Device and method for preparing perovskite layer through low-pressure vapor deposition

Abstract

The invention discloses a device and method for preparing a perovskite layer through low-pressure vapor deposition. The device comprises a feeding transition cabin, organic salt evaporation equipment connected with the feeding transition cabin, a discharging transition cabin connected with the organic salt evaporation equipment and annealing equipment connected with the discharging transition cabin. Wherein a rotating platform, a crystal oscillator probe and a source are arranged in the organic salt evaporation equipment, an inorganic salt carrying table is arranged on the rotating platform, the source is arranged right opposite to the rotating platform, and the crystal oscillator probe is arranged between the rotating platform and the source; a heating plate is arranged on the inorganic salt carrying table and used for heating inorganic salt. According to the invention, the inorganic salt skeleton prepared by the evaporation method is placed in the low-pressure organic salt atmosphere chamber for reaction, so that diffusion and reaction kinetics of organic salt molecules are effectively promoted, complete and uniform conversion of the inorganic salt skeleton is realized, and the perovskite film with high crystal quality and low defect state is obtained. And the method has important research significance for promoting the industrialization process of the perovskite battery.

Description

Technical Field

[0001] This invention relates to a method and apparatus for preparing a perovskite layer, and more particularly to an apparatus and method for preparing a perovskite layer by low-pressure vapor deposition, belonging to the field of perovskite technology. Background Technology

[0002] As a representative of next-generation photovoltaic technology, the fabrication process of high-performance perovskite solar cells has always been a core research focus. Currently, the fabrication of perovskite light-absorbing layers mainly relies on solution methods. However, this method faces inherent challenges in large-scale production, such as solvent toxicity, difficulty in controlling film uniformity, and the inability to precisely control complex components. To overcome these bottlenecks, all-vapor deposition (EVD) has emerged. While it offers advantages such as being solvent-free, having good film uniformity, and being easy to integrate, it typically requires precise control of the simultaneous evaporation of multiple organic and inorganic sources, placing extremely stringent requirements on equipment and control systems, resulting in complex processes and high costs. Based on this, a gas-solid reaction method has been developed, which involves first depositing an inorganic salt framework and then reacting it with organic salt vapor. Although this method simplifies the process, when carried out at atmospheric or high pressure, the diffusion and penetration capacity of organic salt vapor in the inorganic salt framework is insufficient, easily leading to incomplete reactions and a large amount of unconverted inorganic salt remaining at the interface. This results in poor crystal quality and high defect density in the formed perovskite film, ultimately limiting the photoelectric conversion efficiency and stability of the cell. Therefore, there is an urgent need to develop a new method for preparing perovskite layers in the vapor phase that can balance ease of preparation, high-quality thin films, and process controllability. Summary of the Invention

[0003] Purpose of the invention: The first objective of this invention is to provide an apparatus for preparing perovskite layers by low-pressure vapor deposition that can balance ease of preparation, high-quality thin films, and process controllability.

[0004] To achieve the first objective mentioned above, the technical solution of the perovskite layer preparation apparatus provided by the present invention is as follows:

[0005] This invention relates to an apparatus for preparing perovskite layers by low-pressure vapor deposition, comprising a feed transition chamber, an organic salt evaporation device connected to the feed transition chamber, an outlet transition chamber connected to the organic salt evaporation device, and an annealing device connected to the outlet transition chamber; wherein, the organic salt evaporation device is provided with a rotating platform, a crystal oscillator probe, and a source, an inorganic salt stage is provided on the rotating platform, the source is located directly opposite the rotating platform, and the crystal oscillator probe is located between the rotating platform and the source; a heating plate is provided on the inorganic salt stage for heating the inorganic salt.

[0006] The annealing equipment includes an annealing table, a temperature and humidity monitor, and an organic atmosphere monitor.

[0007] To achieve the second objective mentioned above, the technical solution of the perovskite layer preparation apparatus provided by the present invention is as follows:

[0008] The method for preparing a perovskite layer according to the present invention includes the following steps:

[0009] Inorganic salt samples were prepared using a binary co-evaporation method. The inorganic salt stage was preheated to a preset temperature. The organic salt material was placed in the source. The organic salt evaporation equipment was evaporated under vacuum. The source containing the organic salt was heated to a specified temperature. The organic salt could be prepared using a single-source or multi-source co-evaporation method. The inorganic salt sample was transferred from the transition chamber to the inorganic salt stage, which was maintained at a preset temperature. The organic salt evaporation equipment was started, and the organic salt began to deposit on the inorganic salt. After deposition, the product was annealed in an annealing equipment.

