Multi-cavity vacuum flash evaporation system for preparing perovskite film

Abstract

The invention provides a multi-cavity vacuum flash evaporation system for preparing a perovskite thin film. The multi-cavity vacuum flash evaporation system comprises an internal vacuum cavity, a vacuum pipeline, an external vacuum cavity, a large-pumping-amount mechanical pump, a molecular pump, a copper pipe cold trap and an air pumping pipeline. The built-in vacuum cavity is connected with the external vacuum cavity through a vacuum pipeline, and the vacuum pipeline is controlled to be opened and closed through an electromagnetic valve; the external vacuum cavity is connected with a copper pipe cold trap through an air exhaust pipeline, and the copper pipe cold trap is connected with a large-pumping-amount mechanical pump and a molecular pump through an auxiliary pipeline; a plurality of external vacuum cavities can be designed, a graded adjustment vacuum baffle is arranged in each external vacuum cavity, and the positions of the graded adjustment vacuum baffles are controlled through vertical movement, so that the volume required by actual vacuumizing of the external vacuum cavities is adjusted, and the volume ratio of the internal vacuum cavity to the external vacuum cavities is improved; the vacuumizing speed is increased, the cavity accurately reaches the preset vacuum rate, and the vacuum degree of the cavity is regulated and controlled.

Description

Technical Field

[0001] The invention belongs to the technical field of perovskite photovoltaic cells, and in particular relates to a multi-cavity vacuum flash evaporation system for preparing perovskite films. Background Art

[0002] Perovskite solar cells have become one of the frontiers of new energy research due to their low cost, high efficiency, diverse application scenarios, and good weak light response. Perovskite solar cells use perovskite-type organic metal halide semiconductors as light-absorbing materials, which are applied in the light-absorbing layer of solar cells in the form of thin films. The uniformity and density of perovskite thin films are key factors affecting the overall performance of the device.

[0003] Flash evaporation is a vacuum-based evaporation method, which is particularly suitable for preparing perovskite thin films for solar cells. Growth pressure is a key parameter for perovskite film growth. The rate, stability and accuracy of chamber vacuum pumping are closely related to the quality of perovskite film formation. A commonly used two-stage rotary vane vacuum pump is directly connected to a 1000cm 3 It takes a long time, 10 to 15 seconds, to evacuate the vacuum chamber from 1 atmosphere to 0.01 MPa. In addition, due to instrument delays and non-transient gas changes, the vacuum degree is difficult to control, which requires further improvement. Summary of the invention

[0004] The present invention provides a multi-cavity vacuum flash evaporation system for preparing perovskite thin films, which solves the problems of slow vacuum pumping rate of the existing flash evaporation system, delay in vacuum degree monitoring caused by non-transient pressure change in the vacuum chamber, and inability of the vacuum chamber to accurately reach the final preset vacuum degree. The vacuum pumping speed of the multi-cavity vacuum flash evaporation system can be increased from 1L / s to 10-15L / s, and the preset vacuum degree can be stably reached to a minimum of 10 -6 Pa, so as to achieve fast, accurate and stable controllable effect on the flash vacuum chamber.

[0005] To solve the above problems, the technical solution provided by the present invention is as follows:

[0006] An embodiment of the present invention provides a multi-cavity vacuum flash evaporation system for preparing a perovskite thin film, comprising a built-in vacuum chamber (1), a large-volume mechanical pump (3), a molecular pump (4), a copper tube cold trap (5) and an exhaust pipe (6); the exhaust pipe (6) is connected to a first branch pipe (6-1), a second branch pipe (6-2) and a third branch pipe (6-3); the preset apertures and preset lengths of the first branch pipe (6-1), the second branch pipe (6-2) and the third branch pipe (6-3) are used to affect the vacuum pumping rate;

[0007] The built-in vacuum chamber (1) is connected to a first external vacuum chamber (2-1) via a first vacuum pipe (7-1), and the first external vacuum chamber (2-1) is connected to the first branch pipe (6-1); the built-in vacuum chamber (1) is connected to a second external vacuum chamber (2-2) via a second vacuum pipe (7-2), and the second external vacuum chamber (2-2) is connected to the second branch pipe (6-2); the built-in vacuum chamber (1) is connected to a third external vacuum chamber (2-3) via a third vacuum pipe (7-3), and the third external vacuum chamber (2-3) is connected to the third branch pipe (6-3);

[0008] The end of the exhaust pipe (6) is connected to the copper tube cold trap (5), and the copper tube cold trap (5) is respectively connected to a molecular pump (4) and a large-volume mechanical pump (3) through a fourth branch pipe and a fifth branch pipe of the first auxiliary pipe (13), and the molecular pump (4) and the large-volume mechanical pump (3) are connected through a second auxiliary pipe (14).

