Method for continuously producing perovskite quantum dot light-emitting film without solvent

Abstract

The invention belongs to the technical field of processing and forming of semiconductor materials, and particularly relates to a method for continuously producing a perovskite quantum dot light-emitting film without a solvent. The preparation method comprises the following steps: mixing cesium stearate, lead stearate, organic halide salt, a surfactant and an ultrahigh organic molecule compound to obtain a perovskite precursor; the perovskite precursor is subjected to melt extrusion, the perovskite precursor is subjected to an ionic combination reaction in the melt extrusion process, a perovskite quantum dot melt is generated in situ in the ultrahigh organic molecule compound fluid, and a mixed melt system is obtained; the mixed melting system is subjected to curtain coating, cooling, extension and rolling in sequence, and the perovskite quantum dot light-emitting film is obtained. The method is simple and efficient, and the prepared perovskite quantum dot light-emitting film is large in area and high in light-emitting efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of processing and forming of semiconductor materials, and in particular relates to a method for continuously producing a perovskite quantum dot luminescent film without solvent. Background Art

[0002] With the rapid development of the information society, higher requirements are placed on the use of display materials in future multi-scenario and high-compatibility applications, such as large size, flexibility, ultra-lightness and ultra-thinness. As a strong candidate for the new generation of display materials, perovskite quantum dot materials have made significant progress in display applications. However, the preparation of large-area quantum dot films is currently limited by the solution process, facing many problems such as uneven film formation, poor compatibility and adhesion of quantum dots to flexible substrates, a sharp drop in quantum yield after curing of liquid quantum dots, and environmental pollution caused by the use of large amounts of organic solvents. These problems limit its production and promotion in industrialization. Therefore, it is urgent to develop a new method for preparing quantum dot films to meet the application needs of modern new display materials.

[0003] To this end, a research team encapsulated perovskite quantum dots into a glass matrix, and then mixed them with polymers to prepare quantum dot films by a melting method (Lin, Jidong, et al. "Ultra-Stable Yellow Monolithic Perovskite Quantum Dots Film for Backlit Display." Advanced Functional Materials (2024): 2314795.), realizing the preparation of all-solid-phase quantum dot films. However, this method still requires pre-synthesis of quantum dots, and quantum dot synthesis requires ultra-high temperature (>1000°C) sintering, which increases the difficulty and complexity of the method and increases the preparation cost. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method for solvent-free continuous production of perovskite quantum dot luminescent film, which is simple and efficient, and the produced perovskite quantum dot luminescent film has a large area and high luminescent efficiency.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for continuously producing a perovskite quantum dot luminescent film without solvent, comprising the following steps:

[0007] Cesium stearate, lead stearate, an organic halide salt, a surfactant and an ultra-high organic molecular compound are mixed to obtain a perovskite precursor;

[0008] The perovskite precursor is melt-extruded, and during the melt-extrusion process, the perovskite precursor undergoes an ionization reaction to generate a perovskite quantum dot melt in situ inside the ultra-high organic molecular compound fluid to obtain a mixed melt system;

[0009] The mixed molten system is sequentially cast, cooled, stretched and rolled up to obtain a perovskite quantum dot luminescent film.

[0010] Preferably, the ultra-high organic molecular weight compound includes one or more of polyolefins and their derivatives, polyesters, polyaldehydes, polyamides, polyols and polynitrile.

[0011] Preferably, the temperature of the melt extrusion is 100-250°C.

[0012] Preferably, the ionization reaction is carried out in an air atmosphere; and the time of the ionization reaction is 1 to 2 minutes.

[0013] Preferably, the casting line speed is 0.1 to 10 m / min.

[0014] Preferably, the organic halide salt includes one or more of dibromotriphenylphosphine, octadecylamine iodide and oleylamine chloride.

[0015] Preferably, the surfactant comprises octadecylamine and octadecyl acid; the molar ratio of octadecylamine to octadecyl acid is 1 to 2:1.

