阅读说明：本技术 一种黑磷砷晶体的制备方法 (Preparation method of black phosphorus arsenic crystal ) 是由 彭聪 宋家琪 梁彦杰 赵飞平 彭兵 柯勇 刘振兴 于 2021-09-13 设计创作，主要内容包括：本发明公开了一种黑磷砷晶体的制备方法,保护性气氛或真空的密闭容器中,将灰砷、红磷和碘化锡混合后置于高温反应区域进行反应,并同步于低温沉积区域结晶沉积得到黑磷砷晶体；所述高温反应区域的温度不低于550℃,低温沉积区域的温度为450～530℃。本发明仅仅以低掺量的碘化锡作为添加剂,其同时作为矿化剂与传输剂,再协同高温反应区域和低温沉积区域的温度的严格控制,直接实现块状黑磷砷晶体的可控合成,得到的块状黑磷砷晶体尺寸可达到2-3cm,杂质量少,结晶度高,呈现出(010)单一晶面族择优生长的趋势。(The invention discloses a preparation method of black phosphorus arsenic crystal, which comprises the steps of mixing ash arsenic, red phosphorus and tin iodide in a protective atmosphere or a vacuum closed container, placing the mixture in a high-temperature reaction area for reaction, and synchronously crystallizing and depositing in a low-temperature deposition area to obtain black phosphorus arsenic crystal; the temperature of the high-temperature reaction area is not lower than 550 ℃, and the temperature of the low-temperature deposition area is 450-530 ℃. According to the invention, only low-doping tin iodide is used as an additive, and simultaneously used as a mineralizer and a transmission agent, and then the temperature of a high-temperature reaction region and a low-temperature deposition region is strictly controlled, so that the controllable synthesis of the blocky black phosphorus arsenic crystal is directly realized, the size of the obtained blocky black phosphorus arsenic crystal can reach 2-3cm, the impurity amount is small, the crystallinity is high, and the trend of preferential growth of a single crystal face family (010) is presented.)

1. A preparation method of black phosphorus arsenic crystal is characterized by comprising the following steps: in a protective atmosphere or a vacuum closed container, mixing ash arsenic, red phosphorus and tin iodide, placing the mixture in a high-temperature reaction area for reaction, and synchronously crystallizing and depositing in a low-temperature deposition area to obtain black phosphorus arsenic crystals; the temperature of the high-temperature reaction area is not lower than 550 ℃, and the temperature of the low-temperature deposition area is 450-530 ℃.

2. The method for preparing the black phosphorus-arsenic crystal according to claim 1, wherein the method comprises the following steps: the atomic ratio of the ash arsenic to the red phosphorus is 3: 1-1: 4.

3. The method for preparing the black phosphorus-arsenic crystal according to claim 2, wherein the method comprises the following steps: the atomic ratio of the ash arsenic to the red phosphorus is 2: 1-1: 1.

4. The method for preparing the black phosphorus-arsenic crystal according to claim 1, wherein the method comprises the following steps: the addition amount of the tin iodide is 1-4 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide.

5. The method for preparing the black phosphorus-arsenic crystal according to claim 4, wherein the method comprises the following steps: the addition amount of the tin iodide is 2-3 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide.

6. The method for preparing the black phosphorus-arsenic crystal according to claim 1, wherein the method comprises the following steps: the temperature of the high-temperature reaction area is 550-650 ℃, and the temperature of the low-temperature deposition area is 490-500 ℃.

7. The method for preparing the black phosphorus-arsenic crystal according to claim 1, wherein the method comprises the following steps: the reaction time is at least 12 h.

8. The method for preparing the black phosphorus-arsenic crystal according to claim 7, wherein the method comprises the following steps: the reaction time is 20-24 h.

Technical Field

The invention belongs to the technical field of preparation of high-end arsenic materials, and particularly relates to a preparation method of a black phosphorus arsenic crystal.