[0010] In this process, inorganic salt samples are prepared using PbI2 and CsBr, with an evaporation rate ratio of CsBr:PbI2 = 0.1:1 to 0.2:1, and preferably a thickness of 300 to 500 nm.

[0011] The inorganic salt stage is preheated to 50~150℃.

[0012] The organic salt is selected from formamidine iodide (FAI), methyl iodide (MAI), formamidine hydrochloride (FACl), or methylamine chloride (MACl).

[0013] The organic salt vapor deposition equipment was evacuated to 1e. -6 ~1e -4 Torr.

[0014] The source containing the organic salt is heated to 80-300°C. Preferably, the source is heated to 250-300°C.

[0015] In this process, the inorganic salt sample is moved from the transition chamber to the inorganic salt stage. After the inorganic salt stage heats the inorganic salt sample for 0-2 minutes, the organic salt vapor deposition equipment is started.

[0016] During the annealing process, the ambient temperature is controlled at 20-30℃, the humidity at 30-70%, and the time at 5-15 minutes. The atmosphere can be air, nitrogen, or other organic atmospheres, with an organic atmosphere concentration of 0%-0.15 mg / cm³. 3 Preferably, the atmosphere is selected from one or more of dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), or N-methylpyrrolidone (NMP).

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention provides a process method for preparing perovskite layers by low-pressure vapor deposition. By placing the inorganic salt framework prepared by vapor deposition in a low-pressure organic salt atmosphere chamber for reaction, the diffusion and reaction kinetics of organic salt molecules are effectively promoted. The aim is to achieve complete and uniform transformation of the inorganic salt framework and obtain perovskite thin films with high crystal quality and low defect states. This has important research significance for promoting the industrialization of perovskite solar cells. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the apparatus for preparing perovskite layers by low-pressure vapor deposition according to the present invention.

[0019] Figure 2 The microstructures of the perovskite layers prepared in each example and comparative example are shown below: (a) Comparative Example 1; (b) Example 1; (c) Example 2; (d) Example 3; (e) Example 4; (f) Example 5; (g) Example 6. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0021] like Figure 1 As shown, this embodiment of the invention provides an apparatus for preparing perovskite layers by low-pressure vapor deposition, including a transition chamber 1, a rotating platform 2, a discharge transition chamber 3, a temperature and humidity monitor 4, an organic atmosphere monitor 5, an annealing table 6, a crystal oscillator probe 7, a source 8, an organic salt evaporation device 9, and an annealing device 10. The discharge transition chamber 1 is connected to the organic salt evaporation device 9, the organic salt evaporation device 9 is connected to the discharge transition chamber 3, and the discharge transition chamber 3 is connected to the annealing device 10. The annealing device 10 contains the rotating platform 2, the crystal oscillator probe 7, and the source 8. An inorganic salt stage is mounted on the rotating platform 2, the source 8 is located directly opposite the rotating platform 2, and the crystal oscillator probe 7 is located between the rotating platform 2 and the source 8. A heating plate is mounted on the inorganic salt stage for heating the inorganic salt. The annealing device 10 contains the annealing table 6, the temperature and humidity monitor 4, and the organic atmosphere monitor 5.

[0022] This invention provides a method for preparing a perovskite layer by low-pressure vapor deposition, comprising the following steps:

[0023] S1 Inorganic Salt Evaporation: Inorganic salt samples were prepared using a binary co-evaporation method, utilizing PbI2 and CsBr, with an evaporation rate ratio of CsBr:PbI2 = 0.1:1~0.2:1; and a thickness of 300~500 nm.

[0024] S2 substrate preheating: Preheat the inorganic salt stage to 50~150℃;

[0025] S3 Sample Placement: Place the inorganic salt material (FAI, MAI, FACl, or MACl, etc.) inside the source;

[0026] S4 Vacuuming: Evacuate the chamber to a vacuum level of 1e. -6 ~1e -4 Torr;

[0027] S5 Source Heating: The source containing the organic salt is heated to a specified temperature (80~300℃) at a specified rate (1~5 A / s). The organic salt can be obtained through single-source or multi-source co-distillation (FAI and MAI, FAI and FACl, MAI and MACl, etc.). The evaporation thickness is matched to the inorganic salt thickness, ensuring that the A-site (FAI and MACl) is heated to the specified temperature (80~300℃) at a specified rate (1~5 A / s). + MA + The cations account for 0.7-0.9% of the perovskite content;

[0028] S6 Inorganic Salt Sample Entry: Move the inorganic salt sample from the transition chamber to the inorganic salt stage and preheat for 0~2 min;

[0029] S7 CVD reaction: The substrate baffle is opened, and organic salts begin to deposit;

[0030] S8 reaction complete: substrate baffle closed, sample moved to discharge transition chamber;

[0031] S9 Annealing: Place the sample in an annealing apparatus. The ambient temperature, humidity, and atmosphere of the annealing apparatus are adjustable. Control the ambient temperature at 20~30℃, humidity at 30~70%, and the time at 5~15 minutes. The atmosphere can be air, nitrogen, or other organic atmospheres, with an organic atmosphere concentration of 0%~0.15 mg / cm³. 3 .

