Zinc telluride target material containing doping elements and preparation method thereof

Abstract

The invention relates to the technical field of target material preparation, and discloses a doped element-containing zinc telluride target material, which comprises the following components by weight: 10-15 parts of a zinc source; 7-10 parts of a tellurium source; 1.5 to 3.0 parts of an indium source; 0.2 to 2.5 parts of a sulfur source; 1.2 to 1.8 parts of a boron and nitrogen co-doped carbon nano tube; 0.5 to 1.0 part of polydopamine; the invention further provides a preparation method of the zinc telluride target material containing the doping elements. The preparation method comprises the following steps: S1, preparing a precursor solution; s2, performing microwave-assisted reaction to synthesize a precursor of the zinc telluride target material; s3, separating, washing and drying the reaction product; and S4, compression molding and hot isostatic pressing treatment are carried out, and the target material is obtained. According to the preparation method disclosed by the invention, a collaborative construction mechanism of the BN-CNTs and the PDA is introduced, so that high densification and interface homogenization treatment of the structure are realized, and finally the zinc telluride target material with high mechanical strength and low resistivity is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of target material preparation, and in particular to a zinc telluride target material containing doping elements and a preparation method thereof. Background Art

[0002] With the development of flexible electronics, low-temperature sputtering processes and new transparent conductive films, the requirements for high-performance metal oxide and metal compound targets are constantly increasing. Zinc telluride (ZnTe) has been widely used in thin-film solar cells, infrared detectors, sensors and other fields due to its excellent optoelectronic properties and semiconductor properties. In order to further improve the conductivity, density and film stability of the target material, the industry has begun to turn to composite control strategies such as multi-element doping, structural optimization and interface engineering.

[0003] At present, some studies have adjusted the electrical properties of ZnTe by introducing heterogeneous doping elements such as indium and sulfur, and combined with simple microwave synthesis technology to achieve preliminary low-temperature preparation and grain control. In addition, there are also technologies that try to add nanocarbon materials to improve the conductivity and some mechanical properties of the target material. Under experimental conditions, good film uniformity and conductive path expansion are achieved. Some methods also use solution method combined with traditional cold pressing process, which has certain advantages in cost and process compatibility, is suitable for small-batch targeted development, and has certain practical value.

[0004] However, these methods still have obvious shortcomings in structural control and doping distribution. In most processes, the enrichment behavior of doping elements lacks a guiding mechanism, which is prone to local segregation. In particular, sulfur, due to its high volatility, often migrates during the heat treatment stage, resulting in insufficient internal doping. Some methods attempt to improve uniformity by extending the stirring time or increasing the temperature, but the reaction process lacks control measures, and the doping effect is limited. In terms of structural density, single cold pressing cannot compact the pores between particles, and cracking or grain coarsening is easy to form during heat treatment. Some studies have introduced nano-reinforced materials, but lack interface control measures, resulting in serious agglomeration between particles, which ultimately reduces the mechanical properties. To this end, those skilled in the art have proposed a zinc telluride target containing doping elements and a preparation method thereof to solve the above problems. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a zinc telluride target material containing doping elements and a preparation method thereof, which solves the problems of uneven doping distribution, loose structure and poor sputtering stability in the existing technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a zinc telluride target containing doping elements, comprising the following components in parts by weight:

[0007] Zinc source: 10-15 parts;

[0008] Tellurium source: 7-10 parts;

[0009] Indium source: 1.5-3.0 parts;

[0010] Sulfur source: 0.2-2.5 parts;

[0011] Boron and nitrogen co-doped carbon nanotubes: 1.2-1.8 parts;

[0012] Polydopamine: 0.5-1.0 parts;

[0013] In the target material, the doping elements indium and sulfur are evenly distributed in the target material to form a concentration gradient distribution, wherein the indium element is enriched on the surface of the target material and the sulfur element forms a gradient distribution inside the target material.

[0014] The target material is composed of a Zn source (zinc acetate, Zn(CH3COO)2), a Te source (sodium tellurite, Na2TeO3), an In source (indium chloride, InCl3), a S source (thiourea, SC(NH2)2), boron-nitrogen co-doped carbon nanotubes (BN-CNTs), and polydopamine (PDA). A notable feature of this formulation is the introduction of indium and sulfur as dual dopants into the base ZnTe compound system, with indium being concentrated on the surface and sulfur forming a gradient distribution that decreases from the outside inward.

