Full-color multifunctional micro-led display device and method based on photolithography technology, light source device

Abstract

The application discloses a full-color multifunctional Micro-LED display device and method based on a photoetching technology and a light source device, integrates red, green and near-infrared quantum dot pixel arrays through the photoetching technology, realizes high resolution, high color gamut, high contrast, low energy consumption display effects, and has additional functions of face recognition and multi-parameter physiological monitoring. The method comprises the following steps: accurately patterning a Micro-LED blue light chip array, using quantum dot photoresist as a light conversion layer to realize full-color display, and integrating touch sensing and flexible display functions. Through optimization of photoetching process parameters, the application can form a uniform and fine quantum dot pattern on the Micro-LED blue light chip array, significantly improves color performance and energy efficiency. The preparation method also has the advantages of high cost-effectiveness, high production efficiency and high yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of display technology and photoelectric sensing technology, in particular to a method for forming a red, green and near-infrared quantum dot pixel array on a blue Micro-LED chip through photolithography technology, which can not only realize full-color display of Micro-LED, but also integrate multiple functions of face recognition and detection. Especially, it relates to a full-color multifunctional Micro-LED display device and method based on photolithography technology, and a light source device. BACKGROUND

[0002] With the rapid development of information technology and intelligent devices, display technology has become an important medium for human-computer interaction. Although the current commercial display technologies such as liquid crystal (LCD) and organic light-emitting diode (OLED) have made significant progress in brightness, color, etc., there are still problems such as insufficient color saturation and high energy consumption. In addition, in recent years, with the rapid rise of biological sensing technologies such as face recognition and health monitoring, the market demand for multifunctional devices integrating display and sensing functions is increasing.

[0003] Micro-LED, as a new generation of display panel technology, has attracted widespread attention due to its advantages such as high brightness, high color gamut, low energy consumption, long life, etc. However, it is extremely difficult to grow RGB three-color chips on a large-area epitaxial substrate simultaneously. To overcome the difficulty of mass transfer, blue Micro-LED is usually used as an excitation light source, and red and green two-color quantum dot pixel arrays are used as a light conversion layer to convert blue light into red and green light to achieve high-efficiency full-color display. Currently, the methods for forming a light conversion layer using quantum dots mainly include nanoimprint technology, inkjet printing technology and photolithography technology, etc. However, nanoimprint technology has the disadvantages of low processing efficiency, low precision and uncontrollable transfer, inkjet printing technology has the problems of needle tip easy to shake and blockage, and ink droplets easy to form coffee ring, therefore, photolithography technology is considered as the most likely solution to realize large-area, high-efficiency and high-precision Micro-LED full-colorization. In addition, most of the current popular Micro-LED display devices lack sensing functions, which limits their application potential in the field of intelligent devices.

[0004] The integration of infrared light sources on mobile phone screens has great market value in terms of the following aspects: 1. Biometric identification technology: Infrared light sources are widely used in biometric identification technology in smartphones, such as face recognition and iris recognition, which improve the security and convenience of devices. For example, Apple's iPhone has implemented FaceID face recognition technology. 2. Camera system: Infrared light sources can enhance the performance of smartphone cameras in low-light environments, providing clearer night shooting effects. 3. Data transmission: Infrared light sources also have applications in data transmission, such as using infrared communication to transfer files or settings between devices. 4. Medical health monitoring: With the increasing popularity of health monitoring functions in smartphones, infrared light sources can be used to monitor physiological indicators such as heart rate and blood pressure. The application of infrared light sources is expanding in various fields, including consumer electronics, smart cockpits / advanced driver assistance systems, autonomous driving, and industrial / logistics / home appliance automation. In summary, the application of infrared light sources in the field of smartphones not only enhances the functionality of the phone but also drives the development of related technologies and the expansion of the market. With the continuous advancement of technology and the growth of market demand, the application value of infrared light sources in the mobile phone market will continue to increase.

