ABX3 type metal halide perovskite thin film, preparation method and photovoltaic device

Abstract

The invention discloses an ABX3 type metal halide perovskite thin film, a preparation method and a photovoltaic device. The film is prepared by an anti-solvent method; wherein organic molecules containing active halogen with the concentration of 0.1-50 mg / ml are added into the anti-solvent solution. According to the method, release of active halogen in organic molecules is utilized, the gradual evolution process of multiple metal halide complexes is regulated and controlled, generation of related defects such as halogen vacancies is inhibited, migration of halogen ions in a perovskite thin film is prevented, and uniform perovskite film forming is achieved; the perovskite photovoltaic device with high photoelectric conversion efficiency is realized by using the thin film provided by the invention, and the method is very suitable for industrial preparation of the large-area and high-performance perovskite photovoltaic device.

Description

Technical Field

[0001] The present invention relates to the field of perovskite photovoltaic technology, and in particular to an ABX3 type metal halide perovskite film prepared by regulating and utilizing organic molecules containing active halogens, and a photovoltaic device prepared by utilizing the film. Background Art

[0002] The development of clean energy is the foundation of low-carbon economy and sustainable development of human society in the future, and the development of low-cost, high-performance photoelectric conversion technology is one of the keys to achieving this goal. Organic-inorganic metal halide perovskites have the advantages of abundant material sources, simple preparation process, and high carrier mobility. They are a type of new material with great potential to promote the development of the energy field. However, in the current preparation process of perovskite films, the generation of high defect density restricts the transmission of carriers, and the photoelectric conversion efficiency of solar cells is still far below the Shockley-Quisser energy conversion limit (SQ limit). In addition, the poor uniformity of the film limits the preparation of large-area films and devices.

[0003] Therefore, it is necessary to further optimize perovskite materials and their preparation processes to improve device performance and stability. Summary of the invention

[0004] The purpose of the invention is to solve the deficiencies in the prior art and to provide an ABX3 type metal halide perovskite film.

[0005] Another object of the present invention is to provide a perovskite photovoltaic device with high photoelectric conversion efficiency prepared by using the above-mentioned ABX3 type metal halide perovskite film.

[0006] The object of the present invention is achieved in the following ways:

[0007] An ABX3 type metal halide perovskite film, characterized in that the film is prepared by an anti-solvent method; wherein an organic molecule containing active halogen is added to the anti-solvent solution, and the organic molecule can release active halogen during the film preparation process, thereby regulating the evolution of metal halide complexes during the perovskite film formation process; the concentration of the organic molecule containing active halogen in the anti-solvent solution is 0.1 to 50 mg / ml; the preferred concentration is 1 to 20 mg / ml, and the further preferred concentration is 5 to 10 mg / ml; in the ABX3 type perovskite structure, A is an organic or inorganic cation that can form a three-dimensional perovskite, B is a divalent metal cation, and X is a halogen anion. The above A is CH3NH3 + 、HC(NH2)2 + 、C(NH2)3 + , Cs + One or more of, B is Pb 2+ or Sn 2+One or a mixture of two cations, X is Cl - Br - ,I - One or more of .

[0008] The α position of the organic halogen in the above-mentioned organic molecule containing active halogen is a group with electron-withdrawing or conjugated properties; preferably, the α position of the organic halogen in the organic molecule containing active halogen is a carbonyl group, a benzene ring, a pyridine ring, an alkenyl group or an alkynyl group. It is further preferred that the above-mentioned organic molecule containing active halogen is ethyl α-iodophenylacetate, ethyl α-bromophenylacetate, methyl 2-bromopropionate, dimethyl chloromalonate, (1-bromoethyl)benzene, ethyl iodoacetate, iodoacetic anhydride, ethyl 2-chloropropionate, ethyl 2-bromopropionate, iodoacetic acid N-hydroxysuccinimide ester, diethyl 2,5-dibromoadipate, and ethyl 2-bromovalerate. One or more of iodoacetic acid, iodobromic acid, sodium iodoacetate, allyl iodide, 2-iodoacetamide, 3-(iodomethyl)pyridine, tert-butyl iodide, 4-nitrophenyl iodoacetic acid, N-iodosuccinimide, 5-(iodoacetamido)fluorescein and 1,3-diiodo-5,5-dimethylhydantoin, most preferably α-iodophenylethyl acetate or α-bromophenylethyl acetate. It can effectively regulate the uniform crystal growth of perovskite film, inhibit the generation of related defects such as halogen vacancies, reduce defects, and prevent the migration of halogen ions in the perovskite film.