[0015] This distribution structure can effectively adjust the carrier concentration and distribution state in the target material. 3+ The introduction of can replace Zn in the lattice 2+ The introduction of free electrons is beneficial to improving n-type conductivity; while S 2- Doping can replace Te 2- The site is enriched at a shallow energy level, further optimizing the band structure and suppressing the generation of intrinsic defects. Through differential enrichment of spatial positions, the problems of band disorder and interface mismatch caused by conventional doping are solved, thereby improving the consistency of the target material and the film quality in magnetron sputtering applications.

[0016] Preferably, the zinc source is zinc acetate, the tellurium source is sodium tellurite, the indium source is indium chloride, and the sulfur source is thiourea.

[0017] Zinc acetate, sodium tellurite, indium chloride, and thiourea not only have good solubility and reactivity, but also ensure the uniform release and complexation of Zn, Te, In, and S during the reaction. Zinc acetate is a weak acid and weak base salt. 2+ The ion release process is smooth, which is conducive to the formation of uniform crystal nuclei; Te in sodium tellurite 4+ Easy to reduce to Te during heating 2- , which helps with Zn 2+ Forming ZnTe precursor; Indium chloride forms [In(H2O)6] in solution3+ complex state, which is convenient for surface doping; thiourea decomposes in the microwave field to release S 2- , and its release rate is slow, which is conducive to the formation of internal gradient.

[0018] Preferably, the surface layer of the target material contains an indium-enriched area, and the indium concentration is 2-4 times that of the interior of the target material; the interior of the target material is a sulfur-doped gradient area, and the sulfur concentration gradually decreases from the surface to the inside, and the sulfur concentration is not less than 0.2%.

[0019] The surface indium-rich area and internal sulfur-doped gradient area of the target are essentially designed based on the differences in diffusion kinetics and reaction paths. Since the decomposition products of indium chloride tend to nucleate and deposit on the outer layer of the material, and the S released by thiourea 2- It is easier to diffuse into the interior of the material in the form of small molecules, thus forming a doping structure with controllable spatial distribution.

[0020] This structure achieves the coordinated optimization of energy band regulation and carrier behavior. The surface In-rich region improves the surface electron mobility, which is beneficial to the stability of electron density during sputtering; the internal gradient doping S controls the energy level gradient, suppresses charge recombination, and improves the consistency and electrical uniformity of device film formation.

[0021] Preferably, the target material has a density of more than 95%, and its crystal structure is stable, with no obvious cracks and pores on the surface.

[0022] Through multi-component collaborative optimization, a ZnTe target with a density of over 95% was obtained, and the material has a regular crystal structure and no cracks on the surface. This is mainly due to the introduction of BN-CNTs and PDA. BN-CNTs, due to its high specific surface area and high modulus, acts as a skeleton support and flow channel between particles, effectively promoting particle rearrangement and interface bonding during the molding process; PDA can form an organic-inorganic interface layer during the reaction process, improving the degree of densification and preventing excessive grain growth. The two work together in the sintering and densification process to construct a target with stable mechanical properties and continuous structure.

[0023] A method for preparing a zinc telluride target containing a doping element comprises the following steps:

[0024] S1. Prepare precursor solution;

[0025] S2. performing a microwave-assisted reaction to synthesize a precursor of a zinc telluride target;

[0026] S3, separating, washing and drying the reaction product;

[0027] S4. Pressing and hot isostatic pressing are performed to obtain a dense zinc telluride target.

[0028] The preparation method utilizes four steps: precursor solution preparation, microwave-assisted reaction, drying, and hot isostatic pressing (HIP), achieving full control over the entire conversion process from solution to solid target. Unlike traditional solid-phase sintering, this approach emphasizes precise control of liquid phase dispersion uniformity and energy input. In particular, the combination of microwave-assisted reaction and HIP avoids particle agglomeration and interfacial stress accumulation, significantly improving the density and compositional uniformity of the final target. This four-step synergistic mechanism forms a continuous and controllable chain of phase generation and microstructure regulation.

