An abx3brx-based sub-nanosecond level scintillation material, a preparation method and application thereof

Abstract

The application provides an ABX3Brx-based sub-nanosecond level scintillation material, a preparation method and application thereof, and the molecular formula of the scintillation material is ABX3Br x Wherein, A is one alkali metal element or a combination of multiple alkali metal elements in the I main group; B is one element or a combination of multiple elements in the IV main group; X is one element or a combination of multiple elements in the VIIA group; x=0.01-0.03. The decay time of the scintillation material reaches a sub-nanosecond level at room temperature, and the scintillation material can be applied to the PET-CT and superfast pulsed ray field as a superfast scintillation material.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of ionizing radiation detection, and particularly relates to a perovskite ABX3Brx-based sub-nanosecond scintillation material based on X-site Br doping and a preparation method and application thereof. BACKGROUND

[0002] The scintillation material is mainly applied to positron emission tomography (PET-CT) and detection of fast pulsed rays (such as fast neutrons, gamma rays and alpha ions).

[0003] As the core material of a positron emission tomography instrument, the scintillation material can capture a small amount of gamma rays generated by a tracer in the human body, and the intensity and position of the signal are analyzed by the positron emission tomography instrument, so as to obtain the metabolic rate of a specific position of the human body. Cells with lesions usually have a higher metabolic rate than ordinary cells, so the signal at the lesion is particularly strong, thereby accurately locating the lesion position of the human body, which can be used for early diagnosis and treatment of cancer tumors in the medical field.

[0004] High-energy fast neutrons hit and penetrate the scintillation material, excite visible fluorescence of the scintillation material, and the signal is collected and stored by an optical system, so that pulsed fast neutron imaging can be realized.

[0005] CsPbCl3 is a colorless transparent crystal in the atmosphere, with a band gap of 2.90eV, and is a wide band gap semiconductor with good absorption capacity for ultraviolet radiation, and is a very potential ultraviolet detection material. In terms of ray detection performance, the resolution of a semiconductor ray detector based on a CsPbCl3 crystal to a 122keV gamma ray can reach 16%, and has potential application in the field of ray detection. Since this material is a direct band gap material, it is expected to be applied as a scintillation material in the field of ray detection and medical imaging.

[0006] However, the CsPbCl3 material has a free exciton luminescence property at room temperature, and the luminescence decay time is much higher than 1ns, although it has a sub-nanosecond decay phenomenon under low-temperature ultraviolet excitation, but the low-temperature condition limits its application as a scintillation material in the field of ray detection. Therefore, how to obtain a CsPbCl3 material with sub-nanosecond scintillation characteristics at room temperature is a challenge. SUMMARY

[0007] In order to solve the problems of the prior art, the application provides an ABX3Brx-based sub-nanosecond scintillation material and a preparation method and application thereof. The scintillation material has a sub-nanosecond decay time at room temperature, and can be applied as an ultrafast scintillation material in the fields of PET-CT and ultrafast pulsed rays.

[0008] The application is implemented by the following technical solutions:

[0009] An ABX3Brx-based sub-nanosecond scintillation material, having a molecular formula of ABX3Br x Wherein, A is one alkali metal element or a combination of multiple alkali metal elements in the I main group; B is one element or a combination of multiple elements in the IV main group; X is one element or a combination of multiple elements in the VIIA group; x = 0.01-0.03.

[0010] Preferably, A is one or a combination of two of Cs and Rb.

[0011] Preferably, B is one or a combination of multiple of Si, Sn, Ge and Pb.

[0012] Preferably, X is one or a combination of multiple of F, Cl and Br.

[0013] Preferably, the ABX3Br x is CsPbCl3Br x .

[0014] The preparation method of the ABX3Brx-based sub-nanosecond scintillation material, comprising:

[0015] S1, taking ABr, adding liquid bromine, ABr reacts with liquid bromine to obtain ABr3;

[0016] S2, using a solid phase method or a solution method to make AX, ABr3 and BX2 react to prepare ABX3Br x material.

[0017] Further, S1 specifically is: taking powder ABr, adding liquid bromine, making liquid bromine submerge powder ABr, ABr reacts with liquid bromine, after the reaction is completed, removing excess unreacted Br vapor to obtain powder ABr3.

