High-density nickel oxide-based rotating target material and method for manufacturing the same

Abstract

The application discloses a kind of high-density nickel oxide-based rotary target material and preparation method thereof, the rotary target material includes nickel oxide and doped oxide, the mass fraction of the nickel oxide is not less than 95.0wt%, the total mass fraction of doped oxide is not higher than 7.5wt%, the doped oxide is selected from at least two of zinc oxide, strontium oxide, tin oxide, and the mass fraction range of the corresponding oxide is selected as follows: 0.1~1.0wt% of zinc oxide, 0.1~1.5wt% of strontium oxide, 0.1~5.0wt% of tin oxide.The nickel oxide rotary target material of the application is prepared by using nickel oxide powder and doped oxide powder as raw materials, through the steps of granulation, cold isostatic pressing, low-temperature normal-pressure segmented sintering and furnace cooling, and the rotary target material is obtained.The application adopts low-temperature normal-pressure segmented sintering to prepare high-density rotary target material with a relative density of more than 99.29%.The nickel oxide rotary target material of the application has good compactness and low cost, and can be applied to mass production of perovskite solar cell.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of a nickel oxide-based rotary target material, in particular to a high-density nickel oxide-based rotary target material and a preparation method thereof. BACKGROUND

[0002] At present, a perovskite solar cell has become a research hotspot in the photovoltaic industry and attracted much attention. Nickel oxide is used as a hole transport layer material and is widely applied to the perovskite solar cell because of its advantages. The nickel oxide film layer has high carrier mobility, can effectively improve the transmission of electrons and holes between the electron transport layer and the hole transport layer in the use process of the perovskite solar cell, has high transmittance and good film layer stability, and has a good effect on the performance improvement of the perovskite solar cell. The nickel oxide layer is mostly used in a p-i-n type planar perovskite solar cell, but the photoelectric conversion efficiency of the nickel oxide-based perovskite solar cell is still lower than that of the PEDOT:PSS-based perovskite solar cell. The main reason is that the conductivity of the nickel oxide film is not high, the interface contact between the nickel oxide substrate and the perovskite film is poor due to the low-temperature film forming mode such as spin coating or sol-gel, and the crystallinity and quality of the perovskite film grown on the nickel oxide substrate are poor.

[0003] In view of the low open-circuit voltage and short-circuit current of the p-i-n type perovskite solar cell based on the nickel oxide hole transport layer, ion doping is mainly used to improve the electrical properties of the NiO in the prior art, but there are certain problems in the test process of the nickel oxide-based perovskite solar cell. The main performances are poor film layer stability, low photoelectric conversion efficiency and the like. The stability of the nickel oxide film layer is closely related to the uniformity of the film layer. The low density of the nickel oxide target material and the many pores or defects in the target material will directly affect the uniformity of the target material film. At present, it is difficult to produce a high-density nickel oxide target material. For example, CN115650701B discloses a preparation method and application of a nickel oxide-based target material. Nickel oxide powder with a fixed specific surface area of 7m 2 / g~9m 2 / g and niobium oxide powder, wherein the doping amount of the niobium oxide is 2.0wt%, and the target sintering temperature is 1450 DEG C. The highest relative density of the target material is only 98.5%.

[0004] It can be known from market application that the utilization rate of a planar target material is only about 30%, while the utilization rate of a rotary target material can be more than 80%. Therefore, the utilization rate of the rotary target material is more than 2.5 times that of the planar target material. From the production cost, the rotary target material is more conducive to industrial use.

[0005] Therefore, there is an urgent need for a high-density nickel oxide rotary target material which can be produced at low cost and realizes industrialized mass production. SUMMARY

[0006] In order to solve the problems in the prior art, the application provides a high-density nickel oxide-based rotary target and a preparation method thereof. The doping oxide in the application is selected from at least two of zinc oxide, strontium oxide and tin oxide. The high-density rotary target with a relative density of more than 99.29% can be prepared by low-temperature and low-pressure step-by-step sintering. The nickel oxide rotary target prepared by the application has good compactness and low cost, and can be applied to mass production of perovskite solar cell sheets.