[0029] Preferably, the preparation of the precursor solution comprises:

[0030] Add 10-15 parts of zinc acetate, a zinc source, to a mixed solvent of ethylene glycol and deionized water in a volume ratio of 3:1 to 5:1, and stir for 20-40 minutes until the zinc source is completely dissolved;

[0031] Add 7-10 parts of sodium tellurite, a tellurium source, to the above solution and continue stirring for 20-40 minutes until the tellurium source is completely dissolved;

[0032] According to the desired doping ratio, add 1.5-3.0 parts of indium chloride as the indium source and 0.2-2.5 parts of thiourea as the sulfur source, and continue stirring for 20-40 minutes to ensure that the doping elements are evenly dispersed;

[0033] Add 1.2-1.8 parts of boron-nitrogen co-doped carbon nanotubes as a template, and use an ultrasonic cleaner to perform ultrasonic treatment for 30-50 minutes at a frequency of 38-42 kHz and a power of 450-550 W to uniformly disperse the carbon nanotubes;

[0034] Dissolve 0.5-1.0 parts of polydopamine in ethylene glycol, adjust the pH of the solution to 8.0-9.0, and stir for 20-40 minutes to form a stable PDA solution;

[0035] All the above solutions were mixed and stirred for 0.5-1.5 hours to obtain a uniform precursor solution.

[0036] The components in the precursor solution are rationally matched through solvent selection (ethylene glycol / water) and complexation sequence to ensure the stable existence of the complex state of the reaction precursor. Zinc acetate and sodium tellurite first form the ZnTe complex group, followed by InCl3 and SC(NH2)2 added in dissolved and complexed forms, respectively, to ensure the uniform distribution of the doping ions. BN-CNTs are dispersed in an ultrasonic field, and PDA forms a stable colloidal system through a pH-induced polymerization process. This highly uniform liquid phase system lays the foundation for the formation of micro-nanostructures in subsequent reactions, inhibits the loss of particle size control, and facilitates the formation of a uniform sintered body.

[0037] Preferably, the microwave-assisted reaction comprises:

[0038] Transfer the prepared precursor solution to a polytetrafluoroethylene-lined autoclave;

[0039] Heating is carried out at a microwave power of 700-900W and a frequency of 2.40-2.50GHz, and is divided into two stages:

[0040] The first stage is intermittent heating;

[0041] The second stage is continuous heating;

[0042] After the reaction is completed, the reactor is naturally cooled to 40-60°C at a cooling rate of 3-7°C / min.

[0043] During the microwave-assisted reaction, an 800W, 2.45GHz microwave field heats the system in two stages. The first stage is intermittent, inducing a slow temperature rise and nucleation; the second stage is continuous heating, promoting uniform grain growth. The selective coupling effect of microwaves encourages reactants to absorb energy at specific sites, stimulating non-thermal effects (such as electron cloud reconstruction and transient diffusion), thereby increasing the reaction rate and uniformity. The natural cooling process controls stress release in the crystal and inhibits crack formation.

[0044] Preferably, the steps of separation, washing and drying include:

[0045] The reaction products were separated by centrifugation at a speed of 7500-8500 rpm for 8-12 minutes;

[0046] Wash with deionized water and anhydrous ethanol alternately 2-4 times to remove unreacted substances;

[0047] The separated solid product is placed in a vacuum drying oven at a temperature of 55-65° C. for 10-14 hours.

[0048] The combined treatment of centrifugation, alternating washing, and vacuum drying not only effectively removes residual reaction byproducts but also induces weak bonding between nanoparticles through intermolecular forces, providing a highly plastic powder for compaction. The vacuum drying process prevents oxidation and impurity adsorption, making it a crucial step in controlling target purity.

[0049] Preferably, the compression molding comprises:

[0050] The dried product is placed into a mold and cold pressed at a pressure of 100-200 MPa;

[0051] The holding time is 5-15 minutes;

[0052] The pressed product is subjected to hot isostatic pressing treatment at a temperature of 350-450° C., a pressure of 120-180 MPa, and a holding time of 1-3 hours.

[0053] The cold pressing process achieves initial structural definition, with pressure controlled within the 100–200 MPa range, effectively controlling the initial porosity. The hot isostatic pressing process achieves densification sintering at 350–450°C and 120–180 MPa. This process, under three-dimensional isotropic pressure, promotes defect-free fusion between grains and improves mechanical integrity. This strategy overcomes the uneven porosity shrinkage inherent in traditional sintering, resulting in a highly dense, high-strength target.

[0054] Preferably, the intermittent microwave heating mode is heating for 8-12 seconds each time, with an interval of 4-6 seconds, a heating temperature of 110-130°C, and a heating time of 25-35 minutes; the temperature of the continuous microwave heating mode is raised to 170-190°C, and the heating time is 25-35 minutes; wherein the temperature fluctuation during the entire reaction process does not exceed ±2°C.

