An evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices

Abstract

This invention discloses an evaporation trap for the large-scale fabrication of quantum dot self-assembled superlattices, comprising: a boss located inside the evaporation trap for placing an evaporation substrate; a partition sleeved around the boss, with a first groove between the partition and the boss; and an outer wall of the evaporation trap, with a second groove between the inner side of the outer wall and the partition, the bottom of the second groove being no lower than the surface of the boss. The first and second grooves are each used independently to hold the evaporation solvent. A first glass cover is placed on top of the outer wall of the evaporation trap for primary sealing. This evaporation trap enables solvent evaporation within 12-48 hours, yielding quantum dot self-assembled superlattices with high microstructural regularity.

Description

Technical Field

[0001] This invention belongs to the field of quantum dot self-assembled superlattice preparation, specifically relating to an evaporation trap for large-scale preparation of quantum dot self-assembled superlattices. Background Technology

[0002] Nanocrystals with specific three-dimensional shapes, such as perovskite quantum dots, can be arranged in various forms, including face-to-face, in a periodic arrangement of hundreds of nanocrystals along three-dimensional directions to form regularly shaped aggregates such as large cubes, known as self-assembled "superlattices." These assemblies are cavity-containing microstructures with perfectly smooth surfaces and regular geometric structures, ensuring the formation of ideal whispering-gallery optical microcavities. Furthermore, in superlattice structures composed of nanocrystals, if the energy barriers between nanocrystals are thin, the coupling effect between the quantum wells of adjacent nanocrystals becomes significant, causing adjacent wave functions to superimpose and the corresponding energy levels to expand, forming energy bands. The position of the energy bands is related to the depth and width of the potential wells. Therefore, the individual nanocrystals in the superlattice structure couple with each other, producing many unique physicochemical properties not found in individual nanocrystals, and possessing broad application prospects.

[0003] Currently, the main methods for preparing quantum dot superlattices include: vacuum drying, solution method, external force driving method, and saturated solvent evaporation method, etc.

[0004] CN118931525A discloses a method for preparing quantum dot superlattice thin films. The method includes the following steps: S1, preparing a quantum dot solution and an ethylene glycol solution; S2, injecting the ethylene glycol solution into a dry mold; S3, spreading a layer of talc powder evenly on the surface of the ethylene glycol solution as a buffer layer; S4, adding the quantum dot solution dropwise onto the surface of the ethylene glycol solution, quickly covering it with a glass cover, and allowing the film on the liquid surface to dry; S5, after the film has dried, injecting an ethylenediamine solution into a corner of the mold for ligand exchange; S6, after the ligand exchange is completed, removing the final obtained film and drying it. This preparation method, by first spreading a layer of talc powder as a buffer layer on the liquid surface before adding the quantum dot solution at the gas-liquid interface, effectively isolates the interaction between the quantum dot film and the mold, decoupling the film preparation process from the mold. This effectively alleviates the internal stress generated during the evaporation and assembly of the quantum dot solution, improving the repeatability and uniformity of the final superlattice thin film, and has broad application prospects. However, the solution evaporation rate disclosed in the above patent cannot be controlled, so the control over lattice uniformity and size needs to be further improved.

[0005] Although there are various methods for superlattice fabrication, current methods still suffer from problems such as long preparation cycles, low superlattice quality, and poor controllability. Therefore, developing a method for large-scale fabrication of high-quality superlattices is of great significance for the future applications of superlattices. As one of the more widely used superlattice fabrication methods, the saturated solvent evaporation method is extensively applied. Its key lies in precisely controlling the evaporation rate during superlattice self-assembly and providing a stable external environment.

[0006] However, the evaporation environment provided by the current saturated solvent evaporation method is relatively rough (generally prepared in beakers or petri dishes), especially its poor control over the evaporation rate, which is obviously detrimental to the large-scale controllable preparation of superlattice microcavities. Summary of the Invention

[0007] This invention provides an evaporation trap for the large-scale preparation of quantum dot self-assembled superlattices. The evaporation trap enables solvent evaporation within 12-48 hours, resulting in quantum dot self-assembled superlattices with high microstructure regularity.

