Neodymium-doped phenylethylamine lead bromine single crystal capable of greatly shortening luminescence decay time and application of neodymium-doped phenylethylamine lead bromine single crystal

Abstract

The invention particularly relates to a neodymium-doped phenylethylamine lead-bromine single crystal capable of greatly shortening luminescence decay time and application of the neodymium-doped phenylethylamine lead-bromine single crystal. The technical problem that existing phenylethylamine lead-bromine single crystals are long in luminescence decay time is solved. The neodymium-doped phenylethylamine lead-bromine single crystal capable of greatly shortening the luminescence decay time is prepared by the following steps: 1) weighing; the preparation method comprises the following steps: weighing phenylethylamine hydrobromide, lead bromide and neodymium bromide, and putting into a glass bottle; the molar ratio of the phenylethylamine hydrobromide to the lead bromide to the neodymium bromide is (2.0-2.4): 0.8: 0.2; 2) obtaining a precursor solution; adding N, N-dimethylformamide into the glass bottle, heating and stirring until the N, N-dimethylformamide is completely dissolved to obtain a precursor solution; 3) obtaining a crystal; the precursor solution is filtered and then put into a glass beaker to be crystallized, the neodymium-doped phenylethylamine lead bromide single crystal is obtained, the luminescence decay time of the neodymium-doped phenylethylamine lead bromide single crystal can be greatly shortened by about 3 times, but the quantum yield of the neodymium-doped phenylethylamine lead bromide single crystal is not obviously reduced.

Description

Technical Field

[0001] The present invention specifically relates to a neodymium-doped phenylethylamine lead bromine single crystal capable of greatly shortening the luminescence decay time and application thereof. Background Art

[0002] Phenylethylamine lead bromide (PEA2PbBr4) is a two-dimensional perovskite scintillator with a natural quantum well structure and large exciton binding energy. Therefore, it can emit bright blue light when excited by ionizing radiation at room temperature. Its luminescence decay time is shorter than that of commercial scintillators such as NaI, BGO, and LYSO. In addition, its preparation process is simple and the cost is low, which has great application potential. However, its decay time is still long, which limits its application in the field of ultrafast ionizing radiation detection.

[0003] At present, the methods for adjusting the luminescence decay time all have certain limitations. For example, by replacing bromine with iodine, the luminescence decay time can be increased by an order of magnitude, but the light yield also decreases by an order of magnitude accordingly, and the luminescence center is red-shifted, and the coupling efficiency with the conventional photomultiplier tube decreases; by partially replacing bromine atoms with chlorine atoms or by doping with interstitial atoms, the light yield can be increased and the luminescence decay time can be shortened at the same time, but the effect of shortening the luminescence decay time is very limited; by replacing atoms at certain positions on the benzene ring, the luminescence decay time can be shortened to a certain extent, but the effect is poor and will significantly reduce the luminescence efficiency of the crystal. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problem that the luminescence decay time of the existing phenethylamine lead bromine single crystal is long, and to provide a neodymium-doped phenethylamine lead bromine single crystal and its application which can greatly shorten the luminescence decay time.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time is special in that it is prepared by the following steps:

[0007] 1) Weighing;

[0008] Weigh phenethylamine hydrobromide, lead bromide, and neodymium bromide and place them in a glass bottle; the molar ratio of phenethylamine hydrobromide, lead bromide, and neodymium bromide is (2.0-2.4):0.8:0.2;

[0009] 2) obtaining a precursor solution;

[0010] Add N,N-dimethylformamide to a glass bottle, heat and stir until completely dissolved to obtain a precursor solution;

[0011] 3) obtaining crystals;

[0012] The precursor solution was filtered and placed in a glass beaker for crystallization to obtain a neodymium-doped phenylethylamine lead bromide single crystal.

[0013] Furthermore, in step 1), the molar ratio of phenylethylamine hydrobromide, lead bromide and neodymium bromide in the precursor solution is 2.0:0.8:0.2.

[0014] Further, step 3) is specifically as follows:

[0015] The precursor solution is filtered and placed in a glass beaker, and a neodymium-doped phenylethylamine lead bromide single crystal is obtained by a solvent evaporation method, a cooling crystallization method, or an anti-solvent crystallization method.

[0016] Furthermore, in step 3), the amount of the neodymium substance is 0.4%±0.1% of the amount of the lead substance.

