, R1 can include one of the following: -S-.

[0114] Specifically, R2 includes one of the following: (CH2) n1 ; Where 1≤n1≤8, 1≤m1≤8.

[0115] In practical implementation, the general formula for modifying molecule C is: In this embodiment, R3 is a group that couples with the surface of the charge carrier functional layer, R6 is a halogenated group, and R5 is an electron-donating group. In this embodiment, the modified molecule C contains an R3 group at one end, which can couple with the surface of the charge carrier functional layer 3. Specifically, the surface of the charge carrier functional layer may have hydroxyl groups, and R3 can specifically be a group that can couple with hydroxyl groups. The R6 halogenated group and the R5 electron-donating group can enable an ATRP reaction with the ligand molecule A of the quantum dot luminescent layer 4.

[0116] Specifically, R3 includes one of the following:

[0117] Specifically, R6 includes one of the following: -Cl; -Br; -I.

[0118] Specifically, R5 includes one of the following: -O-; -S-.

[0119] Specifically, R4 includes one of the following: -(CH2) n2 - where 1≤n2≤12. R4 can give the modified molecule C a certain length, which can act as a solubilizer.

[0120] In practice, the first reactant includes ligand molecule B, whose general formula is:

[0121]

[0122] Wherein, 1≤n3≤12, 1≤m3≤12, R9 is a group that coordinates with the quantum dot body, and R11 is a group that forms a hydrogen bond with the intermediate substrate during the transfer of the quantum dot light-emitting layer. In this embodiment, the first reactant also includes ligand molecule B, which has group R9 that can coordinate with the quantum dot body, thereby enabling one end to be connected to the quantum dot body, and group R11 that forms a hydrogen bond with the intermediate substrate, thereby enabling bonding with the intermediate substrate and separating the quantum dot light-emitting layer from the original carrier substrate. It should be noted that the covalent bond bonding force between ligand molecule A of the quantum dot light-emitting layer and carrier functional layer 3 through the ATRP reaction is greater than the hydrogen bond bonding force between quantum dot light-emitting layer 4 and intermediate substrate through ligand molecule B, thereby enabling the transfer of quantum dot light-emitting layer 4 from intermediate substrate to substrate. In addition, the binding force of the quantum dot light-emitting layer 4 to the intermediate substrate through the hydrogen bond formed by the ligand molecule B is greater than the binding force between the quantum dot light-emitting layer 4 and the original carrier substrate, thereby enabling the transfer of the quantum dot light-emitting layer 4 from the carrier substrate to the intermediate substrate.

[0123] Specifically, R9 includes one of the following: -NH2; -SH; -COOH.

[0124] Specifically, R11 includes one of the following: -CHO; -OH; -COOH.

[0125] Specifically, R7 includes one of the following: -O-; -N-; -C-; -S-. In this embodiment of the disclosure, R1 can be an atom that connects the main chain and the side chain, serving a connecting function.

[0126] Specifically, R8 includes one of the following: -(CH2) a- where a = 1, 2, 3, or 4. In the embodiments of this disclosure, R8 is a branched chain, which can give the ligand molecule B a certain length and play a role in solubilization.

[0127] Specifically, R10 includes one of the following: -(CH2) b -; Wherein, 1≤b≤8, and c=1 or 2. In the embodiments of this disclosure, R10 alkane or aromatic group can act as a solubilizer.

[0128] In practical implementation, the structure of the quantum dot body connected to ligand molecule A can specifically be (i.e., the structure formed after the quantum dot body and ligand molecule A are connected): Specifically, the modification of molecule C can be:

[0129] The chain-initiated reaction occurring on the surface of the quantum dot luminescent layer 4 facing the carrier functional layer 3 is as follows:

[0130]

[0131] In this embodiment of the disclosure, the structure of the quantum dot body connected with ligand molecule A and the structure of the modifying molecule C can enable the quantum dot luminescent layer 4 and the charge carrier functional layer 3 to undergo the above-mentioned chain initiation reaction on the surface, and the following chain growth reaction to occur inside the quantum dot luminescent layer 4.

