CN111983830A

CN111983830A - Equipment and preparation method of quantum dot film

Info

Publication number: CN111983830A
Application number: CN202010787188.4A
Authority: CN
Inventors: 陈黎暄
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2020-11-24

Abstract

The application discloses equipment and quantum dot film's preparation method, equipment is used for preparing quantum dot film, include: a container for loading the quantum dot solution; the lifting device is arranged above the container; a gripping device mounted to the lifting device and facing a side of the container; and a controller connected to the lifting device and the clamping device. This application is through the mode preparation quantum dot membrane of soaking formula, and this mode is favorable to forming a film on the base plate of great size, and has overcome because of the concentration restriction of quantum dot solution and the difficult problem that disperses to guarantee the homogeneity of the quantum dot membrane of forming a film, thick homogeneity of membrane and the balance of dispersed concentration.

Description

Equipment and preparation method of quantum dot film

Technical Field

The application relates to the technical field of display, in particular to a device and a preparation method of a quantum dot film.

Background

With the development of science and technology and the progress of society, people increasingly depend on information exchange, transmission and the like. The display device, as a main carrier and material basis for information exchange and transmission, has become a hot spot and a high place for many scientists engaged in information photoelectric research to compete.

Quantum Dots (QD) are extremely small inorganic nanocrystals that are invisible to the naked eye. The quantum dots can emit colored light when being stimulated by light or electricity, the color of the light is determined by the composition material and the size and shape of the quantum dots, and generally, the smaller the particle of the quantum dots is, the longer the wavelength of the light can be absorbed; the larger the particle of the quantum dot, the shorter the wavelength it absorbs. The quantum dots can absorb blue of short wave and excite to present long-wave-band light color. This property enables the quantum dots to change the color of light emitted by the light source.

The quantum dot display technology has been comprehensively upgraded in various dimensions such as color gamut coverage, color control accuracy, red, green and blue color purity and the like, is considered as an improvement point of the global display technology, and is also considered as a display technology revolution affecting the world. The full-color-domain display is realized in a revolutionary way, and the color of the image is restored most truly. Enterprises such as samsung, LG, apple and the like are actively promoting the research and development of quantum dot display technology, and enterprises such as amazon, large wonder and the like adopt the quantum dot technology to improve the image quality of products to different degrees. With the prior release of quantum dot televisions by TCL, international quantum dot display arrays have been on the initial scale.

Semiconductor nanocrystals with quantum dots with radii less than or close to the Bohr radius, three dimensional nanomaterials composed mostly of elements of groups II-VI or III-V. Due to quantum confinement effects, the transport of electrons and holes inside is restricted, so that the continuous energy band structure becomes a separated energy level structure. When the quantum dots are different in size, the quantum confinement degree of electrons and holes is different, and the discrete energy level structures are different. After being excited by external energy, the quantum dots with different sizes emit light with different wavelengths, namely light with various colors.

The quantum dots have the advantages that: by regulating the size of the quantum dots, the light-emitting wavelength range can cover infrared and the whole visible light wave band, the light-emitting wave band is narrow, and the color saturation is high; the quantum dot material has high quantum conversion efficiency; the material performance is stable; the preparation method is simple and various, can be prepared from the solution, and has rich resources.

In recent years, organic-inorganic hybrid perovskites (CH) have been developed due to their low cost, high carrier mobility, large light absorption coefficient, and the like₃NH₃PbX₃X ═ Cl, Br, I) materialsHas excellent performance in the field of solar cells. However, the fluorescence quantum efficiency of organic-inorganic hybrid perovskite thin films is generally low due to the presence of a large number of intrinsic defects (<20%), which limits their use in the fields of electroluminescence, lasers, displays, etc. Recent studies have shown that, with the reduction of the size of perovskite, the number of internal defects can be effectively reduced, non-radiative transitions can be reduced, and the fluorescence efficiency can be improved. However, the problem of poor stability has been restricting the development of organic-inorganic hybrid perovskite quantum dots.