[0007] In order to achieve the above-mentioned purpose, the application adopts the following specific scheme:

[0008] In one aspect, the application provides a high-density nickel oxide-based rotary target, characterized in that the target comprises nickel oxide and doping oxide, the total mass fraction of the doping oxide is not higher than 7.5wt%, and the doping oxide is selected from at least two of zinc oxide, strontium oxide and tin oxide, and the mass fraction ranges of the corresponding oxides are as follows: 0.1-1.0wt% of zinc oxide, 0.1-1.5wt% of strontium oxide and 0.1-5.0wt% of tin oxide.

[0009] Further, the mass fraction of the nickel oxide is not less than 95.0wt%.

[0010] In another aspect, the application discloses a preparation method of a high-density nickel oxide-based rotary target. The target is prepared by using nickel oxide powder and doping oxide powder as raw materials, and by performing the steps of granulation, cold isostatic pressing, low-temperature and normal-pressure step-by-step sintering and furnace cooling.

[0011] The doping oxide is selected from at least two of zinc oxide, strontium oxide and tin oxide.

[0012] Further, the raw material nickel oxide powder is composed of micron powder and nano powder, and the mass ratio of the micron powder to the nano powder is (87-93):(13-7). The specific surface area of the micron powder is 1-2m 2 / g, and the specific surface area of the nano powder is 12-18m 2 / g.

[0013] Further, the particle size of the doping oxide is 200-500nm, and the purity is more than 4N.

[0014] Further, the pressure used in the cold isostatic pressing is 150-250Mpa.

[0015] Further, the low-temperature and normal-pressure step-by-step sintering comprises one-step sintering and two-step sintering, and the specific parameters are as follows: the sintering temperature in the one-step sintering is 400-600℃, the holding time is 3-10h, and the sintering pressure is 0-100pa.

[0016] The sintering temperature in the second sintering is 1200-1300 DEG C, and the time is 5-12 hours, nitrogen-hydrogen mixed gas is passed through the whole process in the second sintering, and the sintering pressure is 100-500 pa.

[0017] Further, the furnace pressure is kept at 50-200 Pa during the furnace cooling.

[0018] Beneficial effects:

[0019] 1) The zinc oxide, strontium oxide and tin oxide are doped in the application, the zinc oxide can help the target material to grow at the sintering temperature of about 1200 DEG C, promote the grain growth of the target material, the tin oxide can effectively improve the conductivity of the target material, and the strontium oxide can ensure the reduction of pores in the sintering process of the target material and improve the density of the target material.

[0020] 2) In the sintering step of the preparation of the nickel oxide-based rotary target material, long-time sintering is adopted at a low temperature (about 400-600 DEG C), which can not only make the target material initially form, but also facilitate the degumming of the target material, and then long-time sintering is adopted at a high temperature (1200-1300 DEG C), and nitrogen-hydrogen mixed gas is passed through the whole process in the sintering process, which can not only ensure the density of the target material, but also facilitate the removal of some impurities. Moreover, on the basis of ensuring the performance of the target material, the low-temperature normal-pressure segmented sintering can effectively save the production cost.

[0021] 3) When the nickel oxide powder in the application is single micron powder, the sintering activity of the formed green body is low, and the target material has a low density when discharged. When the nickel oxide powder is single nano powder, the sintering activity of the formed green body is high, and the target material has a high risk of cracking. The micron powder and the nano powder are mixed in the application, which can effectively improve the sintering activity of the micron powder, greatly improve the activation energy of the powder particles, reduce the sintering temperature, make the target material have smaller grains and higher density under the same sintering process, reduce the defect rate and cracking risk of the target material, and improve the sintering density of the target material.

[0022] 4) The raw material of the nickel oxide rotary target material in the application is the nickel oxide mixed with trace amounts of doped oxides, and the low-temperature low-pressure segmented sintering can manufacture the nickel oxide rotary target material with a relative density of more than 99.29%, so as to ensure the stability of the nickel oxide film layer. The utilization rate of the nickel oxide rotary target material is high, and the production cost is greatly reduced. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present application.