Background

The most advanced mid-and long-wavelength infrared detectors usually select narrow bandgap semiconductors such as tellurium-cadmium-amalgam or group III to V element based quantum well or quantum dot structure materials. However, these materials currently suffer from several important challenges in their wide-spread application. First, the growth conditions for these materials are often very complex, which makes them difficult to flexibly integrate with other semiconductors; secondly, even after the detector is manufactured, the requirement of high working environment (low temperature and stability) is met, and the use of the detector in most environments is limited under the condition of lacking complex refrigeration equipment. The discovery of the graphene provides a new idea for the application of the medium-long wave infrared detector under the room temperature condition: the two-dimensional material is applied to the manufacture of the medium-long wave infrared detector. However, the inherent zero band gap and extremely low light absorption of graphene can result in extremely high dark current and noise levels, limiting its practical application in the field of infrared detection. Currently, high performance mid-and long-wavelength infrared photodetectors capable of operating at room temperature have not been available. The black phosphorus arsenic can reach a band gap of 0.15-0.3eV by adjusting components, which means that the black phosphorus arsenic not only completely covers the middle wavelength infrared region of the spectrum, but also extends to the long wavelength infrared region (8-14 microns), and the two-dimensional material of the black phosphorus arsenic also has high carrier mobility and high on-off ratio characteristics, has unique potential which cannot be replaced in the infrared detection field, and gives new hope to the optical application of the long wavelength infrared region under the room temperature condition.

The black phosphorus-arsenic has an orthogonal lattice with a wrinkled honeycomb structure, and has strong in-plane covalent bonds and weak inter-layer van der Waals' effect, wherein the arsenic atoms and phosphorus atoms are distributed in a manner that the content of arsenic atoms is 0<As is less than or equal to 0.83, the unit cell volume of the black phosphorus arsenic crystal is in direct proportion to the proportion of arsenic atoms, and the lattice constant is usually b > c > a, wherein a, b and c are the lattice constants along the directions of zigzag, stacking and armchairs respectively. At present, a top-down method is a mainstream method for preparing black phosphorus and arsenic two-dimensional materials, and is generally a method for synthesizing black phosphorus and arsenic crystals by a chemical vapor transport method, and then the black phosphorus and arsenic two-dimensional materials are obtained by mechanical stripping or liquid phase stripping. Wherein, the synthesis of high-quality black phosphorus arsenic crystalIs key, and the existing gas-phase synthesis method mainly uses tin (Sn) and tin iodide (SnI)₄) As a transmission agent, the doping of a large amount of Sn leads to high-tin-content impurities entering the black phosphorus arsenic material, so that the synthesis of the black phosphorus arsenic material with high quality and high purity is difficult to realize.

Disclosure of Invention

The invention aims to solve the technical problem that the synthesis of a high-quality and high-purity black phosphorus arsenic material is difficult to realize due to the large doping of Sn in the existing black phosphorus arsenic preparation process, and provides a preparation method of a black phosphorus arsenic crystal, wherein only tin iodide (SnI) with relatively low doping amount is used₄) As a single transmission agent, the controllable synthesis of the black phosphorus arsenic crystal is realized.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a method for preparing black phosphorus-arsenic crystal comprises adding ash arsenic (As), red phosphorus (P) and tin iodide (SnI) in protective atmosphere or vacuum sealed container₄) Mixing, placing the mixture in a high-temperature reaction area for reaction, and synchronously crystallizing and depositing in a low-temperature deposition area to obtain black phosphorus arsenic crystals; the temperature of the high-temperature reaction area is not lower than 550 ℃, and the temperature of the low-temperature deposition area is 450-530 ℃.

Preferably, the atomic ratio of the ash arsenic (As) to the red phosphorus (P) is 3: 1-1: 4; further preferably, the atomic ratio is 2:1 to 1: 1.

Preferably, the tin iodide (SnI)₄) The addition amount of the additive is 1-4 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide; further preferably, the addition amount is 2-3 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide.

Preferably, the temperature of the high-temperature reaction area is 550-650 ℃, and the temperature of the low-temperature deposition area is 490-500 ℃.