[0005] Common infrared light sources generally have high cost, low conversion efficiency, and large devices that are difficult to integrate into screens. SUMMARY

[0006] The present application can overcome the above difficulties by combining infrared quantum dots with Micro-LED technology through photolithography technology. Quantum dots are a class of semiconductor nanomaterials with unique physical and chemical properties. They are usually composed of II-VI group (such as CdSe, CdTe), III-V group (such as InP, InAs), or IV-VI group (such as PbS, PbSe) materials. The size of quantum dots can range from a few nanometers to a few tens of nanometers. This small size gives them unique quantum confinement effects. By adjusting the size of the quantum dots, ultraviolet or blue light can be converted into different light colors from visible light to near-infrared. Quantum dots have a wide absorption range, adjustable wavelength, high color purity, and high fluorescence efficiency, and are widely used in biological imaging, detection, backlight display, white light LED, sensing, and other fields. Near-infrared quantum dots have high penetration and low autofluorescence background in biological tissues, making them ideal materials for face recognition and physiological parameter detection.

[0007] The specific embodiments of the present application are as follows: a full-color multifunctional Micro-LED display device based on photolithography technology, comprising a blue Micro-LED excitation layer, a substrate, a quantum dot light conversion layer, a Micro-LED blue chip, and a protective layer.

[0008] A substrate is arranged on the blue light Micro-LED excitation layer, and the substrate and the blue light Micro-LED excitation layer form a cavity; a plurality of array-arranged Micro-LED blue light chips are arranged on the blue light Micro-LED excitation layer and located in the cavity;

[0009] The quantum dot light conversion layer comprises a plurality of array-arranged red light quantum dot pixels, green light quantum dot pixels and near-infrared light quantum dot pixels; the quantum dot light conversion layer further comprises a protective layer; and the quantum dot light conversion layer is located on the substrate;

[0010] The red light quantum dot pixels are used for converting the blue light emitted by the array of blue light Micro-LED chips into red light;

[0011] The green light quantum dot pixels are used for converting the blue light emitted by the array of blue light Micro-LED chips into green light;

[0012] The near-infrared light quantum dot pixels are used for converting the blue light emitted by the array of blue light Micro-LED chips into near-infrared light;

[0013] The red light quantum dot pixels, the green light quantum dot pixels and the near-infrared light quantum dot pixels are encapsulated by the protective layer, and the protective layer is a colorless and transparent material.

[0014] The application further provides a preparation method of the full-color multifunctional Micro-LED display device based on the photolithography technology, and specific steps of the method are as follows:

[0015] Step S1: patterning the Micro-LED blue light chips on the Micro-LED excitation layer;

[0016] Step S2: cleaning the substrate and chemically modifying the surface of the substrate; and arranging the substrate on the Micro-LED excitation layer, so that the Micro-LED blue light chips are located in the cavity formed by the blue light Micro-LED excitation layer and the substrate;

[0017] Step S3: adding the surfactant, the inorganic additive and the light scattering particle into the photoresist mother liquor according to the formula amount, and stirring until the surfactant, the inorganic additive and the light scattering particle are fully dissolved to obtain the photoresist mother liquor containing the additives;

[0018] Step S4: dispersing the red quantum dots in the photoresist mother liquor containing the surfactant and the inorganic additive according to the formula amount, and uniformly dispersing to obtain the red quantum dot photoresist; the same operation steps are used to obtain the green quantum dot photoresist and the near-infrared quantum dot photoresist;

[0019] Step S5: coating the red quantum dot photoresist obtained in step S4 on the substrate to obtain a uniformly distributed red quantum dot photoresist film;

[0020] Step S6: The red quantum dot photoresist film obtained in step S5 is subjected to pre-baking treatment, local exposure, development and post-baking treatment, the red quantum dot photoresist film is cured to form a quantum dot photoconversion layer of red pixel points; the operations of steps S5 and S6 are repeated to obtain quantum dot photoconversion layers of green and near-infrared light pixel points.