[0024] The present application provides a high-density nickel oxide-based rotating target and a preparation method thereof. The rotating target comprises nickel oxide and doped oxides. The mass fraction of the nickel oxide is not less than 95.0 wt%, and the total mass fraction of the doped oxides is not higher than 7.5 wt%. The doped oxides are selected from at least two of zinc oxide, strontium oxide and tin oxide, and the mass fraction ranges of the corresponding oxides are as follows: 0.1-1.0 wt% for zinc oxide, 0.1-1.5 wt% for strontium oxide, and 0.1-5.0 wt% for tin oxide.

[0025] The preparation method of the nickel oxide-based rotating target mainly comprises the following steps:

[0026] Step one: a fixed mass of deionized water is weighed, and an appropriate amount of dispersant is added. Then, nickel oxide and doped oxides (at least two of zinc oxide, strontium oxide and tin oxide) are weighed and mixed by pre-dispersing and fully stirring. Then, ball milling is performed in a grinding machine for a certain time. An appropriate amount of dispersant and binder is added during the process. After the D50 of the slurry is less than 200 nm, a specific granulation process is used in a spray dryer to form granules. The granules formed by the spray drying instrument are spherical particles with uniform size. The granules are sieved using a 80-mesh to 120-mesh screen to obtain experimental granules.

[0027] Step two: the experimental granules are loaded into a specific blank forming mold, and a cold isostatic pressing machine is used to press the granules at a pressure of 150 MPa to 250 MPa for 30 minutes to 50 minutes to obtain a blank target.

[0028] Step three: the blank target after pressing is subjected to low-temperature normal-pressure segmented sintering. After sintering, the target is cooled to room temperature in the furnace to obtain a nickel oxide-based rotating target.

[0029] In the first-stage sintering, the sintering temperature is 400℃ to 600℃, the holding time is 3h to 10h, and the sintering pressure is 0pa to 100pa. In the second-stage sintering, the sintering temperature is 1200℃ to 1300℃, the sintering time is 5h to 12h, nitrogen-hydrogen mixed gas is introduced during the whole process of the second-stage sintering, and the sintering pressure is 100pa to 500pa. The heating rate from the first-stage sintering temperature to the second-stage sintering temperature is 0.3℃ / min to 1.0℃ / min, and the furnace pressure is maintained at 50pa to 200pa during the cooling process.

[0030] Preferably, in step one, the mass ratio of micron powder to nano powder in the nickel oxide raw material is (87-93):(13-7), the specific surface area of micron powder is 1-2 m 2 / g, and the specific surface area of nano powder is 12-18 m 2 / g. The doped oxide is nano powder with a particle diameter of 200-500 nm, and the purity of the doped oxide is strictly controlled to be above 4N.

[0031] In step one, the amount of deionized water added is determined according to the pre-added amount of the oxide, and the solid content of the slurry is controlled to be 40%-60%.

[0032] Preferably, in step one, the dispersant used in the application is ammonium polyacrylate, and the mass ratio of the amount of dispersant added to the amount of oxide in the pre-dispersion process is 0.8%-1.2%.

[0033] Preferably, in step one, the pre-dispersion process is controlled to last for 2-5 hours, and the ball milling process is controlled to last for 3-6 hours. Zirconium oxide balls with a diameter of 300-500 μm are used for ball milling.

[0034] Preferably, in step one, the mass ratio of the amount of dispersant added to the amount of oxide in the ball milling process is 1.5%-3.5%.

[0035] Preferably, in step one, the binder used in the application is polyvinyl alcohol, and the mass ratio of the amount of binder added to the amount of oxide is 1.5%-2.5%.

[0036] Preferably, in step one, the inlet and outlet air temperature parameters of the spray drying instrument are 175-195℃ and 75-90℃, respectively.

[0037] Preferably, in step three, the volume ratio of nitrogen to hydrogen in the nitrogen-hydrogen mixed gas is (98.0-99.5):(2.0-0.5).

