Solid-phase synthesis method of narrow-bandgap semiconductor MTeI
阅读说明：本技术 一种窄带隙半导体MTeI的固相合成方法 (Solid-phase synthesis method of narrow-bandgap semiconductor MTeI ) 是由 杨晴 王迦卉 于 2021-09-01 设计创作，主要内容包括：本发明提供了一种窄带隙半导体MTeI的固相合成方法,包括以下步骤：将金属M单质、Te单质和过量的I-(2)单质在真空条件下进行固相反应,得到窄带隙半导体MTeI；M为Bi和/或Sb。本发明首次以金属Bi单质和/或Sb单质,Te单质及I-(2)单质作为前驱体,经简易的一步固相反应法制备了新型窄带隙半导体BiTeI和/或SbTeI晶体,合成路径简单,操作方便。以本方法所制备的窄带隙半导体BiTeI和/或SbTeI晶体结晶度高,纯度高,稳定性好,且将合成时间大幅度缩减,具有良好的实用前景。(The invention provides a solid-phase synthesis method of a narrow-bandgap semiconductor MTeI, which comprises the following steps: mixing M simple substance, Te simple substance and excessive I 2 Carrying out solid-phase reaction on the simple substance under the vacuum condition to obtain a narrow-bandgap semiconductor MTeI; m is Bi and/or Sb. The invention uses metal Bi simple substance and/or Sb simple substance, Te simple substance and I for the first time 2 The simple substance is used as a precursor, and the novel narrow-bandgap semiconductor BiTeI and/or SbTeI crystal is prepared by a simple one-step solid-phase reaction method, so that the synthesis path is simple and the operation is convenient. The narrow-bandgap semiconductor BiTeI and/or SbTeI crystal prepared by the method has high crystallinity, high purity and good stability, greatly shortens the synthesis time and has good practical prospect.)
1. A solid phase synthesis method of a narrow band gap semiconductor MTeI comprises the following steps:
mixing M simple substance, Te simple substance and excessive I2Carrying out solid-phase reaction on the simple substance under the vacuum condition to obtain a narrow-bandgap semiconductor MTeI;
m is Bi and/or Sb.
2. The method for solid-phase synthesis of MTeI in narrow bandgap semiconductors as claimed in claim 1, wherein M, Te and excess I are added2And (4) putting the simple substance into a closed vacuum container, heating to the temperature T, preserving the heat for 20 hours, and finishing the reaction.
3. The method for solid-phase synthesis of MTeI according to claim 2, wherein the temperature is raised to T at a rate of 5-20 ℃/min.
4. The method for solid-phase synthesis of MTeI according to claim 2, wherein M is Bi; t is more than or equal to 500 ℃ and less than or equal to 650 ℃.
5. The method for solid-phase synthesis of MTeI according to claim 2, wherein M is Sb; t is more than or equal to 350 ℃ and less than or equal to 450 ℃.
Technical Field
The invention belongs to the technical field of semiconductor materials, and particularly relates to a solid-phase synthesis method of a narrow-bandgap semiconductor MTeI.
Background
The BiTeI compound is a compound consisting of heavy elements, and electrons of the BiTeI compound have strong correlation effect, so that a plurality of interesting properties are intensively researched by physicists. However, the synthesis of this compound has been one of the difficulties hindering its development. Therefore, the development of a synthesis method with lower cost, convenience and rapidness is urgently needed for the materials.
Disclosure of Invention
The invention aims to provide a solid-phase synthesis method of narrow-bandgap semiconductor MTeI, and the narrow-bandgap semiconductor MTeI crystal prepared by the method has high crystallinity, good stability and good practical prospect.
The invention provides a solid-phase synthesis method of a narrow-bandgap semiconductor MTeI, which comprises the following steps:
mixing M simple substance, Te simple substance and excessive I2Simple substance is in trueCarrying out solid phase reaction under an empty condition to obtain a narrow-bandgap semiconductor MTeI;
m is Bi and/or Sb.