[0055] The intermittent heating mode (10 seconds on / 5 seconds off) allows the reaction system to form periodic energy fluctuations in the microwave field, promoting selective nucleation growth and inhibiting agglomeration. The continuous heating mode provides stable thermal conditions, ensuring the growth of reactant crystals to a uniform size. The temperature is controlled within a fluctuation range of ±2°C, effectively improving the integrity of the crystal structure and the consistency of the particle size distribution.

[0056] The present invention provides a zinc telluride target material containing doping elements and a preparation method thereof. It has the following beneficial effects:

[0057] 1. The present invention achieves highly densified structure and interface homogenization by introducing the synergistic construction mechanism of BN-CNTs and PDA, ultimately obtaining a zinc telluride target with high mechanical strength and low resistivity. Compared with the preparation scheme in the prior art that does not introduce a synergistic template system and cannot effectively avoid the problems of particle agglomeration and pore formation, this technical solution effectively solves the problems of structural instability and low target performance.

[0058] 2. The present invention designs a two-stage microwave heating strategy, which first performs intermittent heating to achieve uniform nucleation of particles, and then strengthens the reaction kinetics through continuous heating to ensure reaction depth and product consistency. Compared with the traditional uniform heating method, it achieves an essential breakthrough in heat conduction uniformity and reaction control, avoiding structural defects caused by local overheating or insufficient reaction.

[0059] 3. The present invention adopts a gradient doping strategy, with indium enriched on the surface and sulfur distributed inside, to construct a dual-balance structure of electron transport path and lattice stability. This method is different from the simple doping mixing scheme in the prior art. It not only improves the electron migration efficiency, but also enhances the thermal stability of the crystal structure, overcoming the common problems of easy cracking of the film layer and poor conductivity of the target material.

[0060] 4. The low-temperature hot isostatic pressing combined with the cold pressing forming process adopted in the present invention significantly reduces the processing stress and structural defect density while ensuring density. Compared with the traditional method of direct sintering after cold pressing or high-temperature isostatic pressing, it avoids the risks of abnormal grain growth and interface embrittlement, and significantly improves the mechanical strength and sputtering uniformity of the final target material, meeting the industrial-grade preparation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic flow chart of the preparation method of the present invention. DETAILED DESCRIPTION

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0063] Please see the attached Figure 1 .

[0064] Example 1:

[0065] Raw material ratio (by weight):

[0066] Zinc source (zinc acetate): 12.5 parts; tellurium source (sodium tellurite): 9.0 parts; indium source (indium chloride): 2.0 parts; sulfur source (thiourea): 1.0 parts; BN-CNTs: 1.5 parts; polydopamine (PDA): 0.8 parts; mixed solvent: ethylene glycol: deionized water = 4:1 (volume ratio).

[0067] Preparation steps:

[0068] 1. Solution preparation:

[0069] Zinc acetate, sodium tellurite, indium chloride, and thiourea were added to a high-purity solvent, ethylene glycol, and magnetic stirring (300 rpm) was performed to ensure complete dissolution.

[0070] Appropriate amounts of BN-CNTs (1.5 parts) and polydopamine (0.8 parts) were added, and stirring was continued for 30 minutes to form a homogeneous solution.

[0071] 2. Ultrasonic dispersion:

[0072] The solution was placed in an ultrasonic cleaning machine and ultrasonicated for 45 min with the ultrasonic frequency set to 40 kHz and the power to 500 W to ensure that the precursor particles were evenly dispersed.

[0073] 3. Microwave-assisted synthesis:

[0074] The treated solution was transferred to a microwave reactor, and the reaction temperature was set at 120° C., the power was 800 W, and an intermittent heating mode (10 seconds heating, 5 seconds pause) was adopted, and the reaction time was 30 minutes.

[0075] 4. Centrifugal separation:

[0076] After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 minutes to separate the precipitate.

[0077] The reaction mixture was washed with deionized water three times to remove excess solvent and unreacted products.

[0078] 5. Vacuum drying:

[0079] The washed precipitate was placed in a vacuum drying oven, set at 60°C, and dried for 12 hours.

[0080] 6. Target forming:

[0081] The dried powder was cold pressed at a pressing pressure of 150 MPa.

[0082] Then, hot isostatic pressing treatment is performed at a temperature of 450°C and a pressure of 150 MPa for 2 hours to complete the target molding.

