High-stability perovskite quantum dot luminescent material and preparation method thereof

Abstract

The invention provides a high-stability perovskite quantum dot luminescent material and a preparation method thereof, and relates to the technical field of perovskite quantum dots. According to the invention, certain indium is doped, the lead content is reduced, and the solvent composition is adjusted, so that the prepared perovskite quantum dot luminescent material has high luminescent stability.

Description

Technical Field

[0001] The invention relates to the technical field of perovskite quantum dots, and in particular to a high-stability perovskite quantum dot luminescent material. Background Art

[0002] Perovskite quantum dots have the characteristics of narrow emission peak width, high quantum yield, and luminescence can be regulated by halogen composition and quantum dot size. They are an ideal luminescent material for wide color gamut display. Currently, perovskite quantum dots have potential application value in many fields such as photovoltaics, LEDs, sensors, optoelectronic devices and bio-imaging.

[0003] With the continuous development of perovskite quantum dot technology, the requirements for the performance of perovskite quantum dots are getting higher and higher. At present, it is still difficult to improve the stability of perovskite quantum dots. How to further improve the stability of perovskite quantum dot materials is also a hot topic in current research. Summary of the invention

[0004] Based on this, the present invention provides a high-stability perovskite quantum dot luminescent material and a preparation method thereof. The present invention is to dope a certain amount of indium and reduce the lead content, while adjusting the solvent composition, so that the prepared perovskite quantum dot luminescent material has high luminescence stability.

[0005] The structural formula of a high-stability perovskite quantum dot luminescent material of the present invention is as follows:

[0006] Cb x In 1-x Br y I 3-y ,

[0007] In the formula, 0.2≤x≤0.3, 1≤y≤2.

[0008] The method for preparing the high-stability perovskite quantum dot light-emitting material of the present invention comprises the following steps:

[0009] Step 1: Preparation of cesium oleate precursor

[0010] Under the protection of an inert atmosphere, cesium carbonate is heated and dissolved in a mixed liquid of 1-octadecene and oleic acid to obtain a cesium oleate precursor;

[0011] Step 2: Preparation of PbInI Precursor

[0012] The organic solvent is obtained by mixing octadecene, oleylamine, myristic acid and toluene;

[0013] Under the protection of an inert atmosphere, lead bromide, indium iodide and indium bromide are dissolved in the organic solvent, and the lead indium iodide precursor is obtained after stirring and heating to fully dissolve;

[0014] Step 3: Preparation of perovskite quantum dot luminescent materials

[0015] Preheating the cesium oleate precursor and the lead indium iodine precursor respectively and setting them aside;

[0016] Under the protection of an inert atmosphere, the preheated cesium oleate precursor is poured into the preheated lead indium iodine precursor, and the reaction is stirred for 5s to 10s, and then the mixture is immediately placed in an ice water bath and cooled to room temperature, and a precipitate is obtained after centrifugation; the precipitate is washed, dried, and dissolved in an organic solvent to obtain a high-stability perovskite quantum dot light-emitting material.

[0017] Preferably, the inert atmosphere is nitrogen or argon.

[0018] Preferably, in step 1, the volume ratio of 1-octadecene to oleic acid is 1-2:2-5.

[0019] Preferably, the heating temperature in step 1 is 150°C to 160°C.

[0020] Preferably, the heating temperature in step 2 is 100-120°C.

[0021] Preferably, the preheating temperature of the cesium oleate precursor and the lead indium iodine precursor in step 3 is 150-200°C.

[0022] Preferably, in step 3, the precipitate is washed with n-hexane, dried and dissolved in n-hexane.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The quantum efficiency of the perovskite quantum dot luminescent material prepared by the present invention can reach between 65% and 70%, and the stability is also significantly improved. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the preferred embodiments of the present invention are further described in detail in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] A high-stability perovskite quantum dot luminescent material, the structural formula of which is as follows:

[0028] Cb 0.2 In 0.8 BrI2.