[0021] Step S7: An inorganic oxide film layer for water and oxygen isolation is deposited on the phosphor coating by ALD or MOCVD to protect the phosphor.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] In the prior art, the Micro-LED display device based on a blue chip generally only integrates red and green quantum dots to form a pixel array, which is generally realized by an inkjet printing technology. Although this method saves materials and has low cost, its working efficiency is relatively low, and it is only suitable for application in low-resolution display devices and is difficult to meet the demand for high-resolution display. In view of the limitations of the prior art, the present application proposes a new preparation method of a display device to further expand the application range of the Micro-LED display technology. In the red and green quantum dot photoconversion layer of the existing Micro-LED based on a blue chip, the present application innovatively introduces near-infrared quantum dots, and accurately forms a red, green and near-infrared three-color pixel array by using advanced photolithography technology. Through this improvement, the present application not only can realize full-color display and enhance the visual experience of the display device, but more importantly, the newly introduced near-infrared quantum dots endow the display device with advanced functions of face recognition and physiological parameter detection, which greatly expand the application scenarios of the Micro-LED display device and make it have potential application value in the fields of security authentication and health detection. In addition, compared with the inkjet printing technology, the photolithography technology has more obvious advantages in the preparation of high-resolution pixel arrays. The photolithography technology can realize more fine patterning, has high efficiency, and has mature production equipment support, and is suitable for manufacturing high-resolution display devices. The preparation method of the display device of the present application not only improves the display quality, but also increases the practical functions, while ensuring the high efficiency and low cost of the preparation process, which provides a new direction for the development of the Micro-LED display technology and has wide application prospects in the fields of intelligent terminals, security monitoring and medical health. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 : Schematic diagram of a display device;

[0025] Figure 2 : Emission spectrum diagram of red quantum dot pixel points under 450 nm excitation;

[0026] Figure 3 Figure 4 is an emission spectrum diagram of a green quantum dot pixel point under 450 nm excitation;

[0027] Figure 4 Figure 5 is an emission spectrum diagram of a near-infrared quantum dot pixel point under 450 nm excitation.

[0028] In the figure, 1 is a blue light Micro-LED excitation layer, 2 is a substrate, 3 is a quantum dot light conversion layer, 301 is a red light quantum dot pixel, 302 is a green light quantum dot pixel, 303 is a near-infrared light quantum dot pixel, 4 is a protective layer, and 5 is a Micro-LED blue light chip. DETAILED DESCRIPTION

[0029] The application will be further described in conjunction with specific embodiments. It should be understood that the following examples are only illustrative and explanatory of the application, but should not be interpreted as limiting the scope of protection of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application should be included in the protection scope of the application.

[0030] The application provides a full-color multifunctional Micro-LED display device based on a photolithography technology, as shown in Figure 1. Figure 1 The device includes a blue light Micro-LED excitation layer 1, a substrate 2, a quantum dot light conversion layer 3, a Micro-LED blue light chip 5, and a protective layer 4.

[0031] The substrate 2 is arranged on the blue light Micro-LED excitation layer 1, and the substrate 2 and the blue light Micro-LED excitation layer 1 form a cavity; a plurality of array-arranged Micro-LED blue light chips 5 are arranged on the blue light Micro-LED excitation layer 1 and located in the cavity; the structure can effectively improve the light-emitting efficiency and uniformity of the Micro-LED.

[0032] The blue light Micro-LED excitation layer 1 includes a plurality of array-arranged blue light Micro-LED chips 5, the emission wavelength of which is between 430 nm and 470 nm, and the chip size is between 1 μm and 50 μm.

[0033] The substrate 2 can be a hard substrate such as transparent glass or a flexible substrate such as a polyimide film, and the substrate 2 needs to be cleaned and treated by ultraviolet ozone before the quantum dot light conversion layer 3 is prepared thereon.

[0034] The quantum dot light conversion layer 3 includes a plurality of array-arranged red light quantum dot pixels 301, green light quantum dot pixels 302, and near-infrared light quantum dot pixels 303; the quantum dot light conversion layer 3 is further provided with a protective layer 4; and the quantum dot light conversion layer 3 is located on the substrate 2.

[0035] The red quantum dot pixel 301 is used for converting blue light emitted by the blue light Micro-LED chip array into red light;

[0036] The green quantum dot pixel 302 is used for converting blue light emitted by the blue light Micro-LED chip array into green light;

[0037] The near-infrared quantum dot pixel 303 is used for converting blue light emitted by the blue light Micro-LED chip array into near-infrared light;

[0038] The red quantum dot pixel 301, the green quantum dot pixel 302 and the near-infrared quantum dot pixel 303 are encapsulated by a protective layer 4, and the protective layer 4 is colorless and transparent.

