1. A preparation method of a zinc telluride doped planar target is characterized by comprising the following steps:

s1) mixing: mixing zinc telluride powder, zinc simple substance powder and tellurium simple substance powder to obtain a mixed material;

s2) sintering: heating and sintering the mixed material to obtain a sintered material;

s3) ball milling: performing ball milling on the sintering material to obtain a ball-milled material;

s4) prepressing: prepressing the ball-milled material to obtain a molded blank body;

s5) hot pressing: and carrying out vacuum hot-pressing sintering on the molded blank to obtain the zinc telluride doped planar target.

2. The preparation method of claim 1, wherein the purity of the zinc telluride powder is greater than or equal to 4.5N; the purity of the zinc simple substance powder is more than or equal to 2N; the purity of the tellurium elementary substance powder is more than or equal to 4.5N; the mass ratio of the zinc telluride powder to the elemental zinc powder to the elemental tellurium powder is 8:1: 1-10: 1: 1.

3. The method according to claim 1, wherein a grinding ball is added during the mixing in step S1); the ratio of the total amount of the zinc telluride powder, the zinc elemental powder and the tellurium elemental powder to the number of the grinding balls is (20-40) kg: (4-8); the diameter of the grinding ball is 20-40 cm; the mixing speed is 40-60 r/min; the mixing time is 4-8 h; the mixing is carried out in a protective atmosphere.

4. The preparation method according to claim 1, wherein the step S2) is specifically:

heating the mixed material to 100-140 ℃, and preserving heat for 20-40 min; and then continuously heating to 400-500 ℃, and preserving the heat for 20-40 min to obtain a sintering material.

5. The preparation method of claim 1, wherein the ball-milling in the step S3) has a ball-to-material ratio of (1-2): 1; the grinding balls used for ball milling comprise large balls, medium balls and small balls; the number ratio of the large balls, the medium balls and the small balls is 1: (0.8-1.2): (0.6-1.4); the rotating speed of the ball milling is 50-70 r/min; the ball milling time is 2-4 h; the ball milling is carried out in a protective atmosphere.

6. The method according to claim 1, wherein the ball milling material is pre-pressed in a graphite mold in the step S4); the pre-pressing pressure is 20-30T; and the prepressing time is 30-90 min.

7. The preparation method according to claim 1, wherein the step S5) is specifically:

heating to 300-450 ℃ under the vacuum condition, and carrying out first-stage heat preservation;

after the first-stage heat preservation is finished, continuously heating to 550-650 ℃, and carrying out second-stage heat preservation;

and pressurizing after the second stage of heat preservation is finished, and preserving heat and maintaining pressure after the pressure reaches 40-45 MPa to obtain the zinc telluride doped target material.

8. The preparation method according to claim 7, wherein after the heat preservation and pressure preservation are finished, the mixture is cooled to be lower than 450 ℃, then protective atmosphere is introduced, and the temperature is reduced to room temperature, so that the zinc telluride doped target material is obtained.

9. The method according to claim 7, wherein the heating rate is 4 to 7 ℃/min; the first-stage heat preservation time is 30-60 min; the rate of continuously heating is 9-10 ℃/min; the second stage heat preservation time is 60-100 min; the time for heat preservation and pressure maintaining is 2-3 h.

10. The zinc telluride doped planar target prepared by the preparation method of any one of claims 1 to 9.

Background

ZnTe is a II-VI compound, a p-type wide bandgap semiconductor, and has a bandgap of 2.26eV at room temperature and a bandgap of 2.38eV at 77K.

The zinc telluride (ZnTe) film is an important semiconductor photoelectric material and has important application in the fields of photoluminescence and electroluminescent devices, solar cells, infrared detectors, thermal imaging technology and the like.

At present, the preparation technology of the zinc telluride film mainly comprises electron beam vapor deposition, magnetron sputtering and the like, and the preparation methods all use the zinc telluride target as a raw material, so that the preparation of the high-purity and high-density zinc telluride target is very important for the application of the material.