[0029] The preparation method of the above-mentioned high-stability perovskite quantum dot light-emitting material has the following specific steps:

[0030] Step 1: Preparation of cesium oleate precursor

[0031] Under nitrogen protection, cesium carbonate was heated and dissolved in a mixed liquid of 1-octadecene and oleic acid in a volume ratio of 1:3 to obtain a cesium oleate precursor, wherein the heating temperature was 150°C;

[0032] Step 2: Preparation of PbInI Precursor

[0033] Octadecene, oleylamine, myristic acid, and toluene are mixed in a volume ratio of 1:2:2:3 to obtain an organic solvent;

[0034] Under nitrogen protection, lead bromide, indium iodide and indium bromide are weighed according to the structural formula, and the lead bromide, indium iodide and indium bromide are dissolved in the organic solvent, and the lead indium iodide and indium bromide precursor is obtained after stirring and heating until fully dissolved, wherein the heating temperature is 100° C.;

[0035] Step 3: Preparation of perovskite quantum dot luminescent materials

[0036] Preheating the cesium oleate precursor to 160° C.; preheating the lead indium iodine precursor to 200° C. for later use;

[0037] Under nitrogen protection, the preheated cesium oleate precursor is calculated according to the structural formula and poured into the preheated lead indium iodine precursor, stirred for reaction for 5 seconds, immediately placed in an ice water bath and cooled to room temperature, and centrifuged to obtain a precipitate; the precipitate is washed with n-hexane, dried, and then dissolved in n-hexane to obtain a high-stability perovskite quantum dot luminescent material.

[0038] Example 2

[0039] A high-stability perovskite quantum dot luminescent material, the structural formula of which is as follows:

[0040] Cb 0.25 In 0.75 Br 1.5 I 1.5 .

[0041] The preparation method of the above-mentioned high-stability perovskite quantum dot light-emitting material has the following specific steps:

[0042] Step 1: Preparation of cesium oleate precursor

[0043] Under nitrogen protection, cesium carbonate was heated and dissolved in a mixed liquid of 1-octadecene and oleic acid in a volume ratio of 2:5 to obtain a cesium oleate precursor, wherein the heating temperature was 160° C.;

[0044] Step 2: Preparation of PbInI Precursor

[0045] Octadecene, oleylamine, myristic acid, and toluene are mixed in a volume ratio of 1:3:1:3 to obtain an organic solvent;

[0046] Under nitrogen protection, lead bromide, indium iodide and indium bromide are weighed according to the structural formula, and the lead bromide, indium iodide and indium bromide are dissolved in the organic solvent, and the lead indium iodide and indium bromide precursor is obtained after stirring and heating to fully dissolve, wherein the heating temperature is 120° C.;

[0047] Step 3: Preparation of perovskite quantum dot luminescent materials

[0048] Preheating the cesium oleate precursor to 160° C.; preheating the lead indium iodine precursor to 190° C. for later use;

[0049] Under nitrogen protection, the preheated cesium oleate precursor is poured into the preheated lead indium iodine precursor according to the structural formula, the reaction is stirred for 5 seconds, and then the mixture is immediately placed in an ice-water bath and cooled to room temperature. A precipitate is obtained after centrifugation. The precipitate is washed with n-hexane, dried, and dissolved in n-hexane to obtain a high-stability perovskite quantum dot luminescent material.

[0050] Example 3

[0051] A high-stability perovskite quantum dot luminescent material, the structural formula of which is as follows:

[0052] Cb 0.3 In 0.7 Br2I.

[0053] The preparation method of the above-mentioned high-stability perovskite quantum dot light-emitting material has the following specific steps:

[0054] Step 1: Preparation of cesium oleate precursor

[0055] Under nitrogen protection, cesium carbonate was heated and dissolved in a mixed liquid of 1-octadecene and oleic acid in a volume ratio of 1:2 to obtain a cesium oleate precursor, wherein the heating temperature was 160°C;

[0056] Step 2: Preparation of PbInI Precursor

[0057] Octadecene, oleylamine, myristic acid, and toluene are mixed in a volume ratio of 1:3:3:3 to obtain an organic solvent;

[0058] Under nitrogen protection, lead bromide, indium iodide and indium bromide are weighed according to the structural formula, and the lead bromide, indium iodide and indium bromide are dissolved in the organic solvent, and the lead indium iodide and indium bromide precursor is obtained after stirring and heating to fully dissolve, wherein the heating temperature is 110° C.;

[0059] Step 3: Preparation of perovskite quantum dot luminescent materials

[0060] Preheating the cesium oleate precursor to 150° C.; preheating the lead indium iodine precursor to 180° C. for later use;

[0061] Under nitrogen protection, the preheated cesium oleate precursor is calculated according to the structural formula and poured into the preheated lead indium iodine precursor, stirred for reaction for 5 seconds, immediately placed in an ice water bath and cooled to room temperature, and centrifuged to obtain a precipitate; the precipitate is washed with n-hexane, dried, and then dissolved in n-hexane to obtain a high-stability perovskite quantum dot luminescent material.