[0039] The application further provides a preparation method of the full-color multifunctional Micro-LED display device based on the photoetching technology.

[0040] Step S2: cleaning the substrate 2 and performing chemical modification on the substrate surface; and placing the substrate 2 on the Micro-LED excitation layer 1, so that the Micro-LED blue light chip 5 is located in the cavity formed by the blue light Micro-LED excitation layer 1 and the substrate 2.

[0041] Step S3: adding a surfactant, an inorganic additive and light scattering particles into a photoresist mother liquor according to a formula amount, and stirring until the surfactant, the inorganic additive and the light scattering particles are fully dissolved to obtain the photoresist mother liquor containing the additives;

[0042] Step S4: dispersing red quantum dots in the photoresist mother liquor containing the surfactant and the inorganic additive according to a formula amount, and uniformly dispersing to obtain a red quantum dot photoresist; and performing the same operation steps to obtain a green quantum dot photoresist and a near-infrared quantum dot photoresist;

[0043] Step S5: coating the red quantum dot photoresist obtained in step S4 on the treated substrate 2 to obtain a uniformly distributed red quantum dot photoresist film;

[0044] Step S6: performing pre-baking treatment, local exposure, development and post-baking treatment on the red quantum dot photoresist film obtained in step S5, so that the red quantum dot photoresist film is solidified to form a quantum dot light conversion layer of red pixels; and repeating the operation of step S5 and step S6 to obtain quantum dot light conversion layers of green and near-infrared pixels;

[0045] Step S7: using an ALD or MOCVD method to entirely evaporate and deposit an inorganic oxide film layer on the phosphor material coating, so as to protect the phosphor material.

[0046] Further, the photoresist mother liquor comprises a main resin and a solvent.

[0047] Further, the main resin can be selected from one or more of epoxy resin, acrylic resin, phenolic resin, polyvinyl cinnamate; the solvent can be selected from one or more of ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, propylene glycol ethyl ether, dipropylene glycol methyl ether, propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, xylene, dimethylformamide, dimethyl sulfoxide, methyl isobutyl ketone.

[0048] Further, the mass fraction of the quantum dots is 1-30%.

[0049] Further, the green and red quantum dots are one or more of II-VI semiconductor quantum dots, III-V semiconductor quantum dots, and perovskite quantum dot materials, wherein the red quantum dots have an emission wavelength of 610-640 nm and a half-peak width of <40 nm, the green quantum dots have an emission wavelength of 510-540 nm and a half-peak width of <40 nm, and the near-infrared quantum dots are one or more of II-VI semiconductor quantum dots, III-V semiconductor quantum dots, IV-VI semiconductor quantum dots, I-III-VI semiconductor quantum dots, perovskite quantum dots, and carbon quantum dot materials, having an emission wavelength of 800-2000 nm and a half-peak width of <100 nm.

[0050] Further, the mass fraction of the inorganic additive is 0.01-10%.

[0051] Further, the mass fraction of the surfactant is 0.1-2%.

[0052] Further, the mass fraction of the light scattering particles is 0.01-1%.

[0053] Further, the surfactant can be selected from non-ionic and ionic types. Non-ionic surfactants generally contain long non-polar hydrocarbon groups and short polar groups, such as fatty acid polyoxyethylene glycol esters and polyols. Ionic surfactants include anionic (such as stearate and phosphate), cationic (such as cetyltrimethylammonium bromide and dodecylpyridinium chloride), and zwitterionic (such as amino acids, betaine, and imidazoline).

[0054] Further, the inorganic additive can be selected from one or more of lithium chloride, magnesium chloride, aluminum chloride, calcium chloride, vanadium chloride, zinc chloride, cadmium chloride, mercury chloride, lead chloride, lithium bromide, magnesium bromide, aluminum bromide, calcium bromide, zinc bromide, cadmium bromide, calcium nitrate, cadmium nitrate, silver nitrate.