[0009] Preferably, the anti-solvent is a non-polar volatile solvent; more preferably, it is chlorobenzene, ethyl acetate, toluene or propyl acetate.

[0010] The method for preparing the ABX3 type metal halide perovskite film comprises the following steps: dissolving AX and BX2 in a polar solvent at a molar ratio of 0.8 to 1.5:0.8 to 1.5 to obtain a precursor solution, wherein the concentration of the precursor solution is 0.9 to 1.3 mol / l. Then, the precursor solution is prepared by an anti-solvent method. An organic molecule containing active halogen is added to the anti-solvent at a concentration of 0.1 to 50 mg / ml.

[0011] The above reaction can be carried out at -10 to 25° C. AX is preferably one or both of FAI (FABr) and CsI (CsBr), and BX2 is preferably PbI2 (PbBr2). The molar ratio of AX to BX2 is preferably 1:1.

[0012] The mass ratio of the precursor solution to the organic molecules containing active halogen is 10-8000.

[0013] Preferably, the anti-solvent method is: in the process of preparing the perovskite film by one-step spin coating, the perovskite wet film is obtained by washing with an anti-solvent; or the perovskite solution is coated on the substrate by spin coating or scraping, and then immersed in the anti-solvent for 3 to 5 minutes to obtain the perovskite wet film; finally, the prepared wet film is annealed at 100° C. to 150° C. for 10 to 60 minutes. The anti-solvent washing can be performed by dripping the anti-solvent during the spin coating process.

[0014] The one-step spin coating method for preparing the thin film adopts a rotation speed of 1000-6000 rpm and a spin coating time of 10-600 s.

[0015] The scraping method is to prepare a wet film by scraper coating or slit coating, with a coating speed of 2 to 150 mm / s, a blade height of 50 to 400 μm, and a liquid injection speed of 10 to 1000 μl / s.

[0016] Preferably, the polar solvent is one of amide, sulfoxide, alcohol, sulfone, ester solvents or a mixed solvent in any proportion; the preferred solvent is ethanol, isopropanol, dimethoxyethanol, formamide, N,N-dimethylformamide, dimethyl sulfoxide, cyclopentane, tetramethylene sulfoxide, 1,3-dimethylpropylene urea, γ-butyrolactone, N-alkyl pyrrolidone, acetonitrile, methylamine acetate or a mixture thereof in any proportion; the most preferred solvent is one of DMF and DMSO or a mixture thereof in any proportion.

[0017] The metal halide perovskite photovoltaic device prepared by using the above perovskite film comprises a substrate layer, an electrode layer, an electrode modification layer, a hole transport-electron blocking layer, an electron transport-hole blocking layer and a functional layer, wherein the functional layer comprises at least a perovskite light absorption layer, and the perovskite light absorption layer is an ABX3 type metal halide perovskite film; the film is prepared by using an anti-solvent method; wherein organic molecules containing active halogens are added to the anti-solvent solution, and the concentration of the organic molecules containing active halogens in the anti-solvent solution is 0.1 to 50 mg / ml, and the α position of the organic halogen in the organic molecules containing active halogens is a group with electron-withdrawing or conjugated properties; in the ABX3 type perovskite structure, A is CH3NH3 + 、HC(NH2)2 + 、C(NH2) 3+ , Cs + One or more of, B is Pb 2+ or Sn 2+ One or a mixture of two cations, X is Cl - Br - ,I - The anti-solvent is a non-polar volatile solvent, preferably chlorobenzene, ethyl acetate, toluene or propyl acetate.

[0018] The anti-solvent is a non-polar volatile solvent, preferably chlorobenzene, ethyl acetate, toluene or propyl acetate.

[0019] Preferably, the substrate is rigid glass, a flexible substrate or a metal foil.

[0020] The preferred device structure is: glass substrate / FTO / SnO2 / FA 0.9 Cs 0.1 Pb(IBr)3 / Spiro-OMeTAD / MoO3 / Ag.

[0021] The device can be prepared as follows: clean the transparent conductive substrate FTO glass substrate.

[0022] ① Preparation of electron transport-hole blocking layer: Take 100ml ultrapure water in a 500ml volumetric flask, then add

[0023] 50 μL of thioglycolic acid (C2H4O2S) and 1.5 mL of HCl (37 wt%) were mixed and then shaken.