[0016] Preferably, the total mass of the cesium stearate, lead stearate and organic halide salt accounts for 2-10% of the mass of the ultrahigh organic molecular compound.

[0017] Preferably, the mixing is carried out under stirring; the stirring rate is 100 to 2000 rpm; and the mixing time is 3 to 5 minutes.

[0018] The present invention also provides a perovskite quantum dot luminescent film prepared by the method described in the above technical solution, wherein the perovskite quantum dot luminescent film has a thickness of 0.1 to 1 mm and a luminescent efficiency of 40 to 90%.

[0019] The invention provides a method for solvent-free continuous production of a perovskite quantum dot luminescent film, comprising the following steps: mixing cesium stearate, lead stearate, an organic halide salt, a surfactant and an ultra-high organic molecular compound to obtain a perovskite precursor; melt-extruding the perovskite precursor, during the melt-extrusion process, the perovskite precursor undergoes an ionization reaction to in-situ generate a perovskite quantum dot melt inside an ultra-high organic molecular compound fluid to obtain a mixed melt system; and sequentially casting, cooling, extending and winding the mixed melt system to obtain a perovskite quantum dot luminescent film.

[0020] The present invention combines highly processable ultra-high organic molecular compounds and high luminous efficiency perovskite materials, and utilizes melt extrusion to induce the perovskite precursor to grow into quantum dots in situ on the surface of the ultra-high organic molecular compound carrier. The quantum dot / ultra-high organic molecular compound melt is prepared into a large-area, high-luminous-efficiency, uniform composite luminescent film by casting and stretching. The method provided by the present invention has high production efficiency, can realize the preparation of large-area luminescent films of 8m / min, and does not require the pre-synthesis and purification steps of quantum dot materials, simplifies the process, and avoids the use of organic solvents. All raw materials used are solid, realizing 100% utilization of raw materials, avoiding the generation of chemical waste, and the quantum yield of the obtained quantum dot luminescent film can reach up to 80%. The present invention provides a simple process, high efficiency, low cost, green and environmentally friendly, continuous all-solid-state quantum dot film-forming method, which realizes large-area, high-yield, batch in-situ preparation of high-efficiency quantum dot luminescent films. Moreover, by adjusting the types of organic halide salts, the universal preparation of multicolor luminescent films can be achieved. By adjusting the types of ultra-high organic molecular compounds, the preparation of quantum dot luminescent films with different ductility, flexibility, and transmittance can be achieved to meet the application of different display scenarios. It has great development value and commercial prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a physical photo of the perovskite quantum dot luminescent film prepared in Example 1;

[0022] Figure 2 The fluorescence spectrum of the perovskite quantum dot luminescent film prepared in Example 1;

[0023] Figure 3 The fluorescence spectrum of the perovskite quantum dot luminescent film prepared in Example 2;

[0024] Figure 4 This is the fluorescence spectrum of the perovskite quantum dot luminescent film prepared in Example 3. DETAILED DESCRIPTION

[0025] The present invention provides a method for continuously producing a perovskite quantum dot luminescent film without solvent, comprising the following steps:

[0026] Cesium stearate, lead stearate, an organic halide salt, a surfactant and an ultra-high organic molecular compound are mixed to obtain a perovskite precursor;

[0027] The perovskite precursor is melt-extruded, and during the melt-extrusion process, the perovskite precursor undergoes an ionization reaction to generate a perovskite quantum dot melt in situ inside the ultra-high organic molecular compound fluid to obtain a mixed melt system;

[0028] The mixed molten system is sequentially cast, cooled, stretched and rolled up to obtain a perovskite quantum dot luminescent film.

[0029] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used in the preparation, and commercially available products known to those skilled in the art can be used.

[0030] The invention mixes cesium stearate, lead stearate, an organic halogenated salt, a surfactant and an ultra-high organic molecular compound to obtain a perovskite precursor.