Meanwhile, the perovskite phase organic metal halide is also one of potential quantum dot application materials, but is not easy to disperse in a solution phase, and a certain difficulty exists in film formation. The traditional Cd (cadmium) quantum dot material or ln (lanthanum) quantum dot material is subjected to spin coating film formation in solution phase, and the balance problems of film formation uniformity, film thickness and dispersion concentration also exist, the higher concentration is difficult to form a film layer with uniform travel, and the higher quantum dot concentration is the key for improving photoluminescence specific gravity and further displaying the color gamut.

Disclosure of Invention

The invention aims to provide equipment and a preparation method of a quantum dot film, and aims to solve the technical problems that the existing organic-inorganic hybrid perovskite quantum dot is poor in stability, poor in uniformity, uneven in film thickness and unbalanced in dispersion concentration in a film forming process.

To achieve the above object, the present invention provides an apparatus for preparing a quantum dot film, comprising: a container for loading the quantum dot solution; the lifting device is arranged above the container; a gripping device mounted to the lifting device and facing a side of the container; and a controller connected to the lifting device and the clamping device.

Further, the clamping device includes: at least one pair of clamps; and at least one pair of blowing devices respectively connected to the clamps.

Further, the equipment also comprises an angle adjuster which is connected between the clamp and the lifting device; when the clamp clamps the substrate, the angle regulator can regulate the angle of the substrate, so that the included angle formed by the substrate and the horizontal plane of the quantum dot solution is greater than 5 degrees and smaller than 90 degrees.

Furthermore, the material of the container is one of glass, ceramic and metal.

In order to achieve the above object, the present invention also provides a method for preparing a quantum dot film, comprising the steps of:

providing a substrate and the apparatus described above;

controlling a clamping device to clamp the substrate;

controlling a lifting device to soak the unclamped part of the substrate in a quantum dot solution, wherein the part of the substrate soaked by the quantum dot solution is an effective area, and the part of the substrate not soaked by the quantum dot solution is an ineffective area;

controlling a lifting device to perform uniform-speed upward pulling treatment on the substrate, and forming undried quantum dot films on the surfaces of the two sides of the effective area of the substrate; and

and placing the substrate on a carrying table, and baking the substrate, wherein the two side surfaces of the active area of the substrate form a solidified quantum dot film.

Further, in the step of clamping the substrate, the clamping device is provided with at least one pair of clamps and at least one pair of air blowing devices, and the at least one pair of air blowing devices are respectively arranged on the opposite surfaces of the clamps; wherein, the air blowing device is utilized to form air pressure on two sides of the substrate so as to clamp the substrate.

Further, the invalid region is located at one side of the substrate, and the invalid region and the active region have a boundary line; in the step of clamping the substrate, the clamp clamps the inactive area when clamping the substrate.

Further, the inactive area has a width less than 50cm, and the distance between the jig and the boundary line is greater than 50um when the jig is clamped.

Further, in the step of pulling up the substrate, the uniform pulling-up speed of the substrate is 0.1um/s to 10 cm/s.

Further, between the substrate soaking step and the substrate pulling-up step, the method further comprises the following steps:

controlling an angle adjuster to adjust the angle of a substrate, and performing inclination processing on the substrate; so that the included angle formed by the substrate and the horizontal plane of the quantum dot solution is more than 5 degrees and less than 90 degrees.

The invention has the technical effects that in the process of preparing the quantum dot film, the quantum dot film is prepared in a soaking mode, the mode is favorable for forming the film on a substrate with larger size, and the problems of concentration limitation and difficult dispersion of a quantum dot solution are solved, so that the uniformity, the uniform film thickness and the balance of dispersion concentration of the formed quantum dot film are ensured.

Drawings

The technical solution and other advantages of the present application will become apparent from the detailed description of the embodiments of the present application with reference to the accompanying drawings.

Fig. 1 is a flowchart of a method for manufacturing a quantum dot film according to an embodiment of the present disclosure.

Fig. 2 is a front view of a quantum dot device according to an embodiment of the present application.

