A tellurium-selenium-zinc plane target material and a preparation method thereof

Abstract

The application discloses a tellurium-selenium-zinc plane target material and a preparation method thereof, and belongs to the technical field of target material processing. The method is characterized in that zinc selenide powder is used to dope zinc telluride powder to prepare a tellurium-zinc-selenium target material, so that the target material can be regulated to a normal temperature band gap of 2.15-2.82 eV, and the material has higher light transmittance than zinc telluride. On the other hand, in order to guarantee the uniformity, compactness and mechanical strength of the target material, the preparation method adopts a double-stage heating and pressurizing method to heat and prepare the powder, so that the prepared tellurium-zinc-selenium plane target material has a relative density of more than 96%, high bending strength and good uniformity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of target material processing, in particular to a tellurium-selenium-zinc plane target material and a preparation method thereof. BACKGROUND

[0002] Zinc telluride is a p-type semiconductor material with high absorption coefficient, and has a wide application prospect in the field of thin film solar sputtering coating. However, the normal temperature band gap of zinc telluride is 2.26eV, which cannot further achieve the expected range of 2.15-2.82eV, and the transmittance of the material to light also needs to be improved.

[0003] In the prior art, doping can be used to modify zinc telluride to regulate its normal temperature band gap, but such doping may affect the physical properties and uniformity of the material itself, and even based on the process difference, the relative density of the material may be low, which cannot meet the use requirements. SUMMARY

[0004] Based on the defects existing in the prior art, the purpose of the present application is to provide a preparation method of a tellurium-selenium-zinc plane target material. The method dopes zinc selenide powder with zinc telluride powder to prepare a zinc tellurium selenium target material, so that the target material can realize normal temperature band gap regulation to the range of 2.15-2.82eV, and the transmittance of the material to light is improved compared with zinc telluride. On the other hand, in order to guarantee the uniformity, compactness and mechanical strength of the target material, the preparation method adopts a double-stage heating and pressing method to heat and prepare the powder, so that the relative density of the prepared zinc tellurium selenium plane target material is more than 96%, and the bending strength is high and the uniformity is good.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A preparation method of a tellurium-selenium-zinc plane target material, comprising the following steps:

[0007] (1) uniformly mix the crushed and sieved zinc selenide powder and zinc telluride powder in a protective atmosphere to obtain a mixed powder;

[0008] (2) load the mixed powder into a mold and heat to 450-550℃ at normal pressure for 30-60min in a heating device, then heat to 880-950℃ at normal pressure for 20-30min, finally maintain the temperature and press to 35-40MPa for 50-80min, and cool, to obtain the tellurium-selenium-zinc plane target material.

[0009] The band gap of zinc selenide at room temperature is 2.7eV, so theoretically, the doping of zinc selenide can change the band gap of zinc telluride at room temperature, and with the increase of selenium concentration, the p-type conductivity of the doped material also increases, however, there are various doping technologies, and different methods for preparing target materials do not consider the purity, uniformity, density and mechanical strength of the target materials, if these basic properties do not meet the requirements, the prepared tellurium selenium zinc target material cannot be applied in practice. Therefore, the technical scheme of the present application prepares a planar target material by a heating and pressurizing method under specific conditions, through two-stage normal pressure heating and heat preservation and finally pressurizing treatment, so that the zinc telluride powder and the zinc selenide powder can be fully doped and reacted and have a high density, and the uniformity of each component is good during the reaction, so that the prepared product can not only realize the theoretical band gap regulation, but also has high bending strength, high relative density and good uniformity, and can be applied in the field of thin film solar sputtering coating.

[0010] Preferably, the sieving mesh number of the zinc selenide powder is 100-150 meshes, and the sieving mesh number of the zinc telluride powder is 100-150 meshes.

[0011] Preferably, the purity of the zinc selenide powder is 5N, and the purity of the zinc telluride powder is 5N.

[0012] Preferably, the atomic ratio of the zinc selenide powder to the zinc telluride powder is (5:5)-(2:8).

[0013] The zinc tellurium selenium with different selenium contents can improve the charge separation efficiency to different degrees, and has different room temperature band gaps, it has been verified that the method can prepare zinc tellurium selenium planar target materials with different doping amounts, and the relative density, uniformity and bending strength of each product can be guaranteed.

[0014] Preferably, the protective atmosphere in the step (1) is at least one of argon and nitrogen, and the mixing time of the zinc selenide powder and the zinc telluride powder is 4-6h.

[0015] More preferably, the mixing is carried out by using a tumbling mixer.

[0016] Preferably, in the step (2), the heating rate during heating is 5-10℃.

[0017] Through analysis, the heating rate during heating has a certain influence on the quality of the product during the heating process of the mixed powder, and the performance of the product is better when the heating rate is maintained within the above preferred range.