[0038] The technical solutions of the application will be described in detail below with reference to specific embodiments.

[0039] Embodiment 1

[0040] The preparation method of the nickel oxide-based rotary target mainly includes the following steps

[0041] Step one, mix nickel oxide (micron powder and nanometer powder mass ratio is 90:10) with doped oxide whose particle diameter is less than 300 nm, pre-disperse, pre-disperse for 3 hours, then ball mill the slurry, strictly monitor the change of D50 of the slurry, when D50 is less than 200 nm, end the grinding, after the grinding, use a spray dryer to granulate, the inlet air temperature of the spray dryer is 190 ℃, the outlet air temperature is 85 ℃, after the granulation, use a 100 mesh screen to sieve the particles to obtain experimental particles; wherein the solid content of the slurry in the pre-dispersing process is 50%, the amount of dispersant added is 1.0%, and the amount of binder added is 2.0%; wherein the mass fraction of nickel oxide is 99.4%, the mass fraction of zinc oxide is 0.1%, and the mass fraction of strontium oxide is 0.5%;

[0042] Step two, use a specific blank forming mold to pack the obtained experimental particles, and use a cold isostatic pressing machine to press to obtain a blank target material; the pressure parameter of the cold isostatic pressing machine is 220 MPa, and the time is 40 min.

[0043] Step three, low-temperature normal-pressure segmented sintering is performed on the blank after the pressing is completed; the sintering temperature of the first sintering is 550 ℃, the heating rate is 0.5 ℃ / min, and the sintering pressure is 60 pa-70 pa; the sintering temperature of the second sintering is 1250 ℃, the holding time is 8 h, the heating rate is 0.75 ℃ / min, and the sintering pressure is 300 pa-350 pa; nitrogen-hydrogen mixed gas is introduced during the second sintering process, and the volume ratio of nitrogen to hydrogen in the nitrogen-hydrogen mixed gas is 99:1.

[0044] Step four, after the sintering is completed, furnace cooling is performed at a cooling rate of 1.5 ℃ / min, the pressure in the furnace is maintained at 80 pa-100 pa during the cooling process, and after the cooling is completed and the target material is taken out of the furnace, the target material is processed to obtain a nickel oxide target material.

[0045] Example 2

[0046] The difference between this example and Example 1 is that the mass fraction of nickel oxide in Step one is 98.9%, the mass fraction of zinc oxide is 0.1%, and the mass fraction of strontium oxide is 1.0%. The rest is the same as Example 1.

[0047] Example 3

[0048] The difference between this example and Example 1 is that the mass fraction of nickel oxide in Step one is 98.4%, the mass fraction of zinc oxide is 0.1%, and the mass fraction of strontium oxide is 1.5%. The rest is the same as Example 1.

[0049] Example 4

[0050] The difference between this example and Example 1 is that the mass fraction of nickel oxide in Step 1 is 98.9%, the mass fraction of zinc oxide is 0.1%, and the mass fraction of tin oxide is 1.0%. The rest is the same as Example 1.

[0051] Example 5

[0052] The difference between this example and Example 1 is that the mass fraction of nickel oxide in Step 1 is 97.9%, the mass fraction of zinc oxide is 0.1%, and the mass fraction of tin oxide is 2.0%. The rest is the same as Example 1.

[0053] Example 6

[0054] The difference between this example and Example 1 is that the mass fraction of nickel oxide in Step 1 is 96.9%, the mass fraction of zinc oxide is 0.1%, and the mass fraction of tin oxide is 3.0%. The rest is the same as Example 1.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 2 is that the sintering temperature of the two-stage sintering in Step 3 is adjusted to 1400°C. The rest is the same as Example 2.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 2 is that the sintering temperature of the two-stage sintering in Step 3 is adjusted to 1100°C. The rest is the same as Example 2.

[0059] Comparative Example 3

[0060] The difference between this comparative example and Example 2 is that only zinc oxide is used as a doping oxide in Step 1. The rest is the same as Example 2.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 2 is that the nickel oxide raw material in Step 1 uses a single micron powder. The rest is the same as Example 2.