[0008] This invention provides an evaporation trap for the large-scale fabrication of quantum dot self-assembled superlattices, comprising:

[0009] A boss located inside the evaporation trap, the boss being used to place the evaporation substrate;

[0010] A partition is sleeved around the protrusion, and a first groove is provided between the partition and the protrusion;

[0011] The outer wall of the evaporator trap has a second groove between its inner side and the partition plate. The bottom of the second groove is not lower than the top of the boss. The first groove and the second groove are used to place the evaporating solvent separately. A first glass cover plate is placed on the top of the outer wall of the evaporator trap for primary sealing.

[0012] Preferably, the outer wall of the evaporation trap is further provided with a step, and a second glass cover is placed at the step for secondary sealing.

[0013] The present invention forms a step-by-step seal between the second glass cover plate set on the step and the first glass cover plate, thereby creating a saturated vapor environment inside the vapor trap, reducing vapor escape, and facilitating the control of the size of the self-assembled crystal.

[0014] Preferably, the second glass cover is located below the first glass cover.

[0015] Preferably, the top height of the partition is lower than the height of the step.

[0016] More preferably, a third glass cover is placed on top of the partition, the third glass cover being located below the second glass cover for a three-level seal.

[0017] This invention forms a hierarchical sealing structure by fitting three glass cover plates together. By adjusting the number of sealing layers of the glass cover plates and the amount of evaporated solvent in the second groove, this invention can control the duration of the saturated solvent vapor atmosphere, thereby providing a stable saturated vapor environment for the self-assembly of quantum dots into a superlattice and achieving precise control over the self-assembled superlattice.

[0018] The third glass seal can slow down the evaporation rate of the quantum dot solution. The vapor atmosphere after the third glass seal can also be maintained by a small amount of solvent in the quantum dot solution. The vapor after the solvent in the second groove evaporates mainly serves as the vapor escaping the evaporation trap, thus ensuring that the solvent in the solution can be maintained before the additional solvent evaporates.

[0019] Preferably, the boss is located at the center of the evaporation trap.

[0020] Preferably, the top of the boss is a horizontal plane.

[0021] Preferably, the evaporation trap is a sealable cube or cylinder, and the material of the evaporation trap is plastic or metal, wherein the plastic is Teflon.

[0022] Preferably, during the large-scale preparation of quantum dot self-assembled superlattices, the external temperature of the evaporation trap is 10-70°C, 20-60 μL of an assembly trap quantum dot solution with a concentration of 5-100 mg / mL is dropped onto the evaporation substrate, and a maximum of 0.3 mL of evaporation solvent is placed in the second groove.

[0023] Preferably, the assembled trap quantum dot solution is CsPbX3 or Cd-based quantum dots, and the evaporation solvent is toluene or n-hexane.

[0024] The perovskite quantum dot superlattice microcavities prepared based on the above-mentioned evaporation traps are uniformly distributed on the whole assembly substrate, and their size can be precisely adjusted between hundreds of nanometers and tens of micrometers by controlling the above parameters. At the same time, the superlattice microcavities have high microscopic quality, that is, regular morphology, orderly arrangement and relatively smooth surface, which provides a good structural basis for their optical applications.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The bottom height of the second groove provided by the present invention is greater than or equal to the top height of the boss, thereby ensuring that the evaporating solvent in the second groove evaporates earlier than the assembly well quantum dot solution on the boss, so that the assembly well quantum dot solution is maintained for a longer time and is adjustable, realizing self-assembly with controllable time, and thus obtaining a self-assembled crystal with uniform distribution and adjustable size. Attached Figure Description

[0027] Figure 1 A three-dimensional structural diagram of the evaporation trap provided in a specific embodiment of the present invention;

[0028] Figure 2 A physical diagram of the evaporation trap provided for a specific embodiment of the present invention;

[0029] Figure 3 Three-view drawings of an evaporation trap provided for a specific embodiment of the present invention;

[0030] Figure 4 Optical microscope and SEM images of CsPbBr3 perovskite quantum dots assembled and prepared using the evaporation trap provided in Embodiment 1 of the present invention;

[0031] Figure 5 SEM images of different-sized superlattices of CsPbBr3 perovskite quantum dots assembled and prepared using the evaporation trap provided in Embodiment 2 of the present invention, wherein... Figure 5 a is the SEM image of the 2µm superlattice. Figure 5 b is the SEM image of the 5µm superlattice. Figure 5 c is the SEM image of a 10µm superlattice;

[0032] Figure 6 Confocal microscopy image of a 5µm CsPbBr3 perovskite quantum dot self-assembled superlattice microcavity prepared using the evaporation trap provided in Embodiment 3 of the present invention.