[0018] Preferably, in the step (2), the pressurizing rate during pressurizing is 1.8-2.2T / min.

[0019] The analysis shows that the pressing rate during the final stage of the mixed powder has certain influence on the quality of the product, and the performance of the product is better when the pressing rate is maintained within the above-mentioned preferred range.

[0020] Preferably, the mold is a graphite mold.

[0021] Preferably, the heating device is a vacuum hot-pressing furnace.

[0022] Another object of the present application is to provide a tellurium zinc selenide planar target prepared by the preparation method of the tellurium zinc selenide planar target.

[0023] The tellurium zinc selenide planar target can achieve wide normal temperature band gap regulation, and has excellent basic quality, good uniformity, and a relative density of up to more than 98%, and a bending strength of up to nearly 38 MPa.

[0024] The preparation method of the tellurium zinc selenide planar target provided by the present application can achieve normal temperature band gap regulation to the range of 2.15-2.82 eV, and improve the light transmittance of the material compared with zinc telluride; on the other hand, in order to guarantee the uniformity, compactness and mechanical strength of the target, the preparation method adopts a double-stage heating and pressing method to heat and prepare the powder, so that the relative density of the prepared tellurium zinc selenide planar target is more than 96%, and the bending strength is high and the uniformity is good. DETAILED DESCRIPTION

[0025] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with specific examples and comparative examples, the purpose of which is to understand the content of the present application in detail, rather than to limit the present application. All other examples obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. The experimental reagents and instruments involved in the implementation of the present application are all common ordinary reagents and instruments unless otherwise specified.

[0026] Example 1

[0027] An embodiment of the tellurium zinc selenide planar target and the preparation method thereof, the method comprises the following steps:

[0028] (1) 5N grade zinc selenide powder and 5N grade zinc telluride powder after being crushed through a 150 mesh sieve are mixed according to an atomic percentage of 20:80, and are loaded into a tumbling mixer containing argon gas with a flow rate of 5L / min for mixing for 4.5h to be uniform, to obtain a mixed powder;

[0029] (2) the mixed powder is loaded into a graphite mold and heated to 550℃ at a heating rate of 6℃ / min in a vacuum hot-pressing furnace under normal pressure for 40min, then heated to 900℃ at a heating rate of 6℃ / min under normal pressure for 30min, finally, the temperature is kept and the pressure is increased to 40MPa at a pressure increasing rate of 2T / min for 80min, the temperature is decreased to 450℃ and argon is introduced to further decrease the temperature to room temperature, thus the tellurium-zinc-selenium plane target material is obtained.

[0030] Example 2

[0031] An embodiment of the method for preparing the tellurium-zinc-selenium plane target material comprises the following steps:

[0032] (1) 5N grade zinc selenide powder and 5N grade zinc telluride powder after being crushed through a 150 mesh sieve are mixed according to an atomic percentage of 50:50, loaded into a tumbling mixer containing argon with a flow rate of 5L / min, and mixed for 4.5h until uniform, thus the mixed powder is obtained;

[0033] (2) the mixed powder is loaded into a graphite mold and heated to 500℃ at a heating rate of 8℃ / min in a vacuum hot-pressing furnace under normal pressure for 40min, then heated to 920℃ at a heating rate of 10℃ / min under normal pressure for 40min, finally, the temperature is kept and the pressure is increased to 38MPa at a pressure increasing rate of 2T / min for 70min, the temperature is decreased to 450℃ and argon is introduced to further decrease the temperature to room temperature, thus the tellurium-zinc-selenium plane target material is obtained.

[0034] Example 3

[0035] An embodiment of the method for preparing the tellurium-zinc-selenium plane target material comprises the following steps:

[0036] (1) 5N grade zinc selenide powder and 5N grade zinc telluride powder after being crushed through a 150 mesh sieve are mixed according to an atomic percentage of 40:60, loaded into a tumbling mixer containing argon with a flow rate of 5L / min, and mixed for 4.5h until uniform, thus the mixed powder is obtained;

[0037] (2) the mixed powder is loaded into a graphite mold and heated to 450℃ at a heating rate of 10℃ / min in a vacuum hot-pressing furnace under normal pressure for 40min, then heated to 880℃ at a heating rate of 10℃ / min under normal pressure for 30min, finally, the temperature is kept and the pressure is increased to 42MPa at a pressure increasing rate of 2T / min for 60min, the temperature is decreased to 450℃ and argon is introduced to further decrease the temperature to room temperature, thus the tellurium-zinc-selenium plane target material is obtained.

[0038] Example 4

[0039] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 3°C / min.

