CN109810703A - A room temperature preparation method of CsPbBr3 quantum dots - Google Patents

Abstract

The invention discloses a kind of CsPbBr₃The room temperature preparation method of quantum dot, it is related to semiconductive luminescent materials preparation method technical field, this method includes caesium source solution, lead source solution and the polar solvent for being dispersed with cationic surfactant, three kinds of solution is mixed, ethyl acetate is added in the crude liquid of obtained quantum dot to be dispersed, then separating-purifying is carried out, is obtained comprising CsPbBr₃The solution of quantum dot.CsPbBr proposed by the invention₃The room temperature preparation method of quantum dot; high temperature, inert gas or the protection vacuumized are not needed not only; and it can be obtained more stable perovskite quantum dot solution easy to maintain in extremely simple preparation process and by adding surfactant; the perovskite quantum dot thermodynamic stability with higher that this method is prepared simultaneously; retention cycle is longer; it can be coated in host substrate and be made into LED light emitting device, therefore on commercially producing with good application prospect.

Description

A room temperature preparation method of CsPbBr3 quantum dots

technical field

The invention relates to the technical field of preparation methods of semiconductor light-emitting materials, in particular to a room temperature preparation method of CsPbBr3 quantum dots.

Background technique

Because perovskite quantum dots have high electron-hole mobility, high luminous efficiency, and have the characteristics of wide absorption spectrum and narrow emission spectrum, the color regulation can be realized only by changing the size of the quantum dots, making the The luminous spectrum is adjustable, so it has high application potential and unique advantages in the fields of solar cells, solid-state lighting and displays. At present, the most widely used method for preparing perovskite quantum dots is the thermal injection method, which can prepare quantum dot solutions with high luminous efficiency. This method is difficult to mass produce on a large scale, which is not conducive to commercial application.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a room temperature preparation method of CsPbBr3 quantum dots, so as to solve the technical problem that the preparation of quantum dots in the prior art mentioned in the background requires high temperature heating, and also needs to be isolated from air.

In order to achieve the above purpose, the present invention provides a method for preparing CsPbBr3 quantum dots at room temperature, the key of which is to add a cationic surfactant in the process of preparing quantum dots by a sol-gel method. The specific preparation method includes: mixing cesium carbonate and n-octanoic acid according to a molar mass volume ratio (mmol: m1) of 1:10, and stirring for 5-10 minutes to obtain a cesium source solution. Dissolve lead bromide and tetraoctyl ammonium bromide in a toluene solvent according to a molar mass ratio of 1: 2, and stir for 5-10 min to obtain a lead bromide solution. Then take the cesium source solution and add it into the lead bromide solution, take the lead bromide solution as the benchmark, the volume ratio is 1:10, and stir for 5-10min. A small amount of cationic surfactant such as EHDAB (hexadecyldimethylethylammonium bromide) is added to the above mixed solution and stirred for 2-5min. Add 1-2 times the volume of ethyl acetate to the solution obtained above, then wash, separate and purify the crude solution, and disperse the precipitate obtained by final centrifugation in n-hexane solution for storage to obtain a stable CsPbBr ₃ quantum dot solution.

The present invention has the following beneficial effects:

The room temperature preparation method of CsPbBr3 quantum dots proposed in the present invention not only does not require the protection of high temperature, inert gas or vacuum, but also can obtain calcium that is more stable and easy to store in an extremely simple preparation process and by adding surfactants At the same time, the perovskite quantum dots prepared by this method have high thermodynamic stability and long storage period, and can be coated on the matrix substrate to make LED light-emitting devices, so they are suitable for commercial production. Has good application prospects.

Description of drawings

Fig. 1 is the fluorescence emission spectrum of _CsPbBr quantum dots obtained in Example 1;

Fig. 2 is the fluorescence emission spectrum of _CsPbBr quantum dots obtained in Example 2;

FIG. 3 is the fluorescence emission spectrum of the CsPbBr ₃ quantum dots prepared in Example 3. FIG.