[0063] Comparative Example 5

[0064] The difference between this comparative example and Example 2 is that the nickel oxide raw material in Step 1 uses a single nanometer powder. The rest is the same as Example 2.

[0065] Performance Test

[0066] Target density detection: calculated according to the Archimedes principle and the theoretical density of the target material.

[0067] Target resistance detection: using a multimeter with a fixed distance between the two probes.

[0068] The target materials prepared according to Examples 1-6 and Comparative Examples 1-5 were subjected to performance tests, and the results are shown in Table 1.

[0069] Table 1: Performance test results of target materials of Examples 1-6 and Comparative Examples 1-5

[0070]

[0071] According to Table 1, the following conclusions can be drawn: (1) According to Examples 1-6, the density of the nickel oxide rotating target prepared according to the present application is above 99.29%, which can effectively improve the use effect of the target film; (2) According to Examples 1-3, with the increase of the doping amount of strontium oxide, the density of the target material is improved; (3) According to Examples 4-6, the doping of tin oxide helps to improve the density of the target material, but the effect is lower than that of strontium ions; (4) According to Example 2 and Comparative Example 1, the increase of the sintering temperature improves the density of the target material, but due to the high sintering temperature, the change of the grain structure during the sintering process of the target material is different, which causes cracks in the target material; (5) According to Example 2 and Comparative Example 2, the decrease of the sintering temperature causes incomplete growth of the internal grains of the target material, which affects the density of the target material and reduces the relative density of the target material; (6) According to Example 2 and Comparative Example 3, under the condition of zinc oxide doping alone, the density of the target material is greatly affected; (7) According to Example 2 and Comparative Examples 5-6, the doping and sintering of a certain proportion of micron powder and nano powder helps to improve the density of the target material and effectively reduces the risk of sintering cracking of the target material.

[0072] The above description is only a preferred embodiment of the present application, and is not intended to limit the present application in any form. Any equivalent transformation or modification according to the essence of the present application should be covered within the protection scope of the present application.

Claims

1. A high-density nickel oxide-based rotating target material, characterized by, The total mass fraction of the nickel oxide and the doped oxide is not higher than 7.5 wt%, the doped oxide is selected from at least two of zinc oxide, strontium oxide and tin oxide, and the mass fraction ranges of the corresponding oxides are 0.1-1.0 wt% for zinc oxide, 0.1-1.5 wt% for strontium oxide and 0.1-5.0 wt% for tin oxide; The preparation method of the high-density nickel oxide-based rotary target material is as follows: taking nickel oxide powder and doped oxide powder as raw materials, performing granulation, cold isostatic pressing, low-temperature normal-pressure step-by-step sintering and in-furnace cooling, and then obtaining the rotary target material. The raw material nickel oxide powder is composed of micron powder and nano powder, the mass ratio of the micron powder to the nano powder is (87-93):(13-7); the specific surface area of the micron powder is 1-2 m 2 / g, and the specific surface area of the nano powder is 12-18 m 2 / g. The low-temperature normal-pressure step-by-step sintering includes one-step sintering and two-step sintering, and the specific parameters are as follows: The sintering temperature of the one-step sintering is 400-600 DEG C, the holding time is 3-10 h, and the sintering pressure is 0-100 pa. The sintering temperature of the two-step sintering is 1200-1300 DEG C, the time is 5-12 h, nitrogen-hydrogen mixed gas is introduced during the whole two-step sintering process, and the sintering pressure is 100-500 pa.

2. The high-density nickel oxide-based rotating target according to claim 1, wherein The mass fraction of the nickel oxide is not less than 95.0 wt%.

3. The high-density nickel oxide-based rotating target according to claim 1, wherein The particle size of the doped oxide is 200-500 nm, and the purity is higher than 4N.

4. The high-density nickel oxide-based rotating target according to claim 1, wherein The pressure used in the cold isostatic pressing is 150-250 MPa.

5. The high density nickel oxide-based rotating target of claim 1, wherein, The pressure in the furnace during the in-furnace cooling is kept at 50-200 Pa.

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