Method for encoding and storing quantum dot information with optimized spectral consistency, quantum dot ink, preparation method and use thereof

Abstract

The present invention relates to a method for encoding and storing quantum dot information with optimized spectral consistency, quantum dot ink, and a preparation method and use thereof. The system / method for encoding and storing quantum dot spectral information with optimized spectral consistency of the present invention includes printing quantum dot ink into a film, thereby encoding and storing spectral information. The quantum dot ink includes quantum dots, water, and a water-soluble organic solvent, wherein the boiling point and viscosity of the water-soluble organic solvent are higher than those of water, and the volume ratio between water and the water-soluble organic solvent is 60:40 to 20:80. The volatilization process of the quantum dot ink of the present invention after printing can avoid the coffee ring effect, so that it can form a smooth film, and thus can achieve better spectral consistency.

Description

Technical Field

[0001] The present invention relates to a method for encoding and storing quantum dot spectral information with optimized spectral consistency, quantum dot ink, a preparation method thereof, and use of quantum dot ink for encoding and storing quantum dot spectral information. Background Art

[0002] In recent years, people have paid more and more attention to the anti-counterfeiting and encryption of information storage. Coding technology is an effective means to encrypt stored information to prevent information leakage and forgery. Various geometric patterns, chemical patterns, characteristic spectra and other unique chemical or photoelectric signals provide objects for encoding. Among them, encoding based on characteristic spectra has attracted increasing attention due to its ability to achieve strong anti-counterfeiting and confidentiality.

[0003] Quantum dots can be used for information encoding and information storage due to their excellent optical properties, and can be applied to the fields of anti-counterfeiting and information encryption. Patent document 1 discloses an amphiphilic graphene quantum dot material and a fluorescent coding anti-counterfeiting ink based thereon, which adjusts the concentration of the graphene quantum dot material and the composition of the mixed solvent to make the ink reflect different fluorescent colors. This fluorescent coding is difficult to imitate by other fluorescent materials except for the manufacturer, thus improving the security of the anti-counterfeiting mark. In addition, patent document 2 discloses a printable fluorescent anti-counterfeiting ink, which is obtained by adding a hydrophilic modifier aqueous solution to an organic solution of oil-soluble quantum dots, and then adding a mixed solvent of water, ethanol and ethylene glycol to the quantum dot aqueous solution and adjusting the pH value to obtain an anti-counterfeiting ink.

[0004] Although the above documents involve quantum dot anti-counterfeiting ink, none of them involve quantum dots for information encoding and storage methods. The inventors used quantum dots to study the optical data encoding and storage based on spectral channels and found that there would be spectral consistency error interference in the data storage and reading process, resulting in deviations from the ideal design spectral value, causing the data recognition accuracy of the spectral information encoding method to be greatly affected by the error.

[0005] References:

[0006] Patent document 1: CN110615428A

[0007] Patent document 2: CN112175449A Summary of the invention

[0008] Problem that the invention aims to solve

[0009] Because the spectral design can be done by mixing materials, the consistency of the ink output in different spaces can be well controlled through inkjet printing technology (with completely consistent printing conditions) (same output volume and same area and thickness after film formation), and the corresponding quantum dot material can be printed at a specific location to produce the required spectral curve at that location. In order to ensure the spatial consistency of the spectral properties of the material (that is, the spectra at different measurement locations in the storage area should be consistent, such as Figure 1 As shown in the figure, the spectral consistency of any two storage points with the same spectral channel components, and the spectral consistency within the storage site area, that is, the material is evenly dispersed and highly consistent within the storage site, and the printed film spectrum needs to be consistent with the theoretically designed spectrum as much as possible. However, as mentioned above, errors in the data storage and reading process lead to deviations from the ideal designed spectral value.

[0010] No research has been found in the prior art specifically for reducing the spectral consistency error for this spectral application scenario. Therefore, the purpose of the present invention is to provide a method for encoding and storing quantum dot spectral information that can reduce the influence of spectral consistency error, make the measured spectrum close to the theoretical design value, and print the spectrum of each point with spatial uniformity. Another purpose of the present invention is to provide quantum dot ink and its preparation method, as well as the use of quantum dot ink for quantum dot spectral information encoding and storage.