Fig. 3 is a rear view of a quantum dot device according to an embodiment of the present application.

Fig. 4 is a side view of a quantum dot device according to an embodiment of the present application.

Fig. 5 is a schematic structural diagram of the substrate clamped by the clamp according to the embodiment of the present application.

Fig. 6 is a schematic structural view of the quantum dot film covering two sides of the substrate according to the embodiment of the present application.

The components of the drawings are identified as follows:

1, container; 2, a lifting device;

3, a clamping device; 4, a controller;

5, a blowing device;

11 an effective area; 12 an invalid region;

10 a substrate; 20 quantum dot films;

a 30 stage; 31 a clamp;

121 a clamping area; 122 boundary region

A 32-degree adjuster; 311 a first clamp;

312 second clamp.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

As shown in fig. 1, this embodiment provides a method for preparing a quantum dot film, including the following steps S1) -S6).

S1) providing a substrate and an apparatus. The substrate is preferably an organic film layer, and the quantum dot solution can be formed into a film on the surface of the substrate.

S2) controlling the clamping device to clamp the substrate. In step S2), providing a clamping device having at least one pair of clamps; and clamping the substrate by using the air pressure difference between the inside and the outside of the clamp.

Specifically, as shown in fig. 2 to 4, in the process of preparing the quantum dot film, a quantum dot device is provided, which includes a holding device 3 including a first holder 311 and a second holder 312. In this embodiment, the first clamp 311 and the second clamp 312 are respectively connected to two air blowing devices 5 through a pipe, the air blowing devices are air cylinders, then the two air blowing devices 5 are driven to form an air pressure difference between the inside and the outside of the first clamp 311 and the second clamp 312, and the substrate 10 is clamped between the clamps 3 by the air pressure difference, so that the substrate cannot slip off due to gravity.

S3) controlling a lifting device to soak the part of the substrate which is not clamped in a quantum dot solution, wherein the part of the substrate soaked in the quantum dot solution is an effective area, and the part of the substrate not soaked in the quantum dot solution is an ineffective area. The inactive area has a width less than 50cm, and the distance between the jig and the boundary is greater than 50um when the jig is clamped.

As shown in fig. 2-4, the quantum dot device further includes a container 1 and a lifting device 2.

Specifically, a container 1 is used to contain the quantum dot solution, the material of the container can ensure that the quantum dot solution is not polluted, and the container can resist the corrosion of the quantum dot solution, and the material of the container is preferably one of glass, ceramic and metal. And lifting the substrate 10 by using a lifting device 2, so that the substrate 10 is soaked in the quantum dot solution.

As shown in fig. 5, the substrate 10 includes an active region 11 and an inactive region 12, wherein a portion of the substrate 10 soaked by the quantum dot solution is the active region 11, and a portion of the substrate 10 not soaked by the quantum dot solution is the inactive region 12. The inactive area 12 is located at one side of the substrate 10, i.e. at the upper end of the substrate 10, and a boundary line L is provided between the inactive area 12 and the active area 11 to separate the inactive area 12 and the active area 11. The inactive area 12 has a width smaller than 50cm, and the distance L between the clamp 31 and the boundary is larger than 50um during clamping, so that the substrate 10 can be firmly clamped, and the clamp 31 and the active area 11 of the substrate can keep a certain distance, thereby preventing the clamp 31 from being polluted or corroded by the quantum dot solution.

Specifically, the ineffective area 12 includes the clamping area 121 and the boundary area 122, and it can be seen that, in step S2), the clamp 31 is clamped in the area of the substrate 10 as a partial ineffective area. The clamping area 121 is an area where the first and

second clamps

311 and 312 clamp the substrate 10 together, and the boundary area 122 is an area between the clamping area 121 and the active area 12. The width of the inactive area 12 is the sum of the widths of the clamping area 121 and the dividing area 122, wherein the width of the dividing area 122 is D, D is greater than 50um, the width of the clamping area 121 is D, D <50cm, which means that the width of the inactive area 12 is less than 50cm, and the distance L between the clamp 31 and the boundary is greater than 50um during clamping.