Detailed ways

The present invention will be further described below with reference to specific embodiments to help understand the content of the present invention.

Example 1

The raw material purity used in following example of the present invention is as follows:

Cesium carbonate (99%), lead bromide (99%), oleic acid (90%), octadecene (90%), n-hexane (97%), tetraoctylammonium bromide (98%), n-octanoic acid (99%) and EHDAB (hexadecyldimethylethylammonium bromide, 98%).

CsPbBr3 quantum dots were prepared at room temperature as follows:

Step 1): Mix 0.326 g (1 mmol) of cesium carbonate and 10 ml of n-octanoic acid into a glass beaker, and stir at room temperature for 10 min to obtain a precursor solution of cesium.

Step 2): Dissolve 0.367 g (1 mmol) of lead bromide and 1.093 g (2 mmol) of tetraoctyl ammonium bromide in 5 ml of toluene, and stir for 5 min to obtain a lead source solution.

Step 3): take 0.5 ml of the cesium source solution prepared in step 1), add it to the lead source solution prepared in step 2), and stir for 5 min.

Step 4): 0.0377 g (0.1 mmol) of EHDAB was added to the solution prepared in step 3).

Step 5): add equal volume of ethyl acetate to the crude solution prepared in step 4) for dispersion.

Step 6): centrifuge the solution of step 5) at 5000rpm for 5min, then collect the precipitate separated by centrifugation, disperse in n-hexane solution, centrifuge again at 5000rpm for 5min, collect the precipitate, disperse in n-hexane to obtain Quantum dot solution.

All steps of the above preparation process are carried out at room temperature and do not require inert gas or vacuum protection.

Example 2

The raw material purity used in following example of the present invention is as follows:

Cesium carbonate (99%), lead bromide (99%), oleic acid (90%), octadecene (90%), n-hexane (97%), tetraoctylammonium bromide (98%), n-octanoic acid (99%) and CTAB (hexadecyltrimethylammonium bromide, 99%).

CsPbBr3 quantum dots were prepared at room temperature as follows:

Step 1): Mix 0.326 g (1 mmol) of cesium carbonate and 10 ml of n-octanoic acid into a glass beaker, and stir at room temperature for 10 min to obtain a precursor solution of cesium.

Step 2): Dissolve 0.367 g (1 mmol) of lead bromide and 1.093 g (2 mmol) of tetraoctyl ammonium bromide in 5 ml of toluene, and stir for 5 min to obtain a lead source solution.

Step 3): take 0.5 ml of the cesium source solution prepared in step 1), add it to the lead source solution prepared in step 2), and stir for 5 min.

Step 4): Add 0.0364 g (0.1 mmol) CTAB (hexadecyltrimethylammonium bromide) to the solution obtained in step 3).

Step 5): add equal volume of ethyl acetate to the crude solution prepared in step 4) for dispersion.

Step 6): centrifuge the solution of step 5) at 5000rpm for 5min, then collect the precipitate separated by centrifugation, disperse in n-hexane solution, centrifuge again at 5000rpm for 5min, collect the precipitate, disperse in n-hexane to obtain Quantum dot solution.

All steps of the above preparation process are carried out at room temperature and do not require inert gas or vacuum protection.

Example 3

The raw material purity used in following example of the present invention is as follows:

Cesium carbonate (99%), lead bromide (99%), oleic acid (90%), octadecene (90%), n-hexane (97%), tetraoctylammonium bromide (98%), n-octanoic acid (99%) and dodecyltrimethylammonium bromide (99%).

CsPbBr3 quantum dots were prepared at room temperature as follows:

Step 1): Mix 0.326 g (1 mmol) of cesium carbonate and 10 ml of n-octanoic acid into a glass beaker, and stir at room temperature for 10 min to obtain a precursor solution of cesium.