[0132] Specifically, the structure of the molecular chain is as follows: Where n4≥1;

[0133] The chain growth reaction occurring inside the quantum dot light-emitting layer is as follows:

[0134]

[0135] In practical implementation, the material of the charge carrier functional layer 3 can be an inorganic metal oxide. The surface of the inorganic metal oxide has hydroxyl groups, which allows the modified molecule C to be bound to the surface of the charge carrier functional layer 3.

[0136] In specific implementation, combined with Figure 1 As shown, the light-emitting diode device in this embodiment can be either an inverted structure or a normal structure. Specific examples are provided below:

[0137] For example, the light-emitting diode device has an inverted structure, with the first electrode 2 being the cathode, the second electrode 5 being the anode, and the carrier functional layer 3 being the electron transport layer, the material of which is zinc oxide;

[0138] For example, the light-emitting diode device has a positive structure, with the first electrode 2 being the anode, the second electrode 5 being the cathode, and the charge carrier functional layer 3 being the hole transport layer, the material of which is nickel oxide.

[0139] Based on the same inventive concept, embodiments of this disclosure also provide a display panel, which includes a light-emitting diode device as provided in embodiments of this disclosure.

[0140] In practical implementation, the display panel also includes thin-film transistors (TFTs), which are electrically connected to the sub-light-emitting device 80. The TFTs can be a-Si transistors, oxide transistors, or low-temperature polycrystalline silicon transistors. The TFTs can be top-gate TFTs or bottom-gate TFTs. Figure 3 As shown, the thin-film transistor includes a gate 141, an active layer 12, and a source-drain layer 18 (specifically, it may include a source 181 and a drain 182). The gate 141 may be located on the side of the active layer 12 facing away from the substrate 1, and the source-drain layer 18 is located on the side of the gate 141 facing away from the active layer 12, and is electrically connected to the sub-light-emitting device 80 through the drain 182. Furthermore, the display panel also includes a first storage capacitor electrode 142 and a second storage capacitor electrode 16. The first storage capacitor electrode 142 is disposed on the same layer as the gate 141, and the second storage capacitor electrode 16 is disposed separately between the gate 141 and the source-drain layer 18. Furthermore, multiple insulating layers may be disposed between the active layer 12 and the source / drain layer 18. For example, the multiple insulating layers include: a first insulating layer 13 disposed between the active layer 12 and the gate 141; a second insulating layer 15 disposed between the gate 141 and the second storage capacitor electrode 16; and an interlayer dielectric layer 17 disposed between the source / drain layer 18 and the second storage capacitor electrode 16. Furthermore, a passivation layer 191 may be disposed between the source / drain layer 18 and the first electrode 2, and a planarization layer 192 may be disposed between the passivation layer 191 and the first electrode 2. Furthermore, a buffer layer 11 may be disposed between the substrate 1 and the active layer 12.

[0141] When the light-emitting diode device is inverted, there is a hole transport layer 61 between the quantum dot light-emitting layer 4 and the second electrode 5, and a hole injection layer 62 between the hole transport layer 61 and the second electrode 5; when the light-emitting diode device is upright, there is an electron transport layer 61 between the quantum dot light-emitting layer 4 and the second electrode 5, and an electron injection layer 62 between the electron transport layer 61 and the second electrode 5.

[0142] Based on the same inventive concept, embodiments of this disclosure also provide a display device, which includes a display panel as provided in embodiments of this disclosure.

[0143] See Figure 4As shown in the embodiments of this disclosure, a method for manufacturing a light-emitting diode device is also provided, comprising:

[0144] Step S100: Form a quantum dot film layer including a first reactant on a carrier substrate. The first reactant includes a quantum dot body, a ligand molecule A connected to the quantum dot body, and a ligand molecule B connected to the quantum dot body.

