Selenium-antimony sputtering target and method for manufacturing the same

Abstract

The application belongs to the technical field of sputtering materials for solar cells, and discloses a kind of antimony selenide sputtering target material and its preparation method.The preparation method comprises the following steps: after mixing selenium particles and antimony particles, put them into a tube furnace, heat to 215-230 DEG C under protective atmosphere for calcination treatment, then heat to 650-680 DEG C for high temperature sintering, the material is cooled with the furnace, and an antimony selenide ingot is obtained; then crush the antimony selenide ingot and pass it through a 325-360 mesh stainless steel screen to obtain antimony selenide alloy powder with a particle size of less than 45 microns; the antimony selenide alloy powder is pre-pressed to obtain an antimony selenide blank, heated to 505-510 DEG C under vacuum and pressurized to 35-38T for hot isostatic pressing forming to obtain the antimony selenide sputtering target material. The application uses selenium particles and antimony particles as raw materials, and through high temperature sintering, crushing, screening and hot isostatic pressing forming processes, the obtained antimony selenide sputtering target material has the advantages of high density, high purity, uniform composition, etc.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sputtering materials for solar cell thin films, and particularly relates to a kind of antimony selenide sputtering target material and a preparation method thereof. BACKGROUND

[0002] With the continuous expansion of energy demand and the increasingly prominent environmental problems, the research and utilization of renewable energy are increasingly valued by researchers. Among them, solar energy as a clean renewable energy is developing very rapidly, and thin-film solar cells have attracted great attention from researchers and become the most popular research topic at present. Traditional thin-film solar cells include copper indium gallium selenide (CIGS) thin-film cells and cadmium telluride (CdTe) thin-film cells. The former has a complex production process and high cost of raw materials In and Ga. The latter needs to be improved in environmental safety, and the reserves of Te in the earth's crust are also very limited. Therefore, it is necessary to prepare a safe, efficient and low-cost solar cell thin film material.

[0003] Patent CN 108468027 A discloses a preparation method of an antimony-doped copper-zinc-tin-sulfur-selenium target. First, copper-zinc-tin-sulfur-selenium powder and Sb-containing powder are ball-milled and mixed to obtain a raw material mixture; then the raw material mixture is sintered to obtain an antimony-doped copper-zinc-tin-sulfur-selenium target. However, the copper-zinc-tin-sulfur-selenium thin-film solar cell technology is not mature at present, and its photoelectric conversion efficiency needs to be further improved. CN 110128143 A discloses a preparation method of a cadmium selenide target. The cadmium selenide target can be prepared by directly hot-pressing and sintering the mixed selenium powder and cadmium powder. However, it still has the environmental safety problem of Cd.

[0004] Antimony selenide, with the chemical formula Sb2Se3, is a binary single-phase compound. It has a large raw material reserve, low toxicity and low price. Moreover, it has a suitable energy band width (~1.15eV), a large optical absorption coefficient (>105cm-1), and a low crystal growth temperature. Therefore, its target material is very suitable for use in the preparation of a new type of sputtering material for solar cell thin films. However, there are few reports on the preparation method of antimony selenide target. -1 SUMMARY

[0005] In view of the shortcomings and deficiencies of the prior art, the primary purpose of the present application is to provide a preparation method of high-quality antimony selenide sputtering target.

[0006] Another purpose of the present application is to provide an antimony selenide sputtering target prepared by the above method.

[0007] The purpose of the present application is achieved by the following technical solutions:

[0008] A preparation method of an antimony selenide sputtering target, comprising the following preparation steps:

[0009] ​(1) high-temperature sintering: the selenium particles and the antimony particles are mixed and then put into a tube furnace, calcination treatment is performed under a protective atmosphere at a temperature of 215-230°C, and then high-temperature sintering is performed at a temperature of 650-680°C, the material is cooled with the furnace, and an antimony selenide ingot is obtained;

[0010] (2) crushing and sieving: the obtained antimony selenide ingot is crushed and then sieved through a 325-360 mesh stainless steel screen, and an antimony selenide alloy powder with a particle size of <45 μm is obtained;

[0011] (3) hot isostatic pressing: the obtained antimony selenide alloy powder is pre-pressed to obtain an antimony selenide blank, and then hot isostatic pressing is performed under vacuum at a temperature of 505-510°C and a pressure of 35-38T, and an antimony selenide sputtering target is obtained.

