Preparation method of three-source co-evaporated inorganic perovskite film and solar cell

Abstract

The invention belongs to the field of photovoltaic devices, discloses a kind of three-source co-evaporation inorganic perovskite film and the preparation method of solar cell, wherein, the preparation method of inorganic perovskite film is under vacuum condition, utilizes three-source co-evaporation to prepare CsPbI3inorganic perovskite black phase film on substrate, wherein, three evaporation sources are respectively cesium iodide, lead iodide and additive, control the evaporation rate of the three, make the cesium iodide reaction component of deposited film corresponding acquisition, lead iodide reaction component and additive reaction component three's mol ratio be (1.05 1.30): 1: (0.05 0.20).The present invention is by introducing three-source co-evaporation, using organic ammonium salt as additive and as one of evaporation source, cooperates cesium iodide evaporation source and lead iodide evaporation source, utilizes vacuum three-source co-evaporation process to prepare inorganic perovskite film on substrate, can obtain room temperature stable inorganic perovskite black phase film.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaic devices, and more specifically, relates to a method for preparing a three-source co-evaporated inorganic perovskite film and a solar cell, providing a new solution for the design and preparation of perovskite solar cell devices. Background Art

[0002] The efficient development and utilization of clean energy is one of the major issues of this century, and the photovoltaic industry has also received widespread attention. As the current mainstream commercial silicon-based solar cells are about to reach their efficiency limit, tandem solar cells are one of the best options to break through this efficiency limit. That is, by combining silicon cells with wide-bandgap top cells, the absorption spectrum range of the entire cell is expanded to maximize the utilization of solar energy, thereby improving energy conversion efficiency. Calculations show that the optimal bandgap of the top cell absorption layer that matches the 1.12eV silicon cell is 1.7-1.76eV. Therefore, inorganic perovskite materials (CsPbI3) are one of the preferred materials. On the one hand, the efficiency of perovskite solar cells is currently increasing rapidly and is gradually approaching that of silicon cells, which has great potential in the photovoltaic field. On the other hand, the thermal and structural stability of inorganic perovskite materials are superior to those of organic-inorganic hybrid perovskite materials. At the same time, the current preparation of commonly used inorganic perovskite solar cells is mainly based on solution methods, which not only use toxic solvents but also have poor reproducibility. The vacuum thermal evaporation process for preparing inorganic perovskite materials offers the following advantages: a controllable and highly reproducible process; no toxic solvents are required, making it environmentally friendly; compatibility with existing industries; and avoiding exposure of humidity-sensitive inorganic perovskite materials to water vapor during the preparation process. However, the vacuum thermal evaporation process for inorganic perovskite materials still faces bottlenecks in the one-step preparation of room-temperature stable inorganic perovskite black phase (γ-CsPbI3, Pnam), and reliable methods are needed to improve this process. Summary of the Invention

[0003] In view of the above defects or improvement needs of the prior art, the object of the present invention is to provide a method for preparing an inorganic perovskite film and a solar cell by three-source co-evaporation, wherein by introducing three-source co-evaporation, an organic ammonium salt is used as an additive and as one of the evaporation sources (the organic ammonium salt includes dimethylamine hydroiodide (DMAI), dimethylamine hydrobromide (DMABr), dimethylamine hydrochloride (DMACl), phenyltrimethylammonium iodide (PTAI), phenyltrimethylammonium bromide (PTABr), phenyltrimethylammonium chloride (PTACl), benzylammonium iodide (BAI), benzylammonium bromide (BABr), benzylammonium chloride (BACl)), in combination with a cesium iodide evaporation source and a lead iodide evaporation source, and a vacuum three-source co-evaporation process is used to prepare an inorganic perovskite film on a substrate, and a room temperature stable inorganic perovskite black phase film can be obtained. On the one hand, this process avoids the use of toxic organic solvents, while also making process parameters more controllable and improving reproducibility. On the other hand, the high vacuum environment not only reduces environmental impurities, but also has a self-purification effect during the evaporation process, which is beneficial for the preparation of humidity-sensitive inorganic perovskite films. Furthermore, this process can be used to prepare the perovskite absorber layer of perovskite solar cells, resulting in photovoltaic devices with room-temperature stable inorganic perovskite black phases.