[0018] Further, in S2, the ABX3Br x material is prepared by using a solid phase method, specifically comprising:

[0019] The mixture of AX, ABr3 and BX2 after mixing is put into a container, the container is vacuumed and sealed;

[0020] The mixture is heated and treated, and a polycrystalline CsPbCl3Br x material is obtained.

[0021] Further, in S2, further comprising: heating the polycrystalline CsPbCl3Br x material to a first temperature, and then gradually cooling to grow a single crystal to obtain a single crystal CsPbCl3Br x material.

[0022] The ABX3Brx-based sub-nanosecond scintillation material is applied to positron emission tomography or ultrafast pulsed radiation detection.

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

[0024] The application provides an ABX3Br x x-based sub-nanosecond ultrafast scintillation material, which is obtained by over-doping Br elements on the basis of ABX3. The over-doping of Br elements can optimize the scintillation performance of the ABX3 material, improve the photoluminescence intensity of the material, and eliminate the existence of slow-decay components in the luminescent components. The over-doping of Br elements can sharply shorten the radiation luminescence decay time of the material at room temperature from nanoseconds to sub-nanoseconds or less, so that the fluorescence decay time at room temperature reaches the sub-nanosecond level. Therefore, the ABX3Br x x-based sub-nanosecond ultrafast scintillation material has ultrafast scintillation characteristics at room temperature, and is expected to be applied to the fields of PET-CT and ultrafast pulsed radiation. The application is a full-inorganic perovskite-based scintillator, and the full-inorganic components can improve the problems of instability and easy deliquescence of traditional scintillators in the atmosphere, thereby providing some possibilities for the service environment of the scintillator in the future.

[0025] The application provides an ABX3Br x x-based sub-nanosecond ultrafast scintillation material and a preparation method thereof. The preparation method adopts a mild growth scheme to prepare ABr3 polycrystals, and introduces ABr3 into existing materials AX and BX2, so that the over-doping of Br elements is realized, and the ABX3Br x x-based sub-nanosecond ultrafast scintillation material is obtained. The application has low raw material cost.

[0026] Further, the application is synthesized by using a solid phase method, and vacuum sealing can avoid some dust in the atmosphere from entering the system, so that high-quality scintillator materials suitable for radiation detection are finally obtained. The application can also prepare polycrystalline or single-crystal ABX3Br x materials according to needs. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The application uses a simple synthesis device of a dopant CsBr3.

[0028] Figure 2 The application is CsBr3 polycrystalline raw materials synthesized in Example 1.

[0029] Figure 3 The application is CsPbCl3Br x (x=0.01, 0.02, 0.03) single crystal products finally obtained in Examples 1-3.

[0030] Figure 4The product CsPbCl3Br in Examples 1-3 of this invention x Comparison of powder XRD patterns of (x = 0.01, 0.02, 0.03) and CsPbCl3.

[0031] Figure 5 The product CsPbCl3Br in Examples 1-3 of this invention x SEM-EDS comparison of (x = 0.01, 0.02, 0.03) and CsPbCl3.

[0032] Figure 6 The product CsPbCl3Br in Examples 1-3 of this invention x (x = 0.01, 0.02, 0.03) and CsPbCl3 data fitting plot in Origin for cell constant and volume variation.

[0033] Figure 7 The product CsPbCl3Br in Examples 1-3 of this invention 0.01 CsPbCl3Br 0.02 CsPbCl3Br 0.03 A comparison of the band gap obtained from absorbance measurements with CsPbCl3.

[0034] Figure 8 The product CsPbCl3Br in Examples 1-3 of this invention 0.01 CsPbCl3Br 0.02 CsPbCl3Br 0.03 Fluorescence emission spectrum of CsPbCl3.

[0035] Figure 9 The product CsPbCl3Br in Examples 1-3 of this invention 0.01 CsPbCl3Br 0.02 CsPbCl3Br 0.03 Self-absorption spectrum of CsPbCl3.

[0036] Figure 10 The product CsPbCl3Br in Examples 1-3 of this invention 0.01 CsPbCl3Br 0.02 CsPbCl3Br 0.03 A comparison of fluorescence decay times obtained from transient fluorescence spectroscopy measurements of sample CsPbCl3.

[0037] Figure 11 The product CsPbCl3Br in Examples 1-3 of this invention x (x = 0.01, 0.02, 0.03) TG-DSC data obtained from simultaneous thermal analysis of CsPbCl3.