[0032] Example 1

[0033] This embodiment provides a method for preparing a perovskite layer by low-pressure vapor deposition, including the following steps:

[0034] S1: Inorganic salt evaporation: Inorganic salt samples were prepared using a binary co-evaporation method, utilizing PbI2 and CsBr, with an evaporation rate ratio of CsBr:PbI2 = 0.1:1; the total film thickness was 400 nm.

[0035] S2 substrate preheating: Inorganic salt stage temperature is 50℃;

[0036] S3 Sample Placement: Place the inorganic salt material FAI inside the source;

[0037] S4 Vacuuming: Evacuate the chamber to a vacuum level of 1e. -4 Torr;

[0038] S5 Source Heating: The source containing the organic salt is heated to a specified temperature of 250℃ at a rate of 1A / s. FAI is selected as the organic salt, and the vapor thickness is 220nm based on the inorganic salt thickness. The resulting composition is Cs. 0.2 FA 0.8 PbI 2.4 Br 0.6 The perovskite layer;

[0039] S6 Inorganic Salt Sample Entry: Move the inorganic salt sample from the transition chamber to the inorganic salt stage and preheat for 2 minutes;

[0040] S7CVD reaction: The substrate baffle is opened, and organic salts begin to deposit;

[0041] S8 reaction complete: substrate baffle closed, sample moved to discharge transition chamber;

[0042] S9 Annealing: Place the sample in the annealing apparatus. The ambient temperature, humidity and atmosphere of the annealing apparatus are adjustable. Control the ambient temperature at 25℃, humidity at 50%, annealing time at 15min, and the atmosphere at air.

[0043] Example 2

[0044] Compared with Example 1, Example 2 only adjusts the inorganic salt stage temperature during the S2 substrate preheating process to 100°C.

[0045] Example 3

[0046] Compared with Example 1, Example 3 only adjusts the inorganic salt stage temperature during the S2 substrate preheating process to 150°C.

[0047] Example 4

[0048] Compared with Example 2, Example 4 only changed the inorganic salt evaporation rate in the inorganic salt process to CsBr:PbI2=0.2:1.

[0049] Example 5

[0050] Compared with Example 2, Example 5 only changed the organic salt from simple FAI to FAI+FACl, and mixed them at a rate ratio of FAI:FACl=4:1. The total thickness of the organic salt was 220nm.

[0051] Example 6

[0052] Compared with Example 5, Example 6 only changed the annealing atmosphere from air to DMSO, with a concentration of 0.1 mg / cm³. 3 atmosphere.

[0053] Comparative Example

[0054] The difference between this comparative example and Example 1 is that the inorganic salt stage does not have a heating function and its temperature is room temperature. Specifically, the steps for preparing the perovskite layer in this comparative example are as follows:

[0055] S1: Inorganic salt evaporation: Inorganic salt samples were prepared using a binary co-evaporation method, utilizing PbI2 and CsBr, with an evaporation rate ratio of CsBr:PbI2 = 0.1:1; the total film thickness was 400 nm.

[0056] S2 substrate preheating: Inorganic salt stage temperature is 25℃;

[0057] S3 Sample Placement: Inorganic salt material FAI is placed in different sources;

[0058] S4 Vacuuming: Evacuate the chamber to a vacuum level of 1e. -4 Torr;

[0059] S5 Source Heating: The source containing the organic salt is heated to a specified temperature of 250℃ at a rate of 1A / s. FAI is selected as the organic salt, and the vapor thickness is based on the inorganic salt thickness of 220nm. The resulting composition is Cs. 0.2 FA 0.8 PbI 2.4 Br 0.6 The perovskite layer;

[0060] S6 Inorganic Salt Sample Entry: Move the inorganic salt sample from the transition chamber to the inorganic salt stage and preheat for 2 minutes;

[0061] S7CVD reaction: The substrate baffle is opened, and organic salts begin to deposit;

[0062] S8 reaction complete: substrate baffle closed, sample moved to discharge transition chamber;

[0063] S9 Annealing: Place the sample in the annealing apparatus. The ambient temperature, humidity and atmosphere of the annealing apparatus are adjustable. The ambient temperature is controlled at 25℃, the humidity at 50%, and the atmosphere is air.

