CN108753284A - A kind of photoemissive Mn of high fluorescein:CsPbCl3The preparation method of nano-cluster - Google Patents

Abstract

A kind of preparation method of Mn: _CsPbCl3 nano-cluster of high fluorescent red light emission of the present invention belongs to the technical field of semiconductor nano-material preparation, at first, take lead chloride, oleic acid, oleylamine, octadecene and place in three In the neck bottle, vacuumize at 120°C, under the protection of nitrogen, add trioctylphosphine, dissolve at 150°C to form a mixed solution; then, lower the mixed solution to room temperature, inject cesium oleate solution, and react at room temperature to obtain CsPbCl ₃ nanoclusters ; Finally, the CsPbCl ₃ nanoclusters were purified and transferred to a mortar, and manganese salt was added for grinding to obtain Mn:CsPbCl ₃ nanoclusters. The Mn: _CsPbCl3 prepared by the present invention achieves the doping of Mn element in the _CsPbCl3 nano-cluster for the first time, and has higher red light emission efficiency. The operation of the whole reaction is simple, the raw materials are easy to obtain, and can be synthesized in large quantities, and the product has broad application prospects.

Description

A preparation method of Mn:CsPbCl3 nanoclusters with high fluorescence red light emission

technical field

The invention belongs to the technical field of semiconductor nanomaterial preparation, and relates to a method for preparing Mn: _CsPbCl3 nanoclusters with high fluorescence red light emission.

Background technique

Magic size clusters are generally defined as nanocrystals with a crystal structure size less than 2 nm and a full-shell structure of the corresponding crystal material. Because of this complete full-shell structure, magic-sized nanoclusters are thermodynamically more stable than their smaller or larger counterparts that do not have a full-shell structure. Magic size nanoclusters broaden the size range of nanocrystals, provide a model platform for the physical and chemical research of semiconductor nanocrystals at this scale, and better understand the evolution of physical and chemical properties of substances during the transition from molecular scale to nanoscale , which has certain research significance in basic research and practical application.

The transition metal doped semiconductor nanocrystal is to introduce optical or magnetic active doping ions into the semiconductor nanocrystal. By adjusting the size of II-VI, III-V semiconductor nanocrystals and doping transition metals, it has a stable visible-near-infrared emission spectrum. Not only that, transition metal doped semiconductor nanocrystals have high thermal and environmental stability. properties, high excited state lifetime, and large Stokes shift to effectively avoid self-absorption of luminescent materials, which significantly improve the application range of semiconductor nanocrystals. As early as 1983, there was a report of doping nanocrystals. Becker's group reduced the fluorescence lifetime by 5 orders of magnitude after doping Mn in ZnS nanocrystals, although it was later confirmed that the attenuation of the fluorescence lifetime observed was actually due to effect of defect emission, but interest in doped nanocrystals has continued to grow since then.

Mn ²⁺ is one of the most important doped transition metals. It is often doped in II-VI group and multi-component semiconductor nanocrystals as a means of introducing new functions, such as Mn:ZnSe, Mn:CuInS ₂ , Mn:CdS/ZnS etc., however, there are still many issues to be further studied. On the one hand, the fluorescence emitted by manganese-doped nanocrystals is mostly yellow-orange light, and the emission peak of Mn-doped nanocrystals is between 580 and 600 nm, and there are only a few phenomena that can be doped to red light. Further adjust the doped emission of manganese to red light. Red light, as one of the three primary colors of colored light, will have great application potential in the fields of display and lighting; on the other hand, the smaller the size of the doped host nanocrystal, the stronger the Quantum confinement, the interaction between the dopant and the host nanocrystal produces a huge magneto-optical and magnetoelectric response, which has important applications in products such as spin-luminescent semiconductors (spin-LEDs) and Faraday optical isolators , but due to the strong repulsion of small-sized nanocrystals to dopants, it is often difficult to obtain manganese-doped magic-sized nanoclusters.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the problems existing in the background technology and provide a preparation method of Mn:CsPbCl ₃ nano-clusters with high fluorescence red light emission for the first time.

This new preparation method proposed by the present invention is Mn: _CsPbCl3 nano-clusters prepared at low temperature, the size of the nano-clusters is uniform, and the monodispersity is good; wherein the emission peak position of Mn doped emission can reach 628nm, The fluorescence efficiency can reach 60%. Not only that, the feed of manganese salt is greatly reduced in the reaction, the reaction cost is reduced, and it is suitable for large-scale industrial production.