[0038] Figure 12 CsPbBr 0.6 Cl 2.4 CsPbBr 2.7 Cl 0.3 The fluorescence decay time diagram obtained by the transient fluorescence spectrum test of CsPbBr DETAILED DESCRIPTION

[0039] In order to further understand the present application, the present application will be described below in conjunction with examples, which are only used to further explain the features and advantages of the present application, and are not used to limit the claims of the present application.

[0040] The present application provides a perovskite structure ABX3Br x based on X-site excess doping of Br, which is a sub-nanosecond ultrafast scintillation material. The morphology of the material can be single crystal or polycrystal. The molecular formula is ABX3Br x , wherein the A-site element is a combination of one or more alkali metal elements selected from group I, for example, A is one or both of Cs and Rb; the B-site element is a combination of one or more elements selected from group IV, for example, B is one or more of Si, Sn, Ge and Pb; the X-site element is a combination of one or more elements selected from halogen elements (group VIIA elements) (excluding I), for example, X is one or more of F, Cl and Br; x = 0.01-0.03.

[0041] If there are more than two group I elements in A, the total molar content of the group I elements is in a ratio of 1:1 to the molar content of the B-site elements. If there are more than two group IVA elements in B, the total molar content of the group IVA elements is in a ratio of 1:1 to the molar content of the A-site elements. If there are more than two group VIIA elements in X, the total molar content of the group VIIA elements is in a ratio of 3:1 to the molar content of the A-site elements. The molar content of the Br element used for doping is in a ratio of 3:(0.01-0.03) to the total molar content of the X-site elements.

[0042] The above-mentioned ABX3Br x may be a solid solution structure composed of elements of the same group, for example, Cs 1-y Rb y Pb 1-z Sn z X3Br x .

[0043] In specific embodiments of the present application, the ABX3Br x is preferably ABCl3Br x , more preferably CsPbCl3Br x .

[0044] In a specific embodiment of the present invention, ABX3Br x The preferred values ​​for x are 0.01, 0.02, and 0.03.

[0045] The ABX3Br of this invention x Methods for preparing nanosecond-level ultrafast scintillation materials include:

[0046] S1. Take powdered ABr and add liquid bromine dropwise until the ABr powder is submerged. After mixing at room temperature, connect the mixture to a tail gas treatment device that can remove excess unreacted Br vapor. Place the mixture in an oil bath in a fume hood, heat and let it stand for a period of time until the liquid bromine has completely evaporated. Then, remove the product, polycrystalline ABr3 powder, and store it in a glove box. In this step, the heating temperature is preferably controlled at 95-100℃.

[0047] S2. The powdered AX raw material, the powdered ABr3 doped raw material, and the powdered BX2 raw material are reacted using a solid-state method or a solution method (but not limited to these methods) to prepare ABX3Br. x Material.

[0048] For example, the present invention uses a solid-state method to prepare ABX3Br x The material, S2, is prepared by: placing a mixture of AX, ABr3, and BX2 into a container, evacuating and sealing the container; then heating the mixture to react and obtain polycrystalline CsPbCl3Br. x Materials. Optional steps can also be taken: heat-treated polycrystalline CsPbCl3Br x The material is heated to a first temperature and then gradually cooled to grow a single crystal, yielding single-crystal CsPbCl3Br. x Material.

[0049] Single-crystal ABX3Br was prepared by solid-state method. x Taking materials as an example, the specific operation process of S2 includes:

[0050] After thoroughly mixing powdered AX raw material, powdered ABr3 doped raw material and powdered BX2 raw material in a certain stoichiometric ratio, the mixture is placed in a quartz tube and sealed using a vacuum sealing system.

[0051] The sealed quartz tube was heated and kept at a constant temperature to allow the raw materials to react. After the reaction was complete, polycrystalline CsPbCl3Br was obtained. x Remove the quartz tube;

[0052] Put the quartz tube into the Bridgman crystal growth furnace, raise the quartz tube to the top of the high temperature zone of the Bridgman furnace, heat the low, medium and high temperature zones to the target temperature (high temperature zone: 700-720, medium temperature zone: 480-500, low temperature zone: 320-340, the temperature of the high temperature zone is the first temperature described above) at a rate of 2-3 ℃ / min; according to the TG-DSC data graph obtained by simultaneous thermal analysis test, set the quartz tube descending rate, the solidification point cooling rate is kept at 0.2-0.5 mm / h, the quartz tube is lowered, the single crystal is grown, and the single crystal CsPbCl3Br is obtained x .