[0064] like Figure 2 As shown in the comparative examples and Examples 1 to 3, it can be seen that as the process reaction temperature increases, the reaction becomes more complete and the grain size gradually increases. However, when the process reaction temperature is 150°C, the grains become fine and fragmented. This is because the reaction temperature is too high, causing an excessive amount of FAI to enter the reaction.

[0065] Compared with Example 2, Example 4 increased the proportion of CsBr in the inorganic salt. This is because the lattice distortion (thermodynamically unfavorable) caused by the Cs⁺ ion radius and the high nucleation density and inhibition of grain boundary migration during crystallization result in smaller grains.

[0066] In Example 5, compared to Example 2, the organic salt was changed from FAI to FAI+FACl. Cl promoted the diffusion of the organic salt in the inorganic salt, making the perovskite reaction more complete and the grains grow, but certain porosity defects existed.

[0067] In Example 6, compared to Example 5, a certain amount of DMSO was added to the annealing atmosphere, which caused the grains to regrow and reduced defects such as pores.

[0068] The conversion efficiency of the perovskite solar cells prepared using this method is as follows:

[0069] Table 1 Electrical performance data of different samples

[0070] Voc(V) <![CDATA[Jsc(mA / cm 2 )]]> FF (%) PCE (%) Comparative Example 1.692322 22.746832 64.700215 24.90633 Example 1 1.717384 21.910907 67.142355 25.265289 Example 2 1.789393 21.541256 70.862 27.314307 Example 3 1.76946 22.253604 66.508111 26.188804 Example 4 1.778213 22.720691 67.581071 27.304253 Example 5 1.814584 22.119838 72.603681 29.141888 Example 6 1.862115 21.77515 74.597056 30.247487

[0071] As shown in Table 1, the electrical properties of the samples prepared in Examples 1-6 were significantly improved compared to the comparative examples. This indicates that continuous heating of the inorganic salts during the reaction in a low-pressure organic salt atmosphere chamber can significantly improve the crystallinity of the final film.

Claims

1. An apparatus for preparing perovskite layers by low-pressure vapor deposition, characterized in that, It includes a feeding transition chamber, an organic salt vapor deposition equipment connected to the feeding transition chamber, an unloading transition chamber connected to the organic salt vapor deposition equipment, and an annealing equipment connected to the unloading transition chamber; wherein, the organic salt vapor deposition equipment is equipped with a rotating platform, a crystal oscillator probe and a source, an inorganic salt stage is provided on the rotating platform, the source is located directly opposite the rotating platform, and the crystal oscillator probe is located between the rotating platform and the source; a heating plate is provided on the inorganic salt stage for heating the inorganic salt.

2. The apparatus for preparing perovskite layers by low-pressure vapor deposition according to claim 1, characterized in that, The annealing equipment is equipped with an annealing table, a temperature and humidity monitor, and an organic atmosphere monitor.

3. A method for preparing a perovskite layer using the apparatus according to any one of claims 1-2, characterized in that, Includes the following steps: Inorganic salt samples were prepared using a binary co-evaporation method. The inorganic salt stage was preheated to a preset temperature. The organic salt material was placed in the source. The organic salt evaporation equipment was evacuated. The source containing the organic salt was heated to a specified temperature. The organic salt could be prepared using a single-source or multi-source co-evaporation method. The inorganic salt sample was transferred from the transition chamber to the inorganic salt stage, which was maintained at a preset temperature. The organic salt evaporation equipment was started, and the organic salt began to deposit on the inorganic salt. After deposition, the product was annealed in an annealing equipment.

4. The method for preparing a perovskite layer according to claim 3, characterized in that, Inorganic salt samples were prepared using PbI2 and CsBr with an evaporation rate ratio of CsBr:PbI2 = 0.1:1 to 0.2:

1.

5. The method for preparing a perovskite layer according to claim 3, characterized in that, The inorganic salt stage is preheated to 50~150℃.

6. The method for preparing a perovskite layer according to claim 3, characterized in that, The organic salt is selected from FAI, MAI, FACl or MACl.

7. The method for preparing a perovskite layer according to claim 3, characterized in that, The organic salt vapor deposition equipment is evacuated to 1e. -6 ~1e -4 Torr.

8. The method for preparing a perovskite layer according to claim 3, characterized in that, Heat the source containing the organic salt to 80~300℃.

9. The method for preparing a perovskite layer according to claim 3, characterized in that, The inorganic salt sample is moved from the transition chamber to the inorganic salt stage. After the inorganic salt stage heats the inorganic salt sample for 0-2 minutes, the organic salt vapor deposition equipment is started.

10. The method for preparing a perovskite layer according to claim 3, characterized in that, During the annealing process, the atmosphere can be air, nitrogen, or an organic atmosphere.

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