Cloud-based medical device approval support platform and how it works

Abstract

A zinc oxide nanoparticle ink composition containing a polyfunctional acrylic monomer as a ligand and a method for manufacturing the same are proposed, which can simplify the process and drastically reduce process time and lower manufacturing costs by enabling the process to be performed in one step through the high concentration of the zinc oxide nanoparticle ink composition. The method for manufacturing the zinc oxide nanoparticle ink composition comprises the steps of: mixing zinc oxide nanoparticles with a ligand containing at least three acrylate functional groups to attach the ligand to the surface of the zinc oxide nanoparticles; and mixing the zinc oxide nanoparticles with the attached ligand with a solvent.

Description

Technology Field

[0001] The present invention relates to a zinc oxide nanoparticle ink composition comprising a polyfunctional acrylic monomer as a ligand and a method for manufacturing the same. More specifically, the invention relates to a zinc oxide nanoparticle ink composition comprising a polyfunctional acrylic monomer as a ligand and a method for manufacturing the same, wherein the process can be performed in a single step by increasing the concentration of the zinc oxide nanoparticle ink composition, thereby simplifying the process and drastically reducing the process time to lower manufacturing costs. Background Technology

[0002] Electroluminescence devices are devices that utilize the phenomenon of emitting light when an electric field is applied to a material. In this device, electrons and holes injected into the light-emitting layer form excitons and then emit light through recombination. Recently, many devices using quantum dots as the light-emitting layer have been developed.

[0003] Quantum dots are nanoscale semiconductor materials that exhibit quantum confinement effects. When these quantum dots receive light from an excitation source and reach an excited energy state, they emit energy as light according to their energy band gap. Therefore, since electrical and optical properties can be controlled by adjusting the size of the quantum dots, they are being applied in various devices such as photodetectors and light-emitting devices.

[0004] Devices using quantum dots as a light source have a layer that transports electrons or holes in the quantum dot light-emitting layer. At this time, if the electrons and holes injected into the quantum dot light-emitting layer are in balance, the luminous efficiency of the quantum dot light-emitting device is maximized; however, if they are not in balance, non-radiative transitions due to Auger recombination occur, resulting in reduced efficiency. Therefore, various technologies are being developed to increase the luminous efficiency of quantum dot light-emitting devices.

[0005] Zinc oxide nanoparticles are attracting attention as electron transport layers in indium phosphide-based quantum dot light-emitting diode devices due to their excellent efficiency characteristics. Zinc oxide nanoparticles are synthesized by the sol-gel method and, after synthesis, exhibit hydrophilic properties, allowing them to be immediately dispersed in hydrophilic solvents such as alcohols. Consequently, they possess solvent orthogonality with hydrophobic quantum dot thin films, enabling the formation of quantum dot light-emitting diode devices. The problem to be solved

[0006] The present invention aims to solve the above-mentioned problems, and the objective of the present invention is to provide a zinc oxide nanoparticle ink composition containing a polyfunctional acrylic monomer as a ligand and a method for manufacturing the same, which can simplify the process and drastically reduce the process time and lower manufacturing costs by enabling the process to be performed in one step through the high concentration of the zinc oxide nanoparticle ink composition. means of solving the problem

[0007] A method for preparing a zinc oxide nanoparticle ink composition according to one embodiment of the present invention for achieving the above objective comprises: a step of attaching a ligand to the surface of zinc oxide nanoparticles by mixing zinc oxide nanoparticles and a ligand comprising at least three acrylate functional groups; and a step of mixing the zinc oxide nanoparticles with the attached ligand and a solvent.

[0008] The ligand may be at least one of dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and pentaerythritol triacrylate.

[0009] The ligand may further include at least one of a hydroxyl functional group, an amine functional group, a carboxyl functional group, and a thiol functional group.

[0010] Zinc oxide nanoparticles may include at least one of an acetate functional group, an ethanolamine functional group, and a chloride functional group. Effects of the invention

[0011] According to embodiments of the present invention, when forming an electron transport layer using an inkjet method, a high-concentration zinc oxide nanoparticle ink composition that can be jetted without clumping can be obtained, so the process can be performed in one step, which simplifies the process and drastically reduces the process time, thereby having the effect of lowering manufacturing costs.

