An inorganic semiconductor material with plastic deformation capability and its preparation method
By controlling the composition in the Cu2-xQ system, Cu2-xSe inorganic semiconductor materials were synthesized. By utilizing the random migration characteristics of Cu+ ions in the FCC sublattice, the problem of easy cracking of semiconductor materials during deformation was solved, achieving compressive strain and plastic deformation capacity of more than 35%, thus expanding the application of flexible electronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INST OF METAL RESEARCH - CHINESE ACAD OF SCI
- Filing Date
- 2024-03-22
- Publication Date
- 2026-05-26
Smart Images
Figure CN118206079B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an inorganic semiconductor material with plastic deformation capability and its preparation method, belonging to the field of semiconductor materials. Background Technology
[0002] With the advancement of wearable devices and other electronic products and technologies, the demand for flexible semiconductor devices capable of withstanding certain deformations is increasing. However, the strong directional nature of the ionic bonds in semiconductor materials makes them brittle rather than ductile, leading to deformation, difficulty in processing, and a high susceptibility to cracking under stress. This increases the processing cost of semiconductor materials and severely limits their application development. The compressive strain of most existing semiconductor materials is typically below 20% or even almost nonexistent, with only a few inorganic semiconductor materials achieving compressive strains of 40% or higher.
[0003] Two-dimensional semiconductor materials, such as InSe and SnSe, exhibit excellent compressive properties along a specific crystal plane in their single-crystal state; however, their polycrystalline forms lack effective slip systems and exhibit poor plasticity. ZnS can achieve a compressive strain of 45% under dark conditions but shows almost no plasticity under light. Ag₂S, an n-type semiconductor, is a widely used thermoelectric material with compressive strain exceeding 50%, making it one of the most plastic semiconductor materials currently available. However, Ag₂S has a low carrier concentration, resulting in thermoelectric properties inferior to high-conductivity materials like Cu₂Se. Furthermore, while organic semiconductors offer superior flexibility compared to inorganic semiconductors, their performance often falls short, and their properties are relatively unstable. Therefore, finding suitable plastic semiconductor materials for different applications remains a pressing issue for the scientific community and the semiconductor industry.
[0004] The Cu₂Q (Q = S, Se, Te) system of semiconductors exhibits relatively high electrical conductivity, making it an ideal p-type thermoelectric semiconductor material. At room temperature, Cu₂Q materials typically exhibit a monoclinic or orthorhombic structure. Upon heating to a certain temperature, they transform into a face-centered cubic (FCC) superionic conductor, where anions occupy the FCC lattice structure, while Cu... + Ions are randomly distributed in the interstices of the FCC lattice. For Cu under non-stoichiometric composition... 2-x Q, when x reaches 0.2 or above, Cu 2-x Q will form a superionic conductor at room temperature. However, Cu 2-x Q exhibits poor plasticity at room temperature, limiting its application prospects. Therefore, effective preparation methods are needed to control the material structure of this system and overcome the bottleneck of the difficulty in deforming this type of semiconductor material. Summary of the Invention
[0005] To address the aforementioned problems and based on the current research status, this invention aims to provide an inorganic semiconductor material with plastic deformation capability and its preparation method, Cu 2-x A novel P-type inorganic semiconductor material with certain plasticity at room temperature was synthesized by controlling the composition in the Q system.
[0006] The technical solution of this invention is:
[0007] An inorganic semiconductor material with plastic deformation capability, wherein the inorganic semiconductor material is a Cu-based superionic conductor compound Cu. 2-x Se, 0.24≤x≤0.3. Furthermore, the inorganic semiconductor material is a single crystal or polycrystalline material, and the inorganic semiconductor material can withstand compressive strain of more than 35%.