[0040] Example 5

[0041] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0042] Example 6

[0043] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0044] Example 7

[0045] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0046] Comparative Example 1

[0047] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0048] Comparative Example 2

[0049] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0050] Comparative Example 3

[0051] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0052] Comparative Example 4

[0053] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0054] Comparative Example 5

[0055] An embodiment of the Te-Se-Zn plane target and the method for manufacturing the same according to the present invention differs from the embodiment 1 only in that the temperature increasing rate in the step (2) is 12°C / min.

[0056] Comparative Example 6

[0057] One embodiment of the Te-Se-Zn plane target material and the preparation method thereof according to the present application differs from Example 1 only in that the temperature of the first heat preservation is 400℃ and the heat preservation time is 70 min.

[0058] Comparative Example 7

[0059] One embodiment of the Te-Se-Zn plane target material and the preparation method thereof according to the present application differs from Example 1 only in that the temperature of the first heat preservation is 600℃ and the heat preservation time is 20 min.

[0060] Comparative Example 8

[0061] One embodiment of the Te-Se-Zn plane target material and the preparation method thereof according to the present application differs from Example 1 only in that the step (2) is:

[0062] (2) The mixed powder is loaded into a graphite mold and heated to 900℃ at a heating rate of 6℃ / min in a vacuum hot-pressing furnace under normal pressure, and then heat preserved for 70 min, finally kept at the temperature and pressurized to 40 MPa at a pressurizing rate of 2T / min for 80 min, cooled to 450℃ and further cooled to room temperature by introducing argon, thus obtaining the Te-Se-Zn plane target material of Example 1

[0063] In order to verify the quality of the Te-Se-Zn plane target material according to the present application, the relative density of each Te-Se-Zn plane target material is tested, and then the bending strength of each product is tested according to the standard method of GB / T 4741-1999, and the results are shown in Table 1.

[0064] Table 1

[0065]

[0066] The element content uniformity is calculated from the average value and the variance, and the coefficient of variation of Examples 1-3 is less than 10%, so the material uniformity is high. As can be clearly seen from Table 1, the Te-Se-Zn plane target material according to the present application has high uniformity, and the product has high relative density and good bending strength, and can be directly applied in the field of sputtering thin films. In contrast, the products prepared by the methods of Comparative Examples 1-7 using the same raw materials do not meet the normal standards in terms of relative density, bending strength or uniformity, fully demonstrating that the selection of the two-stage heat preservation and pressurization preservation processes and the selection of the parameters are crucial in the process of preparing the Te-Se-Zn target material by doping zinc telluride and zinc selenide, and the change of the process or the adjustment of the parameters can greatly reduce the quality performance of the target material itself. According to the comparison between Example 1 and Examples 4-7, it can be seen that the heating rate and the pressurizing rate in the process also have certain influence on the quality of the product, and the optimal heating rate is 5-10℃ / min and the optimal pressurizing rate is 1.8-2.2T / min.

[0067] Then, the products of each example are tested for uniformity. The testing method is: according to the three-point method to test the uniformity of the distribution of the content of the element (selenium element), the content of the element is measured by weight method, and the uniformity of the content of the element is measured by the coefficient of variation calculated from the average value and the variance. It is found that the calculated coefficient of variation of each product is less than 10%, which indicates that the uniformity of each product is high, and there is no problem of uneven element doping which often occurs in the products prepared by the existing doping process.

[0068] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A method for preparing a zinc telluride selenide planar target, characterized in that: The following steps are involved: (1) Mixing the crushed and sieved zinc selenide powder and zinc telluride powder evenly under a protective atmosphere to obtain a mixed powder; (2) The mixed powder is placed in a mold and heated to 450-550°C at normal pressure in a heating device and kept at this temperature for 30-60 minutes. Then, the mixed powder is heated to 880-950°C at normal pressure and kept at this temperature for 20-30 minutes. Finally, the mixed powder is pressurized to 35-40 MPa and kept at this temperature for 50-80 minutes. The mixed powder is cooled to obtain the zinc telluride selenide planar target. The heating rate during heating is 5-10°C / min, and the pressurization rate during pressurization is 1.8-2.2T / min.

2. The method for preparing a zinc telluride and selenide planar target according to claim 1, wherein: The mesh number of the zinc selenide powder is 100-150 mesh, and the mesh number of the zinc telluride powder is 100-150 mesh.

3. The method for preparing a zinc telluride and selenide planar target according to claim 1, wherein: The atomic ratio of the zinc selenide powder to the zinc telluride powder is (5:5) to (2:8).

4. The method for preparing a zinc telluride and selenide planar target according to claim 1, wherein: In the step (1), the protective atmosphere is at least one of argon and nitrogen, and the mixing time of the zinc selenide powder and the zinc telluride powder is 4 to 6 hours.

5. A zinc telluride and selenide planar target prepared by the method for preparing a zinc telluride and selenide planar target according to any one of claims 1 to 4.

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