Preferably, the reaction time is at least 12 h; further preferably 20 to 24 hours.

In the invention, raw materials of ash arsenic (As), red phosphorus (P) and transport agent of tin iodide (SnI)₄) Gasifying at the temperature of the high-temperature reaction area, transferring the formed gaseous product to the low-temperature area under the pushing of the temperature difference gradient, and crystallizing and depositing arsenic and phosphorus at the temperature of the low-temperature deposition area to obtainWhen the black phosphorus arsenic product is obtained, the gaseous iodide returns to the high-temperature reaction region under the pushing of the concentration difference, so that the transmission process is continuously carried out, and the low-doped tin iodide (SnI)₄) Meanwhile, the crystal is used as a mineralizer and a transmission agent to realize the controllable synthesis of the blocky black phosphorus arsenic crystal.

The invention has the advantages that:

1. the invention avoids large amount of tin (Sn) and tin iodide (SnI)₄) Adding raw material of ash arsenic (As) and red phosphorus (P) with only low doping amount of tin iodide (SnI)₄) As an additive, the tin doping amount is only 0.19-0.75 wt%, which is far lower than the high tin doping amount (more than 5 wt%) required by other black phosphorus and arsenic synthesis methods. Small amount of tin iodide (SnI)₄) The crystal is used as a mineralizer and a transmission agent, and is cooperated with the strict control of the temperature of a high-temperature reaction area and a low-temperature deposition area to directly realize the controllable synthesis of the massive black phosphorus arsenic crystal.

2. The size of the blocky black phosphorus arsenic crystal obtained by the invention can reach 2-3cm, the impurity amount is small, the crystallinity is high, and the trend of preferential growth of a single crystal face family (010) is presented.

Drawings

FIG. 1 is a schematic view of the gas phase reaction principle of the present invention;

FIG. 2 is a graph comparing X-ray diffraction (XRD) results of bulk black phosphorus arsenic prepared under different As-P atomic ratios in example 1 of the present invention;

FIG. 3 is a diagram of a bulk black phosphorus arsenic prepared in example 1 of the present invention with an As-P atomic ratio of 1: 1;

FIG. 4 is a Scanning Electron Microscope (SEM) image of bulk black arsenic phosphide prepared with an As-P atomic ratio of 1:1 in example 1 of the present invention;

FIG. 5 is an X-ray diffraction (XRD) pattern of bulk black phosphorus arsenic prepared according to example 1 of the present invention with an As-P atomic ratio of 1: 1;

FIG. 6 is a Raman spectrum (Raman) chart of bulk black phosphorus arsenic prepared with an As-P atomic ratio of 1:1 in example 1 of the present invention;

FIG. 7 is a comparison graph of X-ray diffraction (XRD) results of bulk black phosphorus arsenic prepared under different addition amounts of transport agents when the As-P atomic ratio is 1:1 in examples 1-5 of the present invention;

FIG. 8 is a graph comparing the X-ray diffraction (XRD) results of the bulk black phosphorus arsenic prepared under different types of transport agents in example 1 and comparative examples 1-3.

Detailed Description

The invention is illustrated below with reference to examples, but the scope of protection of the invention is not limited to the examples.

Example 1

Step 1: cleaning the quartz tube with 2% hydrofluoric acid; the raw materials of arsenic (As) and red phosphorus (P) are ground into powder for standby.

Step 2: weighing ash arsenic (As) and red phosphorus (P) with a certain atomic ratio by using a ten-thousandth electronic balance As raw materials in an inert atmosphere of a glove box, and adding the raw materials into a quartz tube;

and step 3: 3 wt% tin iodide (SnI) was weighed in a glove box under an inert atmosphere using a ten thousandth electronic balance₄) As a transmission agent, is added into a quartz tube;

and 4, step 4: plugging one end of the quartz tube by using a plug, then sealing the quartz tube by using a vacuum valve, and then taking the quartz tube out of the glove box;

and 5: vacuumizing the quartz tube by using a tube sealing machine, and sealing the quartz tube by using an oxyhydrogen machine;

step 6: horizontally placing the sealed quartz tube in a multi-temperature-zone tube furnace, setting the temperature of a double-temperature zone, then carrying out gas-phase synthesis reaction, wherein the temperature of a high-temperature reaction zone is 550 ℃, the temperature of a low-temperature deposition zone is 500 ℃, keeping the temperature for 20h, then cooling to 150 ℃, and finally naturally cooling to room temperature.