[0033] Figure 7 The diagram shows the single-mode and multi-mode laser output under 405nm femtosecond laser excitation provided in Embodiment 3 of the present invention.

[0034] Among them, there is a boss 1, a partition 2, an outer wall of the evaporator trap 3, a step 31, a first groove 4, and a second groove 5. Detailed Implementation

[0035] This invention specifically describes an evaporation trap for the large-scale fabrication of high-quality perovskite quantum dot superlattices using a saturated solvent evaporation method. By precisely and controllably adjusting the evaporation time of the saturated solvent within 12-48 hours, the controllability and microstructural regularity of the fabricated superlattice microcavities are further improved while achieving large-scale fabrication. Ultimately, the optical performance of these microcavities is further enhanced, which has significant implications for their application and research in micro / nano lasers and quantum light sources.

[0036] A specific embodiment of the present invention provides an evaporation trap for the large-scale fabrication of quantum dot self-assembled superlattices, such as... Figure 1 As shown, the device includes a boss 1, a partition 2, and an outer wall 3 of the evaporation trap. The boss 1 is located at the center of the evaporation trap, and the evaporation substrate is placed on the boss 1. The partition 2 provided in this specific embodiment is sleeved around the boss 1. A first groove 4 is provided between the partition 2 and the boss 1. A second groove 5, concentric with the first groove 4, is provided between the partition 2 and the outer wall 3 of the evaporation trap. The second groove 5 is a solvent addition groove, in which evaporation solvent is added. The bottom of the second groove 5 is on the same plane as the top of the boss 1, or higher than the surface of the boss 1, thereby ensuring that the evaporation solvent in the second groove evaporates earlier than the quantum dot solution in the evaporation trap on the evaporation substrate, prolonging the saturated vapor holding time, so that the quantum dot crystals can be uniformly distributed on the substrate.

[0037] The second groove 5 provided in the specific embodiment of the present invention is a U-shaped groove. The two side walls of the U-shaped groove are the outer side of the partition 2 and the inner side of the outer wall 3 of the evaporator. At the bottom of the U-shaped groove, a horizontal plane located between the outer wall of the evaporator and the partition forms the bottom wall of the second groove. The horizontal plane at the top of the boss forms the top wall of the boss. Specifically, the bottom wall of the second groove is not lower than the top wall of the boss. The height of the side wall of the partition 2 is lower than the height of the outer wall of the evaporator, that is, the top height of the partition 2 is lower than the height of the outer wall of the evaporator. Therefore, a third glass cover can be placed on the top of the partition 2. The third glass cover is closest to the boss and is used for three-level encapsulation.

[0038] The outer wall 3 of the evaporator provided in the specific embodiment of the present invention is further provided with a step 31, at which a second glass cover plate is placed for secondary sealing. A first glass cover plate for primary sealing is placed on the top of the outer wall 3 of the evaporator. The third glass cover plate is located below the second glass cover plate, and the second glass cover plate is located below the first glass cover plate. The specific embodiment of the present invention achieves the use of up to three layers of transparent glass cover plates through the first, second and third glass cover plates, which can realize step-by-step sealing from the inside of the evaporator where the assembly substrate is located to the edge of the evaporator, thereby facilitating the formation of a step-by-step sealed saturated solvent vapor environment. By adjusting the number of glass cover plate layers, the amount of solvent vapor escaping to the outside can be regulated, thereby controlling the maintenance time of saturated solvent vapor.

[0039] In a specific embodiment of the present invention, the boss is located at the center of the evaporation trap, and the surface of the boss is a horizontal plane.

[0040] The evaporation trap provided in the specific embodiments of the present invention is a sealable cube or cylinder, and the material of the evaporation trap is plastic or metal, wherein the plastic is Teflon.