[0055] Further, the light scattering particles are one or more of organic photo-silicon, silicon dioxide, and calcium carbonate.

[0056] Further, the exposure light source in step S6 is an ultraviolet light source with a wavelength of 365 nm, 405 nm, or 436 nm, and the exposure energy is 50-1500 mJ / cm 2 .

[0057] Further, the developing in step S6 is to wash away the uncured photoresist with a developing solution to form a quantum dot pixel array; the developing solution is an alkaline reagent selected from, but not limited to, a potassium hydroxide aqueous solution and a tetramethylammonium hydroxide aqueous solution; and the developing time is 5-200 s.

[0058] Further, the pre-baking in step S6 is baking at a temperature of 80-110℃ for 30-300 s, and the post-baking is baking at a temperature of 130-200℃ for 10-100 min to further cure the quantum dot photoresist film; the film thickness of the formed quantum dot photoconversion layer is 1-20 μm, and the line width is 1-200 μm.

[0059] Further, the substrate cleaning in step S2 specifically includes: sequentially placing the substrate in a cleaning agent, isopropyl alcohol, ethanol, and deionized water, and ultrasonically cleaning for 5-10 minutes; blowing the cleaned substrate dry with nitrogen and placing it in an 80℃ oven for baking for 2 hours; and placing the treated substrate in a cavity of an ultraviolet ozone cleaning machine, processing for 10-30 minutes at a power of 50-300 W, and further cleaning and chemically modifying the surface of the substrate by using ultraviolet light and ozone to improve the hydrophilicity of the substrate.

[0060] The application also provides a full-color multifunctional Micro-LED display device based on a photoetching technology, which comprises a blue light Micro-LED substrate, a photoresist mother liquor, red quantum dots, green quantum dots, near-infrared (NIR) quantum dots, and inorganic additives, a surfactant, and a light diffuser dispersed uniformly in the photoresist mother liquor; the surfactant can form a homogeneous system with the quantum dots in the photoresist mother liquor by stirring to improve the polarity of the quantum dots, so that the quantum dots can be dispersed in a polar solvent ester commonly used in photoresist, such as PGMEA, to maintain the long-term colloidal stability of the nanoparticles in the photoresist; meanwhile, the inorganic additives can form a coordination with the quantum dots by serving as a ligand and hanging on the surface of the quantum dots to reduce the surface defects of the quantum dots and improve the fluorescence efficiency of the quantum dots; in addition, light scattering particles are usually added in the photoconversion layer made of the quantum dot photoresist to improve the light recycling of blue light in the conversion layer, increase the absorption of the quantum dots to the excitation light, increase the photoconversion efficiency, and improve the color purity of the light.

[0061] This invention also proposes a Micro-LED multifunctional multicolor display and infrared light source device based on a variety of fluorescent materials. The micro-LED structure, from bottom to top, includes a driving circuit and a full-color multifunctional Micro-LED display device fabricated based on photolithography technology. Specific Implementation Example 1

[0063] Embodiment 1 of this invention provides a red quantum dot photoresist, comprising a photoresist mother liquor, red quantum dots, inorganic additives, surfactants, and light-scattering particles uniformly dispersed in the mother liquor. The photoresist has a solid content of 40% and comprises a base rubber and a solvent. The base rubber is acrylic resin and phenolic resin, and the solvent is propylene glycol acetate. The red quantum dots are CdSe, with an emission wavelength of 630 nm and a full width at half maximum (FWHM) of 23 nm, accounting for 20% of the mass fraction in the photoresist. The inorganic additive is magnesium bromide, accounting for 1% of the mass fraction in the photoresist. The surfactant is hexadecyltrimethylammonium bromide, accounting for 0.5% of the mass fraction in the photoresist. The light-scattering particles are silicon dioxide, accounting for 0.05% of the mass fraction in the photoresist. Figure 2 The image shown is the emission spectrum of the red quantum dot pixel under 450 nm excitation according to the present invention. Specific Implementation Example 2

