Drying and annealing device for preparing thermal cycle perovskite thin film and preparation method

Abstract

The invention discloses a drying and annealing device for preparing a thermal cycle perovskite thin film and a preparation method, and relates to the technical field of annealing processes. A plurality of annealing chambers are arranged in the front of the interior of a box body, windows are arranged in front of the annealing chambers, front cover plates are arranged in front of the annealing chambers, air inlet channels and air outlet channels are arranged at the top end and the middle position of the rear of the interior of the box body respectively, and air inlet holes and air outlet holes are formed in the annealing chambers respectively. Inert gas is introduced and discharged by being connected with external gas heating circulation equipment, a containing cavity is formed in the bottom end of the rear portion in the box body and used for storing an organic solvent volatilization box, a window is formed in the rear portion of the containing cavity, a rear cover plate is arranged, and solvent atmosphere channels are formed in the containing cavity and the annealing cavities respectively. The perovskite thin film is prepared by adopting a top-to-bottom thermal cycle annealing method and utilizing a high-temperature inert gas drying mode, so that the perovskite film forming quality can be improved, and a plurality of perovskite thin film samples in one batch can be annealed at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of annealing processes, and in particular to a drying annealing device and a preparation method for a thermal cycle perovskite film. Background Art

[0002] Perovskites are becoming increasingly popular in solar cells, light-emitting diodes (LEDs), lasers, and photodetectors due to their unique optical and electronic properties. In addition, the ease of synthesis, low production cost, and solution processability also make this material highly sought after in the manufacture of commercial optoelectronic devices. Since the demonstration of the first room-temperature perovskite LED in 2014, significant progress has been made in this field.

[0003] Annealing is essential in the preparation process of perovskite films. The control of the annealing process has an important influence on the crystallization quality, crystal grain size and defect state density of the perovskite film. A good annealing method is crucial to improving the quality of perovskite film formation.

[0004] However, the current annealing method generally places the entire substrate directly on a hot plate for annealing. This traditional annealing method will cause a temperature gradient from bottom to top in the vertical direction of the perovskite film. This temperature distribution may cause the perovskite film to start the crystallization process from both the top and bottom directions at the same time, thereby increasing the number of grain boundaries and defects. What is particularly critical is that the difference in thermal expansion coefficients between the perovskite film and its substrate often induces tensile stress at the interface between them, which will have an adverse effect on the efficiency and stability of the device. Summary of the invention

[0005] In order to overcome the shortcomings of the background technology, the present invention provides a drying annealing device and a preparation method for thermal cycle perovskite film preparation, which adopts a top-down thermal cycle annealing method and utilizes high-temperature inert gas drying to prepare the perovskite film, which can improve the quality of perovskite film formation and can simultaneously perform annealing tasks on a batch of multiple perovskite film samples.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A drying annealing device for preparing a thermal cycle perovskite film, comprising a box, a front cover, an air inlet channel, an exhaust channel, a rear cover and an organic solvent volatilization box, wherein a plurality of mutually independent annealing chambers are arranged horizontally in the front of the box, windows are provided in front of the plurality of annealing chambers, a substrate is placed on the table in each annealing chamber, the front cover is respectively provided on the window of each annealing chamber, an air inlet channel and an exhaust channel are respectively provided horizontally at the top and middle position of the rear of the box, and one end of each of the air inlet channel and the exhaust channel is connected to the side of the box. The air inlet channel and the corresponding positions of the rear wall of each annealing chamber are respectively provided with air inlet holes, and the exhaust channel and the corresponding positions of the rear wall of each annealing chamber are respectively provided with exhaust holes. The air inlet channel and the exhaust channel are connected to the external gas heating circulation equipment to realize the introduction and discharge of inert gas. A placement cavity is horizontally arranged at the bottom end of the rear of the box body and an organic solvent volatilization box is stored. The organic solvent volatilization box stores volatile organic solvents. A window is arranged at the rear of the placement cavity. The window of the placement cavity is provided with the rear cover plate. Solvent atmosphere channels are respectively arranged at the corresponding positions of the placement cavity and the rear wall of each annealing chamber.

[0008] Furthermore, an intake air temperature detector is installed on the rear wall of each annealing chamber in the box body near the air inlet hole.

[0009] Furthermore, a table temperature detector is installed at the bottom of each annealing chamber in the box.

[0010] Furthermore, the front cover plate and the rear cover plate are pull-out cover plates.

[0011] Furthermore, the substrate is a rigid glass substrate or a PET flexible substrate or a smooth glass slide covered with a patterned ITO electrode.