[0004] To achieve the above objectives, according to one aspect of the present invention, a method for preparing an inorganic perovskite film by three-source co-evaporation is provided, characterized in that the method is to prepare a CsPbI3 inorganic perovskite black phase film on a substrate by three-source co-evaporation under vacuum conditions, wherein the three evaporation source materials used in the three-source co-evaporation are cesium iodide (CsI), lead iodide (PbI2) and an additive, and the additive is an organic ammonium salt. The evaporation rates of the cesium iodide evaporation source, the lead iodide evaporation source and the additive evaporation source are controlled so that the molar ratio of the cesium iodide reaction component, the lead iodide reaction component and the additive reaction component obtained corresponding to the deposited film is (1.05-1.30):1:(0.05-0.20);

[0005] Wherein, the organic ammonium salt is selected from dimethylamine hydroiodide (DMAI), dimethylamine hydrobromide (DMABr), dimethylamine hydrochloride (DMACl), phenyltrimethylammonium iodide (PTAI), phenyltrimethylammonium bromide (PTABr), phenyltrimethylammonium chloride (PTACl), benzylammonium iodide (BAI), benzylammonium bromide (BABr), benzylammonium chloride (BACl).

[0006] As a further preferred embodiment of the present invention, during the co-evaporation process, the temperature of the substrate is always maintained at 40-100°C.

[0007] As a further preferred embodiment of the present invention, for the three evaporation sources, the plane where the cesium iodide evaporation source, the lead iodide evaporation source, and the additive evaporation source are located is parallel to the substrate surface, and the additive evaporation source is located on the perpendicular midline of the line connecting the cesium iodide evaporation source and the lead iodide evaporation source. The distance between the additive evaporation source and the midpoint of the line connecting the cesium iodide evaporation source and the lead iodide evaporation source is equal to the distance between the cesium iodide evaporation source or the lead iodide evaporation source and the midpoint. In addition, the line connecting the midpoint and the center of the substrate is perpendicular to the substrate surface.

[0008] As a further preferred embodiment of the present invention, the thickness of the perovskite film obtained by three-source co-evaporation is 240-800 nm.

[0009] According to another aspect of the present invention, a method for preparing a perovskite solar cell is provided, characterized in that the method comprises the following steps:

[0010] (1) preparing a hole transport layer on a transparent conductive electrode substrate;

[0011] (2) Under vacuum conditions, a CsPbI3 inorganic perovskite black phase film is prepared on the hole transport layer by three-source co-evaporation, thereby obtaining an inorganic perovskite absorption layer; wherein, the three evaporation source materials used in the three-source co-evaporation are cesium iodide (CsI), lead iodide (PbI2) and additives, and the evaporation rates of the cesium iodide evaporation source, the lead iodide evaporation source and the additive evaporation source are controlled so that the molar ratio of the cesium iodide reaction component, the lead iodide reaction component and the additive reaction component obtained in the deposited film is (1. 05-1.30):1:(0.05-0.20); wherein the additive is an organic ammonium salt, and the organic ammonium salt is selected from dimethylamine hydroiodide (DMAI), dimethylamine hydrobromide (DMABr), dimethylamine hydrochloride (DMACl), phenyltrimethylammonium iodide (PTAI), phenyltrimethylammonium bromide (PTABr), phenyltrimethylammonium chloride (PTACl), benzylammonium iodide (BAI), benzylammonium bromide (BABr), benzylammonium chloride (BACl);

[0012] (3) preparing a passivation layer on the perovskite absorption layer;

[0013] (4) preparing an electron transport layer on the passivation layer;

[0014] (5) Preparing a metal electrode layer on the electron transport layer.