[0053] In specific embodiments of the present application, the molar ratio of the powder AX, the powder ABr3 and the powder BX2 is 1:(0.99-0.9967):(0.0033-0.01), for example 1:0.9967:0.0033, 1:0.9933:0.0067, 1:0.99:0.01.

[0054] In specific embodiments of the present application, the sealed quartz tube is heated and kept at 680-700 ℃ at a rate of 1-2 ℃ / min, kept at this temperature for 15-16 h, and then decreased to room temperature at a rate of 1-2 ℃ / min.

[0055] The following takes the synthesis of polycrystalline raw material and single crystal growth of CsPbCl3Br x as an example to illustrate the specific preparation process of the material of the present application, including the following steps:

[0056] Step 1, put the powder CsBr into a flask, use a pipette to add liquid bromine into the flask to submerge the CsBr powder, after mixing at room temperature, connect the exhaust treatment device which can remove excess unreacted Br vapor. Put it into an oil bath in a fume hood, control the heating temperature at 95-100 ℃, and stand for a period of time, then take out the product polycrystalline CsBr3 powder after the liquid bromine in the flask is completely volatilized, and store it in a glove box.

[0057] Step 2, mix the powder CsCl raw material, the powder CsBr3 doped raw material and the powder PbCl2 raw material in a certain stoichiometric ratio, then put them into a quartz tube, and use a vacuum sealing system to seal the tube.

[0058] Step 3, put the sealed quartz tube into a muffle furnace, heat it to 680-700 ℃ at a rate of 1-2 ℃ / min, keep it at this temperature for 15-16 h, and then decrease it to room temperature at a rate of 1-2 ℃ / min, to obtain polycrystalline CsPbCl3Br x .

[0059] Step 4, take out the quartz tube and put it into a Bridgman crystal growth furnace, heat the low, medium and high temperature zones to the target temperature at a rate of 2-3 ℃ / min, and the process needs to take 10-30 h; according to the TG-DSC data obtained by simultaneous thermal analysis test, set the quartz tube descending rate, the solidification point cooling rate is kept at 0.2-0.5 mm / h, the quartz tube is lowered, and the single crystal growth (the cycle is about 15-20 days) to obtain a single crystal CsPbCl3Br x .

[0060] According to the proportion of the raw materials put into the quartz tube in step 2, different Br-doped CsPbCl3Br 0.01 , CsPbCl3Br 0.02 , CsPbCl3Br 0.03 .

[0061] The preparation method of the CsPbCl3Br 0.01 , CsPbCl3Br 0.02 , CsPbCl3Br 0.03 provided by the application is as follows.

[0062] Example 1

[0063] CsPbCl3Br 0.01 Preparation method

[0064] Take 1 g of CsBr powder with a purity of 99.99% and put it into a flask, use a pipette to add 0.40 ml of liquid bromine with a purity of 99.5% dropwise in the flask, seal, magnetically stir, heat the reaction in an oil bath at 50 ℃, quickly plug the bottle mouth with a ground glass stopper connected with a conduit, put the tail end of the conduit into a beaker containing ethanol as a tail gas treatment device, let stand for 4 h after the liquid bromine volatilizes, take out the product in the flask, grind with a mortar to obtain orange CsBr3 powder as shown in Figure 2 . The device is shown in Figure 1 .

[0065] Take 11.255 g of CsCl powder with a purity of 99.99%, 18.654 g of PbCl2 powder with a purity of 99.99% and 0.083 g of CsBr3 powder, grind and mix uniformly, then pour the mixed raw materials into a quartz tube with the help of a long-handled funnel, then use a vacuum sealing system to vacuum the quartz tube, and then use a matched hydrogen-oxygen flame gun to sinter the quartz tube to seal it.

[0066] Put the quartz tube into a muffle furnace, set the temperature rising program to first rise to 700 ℃ at a rate of 2 ℃ / min, then keep the temperature at this temperature for 6 h, and then reduce the temperature to room temperature at a rate of 2 ℃ / min to obtain polycrystalline CsPbCl3Brx .

[0067] The quartz tube was taken out and placed in a Bridgman crystal growth furnace. The quartz tube was raised to the top end of the high temperature zone of the Bridgman furnace. The low, medium and high temperature zones were heated to the target temperature at a rate of 2 ℃ / min (high temperature zone: 700 ℃, medium temperature zone: 500 ℃, low temperature zone: 320 ℃). The process took 12 h.