[0009] According to an optional embodiment of the present invention, the first external vacuum chamber (2-1), the second external vacuum chamber (2-2) and the third external vacuum chamber (2-3) are all detachable large-capacity external vacuum chambers; wherein the volume ratio of the internal vacuum chamber (1) to the volume of the detachable large-capacity external vacuum chamber is 1:100.

[0010] According to an optional embodiment of the present invention, a first graded adjustable vacuum baffle (8-1) is arranged in the first external vacuum chamber (2-1), a second graded adjustable vacuum baffle (8-2) is arranged in the second external vacuum chamber (2-2), and a third graded adjustable vacuum baffle (8-3) is arranged in the third external vacuum chamber (2-3), and the position of the graded adjustable vacuum baffle is controlled by moving up and down, thereby adjusting the actual volume required for vacuuming the external vacuum chamber.

[0011] According to an optional embodiment of the present invention, the interface between the built-in vacuum chamber (1) and the first vacuum pipe (7-1) is sealed using a first sealing gasket (10-1) and a first sealing ring (11-1).

[0012] According to an optional embodiment of the present invention, the interface between the first vacuum pipe (7-1) and the first external vacuum chamber (2-1) is sealed by a second sealing gasket (10-2) and a second sealing ring (11-2); the interface between the second vacuum pipe (7-2) and the second external vacuum chamber (2-2) is sealed by a third sealing gasket (10-3) and a third sealing ring (11-3); and the interface between the third vacuum pipe (7-3) and the third external vacuum chamber (2-3) is sealed by a fourth sealing gasket (10-4) and a second sealing ring (11-4).

[0013] According to an optional embodiment of the present invention, a first solenoid valve (9-1) is provided at the connection between the second vacuum pipe (7-2) and the first vacuum pipe (7-1), and a second solenoid valve (9-2) is provided at the connection between the third vacuum pipe (7-3) and the second vacuum pipe (7-2).

[0014] According to an optional embodiment of the present invention, a third solenoid valve (9-3), a fourth solenoid valve (9-4) and a fifth solenoid valve (9-5) are respectively provided on the first branch pipe (6-1), the second branch pipe (6-2) and the third branch pipe (6-3).

[0015] According to an optional embodiment of the present invention, the fourth branch pipe and the fifth branch pipe of the first auxiliary pipe (13) are respectively provided with a sixth solenoid valve (9-6) and a seventh solenoid valve (9-7), and the second auxiliary pipe (14) is provided with an eighth solenoid valve (9-8).

[0016] Compared with the prior art, the embodiments of the present invention provide a multi-cavity vacuum flash evaporation system for preparing perovskite thin films, which has the following beneficial effects: the present invention solves the shortcomings of traditional flash evaporation vacuum system technology, such as slow vacuum pumping rate, vacuum degree monitoring delay caused by non-transient air pressure changes in the vacuum chamber, and the inability of the vacuum chamber to accurately reach the final preset vacuum degree. The present invention adopts the design of a multi-cavity vacuum flash evaporation system to effectively achieve fast, accurate and stable controllable effects on the flash evaporation vacuum chamber, thereby improving the quality of perovskite film formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 Schematic diagram of a multi-chamber vacuum flash evaporation system for preparing perovskite thin films provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0020] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. It should also be noted that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection: it can be directly connected, it can also be indirectly connected through an intermediate medium, and it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. The following descriptions of the embodiments are with reference to the attached drawings to illustrate specific embodiments in which the present invention can be implemented. The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only used to refer to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, but are not used to limit the present invention. In the drawings, units with similar structures are represented by the same reference numerals.