[0065] Embodiment 2 of the present invention provides a green quantum dot photoresist, comprising a photoresist mother liquor, green quantum dots, inorganic additives, surfactants, and light-scattering particles uniformly dispersed in the photoresist mother liquor. The photoresist has a solid content of 40%, comprising a base rubber and a solvent. The base rubber is acrylic resin and phenolic resin, and the solvent is propylene glycol acetate. The green quantum dots are CdSe, with an emission wavelength of 525 nm and a full width at half maximum (FWHM) of 20 nm, accounting for 20% of the mass fraction in the photoresist. The inorganic additive is magnesium bromide, accounting for 1% of the mass fraction in the photoresist. The surfactant is hexadecyltrimethylammonium bromide, accounting for 0.5% of the mass fraction in the photoresist. The light-scattering particles are silicon dioxide, accounting for 0.05% of the mass fraction in the photoresist. Figure 3 The image shows the emission spectrum of a green quantum dot pixel under 450 nm excitation. Specific Implementation Example 3

[0067] Embodiment 3 of the present application provides a near-infrared quantum dot photoresist, which comprises a photoresist mother liquor, near-infrared quantum dots uniformly dispersed in the photoresist mother liquor, inorganic additives, a surfactant and light scattering particles. The solid content of the photoresist is 40%, which comprises a main rubber and a solvent, the main rubber is an acrylic resin and a phenolic resin, and the solvent is propylene glycol methyl acrylate; the near-infrared quantum dots are PbS, the emission wavelength is 1200 nm, the half peak width is 70 nm, and the mass fraction in the photoresist is 20%; the inorganic additive is magnesium bromide, the mass fraction in the photoresist is 1%; the surfactant is cetyltrimethylammonium bromide, the mass fraction in the photoresist is 0.5%; and the light scattering particles are silicon dioxide, the mass fraction in the photoresist is 0.05%. As shown in FIG. 4, it is an emission spectrum diagram of a near-infrared quantum dot pixel point under 450 nm excitation. Figure 4

[0068] A preparation method of a full-color multifunctional Micro-LED display device based on a photoetching technology, the specific steps are as follows:

[0069] Step S1: patterning the Micro-LED blue light chip 5 on the Micro-LED excitation layer 1;

[0070] Step S2: cleaning the substrate 2 and chemically modifying the surface of the substrate 2; placing the substrate 2 on the Micro-LED excitation layer 1, so that the Micro-LED blue light chip 5 is located in the cavity formed by the blue light Micro-LED excitation layer 1 and the substrate 2;

[0071] Step S3: adding the surfactant, inorganic additive and light scattering particle into the photoetching mother liquor according to the formula amount, and stirring until fully dissolved to obtain a photoresist mother liquor containing additives;

[0072] Step S4: dispersing the red quantum dots in the photoresist mother liquor containing the above-mentioned surfactant and inorganic additive according to the formula amount, and uniformly dispersing to obtain a red quantum dot photoresist; the same operation steps are used to obtain a green quantum dot photoresist and a near-infrared quantum dot photoresist;

[0073] Step S5: coating the red quantum dot photoresist obtained in step S4 on the blue light Micro-LED substrate to obtain a uniformly distributed red quantum dot photoresist film;

[0074] Step S6: heat treating the red quantum dot photoresist film obtained in step S5 at a temperature of 90°C for 120s; then using a wavelength of 365 nm and an energy of 200 mJ / cm 2 ​exposure is completed, the unhardened photoresist is washed away by using a 2.38% tetramethylammonium hydroxide aqueous solution as a developing solution for developing for 40 s; after the developing is completed, the quantum dot photoresist film is placed in a temperature condition of 140°C for baking for 30 min for further curing, so as to form a quantum dot photoconversion layer of red pixel points; the operations of steps S5 and S6 are repeated to obtain quantum dot photoconversion layers of green and near-infrared light pixel points; the quantum dot photoconversion layer having a red, green, and near-infrared three-color pixel array obtained through photoetching has a thickness of 4.3 μm and a line width of 10 μm.

[0075] Step S7: An ALD method is used to evaporate an aluminum oxide film as a water and oxygen barrier layer on the fluorescent material coating for protecting the fluorescent material.