[0031] In the present invention, the surfactant preferably includes octadecylamine and octadecanoic acid; the molar ratio of octadecylamine and octadecanoic acid is preferably (1-2):1, more preferably 2:1; the molar ratio of octadecylamine and lead stearate is preferably (0.1-1):1, more preferably (0.1-0.6):1.

[0032] In the present invention, the organic halide salt preferably includes one or more of dibromotriphenylphosphine, octadecylamine iodide and oleylamine chloride, and more preferably dibromotriphenylphosphine. When there are multiple types of organic halide salts, the present invention has no special restrictions on the ratio of the different types of organic halide salts, and any ratio can be used. The present invention obtains perovskite quantum dot luminescent films of different luminescent colors by selecting different halide salts. Dibromotriphenylphosphine is the raw material of the green light film, and the green light is relatively stable.

[0033] In the present invention, the ultra-high organic molecular compound preferably includes one or more of polyolefin, polyolefin derivative, polyester, polyaldehyde, polyamide, polyol and polynitrile, more preferably polyolefin, most preferably polystyrene or polyethylene; the weight average molecular weight of the ultra-high organic molecular compound is preferably 10,000 to 1,000,000, more preferably 100,000 to 500,000. The present invention selects the ultra-high organic molecular compound with high processing performance as the forming matrix of the film, which can improve the ductility, flexibility and light transmittance of the composite film, and prepare a large-area, uniform, and high-luminous-efficiency composite film.

[0034] In the present invention, the molar ratio of cesium stearate, lead stearate and organic halide salt is preferably 1:1:(1-4), more preferably 1:1:(1-3); the total mass of cesium stearate, lead stearate and organic halide salt preferably accounts for 2-10% of the mass of the ultrahigh organic molecular compound, more preferably 3-5%.

[0035] In the present invention, the mixing is preferably carried out in an atmospheric environment; the mixing is preferably carried out under stirring conditions; the stirring rate is preferably 100 to 2000 rpm, more preferably 500 to 1000 rpm; the mixing time is preferably 3 to 5 min, more preferably 4 to 5 min.

[0036] After obtaining the perovskite precursor, the present invention melt-extrudes the perovskite precursor. During the melt-extrusion process, the perovskite precursor undergoes an ionization reaction to generate a perovskite quantum dot melt in situ inside a super-high organic molecular compound fluid, thereby obtaining a mixed melt system.

[0037] In the present invention, the temperature of the melt extrusion is preferably 100 to 250°C, more preferably 180 to 230°C.

[0038] In the present invention, the ionization reaction is preferably carried out under air atmosphere; the time of the ionization reaction is preferably 1 to 2 minutes, more preferably 2 minutes.

[0039] After obtaining the mixed molten system, the present invention sequentially casts, cools, stretches and rolls up the mixed molten system to obtain a perovskite quantum dot luminescent film.

[0040] In the present invention, the casting line speed is preferably 0.1 to 10 m / min, more preferably 3 to 5 m / min.

[0041] In the present invention, the preparation equipment of the perovskite quantum dot luminescent film is preferably a cast film forming system; the process of preparing the perovskite quantum dot luminescent film using the cast film forming system is preferably: the perovskite precursor is fed into the feed port of the cast film forming system, the perovskite precursor is subjected to twin-screw melt extrusion mixing at the melt extrusion station to undergo ionization reaction, and a perovskite quantum dot melt is generated in situ inside the ultrahigh molecular fluid to obtain a mixed melt system; the mixed melt system is extruded to a discharge extrusion die under the melt pressure of the heated and rotating twin screws, the extrusion die spreads the mixed melt system on a roller that continuously rotates at the cast film station for casting, and then cools on the roller flow channel, and is extended under the action of the traction force of the rotating roller and the extrusion force between adjacent rollers, and finally is wound up by a rotating reel at the winding station to obtain a perovskite quantum dot luminescent film.