[0008] A method for preparing an inorganic semiconductor material with plastic deformation capability includes the following steps:
[0009] (1) Using high-purity Cu powder and Se powder as raw materials, weigh out Cu powder and Se powder and control the molar ratio between the two to be between 1.7:1 and 1.76:1;
[0010] (2) The above raw materials are vacuum-sealed through a quartz tube, placed in a muffle furnace, heated to 1100℃~1300℃, held at that temperature for 10~15 hours, and then gradually cooled to room temperature to obtain the inorganic semiconductor material Cu. 2-x Se ingot casting. The holding time must be long enough to ensure the sample material is fully melted and has a uniform composition.
[0011] Furthermore, in step (1), the purity of the high-purity Cu powder and Se powder is above 99.999 wt%. The high-purity raw materials avoid plastic deformation and properties such as conductivity caused by impurity elements.
[0012] Furthermore, in step (2), the vacuum sealing process requires controlling the vacuum pressure in the quartz tube to be ≤2Pa. Sealed sealing prevents the Se powder from evaporating during melting, which could lead to inaccurate composition, the formation of other impurities, and negatively impact semiconductor performance. High vacuum requirements also prevent the introduction of impurities such as oxygen during high-temperature melting, which could form other phases, damage the purity of the semiconductor material, and affect its performance characteristics.
[0013] Furthermore, in step (2), the heating rate is 0.5℃ / min to 2℃ / min to prevent the quartz tube from cracking due to excessively rapid heating and violent reaction between Cu powder and Se powder.
[0014] Furthermore, in step (2), the cooling method is furnace cooling, and the cooling rate is 0.5℃min~1.5℃ / min, to avoid cracking or internal pores in the sample due to excessive cooling speed.
[0015] The design concept of this invention is:
[0016] Cu 2-x Q (Q = S, Se, Te) is an ideal p-type semiconductor material. Cu₂Q material has a monoclinic or orthorhombic structure at room temperature, but it transforms into a superionic conductor, namely Se, when heated to a certain temperature. 2- Occupying the FCC sublattice, while Cu + Ions randomly occupy sites within the FCC framework of anions and migrate rapidly. However, reducing the Cu content leads to a decrease in the phase transition temperature of the superionic conductor. When x reaches 0.2 or higher, the phase transition temperature drops below room temperature, forming a superionic conductor at room temperature. However, when x is too large, a Cu3Se2 phase may form. This invention aims to control the Cu content... 2-x Se (0.24 ≤ x ≤ 0.3) forms Cu at room temperature. 2-x Se superionic conductor, utilizing Cu + The ability to migrate randomly and rapidly compensates for the strong directionality of the Cu-Se ionic bond, which is unfavorable for dislocation slip, thereby promoting Se... 2- The slippage of the FCC sublattice enhances its plasticity.
[0017] The advantages and beneficial effects of this invention are:
[0018] The inorganic semiconductor material described in this invention can withstand more than 35% compressive strain and has a certain plastic deformation capability, further expanding the limited types of plastic semiconductor materials and providing a solution to overcome the poor plasticity of semiconductor materials and the development of flexible electronic devices. Attached Figure Description
[0019] Figure 1 This is a flowchart illustrating the specific operation of synthesizing and testing the constituent material according to the present invention.
[0020] Figure 2 This is the X-ray diffraction (XRD) pattern of the sample in the example. In the figure, the horizontal axis 2theta represents the diffraction angle (°), and the vertical axis Intensity represents the relative intensity.
[0021] Figure 3 These are bright-field transmission electron microscope images of the samples in the examples.
[0022] Figure 4 This is a comparison diagram of the compressed sample and the uncompressed sample of the present invention. The left side shows the sample after 40% compression, and the right side shows the uncompressed sample with length, width, and height of 5mm, 5mm, and 10mm, respectively.
[0023] Figure 5This is a comparison of the compressive stress-strain curves of the embodiments and several other inorganic semiconductor materials. In the figure, the horizontal axis represents compressive strain (%), and the vertical axis represents compressive stress (MPa). Detailed Implementation
[0024] In the specific implementation process, in view of the current lack of P-type plastic semiconductor materials, this invention decides to use Cu... 2- x The Q system attempts to address this issue through component regulation.