[0068] According to the TG-DSC data graph obtained by simultaneous thermal analysis test, the quartz tube lowering rate was set, the freezing point cooling rate was kept at 0.2 mm / h, the quartz tube was lowered, and the crystal growth period was about 15 days, to obtain single crystal CsPbCl3Br 0.01 , for example Figure 3 .

[0069] Example 2

[0070] CsPbCl3Br 0.02 Preparation method

[0071] 1 g of CsBr powder with a purity of 99.99% was weighed into a flask, 0.4 ml of liquid bromine with a purity of 99.5% was added dropwise into the flask using a pipette, a ground glass stopper with a connecting tube was quickly plugged into the bottle mouth, and the tail end of the connecting tube was placed into a beaker containing ethanol as a tail gas treatment device. The device is shown in Figure 1 . After standing for 4 h, the liquid bromine volatilized, the product in the flask was taken out, and the orange CsBr3 powder shown in Figure 2 was obtained after grinding with a mortar.

[0072] 11.196 g of CsCl with a purity of 99.99%, 18.621 g of PbCl2 with a purity of 99.99%, and 0.167 g of CsBr3 powder were weighed, mixed uniformly using a mortar, and then poured into a quartz tube with the help of a long-handled funnel. Then the quartz tube was vacuumized using a vacuum sealing system, and then sintered using a matching hydrogen-oxygen flame gun to seal it.

[0073] The quartz tube was placed in a muffle furnace, and the temperature rising program was set to first rise to 700 ℃ at a rate of 2 ℃ / min, then keep at this temperature for 6 h, and then decrease to room temperature at a rate of 2 ℃ / min, to obtain polycrystalline CsPbCl3Br x .

[0074] The quartz tube was taken out and placed in a Bridgman crystal growth furnace. The quartz tube was raised to the top end of the high temperature zone of the Bridgman furnace. The low, medium and high temperature zones were heated to the target temperature at a rate of 2 ℃ / min (high temperature zone: 700 ℃, medium temperature zone: 500 ℃, low temperature zone: 320 ℃). The process took 12 h.

[0075] According to the TG-DSC data chart obtained by simultaneous thermal analysis test, the quartz tube descending rate is set, the freezing point cooling rate is kept at 0.2 mm / h, the quartz tube is lowered, and the crystal growth period is about 15 days, to obtain single crystal CsPbCl3Br 0.02 As shown in Figure 3 .

[0076] Example 3

[0077] CsPbCl3Br 0.03 Preparation method

[0078] 1 g of CsBr powder with a purity of 99.99% is weighed into a flask, 0.4 ml of liquid bromine with a purity of 99.5% is added dropwise into the flask using a pipette, a ground glass stopper with a connecting pipe is quickly plugged into the bottle mouth, and the tail end of the pipe is placed into a beaker containing ethanol as a tail gas treatment device. The device is as shown in Figure 1 After standing for 4 h, the liquid bromine volatilizes, the product in the flask is taken out, and the orange CsBr3 powder is obtained after grinding with a mortar.

[0079] 11.139 g of CsCl with a purity of 99.99%, 18.588 g of PbCl2 with a purity of 99.99%, and 0.249 g of CsBr3 powder are weighed, uniformly mixed by grinding with a mortar, then the mixed raw materials are poured into a quartz tube with the help of a long-handled funnel, the quartz tube is then vacuumized using a vacuum sealing system, and the quartz tube is sealed by sintering with a matching hydrogen-oxygen flame gun.

[0080] The quartz tube is placed into a muffle furnace, and the temperature rising program is set to first rise to 700℃ at a rate of 2℃ / min, then keep at this temperature for 6 h, and then decrease to room temperature at a rate of 2℃ / min, to obtain polycrystalline CsPbCl3Br x .

[0081] The quartz tube is taken out and placed into a Bridgman crystal growth furnace, the quartz tube is raised to the top end of the high temperature zone of the Bridgman furnace, the low, medium and high temperature zones are heated to the target temperature (high temperature zone: 700℃, medium temperature zone: 500℃, low temperature zone: 320℃) at a rate of 2℃ / min, and the process needs to last for 12 h.

