Layered selenide ge3sb2se5 semiconductor material and method of preparation thereof

Abstract

The present application relates to the technical field of crystal material preparation, in particular to a layered selenide Ge3Sb2Se5 semiconductor material and a preparation method thereof. The preparation method of the layered selenide Ge3Sb2Se5 semiconductor material comprises the following steps: grinding Ge3Sb4Se7 material and placing it in a quartz tube, adding iodine particles, vacuum packaging in the quartz tube, placing the end of the quartz tube with raw materials in a high-temperature zone and the end without raw materials in a low-temperature zone; increasing the temperature, so that the temperature of the low-temperature zone end is 400±25 DEG C and the temperature of the high-temperature zone end is 500±25 DEG C, after heat preservation for 7 days, naturally cooling to room temperature, and obtaining Ge3Sb2Se5 semiconductor material. The crystal structure of the Ge3Sb2Se5 semiconductor material belongs to the orthorhombic system, has the characteristics of low thermal conductivity and low resistivity. The preparation method can stably prepare Ge3Sb2Se5 semiconductor material, and provides materials for physical property research and preparation of semiconductor optoelectronic devices.

Description

Technical Field

[0001] This invention relates to the field of crystal material preparation technology, and in particular to a layered selenide Ge3Sb2Se5 semiconductor material and its preparation method. Background Technology

[0002] Layered chalcogenides are formed by stacking two-dimensional or quasi-two-dimensional layered building blocks along a specific direction. The layers are connected within their planes by stable ionic / covalent bonds, and van der Waals interactions exist between the layers. These materials possess ample tunable space for chemical composition and phase structure, allowing for effective control over their bandgap structure, crystal structure, and functional properties. They show promising application prospects in numerous fields, including photodetectors, gas sensors, spintronics, and thermoelectric devices.

[0003] In the Ge-Sb-Se ternary system, two compounds, GeSb2Se3 and Ge3Sb4Se7, have been discovered (Inorganic Chemistry, 2020, 59(16), 11207-11212). These compounds exhibit layered structural characteristics similar to black phosphorus and SnSe, and are indirect bandgap semiconductor materials. Due to their low thermal conductivity and low resistivity, they are expected to be applied in thermoelectric devices, photoelectric detection, and other fields.

[0004] The objective of this invention is to successfully synthesize the ternary layered selenide Ge3Sb2Se5 material, providing a technical reference for the controllable growth of Ge-Sb-Se compounds, and further providing material support for related property studies, device development and applications. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a layered selenide Ge3Sb2Se5 semiconductor material and its preparation method, aiming to clarify the preparation process of Ge3Sb2Se5 material and provide material support for its physical property research and functional device fabrication.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this invention provides a method for preparing a layered selenide Ge3Sb2Se5 semiconductor material, comprising the following steps:

[0008] S01. Grind the Ge3Sb4Se7 material and place it in a quartz tube. Add iodine particles and vacuum seal the quartz tube. Place the end of the quartz tube with the raw material in the high-temperature zone and the end without the raw material in the low-temperature zone.

[0009] S02. Heat up to 400±25℃ at the low-temperature end and 500±25℃ at the high-temperature end. After holding at this temperature for 7 days, allow the vacuum-sealed quartz tube to cool naturally to room temperature. The resulting growth material is Ge3Sb2Se5 semiconductor material.

[0010] The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material, wherein the amount of iodine particles added is 4-6 mg / mL.

[0011] The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material includes a heating rate of 1-5℃ / min during heating, with the high and low temperature regions simultaneously reaching the set temperature.

[0012] The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material, wherein the vacuum degree of the quartz tube is ≤1Pa.

[0013] The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material includes, in step S02, after the quartz tube is naturally cooled to room temperature, cleaning and drying of the generated material.