S4) controlling an angle adjuster to perform a tilt process on the substrate.

As shown in fig. 2, the holding device 3 further includes an angle adjuster 32 connected to the holder 31, and the substrate 10 is tilted by the angle adjuster 32 such that an included angle θ formed by the substrate 10 and a horizontal plane of the quantum dot solution is greater than 5 ° and less than 90 °. Preferably, the included angle θ is 15 °, 18 °, 20 °, 25 °, 28 °, 30 °, 45 °, 50 °, 55 °, 60 °, 65 °, 70 °, 75 °, 80 °, 85 °, 88 °, but is not limited thereto.

S5) controlling a lifting device to pull up the substrate at a constant speed, and forming undried quantum dot films on the surfaces of the two sides of the effective area of the substrate.

Specifically, the surface of the active region 11 of the substrate has a certain roughness when being soaked in the quantum dot solution. The angle adjuster 32 is controlled by a controller 4 to adjust an angle between the substrate 10 and the surface of the quantum dot solution, and the lifting device 2 is controlled by the controller 4 to move the substrate 10 upward. When the included angle is 5 degrees < theta <90 degrees, the uniform speed of the substrate 10 is 0.1um/s-10cm/s, and the quantum dot solution is uniformly formed into a film on the surfaces of the two sides of the active area 11 to form the undried quantum dot film 20. In this embodiment, a thinner quantum dot film layer is prepared, so the viscosity of the quantum dot solution is greater than 800cps, and the uniform pull-up speed of the substrate 10 is preferably 0.5um/s, 0.52um/s, 0.56um/s, 0.58um/s, 0.6um/s, but not limited thereto, as long as the substrate 10 has the uniform pull-up speed in the pull-up process, and the quantum dot solution can be uniformly formed on the two side surfaces of the active region 11. Of course, in actual operation, the material, concentration, and the like of the quantum dot solution are also taken into consideration, and an appropriate substrate pull-up speed is selected according to the conditions such as the material, concentration, and the like of the quantum dot solution.

S6) placing the substrate on a carrying table, and baking the substrate, wherein the two side surfaces of the substrate effective area form solidified quantum dot films.

As shown in fig. 6, the substrate 10 is placed on a stage 30, and the substrate 10 is sent to a baking device to be baked, so that the cured quantum dot films 20 are formed on the two side surfaces of the substrate active region 11.

In the prior art, in the preparation of a large-sized quantum dot film, especially an embedded quantum dot film (in cell QD fim), for example, in a Liquid Crystal Display (LCD) panel or an Organic Light Emitting Diode (OLED) panel, a quantum dot film is prepared before the emergent Light passes through red, green and blue (RGB) color resistance, and the uniformity and the Light Emitting characteristic of the quantum dot film are very important. However, in the conventional quantum dot film preparation process, the quantum dot film is generally prepared by spin coating or slit coating (slit coating), but in a considerable number of cases, the quantum dot nanoparticles are dispersed in a solvent, and the problems of concentration limitation and difficult dispersion exist, so that the quantum dot film is poor in uniformity, uneven in film thickness and unbalanced in dispersion concentration.

The embodiment provides a method for preparing a quantum dot film, wherein the quantum dot film is prepared in a soaking mode in the process of preparing the quantum dot film, the mode is favorable for forming the film on a substrate with a larger size, and the problems of concentration limitation and difficult dispersion of a quantum dot solution are solved, so that the uniformity, the uniform film thickness and the balance of dispersion concentration of the formed quantum dot film are ensured.

As shown in fig. 2 to 4, the present embodiment further provides a quantum dot device using the preparation method described above, which includes a container 1, a lifting device 2, a holding device 3, a controller 4, and an air blowing device 5.