[0082] According to the TG-DSC data chart obtained by simultaneous thermal analysis test, the quartz tube descending rate is set, the freezing point cooling rate is kept at 0.2 mm / h, the quartz tube is lowered, and the crystal growth period is about 15 days, to obtain single crystal CsPbCl3Br 0.03 As shown in Figure 3 .

[0083] Comparative Example 1

[0084] CsPbBr 0.6 Cl 2.4Preparation method

[0085] Weigh 5.69g of 99.99% pure CsCl, 9.41g of 99.99% pure PbCl, 1.80g of 99.99% pure CsBr, and 3.10g of 99.99% pure PbBr, mix them uniformly using a mortar, then pour the mixed raw materials into a quartz tube using a long-handled funnel, then use a vacuum sealing system to vacuum the quartz tube, and then use a matching hydrogen-oxygen flame gun to sinter the quartz tube to seal it.

[0086] Put the quartz tube into a muffle furnace, set the temperature rising program to first rise to 700℃ at a rate of 2℃ / min, then keep the temperature at this value for 6h, and then reduce the temperature to room temperature at a rate of 2℃ / min, to obtain polycrystalline CsPbBr 0.6 Cl 2.4 .

[0087] Take out the quartz tube and put it into a Bridgman crystal growth furnace, raise the quartz tube to the top of the high-temperature zone of the Bridgman furnace, heat the low, medium and high temperature zones to the target temperature (high temperature zone: 700℃, medium temperature zone: 500℃, low temperature zone: 320℃) at a rate of 2℃ / min, and the process takes 12h.

[0088] According to the TG-DSC data graph obtained by simultaneous thermal analysis test, set the quartz tube descending rate, the freezing point temperature reduction rate is kept at 0.2mm / h, the quartz tube is lowered, and the crystal growth period is about 15 days, to obtain single crystal CsPbBr 0.6 Cl 2.4 .

[0089] Comparative Example 2

[0090] CsPbBr 2.7 Cl 0.3 Preparation method

[0091] Weigh 0.6g of 99.99% pure CsCl, 0.98g of 99.99% pure PbCl, 6.76g of 99.99% pure CsBr, and 11.66g of 99.99% pure PbBr, mix them uniformly using a mortar, then pour the mixed raw materials into a quartz tube using a long-handled funnel, then use a vacuum sealing system to vacuum the quartz tube, and then use a matching hydrogen-oxygen flame gun to sinter the quartz tube to seal it.

[0092] Put the quartz tube into a muffle furnace, set the temperature rising program to first rise to 700℃ at a rate of 2℃ / min, then keep the temperature at this value for 6h, and then reduce the temperature to room temperature at a rate of 2℃ / min, to obtain polycrystalline CsPbBr 2.7 Cl 0.3 .

[0093] The quartz tube is taken out and placed in a Bridgman crystal growth furnace. The quartz tube is raised to the top of the high temperature zone of the Bridgman furnace, and the low, medium and high temperature zones are heated to the target temperature at a rate of 2℃ / min (high temperature zone: 700℃, medium temperature zone: 500℃, low temperature zone: 320℃). The process takes 12 hours.

[0094] According to the TG-DSC data graph obtained by simultaneous thermal analysis test, the quartz tube is set to a descending rate, the freezing point cooling rate is kept at 0.2mm / h, the quartz tube is lowered, and the crystal growth period is about 15 days. The single crystal CsPbBr 2.7 Cl 0.3 .

[0095] Figure 4 The powder XRD test results of the materials prepared in Examples 1-3 are compared with the powder XRD spectrum of CsPbCl3. It can be seen that the peak positions of the materials prepared in Examples 1-3 are basically consistent with those of CsPbCl3, and the peak position shifts to a small angle with the increase of Br doping content, indicating that the space group does not change before and after Br excessive doping.

[0096] Figure 5 The SEM-EDS test data graph of CsPbCl3Br 0.01 , CsPbCl3Br 0.02 , and CsPbCl3Br 0.03 can be seen. With the increase of Br doping amount, the Br peak gradually appears, indicating that Br is successfully incorporated.

[0097] Table 1 is the crystal cell parameters of CsPbCl3Br 0.01 , CsPbCl3Br 0.02 , and CsPbCl3Br 0.03 powder XRD test results obtained by Topas fitting and comparison with CsPbCl3. Figure 6 The crystal lattice constant and cell volume change graph of CsPbCl3Br 0.01 , CsPbCl3Br 0.02 , and CsPbCl3Br 0.03 fitted in Origin and CsPbCl3.