[0062] Example 4

[0063] A high-stability perovskite quantum dot luminescent material, the structural formula of which is as follows:

[0064] Cb 0.3 In 0.7 BrI2.

[0065] The preparation method of the above-mentioned high-stability perovskite quantum dot light-emitting material has the following specific steps:

[0066] Step 1: Preparation of cesium oleate precursor

[0067] Under nitrogen protection, cesium carbonate was heated and dissolved in a mixed liquid of 1-octadecene and oleic acid in a volume ratio of 1:4 to obtain a cesium oleate precursor, wherein the heating temperature was 160°C;

[0068] Step 2: Preparation of PbInI Precursor

[0069] Octadecene, oleylamine, myristic acid, and toluene are mixed in a volume ratio of 1:2:5:3 to obtain an organic solvent;

[0070] Under nitrogen protection, lead bromide, indium iodide and indium bromide are weighed according to the structural formula, and the lead bromide, indium iodide and indium bromide are dissolved in the organic solvent, and the lead indium iodide and indium bromide precursor is obtained after stirring and heating to fully dissolve, wherein the heating temperature is 120° C.;

[0071] Step 3: Preparation of perovskite quantum dot luminescent materials

[0072] Preheating the cesium oleate precursor to 160° C.; preheating the lead indium iodine precursor to 200° C. for later use;

[0073] Under nitrogen protection, the preheated cesium oleate precursor is calculated according to the structural formula and poured into the preheated lead indium iodine precursor, stirred for reaction for 5 seconds, immediately placed in an ice water bath and cooled to room temperature, and centrifuged to obtain a precipitate; the precipitate is washed with n-hexane, dried, and then dissolved in n-hexane to obtain a high-stability perovskite quantum dot luminescent material.

[0074] Comparative Example 1

[0075] A perovskite quantum dot luminescent material, the structural formula of which is as follows:

[0076] CsPbBrI2.

[0077] The preparation method of the perovskite quantum dot luminescent material comprises the following specific steps:

[0078] Step 1: Preparation of cesium oleate precursor

[0079] Under nitrogen protection, cesium carbonate was heated and dissolved in a mixed liquid of 1-octadecene and oleic acid in a volume ratio of 1:3 to obtain a cesium oleate precursor, wherein the heating temperature was 150°C;

[0080] Step 2: Preparation of lead iodine precursor

[0081] The organic solvent is obtained by mixing octadecene and oleylamine in a volume ratio of 1:2;

[0082] Under nitrogen protection, lead bromide and lead iodide are dissolved in the organic solvent according to the structural formula, and the lead indium iodide precursor is obtained after stirring and heating to fully dissolve, wherein the heating temperature is 100° C.;

[0083] Step 3: Preparation of perovskite quantum dot luminescent materials

[0084] Preheating the cesium oleate precursor to 160° C.; preheating the lead iodine precursor to 200° C. for later use;

[0085] Under nitrogen protection, the preheated cesium oleate precursor is calculated according to the structural formula and poured into the preheated lead iodine precursor, stirred for reaction for 5 seconds, immediately placed in an ice water bath and cooled to room temperature, and centrifuged to obtain a precipitate; the precipitate is washed with n-hexane, dried, and then dissolved in n-hexane to obtain a perovskite quantum dot luminescent material.

[0086] Comparative Example 2

[0087] A perovskite quantum dot luminescent material, the structural formula of which is as follows:

[0088] Cb 0.3 In 0.7 Br3.