Disclosure of Invention

In view of this, the present invention provides a zinc-doped zinc telluride planar target with high photoelectric conversion efficiency and a preparation method thereof.

The invention provides a preparation method of a zinc telluride doped planar target, which comprises the following steps:

s1) mixing: mixing zinc telluride powder, zinc simple substance powder and tellurium simple substance powder to obtain a mixed material;

s2) sintering: heating and sintering the mixed material to obtain a sintered material;

s3) ball milling: performing ball milling on the sintering material to obtain a ball-milled material;

s4) prepressing: prepressing the ball-milled material to obtain a molded blank body;

s5) hot pressing: and carrying out vacuum hot-pressing sintering on the molded blank to obtain the zinc telluride doped planar target.

Preferably, the purity of the zinc telluride powder is more than or equal to 4.5N; the purity of the zinc simple substance powder is more than or equal to 2N; the purity of the tellurium elementary substance powder is more than or equal to 4.5N; the mass ratio of the zinc telluride powder to the elemental zinc powder to the elemental tellurium powder is 8:1: 1-10: 1: 1.

Preferably, grinding balls are added during the mixing in the step S1); the ratio of the total amount of the zinc telluride powder, the zinc elemental powder and the tellurium elemental powder to the number of the grinding balls is (20-40) kg: (4-8); the diameter of the grinding ball is 20-40 cm; the mixing speed is 40-60 r/min; the mixing time is 4-8 h; the mixing is carried out in a protective atmosphere.

Preferably, the step S2) is specifically:

heating the mixed material to 100-140 ℃, and preserving heat for 20-40 min; and then continuously heating to 400-500 ℃, and preserving the heat for 20-40 min to obtain a sintering material.

Preferably, the ball-to-material ratio of the ball milling in the step S3) is (1-2): 1; the grinding balls used for ball milling comprise large balls, medium balls and small balls; the number ratio of the large balls, the medium balls and the small balls is 1: (0.8-1.2): (0.6-1.4); the rotating speed of the ball milling is 50-70 r/min; the ball milling time is 2-4 h; the ball milling is carried out in a protective atmosphere.

Preferably, the ball milling material in the step S4) is pre-pressed in a graphite mold; the pre-pressing pressure is 20-30T; and the prepressing time is 30-90 min.

Preferably, the step S5) is specifically:

heating to 300-450 ℃ under the vacuum condition, and carrying out first-stage heat preservation;

after the first-stage heat preservation is finished, continuously heating to 550-650 ℃, and carrying out second-stage heat preservation;

and pressurizing after the second stage of heat preservation is finished, and preserving heat and maintaining pressure after the pressure reaches 40-45 MPa to obtain the zinc telluride doped target material.

Preferably, after the heat preservation and pressure preservation are finished, cooling to be lower than 450 ℃, introducing a protective atmosphere, and cooling to room temperature to obtain the zinc telluride doped target.

Preferably, the heating rate is 4-7 ℃/min; the first-stage heat preservation time is 30-60 min; the rate of continuously heating is 9-10 ℃/min; the second stage heat preservation time is 60-100 min; the time for heat preservation and pressure maintaining is 2-3 h.

The invention also provides the zinc telluride doped planar target prepared by the preparation method.

The invention provides a preparation method of a zinc telluride doped planar target, which comprises the following steps: s1) mixing: mixing zinc telluride powder, zinc simple substance powder and tellurium simple substance powder to obtain a mixed material; s2) sintering: heating and sintering the mixed material to obtain a sintered material; s3) ball milling: performing ball milling on the sintering material to obtain a ball-milled material; s4) prepressing: prepressing the ball-milled material to obtain a molded blank body; s5) hot pressing: and carrying out vacuum hot-pressing sintering on the molded blank to obtain the zinc telluride doped planar target. Compared with the prior art, the zinc and tellurium are doped in the zinc telluride, so that the conductivity of the original zinc telluride target can be improved, the purity and the density of the prepared target are higher, the sputtering conductivity of the target can be improved, and the preparation method has the advantages of simple process, lower requirement on equipment, lower cost and batch production.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a preparation method of a zinc telluride doped planar target, which comprises the following steps: s1) mixing: mixing zinc telluride powder, zinc simple substance powder and tellurium simple substance powder to obtain a mixed material; s2) sintering: heating and sintering the mixed material to obtain a sintered material; s3) ball milling: performing ball milling on the sintering material to obtain a ball-milled material; s4) prepressing: prepressing the ball-milled material to obtain a molded blank body; s5) hot pressing: and carrying out vacuum hot-pressing sintering on the molded blank to obtain the zinc telluride doped planar target.