[0083] Example 2:

[0084] Raw material ratio (by weight):

[0085] Zinc source: 10 parts; tellurium source: 8 parts; indium source: 3.0 parts; sulfur source: 2.5 parts; BN-CNTs: 1.5 parts; polydopamine: 1.0 part; solvent: ethylene glycol: water = 4:1 (volume ratio).

[0086] Preparation steps:

[0087] 1. Solution preparation:

[0088] Dissolve zinc acetate, sodium tellurite and indium chloride in ethylene glycol, add an appropriate amount of thiourea, mix and stir evenly.

[0089] BN-CNTs and polydopamine were added and stirred for 30 min to ensure the precursor was homogeneous.

[0090] 2. Ultrasonic treatment:

[0091] Use an ultrasonic cleaning machine to ultrasonically disperse the solution, set the ultrasonic frequency to 40 kHz, the power to 500 W, and continue the treatment for 45 minutes to ensure uniform dispersion.

[0092] 3. Microwave synthesis reaction:

[0093] The solution was placed in a microwave reactor, and the power was set to 800 W, the temperature was set to 180° C., and an intermittent heating mode (12 seconds heating, 5 seconds pause) was adopted. The total reaction time was 35 minutes.

[0094] 4. Centrifugation and washing:

[0095] After the reaction, the reaction product was transferred to a centrifuge tube, centrifuged at 8000 rpm for 10 minutes, and the solution was removed.

[0096] Wash with deionized water three times to ensure complete removal of impurities.

[0097] 5. Vacuum drying:

[0098] The precipitate after centrifugation was placed in a vacuum drying oven, set at 60°C, and dried for 12 hours.

[0099] 6. Target forming:

[0100] The dried powder was pressed using a cold press at 150 MPa.

[0101] Then, hot isostatic pressing (HIP) was performed at 450 °C and a pressure of 180 MPa for 3 hours.

[0102] Example 3:

[0103] Raw material ratio (by weight):

[0104] Zinc source: 15 parts; tellurium source: 10 parts; indium source: 1.5 parts; sulfur source: 0.2 parts; BN-CNTs: 1.2 parts; polydopamine: 0.5 parts; solvent: ethylene glycol: water = 4:1 (volume ratio).

[0105] Preparation steps:

[0106] 1. Solution preparation:

[0107] Add zinc acetate, sodium tellurite, indium chloride and thiourea to ethylene glycol and stir well.

[0108] Add BN-CNTs and polydopamine and continue stirring for 30 minutes to allow them to be fully mixed.

[0109] 2. Ultrasonic dispersion:

[0110] The solution was placed in an ultrasonic cleaning machine for ultrasonic treatment. The ultrasonic frequency was set to 40 kHz, the power was 500 W, and the treatment time was 30 minutes to ensure that the substance was evenly dispersed.

[0111] 3. Microwave heating reaction:

[0112] The treated solution was placed in a microwave reactor, the power was set to 800 W, the reaction temperature was set to 170° C., an intermittent heating mode was adopted (heating for 20 seconds each time, intermittent for 5 seconds), and the total reaction time was 25 minutes.

[0113] 4. Centrifugation and washing:

[0114] After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 minutes to separate the precipitate.

[0115] Wash with deionized water three times to remove unreacted residues.

[0116] 5. Vacuum drying:

[0117] The washed precipitate was placed in a vacuum drying oven, set at 60°C, and dried for 12 hours.

[0118] 6. Target forming:

[0119] The dried powder was cold pressed at a pressure of 150 MPa.

[0120] Then, hot isostatic pressing was performed at 350°C with a pressure of 120 MPa for 1.5 hours.

[0121] Comparative Example 1: Compared with Example 1, the difference is that the BN-CNTs component is removed, and the rest are the same.

[0122] Comparative Example 2: Compared with Example 1, the difference is that the polydopamine (PDA) component is removed, and the rest are the same.

[0123] Comparative Example 3: Compared with Example 2, the difference is that the sulfur source (thiourea) component is removed, and the rest are the same.

[0124] Comparative Example 4: Compared with Example 2, the difference is that the microwave heating stage is cancelled (the traditional heating method is used instead), and the rest are the same.

[0125] Comparative Example 5: Compared with Example 3, the difference is that the BN-CNTs component is removed and the polydopamine content is reduced to 0.2 parts, and the rest are the same.

[0126] Comparative Example 6: Compared with Example 3, the difference is that the hot isostatic pressing treatment is cancelled and only cold pressing is performed, and the rest are the same.