[0014] The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material, wherein step S02, the method for preparing the Ge3Sb4Se7 material, includes the following steps:

[0015] A01. Using germanium powder, antimony powder, and selenium powder in a molar ratio of 3:4:7 as raw materials, the raw materials are mixed and placed in a quartz tube. Under vacuum conditions, the temperature is raised to 900-950℃ and kept at this temperature for 12-24 hours.

[0016] A02. After the heat preservation is completed, the temperature is reduced to 475-500℃ at a cooling rate of 1-5℃ / min, and then kept at this temperature for 3-5 days. After the heat preservation is completed, the material is cooled to room temperature with the furnace to obtain the Ge3Sb4Se7 material.

[0017] The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material, wherein in step S02, in step A01, the heating rate is 1-5℃ / min.

[0018] The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material, wherein in step S02, the vacuum degree of step A01 is ≤1 Pa.

[0019] A second aspect of the present invention provides a layered selenide Ge3Sb2Se5 semiconductor material, which is prepared by the method described above for preparing the layered selenide Ge3Sb2Se5 semiconductor material.

[0020] Beneficial effects: This invention provides a method for preparing layered selenide Ge3Sb2Se5 semiconductor material. The preparation method uses Ge3Sb4Se7 material as raw material, adds iodine as a transport agent, and obtains Ge3Sb2Se5 single-phase material through a combination of solid-state sintering and chemical vapor phase transport, providing material support for its physical property research and functional device fabrication. Attached Figure Description

[0021] Figure 1 This is an optical microscope image of the Ge3Sb2Se5 material in Example 1.

[0022] Figure 2 The image shows the powder X-ray diffraction pattern of the Ge3Sb2Se5 material in Example 1.

[0023] Figure 3 The image shows a scanning electron microscope (SEM) image of the microstructure of the Ge3Sb2Se5 material in Example 1.

[0024] Figure 4 The image shows the X-ray energy spectrum of the Ge3Sb2Se5 material in Example 1.

[0025] Figure 5 This is an atomic resolution structural diagram of the Ge3Sb2Se5 material

[001] in Example 1, projected along the direction.

[0026] Figure 6 The image shows the powder X-ray diffraction pattern of the material prepared in Comparative Example 1.

[0027] Figure 7 This is a scanning electron microscope backscattered electron image of the material prepared in Comparative Example 1.

[0028] Figure 8 The image shows the powder X-ray diffraction pattern of the material prepared in Comparative Example 2.

[0029] Figure 9 The image shows the powder X-ray diffraction pattern of the material prepared in Comparative Example 3.

[0030] Figure 10 The powder X-ray diffraction pattern of the material prepared in Comparative Example 4 is shown. Detailed Implementation

[0031] This invention provides a layered selenide Ge3Sb2Se5 semiconductor material and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0032] This invention provides a method for preparing layered selenide Ge3Sb2Se5 semiconductor material, comprising the following steps:

[0033] S01. Grind the Ge3Sb4Se7 material and place it in a quartz tube. Add iodine particles and vacuum seal the quartz tube. Place the end of the quartz tube with the raw material in the high-temperature zone and the end without the raw material in the low-temperature zone.

[0034] S02. Heat up to 400±25℃ at the low-temperature end and 500±25℃ at the high-temperature end. After holding at this temperature for 7 days, allow the vacuum-sealed quartz tube to cool naturally to room temperature. The resulting growth material is Ge3Sb2Se5 semiconductor material.

[0035] The preparation method of this invention employs chemical vapor transport, using Ge3Sb4Se7 material as the raw material and iodine as the transport agent. Crystal growth is achieved through high-temperature dual-zone vapor transport, and the steps are simple and easy to implement. Specifically, the temperatures at the low-temperature and high-temperature ends of the preparation process cannot be too low; otherwise, the vapor transport process will not easily occur.

[0036] Preferably, the amount of iodine particles added is 4-6 mg / mL.

[0037] Preferably, the heating rate is 1-5℃ / min, and the high and low temperature ends reach the set temperature simultaneously.