[0024] 1. Dissolve 2.5g of SnCl2·2H20 in the prepared solution; then add 2.5g of urea to make a mother solution. Put the FTO in a glass box, add the above 25ml mother solution to the glass box, and dilute it with 125ml ultrapure water. Then age it in a 90℃ oven for 3.5h. Take out the FTO glass sheet, ultrasonically clean it with ultrapure water for 5 minutes, then ultrasonically clean it with isopropanol (IPA) for 5 minutes, blow dry it with a dry nitrogen flow, and anneal it on a 170℃ hot plate for 1 hour for use.

[0025] ② Preparation of anti-solvent solution: Prepare a chlorobenzene solution containing ethyl α-iodophenylacetate.

[0026] ③ Preparation of perovskite light-absorbing layer: In a nitrogen glove box, take the perovskite precursor solution and use a one-step spin coating method, and add the above anti-solvent in the last 10 seconds of spin coating. Subsequently, the obtained perovskite film is annealed on a hot plate at 100℃~150℃ for 10~20min and cooled to room temperature.

[0027] ④ Preparation of hole transport-electron blocking layer: Weigh Spiro-OMeTAD powder, add 1ml chlorobenzene, then add 18μl Li-TFSI (520mg / ml dissolved in acetonitrile), 29μl FK209 (300mg / ml dissolved in acetonitrile) and 30μl 4-tert-butylpyridine, stir for 1h to fully dissolve. The above solution is prepared by one-step spin coating method, the rotation speed is 4000rpm, and the spin coating time is 30s, and the hole transport-electron blocking layer covering the perovskite film can be obtained.

[0028] ⑤ Preparation of electrode modification layer and electrode: The prepared perovskite film was transferred to a vacuum evaporation chamber for preparation of electrode modification layer (MoO3) and electrode (Ag) at an atmospheric pressure of 6×10 -7 Torr, when evaporating the electrode modification layer,

[0029] The evaporation rate was controlled below 0.01 nm / s, the thickness was 4.5 nm, and the evaporation rate of the electrode was maintained at 0.1 nm / s.

[0030] Compared with the prior art, the present invention has the following beneficial effects: the present invention utilizes an organic molecule containing active halogen to effectively combine with a metal halide complex to accelerate the nucleation of perovskite, inhibit the formation of fluorescence quenching centers during the crystal growth of perovskite, and thus improve the photoelectric conversion efficiency of perovskite photovoltaic devices. In addition, the present invention regulates the uniform film formation process of perovskite, and the preparation of perovskite photovoltaic devices using the thin film of the present invention achieves a photoelectric conversion efficiency of up to 24.37% for perovskite solar cells, which is very useful for the industrial production of large-area, flexible perovskite films and photovoltaic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of a perovskite photovoltaic device provided in an embodiment of the present invention;

[0032] Figure 2 This is a SEM image of the perovskite film morphology of Example 1 of the present invention;

[0033] Figure 3 This is a SEM image of the cross-sectional morphology of the perovskite film of Example 1 of the present invention;

[0034] Figure 4 is a graph showing the evolution of the absorption intensity of the metal halide complex during the perovskite film formation process of Example 1 of the present invention;

[0035] Figure 5 Schematic diagram of the evolution of the perovskite metal halide complex of Example 1 of the present invention;

[0036] Figure 6 A two-dimensional spectrum of the photoluminescence intensity of the perovskite film of Example 1 of the present invention;

[0037] Figure 7 is a current-voltage curve diagram of the perovskite photovoltaic device of Example 1 of the present invention;

[0038] Figure 8 is a current-voltage curve diagram of the perovskite photovoltaic device according to Example 2 of the present invention;

[0039] Fig. 9 is a current-voltage curve diagram of the perovskite photovoltaic device of Example 3 of the present invention;

[0040] Fig.10 This is a SEM image of the perovskite film morphology of Example 4 of the present invention;

[0041] Fig.11 This is a SEM image of the perovskite film morphology of Example 5 of the present invention;

[0042] Fig.12 This is a SEM image of the perovskite film morphology of Example 6 of the present invention;

[0043] Fig.13 A two-dimensional spectrum of the photoluminescence intensity of the perovskite film of Example 6 of the present invention;

[0044] Fig.14 is a current-voltage curve diagram of the perovskite photovoltaic device of Example 6 of the present invention;

[0045] Fig.15 This is a SEM image of the perovskite film morphology of Example 7 of the present invention;

[0046] Fig.16 This is a SEM image of the perovskite film morphology of Example 8 of the present invention;

[0047] Fig.17 This is a SEM image of the perovskite film morphology of Comparative Example 1 of the present invention;