[0012] Further, the mass ratio of the antimony particles to the selenium particles mixed in step (1) is 1:1.03-1.06.

[0013] Further, the protective atmosphere in step (1) is high-purity argon, and the flow rate of the protective atmosphere is 1-10 L / min, preferably 1-3 L / min.

[0014] Further, the rate of temperature increase in step (1) is 3-6°C / min.

[0015] Further, the calcination treatment in step (1) is performed for 60-180 min, and the high-temperature sintering is performed for 240-360 min.

[0016] Further, the crushing in step (2) is performed in a glove box with a water content of <15 ppm and an oxygen content of <20 ppm, and preferably a water content of <10 ppm and an oxygen content of <10 ppm.

[0017] Further, the crushing process in step (2) is as follows: first, the surface debris of the antimony selenide ingot is cleaned with high-pressure gas, then the antimony selenide ingot is crushed into small pieces of 2-5 mm with a tungsten carbide hammer, and then the small pieces are further crushed with a powdering machine.

[0018] Further, the graphite mold with graphite paper is used for pre-pressing and hot isostatic pressing in step (3).

[0019] Further, the pressure for pre-pressing in step (3) is 8-12 MPa.

[0020] Further, the vacuum condition in step (3) refers to a vacuum degree of 5-10 Pa, the rate of temperature increase is 5-15°C / min, the temperature is increased to 505-510°C, and then the temperature is maintained for 30-60 min before the pressure is increased, the pressure is increased to 35-38T uniformly within 25-40 min, and the hot isostatic pressing is performed for 60-90 min.

[0021] The selenide antimony sputtering target is prepared by the method.

[0022] Compared with the prior art, the selenide antimony sputtering target has the advantages of large reserves of raw materials, low price, and industrial production.

[0023] (1) The selenide antimony sputtering target is prepared by using selenium particles and antimony particles as raw materials, has the advantages of large reserves of raw materials, low price, and industrial production.

[0024] (2) The selenide antimony sputtering target prepared by the method has the advantages of high density, high purity, and uniform composition.

[0025] (3) The selenide antimony alloy powder prepared by the method has low oxygen content and stable phase, and is a high-quality sputtering target raw material. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a metallographic structure diagram of the selenide antimony sputtering target obtained in Example 1.

[0027] Figure 2 It is a DSC diagram of the selenide antimony sputtering target obtained in Example 1.

[0028] Figure 3 It is an XRD diagram of the selenide antimony sputtering target obtained in Example 1.

[0029] Figure 4 It is a curve diagram of the saturation vapor pressure of selenium changing with temperature. DETAILED DESCRIPTION

[0030] The application will be described in further detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the application are not limited thereto.

[0031] Example 1

[0032] (1) High-temperature sintering: The 5N purity antimony particles and selenium particles are loaded into a covered crucible in a mass ratio of Sb:Se=1:1.04 and placed in the heating zone of a tube furnace, high-purity argon gas is introduced at a flow rate of 2L / min to remove the air in the tube, the temperature is raised to 215℃ at a rate of 3℃ / min, and then the temperature is raised to 650℃ after 60min of heat preservation. The program ends, and the material is cooled with the furnace.

[0033] (2) Crushing and screening: The glove box is purified to have a water and oxygen content of less than 10ppm, the selenide antimony ingot is taken out and cleaned with high-pressure gas, and then placed in the glove box. The ingot is crushed into small pieces less than 5mm with a tungsten carbide hammer. Then the powder is further crushed with a powder machine and screened with a 325 mesh screen to obtain selenide antimony alloy powder less than 45μm.

[0034] (3) Hot isostatic pressing: the sieved antimony selenide alloy powder is evenly placed in a graphite mold with graphite paper placed in it, and then the mold is placed stably in a vacuum hot pressing furnace, with the mold placed in the center of the pressing shaft. First, pre-pressing is performed at a pressure of 8 MPa, and after 3 min, the pressure is released to obtain an antimony selenide blank. The furnace door is closed, the vacuum pump is started, the vacuum degree is brought to 5 Pa, the temperature is raised to 510°C at a rate of 10°C / min, and after 30 min of heat preservation, the pressure is started to be increased. The pressure is uniformly increased to 35T in 25 min, and after 60 min of heat preservation and pressure retention, the pressure is slowly reduced, and the target material is cooled with the furnace. The antimony selenide alloy blank is obtained after furnace discharge and demolding. After machining, the semiconductor antimony selenide sputtering target material is obtained after detection.