[0038] Preferably, the vacuum degree of the quartz tube is ≤1 Pa.

[0039] Preferably, in step S02, after the quartz tube has naturally cooled to room temperature, the generated material is further cleaned and dried. During cleaning, the obtained material is placed in alcohol, cleaned, and dried to obtain Ge3Sb2Se5 semiconductor material.

[0040] Preferably, in step S02, the preparation method of the Ge3Sb4Se7 material includes the following steps:

[0041] A01. Using germanium powder, antimony powder, and selenium powder in a molar ratio of 3:4:7 as raw materials, the raw materials are mixed and placed in a quartz tube. Under vacuum conditions, the temperature is raised to 900-950℃ and kept at this temperature for 12-24 hours.

[0042] A02. After the heat preservation is completed, the temperature is reduced to 475-500℃ at a cooling rate of 1-5℃ / min, and then kept at this temperature for 3-5 days. After the heat preservation is completed, the material is cooled to room temperature with the furnace to obtain the Ge3Sb4Se7 material.

[0043] Preferably, in step S02, the heating rate in step A01 is 1-5℃ / min.

[0044] Preferably, in step S02, the vacuum degree of step A01 is ≤1 Pa.

[0045] The present invention will be further illustrated by the following examples and comparative examples.

[0046] Example 1

[0047] A layered selenide Ge3Sb2Se5 semiconductor material is prepared by the following steps:

[0048] Step 1: Ingredient Preparation and Packaging

[0049] Using germanium powder, antimony powder, and selenium powder with a purity of 99.99%, as raw materials, the germanium powder, antimony powder, and selenium powder in a molar ratio of 3:4:7 were weighed and mixed, placed in a quartz tube, and evacuated to ≤1Pa. Then, the quartz tube containing the sample was sealed using a flame sealing device.

[0050] Step 2: High-temperature melting and firing

[0051] The vacuum-sealed quartz tube was placed vertically in a single-temperature zone well furnace, with the tube close to the thermocouple. The temperature was increased from room temperature to 950°C at a rate of 5°C / min, and held at that temperature for 12 hours.

[0052] Step 3: Material Annealing

[0053] For the material that has been heated in step two, the temperature is reduced from 950°C to 475°C at a cooling rate of 2.5°C / min, and held at this temperature for 3 days. The vacuum-sealed quartz tube is cooled to room temperature with the furnace, and then the material is taken out from the quartz tube to obtain Ge3Sb4Se7 material with obvious layered structure.

[0054] Step 4: Grinding and Packaging

[0055] After grinding the Ge3Sb4Se7 material obtained in step three, place it in a quartz tube, add about 5 mg / mL of iodine particles, evacuate to ≤1 Pa, and then seal the quartz tube containing the sample using a flame sealing device.

[0056] Step 5: High-temperature firing in two temperature zones

[0057] The vacuum-sealed quartz tube was placed horizontally in a dual-temperature zone well furnace. The raw material was concentrated at the sealed end of the quartz tube, which was placed at the thermocouple in the high-temperature zone of the furnace. The tip of the quartz tube was placed at the thermocouple in the low-temperature zone. The temperature at the low-temperature zone was controlled at 400°C, and the temperature at the high-temperature zone was controlled at 500°C. The temperature was increased from room temperature to the specified temperature over 250 minutes and held at this temperature range for 7 days. Subsequently, the vacuum-sealed quartz tube was allowed to cool naturally to room temperature. The grown material was then placed in alcohol for cleaning and drying.