Above-mentioned technical problem is realized by following technical scheme:

A preparation method of Mn:CsPbCl ₃ nanoclusters with high fluorescent red light emission. First, weigh lead chloride, oleic acid, oleylamine, and octadecene in a three-necked bottle, vacuumize at 120 ° C, and protect , add trioctylphosphine, and dissolve at 150°C to form a mixed solution, wherein, for every mmol of lead chloride, use 2.5mL oleic acid, 2.5mL oleylamine, 10mL octadecene, and 2.5mL trioctylphosphine; then, the The mixed solution was lowered to room temperature, injected with a cesium oleate solution with a concentration of 0.2M, reacted at room temperature for 1h to obtain _CsPbCl3 nanoclusters, and used 1ml of cesium oleate with a concentration of 0.2M per mmol of lead chloride; finally, the _CsPbCl3 nanoclusters were placed in Centrifugal purification in an 8000rpm centrifuge and transfer to a mortar, adding manganese salts for grinding to obtain Mn:CsPbCl ₃ nano-clusters.

The manganese salt is preferably anhydrous manganese chloride or manganese chloride tetrahydrate solid powder, and the molar ratio of the manganese element in the manganese salt to the lead element in the _CsPbCl3 nano-cluster is preferably 0.25～1; the temperature during grinding is preferably no more than 30°C, the relative humidity of the environment is preferably not more than 30%.

The cesium oleate solution can be prepared as follows: weigh 2mmol cesium carbonate, 2.5mL oleic acid, and 17.5mL octadecene in a three-necked flask, vacuumize at 120°C, and heat up to 150°C under nitrogen protection. °C to obtain a 0.2M cesium oleate solution.

Beneficial effect:

The invention grinds the manganese salt and the CsPbCl ₃ nano-cluster through a grinding method, and obtains a Mn:CsPbCl ₃ nano-cluster with high fluorescence red light emission under low temperature conditions. The nanoclusters have good monodispersity, strong red light emission, and the highest fluorescence quantum efficiency can reach 60%. The operation of the whole reaction is simple, the raw materials are easy to obtain, and can be synthesized in large quantities, and the product has wide application prospects.

Description of drawings:

Fig. 1 is the absorption spectrogram of the Mn:CsPbCl ₃ nano-cluster prepared in Example 1 of the present invention.

Fig. 2 is the emission spectrogram of different Mn:CsPbCl ₃ nano-clusters prepared with the change of manganese chloride feeding amount in embodiment 1, 2, 3.

Fig. 3 is a photo of Mn:CsPbCl ₃ nanoclusters with high fluorescence red emission prepared in Example 4 of the present invention under ultraviolet light.

Fig. 4 is a photo of the highly fluorescent red emitting Mn:CsPbCl ₃ nanoclusters dispersed in n-hexane under a UV lamp prepared in Example 5 of the present invention.

Figure 5 is the XRD diffraction spectrum of the Mn:CsPbCl ₃ nanoclusters prepared in Example 6 of the present invention.

Detailed ways

Example 1:

First, weigh 2 mmol of cesium carbonate, 2.5 mL of oleic acid, and 17.5 mL of octadecene in a three-necked flask, vacuumize at 120°C, heat up to 150°C under nitrogen protection, dissolve to form a 0.2M cesium oleate solution, and drop to Standby at room temperature;

Then, weigh 0.6mmol of lead chloride, 1.5mL of oleic acid, 1.5mL of oleylamine, and 6mL of octadecene in a three-necked flask, vacuumize at 120°C, and add 1.5mL of trioctylphosphine under the protection of nitrogen. Dissolve at 150°C to form a mixed solution, cool down to room temperature in an ice-water bath, inject 0.6mL cesium oleate solution, and react at room temperature for 1 hour to obtain CsPbCl ₃ nanoclusters;

Finally, the mother liquor of CsPbCl ₃ nanoclusters was directly put into a centrifuge and centrifuged at 8000 rpm for 5 min for purification, the supernatant was discarded, and the obtained 0.12 mmol CsPbCl ₃ perovskite nanocrystal precipitate was transferred to a mortar, and 0.06 mmol anhydrous MnCl was added ₂ grinding to obtain Mn:CsPbCl ₃ nanoclusters with highly fluorescent red light emission. Its absorption spectrum is shown in Figure 1, and its emission spectrum is shown in Figure 2 (PL2).