[0035] The metallographic structure diagram, DSC diagram and XRD diagram of the antimony selenide sputtering target material obtained in this example are shown in Figure 1 , Figure 2 and Figure 3 respectively.

[0036] Example 2

[0037] (1) High-temperature sintering: 5N purity antimony particles and selenium particles are loaded into a covered crucible in a mass ratio of Sb:Se = 1:1.06 and placed in the heating zone of a tube furnace, and high-purity argon gas is introduced at a flow rate of 3L / min to completely remove the air in the tube. The temperature is raised to 220°C at a rate of 4°C / min, and after 75 min of heat preservation, the temperature is raised to 645°C, and after 270 min of heat preservation, the program is ended, and the material is cooled with the furnace.

[0038] (2) Crushing and sieving: the glove box is purified to make the water and oxygen content reach the standard of within 8 ppm, and the antimony selenide ingot is taken out and cleaned with high-pressure gas and placed in the glove box. The ingot is broken into small pieces less than 4 mm with a tungsten carbide hammer. Then the powder machine is used for further crushing, and the powder is sieved with a 325 mesh sieve to obtain antimony selenide alloy powder less than 45 μm.

[0039] (3) Hot isostatic pressing: the sieved antimony selenide alloy powder is evenly placed in a graphite mold with graphite paper placed in it, and then the mold is placed stably in a vacuum hot pressing furnace, with the mold placed in the center of the pressing shaft. First, pre-pressing is performed at a pressure of 8 MPa, and after 3 min, the pressure is released to obtain an antimony selenide blank. The furnace door is closed, the vacuum pump is started, the vacuum degree is brought to 5 Pa, the temperature is raised to 510°C at a rate of 10°C / min, and after 30 min of heat preservation, the pressure is started to be increased. The pressure is uniformly increased to 35T in 25 min, and after 60 min of heat preservation and pressure retention, the pressure is slowly reduced, and the target material is cooled with the furnace. The antimony selenide alloy blank is obtained after furnace discharge and demolding. After machining, the semiconductor antimony selenide sputtering target material is obtained after detection.

[0040] Example 3

[0041] (1) High temperature sintering: Put the 5N purity selenium particles and antimony particles into a crucible with a cover in a ratio of Sb:Se = 1:1.05 by mass and put them into the heating zone of a tube furnace. Purge the tube with high-purity argon at a flow rate of 3 L / min to remove the air in the tube. Increase the temperature to 225°C at a rate of 5°C / min, and then increase the temperature to 640°C after holding for 80 min. After the process is completed, cool the material with the furnace.

[0042] (2) Crushing and screening: Purify the glove box to make the water and oxygen content in the glove box reach the standard of less than 5 ppm. Take out the antimony selenide ingot and clean the surface with high-pressure gas, and then put it into the glove box. Crush it into small pieces less than 3 mm with a tungsten carbide hammer. Then continue to crush it with a powder machine, and screen the powder with a 325 mesh screen to obtain antimony selenide alloy powder less than 45 μm.

[0043] (3) Hot isostatic pressing: Place the screened antimony selenide alloy powder evenly in a graphite mold with graphite paper placed in it, and then place the mold stably in the vacuum hot pressing furnace, with the mold centered on the pressing shaft. First, pre-press at a pressure of 12 MPa, and then release the pressure after 5 min to obtain an antimony selenide blank. Close the furnace door, start the vacuum pump, and increase the temperature to 505°C at a rate of 10°C / min. After holding for 50 min, start to press. Increase the pressure uniformly to 38T in 25 min, and then hold the pressure for 90 min. Slowly reduce the pressure, and cool the target material with the furnace. Take out the antimony selenide alloy blank after demolding. After machining, the semiconductor antimony selenide sputtering target material is obtained after detection.

[0044] Comparative Example 1

[0045] This comparative example is compared with Example 1. The second stage of high temperature sintering in step (1) is shortened to 60 min, and the rest is the same. The specific preparation steps are as follows:

[0046] (1) High temperature sintering: Put the 5N purity selenium particles and antimony particles into a crucible with a cover in a ratio of Sb:Se = 1:1.05 by mass and put them into the heating zone of a tube furnace. Purge the tube with high-purity argon at a flow rate of 3 L / min to remove the air in the tube. Increase the temperature to 225°C at a rate of 5°C / min, and then increase the temperature to 640°C after holding for 80 min. After the process is completed, cool the material with the furnace.