[0127] Experiment 1:

[0128] Purpose of the experiment:

[0129] Evaluate the key roles of BN-CNTs and PDA in target performance optimization.

[0130] Experimental group:

[0131] Example 1; Comparative Example 1: Removal of BN-CNTs; Comparative Example 2: Removal of PDA.

[0132] Experimental steps:

[0133] 1. Density test:

[0134] The Archimedes method was used to determine the ratio of the target's bulk density to its theoretical density and calculate its density. During the test, three samples were randomly selected from each group for testing, and the average value was taken.

[0135] 2. Resistivity test:

[0136] The four-probe test method was used to measure the resistivity of the target surface at room temperature. The test positions were distributed at the center and edge of the sample, and the average value of multiple points was taken.

[0137] 3. Surface microstructure observation:

[0138] Scanning electron microscopy (SEM) was used to observe the surface and cross-sectional morphology of the target material and evaluate the uniformity of particle distribution and pore defects.

[0139] 4. Mechanical strength test:

[0140] The bending strength of the target was measured using a three-point bending test method. The test parameters included a span of 20 mm and a loading rate of 0.5 mm / min (the experimental data results are shown in Table 1).

[0141] Table 1: Comparative experimental test results of Example 1 and Comparative Examples 1 and 2

[0142]

[0143] From Table 1, we can get:

[0144] Experimental results show that the addition of BN-CNTs significantly improves the density and mechanical strength of the target material. This is because BN-CNTs, as a reinforcing phase, fill the particle interface and effectively inhibit the formation of pores between particles. At the same time, due to their good conductivity and spatial distribution, they facilitate the rapid migration of electrons within the material, reducing the overall resistivity. After removing the BN-CNTs from Comparative Example 1, the internal pores of the target material increased significantly, indicating that BN-CNTs play a key role in filling defects and building a uniform structure.

[0145] Furthermore, the presence of PDA plays a crucial role in regulating the dispersion of the precursor and the particle interface. Its surface adhesion properties maintain a well-dispersed state during solution synthesis and subsequent molding, reducing the risk of particle agglomeration. After removing PDA from Comparative Example 2, SEM images show localized particle agglomeration and porosity, demonstrating the irreplaceable role of PDA in regulating the interface and achieving uniform distribution of reactants.

[0146] The present invention significantly enhances the density and mechanical strength of the target material on a macroscopic level through the synergistic effect of BN-CNTs and PDA, while suppressing interparticle porosity and agglomeration on a microscopic level, thereby optimizing the overall microstructure. This not only improves the target material's physical properties but also ensures target stability and film quality during the subsequent sputtering process. This mechanism fully demonstrates the innovative nature and technical advantages of the present invention.

[0147] Experiment 2:

[0148] Purpose of the experiment:

[0149] Verify the regulatory effect and necessity of sulfur source (thiourea) and microwave heating on the performance of high-indium and high-sulfur doped targets.

[0150] Experimental group:

[0151] Example 2; Comparative Example 3: removing the sulfur source thiourea; Comparative Example 4: canceling microwave heating.

[0152] Experimental steps:

[0153] 1. Density test:

[0154] The actual density of the target material was determined using the Archimedes method and compared with the theoretical density to calculate the density. Three samples were tested independently for each group and the average value was taken.

[0155] 2. Resistivity test:

[0156] The resistivity was measured at room temperature using a four-probe test method. Measurements were made at different locations (center and edge) of the target, and the average value was taken.

[0157] 3. Phase composition and microstructure analysis:

[0158] X-ray diffraction (XRD) is used to analyze the phase composition of the target material to determine the presence of doping elements and changes in crystallinity. Scanning electron microscopy (SEM) is also used to observe the surface morphology and porosity.

[0159] 4. Physical properties and surface quality test:

[0160] The surface integrity and flatness of the target were observed visually and microscopically, and defects were recorded. The bending strength of the target was measured and the mechanical properties were evaluated (the experimental data results are shown in Table 2).

[0161] Table 2: Comparative experimental test results of Example 2 and Comparative Examples 3 and 4

[0162]

[0163] From Table 2, we can get:

[0164] The experimental results clearly show that the presence of a sulfur source (thiourea) plays a key role in the structural density and electrical conductivity of the target. During the synthesis process, sulfur effectively regulates the distribution of metal ions in the crystal lattice, promotes coordination between elements, and prevents lattice defects caused by large differences in ionic radius. After removing thiourea from Comparative Example 3, XRD results show a decrease in crystallinity, coarse grains, and insufficient sulfur doping, further leading to a significant decrease in the target's electrical conductivity and mechanical properties, and an increase in internal pores and cracks.