[0011] Solutions for solving problems

[0012] In the present invention, by adjusting and optimizing the boiling point and surface tension of the solvent in the quantum dot solution, adding a specific water-soluble organic solvent to the aqueous phase quantum dot solution and adjusting the ratio of the two, the volatilization process of the ink after printing can be controlled, so that the quantum dots will not migrate over a large range during the solvent volatilization process, avoiding the coffee ring effect that occurs when the pure quantum dot solution is printed, so that it can form a flat film, and thus can achieve better spectral consistency.

[0013] [1] Specifically, the present invention provides a method for encoding and storing quantum dot spectral information with optimized spectral consistency, which comprises printing quantum dot ink into a film to encode and store spectral information,

[0014] The quantum dot ink comprises quantum dots, water and a water-soluble organic solvent, wherein the boiling point and viscosity of the water-soluble organic solvent are higher than those of water, and the volume ratio of water to the water-soluble organic solvent is 60:40 to 20:80.

[0015] [2] The method according to the above [1], wherein the total concentration of the quantum dots is expressed by an optical density value of OD=3~10, preferably 5~8; and / or the viscosity of the quantum dot ink is 5~15mPa·s; and / or the content of the water-soluble organic solvent is 20% to 60% by volume, preferably 25% to 50% by volume relative to the total amount of the quantum dots, water and the water-soluble organic solvent.

[0016] [3] The method according to [1] or [2] above, wherein the boiling point of the water-soluble organic solvent is 150 to 300°C, and the viscosity at 20°C is 25 to 100 mPa·s; and / or the surface tension of the quantum dot ink is 40 to 60 mN·m -1 .

[0017] [4] According to the method described in any one of [1] to [3] above, the water-soluble organic solvent is selected from one or more of ethylene glycol, propylene glycol, butylene glycol and glycerol.

[0018] [5] The method according to any one of [1] to [4] above, wherein the quantum dots are quantum dots of Group II-VI compounds selected from CdS, CdSe, CdTe, ZnS, ZnSe, PbS, and PbSe; quantum dots of Group III-V compounds selected from InP, GaP, GaN, and AlN; quantum dots of core-shell structure materials selected from CdS / ZnS, CdSe / CdS, CdSe / ZnS, CdSe / CdS / ZnS, CdTe / CdS, CdTe / CdS / ZnS, ZnSe / ZnS, InP / ZnSe, InP / ZnS, InP / ZnSe / ZnS, InP / ZnSe / ZnS, and InP / GaP / ZnS; perovskite quantum dots; quantum dots of precious metals selected from Au, Ag, and Pt; or carbon quantum dots.

[0019] [6] According to the method described in any one of [1] to [5] above, the quantum dot ink also includes an additive, the additive includes one or more of polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, and polyacrylic acid; and / or the content of the additive is 4 volume % to 10 volume % relative to the total amount of the quantum dots, water and the water-soluble organic solvent.

[0020] [7] The method according to any one of [1] to [6] above, wherein the volume ratio of water to the water-soluble organic solvent is 55:45 to 30:70, preferably 55:45 to 40:60.

[0021] [8] A quantum dot ink used in the method for encoding and storing quantum dot spectral information with optimized spectral consistency as described in any one of [1]-[7] above.

[0022] [9] A method for preparing the quantum dot ink described in [8] above, comprising the following steps: adding a water-soluble organic solvent having a boiling point and a viscosity higher than that of water and an optional additive to an aqueous solution of quantum dots, thereby obtaining the quantum dot ink.

[0023]

[10] A use of the quantum dot ink described in [8] above for encoding and storing quantum dot spectral information.

[0024] Effects of the Invention

[0025] The above technical solution of the present invention has the following beneficial effects:

[0026] 1) Reduce the impact of spectral consistency errors, improve spectral recognition accuracy, and reduce data reading bit error rate;

[0027] 2) Ensure the consistency of the spectral properties of quantum dots in space, the spectral consistency of any two storage points with the same spectral channel components, and the spectral consistency within the storage site area, that is, the quantum dots are evenly dispersed and highly consistent within the storage site;

[0028] 3) The spectral properties of quantum dots can remain stable during the storage time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is an explanatory diagram showing the requirement for spatial uniformity of quantum dot spectra.

[0030] Figure 2 is a diagram showing the change in morphology of a film printed by quantum dot ink as the ratio of water to ethylene glycol is changed.

[0031] Figure 3 Graph showing the effect of different proportions of ethylene glycol on the measurement error of the quantum dot spectrum after film formation.