Taking the reaction system of example 1 As an example, XRD results of black phosphorus arsenic materials synthesized with different As-P atomic ratios are shown in FIG. 2, and it can be seen from the figure that black phosphorus arsenic materials can be obtained with As-P atomic ratios ranging from 3:1 to 1:4, preferably 2:1 to 1:1, and most preferably 1: 1.

In this example, the As-P atomic ratio of the synthesized material is 1:1 As shown in fig. 3; SEM results are shown in FIG. 4; the XRD results are shown in FIG. 5; the Raman results are shown in figure 6.

Example 2

As in example 1, the As-P atomic ratio was 1:1, differing only in thatTransport agent tin iodide (SnI)₄) The addition amount of the additive is 4 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide.

Example 3

As-P in example 1, the atomic ratio As-P was 1:1, except that the transport agent tin iodide (SnI)₄) The addition amount of the additive is 2 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide.

Example 4

As-P in example 1, the atomic ratio As-P was 1:1, except that the transport agent tin iodide (SnI)₄) The addition amount of the additive is 1.5 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide.

Example 5

As-P in example 1, the atomic ratio As-P was 1:1, except that the transport agent tin iodide (SnI)₄) The addition amount of the additive is 1 wt% of the total mass of the ash arsenic, the red phosphorus and the tin iodide.

Comparative example 1

As-P in example 1, the atomic ratio As-P was 1:1, except that the transport agent tin iodide (SnI)₄) Is added in an amount of 0%, i.e., tin iodide (SnI) is not added₄)。

Comparative example 2

As-P in example 1, the atomic ratio As-P was 1:1, except that the transport agents were tin (Sn) and tin iodide (SnI)₄) Wherein tin iodide (SnI)₄) The addition amount of (A) is 3 wt% of the total mass of the ash arsenic, red phosphorus, tin and tin iodide, and the addition amount of (Sn) is 12 wt% of the total mass of the ash arsenic, red phosphorus, tin and tin iodide.

Comparative example 3

As-P atomic ratio was 1:1 As in example 1, except that the transport agent was tin (Sn), tin iodide (SnI)₄) And gold (Au), in which tin iodide (SnI)₄) The addition amount of (A) is 3 wt% of the total mass of the ash arsenic, red phosphorus, gold, tin and tin iodide, (B) the addition amount of tin (Sn) is 12 wt% of the total mass of the ash arsenic, red phosphorus, gold, tin and tin iodide, and (C) the addition amount of gold (Au) is 16 wt% of the total mass of the ash arsenic, red phosphorus, gold, tin and tin iodide.

As shown in fig. 8, in comparative example 1, the ash arsenic (As) and red phosphorus (P) can not be converted by themselves to obtain black arsenic phosphorus crystals without the action of the transmission agent; ash arsenic of comparative example 2 (As), red phosphorus (P), tin (Sn) and tin iodide (SnI)₄) System and comparative example 3 of ash arsenic (As), red phosphorus (P), tin (Sn), tin iodide (SnI)₄) Although the system can realize the conversion of arsenic and phosphorus to black phosphorus arsenic material with gold (Au), the product has more impurities and poorer crystal form. The invention adopts ash arsenic (As), red phosphorus (P) and tin iodide (SnI)₄) The system can also realize the conversion of arsenic and phosphorus to black phosphorus arsenic materials, and the obtained blocky black phosphorus arsenic crystal has less impurity phases and high crystallinity and has the characteristic of single crystal face family expression of (010).