[0165] Microwave heating plays a crucial role in energy input and reaction acceleration during rapid material prototyping. The intermittent microwave heating employed in the present invention allows for rapid temperature increases and uniform diffusion within the system, promoting uniform reaction of the precursors and efficient incorporation of doping elements. In Comparative Example 4, after microwave heating was eliminated, XRD results revealed uneven doping and a significant decrease in crystallinity. SEM observations also revealed irregular surface pores, indicating that conventional heating methods result in insufficient energy input and uneven heat conduction, impacting the overall uniformity of the reaction process and target quality.

[0166] Overall, the present invention significantly improves the material's microstructure and physical properties through the dual regulation of sulfur doping and microwave energy input. The rational introduction of sulfur improves lattice stability and conductivity while effectively reducing internal defects. The microwave-assisted synthesis process further ensures efficient and uniform reaction, promoting rapid material formation and density improvement. The synergistic effect of these two factors constitutes the core technology of the present invention's preparation process.

[0167] Experiment 3:

[0168] Purpose of the experiment:

[0169] Verify the regulatory effect and necessity of sulfur source (thiourea) and microwave heating on the performance of high-indium and high-sulfur doped targets.

[0170] Experimental group:

[0171] Example 3; Comparative Example 5: removing BN-CNTs and reducing the PDA content; Comparative Example 6: canceling the hot isostatic pressing treatment and only cold pressing.

[0172] Experimental steps:

[0173] 1. Density test:

[0174] The Archimedes method was used to determine the ratio of the target's actual density to its theoretical density to assess its density. Three samples were selected from each group, and the average was taken.

[0175] 2. Resistivity test:

[0176] Use the four-probe test method to perform multi-point measurements at room temperature to test the resistivity of the target material and take the average value.

[0177] 3. Surface morphology and structure analysis:

[0178] Scanning electron microscopy (SEM) was used to observe the surface and cross-section of the target material to analyze the particle arrangement, pore state and interface bonding.

[0179] 4. Mechanical properties test:

[0180] The three-point bending test method was used to determine the bending strength of the target material, and the failure morphology of the sample was observed to evaluate its mechanical stability.

[0181] 5. Sputtering performance test:

[0182] In a vacuum sputtering system, sputtering experiments were carried out on each group of target materials, and the sputtering rate and film surface uniformity were recorded (the experimental data results are shown in Table 3).

[0183] Table 3: Comparative experimental test results of Example 3 and Comparative Examples 5 and 6

[0184]

[0185]

[0186] From Table 3 we can get:

[0187] Experimental results demonstrate that BN-CNTs not only reinforce the low-doped target but, more importantly, fill interfacial voids and improve particle alignment within the microstructure. The removal of BN-CNTs and the reduction in PDA content significantly reduced the density, flexural strength, and sputtering rate of Comparative Example 5 compared to Example 3, demonstrating the irreplaceable role of BN-CNTs in constructing dense and stable target structures. Their excellent flexibility and dispersibility effectively mitigate particle agglomeration and enhance overall mechanical and electrical properties.

[0188] On the other hand, hot isostatic pressing, as a typical densification method, has a decisive influence on the ultimate performance of the target material. Although cold pressing was performed after the hot isostatic pressing was eliminated in Comparative Example 6, the lack of the high-temperature and high-pressure densification process resulted in insufficient inter-particle bonding, loose interface bonding, and the formation of a relatively porous structure. SEM observations further confirmed the important role of hot isostatic pressing in improving interfacial bonding strength and density.

[0189] In a low-doping system, this invention synergistically constructs a high-strength, high-density target structure by leveraging the flexibility enhancement and interface filling effects of BN-CNTs, along with the densification and strengthening effects of hot isostatic pressing. This demonstrates excellent mechanical strength and sputtering rate at the macro level, while at the micro level, it effectively suppresses particle agglomeration, pore defects, and structural looseness, fully validating the advancement and rationality of the invention's technical solution.

[0190] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A zinc telluride target containing a doping element, characterized in that: The composition comprises the following components in parts by weight: Zinc source: 10-15 parts; Tellurium source: 7-10 parts; Indium source: 1.5-3.0 parts; Sulfur source: 0.2-2.5 parts; Boron and nitrogen co-doped carbon nanotubes: 1.2-1.8 parts; Polydopamine: 0.5-1.0 parts; In the target material, the doping elements indium and sulfur are evenly distributed in the target material to form a concentration gradient distribution, wherein the indium element is enriched on the surface of the target material and the sulfur element forms a gradient distribution inside the target material.