[0042] In the present invention, the temperature of the twin screw is preferably 100-250°C, more preferably 180-230°C; the rotation rate of the twin screw is preferably 10-400rpm, more preferably 212rpm; the cooling temperature of the roller flow channel is preferably 30-80°C, more preferably 50-80°C; the rotation speed of the roller is 10-50rpm, more preferably 20-30rpm; the distance between adjacent rollers is 0.05-0.4mm, more preferably 0.2-0.4mm; the rotation speed of the reel is 30-50rpm, more preferably 30-40rpm.

[0043] In the present invention, the preparation speed of the perovskite quantum dot light-emitting film is preferably ≥8 m / min, more preferably 8 to 10 m / min.

[0044] The present invention also provides a perovskite quantum dot luminescent film prepared by the preparation method described in the above technical solution. The perovskite quantum dot luminescent film has a thickness of 0.1 to 1 mm and a luminescent efficiency of 40 to 90%.

[0045] In the present invention, the thickness of the perovskite quantum dot luminescent film is 0.1 to 1 mm, preferably 0.1 to 0.5 mm, and the luminous efficiency is 40 to 90%, preferably 80% to 90%.

[0046] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0047] Example 1

[0048] 1.04 g of cesium stearate, 1.93 g of lead stearate, 0.27 g of octadecylamine, 0.14 g of octadecanoic acid, 1.69 g of dibromotriphenylphosphine, and 100 g of polystyrene (weight average molecular weight of 100,000) were stirred in a mixer at 1000 rpm for 3 min in an atmospheric environment to obtain a perovskite precursor.

[0049] The perovskite precursor is put into the feeding port of the cast film forming system, and the perovskite precursor is melt-extruded and mixed by a twin-screw at 230° C. in the melt extrusion station to generate an ionization reaction for 2 minutes, and a perovskite quantum dot melt is generated in situ inside the polystyrene fluid to obtain a mixed melt system; the mixed melt system is extruded to a discharge extrusion die under the melt pressure of the twin-screw heating and rotating (230° C., 400 rpm), and the extrusion die spreads the mixed melt system on a roller that continuously rotates at the casting station for casting, and the linear speed of the casting is 8 m / min, and then cooled on the roller flow channel (60° C.), and extended under the action of the traction force of the roller rotation (20 rpm) and the extrusion force between the adjacent rollers with a distance of 0.2 mm, and finally rolled up at the winding station by a reel rotating at 35 rpm to obtain perovskite quantum dots (CsPbBr 3 )luminescent film.

[0050] Example 2

[0051] The difference from Example 1 is that the dibromotriphenylphosphine in Example 1 is replaced by octadecylamine iodide, and other conditions remain the same as in Example 1.

[0052] Example 3

[0053] The difference from Example 1 is that the dibromotriphenylphosphine in Example 1 is replaced by a mixture of dibromotriphenylphosphine and oleylamine chloride in a molar ratio of 1:1, and other conditions remain the same as in Example 1.

[0054] Example 4

[0055] The difference from Example 1 is that the rotation speed of the roller in Example 1 is replaced by 30 rpm, the distance between adjacent rollers is replaced by 0.1 mm, the rotation speed of the winding roll is replaced by 45 rpm, and other conditions remain the same as in Example 1.

[0056] Example 5

[0057] The difference from Example 1 is that the polystyrene in Example 1 is replaced by polyethylene, the melting temperature is replaced by 150° C., the temperature of the twin screw is replaced by 150° C., and other conditions remain the same as in Example 1.

[0058] Comparative Example 1

[0059] The difference from Example 1 is that the polystyrene in Example 1 is removed, and it is found that the adjusted scheme cannot obtain a quantum dot luminescent film, which indicates that the ultra-high organic molecular compound plays a vital supporting role therein.

[0060] Comparative Example 2

[0061] The same precursor formula as in Example 1 was used, but the casting process was not adopted. Instead, the film was sintered at the same temperature (230°C) for 1 hour and then hot-pressed at 230°C. It was found that although a luminescent film could be formed, the luminescence of the film was very uneven, and there were many dark spots inside the film where the precursor did not react completely. This shows that the melt extrusion of the twin-screw in the casting process plays an important role in the uniform growth of quantum dots.