[0089] The preparation method of the above-mentioned high-stability perovskite quantum dot light-emitting material has the following specific steps:

[0090] Step 1: Preparation of cesium oleate precursor

[0091] Under nitrogen protection, cesium carbonate was heated and dissolved in a mixed liquid of 1-octadecene and oleic acid in a volume ratio of 1:3 to obtain a cesium oleate precursor, wherein the heating temperature was 150°C;

[0092] Step 2: Preparation of lead indium precursor

[0093] The organic solvent is obtained by mixing octadecene and oleylamine in a volume ratio of 1:2;

[0094] Under nitrogen protection, lead bromide and indium bromide are weighed according to the structural formula, lead bromide, indium iodide and indium bromide are dissolved in the organic solvent, and the lead indium precursor is obtained after stirring and heating until fully dissolved, wherein the heating temperature is 100° C.;

[0095] Step 3: Preparation of perovskite quantum dot luminescent materials

[0096] Preheating the cesium oleate precursor to 160° C.; preheating the lead indium precursor to 200° C. for standby use;

[0097] Under nitrogen protection, the preheated cesium oleate precursor is calculated according to the structural formula and poured into the preheated lead indium precursor, stirred for reaction for 5 seconds, immediately placed in an ice water bath and cooled to room temperature, and centrifuged to obtain a precipitate; the precipitate is washed with n-hexane, dried, and then dissolved in n-hexane to obtain a perovskite quantum dot luminescent material.

[0098] The thermal stability test of the luminescent materials prepared in Examples 1-4 and Comparative Examples 1-2 was performed at 120° C. to 140° C., as shown in Table 1.

[0099] Table 1

[0100] Luminous intensity at 120℃ Luminous intensity at 130℃ 140℃ Luminous intensity Example 1 46.5％ 46.0％ 44.9％ Example 2 46.8％ 46.2％ 45.5％ Example 3 45.0％ 44.8％ 44.2％ Example 4 46.1％ 45.7％ 45.3％ Comparative Example 1 20.9％ 17.1％ 15.3％ Comparative Example 2 38.2％ 35.3％ 26.5％

[0101] The quantum efficiency of the luminescent materials prepared in Examples 1-4 and Comparative Examples 1-2 was tested, as shown in Table 2.

[0102] Table 2

[0103] Quantum efficiency Example 1 68.4％ Example 2 70.0％ Example 3 65.0％ Example 4 69.3％ Comparative Example 1 52.5％ Comparative Example 2 59.4％

[0104] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A high-stability perovskite quantum dot luminescent material, characterized in that: The structural formula is as follows: CsPb x In 1-x Br y I 3-y , In the formula, 0.2≤x≤0.3, 1≤y≤2.

2. The method for preparing the high-stability perovskite quantum dot luminescent material according to claim 1, characterized in that: The following steps are involved: Step 1: Preparation of cesium oleate precursor Under the protection of an inert atmosphere, cesium carbonate is heated and dissolved in a mixed liquid of 1-octadecene and oleic acid to obtain a cesium oleate precursor; Step 2: Preparation of PbInI Precursor The organic solvent is obtained by mixing octadecene, oleylamine, myristic acid and toluene; Under the protection of an inert atmosphere, lead bromide, indium iodide and indium bromide are dissolved in the organic solvent, and the lead indium iodide precursor is obtained after stirring and heating to fully dissolve; Step 3: Preparation of perovskite quantum dot luminescent materials Preheating the cesium oleate precursor and the lead indium iodine precursor respectively and setting them aside; Under the protection of an inert atmosphere, the preheated cesium oleate precursor is poured into the preheated lead indium iodine precursor, and the reaction is stirred for 5s to 10s, and then the mixture is immediately placed in an ice water bath and cooled to room temperature, and a precipitate is obtained after centrifugation; the precipitate is washed, dried, and dissolved in an organic solvent to obtain a high-stability perovskite quantum dot light-emitting material.

3. The preparation method according to claim 2, characterized in that: The inert atmosphere is nitrogen or argon.

4. The preparation method according to claim 2, characterized in that: The heating temperature in step 1 is 150°C to 160°C.

5. The preparation method according to claim 2, characterized in that: In step 1, the volume ratio of 1-octadecene to oleic acid is 1-2:2-5.

6. The preparation method according to claim 2, characterized in that: The heating temperature in step 2 is 100-120°C.

7. The preparation method according to claim 2, characterized in that: The preheating temperature of the cesium oleate precursor and the lead indium iodine precursor in step 3 is 150-200°C.

8. The preparation method according to claim 2, characterized in that: Step 3: Wash the precipitate with n-hexane, dry it and then dissolve it in n-hexane.