[0025] The present invention provides an inorganic semiconductor material with plastic deformation capability, comprising a superionic conductor compound with the composition shown in formula (1) below.
[0026] Cu 2-x Se(1)
[0027] Where 0.24≤x≤0.3.
[0028] The inorganic semiconductor material of the present invention has a certain plastic deformation capability, which further expands the limited types of plastic semiconductor materials and provides a solution to overcome the problems of poor plasticity of semiconductor materials and the development of flexible electronic devices.
[0029] The inorganic semiconductor material can withstand compressive strain of more than 35%.
[0030] The inorganic semiconductor material can be polycrystalline, meaning that the material is composed of many grains with different orientations.
[0031] The inorganic semiconductor material can also be a single crystal, that is, the material is composed of a single grain.
[0032] In addition, the present invention provides a specific method for synthesizing the plastic semiconductor material, comprising the following steps:
[0033] First, Cu powder and Se powder with a purity of 99.99 wt% or higher were weighed out as initial raw materials at a molar ratio of 1.7:1 to 1.76:1 and sealed. Then, a vacuum treatment was performed, involving three evacuation cycles. After the first two evacuations, argon gas was introduced to purge the tubes.
[0034] Then, the polycrystalline preparation process is carried out. First, the sealed quartz tube is placed in a muffle furnace and heated to 1100℃~1300℃ at a slow heating rate of 0.5℃ / min~2℃ / min. Then, it is held at this temperature for 10~15 hours to allow the initial raw materials to completely melt and mix evenly. Subsequently, the sample is allowed to cool in the quartz tube along with the furnace to room temperature after 1000~1800 minutes, obtaining the initial polycrystalline ingot.
[0035] The obtained ingot was cut, and no holes were found on the surface and cross-section of the ingot during the cutting process, indicating that the ingot prepared by this process and parameters has a relatively dense texture.
[0036] The present invention will be further described below with reference to the accompanying drawings and specific operation examples. The following operation description is only for explaining the present invention and not for limiting the present invention.
[0037] Example 1
[0038] like Figure 1 As shown, Cu powder and Se powder with a purity of 99.99 wt% or higher were weighed out as initial raw materials at a molar ratio of 1.73:1, totaling 14 g. These were mixed in a quartz tube with an inner diameter of 16.5 mm and then sealed. Vacuum treatment was then performed, with the sealed quartz tube evacuated three times, each time for 10 minutes. After the first two evacuations, argon gas was introduced to clean the quartz tube. The sealed quartz tube was then placed in a muffle furnace, and the temperature was slowly increased to 1165°C over approximately 1200 minutes. This temperature was then maintained for 14 hours to ensure complete melting and homogeneous mixing of the initial raw materials. The sample was then allowed to cool in the quartz tube along with the furnace, reaching room temperature after approximately 1500 minutes, yielding the initial Cu. 2-x The Se polycrystalline ingot was shaped like a disc with a slightly raised center on the upper surface and a diameter of approximately 16.3 mm. After slightly polishing the surface of the ingot, it was cut using a diamond wire cutter at a cutting speed of 0.5 mm / min to produce cuboid polycrystalline pillars with dimensions of 5 mm in length, 5 mm in width, and 10 mm in height. No pores were observed on the surface or cross-section of the ingot during the cutting process, indicating that the ingot prepared using this process and parameters has a relatively dense texture. Finally, the compressive stress-strain curve of the cut polycrystalline cubic pillars was tested using a universal testing machine, revealing that the prepared Cu... 1.73 Se materials possess a certain degree of plastic deformation capability, reaching a compressive strain of 40%. (See...) Figure 4 as well as Figure 5 Curve 1 and Curve 2.