[0047] Steps (2) crushing and screening and (3) hot isostatic pressing are the same as in Example 1.

[0048] Comparative Example 2

[0049] This comparative example is compared with Example 3. Step (2) crushing and screening is not performed in a vacuum glove box, and the rest is the same. The specific preparation steps are as follows:

[0050] Step (1) high temperature sintering is the same as in Example 3.

[0051] (2) Breaking and sieving: The ingot of antimony selenide was taken out and cleaned with high pressure gas. The ingot was broken into small pieces less than 3 mm with a tungsten carbide hammer. Then the powder was further broken with a powder mill and sieved with a 325 mesh screen to obtain the antimony selenide alloy powder less than 45 μm.

[0052] Step (3) hot isostatic pressing was the same as Example 3.

[0053] Comparative Example 3

[0054] This comparative example was the same as Example 3 except that the pressure in step (3) hot isostatic pressing was reduced to 25T. The specific preparation steps were as follows:

[0055] Step (1) high temperature sintering and step (2) breaking and sieving were the same as Example 3.

[0056] (3) Hot isostatic pressing: The sieved antimony selenide alloy powder was placed evenly in a graphite mold with graphite paper placed in it, and then the mold was placed steadily in a vacuum hot pressing furnace so that the mold was at the center of the pressing shaft. First, pre-pressing was performed at 12 MPa, and then the pressure was released after 5 min to obtain an antimony selenide blank. The furnace door was closed, the vacuum pump was started, the vacuum degree was brought to 7 Pa, the temperature was raised to 505°C at a rate of 10°C / min, and then the pressure was increased after 50 min of heat preservation. The pressure was increased to 25T uniformly in 25 min, and then the pressure was maintained for 90 min after heat preservation. The pressure was slowly released, and the target material was cooled with the furnace. The antimony selenide alloy blank was obtained after the furnace was discharged and demolded. After machining, a semiconductor antimony selenide sputtering target was obtained.

[0057] Comparative Example 4

[0058] This comparative example was the same as Example 3 except that the temperature in step (3) hot isostatic pressing was reduced to 400°C. The specific preparation steps were as follows:

[0059] Step (1) high temperature sintering and step (2) breaking and sieving were the same as Example 3.

[0060] (3) Hot isostatic pressing: The sieved antimony selenide alloy powder was placed evenly in a graphite mold with graphite paper placed in it, and then the mold was placed steadily in a vacuum hot pressing furnace so that the mold was at the center of the pressing shaft. First, pre-pressing was performed at 12 MPa, and then the pressure was released after 5 min to obtain an antimony selenide blank. The furnace door was closed, the vacuum pump was started, the vacuum degree was brought to 7 Pa, the temperature was raised to 400°C at a rate of 10°C / min, and then the pressure was increased after 50 min of heat preservation. The pressure was increased to 38T uniformly in 25 min, and then the pressure was maintained for 90 min after heat preservation. The pressure was slowly released, and the target material was cooled with the furnace. The antimony selenide alloy blank was obtained after the furnace was discharged and demolded. After machining, a semiconductor antimony selenide sputtering target was obtained.

[0061] Comparative Example 5

[0062] Compared with Example 1, this comparative example does not perform the first stage calcination treatment in advance in step (1), and the rest is the same. The specific steps are as follows:

[0063] (1) High-temperature sintering: 5N purity antimony particles and selenium particles are loaded into a covered crucible at a mass ratio of Sb:Se = 1:1.04 and placed in the heating zone of a tubular furnace. High-purity argon gas is introduced at a flow rate of 2 L / min to expel the air in the tube. The temperature is raised to 650°C at a rate of 3°C / min and kept at this temperature for 240 min. The program is terminated and the materials are cooled with the furnace.

[0064] Step (2) crushing and screening and step (3) hot isostatic pressing are the same as in Example 1.

[0065] The test results of the relative density, oxygen content and Sb component mass percentage of the antimony selenide sputtering targets obtained in the above examples and comparative examples are shown in Table 1 below.