In the present invention, the sources of all raw materials are not particularly limited, and they may be commercially available.

Firstly, mixing materials: mixing zinc telluride powder, zinc simple substance powder and tellurium simple substance powder to obtain a mixed material; the purity of the zinc telluride powder is preferably more than or equal to 4.5N; the purity of the zinc simple substance powder is preferably more than or equal to 2N; the purity of the tellurium elementary substance powder is preferably more than or equal to 4.5N, and more preferably more than or equal to 5N; because zinc telluride and zinc form a solid solution, and zinc is completely wrapped in the crystal by the zinc telluride, a part of tellurium simple substance powder needs to be doped, and a zinc-doped target material of the zinc telluride can be obtained without introducing other impurities, so that the conductivity of the zinc-doped target material is improved; the mass ratio of the zinc telluride powder to the elemental zinc powder to the elemental tellurium powder is 8:1: 1-10: 1: 1; the mixing is preferably carried out in a protective atmosphere; the protective atmosphere is not particularly limited as long as it is known to those skilled in the art, and nitrogen is preferred in the present invention; the mixing is preferably carried out in a homogenizer, more preferably in a tumbling homogenizer; grinding balls are preferably added during mixing; the preferred ratio of the total amount of the zinc telluride powder, the zinc elemental powder and the tellurium elemental powder to the number of the grinding balls is (20-40) kg: (4-8); the diameter of the grinding ball is preferably 20-40 cm, and more preferably 30 cm; the mixing rotating speed is preferably 40-60 r/min; the mixing time is preferably 4-8 h.

Then sintering the mixed material; the sintering is preferably as follows: heating the mixed material to 100-140 ℃, preferably to 110-130 ℃, more preferably to 120 ℃, and preserving heat for 20-40 min, preferably for 25-35 min, more preferably for 30 min; then, continuously heating to 400-500 ℃, and preserving heat for 20-40 min, preferably for 25-35 min, more preferably for 30min to obtain a sintered material; the heating rate is preferably 5-7 ℃/min; the rate of continuous temperature rise is preferably 5-6 ℃/min.

Performing ball milling on the sintering material to obtain a ball-milled material; the ball milling is preferably carried out in a protective atmosphere; the protective atmosphere is not particularly limited as long as it is known to those skilled in the art, and nitrogen is preferred in the present invention; the ball-material ratio of the ball milling is preferably (1-2): 1, more preferably (1 to 1.5): 1, more preferably 1: 1; the grinding balls used for ball milling preferably comprise large balls, medium balls and small balls; the number ratio of the large balls, the medium balls and the small balls is preferably 1: (0.8-1.2): (0.6 to 1.4), more preferably 1:1: 1; the diameter of the large ball is preferably 20-30 cm; the diameter of the middle ball is preferably 15 cm; the diameter of the pellet is preferably 10 cm; the rotation speed of the ball milling is preferably 50-70 r/min; the ball milling time is preferably 2-4 h.

Prepressing the ball-milled material to obtain a molded blank body; the pre-pressing is preferably carried out in a graphite mold, and the graphite mold is resistant to high temperature and high pressure; the graphite die and the ball-milling material are preferably separated by graphite paper so as to be easy to demould and the graphite paper is easy to remove; the pre-pressing pressure is preferably 20-30T, and more preferably 25T; the pre-pressing time is preferably 30-90 min, and more preferably 30-60 min.