[0032] Figure 4 Graph showing the effect of different amounts of additives on the measurement error of the quantum dot spectrum after film formation.

[0033] Figure 5 The figure shows the spectral stability monitoring of quantum dot films printed with quantum dot ink stored under different conditions.

[0034] Figure 6 1 is a diagram showing the influence of the error in spectrum measurement on the accuracy of information reading and recognition, through simulation analysis. DETAILED DESCRIPTION

[0035] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0036] In this specification, unless otherwise specified, the word "multiple" in "multiple", "multiple", "plurality", etc. means a numerical value of 2 or more.

[0037] In the present specification, the term “substantially”, “substantially” or “essentially” means that the error is less than 5%, less than 3% or less than 1% compared with the relevant perfect standard or theoretical standard.

[0038] In this specification, unless otherwise specified, "ratio" means volume ratio.

[0039] In this specification, unless otherwise specified, "%" means mass percentage.

[0040] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0041] In the present specification, "optional" or "optionally" means that the event or situation described below may or may not occur, and the description includes cases where the event occurs and cases where it does not occur.

[0042] In this specification, the references to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0043] In this specification, the "boiling point" refers to the boiling point under normal pressure.

[0044] In this specification, if "room temperature" or "normal temperature" appears, the temperature may generally be 10-40°C.

[0045] <First aspect>

[0046] The quantum dot ink of the present invention can be used for the preparation of spectral information encoding and storage. The first aspect of the present invention relates to a method for quantum dot information encoding and storage with optimized spectral consistency, which comprises printing the quantum dot ink into a film to perform spectral information encoding and storage.

[0047] Specifically, the method of using quantum dot ink to encode and store spectral information may include: determining the number of spectral channels and the spectral channel gradient according to the requirements of the information to be stored; the number of spectral channels corresponds to the number of the information to be stored, the spectral channel gradient corresponds to the content of the information to be stored, and the spectral channel gradient represents the weight of each spectral channel; determining the type and concentration of the quantum dot ink material of the storage unit according to the number of spectral channels and the spectral channel gradient, and in one case the concentration of the quantum dot ink may include a concentration of 0; a storage unit with spectral information encoding and storage capabilities can be obtained by printing quantum dot materials; and then a storage medium is obtained.

[0048] When reading data, the spectral information stored in the storage unit can be obtained by irradiating the storage unit with incident light, and the spectral channel and gradient information contained in the spectral information can be obtained through analysis, thereby obtaining the specific stored content.

[0049] In the present invention, there is no particular limitation on the specific printing film-forming method, and conventional printing methods in the art can be used.

[0050] The quantum dot ink of the present invention comprises quantum dots, water and a water-soluble organic solvent. In the present invention, the viscosity and surface tension of the quantum dot solution are adjusted and optimized, so as to better control the volatilization process of the ink after printing, so that the quantum dots will not migrate in a large range during the solvent volatilization process, and the coffee ring effect that occurs when the pure quantum dot solution is printed is avoided, so that the ink can form a flat film, thereby achieving better spectral consistency.

[0051] quantum dots

[0052] In the present invention, there is no particular limitation on the type of quantum dots, and quantum dots commonly used in the field of spectral information encoding and storage can be used. As quantum dots suitable for the present invention, some specific embodiments may include:

[0053] II-VI semiconductor quantum dots such as cadmium sulfide (CdS), cadmium tin (CdSe), cadmium telluride (CdTe) and zinc sulfide (Zns);

[0054] IV-VI semiconductor quantum dots such as lead sulfide (PbS) and lead selenide (PbSe);

[0055] III-V semiconductor quantum dots such as indium phosphide (InP) and indium arsenide (InAs);

[0056] Core-shell quantum dots such as CdS / ZnS, CdSe / CdS, CdSe / ZnS, CdSe / CdS / ZnS, CdTe / CdS, CdTe / CdS / ZnS, ZnSe / ZnS, InP / ZnSe, InP / ZnS, InP / ZnSe / ZnS, InP / GaP / ZnS;

[0057] Noble metal single substances such as Au, Ag and other quantum dots; and

[0058] One or more of quantum dots based on perovskite structure and carbon quantum dots.

[0059] In some preferred embodiments of the present invention, the quantum dots of the present invention can be selected from one or a mixture of various semiconductor quantum dots.