Example 2:

First, weigh 2 mmol of cesium carbonate, 2.5 mL of oleic acid, and 17.5 mL of octadecene in a three-necked flask, vacuumize at 120°C, heat up to 150°C under nitrogen protection, dissolve to form a 0.2M cesium oleate solution, and drop to Standby at room temperature;

Then, weigh 0.6mmol of lead chloride, 1.5mL of oleic acid, 1.5mL of oleylamine, and 6mL of octadecene in a three-necked flask, vacuumize at 120°C, and add 1.5mL of trioctylphosphine under the protection of nitrogen. Dissolve at 150°C to form a mixed solution, cool down to room temperature in an ice-water bath, inject 0.6mL cesium oleate solution, and react at room temperature for 1 hour to obtain CsPbCl ₃ nanoclusters;

Finally, put the mother liquor of CsPbCl ₃ nanoclusters directly into a centrifuge and centrifuge at 8000rpm for 5min for purification, discard the supernatant, transfer the obtained 0.12mmol CsPbCl ₃ perovskite nanocrystal precipitate to a mortar, add 0.03mmol anhydrous MnCl ₂ grinding to obtain Mn:CsPbCl ₃ nanoclusters with highly fluorescent red light emission. Its absorption spectrogram is the same as the result of Example 1, and the emission spectrogram is as shown in Figure 2 (PL1).

Example 3:

First, weigh 2 mmol of cesium carbonate, 2.5 mL of oleic acid, and 17.5 mL of octadecene in a three-necked flask, vacuumize at 120°C, heat up to 150°C under nitrogen protection, dissolve to form a 0.2M cesium oleate solution, and drop to Standby at room temperature;

Then, weigh 0.6mmol of lead chloride, 1.5mL of oleic acid, 1.5mL of oleylamine, and 6mL of octadecene in a three-necked flask, vacuumize at 120°C, and add 1.5mL of trioctylphosphine under the protection of nitrogen. Dissolve at 150°C to form a mixed solution, cool down to room temperature in an ice-water bath, inject 0.6mL cesium oleate solution, and react at room temperature for 1 hour to obtain CsPbCl ₃ nanoclusters;

Finally, put the mother liquor of CsPbCl ₃ nanoclusters directly into a centrifuge and centrifuge at 8000 rpm for 5 min for purification, discard the supernatant, transfer the obtained 0.12 mmol CsPbCl ₃ perovskite nanocrystal precipitate to a mortar, add 0.12 mmol anhydrous MnCl ₂ grinding to obtain Mn:CsPbCl ₃ nanoclusters with highly fluorescent red light emission. Its absorption spectrogram is the same as the result of Example 1, and the emission spectrogram is as shown in Figure 2 (PL3).

Example 4:

First, weigh 2 mmol of cesium carbonate, 2.5 mL of oleic acid, and 17.5 mL of octadecene in a three-necked flask, vacuumize at 120°C, heat up to 150°C under nitrogen protection, dissolve to form a 0.2M cesium oleate solution, and drop to Standby at room temperature;

Then, weigh 0.2mmol of lead chloride, 0.5mL of oleic acid, 0.5mL of oleylamine, and 2mL of octadecene in a three-necked flask, vacuumize at 120°C, and add 0.5mL of trioctylphosphine under the protection of nitrogen. Dissolve at 150°C to form a mixed solution, cool down to room temperature in an ice-water bath, inject 0.2mL cesium oleate solution, and react at room temperature for 1 hour to obtain CsPbCl ₃ nanoclusters;

Finally, put the mother liquor of CsPbCl ₃ nanoclusters directly into a centrifuge and centrifuge at 8000 rpm for 5 min for purification, discard the supernatant, transfer the obtained 0.04 mmol CsPbCl ₃ perovskite nanocrystal precipitate to a mortar, add 0.02 mmol anhydrous MnCl ₂ grinding to obtain Mn:CsPbCl ₃ nanoclusters with highly fluorescent red light emission. The photos under UV light irradiation are shown in Figure 3.