Preferably, the metal M, Te and excessive I2And (4) putting the simple substance into a closed vacuum container, heating to the temperature T, preserving the heat for 20 hours, and finishing the reaction.
Preferably, the temperature is increased to the temperature T at the speed of 5-20 ℃/min.
Preferably, M is Bi; t is more than or equal to 500 ℃ and less than or equal to 650 ℃.
Preferably, M is Sb; t is more than or equal to 350 ℃ and less than or equal to 450 ℃.
The invention provides a solid-phase synthesis method of a narrow-bandgap semiconductor MTeI, which comprises the following steps: mixing M simple substance, Te simple substance and excessive I2Carrying out solid-phase reaction on the simple substance under the vacuum condition to obtain a narrow-bandgap semiconductor MTeI; m is Bi and/or Sb. The invention uses metal Bi simple substance and/or Sb simple substance, Te simple substance and I for the first time2The simple substance is used as a precursor, and the novel narrow-bandgap semiconductor BiTeI and/or SbTeI crystal is prepared by a simple one-step solid-phase reaction method, so that the synthesis path is simple and the operation is convenient. The narrow-bandgap semiconductor BiTeI and/or SbTeI crystal prepared by the method has high crystallinity, high purity and good stability, greatly shortens the synthesis time and has good practical prospect.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) dispersed in ethanol of a narrow bandgap semiconductor BiTeI prepared in example 1 (a-b);
FIG. 2 is a High Resolution Transmission Electron Micrograph (HRTEM) (a) of the narrow bandgap semiconductor BiTeI prepared in example 1, and a high angle annular dark field image (HAADF-STEM) and Mapping photograph (b) of the contained elements;
FIG. 3 is an X-ray photoelectron Spectroscopy (XPS) of the elements Bi4f (b), Te3d (c), I3 d (d) and the total spectra (a) of the narrow bandgap semiconductor BiTeI prepared in example 1;
FIG. 4 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the narrow bandgap semiconductor BiTeI prepared in comparative example 1;
FIG. 5 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the narrow bandgap semiconductor BiTeI prepared in example 2;
FIG. 6 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the narrow bandgap semiconductor BiTeI prepared in example 3;
FIG. 7 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the narrow bandgap semiconductor BiTeI prepared in comparative example 2;
FIG. 8 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the narrow bandgap semiconductor SbTeI prepared in example 4;
FIG. 9 is an X-ray diffraction pattern (XRD) of the narrow bandgap semiconductor SbTeI prepared in comparative example 3.
Detailed Description
The invention provides a solid-phase synthesis method of a narrow-bandgap semiconductor MTeI, which comprises the following steps:
mixing M simple substance, Te simple substance and excessive I2Carrying out solid-phase reaction on the simple substance under the vacuum condition to obtain a narrow-bandgap semiconductor MTeI;
m is Bi and/or Sb.
In the present invention, the excess of I2Simple substance means I in a slight excess, not exceeding 1.2 times, calculated as the stoichiometric ratio2Simple substance.
The invention preferably selects the simple substance M, the simple substance Te and the excessive I2Placing the simple substance in a quartz tube, sealing the quartz tube in a vacuum state in a holding tube, obliquely placing the sealed quartz tube in a muffle furnace, and keeping the reactant at the bottom of the quartz tube.
Then, the muffle furnace was heated to a temperature T, and the temperature was maintained for 20 hours to terminate the reaction.
In the invention, the temperature is raised to the temperature T preferably at a rate of 5-20 ℃/min, more preferably 6-15 ℃/min, such as 5 ℃/min, 6 ℃/min, 7 ℃/min, 8 ℃/min, 9 ℃/min, 10 ℃/min, 11 ℃/min, 12 ℃/min, 13 ℃/min, 14 ℃/min, 15 ℃/min, preferably the range value taking any value as the upper limit or the lower limit;
in the present invention, M is Bi; t is more than or equal to 500 ℃ and less than or equal to 650 ℃;
m is Sb; t is more than or equal to 350 ℃ and less than or equal to 450 ℃.