[0060] In the present invention, there is no particular limitation on the method for synthesizing quantum dots, and conventional methods in the art can be used. In some specific embodiments of the present invention, the quantum dots suitable for the present invention can be selected from colloidal quantum dots. For such a method for synthesizing quantum dots, typically, the raw materials can be first dissolved in an organic solvent or a ligand to form a precursor, and then mixed under heating conditions to form quantum dots through a chemical reaction.

[0061] There is no particular limitation on the particle size of the quantum dots of the present invention. In some specific embodiments of the present invention, the particle size may be 1 to 100 nm. Preferably, the particle size may range from 2 to 70 nm, more preferably from 2 to 60 nm, further preferably from 2 to 50 nm, and further preferably from 3 to 30 nm, 3 to 20 nm or 3 to 10 nm.

[0062] In the quantum dot ink of the present invention, the total concentration of quantum dots is not particularly limited and can be adjusted based on the desired thickness of the film. Usually, the total concentration of quantum dots is OD=3-10, preferably 5-8. "OD" in this article is the optical density value (Optical density), which is generally measured by a commercial UV-visible spectrophotometer. OD usually refers to the optical density value when measuring a quantum dot solution sample. Usually, when measuring the OD value by UV-visible spectrophotometry, the cuvette used is 10 mm thick.

[0063] Water-soluble organic solvents

[0064] In the present invention, the boiling point and viscosity of the water-soluble organic solvent are higher than those of water. Specifically, the boiling point of the water-soluble organic solvent may be 150 to 300°C, preferably 180 to 250°C, and the viscosity at 20°C may be 25 to 100 mPa·s, preferably 40 to 80 mPa·s. The viscosity of the quantum dot ink is 5 to 15 mPa·s, preferably 8 to 12 mPa·s. It should be noted that the "viscosity" described herein is the dynamic viscosity.

[0065] The boiling point and viscosity of the water-soluble organic solvent of the present invention can be measured by the commonly used measurement methods in the art. The boiling point of the water-soluble organic solvent is measured at 1 atmosphere, and the viscosity is tested at a temperature of about 20°C.

[0066] In some specific embodiments, the water-soluble organic solvent can be selected from one or more of ethylene glycol, propylene glycol, and butylene glycol.

[0067] After adding a water-soluble organic solvent to the quantum dot aqueous solution, the surface tension of the quantum dot aqueous solution will decrease. In some specific embodiments of the present invention, the surface tension of the quantum dot ink is 40 to 60 mN·m -1 .

[0068] In the quantum dot ink of the present invention, the volume ratio of water to the water-soluble organic solvent may be 60:40 to 20:80, preferably 55:45 to 30:70, and more preferably 55:45 to 40:60. The content of the water-soluble organic solvent is 20% to 60% by volume, preferably 30% to 50% by volume, relative to the total amount of quantum dots, water and the water-soluble organic solvent.

[0069] additive

[0070] In some preferred embodiments of the present invention, in order to improve the spectral quality of the quantum dot ink, the quantum dot ink may further include additives, examples of which may include one or more of polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, and polyacrylic acid.

[0071] In the quantum dot ink of the present invention, the content of the additive is 4 volume % to 10 volume %, preferably 5 volume % to 9 volume % relative to the total amount of the quantum dots, water and the water-soluble organic solvent.

[0072] <Second Aspect>

[0073] The second aspect of the present invention relates to a quantum dot ink used in the method for encoding and storing quantum dot spectral information for spectrum consistency optimization in the above <first aspect>. The composition of the quantum dot ink in this aspect is the same as that in the above <first aspect>.

[0074] <Third Aspect>

[0075] The third aspect of the present invention relates to a method for preparing quantum dot ink. In the present invention, by adding a specific water-soluble organic solvent to the aqueous quantum dot solution and adjusting the ratio of the two, the viscosity and surface tension of the quantum dot solution are adjusted and optimized, so as to better control the volatilization process of the ink after printing, so that the quantum dots will not migrate over a large range during the solvent volatilization process, avoiding the coffee ring effect that occurs when the pure quantum dot solution is printed, so that it can form a flat film, and then can achieve better spectral consistency.

[0076] The preparation method of the quantum dot ink of the present invention comprises the following steps: adding a water-soluble organic solvent having a boiling point and a viscosity higher than that of water and an optional additive to an aqueous solution of quantum dots, thereby obtaining the quantum dot ink.