Example 5:

First, weigh 2 mmol of cesium carbonate, 2.5 mL of oleic acid, and 17.5 mL of octadecene in a three-necked flask, vacuumize at 120°C, heat up to 150°C under nitrogen protection, dissolve to form a 0.2M cesium oleate solution, and drop to Standby at room temperature;

Then, weigh 3mmol of lead chloride, 7.5mL of oleic acid, 7.5mL of oleylamine, and 30mL of octadecene in a three-necked flask, vacuumize at 120°C, and add 7.5mL of trioctylphosphine under the protection of nitrogen. ℃ to dissolve to form a mixed solution, cool down to room temperature in an ice-water bath, inject 3 mL of cesium oleate solution, and react at room temperature for 1 hour to obtain CsPbCl ₃ nanoclusters;

Finally, the mother liquor of CsPbCl ₃ nanoclusters was directly put into a centrifuge and centrifuged at 8000 rpm for 5 min for purification, the supernatant was discarded, and the obtained 0.6 mmol CsPbCl ₃ perovskite nanocrystal precipitate was transferred to a mortar, and 0.3 mmol anhydrous MnCl was added ₂ grinding to obtain Mn:CsPbCl ₃ nanoclusters with highly fluorescent red light emission. The prepared Mn:CsPbCl ₃ nano-clusters dispersed in n-hexane were irradiated with ultraviolet light, as shown in Figure 4 (in red).

Embodiment 6:

First, weigh 2 mmol of cesium carbonate, 2.5 mL of oleic acid, and 17.5 mL of octadecene in a three-necked flask, vacuumize at 120°C, heat up to 150°C under nitrogen protection, dissolve to form a 0.2M cesium oleate solution, and drop to Standby at room temperature;

Then, weigh 0.6mmol of lead chloride, 1.5mL of oleic acid, 1.5mL of oleylamine, and 6mL of octadecene in a three-necked flask, vacuumize at 120°C, and add 1.5mL of trioctylphosphine under the protection of nitrogen. Dissolve at 150°C to form a mixed solution, cool down to room temperature in an ice-water bath, inject 0.6mL cesium oleate solution, and react at room temperature for 1 hour to obtain CsPbCl ₃ nanoclusters;

Finally, the mother liquor of CsPbCl ₃ nanoclusters was directly put into a centrifuge and centrifuged at 8000 rpm for 5 min for purification, the supernatant was discarded, and the obtained 0.12 mmol CsPbCl ₃ perovskite nanocrystal precipitate was transferred to a mortar, and 0.06 mmol anhydrous MnCl was added ₂ grinding to obtain Mn:CsPbCl ₃ nanoclusters with highly fluorescent red light emission. Its XRD diffraction pattern is shown in Figure 5.

Claims (3)

1. a kind of photoemissive Mn of high fluorescein:CsPbCl₃The preparation method of nano-cluster weighs lead chloride, oleic acid, oil first Amine, octadecylene are placed in three-necked bottle, and 120 DEG C vacuumize, and under nitrogen protection, tri octyl phosphine are added, and are formed in 150 DEG C of dissolvings mixed Close solution, wherein per mmol lead chlorides, use 2.5mL oleic acid, 2.5mL oleyl amines, 10mL octadecylenes, 2.5mL tri octyl phosphines；So Afterwards, mixed solution is down to room temperature, implantation concentration is the oleic acid caesium solution of 0.2M, and room temperature reaction 1h obtains CsPbCl₃Nano-cluster, The oleic acid caesium of a concentration of 0.2M of 1ml is used per mmol lead chlorides；Finally, by CsPbCl₃Nano-cluster in 8000rpm centrifuges from The heart is purified and is transferred in mortar, and manganese salt grinding is added, obtains Mn:CsPbCl₃Nano-cluster.

2. a kind of high photoemissive Mn of fluorescein according to claim 1:CsPbCl₃The preparation method of nano-cluster, feature It is, the manganese salt is anhydrous Manganese chloride or four chloride hydrate manganese solid powders, manganese element and CsPbCl in manganese salt₃Nanometer The molar ratio of lead element in cluster is 0.25~1；Temperature when grinding is no more than 30 DEG C, and envionmental humidity is no more than 30%.

3. a kind of high photoemissive Mn of fluorescein according to claim 1 or 2:CsPbCl₃The preparation method of nano-cluster, It is characterized in that, the oleic acid caesium solution can be prepared as follows：Weigh 2mmol cesium carbonates, 2.5mL oleic acid, 17.5mL octadecylenes are placed in three-necked bottle, and 120 DEG C vacuumize, and are warming up to 150 DEG C of dissolvings under nitrogen protection and are obtained 0.2M oleic acid Caesium solution.