[0066] Table 1

[0067] [CAT] Sb2Se3 target Relative density Oxygen content / ppm Component Sb / wt% Example 1 99.35％ 376 50.65 Example 2 99.21％ 345 50.64 Example 3 99.18％ 299 50.58 Comparative Example 1 99.36％ 296 42.71 Comparative Example 2 99.10％ 1175 50.66 Comparative Example 3 94.73％ 321 50.49 Comparative Example 4 93.68％ 338 50.51 Comparative Example 5 99.27％ 394 75.24

[0068] It can be seen from the results in Table 1 that the antimony selenide sputtering target products obtained in each embodiment of the present invention have a high relative density (more than 99%), high purity, and low oxygen content (below 400ppm). In comparison: In the preparation method of the product of Comparative Example 1, the second stage sintering and heat preservation time is insufficient, resulting in incomplete synthesis reaction and large segregation of the prepared target product. In the preparation method of the product of Comparative Example 2, since the antimony selenide ingot was not broken in the vacuum glove box, the oxygen content of the target was nearly 4 times higher than that of the embodiment. In the preparation method of the product of Comparative Example 3, the pressure of the target was too low, and the relative density of the final product was lower than 95%, which was inconsistent with the expected standard. In the preparation method of the product of Comparative Example 4, the temperature of the target was too low, and the relative density of the final product was less than 94%, which did not meet the requirements. In the preparation method of the product of Comparative Example 5, the first stage calcination treatment was not carried out in advance, resulting in a large amount of volatilization of Se and serious segregation of the prepared target product. The curve of the change of saturated vapor pressure of selenium with temperature is shown in Figure 2. Figure 4 As shown. Figure 4 It has been found that the saturated vapor pressure of selenium increases rapidly with increasing temperature. To avoid large-scale volatilization of Se during sintering, the present invention adopts a staged synthesis method. The first stage is calcination, which is then kept warm to allow the selenium particles to initially react and solidify. The second stage is sintering at elevated temperatures to completely complete the reaction of the antimony selenide alloy and remove free selenium and free antimony selenide.

[0069] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing an antimony selenide sputtering target, characterized in that: The method comprises the following preparation steps: (1) High-temperature sintering: Selenium particles and antimony particles are mixed and placed in a tube furnace. The temperature is raised to 215-230°C under a protective atmosphere for calcination. The temperature is then raised to 650-680°C for high-temperature sintering. The material is cooled in the furnace to obtain antimony selenide ingots. (2) Crushing and screening: The obtained antimony selenide ingot is crushed and passed through a 325-360 mesh stainless steel sieve to obtain antimony selenide alloy powder with a particle size of less than 45 μm; (3) Hot isostatic pressing: The obtained antimony selenide alloy powder is pre-pressed to obtain an antimony selenide blank, which is then heated to 505-510°C and pressurized to 35-38°F under vacuum conditions for hot isostatic pressing to obtain an antimony selenide sputtering target. The mass ratio of the antimony particles to the selenium particles in step (1) is 1:1.03-1.06, the heating rate is 3-6°C / min, the calcination time is 60-180 min, and the high-temperature sintering time is 240-360 min. The crushing in step (2) is carried out in a glove box with a water content of less than 10 ppm and an oxygen content of less than 10 ppm.

2. The method for preparing an antimony selenide sputtering target according to claim 1, wherein: The protective atmosphere in step (1) is high-purity argon; the protective atmosphere flow rate is 1~10L / min.

3. The method for preparing an antimony selenide sputtering target according to claim 1, wherein: The crushing process in step (2) is to first clean the debris on the surface of the antimony selenide ingot with high-pressure gas, then use a tungsten carbide hammer to crush the antimony selenide ingot into small pieces of 2-5 mm, and then use a powder grinder to further crush the small pieces.

4. The method for preparing an antimony selenide sputtering target according to claim 1, wherein: The pre-pressing and hot isostatic pressing in step (3) use a graphite mold with graphite paper placed on it; the pre-pressing pressure is 8~12MPa.

5. The method for preparing an antimony selenide sputtering target according to claim 1, wherein: The vacuum condition in step (3) refers to a vacuum degree of 5-10 Pa, the heating rate is 10°C / min, the heating to 505-510°C is maintained for 30 minutes and then pressurization is started, the pressurization to 35-38°C refers to uniform pressurization to 35-38°C in 25 minutes, and the hot isostatic pressing time is 60 minutes.

6. An antimony selenide sputtering target, characterized in that: It is prepared by the method according to any one of claims 1 to 5.

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