[0098] Table 1 is the crystal cell parameter comparison of the products CsPbCl3Br x (x=0.01, 0.02, 0.03) and CsPbCl3

[0099]

[0100] Table 1 combines Figure 6 , it can be seen that after Br excessive doping, the lattice of the material slightly expands. From the lattice constant and cell volume change graph of CsPbCl3BrFigure 6 It can be seen that, compared with undoped CsPbCl3, the CsPbCl3Br x In the CsPbCl3Br

[0101] Figure 7 The CsPbCl3Br x The band gap measurement comparison chart of CsPbCl3Br

[0102] Figure 8 The fluorescence spectrum comparison chart of the prepared material under the excitation of 375 ultraviolet laser at room temperature can be seen that the CsPbCl3Br x The peak position of CsPbCl3Br

[0103] Figure 9 The Stokes shift diagram of the prepared material, with the increase of Br doping amount, the Stokes shift gradually increases, and the self-absorption decreases.

[0104] Figure 10 The fluorescence decay time comparison chart of the prepared material and CsPbCl3 can be seen that the fluorescence lifetime of the Br doped sample is obviously shortened, and the fluorescence decay time reaches sub-nanosecond level, showing superfast flash characteristics, proving that the scheme of shortening the fluorescence lifetime of CsPbCl3 by Br over-doping is feasible.

[0105] Figure 11 The CsPbCl3Br x The TG-DSC data chart obtained by the simultaneous thermal analysis test of CsPbCl3Br It can be seen that the melting point of undoped CsPbCl3 crystal is 604.48℃, and the freezing point is 586.10℃. After over-doping, the melting point of the material slightly increases, which is 606.77℃, 605.54℃ and 605.42℃ respectively, and the freezing point also increases, which is 588.82℃, 583.65℃ and 596.15℃ respectively. It is found that the doping can slightly change the melting point and freezing point of the material, but the change of the melting point and freezing point is not the linear change expected by the present application. What is important is that there is no phase change between the melting point and the ambient temperature of the compound, which is beneficial to obtain high quality single crystal. From room temperature to decomposition temperature, the curve does not show obvious endothermic or exothermic peak, indicating that the material has no significant phase change in this temperature range, indicating that even if the material is over-doped with Br, the structure of the material still has good stability.

[0106] Figure 12 The Br substitution doping product CsPbBr prepared in Comparative Examples 1-2 of this invention 0.6 Cl 2.4 CsPbBr 2.7 Cl 0.3 The fluorescence decay time was obtained from transient fluorescence spectroscopy. The figure shows that CsPbBr... 0.6 Cl 2.4 CsPbBr 2.7 Cl 0.3 The fluorescence decay times of the products are all in the nanosecond range. Compared with the fluorescence decay time of the Br-substituted doped product, the fluorescence decay time of the product obtained by Br overdoping in this invention is even shorter, reaching the sub-nanosecond level. Figure 10 The results showed that the fluorescence lifetime of CsPbCl3 was shortened by Br overdoping relative to Br substitution doping.

[0107] The specific embodiments described above are merely illustrative of the present invention and are not intended to limit the present invention. Any modifications and equivalent substitutions made within the principles involved in the present invention should be included within the scope of protection of the present invention.

Claims

1. An ABX3Br x A method for producing a sub-nanosecond scintillation material, characterized by, ABX3Br x The molecular formula of the sub-nanosecond scintillation material is CsPbCl3Br x x=0.01-0.03; the preparation method comprises: S1, take powder CsBr, drop liquid bromine, make liquid bromine submerge powder CsBr, mix at room temperature, make CsBr react with liquid bromine, heat to 95 100℃, stand, after liquid bromine volatilizes completely, get powder CsBr3; S2, put the mixed material of CsCl, CsBr3 and PbCl2 after mixing into a container, vacuumize the container and seal; heat the mixed material to 680 700℃, keep at this temperature for 15 16h, obtain polycrystalline CsPbCl3Br x material.

2. ABX3Br according to claim 1 x Process for the preparation of a nanosecond-level scintillating material, characterized in that, In S2, further comprising: polycrystalline CsPbCl3Br x The material is heated to a first temperature, and then gradually cooled to grow a single crystal, to obtain a single crystal CsPbCl3Br x material.

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