[0015] As a further preferred embodiment of the present invention, the step (1) is to prepare a hole transport layer on a transparent conductive electrode substrate by a magnetron sputtering process or a solution spin coating method;

[0016] The step (3) specifically comprises preparing a passivation layer on the perovskite light absorbing layer by using a vacuum thermal evaporation process;

[0017] The step (4) specifically comprises preparing an electron transport layer on the passivation layer by using a vacuum thermal evaporation process;

[0018] The step (5) specifically involves preparing a metal electrode layer on the electron transport layer using a vacuum thermal evaporation process.

[0019] As a further preferred embodiment of the present invention, the transparent conductive electrode substrate in step (1) is pre-cleaned and dried.

[0020] Compared with the prior art, the above technical solution conceived by the present invention utilizes vacuum three-source co-evaporation, with organic ammonium salts including dimethylamine hydroiodide (DMAI), dimethylamine hydrobromide (DMABr), dimethylamine hydrochloride (DMACl), phenyltrimethylammonium iodide (PTAI), phenyltrimethylammonium bromide (PTABr), phenyltrimethylammonium chloride (PTACl), benzylammonium iodide (BAI), benzylammonium bromide (BABr), and benzylammonium chloride (BACl) as additives and as one of the evaporation sources, in combination with a cesium iodide evaporation source and a lead iodide evaporation source, to prepare an inorganic perovskite thin film on a substrate, and a room temperature stable inorganic perovskite black phase film can be obtained.

[0021] The CsPbI3 inorganic perovskite film obtained by the method of the present invention is directly a black phase (γ-CsPbI3, Pnam), does not require high-temperature post-annealing treatment, and has advantages in cost and repeatability; moreover, the introduction of additives is also conducive to the stability of the inorganic perovskite phase.

[0022] The method of the present invention uses a vacuum thermal evaporation co-evaporation process to replace the traditional solution method process. On the one hand, it can solve the problem of using toxic organic solvents in the current solution method for preparing perovskite films. On the other hand, it provides an alternative solution for the preparation of moisture-sensitive inorganic perovskite films, while improving process operability and repeatability. Unlike most scholars who mainly use the solution method to grow perovskite films, the present invention uses a vacuum thermal evaporation co-evaporation process, uses an organic ammonium salt as an additive as a third evaporation source, and cooperates with two evaporation sources, cesium iodide (CsI) and lead iodide (PbI2). The evaporation rates of the cesium iodide evaporation source, the lead iodide evaporation source, and the additive evaporation source are simultaneously controlled so that the molar ratio of the cesium iodide reaction component, the lead iodide reaction component, and the additive reaction component obtained in the deposited film is (1.05-1.30):1:(0.05-0.20). It can effectively provide sufficient core density on the substrate in a short time and achieve the deposition of CsPbI3 inorganic perovskite black phase film. In addition, the present invention can further effectively control the reaction between multiple evaporated materials and the in-situ growth of perovskite nuclei by preferably controlling the substrate temperature in the three-source co-evaporation process to 40-100°C, ensuring that the target reaction product with good crystallinity (i.e., CsPbI3 black phase film) can be successfully obtained.

[0023] In summary, the present invention prepares inorganic perovskite thin films through a vacuum vapor phase three-source co-evaporation process. This process is not only organic solvent-free and environmentally friendly, but also directly produces stable black-phase inorganic perovskites, providing a better process option for moisture-sensitive inorganic perovskites. This method is particularly suitable for the preparation of efficient, stable, environmentally friendly, controllable, and highly reproducible perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of three-source co-evaporation of perovskite film.

[0025] Figure 2 This is a top view of the evaporation chamber for three-source co-evaporation of perovskite film.

[0026] Figure 3 Schematic diagram of the device structure of a perovskite solar cell.

[0027] Figure 4 This is the current density-voltage curve of the perovskite solar cell device prepared by three-source co-evaporation corresponding to Example 4 under a light intensity of AM1.5G.

[0028] Figure 5 This is a comparison chart of the X-ray diffraction spectra of the perovskite film prepared by three-source co-evaporation in step (4) of Example 4 and the standard γ-CsPbI3.

[0029] Figure 6The initial state of the perovskite film prepared by three-source co-evaporation in step (4) of Example 4 and the actual state after being placed in a nitrogen box for one month; wherein, Figure 6 (a) corresponds to the initial state after the three-source co-evaporation is completed. Figure 6 (b) corresponds to the state after being placed in a nitrogen box for one month.

[0030] In the figure, the meanings of the various reference numerals are as follows: 1 is a conductive substrate for depositing a hole transport layer, 2 is a PbI2 evaporation source, 3 is a CsI evaporation source, 4 is a DMAI (or DMABr, or DMACl, or PTAI, or PTABr, or PTACl, or BAI, or BABr, or BACl) evaporation source; 102 is a transparent conductive electrode substrate, 104 is a hole transport layer, 106 is a perovskite absorption layer, 108 is a passivation layer, 110 is an electron transport layer, and 112 is a metal electrode layer. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0032] In general, to prepare inorganic perovskite films and corresponding solar cells, ITO conductive glass or FTO conductive glass can be used as a transparent conductive electrode, and a hole transport layer (NiOx, PTAA, PEDOT:PSS, Me-4PACz, etc.) is prepared on the transparent conductive electrode substrate by magnetron sputtering or solution spin coating. Subsequently, the transparent conductive glass deposited with the hole transport layer is used as a substrate, and the inorganic perovskite absorption layer is prepared by a vacuum three-source co-evaporation method. The passivation layer (LiF), electron transport layer (C60 / BCP) and metal electrode layer (Ag or Au or Cu) are then prepared by a vacuum thermal evaporation process to complete the preparation of the perovskite solar cell. This process has high repeatability and operability and can be reliably produced on a large scale.

[0033] The method for preparing an inorganic perovskite film by three-source co-evaporation in the present invention may include the following steps: preparing an inorganic perovskite film on a substrate 1 by a vacuum three-source co-evaporation method, preheating the substrate to 40-100°C, and using CsI, PbI2 and DMAI (or DMABr, or DMACl, or PTAI, or PTABr, or PTACl, or BAI, or BABr, or BACl) as raw material evaporation sources, respectively, wherein the molar ratio of the cesium iodide reaction component, the lead iodide reaction component and the additive reaction component obtained by controlling their evaporation rates in the deposited film is (1.05-1.30):1:(0.05-0.20). Taking the Qihui evaporator (model PD-450S-A) as an example, the evaporation rate ratio of CsI, PbI2 and DMAI (or DMABr, or DMACl, or PTAI, or PTABr, or PTACl, or BAI, or BABr, or BACl) can be controlled to be (1.13-1.28):1:(0.27-1.33), corresponding to a molar ratio of (1.05-1.30):1:(0.05-0.20). For example, the evaporation rate ratio can be 1.2:1:0.37, corresponding to a molar ratio of 1.2:1:0.07 (of course, due to different parameter settings of different evaporators, the specific evaporation rate ratio may vary when the molar ratio is the same); in addition, the thickness of the deposited film can be 240-800 nm (the thickness can be 300 nm in particular).

[0034] The following are specific embodiments:

[0035] Example 1

[0036] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0037] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0038] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 40 °C.

[0039] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and DMAI were adjusted to and After the rate stabilizes, the substrate baffle is opened to start evaporation; when the total thickness displayed by the CsI and PbI2 evaporation sources is 300 nm, the substrate baffle is closed to end the evaporation of the perovskite layer (the reason why only the total thickness displayed by the CsI and PbI2 evaporation sources is considered is that when the three sources of CsI, PbI2 and DMAI are co-evaporated, the evaporation of CsI and PbI2 will crosstalk with the rate detection of DMAI, resulting in a particularly large display rate of DMAI, which is not conducive to recording the thickness, otherwise the thickness deviation will be very large; at the same time, since the actual doping molar concentration of DMAI is low, it has little effect on the thickness of the perovskite film, so the total thickness can be determined only by the evaporation thickness of the CsI and PbI2 sources; the same is true for subsequent embodiments).

[0040] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0041] (6) C60 (fullerene) and BCP (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline) were deposited on the LiF passivation layer by vacuum thermal evaporation process. The evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0042] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0043] Example 2

[0044] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0045] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0046] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 40 °C.