The container 1 is used for loading quantum dot solution. The material of the container can ensure that the quantum dot solution is not polluted and can resist the corrosion of the quantum dot solution, and the material of the container is preferably one of glass, ceramics and metal. The lifting device 2 is arranged above the container 1. A gripping device 3 is mounted to the lifting device and faces one side of the container 1. The controller 4 is connected to the lifting device 2 and the holding device 3. The air blowing devices 5 are connected to the holding devices 3, respectively.

Wherein the clamping device 3 comprises at least one pair of clamps 31 and an angle adjuster 32, the angle adjuster 32 being connected to the clamps 31. The clamping device comprises a first clamp 311 and a second clamp 312. In this embodiment, the first clamp 311 and the second clamp 312 are respectively connected to two air blowing devices 5 through a pipe, and the air blowing devices 5 are air cylinders. Then, by driving the air blowing device 5, an air pressure difference is formed between the inside and the outside of the first and

second clamps

311 and 312, and the substrate 10 is held between the clamps 3 by the air pressure difference so as not to slip off due to gravity. The substrate 10 is tilted by using the angle adjuster 32, so that an included angle theta formed by the substrate 10 and a horizontal plane of the quantum dot solution is greater than 5 degrees and less than 90 degrees. Preferably, the included angle θ is 15 °, 18 °, 20 °, 25 °, 28 °, 30 °, 45 °, 50 °, 55 °, 60 °, 65 °, 70 °, 75 °, 80 °, 85 °, 88 °, but is not limited thereto.

The embodiment provides a quantum dot device, which is used for preparing a quantum dot film in a soaking mode, so that the quantum dot film is formed on a substrate with a larger size by using a quantum dot solution, and the problems of concentration limitation and difficult dispersion of the quantum dot solution are solved, so that the uniformity, the film thickness uniformity and the dispersion concentration balance of the formed quantum dot film are ensured.

The above detailed description is made on a device and a method for manufacturing a quantum dot film provided in the embodiments of the present application, and specific examples are applied in the present application to explain the principle and the implementation of the present application, and the description of the above embodiments is only used to help understanding the technical scheme and the core concept of the present application; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. An apparatus for preparing a quantum dot film, comprising:

a container for loading the quantum dot solution;

the lifting device is arranged above the container;

a gripping device mounted to the lifting device and facing a side of the container; and

and the controller is connected to the lifting device and the clamping device.

2. The apparatus of claim 1,

the clamping device includes:

at least one pair of clamps; and

at least one pair of blowing devices respectively connected to the clamps.

3. The apparatus of claim 1, further comprising an angle adjuster coupled between the clamp and the lifting device;

when the clamp clamps the substrate, the angle regulator can regulate the angle of the substrate, so that the included angle formed by the substrate and the horizontal plane of the quantum dot solution is greater than 5 degrees and smaller than 90 degrees.

4. The apparatus of claim 1,

the material of the container is one of glass, ceramic and metal.

5. A preparation method of a quantum dot film is characterized by comprising the following steps:

providing a substrate and the apparatus of claim 1;

controlling a clamping device to clamp the substrate;

6. The method for producing a quantum dot film according to claim 1,

in the step of clamping the substrate, the clamping device is provided with at least one pair of clamps and at least one pair of air blowing devices, and the at least one pair of air blowing devices are respectively arranged on one surfaces of the clamps, which are opposite to each other; wherein, the air blowing device is utilized to form air pressure on two sides of the substrate so as to clamp the substrate.

7. The method of claim 2, wherein the inactive region is located on one side of the substrate, and the inactive region and the active region have a boundary line;

in the step of clamping the substrate, the substrate is clamped,

and when the substrate is clamped, the clamp is clamped in the invalid area.

8. The method for producing a quantum dot film according to claim 3,

the inactive area has a width less than 50cm, and the distance between the jig and the boundary is greater than 50um when the jig is clamped.

9. The method for producing a quantum dot film according to claim 1,

in the step of pulling up the substrate,

the uniform pull-up speed of the substrate is 0.1um/s-10 cm/s.

10. The method for producing a quantum dot film according to claim 2,

between the substrate soaking step and the substrate pulling-up step, the method further comprises the following steps: