Chlorine-doped nickel oxide, preparation method and application thereof, and photoelectric device

Abstract

The invention provides chlorine-doped nickel oxide, a preparation method and application thereof and a photoelectric device, and relates to the field of photoelectric materials.The preparation method of the chlorine-doped nickel oxide comprises the following steps that S10, an aqueous solution of nickel salt and chlorine salt is obtained, an alkaline solution is dropwise added, centrifugation is conducted, and a coprecipitate is obtained; s20, washing, drying and roasting the coprecipitate to obtain chlorine-doped nickel oxide; wherein the molar ratio of the nickel salt to the chlorine salt is (10-20): (1-4). In the technical scheme provided by the invention, the nickel salt and the chlorine salt are co-precipitated to generate a co-precipitate of nickel hydroxide and chloride, and then the co-precipitate is washed, dried and roasted to prepare the chlorine-doped nickel oxide, so that the hole mobility of the chlorine-doped nickel oxide is improved; the alkaline solution is dropwise added for coprecipitation, so that the particle size of the coprecipitate can be reduced, and the nanoscale chlorine-doped nickel oxide is prepared, so that the dispersity of the chlorine-doped nickel oxide in a mobile phase is improved, and the chlorine-doped nickel oxide can be applied to preparation of a hole transport film and improvement of the uniformity of the hole transport film.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric materials, and in particular to chlorine-doped nickel oxide, a preparation method and application thereof, and a photoelectric device. Background Art

[0002] Nickel oxide has a unique 3d electronic structure and Ni 2+ Vacancies have good electron blocking properties and hole transport capabilities, and are therefore widely used in organic optoelectronic devices. The dense and smooth nano-nickel oxide film significantly improves the performance of solar cells.

[0003] However, the nickel oxide produced by the existing nickel oxide synthesis method has a low hole concentration, resulting in low conductivity. Excessively low conductivity will lead to a reduced fill factor, which in turn leads to a decrease in the overall efficiency of optoelectronic devices containing nickel oxide. Summary of the Invention

[0004] The main purpose of the present invention is to provide a chlorine-doped nickel oxide and its preparation method and application, as well as a photoelectric device, in order to solve the problem of low hole concentration in nickel oxide produced by the existing nickel oxide synthesis method.

[0005] To achieve the above object, the present invention provides a method for preparing chlorine-doped nickel oxide, comprising the following steps:

[0006] S10. Obtain an aqueous solution of nickel salt and chloride salt, add alkaline solution dropwise, and centrifuge to obtain a coprecipitate;

[0007] S20. The coprecipitate is washed, dried, and calcined to obtain chlorine-doped nickel oxide;

[0008] Wherein, the molar ratio of the nickel salt to the chloride salt is (10-20): (1-4).

[0009] In one embodiment, in the aqueous solution of nickel salt and chloride salt, the nickel salt is a monobasic nickel salt, and the chloride salt is a monobasic chloride salt;

[0010] The molar ratio of the monobasic nickel salt to the monobasic chloride salt is 20:(1-4).

[0011] In one embodiment, in the aqueous solution of nickel salt and chloride salt, the nickel salt comprises nickel nitrate, and the chloride salt comprises potassium chloride;

[0012] The molar ratio of nickel nitrate to potassium chloride is 20:(1-4);

[0013] The molar concentration of nickel nitrate is 0.8 to 1.2 mol / L.

[0014] In one embodiment, the alkaline solution includes a monobasic base, and the molar ratio of the monobasic base to the nickel salt is 2:(3-5).

[0015] In one embodiment, the monobasic alkali is sodium hydroxide, and the concentration of sodium hydroxide in the alkaline solution is 9-11 mol / L.

[0016] In one embodiment, in step S10, the centrifugal speed is 4000-6000 rpm, and the centrifugal time is 5-10 min; and / or,

[0017] In step S20, the drying step adopts vacuum drying, the vacuum drying temperature is 15 to 25° C., the vacuum degree of vacuum drying is between -0.08 and -0.1 MPa, and the vacuum drying time is 8 to 24 hours; and / or,

[0018] In step S20, the calcination temperature is 250-300°C, and the calcination time is 2-4 hours.

[0019] The present invention also provides a chlorine-doped nickel oxide, comprising the chlorine-doped nickel oxide prepared according to the above-mentioned preparation method of the chlorine-doped nickel oxide.

[0020] The present invention also provides an application of chlorine-doped nickel oxide in a photoelectric device. The chlorine-doped nickel oxide includes the chlorine-doped nickel oxide as described above.

[0021] The present invention further provides a photoelectric device comprising a hole transport material, wherein the hole transport material comprises the chlorine-doped nickel oxide as described above.

[0022] In one embodiment, the optoelectronic device includes a perovskite solar cell; the perovskite solar cell includes a substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode layer stacked in sequence, and the hole transport layer includes the chlorine-doped nickel oxide.

[0023] In the technical solution of the present invention, a nickel salt and a chloride salt are co-precipitated to generate a co-precipitate of nickel hydroxide and chloride, which is then washed, dried, and calcined to obtain chlorine-doped nickel oxide, thereby improving the hole mobility of the chlorine-doped nickel oxide. The co-precipitation is performed by dropwise adding an alkaline solution to reduce the particle size of the co-precipitate, thereby obtaining nano-scale chlorine-doped nickel oxide, thereby improving the dispersibility of the chlorine-doped nickel oxide in a mobile phase. The chlorine-doped nickel oxide can be directly used to prepare a thin film, thereby improving the uniformity of the hole transport thin film. The chlorine doping amount can be adjusted by adjusting the molar ratio of the nickel salt to the chloride salt. If the chlorine doping amount is too low, the hole content of the chlorine-doped nickel oxide is low. If the chlorine doping amount is too high, the dispersion rate of the chlorine-doped nickel oxide in water is low, and the uniformity of the formed chlorine-doped nickel oxide thin film is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a physical picture of the chlorine-doped nickel oxide provided by Examples 1 to 3 of the present invention and the nickel oxide provided by Comparative Example 1 dissolved in water;

[0026] Figure 2 This is a graph showing the X-ray photoelectron spectroscopy analysis results of the chlorine-doped nickel oxide provided in Example 2 of the present invention and the nickel oxide provided in Comparative Example 1;

[0027] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0029] It should be noted that, in the embodiments, those without specifying specific conditions, are carried out according to conventional conditions or the conditions recommended by the manufacturer. Those for reagents or instruments used that do not specify the manufacturer are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes schemes A, B, or A and B that meet the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on those of ordinary skill in the art. When the combination of the technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work belong to the scope of protection of the present invention.

[0030] Nickel oxide has a unique 3d electronic structure and Ni 2+ Vacancies have good electron blocking properties and hole transport capabilities, and are therefore widely used in organic optoelectronic devices. The dense and smooth nano-nickel oxide film significantly improves the performance of solar cells.

[0031] Currently, the nickel oxide produced by the existing nickel oxide synthesis method has a low hole concentration, resulting in low conductivity. Excessively low conductivity will lead to a reduced fill factor, which in turn leads to a decrease in the overall efficiency of optoelectronic devices containing nickel oxide.

[0032] In view of this, the present invention proposes a method for preparing chlorine-doped nickel oxide, comprising the following steps:

[0033] S10. Obtain an aqueous solution of nickel salt and chloride salt, add alkaline solution dropwise, and centrifuge to obtain a coprecipitate;

[0034] S20. The coprecipitate is washed, dried, and calcined to obtain chlorine-doped nickel oxide;

[0035] Wherein, the molar ratio of the nickel salt to the chloride salt is (10-20): (1-4).

[0036] In the technical solution of the present invention, a nickel salt and a chloride salt are co-precipitated to generate a co-precipitate of nickel hydroxide and chloride, which is then washed, dried, and calcined to obtain chlorine-doped nickel oxide, thereby improving the hole mobility of the chlorine-doped nickel oxide. The co-precipitation is performed by dropwise adding an alkaline solution to reduce the particle size of the co-precipitate, thereby obtaining nano-scale chlorine-doped nickel oxide, thereby improving the dispersibility of the chlorine-doped nickel oxide in a mobile phase. The chlorine-doped nickel oxide can be directly used to prepare a thin film, thereby improving the uniformity of the hole transport thin film. The chlorine doping amount can be adjusted by adjusting the molar ratio of the nickel salt to the chloride salt. If the chlorine doping amount is too low, the hole content of the chlorine-doped nickel oxide is low. If the chlorine doping amount is too high, the dispersion rate of the chlorine-doped nickel oxide in water is low, and the uniformity of the formed chlorine-doped nickel oxide thin film is low.

[0037] In one embodiment, in the aqueous solution of nickel salt and chloride salt, the nickel salt is a monobasic nickel salt, and the chloride salt is a monobasic chloride salt; the molar ratio of the monobasic nickel salt to the monobasic chloride salt is 20:(1-4).

[0038] In the technical solution of the present invention, the ratio of nickel and chlorine can be adjusted by adjusting the molar ratio of nickel nitrate and potassium chloride, thereby adjusting the chlorine doping amount. Appropriate chlorine doping can improve the porosity and conductivity of nickel oxide. If the amount of potassium chloride added is too high, it will inhibit the formation of nano-sized nickel hydroxide, resulting in reduced dispersibility. Specifically, in some embodiments of the present invention, the nickel salt is nickel nitrate hexahydrate.

[0039] In one embodiment, in the aqueous solution of nickel salt and chloride salt, the nickel salt includes nickel nitrate, and the chloride salt includes potassium chloride; the molar ratio of nickel nitrate to potassium chloride is 20:(1-4); and the molar concentration of nickel nitrate is 0.8-1.2 mol / L.

[0040] In the technical solution of the present invention, by adopting nickel nitrate and potassium chloride co-precipitation, impurities in the co-precipitate can be reduced, thereby improving the purity of chlorine-doped nickel oxide and ensuring the photoelectric performance of chlorine-doped nickel oxide; by adjusting the molar concentration of nickel nitrate, the content of nickel ions in the solution is adjusted, so that nickel hydroxide precipitate can be quickly generated in the subsequent step.

[0041] In one embodiment, the alkaline solution includes a monobasic base, and the molar ratio of the monobasic base to the nickel salt is 2:(3-5).

[0042] In the technical solution of the present invention, by adopting a monobasic base and adjusting the molar ratio of the monobasic base to the nickel salt, the amount of base used in the nickel salt can be adjusted, thereby ensuring that most of the nickel salt forms sodium hydroxide precipitate, while reducing the alkaline precipitation of other cations, increasing the content of nickel salt in the coprecipitate, and reducing the doping of miscellaneous elements.

[0043] In one embodiment, the monobasic alkali is sodium hydroxide, and the concentration of sodium hydroxide in the alkaline solution is 9-11 mol / L.

[0044] In the technical solution of the present invention, the coprecipitation speed can be adjusted by adjusting the concentration of the sodium hydroxide solution. If the concentration of the sodium hydroxide solution is too high, the precipitation speed is too fast and the particle size of the coprecipitate is too large. If the concentration of the sodium hydroxide solution is too low, the precipitation speed is too slow, and too much water is added, chloride in the coprecipitate is dissolved, the chlorine doping amount is reduced, and the porosity of the chlorine-doped nickel oxide is reduced. By adjusting the molar ratio of nickel nitrate and sodium hydroxide, the amount of sodium hydroxide is adjusted to ensure that most of the nickel in the aqueous solution of the nickel salt and the chloride salt forms the coprecipitate.

[0045] In one embodiment, in step S10, the centrifugal speed is 4000-6000 rpm, and the centrifugal time is 5-10 min; and / or, in step S20, the drying step adopts vacuum drying, the vacuum drying temperature is 15-25° C., the vacuum degree of vacuum drying is between -0.08 and -0.1 MPa, and the vacuum drying time is 8-24 h; and / or, in step S20, the roasting temperature is 250-300° C., and the roasting time is 2-4 h.

[0046] In the technical solution of the present invention, the coprecipitate can be separated from the solution by adjusting the centrifugal speed and centrifugal time; the moisture on the surface of the coprecipitate can be quickly removed by vacuum drying; the side reaction between the coprecipitate and moisture at high temperature can be reduced by adjusting the vacuum drying temperature to 15-25°C, thereby improving the purity of the generated chlorine-doped nickel oxide; and the nickel hydroxide in the coprecipitate can be roasted to generate nickel oxide by adjusting the roasting temperature and time, while further reducing the moisture content.

[0047] The present invention also provides a chlorine-doped nickel oxide, comprising the chlorine-doped nickel oxide prepared according to the above-mentioned preparation method of the chlorine-doped nickel oxide.

[0048] Since the chlorine-doped nickel oxide adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0049] The present invention also provides an application of chlorine-doped nickel oxide in a photoelectric device. The chlorine-doped nickel oxide includes the chlorine-doped nickel oxide as described above.

[0050] In the technical solution of the present invention, chlorine-doped nickel oxide is applied to a photoelectric device to promote carrier separation, reduce series resistance, and increase fill factor, thereby improving the power conversion efficiency of the photoelectric device.

[0051] The present invention further provides a photoelectric device comprising a hole transport material, wherein the hole transport material comprises the chlorine-doped nickel oxide as described above.

[0052] In the technical solution of the present invention, chlorine-doped nickel oxide is used as a hole transport material in optoelectronic devices to increase the hole concentration of the hole transport material, improve its conductivity, and improve its hole transport performance. This is extremely critical for optoelectronic devices, especially as a hole transport layer in solar cells. By introducing chlorine-doped nickel oxide as a hole transport material, the present invention not only solves the problems of low conductivity and undesirable energy level matching existing in undoped NiO, but also significantly improves the stability and overall performance of the device. These improvements make the present invention have important application prospects in the field of optoelectronic devices, especially for the pursuit of high efficiency and long life of next-generation photovoltaic technology and display equipment. The present invention provides a reliable and efficient solution.

[0053] In one embodiment, the optoelectronic device includes a perovskite solar cell; the perovskite solar cell includes a substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode layer stacked in sequence, and the hole transport layer includes the chlorine-doped nickel oxide.

[0054] In the technical solution of the present invention, by using chlorine-doped nickel oxide as the material of the hole transport layer, the conductivity and hole transport performance of the hole transport layer of the perovskite solar cell can be improved.

[0055] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0056] Example 1

[0057] This embodiment provides a chlorine-doped nickel oxide, the preparation method of which is as follows:

[0058] Prepare 10mL of nickel nitrate-potassium chloride solution with a nickel nitrate concentration of 1mol / L and a nickel nitrate-potassium chloride molar ratio of 1:0.05. Then, prepare 2mL of 10mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred mixed solution of nickel nitrate and potassium chloride, controlling the dropwise addition rate to ensure a uniform reaction and generate a chlorine-containing nickel hydroxide precipitate. After the dropwise addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge to centrifuge at 5000rpm for 5 minutes to separate the chlorine-containing nickel hydroxide precipitate. Wash the separated precipitate three times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 20°C for 12 hours to obtain chlorine-containing nickel hydroxide powder. Finally, calcine the chlorine-containing nickel hydroxide powder at 270°C for 3 hours to obtain a black solid powder.

[0059] Example 2

[0060] This embodiment provides a chlorine-doped nickel oxide, the preparation method of which is as follows:

[0061] Prepare 10 mL of nickel nitrate-potassium chloride solution with a nickel nitrate concentration of 1 mol / L and a nickel nitrate-potassium chloride molar ratio of 1:0.2. Then, prepare 2 mL of 10 mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred mixed solution of nickel nitrate and potassium chloride, controlling the dropwise addition rate to ensure a uniform reaction and generate a chlorine-containing nickel hydroxide precipitate. After the dropwise addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge to centrifuge at 5000 rpm for 5 minutes to separate the chlorine-containing nickel hydroxide precipitate. Wash the separated precipitate three times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 20°C for 12 hours to obtain chlorine-containing nickel hydroxide powder. Finally, calcine the chlorine-containing nickel hydroxide powder at 270°C for 3 hours to obtain a black solid powder.

[0062] Example 3

[0063] This embodiment provides a chlorine-doped nickel oxide, the preparation method of which is as follows:

[0064] Prepare 10 mL of a nickel nitrate-potassium chloride solution with a nickel nitrate concentration of 1 mol / L and a nickel nitrate-potassium chloride molar ratio of 1:0.25. Then, prepare 2 mL of a 10 mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred mixed solution of nickel nitrate and potassium chloride, controlling the addition rate to ensure a uniform reaction and generate a chlorine-containing nickel hydroxide precipitate. After the addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge at 5000 rpm for 5 minutes to separate the chlorine-containing nickel hydroxide precipitate. Wash the separated precipitate three times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 20°C for 12 hours to obtain a chlorine-containing nickel hydroxide powder. Finally, calcine the chlorine-containing nickel hydroxide powder at 270°C for 3 hours to obtain a black solid powder.

[0065] Example 4

[0066] This embodiment provides a chlorine-doped nickel oxide, the preparation method of which is as follows:

[0067] Prepare 10mL of nickel nitrate-potassium chloride solution with a nickel nitrate concentration of 0.8mol / L and a nickel nitrate-potassium chloride molar ratio of 1:0.2. Then, prepare 2mL of 9mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred mixed solution of nickel nitrate and potassium chloride, controlling the dropwise addition rate to ensure a uniform reaction and generate a chlorine-containing nickel hydroxide precipitate. After the dropwise addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge to centrifuge at 4000rpm for 10 minutes to separate the chlorine-containing nickel hydroxide precipitate. Wash the separated precipitate three times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 20°C for 24 hours to obtain chlorine-containing nickel hydroxide powder. Finally, calcine the chlorine-containing nickel hydroxide powder at 270°C for 4 hours to obtain a black solid powder.

[0068] Example 5

[0069] This embodiment provides a chlorine-doped nickel oxide, the preparation method of which is as follows:

[0070] Prepare 10mL of nickel nitrate-potassium chloride solution with a nickel nitrate concentration of 1.2mol / L and a nickel nitrate-potassium chloride molar ratio of 1:0.2. Then, prepare 2mL of 11mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred mixed solution of nickel nitrate and potassium chloride, controlling the dropwise addition rate to ensure a uniform reaction and generate a chlorine-containing nickel hydroxide precipitate. After the dropwise addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge to centrifuge at 6000rpm for 5 minutes to separate the chlorine-containing nickel hydroxide precipitate. Wash the separated precipitate three times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 15°C for 12 hours to obtain chlorine-containing nickel hydroxide powder. Finally, calcine the chlorine-containing nickel hydroxide powder at 250°C for 3 hours to obtain a black solid powder.

[0071] Example 6

[0072] This embodiment provides a chlorine-doped nickel oxide, the preparation method of which is as follows:

[0073] Prepare 10mL of nickel nitrate-potassium chloride solution with a nickel nitrate concentration of 1.1mol / L and a nickel nitrate-potassium chloride molar ratio of 1:0.25. Then, prepare 2mL of 10mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred mixed solution of nickel nitrate and potassium chloride, controlling the addition rate to ensure a uniform reaction, to produce a chlorine-containing nickel hydroxide precipitate. After the dropwise addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge at 5000rpm for 8 minutes to separate the chlorine-containing nickel hydroxide precipitate. Wash the separated precipitate three times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 25°C for 8 hours to obtain chlorine-containing nickel hydroxide powder. Finally, calcine the chlorine-containing nickel hydroxide powder at 300°C for 2 hours to obtain a black solid powder.

[0074] Example 7

[0075] This embodiment provides a chlorine-doped nickel oxide, the preparation method of which is as follows:

[0076] Prepare 10 mL of nickel nitrate-potassium chloride solution with a nickel nitrate concentration of 1.1 mol / L and a nickel nitrate-potassium chloride molar ratio of 1:0.25. Then, prepare 2 mL of 10 mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred mixed solution of nickel nitrate and potassium chloride, controlling the addition rate to ensure a uniform reaction, to produce a chlorine-containing nickel hydroxide precipitate. After the dropwise addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge at 5000 rpm for 8 minutes to separate the chlorine-containing nickel hydroxide precipitate. Wash the separated precipitate three times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 15°C for 24 hours to obtain a chlorine-containing nickel hydroxide powder. Finally, calcine the chlorine-containing nickel hydroxide powder at 250°C for 4 hours to obtain a black solid powder.

[0077] Comparative Example 1

[0078] This comparative example provides a nickel oxide, the preparation method of which is as follows:

[0079] Prepare 10mL of 1mol / L nickel nitrate solution and 2mL of 10mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred nickel nitrate solution to generate a nickel hydroxide precipitate. After the addition is complete, continue stirring the reaction mixture for 30 minutes to ensure that the reaction is complete. Use a centrifuge to centrifuge at 5000rpm for 5 minutes to separate the generated nickel hydroxide precipitate. Wash the separated precipitate 3 times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 20°C for 12 hours to obtain a dry nickel hydroxide powder. Finally, calcine the dried nickel hydroxide powder at 270°C for 3 hours to obtain a black solid powder.

[0080] Comparative Example 2

[0081] This comparative example provides a nickel oxide, the preparation method of which is as follows:

[0082] Prepare 10mL of nickel nitrate-potassium nitrate solution with a nickel nitrate-potassium nitrate molar ratio of 1:0.2, and prepare 2mL of 10mol / L sodium hydroxide solution. Add the sodium hydroxide solution dropwise to the vigorously stirred nickel nitrate solution to generate a nickel hydroxide precipitate. After the addition is complete, continue stirring the reaction mixture for 30 minutes to ensure complete reaction. Use a centrifuge to centrifuge at 5000rpm for 5 minutes to separate the generated nickel hydroxide precipitate. Wash the separated precipitate 3 times with deionized water to remove impurities. Dry the washed nickel hydroxide precipitate at 20°C for 12 hours to obtain a dry nickel hydroxide powder. Finally, calcine the dried nickel hydroxide powder at 270°C for 3 hours to obtain a black solid powder.

[0083] Performance Testing

[0084] The chlorine-doped nickel oxides of Examples 1 to 3 and the nickel oxide of Comparative Example 1 were dissolved in deionized water at a concentration of 20 mg / mL. After sufficient stirring and standing for 30 minutes, the nickel oxides were dissolved in deionized water at a concentration of 20 mg / mL. Figure 1 As shown, Comparative Example 1, Example 1 and Example 2 can be completely dissolved in deionized water, but Example 3 will precipitate when dissolved in deionized water, indicating that when the concentration of nickel nitrate and potassium chloride reaches 1:0.25, excess chloride ions will cause nickel oxide precipitation.

[0085] The chlorine-doped nickel oxide provided in Example 2 and the nickel oxide of Comparative Example 1 were subjected to X-ray photoelectron spectroscopy (XPS) analysis. The analysis results are as follows: Figure 2 shown.

[0086] according to Figure 2 It can be seen that the chlorine-doped nickel oxide of Example 2 contains obvious Cl element signals (196-200 eV range), indicating that Cl ions are successfully doped into NiO.

[0087] The dissolved nickel oxides from Comparative Example 1, Example 1, and Example 2 were filtered through a 0.22 μm polyethersulfone filter and applied to a 1.68 eV trans-structure (PIN) perovskite solar cell. Example 3, which did not pass through the 0.22 μm polyethersulfone filter, was not filtered and, after mixing, was directly applied to a 1.68 eV trans-structure (PIN) perovskite solar cell. The parameter results for each perovskite solar cell prepared using the above nickel oxide are shown in Table 1.

[0088] Table 1 Parameters of perovskite solar cells

[0089] Conversion efficiency (%) Open circuit voltage (V) <![CDATA[Short-circuit current (mAcm -2 )]]> Fill factor (%) Example 1 19.24 1.223 19.96 78.76 Example 2 19.82 1.223 20.08 80.63 Example 3 14.66 1.134 17.41 74.20 Example 4 16.55 1.201 17.92 76.92 Example 5 15.92 1.185 17.84 75.29 Example 6 14.62 1.162 16.80 74.87 Example 7 14.70 1.166 16.91 74.55 Comparative Example 1 10.17 1.224 11.72 70.88 Comparative Example 2 10.38 1.221 11.82 71.92

[0090] As can be seen from Table 1, the short-circuit current and fill factor of Example 2 are higher than those of Example 1, and both are higher than those of the comparative example. This indicates that, within a certain range, increasing the Cl content helps improve NiO's hole extraction. When the Cl content is increased to reduce NiO solubility, as shown in Example 3, the device efficiency is low. This is because the large NiO particles reduce the uniformity of the film and the hole extraction ability.

[0091] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing chlorine-doped nickel oxide, characterized in that: The following steps are involved: S10. Obtain an aqueous solution of nickel salt and chloride salt, add alkaline solution dropwise, and centrifuge to obtain a coprecipitate; S20. The coprecipitate is washed, dried, and calcined to obtain chlorine-doped nickel oxide; Wherein, the molar ratio of the nickel salt to the chloride salt is (10-20): (1-4).

2. The method for preparing chlorine-doped nickel oxide according to claim 1, wherein: In an aqueous solution of a nickel salt and a chloride salt, the nickel salt is a monobasic nickel salt and the chloride salt is a monobasic chloride salt; The molar ratio of the monobasic nickel salt to the monobasic chloride salt is 20:(1-4).

3. The method for preparing chlorine-doped nickel oxide according to claim 2, wherein: An aqueous solution of a nickel salt and a chloride salt, wherein the nickel salt comprises nickel nitrate and the chloride salt comprises potassium chloride; The molar ratio of nickel nitrate to potassium chloride is 20:(1-4); The molar concentration of nickel nitrate is 0.8 to 1.2 mol / L.

4. The method for preparing chlorine-doped nickel oxide according to claim 1, wherein: The alkaline solution includes a monobasic base, and the molar ratio of the monobasic base to the nickel salt is 2:(3-5).

5. The method for preparing chlorine-doped nickel oxide according to claim 4, wherein: The monobasic alkali is sodium hydroxide, and the concentration of sodium hydroxide in the alkaline solution is 9-11 mol / L.

6. The method for preparing chlorine-doped nickel oxide according to claim 1, wherein: In step S10, the centrifugal speed is 4000-6000 rpm and the centrifugal time is 5-10 min; and / or, In step S20, the drying step adopts vacuum drying, the vacuum drying temperature is 15 to 25° C., the vacuum degree of vacuum drying is between -0.08 and -0.1 MPa, and the vacuum drying time is 8 to 24 hours; and / or, In step S20, the calcination temperature is 250-300°C, and the calcination time is 2-4 hours.

7. A chlorine-doped nickel oxide, characterized in that The chlorine-doped nickel oxide comprises the chlorine-doped nickel oxide prepared by the method for preparing the chlorine-doped nickel oxide according to any one of claims 1 to 6.

8. Application of chlorine-doped nickel oxide in optoelectronic devices, characterized in that: The chlorine-doped nickel oxide includes the chlorine-doped nickel oxide according to claim 7.

9. A photoelectric device, characterized in that: The optoelectronic device comprises a hole transport material, wherein the hole transport material comprises the chlorine-doped nickel oxide according to claim 7 .

10. The optoelectronic device according to claim 9, wherein The optoelectronic device includes a perovskite solar cell; The perovskite solar cell includes a substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode layer stacked in sequence, and the hole transport layer includes the chlorine-doped nickel oxide.

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