[0076] Further, the wavelength of the Micro-LED blue light chip 5 is 450 nm, and the size of the chip is 20 μm.

[0077] Further, the cleaning of the substrate 2 in step S2 is specifically as follows: the glass substrate is sequentially placed in a cleaning agent, isopropyl alcohol, ethanol, and deionized water, and is ultrasonically cleaned for 10 min each time; the cleaned substrate is dried by blowing nitrogen and is placed in an 80°C oven for baking for 2 hours; the treated glass substrate is placed in a cavity of an ultraviolet ozone cleaning machine, a power of 100 W is used, and the glass substrate is treated for 30 min; the surface of the glass substrate is further cleaned and chemically modified by using ultraviolet light and ozone, so as to improve the hydrophilicity of the glass substrate.

Claims

1. A full-color multifunctional Micro-LED display device based on photolithography technology, characterized in that, The device comprises a blue light Micro-LED excitation layer, a substrate, a quantum dot light conversion layer, a Micro-LED blue light chip and a protective layer. The substrate is arranged on the blue light Micro-LED excitation layer, and the substrate and the blue light Micro-LED excitation layer form a cavity; a plurality of arrayed Micro-LED blue light chips are arranged on the blue light Micro-LED excitation layer and located in the cavity. The quantum dot light conversion layer comprises a plurality of arrayed red light quantum dot pixels, green light quantum dot pixels and near-infrared light quantum dot pixels; the quantum dot light conversion layer further comprises a protective layer; the quantum dot light conversion layer is located on the substrate. The red light quantum dot pixel is used for converting the blue light emitted by the arrayed blue light Micro-LED chips into red light. The green light quantum dot pixel is used for converting the blue light emitted by the arrayed blue light Micro-LED chips into green light. The near-infrared light quantum dot pixel is used for converting the blue light emitted by the arrayed blue light Micro-LED chips into near-infrared light. The red light quantum dot pixel, the green light quantum dot pixel and the near-infrared light quantum dot pixel are encapsulated by the protective layer, and the protective layer is a colorless transparent material.

2. The apparatus of claim 1, wherein, The Micro-LED blue light chip is suitable for a wavelength of 430-470 nm, and the chip size is between 1-50 μm.

3. A method for preparing a full-color multifunctional Micro-LED display device based on a photolithography technology, characterized in that, The specific steps of the method are as follows: Step S1: patterning the Micro-LED blue light chip on the Micro-LED excitation layer; Step S2: cleaning the substrate and chemically modifying the surface of the substrate; arranging the substrate on the Micro-LED excitation layer, and forming a cavity between the substrate and the blue light Micro-LED excitation layer, so that the Micro-LED blue light chip is located in the cavity formed by the blue light Micro-LED excitation layer and the substrate; Step S3: adding the surfactant, the inorganic additive and the light scattering particle into the photoresist mother liquor according to the formula amount, stirring until fully dissolved to obtain the photoresist mother liquor containing the additive; Step S4: dispersing the red quantum dots in the photoresist mother liquor containing the surfactant and the inorganic additive according to the formula amount, and uniformly dispersing to obtain a red quantum dot photoresist; The same operation steps are used to obtain a green quantum dot photoresist and a near-infrared quantum dot photoresist; Step S5: coating the red quantum dot photoresist obtained in step S4 on the substrate to obtain a uniformly distributed red quantum dot photoresist film; Step S6: performing pre-baking treatment, local exposure, development and post-baking treatment on the red quantum dot photoresist film obtained in step S5, solidifying the red quantum dot photoresist film to form a quantum dot light conversion layer of red pixel points; repeating the operation of step S5 and step S6 to obtain quantum dot light conversion layers of green and near-infrared light pixel points; Step S7: using ALD or MOCVD to deposit an inorganic oxide film layer on the fluorescent material coating, which protects the fluorescent material.

4. The method of claim 3, wherein, The photoresist mother liquor comprises a main resin and a solvent; the main resin is selected from one or more of epoxy resin, acrylic resin, phenolic resin, and polyvinyl cinnamate; and the solvent is selected from one or more of ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol butyl ether, propylene glycol ethyl ether, dipropylene glycol methyl ether, propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, xylene, dimethylformamide, dimethyl sulfoxide, and methyl isobutyl ketone.