After the reaction is finished, naturally cooling to room temperature to obtain a large solid MTeI product with metallic luster.
Such control I in the invention2The excessive one-step synthesis method is simple to operate, novel in concept, and greatly shortened in reaction time compared with the existing method, and can be widely applied to the control preparation of other M-VIA-VIIA compounds.
The invention provides a solid-phase synthesis method of a narrow-bandgap semiconductor MTeI, which comprises the following steps: mixing M simple substance, Te simple substance and excessive I2Carrying out solid-phase reaction on the simple substance under the vacuum condition to obtain a narrow-bandgap semiconductor MTeI; m is Bi and/or Sb. The invention uses metal Bi simple substance and/or Sb simple substance, Te simple substance and I for the first time2The simple substance is used as a precursor, and the novel narrow-bandgap semiconductor BiTeI and/or SbTeI crystal is prepared by a simple one-step solid-phase reaction method, so that the synthesis path is simple and the operation is convenient. The narrow-bandgap semiconductor BiTeI and/or SbTeI crystal prepared by the method has high crystallinity, high purity and good stability, greatly shortens the synthesis time and has good practical prospect.
In order to further illustrate the present invention, the following will describe the solid phase synthesis method of a narrow bandgap semiconductor MTeI provided by the present invention in detail with reference to the examples, but it should not be construed as limiting the scope of the present invention.
Example 1
0.5mmol of bismuth [ Bi ] is taken]Elemental powder, 0.5mmol of tellurium [ Te ]]Elemental powder and slightly more than 0.25mmol of elemental iodine [ I2]The quartz tube was placed in a quartz tube having an inner diameter of 8mm, and the quartz tube was sealed while maintaining the inside of the tube in a vacuum state. The sealed quartz tube is inclinedPlaced in a muffle furnace, and reactants are kept at the bottom of a quartz tube. The muffle furnace is heated to about 500 ℃ after a certain period of time, and the temperature is kept for 20 hours at the temperature. And naturally cooling the muffle furnace to room temperature after the reaction is finished to obtain a bulk solid BiTeI product with metallic luster.
The morphology, structure, phase, composition and the like of the BiTeI product are characterized as follows:
BiTeI belongs to the P3m1 space group, and the X-ray diffraction pattern (XRD) thereof is shown in FIG. 1a, wherein the 2 theta peaks at 12.932 °, 23.675 °, 26.033 °, 27.067 °, 35.474 °, 39.492 °, 41.624 °, 43.768 °, 46.563 °, 50.358 °, 53.547 °, 55.813 °, 58.719 °, 59.336 °, 64.210 °, 67.325 ° and 68.539 ° can accurately correspond to the (001), (100), (002), (011), (102), (003), (110), (11-1), (103), (201), (004), (022), (11-3), (014), (023), (21-1) and (005) diffraction crystal planes (JCPDS 01-082-0484) of the material, respectively. No undesired peaks were observed in the figure, indicating that the BiTeI prepared by the simple one-step method proposed in this experiment is pure phase and has high crystallinity. Figure 1b is an SEM photograph of a BiTeI sample dispersed in ethanol, the sample morphology appearing as a uniform curled sheet.
BiTeI was calibrated in a High Resolution Transmission Electron Micrograph (HRTEM) (FIG. 2a) where the 0.227nm and 0.329nm lattice fringes corresponded exactly to the (003) and (011) crystal planes of BiTeI. Fig. 2b is a photograph of a high angle annular dark field image (HAADF-STEM) and Mapping of the three basic elements Bi, Te and I, respectively, constituting the sample, showing that the three elements are uniformly distributed inside the material, demonstrating the successful preparation of the BiTeI material.