[0062] Comparative Example 3

[0063] The same method as in Example 1 was adopted, except that the cooling temperature on the roller flow channel in Example 1 was adjusted to room temperature (25°C). It was found that the film after the adjustment hardened and tore rapidly due to the fast cooling speed after the casting, which was not conducive to the formation of a continuous film. This shows that cooling the film after casting also plays an important role in forming a high-quality luminous film.

[0064] Performance Testing

[0065] Figure 1 This is a photo of the perovskite quantum dot luminescent film prepared in Example 1. Figure 1 It can be seen that the prepared quantum dot luminescent film is uniform, continuous, has a large area, and exhibits good flexibility, indicating that the film-forming method can meet the requirements of continuous large-scale preparation of quantum dot luminescent films.

[0066] Figure 2 : is the fluorescence spectrum of the perovskite quantum dot luminescent film prepared in Example 1. Figure 2 It can be seen that the spectrum of the luminescent film in the green light band is pure and symmetrical, without other impurity peaks, and has a narrow half-peak width (25nm), indicating that the obtained quantum dot film has good luminescence properties and can meet the application needs of the display industry.

[0067] Figure 3 is the fluorescence spectrum of the perovskite quantum dot luminescent film prepared in Example 2. Figure 3 It can be seen that by changing the type of halide salt, the preparation of blue light-emitting film can be achieved, and the spectrum is pure, indicating that this method has good universality and compatibility.

[0068] Figure 4 : is the fluorescence spectrum of the perovskite quantum dot luminescent film prepared in Example 3. Figure 4 It can be seen that by changing the type of halide salt, the preparation of red light-emitting film can be achieved.

[0069] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for solvent-free continuous production of perovskite quantum dot luminescent film, It is characterized in that The following steps are involved: Cesium stearate, lead stearate, an organic halide salt, a surfactant and an ultra-high organic molecular compound are mixed to obtain a perovskite precursor; The perovskite precursor is melt-extruded, and during the melt-extrusion process, the perovskite precursor undergoes an ionization reaction to generate a perovskite quantum dot melt in situ inside the ultra-high organic molecular compound fluid to obtain a mixed melt system; The mixed molten system is sequentially cast, cooled, stretched and rolled up to obtain a perovskite quantum dot luminescent film.

2. The method according to claim 1, It is characterized in that The ultra-high organic molecular compound includes one or more of polyolefin, polyolefin derivative, polyester, polyaldehyde, polyamide, polyalcohol and polynitrile.

3. The method according to claim 1, It is characterized in that The temperature of the melt extrusion is 100-250°C.

4. The method according to claim 1, It is characterized in that The ion combination reaction is carried out in an air atmosphere; the time of the ion combination reaction is 1 to 2 minutes.

5. The preparation method according to claim 1, It is characterized in that The casting line speed is 0.1-10 m / min.

6. The method according to claim 1, It is characterized in that The organic halide salt includes one or more of dibromotriphenylphosphine, octadecylamine iodide and oleylamine chloride.

7. The method according to claim 1, It is characterized in that The surfactant comprises octadecylamine and octadecyl acid; the molar ratio of octadecylamine to octadecyl acid is (1-2):

1.

8. The method according to claim 1, It is characterized in that The total mass of the cesium stearate, lead stearate and organic halogen salt accounts for 2-10% of the mass of the ultra-high organic molecular compound.

9. The method according to claim 1, It is characterized in that The mixing is carried out under stirring conditions; the stirring rate is 100 to 2000 rpm; and the mixing time is 3 to 5 minutes.

10. The perovskite quantum dot luminescent film prepared by the method according to any one of claims 1 to 9, It is characterized in that The thickness of the perovskite quantum dot luminescent film is 0.1-1 mm, and the luminescent efficiency is 40-90%.

Images