[0012] A method for preparing a thermal cycle perovskite film comprises the following steps:

[0013] Step 1: Prepare perovskite precursor solution;

[0014] Step 2: Prepare a perovskite film using a perovskite precursor solution, including:

[0015] S2.1. Clean the substrate using deionized water, anhydrous ethanol, acetone, isopropanol and anhydrous ethanol in sequence;

[0016] S2.2. Use nitrogen to blow dry the substrate, irradiate with plasma for 10 to 15 minutes, and then transfer it into a glove box filled with nitrogen;

[0017] S2.3, taking the perovskite precursor solution and dropping it on the surface of the substrate;

[0018] S2.4, preparing a perovskite film by spin coating;

[0019] Step 3: Performing thermal cycle drying annealing on the prepared perovskite film, including:

[0020] S3.1. Store the volatile organic solvent in the organic solvent volatilization box and put it into the placement cavity, completely seal the front cover plate and the rear cover plate, connect the external gas heating circulation equipment through the air inlet channel and the exhaust channel to supply high-temperature inert gas to each annealing chamber in the box, and the high-temperature inert gas refers to the temperature controlled at 50-120°C;

[0021] S3.2, when the table temperature in each annealing chamber reaches 40-100°C, open the corresponding front cover plate, place the substrate carrying the perovskite film on the table in the annealing chamber, and close the front cover plate again;

[0022] S3.3. During the annealing process of the perovskite film, the volatile gas generated by the volatilized organic solvent is transported to each annealing chamber through the solvent atmosphere channel. The high-temperature inert gas circulates from top to bottom to dry the perovskite film until the annealing of the perovskite film is completed. The external gas heating circulation equipment is turned off and the substrate carrying the perovskite film is taken out.

[0023] Furthermore, the perovskite precursor solution in step 1 is prepared by dissolving 44.7 mg of CsBr, 27.8 mg of PbCl2, 36.7 mg of PbBr2 and 28.3 mg of PEABr in 1 mL of DMSO solvent.

[0024] Furthermore, the spin coating conditions in step 2 are a rotation speed of 3000 to 6000 rpm and a time of 25 to 45 s.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention abandons the traditional bottom-up annealing process, and instead adopts a top-down thermal cycle annealing method, and utilizes high-temperature inert gas drying to prepare the perovskite film, which can improve the perovskite film quality, optimize the crystallization quality, and help control the nucleation behavior of the perovskite film, significantly improving the luminous efficiency of the perovskite LED device, and through the design of the drying annealing device, it is possible to perform annealing tasks on a batch of multiple perovskite film samples at the same time without affecting each other, thereby improving the annealing operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the drying and annealing device of the present invention;

[0027] Figure 2 yes Figure 1 A rear view of

[0028] Figure 3 It is a schematic diagram of the top-down annealing principle of the preparation method of the present invention;

[0029] Figure 4 It is a comparison diagram of the in-plane tensile strain of the perovskite film prepared by conventional annealing and the method of the present invention;

[0030] Figure 5 It is the comparison result of SEM images of perovskite films prepared by traditional annealing and the method of the present invention.

[0031] In the figure: 1. Box body; 2. Front cover; 3. Air inlet; 4. Air inlet temperature detector; 5. Exhaust hole; 6. Solvent atmosphere channel; 7. Table temperature detector; 8. Base; 9. Air inlet channel; 10. Exhaust channel; 11. Rear cover; 12. Organic solvent volatilization box. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] like Figure 1-2 As shown, a drying annealing device for preparing a thermal cycle perovskite film includes a box body 1, a front cover plate 2, an air inlet 3, an air inlet temperature detector 4, an exhaust hole 5, a solvent atmosphere channel 6, a table temperature detector 7, a substrate 8, an air inlet channel 9, an exhaust channel 10, a rear cover plate 11 and an organic solvent volatilization box 12.

[0034] Combination Figure 1 As shown, the front of the box body 1 is partitioned to separate multiple annealing chambers arranged in a transverse direction and independent of each other. Windows are provided in front of the multiple annealing chambers. A substrate 8 for carrying a perovskite film is placed on the table in each annealing chamber. A front cover plate 2 is provided at the window of each annealing chamber to isolate the annealing chamber from the external environment to form a closed space. An air intake channel 9 and an exhaust channel 10 are provided in the transverse direction at the top and middle positions of the rear of the box body 1. The air intake channel 9 and the exhaust channel 10 are both connected to the side of the box body 1 at one end. The air intake channel 9 is connected to the corresponding position of the rear wall of each annealing chamber. The high-temperature inert gas used for annealing is introduced into each annealing chamber by connecting to an external gas heating circulation device. The exhaust channel 10 is connected to the corresponding position of the rear wall of each annealing chamber. Exhaust holes 5 are provided to communicate with each annealing chamber. The original low-temperature air and the introduced high-temperature inert gas are discharged from each annealing chamber by connecting to an external gas heating circulation device.