[0058] Step Six: Organization and Structure Analysis

[0059] The morphology, chemical composition, and structure of the prepared materials were analyzed and characterized using optical microscopy, X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, and transmission electron microscopy. Specific characterization results are as follows: Figures 1 to 5 As shown. The macroscopic structure of this material ( Figure 1 It has a layered morphological feature. Figure 2 This is a powder X-ray diffraction pattern. Figure 3 and Figure 4 The microstructure and atomic ratios of each element in the material were obtained using scanning electron microscopy and X-ray energy dispersive spectroscopy, respectively. Figure 5 To clarify its crystal structure using high-angle ring-shaped dark-field images obtained by electron microscopy, the above results confirm that the material obtained under these conditions is a single-phase material, and the lamellar growth direction is crystallographically... c It has an axial orientation, a chemical composition of Ge3Sb2Se5, and a crystal structure belonging to the orthorhombic crystal system.

[0060] Example 2

[0061] A layered selenide Ge3Sb2Se5 semiconductor material is prepared in a method that differs from that in Example 1 in that the temperature at the low-temperature end of the dual-temperature environment in step five is controlled at 425°C and the temperature at the high-temperature end is controlled at 525°C, and the temperature is raised from room temperature to the specified temperature in 260 minutes.

[0062] The morphology, chemical composition, and structure of the prepared material were analyzed and characterized by optical microscopy, X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, and transmission electron microscopy, respectively. It was determined that the material obtained under these conditions is a single-phase material with the chemical composition Ge3Sb2Se5.

[0063] Comparative Example 1

[0064] A material, the preparation method of which includes the following steps:

[0065] Step 1: Ingredient Preparation and Packaging

[0066] Using germanium powder, antimony powder, and selenium powder with a purity of 99.99%, 99.99%, and 99.99%, respectively, for the chemical formula Ge3Sb2Se5, germanium powder, antimony powder, and selenium powder were weighed and prepared in a molar ratio of 3:2:5. After mixing, the mixture was placed in a quartz tube, and a vacuum was drawn to ≤1Pa. Then, the quartz tube containing the sample was sealed using a flame sealing device.

[0067] Step 2: High-temperature melting and firing

[0068] The vacuum-sealed quartz tube was placed vertically in a single-temperature zone well furnace, with the tube close to the thermocouple. The temperature was increased from room temperature to 950°C at a rate of 5°C / min, and held at that temperature for 12 hours.

[0069] Step 3: Material Annealing

[0070] For the material that has been heated in step two, the temperature is reduced from 950°C to 500°C at a rate of 2.5°C / min and held at that temperature for 7 days. The vacuum-sealed quartz tube is cooled to room temperature with the furnace, and then the material is removed from the quartz tube.

[0071] Step 4: Organization and Structure Analysis

[0072] The morphology, chemical composition, and structure of the prepared material were analyzed and characterized using optical microscopy, X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectroscopy. Compared with the material obtained in Example 1, its powder X-ray diffraction pattern (…) Figure 6 The diffraction peaks in the image showed a certain shift and the appearance of other diffraction peaks (some obvious characteristic diffraction peaks are indicated by arrows); backscattered electron image ( Figure 7 The samples exhibited significant differences in atomic number contrast. Comprehensive analysis and measurement results indicate that multiple phases coexist in the obtained material, and no single-phase Ge3Sb2Se5 material was obtained. Comparative Example 1 shows that, referring to existing methods for preparing Ge3Sb4Se7 materials, it is impossible to obtain single-phase Ge3Sb2Se5 material.

[0073] Comparative Example 2

[0074] A material, the preparation method of which includes the following steps:

[0075] Step 1: Ingredient Preparation and Packaging

[0076] Using germanium powder, antimony powder, and selenium powder with a purity of 99.99%, 99.99%, and 99.99%, respectively, for the chemical formula Ge3Sb2Se5, germanium powder, antimony powder, and selenium powder in a molar ratio of 3:2:5 were weighed and mixed in a quartz tube. The tube was then evacuated to a vacuum of ≤1Pa, and subsequently sealed with a flame sealing device.