[0077] The type of water-soluble organic solvent and the ratio of the water-soluble organic solvent to water, the type and content of the additives, etc. in this aspect are the same as those in the first aspect.

[0078] The preparation of quantum dot aqueous solution is carried out by ligand exchange. It is usually prepared as follows: 2 volumes of mercaptopropionic acid and 2 volumes of water are added to 1 volume of quantum dot chloroform solution (quantum dot concentration OD = 50), the solution is layered after thorough mixing, and 2 volumes of ethanol are added to the remaining solution after removing the chloroform layer for centrifugal precipitation. Ammonia water is added to the obtained precipitate, and after complete dispersion, ethanol is used for centrifugal precipitation. The precipitated solid is washed with ethanol and finally dispersed in water, filtered through a filter membrane, and sealed and stored away from light for future use.

[0079] <Fourth Aspect>

[0080] A fourth aspect of the present invention relates to the use of quantum dot ink for encoding and storing quantum dot spectral information.

[0081] As described above, in the present invention, by adjusting and optimizing the boiling point and surface tension of the solvent in the quantum dot solution, adding solvents such as ethylene glycol to the aqueous phase quantum dot solution, and adjusting the ratio of the two, the coffee ring effect that occurs when the pure quantum dot solution is printed can be avoided, so that it can form a flat film, and thus can achieve better spatial uniformity and temporal stability of the spectral signal. Therefore, the quantum dot ink of the present invention can be well used for the purpose of quantum dot spectral information encoding and storage.

[0082] Example

[0083] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0084] Composition of quantum dot ink used for printing:

[0085] In the quantum dot ink, the quantum dots are CdSe quantum dots, the total concentration of the quantum dots is OD=6.7, [quantum dot aqueous solution + ethylene glycol (as a water-soluble organic solvent)]: polyvinyl alcohol (10wt%) (as an additive) = 70:5 (volume ratio), wherein the volume ratio of water to ethylene glycol is shown in the following table:

[0086] Sample No. 1 2 3 4 5 6 7 Water to glycol ratio 100:0 80:20 60:40 55:45 40:60 20:80 0:100

[0087] Thin film printing and morphology characterization

[0088] Substrate: glass sheet;

[0089] Printing method: Print the ink on the substrate material by printing, wait for it to dry completely after printing, and then measure it; use a microscope and a step profiler to characterize the film morphology. The results are shown in Figure 2 middle.

[0090] Depend on Figure 2 As shown, when the volume ratio of water:ethylene glycol is greater than 60:40, the coffee ring effect will always appear, resulting in a low center and high surroundings. However, when the proportion of ethylene glycol is too large, the fluidity of the film will deteriorate, the shape of the film will deviate from the circle, and there will be traces of step-type drying. Therefore, the volume ratio of water:ethylene glycol is more suitable at 60:40 to 20:80, and the more ideal volume ratio is around 55:45.

[0091] Effect of ethylene glycol ratio on the measurement error of quantum dot spectra

[0092] A thin film measurement spectrometer was also used to investigate the effect of changing the volume ratio of ethylene glycol based on the quantum dot ink of Example 1 (where the volume ratio of ethylene glycol is relative to the total amount of quantum dots, water and ethylene glycol) on the quantum dot spectrum measurement error after film formation. Specifically, the thin film measurement spectrometer error, intra-film error and inter-film error were measured. Among them, the thin film measurement spectrometer error refers to the measurement of the same position on the same film; the intra-film error refers to the measurement of different positions on the same film; the inter-film error refers to the measurement of different positions on different films. Among them, the inter-film error itself actually includes the intra-film error and the measurement error. The measurement results are shown in Figure 3 middle.

[0093] like Figure 3 As shown in Figure 2, when the volume proportion of ethylene glycol is about 30 volume %, the spectrometer error, inter-film error and intra-film error of thin film measurement are all small, and the root mean square error is about 0.1%, which is consistent with Figure 2 The quantum dot film is relatively flat. In practical applications, the root mean square error is below 0.3%. Figure 3It can be seen that the volume proportion of ethylene glycol can be 20 volume % to 60 volume %.