2. The zinc telluride target material containing doping elements according to claim 1, characterized in that: The zinc source is zinc acetate, the tellurium source is sodium tellurite, the indium source is indium chloride, and the sulfur source is thiourea.

3. The zinc telluride target material containing doping elements according to claim 1, characterized in that: The surface layer of the target material contains an indium-enriched area, and the indium concentration is 2-4 times that of the target material interior; the interior of the target material is a sulfur-doped gradient area, and the sulfur concentration gradually decreases from the surface to the inside, and the sulfur concentration is not less than 0.2%.

4. The zinc telluride target material containing doping elements according to claim 1, characterized in that: The target material has a density of more than 95%, a stable crystal structure, and no obvious cracks or pores on the surface.

5. A method for preparing a zinc telluride target containing a doping element, applied to the zinc telluride target containing a doping element according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Prepare precursor solution; S2. performing a microwave-assisted reaction to synthesize a precursor of a zinc telluride target; S3, separating, washing and drying the reaction product; S4. Pressing and hot isostatic pressing are performed to obtain a dense zinc telluride target.

6. The method for preparing a zinc telluride target containing doping elements according to claim 5, characterized in that: The preparation of the precursor solution comprises: Add 10-15 parts of zinc acetate, a zinc source, to a mixed solvent of ethylene glycol and deionized water in a volume ratio of 3:1 to 5:1, and stir for 20-40 minutes until the zinc source is completely dissolved; Add 7-10 parts of sodium tellurite, a tellurium source, to the above solution and continue stirring for 20-40 minutes until the tellurium source is completely dissolved; According to the desired doping ratio, add 1.5-3.0 parts of indium chloride as the indium source and 0.2-2.5 parts of thiourea as the sulfur source, and continue stirring for 20-40 minutes to ensure that the doping elements are evenly dispersed; Add 1.2-1.8 parts of boron-nitrogen co-doped carbon nanotubes as a template, and use an ultrasonic cleaner to perform ultrasonic treatment for 30-50 minutes at a frequency of 38-42 kHz and a power of 450-550 W to uniformly disperse the carbon nanotubes; Dissolve 0.5-1.0 parts of polydopamine in ethylene glycol, adjust the pH of the solution to 8.0-9.0, and stir for 20-40 minutes to form a stable PDA solution; All the above solutions were mixed and stirred for 0.5-1.5 hours to obtain a uniform precursor solution.

7. The method for preparing a zinc telluride target containing doping elements according to claim 5, characterized in that: The microwave-assisted reaction comprises: Transfer the prepared precursor solution to a polytetrafluoroethylene-lined autoclave; Heating is carried out at a microwave power of 700-900W and a frequency of 2.40-2.50GHz, and is divided into two stages: The first stage is intermittent heating; The second stage is continuous heating; After the reaction is completed, the reactor is naturally cooled to 40-60°C at a cooling rate of 3-7°C / min.

8. The method for preparing a zinc telluride target containing doping elements according to claim 5, characterized in that: The steps of separation, washing and drying include: The reaction products were separated by centrifugation at a speed of 7500-8500 rpm for 8-12 minutes; Wash with deionized water and anhydrous ethanol alternately 2-4 times to remove unreacted substances; The separated solid product is placed in a vacuum drying oven at a temperature of 55-65° C. for 10-14 hours.

9. The method for preparing a zinc telluride target containing doping elements according to claim 5, characterized in that: The compression molding comprises: The dried product is placed into a mold and cold pressed at a pressure of 100-200 MPa; The holding time is 5-15 minutes; The pressed product is subjected to hot isostatic pressing treatment at a temperature of 350-450° C., a pressure of 120-180 MPa, and a holding time of 1-3 hours.

10. The method for preparing a zinc telluride target containing doping elements according to claim 7, characterized in that: The intermittent microwave heating mode is to heat for 8-12 seconds each time, with an interval of 4-6 seconds, a heating temperature of 110-130°C, and a heating time of 25-35 minutes; the temperature of the continuous microwave heating mode is raised to 170-190°C, and the heating time is 25-35 minutes; wherein the temperature fluctuation during the entire reaction process does not exceed ±2°C.

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