[0047] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and DMAI were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0048] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0049] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0050] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0051] Example 3

[0052] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0053] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0054] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 40 °C.

[0055] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and DMAI were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0056] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0057] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0058] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0059] Example 4

[0060] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0061] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0062] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50°C.

[0063] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and DMAI were adjusted to and After the rate stabilizes, the substrate baffle is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is 300nm, the substrate baffle is closed to end the perovskite layer evaporation. At the same time, the sample is tested by XRD, and the results are as follows Figure 5 shown.

[0064] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0065] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0066] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0067] Example 5

[0068] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0069] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0070] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, and preheat the substrate to 100°C.

[0071] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and DMAI were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0072] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0073] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0074] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0075] Example 6

[0076] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0077] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0078] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50 °C.

[0079] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and DMABr were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0080] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0081] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0082] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0083] Example 7

[0084] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0085] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0086] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50 °C.

[0087] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and DMACl were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0088] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0089] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0090] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0091] Example 8

[0092] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0093] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0094] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50 °C.

[0095] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and PTAI were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0096] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0097] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0098] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0099] Example 9

[0100] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0101] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0102] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50°C.

[0103] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and PTABr were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0104] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0105] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0106] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0107] Example 10

[0108] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0109] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0110] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50 °C.

[0111] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and PTACl were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0112] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0113] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0114] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0115] Example 11

[0116] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0117] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0118] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50 °C.

[0119] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and BAI are adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0120] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0121] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0122] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0123] Example 12

[0124] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0125] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0126] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50 °C.

[0127] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and BABr were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0128] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0129] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0130] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0131] Example 13

[0132] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0133] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0134] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 50 °C.

[0135] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI, PbI2 and BACl were adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the total thickness of the CsI and PbI2 evaporation sources is shown to be 300nm, the substrate shutter is closed to end the perovskite layer evaporation.

[0136] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0137] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 was The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0138] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100nm.

[0139] Comparative Example 1

[0140] (1) Prepare a transparent ITO conductive electrode substrate and soak it in diluted conductive glass cleaner, deionized water, ethanol, acetone, and ethanol in sequence, ultrasonically for 10 minutes each time. Then blow dry with a nitrogen gun and dry in an oven for 1 hour before use. Treat the dried ITO glass with oxygen plasma for 10 minutes.

[0141] (2) Prepare a 4 mg / ml PTAA chlorobenzene solution, spin-coat at a speed of 4000 rpm for 30 s, and anneal at 100°C for 10 min after the spin-coating.

[0142] (3) First, the ITO substrate with PTAA spin-coated was introduced into the vacuum chamber, and the vacuum was pumped to 3×10 -4 Pa below, preheat the substrate to 40 °C.

[0143] (4) By adjusting the current value applied to both ends of the evaporation source, the evaporation rates of CsI and PbI2 are adjusted to and After the rate stabilizes, the substrate shutter is opened to start evaporation; when the sum of the thicknesses displayed by the two sources is 300 nm, the substrate shutter is closed to end the evaporation of the perovskite layer.

[0144] (5) The LiF passivation layer was prepared on the perovskite absorption layer by vacuum thermal evaporation process, and the evaporation rate was The thickness is 1nm.

[0145] (6) C60 and BCP were prepared on the LiF passivation layer by vacuum thermal evaporation process, where the evaporation rate of C60 is The thickness is 20 nm; the evaporation rate of BCP is The thickness is 3nm.

[0146] (7) Silver is evaporated on the electron transport layer as a metal electrode layer at an evaporation rate of The thickness is 100 nm. The performance of the solar cells of the above embodiment and comparative example are as follows:

[0147]

[0148]

[0149] In addition, the perovskite film obtained in step (4) of each embodiment above was placed in a nitrogen box, and the black phase could be kept stable for more than one month. Figure 6 shown.