[0077] Step 2: High-temperature melting and firing

[0078] The vacuum-sealed quartz tube is placed vertically in a single-temperature zone pit furnace, with the quartz tube near the thermocouple. The temperature is increased from room temperature to 500°C at a rate of 5°C / min, and held at this temperature for 7 days. The vacuum-sealed quartz tube is then cooled to room temperature with the furnace, and the material is then removed from the quartz tube.

[0079] Step 3: Organization and Structure Analysis

[0080] The morphology, chemical composition, and structure of the prepared material were analyzed and characterized using optical microscopy, X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectroscopy. Compared with the material obtained in Example 1, its powder X-ray diffraction pattern (…) Figure 8 The diffraction peaks in the sample showed a certain shift and the appearance of other diffraction peaks (some obvious characteristic diffraction peaks are indicated by arrows). This result is similar to that of Comparative Example 1, but the content is significantly increased, indicating that multiple phases coexist in the obtained material and that Ge3Sb2Se5 single-phase material was not obtained.

[0081] Comparative Example 3

[0082] A material, the preparation method of which includes the following steps:

[0083] Step 1: Ingredient Preparation and Packaging

[0084] Using germanium powder, antimony powder, and selenium powder with a purity of 99.99%, 99.99%, and 99.99%, respectively, for the chemical formula Ge3Sb2Se5, germanium powder, antimony powder, and selenium powder in a molar ratio of 3:2:5 were weighed and mixed in a quartz tube. The tube was then evacuated to a vacuum of ≤1Pa, and subsequently sealed with a flame sealing device.

[0085] Step 2: High-temperature melting and firing

[0086] The vacuum-sealed quartz tube was placed vertically in a single-temperature zone well furnace, with the tube close to the thermocouple. The temperature was increased from room temperature to 950°C at a rate of 5°C / min, and held at that temperature for 12 hours.

[0087] Step 3: Material Annealing

[0088] For the material that has been heated in step two, the temperature is reduced from 950°C to 500°C at a rate of 2.5°C / min and held at that temperature for 7 days. The vacuum-sealed quartz tube is cooled to room temperature with the furnace, and then the material is removed from the quartz tube.

[0089] Step 4: Grinding and Packaging

[0090] After grinding the material obtained in step three, place it in a quartz tube, add about 5 mg / mL of iodine particles, evacuate to ≤1 Pa, and then seal the quartz tube containing the sample using a flame sealing device.

[0091] Step 5: High-temperature firing in two temperature zones

[0092] The vacuum-sealed quartz tube was placed horizontally in a dual-temperature zone well furnace. The raw material was concentrated at the sealed end of the quartz tube, which was placed at the thermocouple in the high-temperature zone of the furnace. The tip of the quartz tube was placed at the thermocouple in the low-temperature zone. The temperature at the low-temperature zone was controlled at 400°C, and the temperature at the high-temperature zone was controlled at 500°C. The temperature was increased from room temperature to the specified temperature over 250 minutes and held at this temperature range for 7 days. Subsequently, the vacuum-sealed quartz tube was allowed to cool naturally to room temperature. The grown material was then placed in alcohol for cleaning and drying.

[0093] Step Six: Organization and Structure Analysis

[0094] The morphology, chemical composition, and structure of the prepared material were analyzed and characterized using optical microscopy, X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectroscopy. The material prepared under these process conditions is GeSe( Figure 9 No Ge3Sb2Se5 material was obtained.

[0095] Comparative Example 4

[0096] A material, the preparation method of which includes the following steps:

[0097] Step 1: Ingredient Preparation and Packaging

[0098] Using germanium powder, antimony powder, and selenium powder with a purity of 99.99%, 99.99%, and 99.99%, respectively, for the chemical formula Ge3Sb2Se5, germanium powder, antimony powder, and selenium powder were weighed and prepared in a molar ratio of 3:2:5. After mixing, the mixture was placed in a quartz tube, and approximately 5 mg / mL of iodine particles were added. The tube was then evacuated to ≤1 Pa, and subsequently sealed with a flame sealing device.