X-ray photoelectron spectroscopy (XPS) reflects information such as the composition of elements in a material and the chemical state of each element. For the BiTeI material (FIGS. 3a-d), only the electron-corresponding peaks of the Bi, Te, I elements and the unavoidable C1s and O1s peaks in the XPS survey spectrum indicate that the synthesized BiTeI sample is a pure phase. In the fine spectrum of Bi4f (FIG. 3b), characteristic peaks at binding energies of 164.0 and 158.8eV, respectively, were observed, and in FIG. 3c, the fine XPS spectrum of Te3d consisted of Te3d at 583.2 and 587.2eV3/2Peak atTe3d of 572.8 and 576.8eV5/2Peak composition. FIG. 3d is a drawing of an I3 d at 630.83/2Peak sum of I3 d at 619.3eV5/2Peak composition.
Through the above discussion and analysis, the one-step method provided by the invention is proved to be successful in obtaining the narrow-bandgap semiconductor BiTeI material. The preparation method is simple to operate, novel in concept, greatly shortened in reaction time, and capable of synthesizing the high-crystallinity narrow-bandgap semiconductor BiTeI material.
Comparative example 1
Adopts a traditional two-step reaction method, firstly melts and then slowly cools to the reaction temperature. The same amount of 0.5mmol of bismuth [ Bi ] as in example 1 was taken]Elemental powder, 0.5mmol of tellurium [ Te ]]Elemental powder and slightly more than 0.25mmol of elemental iodine [ I2]The quartz tube was placed in a quartz tube having an inner diameter of 8mm, and the quartz tube was sealed while maintaining the inside of the tube in a vacuum state. The sealed quartz tube was placed inside the muffle furnace with an inclination to keep the reactants at the bottom of the quartz tube. The temperature of the muffle furnace is raised to 600 ℃ after 90min, then the temperature is slowly lowered to 500 ℃ within 8 hours, and the muffle furnace is naturally cooled to the room temperature after the temperature is kept for 24 hours. FIG. 4 is an X-ray diffraction pattern (XRD) and a Scanning Electron Micrograph (SEM) of the sample prepared in comparative example 1, the XRD results showing that Bi of a binary phase is present in the synthesized sample in addition to BiTeI, an object product4Te3And TeI0.44Impurities. It is stated that when the same reaction temperature of 500 ℃ is chosen as in the process shown in this patent, the product obtained contains other impurities. From the scanning electron micrograph, the large lamellar morphology of the agglomerate is mainly, the size of the agglomerate cannot be effectively reduced even if the agglomerate is subjected to ultrasonic treatment in an ethanol solution, and the solubility of the agglomerate is poor. In conclusion, compared with the traditional two-step reaction method, the method can shorten the reaction time by at least 12 hours under the same reaction temperature condition to obtain the narrow-bandgap semiconductor BiTeI with higher purity and better crystallinity; in addition, the BiTeI crystal obtained by the method has good solubility in an ethanol solution, so that the BiTeI film obtained by spin coating can be conveniently contacted with a silicon wafer and a graphene electrode well to be used as a junction type or photoconductive type photoelectric detector, and the BiTeI crystal can be applied to communication, imaging, military detection and other aspects with more value.
Example 2
The same amount of 0.5mmol of bismuth [ Bi ] as in example 1 was taken]Elemental powder, 0.5mmol of tellurium [ Te ]]Elemental powder and slightly more than 0.25mmol of elemental iodine [ I2]The quartz tube was placed in a quartz tube having an inner diameter of 8mm, and the quartz tube was sealed while maintaining the inside of the tube in a vacuum state. The sealed quartz tube was placed inside the muffle furnace with an inclination to keep the reactants at the bottom of the quartz tube. After the muffle furnace is heated to 550 ℃ for a certain time, the temperature is kept for 20 hours. And naturally cooling the muffle furnace to room temperature after the reaction is finished to obtain a bulk solid BiTeI product with metallic luster. Figure 5 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the BiTeI prepared in example 2, where all diffraction peak positions in the XRD match the crystal planes of the BiTeI, indicating that pure, well-crystallized, narrow-bandgap semiconductor BiTeI products can still be synthesized at a temperature of 550 ℃.