[0145] Specifically, the first reactant can be formed through a ligand exchange reaction, that is, step S100 can include steps S101 and S102, as follows:

[0146] Step S101: Forming an initial quantum dot film layer with initial ligands on a carrier substrate; specifically, in order to reduce the adhesion between the initial quantum dot film layer and the carrier substrate, the carrier substrate can be treated first to reduce the difficulty of transferring the initial quantum dot film layer to the intermediate substrate. That is, step S101 may specifically include: treating the silicon substrate with octadecanetrimethoxysilane; forming an initial quantum dot film layer with oleic acid ligands on the silicon substrate; wherein, oleic acid ligands can be used as initial ligands;

[0147] Step S102: A solution containing ligand molecule A and ligand molecule B is formed on a carrier substrate on which the initial quantum dot film layer is formed, so that ligand molecule A and ligand molecule B undergo a ligand exchange reaction with the initial ligand; the specific materials of ligand molecule A and ligand molecule B can be found in the specific materials given in the light-emitting diode device embodiment provided in the embodiment of the present invention.

[0148] Step S200: The quantum dot film is brought into contact with the intermediate substrate to form hydrogen bonds between the ligand molecule B in the first reactant and the intermediate substrate, thereby adhering the quantum dot film. In this step S200, the ligand molecule B can be pre-formed in the first reactant. When the intermediate substrate comes into contact with the quantum dot film on the carrier substrate containing the ligand molecule B, the ligand molecule B can form hydrogen bonds with the intermediate substrate. The force of the hydrogen bonds is greater than the initial bonding force between the quantum dot film and the carrier substrate, thereby enabling the quantum dot film to be adhered to the carrier substrate.

[0149] Step S300: The transfer substrate with a quantum dot film layer is bonded to the substrate with modified molecules, so that the ligand molecules A of the first reactant on the surface of the quantum dot film layer undergo an atom transfer radical polymerization reaction with the modified molecules, and a continuous atom transfer radical polymerization reaction occurs inside the quantum dot film layer to form a quantum dot light-emitting layer. The substrate has a first electrode and a charge carrier functional layer located on the side of the first electrode away from the substrate. The modified molecules are connected to the surface of the charge carrier functional layer away from the first electrode. In this step S300, in order to catalyze the ATRP reaction between the ligand molecules A and the modified molecules, when bonding the transfer substrate with the quantum dot film layer and the substrate with modified molecules, the bonded transfer substrate and substrate can be immersed in a cuprous chloride anisole solution.

[0150] Step S400: Remove the intermediate substrate. It should be noted that the ligand molecule B bound to the intermediate substrate can be removed along with the intermediate substrate when the intermediate substrate is removed. That is, in the final light-emitting diode device, the molecular chain structure in the quantum dot light-emitting film layer may not contain ligand molecule B. Ligand molecule B exists in the process of fabricating the light-emitting diode device, during the process of transferring the quantum dot film layer to the substrate. Of course, considering the actual process limitations, ligand molecule B may not be completely removed. Therefore, in the final light-emitting diode device, some ligand molecule B may remain.

[0151] Step S500: Form the second electrode.

[0152] The method for fabricating a light-emitting diode (LED) device provided in this disclosure first forms a quantum dot film layer with weak adhesion to a carrier substrate. Then, a transfer substrate is brought into contact with the quantum dot film layer to form hydrogen bonds between the quantum dot film layer and the transfer substrate, which are stronger than those between the quantum dot film layer and the carrier substrate. When the transfer substrate is removed, the quantum dot film layer can be transferred along with it. When the side of the transfer substrate with the quantum dot film layer is then bonded to a substrate, the ligand molecules A in the quantum dot film layer and the modification molecules C in the substrate can undergo an ATRP reaction. Because the covalent bonds formed by the ATRP reaction have a stronger bonding force than hydrogen bonds, the bonding force between the transfer substrate and the substrate can be increased. When separating the substrate, the quantum dot film can remain on the substrate, enabling the formation of the quantum dot film on the substrate through transfer. Moreover, compared to the existing transfer methods for quantum dot films, the fabrication method provided in this disclosure allows the first reactant of the quantum dot film to undergo an ATRP reaction with the modification molecules of the substrate at the interface between the quantum dot film and the charge carrier functional layer, as well as within the quantum dot film. This results in the quantum dot film forming a tightly bonded whole, which can be transferred together from the intermediate substrate to the substrate, achieving a high transfer yield of the quantum dot film and avoiding the problem of only a portion of the quantum dot film being transferred from the intermediate substrate to the substrate.