[0041] In one specific embodiment, such as Figure 3 As shown in the three views, this embodiment provides an evaporation trap, which is cubic or cylindrical in shape and made of plastic or metal. Its side dimensions are 20mm (length) * 20mm (width) * 20mm (height). Two recesses are carved out in the middle, namely the first recess and the second recess, separated by a partition. Inside the evaporation trap, in the center, is a raised platform 8mm (length) * 8mm (width) * 5mm (height) high with a smooth surface. The second recess is a solvent addition tank, into which evaporation solvent can be added to prolong the saturated vapor holding time. The lowest plane of this solvent addition tank and the plane of the central raised platform are on the same plane. This design ensures that the solvent in the solvent addition tank evaporates before the evaporation substrate. The height of the solvent addition tank near the center is 17mm, less than the height of the evaporation trap. A glass cover can be placed on top of this side. When assembling the superlattice, glass covers can also be used at the top of the evaporation trap and at the first step 2mm below it. Ultimately, by using up to three layers of transparent glass covers, a step-by-step sealing can be achieved from the interior of the evaporation trap containing the assembly substrate to the entire evaporation trap, thus forming a step-by-step sealed saturated solvent vapor environment. Furthermore, by adjusting parameters such as the number of sealing layers of the glass covers, the amount of additional solvent added, the ambient temperature of the assembly trap, and the amount of quantum dot solution added, this assembly trap can maintain a saturated solvent vapor atmosphere between 12 and 48 hours. This provides a stable saturated vapor environment for the self-assembly of quantum dots into a superlattice, enabling precise control over the self-assembled superlattice, such as... Figure 2 A physical image of the evaporation trap provided for this example.

[0042] The saturated solvent evaporation method for evaporation traps provided in this embodiment is simple to operate, highly efficient, controllable, and reproducible. It enables precise control of the superlattice size, allowing for dense and uniform superlattice arrangement across a single substrate material, resulting in a microscopically regular and long-range ordered superlattice morphology. Under suitable light source excitation, the superlattice microcavities prepared by this method can simultaneously serve as gain media and resonant cavities, successfully generating laser light and demonstrating broad application prospects in micro / nano lasers and other fields.

[0043] The structural parameters of the evaporation trap provided in this embodiment are as follows:

[0044] The evaporation trap provided in the specific embodiment of the present invention is a cube with side dimensions of 20mm (length) * 20mm (width) * 20mm (height). A first groove with dimensions of 11.5mm (length) * 11.5mm (width) * 15mm (depth) is carved out inside, and the groove width is 1.75mm.

[0045] The evaporator provided in this embodiment has a boss with a height of 8mm (length) * 8mm (width) * 5mm (height) in the middle of its interior. The surface of the boss is flat.

[0046] In this embodiment, an additional solvent-adding groove of 16mm (length) * 16mm (width) * 10mm (depth) is provided outside the first groove, namely the second groove. The first groove and the second groove are concentric grooves and are separated by a partition. Up to 0.3ml of evaporating solvent can be added inside the second groove. The lowest plane of the second groove and the plane of the boss are at the same height, and the height of the second groove near the middle side is 17mm, which is less than the height of the evaporation trap. A third glass cover can be placed on the top of this side.

[0047] In this embodiment, a step is also provided on the outer wall of the evaporator. The step is located 2 mm below the top of the outer wall of the evaporator. A second glass cover is placed at the step, and a first glass cover is placed at the top of the outer wall of the evaporator.

[0048] In a specific embodiment of the present invention, during the assembly of the superlattice, a cleaned and dried assembly substrate is placed into a custom-designed Teflon evaporation trap (as shown in the attached figure). Figure 2 As shown, an appropriate amount of the prepared quantum dot solution, such as CsPbBr3 quantum dot solution, is dropped onto the substrate using a pipette. The evaporation trap is placed on a horizontal, stable, and vibration-free evaporation platform, and a transparent three-layer glass plate is used to cover the evaporation trap. The solvent is then slowly evaporated at a specific temperature. Observation through the glass cover shows that a high-quality superlattice microcavity structure of a specific size range is assembled on the substrate after the solvent has evaporated completely.

[0049] In Example 1, this example illustrates how to prepare monodisperse CsPbBr3 perovskite quantum dots based on the hot-injection method and a customized Teflon evaporation trap to achieve the large-scale preparation of CsPbBr3 perovskite colloidal quantum dot superlattice microcavities. The implementation process and preparation method are as follows:

[0050] (1) First, weigh 200 mg of cesium carbonate powder, 7.5 ml of octadecene and 0.88 ml of oleic acid ligand, add them to a three-necked flask and mix them evenly. Heat the mixture to 120 °C under a nitrogen atmosphere and stir continuously until completely dissolved. Then lower the temperature of the solution to 100 °C for later use as a cesium oleate precursor.