[0017] Furthermore, the method further comprises step 4):

[0018] The neodymium-doped phenylethylamine lead bromine single crystal is taken out, the surface solution is dried, and the crystal is cleaned with an anti-solvent and then vacuum-dried at room temperature to obtain a neodymium-doped phenylethylamine lead bromine single crystal scintillator.

[0019] Furthermore, in step 4), the anti-solvent is cyclohexane or chlorobenzene.

[0020] The invention also proposes the application of the single crystal in ionizing radiation.

[0021] Beneficial effects of the present invention:

[0022] The present invention discloses a neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time. By doping the neodymium element into the crystal, the luminescence decay time can be significantly shortened by about 3 times without significantly reducing the quantum yield, thus providing a new idea for the design of ultrafast scintillators. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a graph of the decay time of short-wavelength luminescence when lasers excite the neodymium-doped lead phenylethylamine bromide single crystal (Doped, blue scattered dots) and the single crystal not doped with neodymium (Pristine, red scattered dots) in Example 1 of the present invention;

[0024] Figure 2 It is a graph of the long-wavelength luminescence decay time of the laser-excited neodymium-doped lead phenylethylamine bromide single crystal (blue scattered points) and the single crystal not doped with neodymium (red scattered points) in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of 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 neodymium-doped phenylethylamine lead bromide single crystal that can significantly shorten the luminescence decay time, the specific preparation method is: weigh 20mmol phenylethylamine hydrobromide (PEABr), 8mmol lead bromide (PbBr2), 2mmol neodymium bromide (NdBr3) in a glass reagent bottle, add 6.9mL N,N-dimethylformamide (DMF), heat and stir to completely dissolve, prepare a precursor solution with a lead content of 1.45mol / L, filter the solution with a filter head with a pore size of 0.45 microns and transfer it to a 100mL glass beaker, and prepare the neodymium-doped phenylethylamine lead bromide single crystal by solvent evaporation method. Take out the neodymium-doped phenylethylamine lead bromide single crystal with tweezers, absorb the surface solution with filter paper, wash it with cyclohexane, and vacuum dry it for 24 hours before storage.

[0028] The neodymium-doped phenylethylamine lead bromine single crystal prepared by this embodiment 1 can be used in ionizing radiation.

[0029] Comparative Example

[0030] Weigh 20mmol PEABr (4.0500g) and 10mmol PbBr2 (3.6700g) in a glass reagent bottle, add 7.4mL DMF, heat and stir to completely dissolve, make a solution with a lead content of 1.35mol / L, filter the solution and transfer it to a 100mL glass beaker, and prepare phenylethylamine lead bromide single crystal by solvent evaporation method. Take out the crystal with tweezers, absorb the surface solution with filter paper, wash it with cyclohexane, and vacuum dry it for 24h before storage.

[0031] The photoluminescence spectra of undoped and neodymium-doped phenylethylamine lead bromide single crystals both contain two luminescence peaks, located at 410nm and 438nm respectively. The decay times of the two luminescence peaks are different. In order to comprehensively analyze the effect of the concentration of neodymium doping on the luminescence decay time of the crystal, the luminescence decay times of the two luminescence peaks of the two crystals were measured and compared.

[0032] like Figure 1 Shown is a luminescence decay time diagram of the short-wavelength luminescence peak of a neodymium-undoped phenethylamine lead bromide single crystal (Pristine) and a neodymium-doped phenethylamine lead bromide single crystal (Doped) prepared using Example 1 of the present invention, respectively excited by laser; the horizontal axis represents time, and the vertical axis represents luminescence intensity. Figure 1 The red scattered points are the luminescence decay time data of the undoped phenylethylamine lead bromide single crystal, the blue scattered points are the luminescence decay time data of the neodymium-doped phenylethylamine lead bromide single crystal, the red and blue solid lines are the double exponential fitting curves of the two, the luminescence lifetime τ1 of the fast luminescence component fitted by Doped is 0.98ns, and the luminescence lifetime τ2 of the slow luminescence component fitted is 3.75ns, of which the luminescence lifetime of the fast luminescence component accounts for 32.6%, and the luminescence lifetime of the slow luminescence component accounts for 67.4%. Figure 1 It can be seen that the lifetimes of the fast and slow components of the short-wavelength luminescence peak are shortened to about 1 / 3 of the original, and the luminescence lifetime ratio of the fast component is increased.