Step 2): Dissolve 0.367 g (1 mmol) of lead bromide and 1.093 g (2 mmol) of tetraoctyl ammonium bromide in 5 ml of toluene, and stir for 5 min to obtain a lead source solution.

Step 3): take 0.5 ml of the cesium source solution prepared in step 1), add it to the lead source solution prepared in step 2), and stir for 5 min.

Step 4): Add 0.0236 g (0.1 mm01) of dodecyltrimethylammonium bromide to the solution obtained in step 3).

Step 5): add equal volume of ethyl acetate to the crude solution prepared in step 4) for dispersion.

Step 6): centrifuge the solution of step 5) at 5000rpm for 5min, then collect the precipitate separated by centrifugation, disperse in n-hexane solution, centrifuge again at 5000rpm for 5min, collect the precipitate, disperse in n-hexane to obtain Quantum dot solution.

All steps of the above preparation process are carried out at room temperature and do not require inert gas or vacuum protection.

Specific examples are used herein to describe the inventive concept in detail, and the descriptions of the above embodiments are only used to help understand the core idea of the present invention. It should be pointed out that for those skilled in the art, any obvious modifications, equivalent replacements or other improvements made without departing from the inventive concept should be included within the protection scope of the present invention.

Claims (9)

1. a _CsPbBr Quantum dot preparation method at room temperature, is characterized in that: provide cesium source solution, lead source solution and the polar solvent dispersed with cationic surfactant, described three kinds of solutions are mixed, the quantum The crude solution of the dots was added to ethyl acetate for dispersion, and then separated and purified to obtain a solution containing CsPbBr ₃ quantum dots. 2. CsPbBr according to claim ₁ The room temperature preparation method of quantum dot is characterized in that: described cesium source solution is: cesium carbonate and n-octanoic acid are mixed, do not need to isolate air, stir at least 5min at room temperature, make cesium carbonate Completely dissolved to obtain a cesium source solution. 3. the room temperature preparation method of _CsPbBr quantum dots according to claim 1, is characterized in that: described lead source solution is: lead bromide and tetraoctyl ammonium bromide are dissolved in toluene solution simultaneously, do not need to isolate air , stirring at room temperature for at least 5min, so that the lead bromide is completely dissolved, and the lead source solution is obtained. 4. the room temperature preparation method of _CsPbBr quantum dots according to claim 1, is characterized in that: described cationic surfactant is cetyl dimethyl ethyl ammonium bromide, dodecyl trimethyl bromide ammonium or cetyltrimethylammonium bromide. 5. The room temperature preparation method of _CsPbBr quantum dots according to claim 1, wherein the polar solvent is toluene. 6. the room temperature preparation method of _CsPbBr quantum dots according to claim 1, is characterized in that: the operation that described three kinds of solutions are mixed comprises: firstly inject cesium source solution into lead source solution, at room temperature Stir for 5-10 min, and then add a polar solvent dispersed with a cationic surfactant to obtain a crude solution containing quantum dots. 7. the room temperature preparation method of _CsPbBr quantum dots according to claim 1 is characterized in that: the step of adding ethyl acetate and dispersing comprises the following operations: in the crude solution of obtained quantum dots, add 1-2 times the volume of Ethyl acetate to disperse the crude solution. 8. the room temperature preparation method of _CsPbBr quantum dots according to claim 1, is characterized in that: the separation and purification step comprises: the solution after the above-mentioned dispersion is at least 5min at least at the speed of 5000rpm centrifugation, collects the precipitation of centrifugal separation, disperses In the n-hexane solution, centrifugal purification is carried out at the same speed, and the precipitate obtained by centrifugation is again dispersed in n-hexane for centrifugal purification. 9. the room temperature preparation method of _CsPbBr quantum dots according to claim 1, is characterized in that: the composition that the solution that obtains comprises _CsPbBr quantum dots comprises is: the final precipitation obtained after centrifugal purification, dispersed and preserved in n-hexane solution , a solution containing _CsPbBr quantum dots was obtained.