Example 3
The same amount of 0.5mmol of bismuth [ Bi ] as in example 1 was taken]Elemental powder, 0.5mmol of tellurium [ Te ]]Elemental powder and slightly more than 0.25mmol of elemental iodine [ I2]The quartz tube was placed in a quartz tube having an inner diameter of 8mm, and the quartz tube was sealed while maintaining the inside of the tube in a vacuum state. The sealed quartz tube was placed inside the muffle furnace with an inclination to keep the reactants at the bottom of the quartz tube. After the temperature of the muffle furnace is raised to 600 ℃ for a certain time, the muffle furnace is directly kept at the temperature for 20 hours. And naturally cooling the muffle furnace to room temperature after the reaction is finished to obtain a large solid product with metallic luster. Fig. 6 is an X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the BiTeI prepared in example 3, showing that pure narrow bandgap semiconductor BiTeI bulk can be synthesized at this temperature as well, and that the XRD pattern has sharper peaks and smaller half-widths than example 2, demonstrating that higher temperatures favor the production of BiTeI with better crystallinity.
Comparative example 2
The same amount of 0.5mmol of bismuth [ Bi ] as in example 1 was taken]Elemental powder, 0.5mmol of tellurium [ Te ]]Elemental powder and slightly more than 0.25mmol of elemental iodine [ I2]The quartz tube was placed in a quartz tube having an inner diameter of 8mm, and the quartz tube was sealed while maintaining the inside of the tube in a vacuum state. Placing the sealed quartz tube in a muffle furnace obliquely, and keeping reactants in the quartzThe bottom of the tube. The muffle furnace was heated to 700 ℃ over a period of time and held at this temperature for 20 hours. And after the reaction is finished, the muffle furnace is naturally cooled to room temperature. FIG. 7 shows the X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of the sample prepared in comparative example 2, and the XRD results show that the sample synthesized at this time is mainly BiTeI as the target product and Bi as a binary phase2Te3And TeI4Impurities. The temperature is over high at this moment, the obtained product contains more impurities, and the temperature condition is not suitable for synthesizing the narrow-bandgap semiconductor BiTeI.
Example 4
0.5mmol of antimony [ Sb ]]Elemental powder, 0.5mmol of tellurium [ Te ]]Elemental powder and slightly more than 0.25mmol of elemental iodine [ I2]The quartz tube was placed in a quartz tube having an inner diameter of 8mm, and the quartz tube was sealed while maintaining the inside of the tube in a vacuum state. The sealed quartz tube was placed inside the muffle furnace with an inclination to keep the reactants at the bottom of the quartz tube. The muffle furnace is heated to about 350 ℃ after a certain period of time, and the temperature is kept for 20 hours at the temperature. And after the reaction is finished, naturally cooling the muffle furnace to room temperature, and collecting the rod-shaped product which is found to be attached to the wall of the quartz tube for later use. FIG. 8 shows the X-ray diffraction pattern (XRD) and Scanning Electron Micrograph (SEM) of SbTeI prepared in example 4, in which no extra peaks were observed by XRD. In addition, it can be seen from the SEM photograph that the product has a clear rod-like structure, which is consistent with the C2/m space group of SbTeI crystals. This demonstrates such control I2The solid phase method with excess has popularization in preparing the substances. In addition, the prepared SbTeI crystal has a rod-shaped structure, and a metal-semiconductor-metal structured photodetector is easy to prepare.
Comparative example 3
The same amount of elemental powder as in example 4 was charged into a quartz tube by a conventional two-step reaction method, and the quartz tube was sealed while maintaining the vacuum state in the tube. The sealed quartz tube was placed in a muffle furnace with an inclination. And (3) heating the muffle furnace to 400 ℃ after 90min, slowly cooling to 350 ℃ after 8 hours, preserving the temperature for 24 hours, and naturally cooling the muffle furnace to room temperature after the reaction is finished. The amount of crystals obtained in comparative example 3 was small compared to that of SbTeI prepared by the method of example 4, and it can be seen from the X-ray diffraction pattern (XRD) of SbTeI shown in FIG. 9 that the crystals prepared by this method were poor in crystallinity.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
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