[0099] Step 2: High-temperature firing in dual temperature zones

[0100] The vacuum-sealed quartz tube was placed horizontally in a dual-temperature zone well furnace. The raw material was concentrated at the sealed end of the quartz tube, which was placed at the thermocouple in the high-temperature zone of the furnace. The tip of the quartz tube was placed at the thermocouple in the low-temperature zone. The temperature at the low-temperature zone was controlled at 400°C, and the temperature at the high-temperature zone was controlled at 500°C. The temperature was increased from room temperature to the specified temperature over 250 minutes and held at this temperature range for 7 days. Subsequently, the vacuum-sealed quartz tube was allowed to cool naturally to room temperature. The grown material was then placed in alcohol for cleaning and drying.

[0101] Step 3: Organization and Structure Analysis

[0102] The morphology, chemical composition, and structure of the prepared material were analyzed and characterized using optical microscopy, X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectroscopy. The material prepared under these process conditions is GeSe( Figure 10The failure to obtain Ge3Sb2Se5 material indicates that, under the same experimental conditions as in Example 1, the target material could not be directly prepared by using the elemental molar ratio.

[0103] Comparative Example 5

[0104] The preparation method of a material differs from that of Example 1 in that, in step five, the temperature at the low-temperature end of the dual-temperature zone is controlled at 300°C, and the temperature at the high-temperature end is controlled at 400°C, with the temperature being raised from room temperature to the specified temperature over 200 minutes.

[0105] The results showed that no material was obtained in the low-temperature region. This may be because the temperatures in the low-temperature and high-temperature regions of this comparative example are low, making it difficult for gas phase transport processes to occur, resulting in no significant growth in the low-temperature region under these conditions.

[0106] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a layered selenide Ge3Sb2Se5 semiconductor material, characterized in that, Includes the following steps: S01. Grind the Ge3Sb4Se7 material and place it in a quartz tube. Add iodine particles and vacuum seal the quartz tube. Place the end of the quartz tube with the raw material in the high-temperature zone and the end without the raw material in the low-temperature zone. S02. Heat up to 400±25℃ at the low-temperature end and 500±25℃ at the high-temperature end. After holding at this temperature for 7 days, allow the vacuum-sealed quartz tube to cool naturally to room temperature. The resulting growth material is Ge3Sb2Se5 semiconductor material.

2. The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to claim 1, characterized in that, The amount of iodine granules added is 4–6 mg / mL.

3. The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to claim 1, characterized in that, The heating rate is 1-5℃ / min, and the high and low temperature ends reach the set temperature simultaneously.

4. The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to claim 1, characterized in that, The vacuum degree of the quartz tube is ≤1Pa.

5. The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to claim 1, characterized in that, In step S02, after the quartz tube cools naturally to room temperature, the generated material is also cleaned and dried.

6. The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to claim 1, characterized in that, The preparation method of the Ge3Sb4Se7 material includes the following steps: A01. Using germanium powder, antimony powder, and selenium powder in a molar ratio of 3:4:7 as raw materials, the raw materials are mixed and placed in a quartz tube. Under vacuum conditions, the temperature is raised to 900-950℃ and kept at this temperature for 12-24 hours. A02. After the heat preservation is completed, the temperature is reduced to 475-500℃ at a cooling rate of 1-5℃ / min, and then kept at this temperature for 3-5 days. After the heat preservation is completed, the material is cooled to room temperature with the furnace to obtain the Ge3Sb4Se7 material.

7. The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to claim 6, characterized in that, In step A01, the heating rate is 1–5 °C / min.

8. The method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to claim 6, characterized in that, In step A01, the vacuum level is ≤1 Pa.

9. A layered selenide Ge3Sb2Se5 semiconductor material, characterized in that, It is prepared by the method for preparing the layered selenide Ge3Sb2Se5 semiconductor material according to any one of claims 1-8.

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