[0012] In addition, a quantum dot light-emitting diode comprising an electron transport layer using a zinc oxide ink composition prepared according to the present invention can suppress electron injection into the quantum dot light-emitting layer due to the polyfunctional acrylic monomer ligands included in the zinc oxide nanoparticles, thereby controlling the balance between the electron injection ratio and the hole injection ratio, which has the effect of improving the brightness efficiency and external quantum efficiency of the quantum dot light-emitting diode. Specific details for implementing the invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. However, embodiments of the present invention may be modified in various different forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Although components may be depicted in the attached drawings having a specific pattern or a predetermined thickness, this is for convenience of explanation or distinction, and therefore, even if a specific pattern and a predetermined thickness are depicted, the present invention is not limited only to the features of the depicted components.

[0014] A method for preparing a zinc oxide nanoparticle ink composition according to one embodiment of the present invention comprises the steps of: mixing zinc oxide nanoparticles and a ligand comprising at least three acrylate functional groups to attach the ligand to the surface of the zinc oxide nanoparticles; and mixing the zinc oxide nanoparticles with the attached ligand and a solvent.

[0015] Zinc oxide nanoparticles prepared according to the present invention can be used in an electron transport layer for transporting electrons to the light-emitting layer of a quantum dot light-emitting diode. A quantum dot light-emitting diode comprises a light-emitting layer containing quantum dots, electron transport layers and hole transport layers on both sides of the light-emitting layer, and an anode and a cathode at the outermost edge, respectively. When electrons and holes injected into the quantum dot light-emitting layer are balanced, the luminous efficiency of the quantum dot light-emitting device is maximized, but if they are not balanced, non-radiative transitions due to Auger recombination occur, resulting in lower efficiency.

[0016] Figure 1 is an image showing zinc oxide nanoparticle ink being injected into pixel areas separated by partitions to manufacture a display using multiple quantum dot light-emitting diodes, Figure 2 is an image after the zinc oxide nanoparticle ink has been injected, and Figure 3 is a graph showing the concentration of the zinc oxide nanoparticle ink composition according to pixel size.

[0017] In Fig. 1, an ink composition containing zinc oxide nanoparticles is extruded through a 3 μm-sized barrier to form an electron transport layer thin film. The process may vary depending on the concentration of zinc oxide nanoparticles in the ink composition during thin film formation. In Fig. 2, the coffee ring is not visible in the image of the zinc oxide nanoparticle thin film after injection.

[0018] Zinc oxide nanoparticles prepared by the sol-gel method can exhibit a maximum concentration of 30 to 60 mg / ml in the solvent. In the process for forming a thin film using a zinc oxide nanoparticle ink composition, a drying step is performed after ink jetting; however, if the concentration of zinc oxide nanoparticles in the ink composition is low, the ink jetting and drying steps must be repeated. In other words, to form a zinc oxide nanoparticle thin film layer with a thickness of tens of nanometers, there are multiple process steps, and the process time increases accordingly, which may increase the device manufacturing cost.

[0019] If the jetting volume is increased to reduce the process steps, ink may overflow to adjacent pixels, causing defects. Therefore, the concentration of zinc oxide nanoparticles must be increased to reduce the process steps.

[0020] Figure 3 is a graph showing the zinc oxide nanoparticle ink concentration for each pixel size required to form a zinc oxide nanoparticle film of 30 nm, assuming a droplet volume of 36 pl. That is, for a square pixel of size 60 µm x 60 µm, the concentration of zinc oxide nanoparticle ink is at least 20 mg / ml.

Claims

Claim 1 A method for preparing a zinc oxide nanoparticle ink composition comprising: a step of attaching a ligand to the surface of zinc oxide nanoparticles by mixing zinc oxide nanoparticles and a ligand comprising at least three acrylate functional groups; and a step of mixing the zinc oxide nanoparticles with the attached ligand and a solvent.

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