[0021] The embodiment of the present invention provides a multi-cavity vacuum flash evaporation system for preparing perovskite thin films, aiming to improve the existing vacuum flash evaporation equipment, such as slow vacuuming rate and difficult to control the vacuum degree of the cavity caused by the vacuum pump directly connected to the cavity. The present invention can obtain high-quality perovskite thin films with large grain size, good crystallinity, uniform film formation and compactness by designing, optimizing and improving the vacuum flash evaporation system, thereby significantly improving the application potential of perovskite solar cells in large-area preparation processes, which is crucial to improving the photoelectric conversion efficiency, stability and life of solar cells, and paving the way for future commercial applications.

[0022] like Figure 1 As shown, a multi-cavity vacuum flash evaporation system for preparing perovskite thin films includes a built-in vacuum chamber 1, a vacuum pipeline, an external vacuum chamber, a large-volume mechanical pump 3, a molecular pump 4, a copper tube cold trap 5, and an exhaust pipeline 6. The exhaust pipeline 6 is connected to a first branch pipeline 6-1, a second branch pipeline 6-2, and a third branch pipeline 6-3. The preset apertures and preset lengths of the first branch pipeline 6-1, the second branch pipeline 6-2, and the third branch pipeline 6-3 are used to affect the vacuum pumping rate.

[0023] The built-in vacuum chamber 1 is connected to an external vacuum chamber through a vacuum pipe, and the vacuum pipe switch is controlled by a solenoid valve. The present invention adopts the design of multiple external vacuum chambers to effectively achieve the fast, accurate and stable controllable effect of the flash vacuum chamber, thereby improving the quality of perovskite film formation. Specifically, the built-in vacuum chamber 1 is connected to the first external vacuum chamber 2-1 through the first vacuum pipe 7-1, and the first external vacuum chamber 2-1 is connected to the first branch pipe 6-1. The built-in vacuum chamber 1 is connected to the second external vacuum chamber 2-2 through the second vacuum pipe 7-2, and the second external vacuum chamber 2-2 is connected to the second branch pipe 6-2. The built-in vacuum chamber 1 is connected to the third external vacuum chamber 2-3 through the third vacuum pipe 7-3, and the third external vacuum chamber 2-3 is connected to the third branch pipe 6-3.

[0024] The end of the exhaust pipe 6 is connected to a copper tube cold trap 5, which is respectively connected to a molecular pump 4 and a large-volume mechanical pump 3 through the fourth branch pipe and the fifth branch pipe of the first auxiliary pipe 13, and the molecular pump 4 and the large-volume mechanical pump 3 are connected through a second auxiliary pipe 14.

[0025] The first external vacuum chamber 2-1, the second external vacuum chamber 2-2 and the third external vacuum chamber 2-3 are all removable large-capacity external vacuum chambers. The cavity of the removable large-capacity external vacuum chamber is preferably designed with two or more cavities, and is made of lightweight materials that can be freely removable, so as to regulate the vacuum degree in the built-in vacuum chamber 1 to increase or decrease steadily step by step. Among them, the volume ratio of the built-in vacuum chamber 1 to the volume of the removable large-capacity external vacuum chamber is 1:100. The built-in vacuum chamber 1 of this embodiment is a removable large-capacity external vacuum chamber connected by a vacuum pipe. With the design of multiple external vacuum chambers, at the moment the solenoid valve is opened, after the gas connected to the cavity reaches equilibrium, the built-in vacuum chamber 1 can instantly reach the preset vacuum degree. The aperture of the removable large-capacity external vacuum chamber (the first vacuum pipe 7-1, the second vacuum pipe 7-2 and the third vacuum pipe 7-3) should be large and the length should be short. In addition, each removable large-capacity external vacuum chamber always maintains 1.3×10 -1 ~1.3×10 -6 The high vacuum state of Pa is achieved and the sealing is good, so that the built-in vacuum chamber 1 can quickly reach the preset vacuum degree. Compared with the traditional vacuum pumping method, the extraction rate of the present invention can be increased by 70% to 90%.

[0026] The first external vacuum chamber 2-1 is provided with a first graded adjustment vacuum baffle 8-1, the second external vacuum chamber 2-2 is provided with a second graded adjustment vacuum baffle 8-2, and the third external vacuum chamber 2-3 is provided with a third graded adjustment vacuum baffle 8-3. The external vacuum chamber of the present invention is provided with a graded adjustment vacuum baffle inside, and the position of the graded adjustment vacuum baffle is controlled by moving up and down, thereby adjusting the actual volume required for vacuuming the external vacuum chamber, and adjusting the volume ratio of the built-in vacuum chamber 1 and the external vacuum chamber to accurately control the chamber to reach a preset vacuum degree, thereby achieving an increase in the vacuuming speed and accurately reaching the preset vacuum rate and the vacuum degree of the chamber. The chamber of the external vacuum chamber can be designed with one, two or more chambers according to demand, and can be freely disassembled using lightweight materials, so as to regulate the vacuum degree in the built-in vacuum chamber 1 to increase or decrease steadily step by step.

[0027] The sealing device includes a sealing ring and a sealing gasket, which is used for the connection between the inner and outer vacuum chambers of the vacuum pipe to maintain the vacuum environment of the vacuum chamber. The present invention is provided with a sealing gasket and a sealing ring at the interface between the vacuum pipe and the built-in vacuum chamber and the external vacuum chamber to prevent the wear of the interface after the system is normally operated or the vacuum chamber is disassembled, resulting in a decrease in the vacuum pumping capacity, so as to maintain the vacuum environment of the vacuum chamber. Specifically, the interface between the built-in vacuum chamber 1 and the first vacuum pipe 7-1 is sealed with a first sealing gasket 10-1 and a first sealing ring 11-1. The interface between the first vacuum pipe 7-1 and the first external vacuum chamber 2-1 is sealed with a second sealing gasket 10-2 and a second sealing ring 11-2. The interface between the second vacuum pipe 7-2 and the second external vacuum chamber 2-2 is sealed with a third sealing gasket 10-3 and a third sealing ring 11-3. The interface between the third vacuum pipe 7-3 and the third external vacuum chamber 2-3 is sealed with a fourth sealing gasket 10-4 and a second sealing ring 11-4.

[0028] A first solenoid valve 9-1 is provided at the connection between the second vacuum pipe 7-2 and the first vacuum pipe 7-1, and a second solenoid valve 9-2 is provided at the connection between the third vacuum pipe 7-3 and the second vacuum pipe 7-2. A third solenoid valve 9-3, a fourth solenoid valve 9-4 and a fifth solenoid valve 9-5 are provided on the first branch pipe 6-1, the second branch pipe 6-2 and the third branch pipe 6-3, respectively. A sixth solenoid valve 9-6 and a seventh solenoid valve 9-7 are provided on the fourth branch pipe and the fifth branch pipe of the first auxiliary pipe 13, respectively, and an eighth solenoid valve 9-8 is provided on the second auxiliary pipe 14. The above-mentioned solenoid valves are used to open or close the corresponding pipes.

[0029] Furthermore, the volume of the built-in vacuum chamber is much smaller than that of the removable large-capacity external vacuum chamber, with a volume ratio of 1 to 100. 3It takes 1 to 1.5 seconds for the vacuum chamber to be evacuated from 1 atmosphere to 0.01 MPa, which greatly improves the speed at which the built-in vacuum chamber reaches the preset vacuum degree. Furthermore, the vacuum pipe connecting the built-in vacuum chamber and the external vacuum chamber should have a large aperture and a short length to quickly enable the built-in vacuum chamber to reach the preset vacuum degree. Furthermore, the external vacuum chamber can be designed with two or more cavities, and can be freely disassembled using lightweight materials to control the vacuum degree in the cavity to increase or decrease steadily step by step, and to facilitate the replacement and cleaning of the cavity. Furthermore, the external vacuum chamber always maintains 1.3×10 -1 ~1.3×10 -6 The high vacuum state of Pa is achieved so that when the electromagnetic valve between the external chamber and the internal chamber is opened, the internal chamber and the vacuum system can quickly reach the required high vacuum state. Furthermore, the sealing ring and the sealing gasket are used to seal the connection between the vacuum pipe and the connection between the inner and outer vacuum chambers to maintain the vacuum environment of the vacuum chamber.

[0030] The multi-chamber vacuum flash evaporation system for preparing perovskite thin films provided by the present invention has the following beneficial effects: it effectively solves several key problems of traditional flash evaporation vacuum system technology: slow vacuum pumping rate, vacuum degree monitoring delay caused by non-transient pressure changes in the vacuum chamber, and the vacuum chamber cannot accurately reach the final preset vacuum degree. This invention achieves fast, accurate and stable controllable effects on the flash evaporation vacuum chamber, significantly improving the quality of perovskite film formation. Specifically, fast refers to fast vacuum pumping rate, accurate refers to accurately reaching the preset vacuum degree, and stable refers to the vacuum chamber can stably evacuate to reach the preset vacuum degree.

[0031] In summary, although the present invention has been disclosed as above in terms of preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films, characterized in that: The invention comprises a built-in vacuum chamber (1), a large-volume mechanical pump (3), a molecular pump (4), a copper tube cold trap (5) and an exhaust pipe (6); the exhaust pipe (6) is connected to a first branch pipe (6-1), a second branch pipe (6-2) and a third branch pipe (6-3); the preset apertures and preset lengths of the first branch pipe (6-1), the second branch pipe (6-2) and the third branch pipe (6-3) are used to influence the vacuum pumping rate; The built-in vacuum chamber (1) is connected to a first external vacuum chamber (2-1) via a first vacuum pipe (7-1), and the first external vacuum chamber (2-1) is connected to the first branch pipe (6-1); the built-in vacuum chamber (1) is connected to a second external vacuum chamber (2-2) via a second vacuum pipe (7-2), and the second external vacuum chamber (2-2) is connected to the second branch pipe (6-2); the built-in vacuum chamber (1) is connected to a third external vacuum chamber (2-3) via a third vacuum pipe (7-3), and the third external vacuum chamber (2-3) is connected to the third branch pipe (6-3); The end of the exhaust pipe (6) is connected to the copper tube cold trap (5), and the copper tube cold trap (5) is respectively connected to a molecular pump (4) and a large-volume mechanical pump (3) through a fourth branch pipe and a fifth branch pipe of the first auxiliary pipe (13), and the molecular pump (4) and the large-volume mechanical pump (3) are connected through a second auxiliary pipe (14).

2. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films according to claim 1, characterized in that: The first external vacuum chamber (2-1), the second external vacuum chamber (2-2) and the third external vacuum chamber (2-3) are all detachable large-capacity external vacuum chambers; wherein the volume ratio of the internal vacuum chamber (1) to the volume of the detachable large-capacity external vacuum chamber is 1:

100.

3. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films according to claim 2, characterized in that: A first graded adjustable vacuum baffle (8-1) is arranged in the first external vacuum chamber (2-1), a second graded adjustable vacuum baffle (8-2) is arranged in the second external vacuum chamber (2-2), and a third graded adjustable vacuum baffle (8-3) is arranged in the third external vacuum chamber (2-3), and the position of the graded adjustable vacuum baffle is controlled by moving up and down, thereby adjusting the actual volume required for vacuuming the external vacuum chamber.

4. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films according to claim 1, characterized in that: The interface between the built-in vacuum chamber (1) and the first vacuum pipe (7-1) is sealed using a first sealing gasket (10-1) and a first sealing ring (11-1).

5. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films according to claim 4, characterized in that: The interface between the first vacuum pipe (7-1) and the first external vacuum chamber (2-1) is sealed by a second sealing gasket (10-2) and a second sealing ring (11-2); the interface between the second vacuum pipe (7-2) and the second external vacuum chamber (2-2) is sealed by a third sealing gasket (10-3) and a third sealing ring (11-3); and the interface between the third vacuum pipe (7-3) and the third external vacuum chamber (2-3) is sealed by a fourth sealing gasket (10-4) and a second sealing ring (11-4).

6. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films according to claim 1, characterized in that: A first solenoid valve (9-1) is provided at the connection between the second vacuum pipeline (7-2) and the first vacuum pipeline (7-1), and a second solenoid valve (9-2) is provided at the connection between the third vacuum pipeline (7-3) and the second vacuum pipeline (7-2).

7. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films according to claim 6, characterized in that: The first branch pipeline (6-1), the second branch pipeline (6-2) and the third branch pipeline (6-3) are respectively provided with a third solenoid valve (9-3), a fourth solenoid valve (9-4) and a fifth solenoid valve (9-5).

8. A multi-chamber vacuum flash evaporation system for preparing perovskite thin films according to claim 7, characterized in that: The fourth branch pipeline and the fifth branch pipeline of the first auxiliary pipeline (13) are respectively provided with a sixth solenoid valve (9-6) and a seventh solenoid valve (9-7), and the second auxiliary pipeline (14) is provided with an eighth solenoid valve (9-8).

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