[0153] In specific implementation, combined with Figure 5 As shown, before bonding the transfer substrate with the quantum dot film layer to the substrate with the carrier functional layer formed with modified molecules, the fabrication method further includes:

[0154] Step S600: Provide a substrate.

[0155] Step S700: Form a carrier functional layer on one side of the substrate.

[0156] Step S800: A solution containing modified molecules is formed on the surface of the charge carrier functional layer so that the modified molecules are coupled to the hydroxyl groups on the surface of the charge carrier functional layer.

[0157] For specific implementation, see Figure 6 As shown, in order to form a patterned quantum dot film, the fabrication method may further include the following steps after step S200 and before step S300, that is, after the quantum dot film is bonded and before the transfer substrate having the quantum dot film is bonded to the substrate having the modified molecules:

[0158] Step S900: The transfer substrate with the quantum dot film layer bonded to it is brought into contact with the grooved gravure plate to form a patterned quantum dot film layer. Figure 7 As shown, after the transfer substrate comes into contact with the grooved engraving, a quantum dot film layer with raised sections corresponding to the grooves can be formed on the transfer substrate (i.e., quantum dots outside the grooved area remain on the engraving; after contact with the engraving, the transfer substrate only has a quantum dot film layer at the grooved sections). When transferring the raised quantum dot film layer to the display substrate, the raised quantum dot film layer can be aligned with the recessed area of ​​the display substrate where the light-emitting device is located, thus forming a patterned quantum dot film layer within the light-emitting device area defined by the baffle 7. Of course, it should be noted that... Figure 7This is merely a schematic illustration of the transfer using the grooves of the intaglio printing plate as a ring. In actual implementation, the shape of the grooves of the intaglio printing plate can be consistent with the pattern of the area where the light-emitting device of the display substrate is located. The above describes a method for forming patterned quantum dots using a grooved gravure plate. Before contacting the gravure plate, the transfer substrate is a single, flat layer. In practice, a patterned transfer substrate (i.e., a transfer substrate with both raised and recessed portions) can be formed. When the transfer substrate contacts the carrier substrate of the original substrate, the portions that can contact the quantum dot film on the carrier substrate (i.e., the raised portions of the transfer substrate) will adsorb the quantum dot film due to hydrogen bonds formed between the transfer substrate and the quantum dot film. The portions that do not contact the quantum dot film (i.e., the recessed portions of the transfer substrate) will not adsorb the quantum dot film, thus forming a patterned quantum dot film on the transfer substrate. Afterward, the transfer substrate can be directly contacted with the display substrate to transfer the patterned quantum dot film onto the display substrate. In this transfer method, the pattern on the transfer substrate can be consistent with the pattern of the area containing the light-emitting device on the display substrate.

[0159] In specific implementation, the material of the transfer substrate can be polydimethylsiloxane (PDMS). For step S200, the contact between the transfer substrate and the quantum dot film layer can specifically include: contacting the quantum dot film layer through a substrate made of polydimethylsiloxane. The transfer substrate, being made of PDMS, can form hydrogen bonds with ligand molecules B in the quantum dot film layer.

[0160] To better understand the fabrication method of the light-emitting diode device provided in the embodiments of this disclosure, combined with... Figure 7 As shown, the following example uses a light-emitting diode (LED) device with an inverted structure for specific illustration:

[0161] Preparation of patterned quantum dot film: A quantum dot solution of 15 mg / ml was spin-coated onto a silicon substrate (carrier substrate) treated with octadecyltrimethoxysilane (2500 rpm / s). After spin-coating, a methanol solution of ligand A and ligand B (20 mg / ml) was dropped onto the quantum dot film for ligand exchange. After standing for 30 seconds, the methanol was removed by spin-coating. Excess ligands on the surface of the quantum dot film were cleaned twice with methanol, and then annealed at 120°C for 20 minutes. The quantum dot film was quickly picked up using a PDMS substrate (transfer substrate) and brought into contact with the grooves of a gravure printing plate to form a patterned quantum dot film.

[0162] A 15 mg / ml solution of zinc oxide (as the subsequent carrier functional layer) nanoparticles was first spin-coated onto an ITO substrate (substrate) at 4000 rpm / s and annealed at 120°C for 20 minutes. A modified molecular C ethanol solution was placed on the zinc oxide film for 5 minutes, then excess solvent was removed by spin-coating, and the film was annealed at 100°C for 10 minutes to accelerate the coupling between the silane reagent and the hydroxyl groups on the zinc oxide surface. A patterned quantum dot film layer on a PDMS substrate (intermediate substrate) was then brought into contact with the zinc oxide film surface and immersed in an anisole solution containing cuprous chloride. An ATRP reaction was performed at 80°C in an anhydrous and oxygen-free nitrogen atmosphere. After the reaction, impurities were removed by washing with anisole, and the film was annealed at 120°C for 20 minutes. Next, a hole transport layer material and a silver electrode (second electrode) were deposited on top of the quantum dot film to fabricate a patterned quantum dot light-emitting diode device.

[0163] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0164] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations to the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A light-emitting diode device, wherein, include: Substrate; The first electrode is located on one side of the substrate. A charge carrier functional layer is located on the side of the first electrode opposite to the substrate. A quantum dot luminescent layer is located on the side of the charge carrier functional layer opposite to the first electrode. The quantum dot luminescent layer has a molecular chain structure, wherein the molecular chain structure is formed by an atom transfer radical polymerization reaction between a first reactant and a modifying molecule. The first reactant includes a quantum dot body and a ligand molecule A connected to the quantum dot body. The first reactant undergoes an atom transfer radical polymerization reaction with the modifying molecule through the ligand molecule A. The modifying molecule is initially connected to the side of the charge carrier functional layer facing the quantum dot luminescent layer. The second electrode is located on the side of the quantum dot light-emitting layer opposite to the carrier functional layer.

2. The light-emitting diode device as described in claim 1, wherein, The general formula of the ligand molecule A is: In this group, R1 is an electron-donating group and R2 is a solubilizing group.

3. The light-emitting diode device as described in claim 2, wherein, R1 includes one of the following: -S-。 4. The light-emitting diode device as described in claim 3, wherein, R2 includes one of the following: -(CH2)n1-; Where 1≤n1≤8, 1≤m1≤8.

5. The light-emitting diode device as described in claim 1, wherein, The general formula of the modified molecule is: Wherein, R3 is a group that couples with the surface of the carrier functional layer, R6 is a halogenated group, and R5 is an electron-donating group.

6. The light-emitting diode device as described in claim 5, wherein, R3 includes one of the following:

7. The light-emitting diode device as described in claim 5, wherein, R6 includes one of the following: -Cl； -Br； -I。 8. The light-emitting diode device as described in claim 5, wherein, R5 includes one of the following: -O-； -S-。 9. The light-emitting diode device as described in claim 5, wherein, R4 includes one of the following: -(CH2) n2 - where 1≤n2≤12.

10. The light-emitting diode device as claimed in claim 1, wherein, The first reactant includes ligand molecule B, the general formula of which is: Wherein, 1≤n3≤12, 1≤m3≤12, R9 is a group that coordinates with the quantum dot body, and R11 is a group that forms hydrogen bonds with the intermediate substrate when the quantum dot light-emitting layer is transferred.

11. The light-emitting diode device as claimed in claim 10, wherein, R9 includes one of the following: -NH2; -SH; -COOH.

12. The light-emitting diode device as claimed in claim 10, wherein, R11 includes one of the following: -CHO; -OH; -COOH.

13. The light-emitting diode device as claimed in claim 10, wherein, R7 includes one of the following: -O-； -N-； -C-； -S-。 14. The light-emitting diode device as claimed in claim 10, wherein, R8 includes one of the following: -(CH2) a - where a = 1, 2, 3 or 4.

15. The light-emitting diode device as claimed in claim 10, wherein, R10 includes one of the following: -(CH2) b -; Where 1≤b≤8, c=1 or 2.

16. The light-emitting diode device as claimed in claim 5, wherein, The structure of the quantum dot body connected to the ligand molecule A is as follows: The modified molecule is: The chain initiation reaction occurring on the surface of the quantum dot luminescent layer facing the charge carrier functional layer is as follows:

17. The light-emitting diode device as claimed in claim 16, wherein, The molecular chain structure is as follows: Where n4≥1; The chain growth reaction occurring inside the quantum dot luminescent layer is as follows:

18. The light-emitting diode device as claimed in claim 1, wherein, The carrier functional layer is made of inorganic metal oxide, and the surface of the inorganic metal oxide has hydroxyl groups.

19. The light-emitting diode device as claimed in claim 18, wherein, The first electrode is a cathode, the second electrode is an anode, the charge carrier functional layer is an electron transport layer, and the material of the electron transport layer is zinc oxide; Alternatively, the first electrode is the anode, the second electrode is the cathode, the carrier functional layer is the hole transport layer, and the material of the hole transport layer is nickel oxide.

20. A display panel, wherein, Includes the light-emitting diode device as described in any one of claims 1-19.

21. A display device, wherein, Includes the display panel as described in claim 20.

22. A method for fabricating a light-emitting diode (LED) device, wherein, include: A quantum dot film layer comprising a first reactant is formed on a carrier substrate. The first reactant comprises a quantum dot body, a ligand molecule A connected to the quantum dot body, and a ligand molecule B connected to the quantum dot body. By contacting the quantum dot film with the intermediate substrate, the ligand molecule B in the first reactant forms hydrogen bonds with the intermediate substrate, thereby adhering the quantum dot film. The transfer substrate having the quantum dot film layer is bonded to a substrate having modified molecules, so that the ligand molecule A of the first reactant on the surface of the quantum dot film layer undergoes an atom transfer radical polymerization reaction with the modified molecules, and a continuous atom transfer radical polymerization reaction occurs inside the quantum dot film layer to form a quantum dot light-emitting layer. The substrate has a first electrode and a charge carrier functional layer located on the side of the first electrode away from the substrate. The modified molecules are connected to the surface of the charge carrier functional layer away from the first electrode. Remove the intermediate substrate; A second electrode is formed.

23. The manufacturing method as described in claim 22, wherein, The formation of a quantum dot film layer comprising a first reactant on a carrier substrate includes: An initial quantum dot film with initial ligands is formed on a carrier substrate; A solution containing ligand molecule A and ligand molecule B is formed on the carrier substrate on which the initial quantum dot film is formed, so that ligand molecule A and ligand molecule B undergo ligand exchange reaction with the initial ligand.

24. The manufacturing method as described in claim 23, wherein, The formation of an initial quantum dot film layer with initial ligands on a carrier substrate includes: Silicon-based substrates are treated with octadecyltrimethoxysilane; An initial quantum dot film with oleic acid ligands is formed on the silicon substrate.

25. The manufacturing method as described in claim 22, wherein, Before bonding the transfer substrate with the quantum dot film layer to the substrate with the carrier functional layer formed with modified molecules, the fabrication method further includes: Provide a substrate; A carrier functional layer is formed on one side of the substrate. A solution containing the modified molecules is formed on the surface of the charge carrier functional layer so that the modified molecules are coupled to the hydroxyl groups on the surface of the charge carrier functional layer.

26. The manufacturing method as described in claim 25, wherein, After the quantum dot film layer is bonded together, and before the transfer substrate having the quantum dot film layer is bonded to the substrate substrate having the modified molecules formed thereon, the fabrication method further includes: The transfer substrate with the quantum dot film attached is brought into contact with a grooved plate to form a patterned quantum dot film.

27. The manufacturing method as described in claim 22, wherein, When bonding the transfer substrate having the quantum dot film layer to the substrate substrate having the modified molecules, the fabrication method further includes: immersing it in anisole solution of cuprous chloride.

28. The manufacturing method as described in claim 22, wherein, The contact between the quantum dot film layer and the intermediate substrate includes: The quantum dot film is brought into contact with a substrate made of polydimethylsiloxane.

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