[0051] (2) Weigh 70 mg of lead bromide powder, 5 ml of octadecene, 0.5 ml of oleic acid and 0.5 ml of oleylamine ligand, add them to a three-necked flask and mix them evenly. Vacuum the flask to remove water and oxygen, then introduce nitrogen gas. Stir and heat to 120°C under a nitrogen atmosphere and keep for about 1 hour to obtain a clear, homogeneous solution without solids, i.e., the reaction solution.

[0052] (3) The reaction solution was heated and stabilized at 175°C, and then 0.5 ml of the precursor stock solution was injected into the reaction solution through a long-tipped glass syringe. After reacting for 5 seconds, the mixed solution was cooled to room temperature using an ice-water bath;

[0053] (4) The crude solution obtained above was centrifuged at 12100 r / min for 5 min. The supernatant was then discarded. 2 ml of n-hexane was added to the precipitate and vortexed to dissolve it completely. After dissolution, the solution was centrifuged again under the same conditions. The unreacted salt precipitate was discarded. The supernatant was taken and an appropriate amount of the antisolvent methyl acetate was added. The solution was centrifuged at the same speed for 3 min. Finally, the precipitate was dissolved in a certain amount of toluene to obtain a CsPbBr3 quantum dot solution with a concentration of 15 mg / ml and stored in a brown light-proof bottle.

[0054] (5) Place the clean 10×10mm single-crystal Si substrate into a custom-made Teflon evaporation trap (as shown in the attached diagram). Figure 2 As shown, 30 μL of the prepared CsPbBr3 quantum dot solution was carefully drop-coated onto a single-crystal silicon substrate using a pipette, without adding any additional toluene solvent to the evaporation trap. The evaporation trap was placed on a horizontal, stable, and vibration-free evaporation platform, and a transparent glass plate was used to cover the evaporation trap to create a closed space with a saturated toluene vapor atmosphere. At room temperature (25°C), the toluene solvent in the quantum dot solution slowly evaporated for approximately 12 hours. After the solvent evaporated completely, a high-quality superlattice microcavity structure of a specific size was assembled on the substrate on a large scale.

[0055] In this embodiment, the morphology of the CsPbBr3 perovskite quantum dots and self-assembled superlattice microcavities prepared on a large scale were observed using optical microscopy and SEM. Figure 4 As shown, the assembled perovskite quantum dot superlattice forms a uniform green thin film on the silicon substrate. Under an optical microscope, the superlattice exhibits a sharp-edged square geometry. Due to the coffee ring effect, the superlattice at the edges is larger, averaging around 6 μm, while the superlattice at the center is slightly smaller, averaging around 4 μm.

[0056] The fabrication method provided in this embodiment enables the large-scale, controllable fabrication of self-assembled quantum dot superlattices, such as the large-scale, controllable fabrication of CsPbBr3 perovskite colloidal quantum dot superlattice microcavities in the above embodiment, ranging from 1 to 10 μm. The fabrication process is simple, low-cost, and highly reproducible. The fabricated superlattice microcavities exhibit high order and regular geometric morphology, and can simultaneously serve as gain media and resonant cavities, enabling high-quality, stable micro / nano laser output in whispering-gallery mode in batches, thus showing broad application prospects.

[0057] In Example 2, this example illustrates how to prepare monodisperse CsPbBr3 perovskite quantum dots based on a hot-injection method and a customized Teflon evaporation trap to achieve controllable preparation of CsPbBr3 perovskite colloidal quantum dot superlattice microcavities with dimensions of 1-10 μm. The implementation process and preparation method are as follows:

[0058] For specific experimental procedures, please refer to Example 1. The difference lies in controlling the amount of quantum dot solution added to the assembly substrate (20-60 μL), the ambient temperature of the evaporation trap (25-70 °C), and the amount of additional toluene solvent added (0-0.3 mL) to maintain the solvent-saturated atmosphere for 12-48 hours. This allows for control of the evaporation rate of the saturated solvent within the assembly trap, thereby controlling the size of the assembled superlattice. Based on the control of the toluene solvent evaporation rate, we can achieve fine adjustment of the CsPbBr3 perovskite quantum dot superlattice size within the range of 1-10 μm. Table 1 below lists the assembly conditions for superlattices of 2 μm, 5 μm, and 10 μm sizes. Optical microscopy and SEM images of the size control effect are shown below. Figure 5 a- Figure 5 As shown in c, other superlattices with sizes of 1-10 μm can be obtained by fine-tuning the above parameters.