[0039] like Figure 2 As shown in the figure, the X-ray diffraction (XRD) pattern of the sample in the example shows that the prepared sample has a pure face-centered cubic structure and no impurity peaks of other phases are generated, indicating that the prepared sample is a pure FCC phase.
[0040] like Figure 3 As shown in the transmission electron microscope bright-field phase photographs of the samples in the examples, apart from the diffraction contrast caused by slight crystal orientation differences, there is no second phase precipitation contrast, indicating that the prepared samples are relatively pure.
[0041] Comparative Example 1
[0042] like Figure 1 As shown, Cu powder and Se powder with a purity of 99.99 wt% or higher were weighed out as initial raw materials at a molar ratio of 1.77:1, totaling 14 g. These were mixed in a quartz tube with an inner diameter of 16.5 mm and then sealed. Vacuum treatment was then performed, with the sealed quartz tube evacuated three times, each time for 10 minutes. After the first two evacuations, argon gas was introduced to clean the quartz tube. The sealed quartz tube was then placed in a muffle furnace and slowly heated to 1165°C over approximately 1200 minutes. This temperature was then maintained for 14 hours to ensure complete melting and homogeneous mixing of the initial raw materials. The sample was then allowed to cool in the quartz tube along with the furnace, reaching room temperature after approximately 1500 minutes, yielding the initial Cu. 2-x The Se polycrystalline ingot was shaped like a disc with a slightly raised center on the upper surface and a diameter of approximately 16.3 mm. After slightly polishing the surface of the ingot, it was cut using a diamond wire cutter at a cutting speed of 0.5 mm / min to produce cuboid polycrystalline pillars with dimensions of 5 mm in length, 5 mm in width, and 10 mm in height. No pores were observed on the surface or cross-section of the ingot during the cutting process, indicating that the ingot prepared using this process and parameters has a relatively dense texture. Finally, the compressive stress-strain curve of the cut polycrystalline cubic pillars was tested using a universal testing machine, revealing that the prepared Cu... 1.77 Se materials possess a certain degree of plastic deformation capability, but only about 14%, see [link to article]. Figure 5 Medium curve 5.
[0043] like Figure 5 As shown in curve 3, AgI has a plastic deformation capacity of only 2%, which is almost non-existent.
[0044] like Figure 5 As shown in curve 4, CuI has a plastic deformation capacity of approximately 19%, indicating some plastic deformation capacity, but less than that of Cu mentioned in the previous case. 1.73 40% compressive strain of Se.
[0045] The results show that the method of the present invention is simple and produces inorganic semiconductors with high plasticity and compressive strain of more than 35%.
Claims
1. A method for preparing an inorganic semiconductor material with plastic deformation capability, characterized in that, Inorganic semiconductor materials are Cu-based superionic conductor compounds. 2-x Se, 0.27 ≤ x ≤ 0.3; The method for preparing the inorganic semiconductor material with plastic deformation capability includes the following steps: (1) Using high-purity Cu powder and Se powder as raw materials, weigh out Cu powder and Se powder and control the molar ratio between them to be between 1.7:1 and 1.73:1; (2) The above raw materials were vacuum-sealed through a quartz tube and placed in a muffle furnace. The temperature was increased to 1100℃~1300℃ at a heating rate of 0.5℃ / min~2℃ / min, held for 10~15 hours, and then cooled to room temperature. The cooling method was furnace cooling at a rate of 0.5℃ / min~1.5℃ / min to obtain the inorganic semiconductor material Cu. 2-x Se, an inorganic semiconductor material, can withstand more than 35% compressive strain.
2. The method for preparing an inorganic semiconductor material with plastic deformation capability as described in claim 1, characterized in that, Inorganic semiconductor materials can be single crystals or polycrystalline.
3. The method for preparing an inorganic semiconductor material with plastic deformation capability as described in claim 1, characterized in that, In step (2), the vacuum sealing process requires controlling the vacuum pressure in the quartz tube to be below 2 Pa.