Carrying out vacuum hot-pressing sintering on the molded blank; the oxygen content can be controlled under vacuum condition and the introduction of impurities can be reduced; in the invention, the pre-pressed molded blank is directly subjected to vacuum hot-pressing sintering without being taken out of a graphite mold; the vacuum degree of the vacuum hot-pressing sintering is preferably less than or equal to 10 Pa; because the melting points of zinc and tellurium are both lower and sensitive to temperature, if the temperature is higher, the volatilization amounts of zinc and tellurium are larger, so that the volatilization of free matters is caused, the electrical conductivity of the target material is poor, if the sintering temperature is lower, the optimal molecular activity of sintering cannot be achieved, although the content of tellurium is more, the density cannot be achieved, and the electrical conductivity of the target material is also poor; therefore, in the present invention, the vacuum hot-pressing sintering is specifically: heating to 300-450 ℃ under the vacuum condition, and carrying out first-stage heat preservation; after the first-stage heat preservation is finished, continuously raising the temperature to 550-650 ℃, preferably continuously raising the temperature to 550-620 ℃, more preferably continuously raising the temperature to 600-620 ℃, and carrying out second-stage heat preservation; pressurizing after the second stage of heat preservation is finished, and preserving heat and pressure after the pressure reaches 40-45 MPa; the heating rate is preferably 4-7 ℃/min; the first-stage heat preservation time is preferably 30-60 min; the rate of continuous temperature rise is preferably 9-10 ℃/min; the second-stage heat preservation time is preferably 60-100 min; the output power of the pressure during pressurization is preferably 0.5-1W; the time for heat preservation and pressure maintaining is preferably 2-3 h; after the heat preservation and pressure preservation are finished, preferably cooling to be lower than 450 ℃, introducing protective atmosphere, and cooling to room temperature; the protective atmosphere is not particularly limited as long as it is known to those skilled in the art, and nitrogen is preferred in the present invention; cooling to room temperature, preferably performing demolding treatment, and performing Computer Numerical Control (CNC) machining to obtain the zinc telluride doped zinc planar target; the CNC processing is finished into a sheet, and the purpose of removing impurities can be achieved.

The zinc and tellurium are doped in the zinc telluride, so that the conductivity of the original zinc telluride target can be improved, the purity and the density of the prepared target are higher, the sputtering conductivity of the target can be improved, and the preparation method has the advantages of simple process, lower requirement on equipment, lower cost and batch production.

The invention also provides the zinc telluride doped planar target prepared by the preparation method.

In order to further illustrate the present invention, the following describes in detail a zinc telluride doped planar target and a preparation method thereof in combination with embodiments.

The reagents used in the following examples are all commercially available.

Example 1

1.1, preparing materials: the mass ratio of ZnTe to Zn Te is 8:1:1(ZnTe purity is 4.5N, Zn purity, 2N, Te purity is 5N).

1.2 mixing materials: introducing nitrogen, charging 20kg of the prepared zinc-doped zinc telluride powder in a 20L PE barrel, adding 4 zirconium balls (diameter of 30CM), and homogenizing for 6h on a rolling homogenizer. The rotating speed of the homogenizer is 60 r/min.

1.3, sintering: first-stage temperature rise: heating from room temperature to 120 deg.C, heating at a heating rate of 5 deg.C/min, heating to 120 deg.C, and holding for 30 min. And (3) heating in the second stage: heating from 120 ℃ to 400 ℃, wherein the heating rate is 5 ℃/min, and keeping the temperature at 400 ℃ for 30 min.

1.4 ball milling: nitrogen was passed through and the zirconium spheres were sized as large (20 cm diameter): medium (15 cm diameter): small (diameter 10cm) ═ 1:1:1, zircon sphere: 1:1, ball-milling and crushing on a ball mill at the rotating speed of 70r/min for 2 h.

1.5 charging: the above ball-milled material was charged into a graphite mold, wherein the size of the charging mold was 208mm × 116mm and the charge was 2 kg.