[0033] like Figure 2 The figure shows the luminescence decay time of the long-wavelength luminescence peak of the undoped Nd-doped phenylethylamine lead bromide single crystal and the Nd-doped phenylethylamine lead bromide single crystal excited by laser, respectively. The horizontal axis represents time, and the vertical axis represents luminescence intensity. Figure 2 The red and blue scattered points are the luminescence decay time data of undoped Nd-doped phenylethylamine lead bromide single crystal and Nd-doped phenylethylamine lead bromide single crystal, respectively. The red and blue solid lines are the double exponential fitting curves of the two, respectively. The luminescence lifetime τ1 of the fast luminescence component fitted by Doped is 1.80ns, and the luminescence lifetime τ2 of the slow luminescence component fitted is 6.74ns. Figure 2 It can be seen that the lifetimes of both the fast and slow components of the long-wavelength luminescence peak are shortened to about 1 / 3 of their original values.

[0034] Example 2

[0035] Weigh 22mmol phenylethylamine hydrobromide (PEABr), 8mmol lead bromide (PbBr2), and 2mmol neodymium bromide (NdBr3) in a glass reagent bottle, add 7.145mL N,N-dimethylformamide (DMF), heat and stir to completely dissolve, and prepare a precursor solution with a lead content of 1.4mol / L. Filter the solution with a filter head with a pore size of 0.45 microns and transfer it to a 100mL glass beaker. Prepare neodymium-doped phenylethylamine lead bromide single crystals by anti-solvent evaporation. Take out the neodymium-doped phenylethylamine lead bromide single crystal with tweezers and use filter paper to absorb the surface solution, then wash it with chlorobenzene and vacuum dry it for 24 hours before storage.

[0036] Example 3

[0037] Weigh 24mmol phenylethylamine hydrobromide (PEABr), 8mmol lead bromide (PbBr2), and 2mmol neodymium bromide (NdBr3) in a glass reagent bottle, add 6.45mL N,N-dimethylformamide (DMF), heat to 70°C and stir until completely dissolved to prepare a precursor solution with a lead content of 1.55mol / L. Use a 0.45 micron pore filter to filter the solution while hot into a 100mL glass beaker, and prepare neodymium-doped phenylethylamine lead bromide single crystals by cooling crystallization. Take out the neodymium-doped phenylethylamine lead bromide single crystals with tweezers and use filter paper to absorb the surface solution, then wash with cyclohexane and vacuum dry for 24 hours before storage.

[0038] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time, characterized in that: Prepared using the following steps: 1) Weighing; Weigh phenethylamine hydrobromide, lead bromide, and neodymium bromide and place them in a glass bottle; the molar ratio of phenethylamine hydrobromide, lead bromide, and neodymium bromide is (2.0-2.4):0.8:0.2; 2) obtaining a precursor solution; Add N,N-dimethylformamide to a glass bottle, heat and stir until completely dissolved to obtain a precursor solution; 3) obtaining crystals; The precursor solution was filtered and placed in a glass beaker for crystallization to obtain a neodymium-doped phenylethylamine lead bromide single crystal.

2. According to claim 1, a neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time, characterized in that: In step 1), the molar ratio of phenylethylamine hydrobromide, lead bromide and neodymium bromide in the precursor solution is 2.0:0.8:0.

2.

3. The neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time according to claim 1, characterized in that: Step 3) is specifically: The precursor solution is filtered and placed in a glass beaker, and a neodymium-doped phenylethylamine lead bromide single crystal is obtained by a solvent evaporation method, a cooling crystallization method, or an anti-solvent crystallization method.

4. A neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time according to claim 2 or 3, characterized in that: In step 3), the amount of the neodymium substance is 0.4%±0.1% of the amount of the lead substance.

5. The neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time according to claim 4, characterized in that: Also includes step 4): The neodymium-doped phenylethylamine lead bromide single crystal is taken out, the surface solution is dried, and the crystal is cleaned with an anti-solvent and then vacuum-dried at room temperature to obtain a neodymium-doped phenylethylamine lead bromide single crystal scintillator.

6. A neodymium-doped phenylethylamine lead bromide single crystal capable of significantly shortening the luminescence decay time according to claim 5, characterized in that: In step 4), the anti-solvent is cyclohexane or chlorobenzene.

7. Use of the neodymium-doped phenylethylamine lead bromide single crystal according to any one of claims 1 to 6, which can significantly shorten the luminescence decay time, in ionizing radiation.

Images