[0035] Combination Figure 2As shown, a placement cavity is arranged at the bottom end of the rear of the box body 1 along the horizontal direction for storing an organic solvent volatilization box 12, and the organic solvent volatilization box 12 is used to store volatile organic solvents during annealing of the perovskite film. A window is arranged at the rear of the placement cavity, and a rear cover plate 11 is arranged at the window of the placement cavity, which is used to isolate the organic solvent volatilization box 12 from the external environment to form a closed space. Solvent atmosphere channels 6 are respectively arranged at the corresponding positions of the placement cavity and the rear walls of each annealing chamber for communicating with each other, so as to transport the volatile gas into each annealing chamber.

[0036] The box body 1 can be made of glass or stainless steel. An intake air temperature detector 4 is installed at the rear wall of each annealing chamber in the box body 1 near the air inlet 3 to monitor the intake air temperature in real time. A table temperature detector 7 is installed at the bottom of each annealing chamber in the box body 1 to monitor the table temperature in real time. The front cover plate 2 and the rear cover plate 11 can be pull-out cover plates, and handles are provided at the outer ends for easy pull-out operation. The material can be glass or stainless steel.

[0037] like Figure 1 to Figure 5 As shown, a method for preparing a thermal cycle perovskite film comprises the following steps:

[0038] Step 1: Prepare the perovskite precursor solution

[0039] 44.7 mg of CsBr, 27.8 mg of PbCl2, 36.7 mg of PbBr2 and 28.3 mg of PEABr were dissolved in 1 mL of DMSO solvent to prepare a perovskite precursor solution.

[0040] Step 2: Prepare perovskite film using perovskite precursor solution

[0041] S2.1, the substrate 8 is a rigid glass substrate or a PET flexible substrate or a smooth glass slide covered with a patterned ITO electrode, and the substrate 8 is cleaned in sequence using deionized water, anhydrous ethanol, acetone, isopropanol and anhydrous ethanol;

[0042] S2.2, blow the substrate 8 dry with nitrogen, irradiate the substrate 8 with plasma for 10 to 15 minutes, and then transfer the substrate 8 into a glove box filled with nitrogen;

[0043] S2.3, using a pipette to take 40-80 μL of the perovskite precursor solution, and drop it on the surface of the substrate 8;

[0044] S2.4. Prepare a perovskite film by spin coating the substrate 8. The spin coating conditions are a rotation speed of 3000 to 6000 rpm and a time of 25 to 45 s.

[0045] Step 3: Thermal cycle drying and annealing of the prepared perovskite film

[0046] S3.1. Store the volatile organic solvent in the organic solvent volatilization box 12 and load it into the placement cavity at the bottom of the rear side of the drying and annealing device. Close the front cover plate 2 and the rear cover plate 11 of the drying and annealing device. Connect the external gas heating circulation device through the air inlet channel 9 and the exhaust channel 10 to supply high-temperature inert gas to each annealing chamber in the box body 1. The air inlet flow rate is controlled at 2L / min. The high-temperature inert gas refers to the temperature controlled at 50-120°C, preferably nitrogen. The gas temperature is monitored in real time by the air inlet temperature detector 4 in each annealing chamber;

[0047] S3.2, prepare a plurality of substrates 8 carrying perovskite thin films in advance through steps 1 to 2, wait until the table temperature in each annealing chamber reaches 40-100°C, open the corresponding front cover plate 2, place the substrates 8 carrying perovskite thin films one by one on the table in the corresponding annealing chamber, and close the front cover plate 2 again, and monitor the table temperature in real time through the table temperature detector 7 in each annealing chamber;

[0048] S3.3. During the annealing process of the perovskite film, the volatile gas generated by the volatilized organic solvent is transported to each annealing chamber through the solvent atmosphere channel 6. The high-temperature inert gas circulates from top to bottom to dry the perovskite film until the annealing of the perovskite film on the surface of all substrates 8 is completed. Turn off the external gas heating circulation equipment, open the corresponding front cover plate 2, and take out the substrates 8 carrying the perovskite film one by one.

[0049] Different from the traditional bottom-up annealing process, combined with Figure 3 As shown in FIG. 1 , the thermal cycle perovskite film preparation method of the present invention adopts a top-down thermal cycle annealing method and uses a high-temperature inert gas drying method to prepare the perovskite film. The in-plane tensile strain of the perovskite film prepared by the conventional annealing method and the method of the present invention is compared. Figure 4 As shown, it can be seen that the method of the present invention helps to improve the interfacial tensile stress of the perovskite film, thereby improving the film quality and crystallization effect of the perovskite film. Figure 5 As shown, it can be seen that the perovskite film prepared by the method of the present invention has better film quality.

[0050] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms of assembly without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0051] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A drying and annealing device for preparing a thermal cycle perovskite film, characterized in that: The invention comprises a box body (1), a front cover plate (2), an air inlet channel (9), an exhaust channel (10), a rear cover plate (11) and an organic solvent volatilization box (12); a plurality of mutually independent annealing chambers are arranged horizontally in the front of the box body (1); windows are provided in the front of the plurality of annealing chambers; a substrate (8) is placed on the table in each annealing chamber; the front cover plate (2) is provided in the window of each annealing chamber; an air inlet channel (9) and an exhaust channel (10) are arranged horizontally at the top and middle position of the rear of the box body (1); one end of the air inlet channel (9) and the exhaust channel (10) are connected to the side of the box body (1); An air inlet hole (3) is respectively provided at a position corresponding to the rear wall of each annealing chamber, and an exhaust hole (5) is respectively provided at a position corresponding to the rear wall of each annealing chamber. The air inlet channel (9) and the exhaust channel (10) are connected to an external gas heating circulation device to realize the introduction and discharge of inert gas. A placement cavity is arranged at the bottom end of the rear of the box body (1) in a transverse direction and an organic solvent volatilization box (12) is stored. The organic solvent volatilization box (12) stores volatile organic solvents. A window is arranged at the rear of the placement cavity. The window of the placement cavity is provided with the rear cover plate (11). Solvent atmosphere channels (6) are respectively provided at positions corresponding to the placement cavity and the rear wall of each annealing chamber.

2. A drying and annealing device for preparing a thermal cycle perovskite film according to claim 1, characterized in that: An intake air temperature detector (4) is installed on the rear wall of each annealing chamber in the box body (1) adjacent to the intake hole (3).

3. The drying and annealing device for preparing a thermal cycle perovskite film according to claim 1, characterized in that: A table temperature detector (7) is installed at the bottom of each annealing chamber in the box (1).

4. The drying and annealing device for preparing a thermal cycle perovskite film according to claim 1, characterized in that: The front cover plate (2) and the rear cover plate (11) are draw-out cover plates.

5. The drying and annealing device for preparing a thermal cycle perovskite film according to claim 1, characterized in that: The substrate (8) is a rigid glass substrate or a PET flexible substrate or a smooth glass slide covered with a patterned ITO electrode.

6. A method for preparing a thermal cycle perovskite film, characterized in that: According to the drying and annealing device of claim 1, the method for preparing the perovskite film comprises the following steps: Step 1: Prepare perovskite precursor solution; Step 2: Prepare a perovskite film using a perovskite precursor solution, including: S2.1, clean the substrate (8) using deionized water, anhydrous ethanol, acetone, isopropanol and anhydrous ethanol in sequence; S2.2, blow dry the substrate (8) with nitrogen, irradiate with plasma for 10 to 15 minutes, and then transfer it into a glove box filled with nitrogen; S2.3, taking a perovskite precursor solution and dropping it onto the surface of the substrate (8); S2.4, preparing a perovskite film by spin coating; Step 3: Performing thermal cycle drying annealing on the prepared perovskite film, including: S3.

1. The volatile organic solvent is stored in the organic solvent volatilization box (12) and loaded into the placement cavity, the front cover plate (2) and the rear cover plate (11) are completely closed, and the external gas heating circulation device is connected through the air inlet channel (9) and the exhaust channel (10) to supply high-temperature inert gas to each annealing chamber in the box body (1), wherein the high-temperature inert gas refers to a temperature controlled at 50 to 120° C.; S3.2, when the table temperature in each annealing chamber reaches 40-100°C, open the corresponding front cover plate (2), place the substrate (8) carrying the perovskite film on the table in the annealing chamber, and close the front cover plate (2) again; S3.

3. During the annealing process of the perovskite film, the volatile gas generated by the volatilized organic solvent is transported to each annealing chamber through the solvent atmosphere channel (6). The high-temperature inert gas circulates from top to bottom to dry the perovskite film until the annealing of the perovskite film is completed. The external gas heating circulation equipment is turned off and the substrate (8) carrying the perovskite film is taken out.

7. A method for preparing a thermal cycle perovskite film according to claim 6, characterized in that: The perovskite precursor solution in step 1 is prepared by dissolving 44.7 mg of CsBr, 27.8 mg of PbCl2, 36.7 mg of PbBr2 and 28.3 mg of PEABr in 1 mL of DMSO solvent.

8. A method for preparing a thermal cycle perovskite thin film according to claim 6, characterized in that: The spin coating conditions in step 2 are a rotation speed of 3000 to 6000 rpm and a time of 25 to 45 s.

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