1.6 pre-pressing the powder for 30min at 25T after feeding the powder into the furnace, opening a rough pumping valve, a mechanical pump and a roots pump in sequence after pre-pressing to vacuumize the furnace body, and starting heating when the vacuum degree of the furnace body is less than 10 Pa.

1.7 first-stage heating: heating from room temperature to 450 deg.C, heating at a heating rate of 5 deg.C/min to 450 deg.C, and maintaining for 60 min.

1.8 second-stage heating: after the first stage is finished, heating to 600 ℃ at the heating rate of 10 ℃/min and preserving the heat for 100 min.

1.9 after the heat preservation, the pressurization is started, the pressurization pressure is 45MPa, the output power of the pressure is 0.5W, and the pressure is maintained for 2h after the pressurization is finished.

1.10 after the pressure is maintained, the temperature begins to naturally decrease, and after the temperature is lower than 450 ℃, the rough pumping valve, the roots pump and the mechanical pump are closed in sequence, and finally N is introduced₂And cooling to room temperature.

1.11, cooling to room temperature, discharging, demolding to obtain a blank target material of zinc telluride doped with zinc, and performing CNC (computer numerical control) processing to obtain the qualified target material of zinc telluride doped with zinc.

The theoretical density of the target material is 5.73g/cm³The actual density is 5.37g/cm³. The relative density was 93.71%.

Example 2

2.1, preparing materials: the mass ratio of ZnTe to Zn Te is 8:1:1(ZnTe purity is 4.5N, Zn purity, 2N, Te purity is 5N).

2.2 mixing materials: introducing nitrogen, charging 20kg of the prepared zinc-doped zinc telluride powder in a 20L PE barrel, adding 4 zirconium balls (diameter of 30CM), and homogenizing for 6h on a rolling homogenizer. The rotating speed of the homogenizer is 60 r/min.

2.3, sintering: first-stage temperature rise: heating from room temperature to 120 deg.C, heating at a heating rate of 5 deg.C/min, heating to 120 deg.C, and holding for 30 min. And (3) heating in the second stage: heating from 120 ℃ to 400 ℃, wherein the heating rate is 5 ℃/min, and keeping the temperature at 400 ℃ for 30 min.

2.4 ball milling: nitrogen was passed through and the zirconium spheres were sized as large (20 cm diameter): medium (15 cm diameter): small (diameter 10cm) ═ 1:1:1, zircon sphere: 1:1, ball-milling and crushing on a ball mill at the rotating speed of 70r/min for 2 h.

2.5 charging: the above ball-milled material was charged into a graphite mold, wherein the size of the charging mold was 208mm × 116mm and the charge was 2 kg.

2.6 pre-pressing the powder for 30min at 25T after feeding the powder into the furnace, opening a rough pumping valve, a mechanical pump and a roots pump in sequence after pre-pressing is finished to vacuumize the furnace body, and starting heating when the vacuum degree of the furnace body is less than 10 Pa.

2.7 first-stage heating: heating from room temperature to 450 deg.C, heating at a heating rate of 5 deg.C/min to 450 deg.C, and maintaining for 60 min.

2.8 second-stage heating: after the first stage of heat preservation, the mixture is heated to 550 ℃ at the heating rate of 10 ℃/min and is preserved for 100 min.

2.9 after the heat preservation, the pressurization is started, the pressurization pressure is 45MPa, the output power of the pressure is 0.5W, and the pressure is maintained for 2h after the pressurization is finished.

2.10 after the pressure is maintained, the temperature is naturally reduced, after the temperature is lower than 450 ℃, the rough pumping valve, the roots pump and the mechanical pump are closed in sequence, and finally N is introduced₂And cooling to room temperature.

2.11, cooling to room temperature, discharging, demolding to obtain a blank target material of zinc telluride doped with zinc, and performing CNC (computer numerical control) processing to obtain the qualified target material of zinc telluride doped with zinc.