[0094] Effect of Additive Dosage on Quantum Dot Spectral Measurement Error

[0095] The effect of changing the volume ratio of polyvinyl alcohol as an additive (the volume ratio of PVA is relative to the total amount of quantum dots, water and water-soluble organic solvent) on the quantum dot spectrum measurement error after film formation was investigated using a thin film measurement spectrometer. Specifically, the thin film measurement spectrometer error, intra-film error and inter-film error were measured. The measurement results are shown in Figure 4 middle.

[0096] like Figure 4 As shown in FIG. 1 , when the amount of PVA added is about 5 parts by volume (the total amount of quantum dots, water and ethylene glycol is 70 parts by volume), the inter-film error is the smallest, and the root mean square error is about 0.1%. Figure 4 It can also be seen that when the volume fraction of PVA is 3 to 7 volume fractions (its volume ratio is about 4 volume % to 10 volume %), the root mean square error can meet the application requirements.

[0097] Spectral stability monitoring

[0098] Figure 5 The spectral stability monitoring of quantum dot films stored under different conditions obtained by printing with quantum dot ink of the following formula is shown: the volume ratio of quantum dot aqueous solution: ethylene glycol: PVA-205 (10wt%) is 49:21:5, wherein the ratio of water to ethylene glycol is 70:30, and the volume fraction of PVA is 5.

[0099] like Figure 5 As shown, the obtained quantum dot film is very stable, and the error of the changed spectrum compared to the initial spectrum can be controlled within 0.35% ± 0.16%, which is insensitive to temperature changes. This degree of change will not affect the accuracy of spectral recognition, and has good stability.

[0100] Information reading and recognition accuracy test

[0101] Figure 6 The simulation analysis of the influence of the error of spectral measurement on the accuracy of information reading and recognition is shown. During the test, the number of spectral channels and gradients are selected, the corresponding spectral library is constructed, and then different levels of errors are added to the spectral library, and then the corresponding spectral recognition accuracy under the error is analyzed. Figure 6 The analysis found that when the spectral consistency error can be controlled below a certain value, specifically below 0.5%, the recognition of the simple spectral library is not affected. In the present invention, the spectral measurement error can be controlled to a smaller value by adjusting the quantum dot ink formula, such as Figure 3 and Figure 4 shown.

[0102] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0103] Industrial Applicability

[0104] The method for encoding and storing quantum dot spectral information with optimized spectral consistency of the present invention can avoid the coffee ring effect during printing, so that it can form a smooth film, thereby achieving better spectral consistency, and can be used for the purpose of encoding and storing spectral information.

Claims

1. A method for encoding and storing quantum dot spectral information with optimized spectral consistency, comprising printing quantum dot ink into a film to encode and store spectral information, The quantum dot ink is composed of: quantum dots, water, a water-soluble organic solvent and an additive, wherein the boiling point and viscosity of the water-soluble organic solvent are higher than those of water, and the volume ratio of water to the water-soluble organic solvent is 60:40 to 20:80; The total concentration of the quantum dots is expressed as an optical density value of OD=3~10. The quantum dots are selected from CdS, CdSe, CdTe, ZnS, ZnSe, PbS, and PbSe. The water-soluble organic solvent is selected from one or more of ethylene glycol, propylene glycol, butylene glycol and glycerol. The additive includes polyvinyl alcohol.

2. The method according to claim 1, wherein the total concentration of the quantum dots is expressed as an optical density value of OD=5~8.

3. The method according to claim 1, wherein the viscosity of the quantum dot ink is 5-15 mPa·s.

4. The method according to any one of claims 1 to 3, wherein the surface tension of the quantum dot ink is 40 to 60 mN·m -1 .

5. The method according to any one of claims 1 to 3, wherein the content of the additive is 4 volume % to 10 volume % relative to the total amount of the quantum dots, water and the water-soluble organic solvent.

6. The method according to any one of claims 1 to 3, wherein the volume ratio between water and the water-soluble organic solvent is 55:45 to 30:

70.

7. The method according to any one of claims 1 to 3, wherein the volume ratio between water and the water-soluble organic solvent is 55:45 to 40:

60.

8. A quantum dot ink used in the method for encoding and storing quantum dot spectral information with optimized spectral consistency as described in any one of claims 1 to 7.

9. A method for preparing the quantum dot ink according to claim 8, comprising the following steps: A water-soluble organic solvent having a higher boiling point and higher viscosity than water and optional additives are added to an aqueous solution of quantum dots to obtain quantum dot ink.

10. Use of the quantum dot ink according to claim 8 for encoding and storing quantum dot spectral information.

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