5. The method of claim 3, wherein, The mass fraction of the quantum dots is 1-30%.

6. The method of claim 3, wherein, The green and red quantum dots are one or more of II-VI semiconductor quantum dots, III-V semiconductor quantum dots, and perovskite quantum dot materials; the red quantum dots have an emission wavelength of 610-640 nm and a half-peak width of less than 40 nm; the green quantum dots have an emission wavelength of 510-540 nm and a half-peak width of less than 40 nm; and the near-infrared quantum dots are one or more of II-VI semiconductor quantum dots, III-V semiconductor quantum dots, IV-VI semiconductor quantum dots, I-III-VI semiconductor quantum dots, perovskite quantum dots, and carbon quantum dot materials, and have an emission wavelength of 800-2000 nm and a half-peak width of less than 100 nm.

7. The method of claim 3, wherein, The mass fraction of the inorganic additive is 0.01-10%.

8. The method of claim 3, wherein, The mass fraction of the surfactant is 0.1-2%.

9. The method of claim 3, wherein, The mass fraction of the light scattering particles is 0.01-1%.

10. The method of claim 3, wherein, The surfactant is selected from non-ionic and ionic surfactants; the non-ionic surfactant contains long non-polar hydrocarbon groups and short polar groups, and includes fatty acid polyoxyethylene glycol esters and polyhydric alcohols; the ionic surfactant includes anionic surfactants, including stearate and phosphate; cationic surfactants, including hexadecyl trimethyl ammonium bromide and dodecyl pyridinium chloride; and zwitterionic surfactants, including amino acids, betaine, and imidazoline.

11. The method of claim 3, wherein, The inorganic additive is selected from one or more of lithium chloride, magnesium chloride, aluminum chloride, calcium chloride, vanadium chloride, zinc chloride, cadmium chloride, mercury chloride, lead chloride, lithium bromide, magnesium bromide, aluminum bromide, calcium bromide, zinc bromide, cadmium bromide, calcium nitrate, cadmium nitrate, and silver nitrate.

12. The method of claim 3, wherein, The light scattering particles are one or more of organic light silicon, silicon dioxide, and calcium carbonate.

13. The method of claim 3, wherein, The exposure light source in step S6 is an ultraviolet light source with a wavelength of 365 nm, 405 nm, or 436 nm, and the exposure energy is 50-1500 mJ / cm 2 .

14. The method of claim 3, wherein, The developing in step S6 is washing of the uncured photoresist with a developing solution to form a quantum dot pixel array; the developing solution is an alkaline reagent selected from, but not limited to, aqueous potassium hydroxide and aqueous tetramethylammonium hydroxide; and the developing time is 5-200 s.

15. The method of claim 3, wherein, The pre-baking in step S6 is baking at a temperature of 80-110°C for 30-300 s; and the post-baking is baking at a temperature of 130-200°C for 10-100 min to further cure the quantum dot photoresist film; the formed quantum dot photoconversion layer has a film thickness of 1-20 μm and a line width of 1-200 μm.

16. The method of claim 3, wherein, The cleaning of the substrate and the chemical modification of the substrate surface are specifically as follows: the substrate is sequentially placed into a cleaning agent, isopropanol, ethanol and deionized water, and ultrasonic cleaning is performed for 5-10 minutes; the cleaned substrate is dried by blowing nitrogen, and is placed in an 80 DEG C oven for baking for 2 hours; high-transparency glass is selected as the substrate; the treated substrate is placed into a cavity of an ultraviolet-ozone cleaning machine, a power of 50-300 W is used, and processing is performed for 10-30 minutes; the substrate surface is further cleaned and chemically modified by using ultraviolet light and ozone, and the hydrophilicity of the substrate is improved.

17. A multi-functional multi-color display and infrared light source device based on a plurality of fluorescent materials, characterized in that, The device comprises, from bottom to top, a driving circuit and the display device of any one of claims 1-2.

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