The theoretical density of the target material is 5.73g/cm³The actual density was 5.17g/cm³. The relative density is 90.22%.

Example 3

3.1, preparing materials: the mass ratio of ZnTe to Zn Te is 8:1:1(ZnTe purity is 4.5N, Zn purity, 2N, Te purity is 5N).

3.2 mixing materials: introducing nitrogen, charging 20kg of the prepared zinc-doped zinc telluride powder in a 20L PE barrel, adding 4 zirconium balls (diameter of 30CM), and homogenizing for 6h on a rolling homogenizer. The rotating speed of the homogenizer is 60 r/min.

3.3, sintering: first-stage temperature rise: heating from room temperature to 120 deg.C, heating at a heating rate of 5 deg.C/min, heating to 120 deg.C, and holding for 30 min. And (3) heating in the second stage: heating from 120 ℃ to 400 ℃, wherein the heating rate is 5 ℃/min, and keeping the temperature at 400 ℃ for 30 min.

3.4 ball milling: nitrogen was passed through and the zirconium spheres were sized as large (20 cm diameter): medium (15 cm diameter): small (diameter 10cm) ═ 1:1:1, zircon sphere: 1:1, ball-milling and crushing on a ball mill at the rotating speed of 70r/min for 2 h.

3.5 charging: the above ball-milled material was charged into a graphite mold, wherein the size of the charging mold was 208mm × 116mm and the charge was 2 kg.

3.6 pre-pressing the powder for 30min at 25T after feeding the powder into the furnace, opening a rough pumping valve, a mechanical pump and a roots pump in sequence after pre-pressing is finished to vacuumize the furnace body, and starting heating when the vacuum degree of the furnace body is less than 10 Pa.

3.7 first-stage heating: heating from room temperature to 450 deg.C, heating at a heating rate of 5 deg.C/min to 450 deg.C, and maintaining for 60 min.

3.8 second-stage heating: after the first stage is finished, heating to 620 ℃ at the heating rate of 10 ℃/min and preserving the heat for 100 min.

3.9 after the heat preservation, the pressurization is started, the pressurization pressure is 45MPa, the output power of the pressure is 0.5W, and the pressure is maintained for 2h after the pressurization is finished.

3.10 after the pressure is maintained, the natural cooling is started, after the temperature is lower than 450 ℃, the rough pumping valve, the roots pump and the mechanical pump are closed in sequence, and finally N is introduced₂And cooling to room temperature.

3.11, cooling to room temperature, discharging, demolding to obtain a zinc telluride doped blank target, and performing CNC (computer numerical control) processing to obtain the zinc telluride doped target.

The theoretical density of the target material is 5.73g/cm³The actual density was 5.21g/cm³. The relative density is 90.92%.

The performance of the zinc telluride-doped targets obtained in examples 1 to 3 was examined, and the results are shown in table 1.

Test standards: measuring the density by adopting an Archimedes drainage method, and calculating to obtain the relative density by taking the true density as a reference; IPC is adopted to measure the content of impurities, so as to determine the purity of the material; the change of the mass of the sample to be tested during the heating process is tested by thermogravimetric analysis, and the content thereof can be determined by analyzing the temperature point of the change of the characteristic of the substance and the endothermic or exothermic heat in the change of the physical property by a mass change curve to investigate the thermal characteristic of the sample to determine the enthalpy change of the free substance. The resistivity of the material is tested by adopting a four-probe method, the material with low resistivity and high resistance is used for measuring the material with low resistivity and high resistance, the measuring range (0.003-30000 ohm cm) is relatively accurate, the resistivity of less than 10000 ohm cm is excellent, and the conductivity is good.

TABLE 1 detection results of zinc telluride doped target properties

	Resistivity of	Purity of	Free Zn	Relative density
					Standard according to	8000	4.8N	5％	100％
Example 1	4000	4.8N	5.02％	93.71％
					Example 2	19885	4.8N	5.20％	90.22％
Example 3	20953	4.8N	4.45％	90.92％