[0150] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing an inorganic perovskite thin film by three-source co-evaporation, characterized in that: The method is to prepare a CsPbI3 inorganic perovskite black phase thin film on a substrate by three-source co-evaporation under vacuum conditions, wherein the three evaporation source materials used in the three-source co-evaporation are cesium iodide (CsI), lead iodide (PbI2) and an additive, and the additive is an organic ammonium salt. The evaporation rates of the cesium iodide evaporation source, the lead iodide evaporation source and the additive evaporation source are controlled so that the molar ratio of the cesium iodide reaction component, the lead iodide reaction component and the additive reaction component obtained in the deposited film is (1.05-1.30):1:(0.05-0.20); the CsPbI3 inorganic perovskite black phase thin film obtained by the three-source co-evaporation does not require post-annealing treatment, belongs to the Pnam space group, and is stable at room temperature; Wherein, the organic ammonium salt is selected from dimethylamine hydroiodide (DMAI), dimethylamine hydrobromide (DMABr), dimethylamine hydrochloride (DMACl), phenyltrimethylammonium iodide (PTAI), phenyltrimethylammonium bromide (PTABr), phenyltrimethylammonium chloride (PTACl), benzylammonium iodide (BAI), benzylammonium bromide (BABr), benzylammonium chloride (BACl).

2. The preparation method according to claim 1, wherein During the co-evaporation process, the temperature of the substrate is always maintained at 40-100°C.

3. The preparation method according to claim 1, wherein For the three evaporation sources, the planes where the cesium iodide evaporation source, the lead iodide evaporation source, and the additive evaporation source are located are parallel to the substrate surface, and the additive evaporation source is located on the midpoint of the line connecting the cesium iodide evaporation source and the lead iodide evaporation source. The distance between the additive evaporation source and the midpoint of the line connecting the cesium iodide evaporation source and the lead iodide evaporation source is equal to the distance between the cesium iodide evaporation source or the lead iodide evaporation source and the midpoint. In addition, the line connecting the midpoint and the center of the substrate is perpendicular to the substrate surface.

4. The preparation method according to claim 1, wherein The thickness of the perovskite film obtained by three-source co-evaporation is 240-800nm.

5. A method for preparing a perovskite solar cell, characterized in that: The following steps are involved: (1) preparing a hole transport layer on a transparent conductive electrode substrate; (2) Under vacuum conditions, a CsPbI3 inorganic perovskite black phase film is prepared on the hole transport layer by three-source co-evaporation, thereby obtaining an inorganic perovskite absorption layer; wherein, the three evaporation source materials used in the three-source co-evaporation are cesium iodide (CsI), lead iodide (PbI2) and additives, and the evaporation rates of the cesium iodide evaporation source, the lead iodide evaporation source and the additive evaporation source are controlled so that the molar ratio of the cesium iodide reaction component, the lead iodide reaction component and the additive reaction component obtained in the deposited film is (1. 05-1.30):1:(0.05-0.20); wherein the additive is an organic ammonium salt, and the organic ammonium salt is selected from dimethylamine hydroiodide (DMAI), dimethylamine hydrobromide (DMABr), dimethylamine hydrochloride (DMACl), phenyltrimethylammonium iodide (PTAI), phenyltrimethylammonium bromide (PTABr), phenyltrimethylammonium chloride (PTACl), benzylammonium iodide (BAI), benzylammonium bromide (BABr), benzylammonium chloride (BACl); (3) preparing a passivation layer on the perovskite absorption layer; (4) preparing an electron transport layer on the passivation layer; (5) Preparing a metal electrode layer on the electron transport layer.

6. The preparation method according to claim 5, characterized in that: The step (1) specifically comprises preparing a hole transport layer on a transparent conductive electrode substrate by using a magnetron sputtering process or a solution spin coating method; The step (3) specifically comprises preparing a passivation layer on the perovskite light absorbing layer by using a vacuum thermal evaporation process; The step (4) specifically comprises preparing an electron transport layer on the passivation layer by using a vacuum thermal evaporation process; The step (5) specifically involves preparing a metal electrode layer on the electron transport layer using a vacuum thermal evaporation process.

7. The preparation method according to claim 5, characterized in that: The transparent conductive electrode substrate in step (1) is cleaned and dried in advance.

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