[0059] Table 1 shows the assembly conditions for the three superlattice sizes of 2µm, 5µm, and 10µm.

[0060] Superlattice size quantum dot concentration Assembly temperature Quantum dot solution addition amount Additional toluene solvent addition 2μm 5mg / ml 25℃ 30μl 0ml 5μm 5mg / ml 25℃ 30μl 0.3ml 10μm 15mg / ml 25℃ 30μl 0.3ml

[0061] In general, to a certain extent, the size of the assembled superlattice is positively correlated with the concentration of the quantum dot solution and the amount of additional toluene solvent added. Generally, to a certain extent, the lower the saturated solvent evaporation rate, the higher the quality of the assembled superlattice and the better its structural regularity.

[0062] In Example 3, this example illustrates how to achieve single-mode and multi-mode micro / nano laser output from a CsPbBr3 perovskite quantum dot superlattice microcavity (taking the 5µm superlattice prepared above as an example) fabricated on a large scale using CsPbBr3 perovskite quantum dots prepared by the hot-injection method and a customized Teflon evaporation trap. The implementation method is as follows:

[0063] The experimental equipment used in this example is an ultrafast transient spectrometer. The specific experimental steps are as follows: First, place the single-crystal silicon wafer with the assembled superlattice sample on the sample stage of the micro-fluorescence spectrometer. Adjust the height of the sample stage, select a 50x lens, and locate the square CsPbBr3 superlattice structure sample under the microscope, as shown below. Figure 6 As shown in the figure. Then, the 405nm laser from the femtosecond laser was introduced into the spectrometer. After adjusting the microscope lens and focusing the spot, spectral detection was performed. The fluorescence spectrum of the sample could be obtained under low-power pumping. Next, by gradually increasing the excitation power, lasing output of single-mode and multi-mode lasers could be obtained in the superlattice microcavity. The experimental results are shown in the figure. Figure 7 As shown in figures a and b, the sharp, narrow peak in the spectrum represents a single laser mode. This demonstrates that the CsPbBr3 perovskite quantum dot self-assembled superlattice sample prepared based on the evaporation trap can be used as a laser microcavity under pump light excitation, generating lasing. The appearance of multiple laser peaks indicates that the superlattice prepared based on the evaporation trap produces laser output in different modes, further demonstrating the excellent properties of the superlattice prepared by this method as a laser resonator.

Claims

1. An evaporation trap for the large-scale fabrication of quantum dot self-assembled superlattices, characterized in that, include: A boss located inside the evaporation trap, the boss being used to place the evaporation substrate; A partition is sleeved around the protrusion, and a first groove is provided between the partition and the protrusion; The outer wall of the evaporator trap has a second groove between its inner side and the partition plate. The bottom of the second groove is not lower than the top of the boss. The first groove and the second groove are used to place the evaporating solvent separately. A first glass cover plate is placed on the top of the outer wall of the evaporator trap.

2. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 1, characterized in that, The outer wall of the evaporation trap is also provided with a step, and a second glass cover is placed at the step.

3. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 2, characterized in that, The second glass cover is located below the first glass cover.

4. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 3, characterized in that, The top of the partition is lower than the height of the step.

5. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 4, characterized in that, A third glass cover is placed on top of the partition, and the third glass cover is located below the second glass cover.

6. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 1, characterized in that, The boss is located at the center of the evaporation trap.

7. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 1, characterized in that, The top of the boss is a horizontal plane.

8. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 1, characterized in that, The evaporation trap is a sealable cube or cylinder, and the material of the evaporation trap is plastic or metal, wherein the plastic is Teflon.

9. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 1, characterized in that, In the large-scale preparation of quantum dot self-assembled superlattices, the external temperature of the evaporation trap is 10-70℃, 20-60ul of assembly trap quantum dot solution with a concentration of 5-100mg / ml is dropped onto the evaporation substrate, and a maximum of 0.3ml of evaporation solvent is placed in the second groove.

10. The evaporation trap for large-scale fabrication of quantum dot self-assembled superlattices according to claim 1, characterized in that, The assembled trap quantum dot solution is CsPbX3 or Cd-based quantum dots, and the evaporation solvent is toluene or n-hexane.

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