[0048] Fig.18 It is a two-dimensional spectrum of the photoluminescence intensity of the perovskite film of Comparative Example 1 of the present invention;

[0049] Fig.19 This is a current-voltage curve diagram of the perovskite photovoltaic device of Comparative Example 1 of the present invention;

[0050] Fig. 20 This is a SEM image of the perovskite film morphology of Comparative Example 2 of the present invention;

[0051] Fig.21 It is a two-dimensional spectrum of the photoluminescence intensity of the perovskite film of Comparative Example 2 of the present invention;

[0052] Fig. 22 This is a current-voltage curve diagram of the perovskite photovoltaic device of Comparative Example 2 of the present invention;

[0053] Fig.23 It is a two-dimensional spectrum of the photoluminescence intensity of the perovskite film of Comparative Example 3 of the present invention;

[0054] Fig.24 This is a current-voltage curve diagram of the perovskite photovoltaic device of Comparative Example 3 of the present invention;

[0055] Fig.25 It is a two-dimensional spectrum of the photoluminescence intensity of the perovskite film of Comparative Example 4 of the present invention;

[0056] Fig.26 This is a current-voltage curve diagram of the perovskite photovoltaic device of Comparative Example 4 of the present invention; DETAILED DESCRIPTION

[0057] The present invention is described in detail below in conjunction with specific embodiments.

[0058] The following example solution preparation method:

[0059] The perovskite ABX3 precursor solution is prepared by mixing AX and BX2 in a certain ratio in a solvent to form different concentrations. + , Cs + 、MA + and FA + Any one of the multiple types), B is the fourth main group metal (Pb 2+ , Sn 2+ ) or transition metal ions (Cu 2+ , Ni 2+ ,Co 2+ , Fe 2+ , Mn 2+ ,Eu 2+ ), X is a halogen element (Cl, Br, I). The solvent refers to any one or more of dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and γ-butyrolactone. The concentration refers to the molar concentration of the solute (perovskite ABX3) in the solution is 0.9 to 1.3 mol / l.

[0060] Example 1

[0061] FA 0.9 Cs 0.1 Preparation of Pb(IBr)3 perovskite solar cells: Perovskite FA 0.9 Cs 0.1 The Pb(IBr)3 precursor solution was prepared by dissolving FAI(FABr), CsI(CsBr), and PbI2(PbBr2) in DMF / DMSO (4:1 V / V) at a molar ratio of 0.9:0.1:1 and stirring at room temperature for 4 h to obtain a 1.3 mol / L perovskite precursor solution.

[0062] The entire device structure is described as: glass substrate / FTO / SnO2 / FA 0.9 Cs 0.1 Pb(IBr)3 / Spiro-OMeTAD / MoO3 / Ag.

[0063] The device preparation method is as follows:

[0064] Perovskite photovoltaic device structure Figure 1As shown, it includes a transparent conductive substrate layer, on which an electron transport-hole blocking layer, a perovskite light absorbing layer, a hole transport-electron blocking layer, an electrode modification layer and an electrode are sequentially arranged.

[0065] ① The substrate is fluorine-doped tin oxide (FTO) conductive glass, the square resistance of the FTO film is 15Ω, and the film thickness is 20-200nm. The transparent conductive substrate FTO glass is ultrasonically cleaned twice using isopropanol, acetone and ethanol solutions respectively, and after the FTO glass is dried using a high-pressure nitrogen flow, the FTO is transferred to an oxygen plasma surface cleaning machine for oxygen plasma cleaning.

[0066] ② Preparation of electron transport-hole blocking layer: Take 100ml ultrapure water in a 500ml volumetric flask, then add 50μL thioglycolic acid (C2H4O2S) and 1.5mL HCI (37wt% mass fraction) and shake well. Then dissolve 0.55g SnCl2·2H20 in the prepared solution; then add 2.5g urea to make a mother solution. Put FTO in a glass box, add the above 25ml mother solution to the glass box, and add 125ml ultrapure water to dilute.

[0067] Then, the FTO glass sheet was aged in an oven at 90°C for 3.5 h. The FTO glass sheet was taken out and ultrasonically cleaned with ultrapure water for 5 minutes, and then ultrasonically cleaned with isopropanol (IPA) for 5 minutes. After being dried with a stream of dry nitrogen, the glass sheet was dried at 170°C.

[0068] Anneal on a hot plate for 1 hour and set aside.

[0069] ③ Preparation of anti-solvent solution: Add 5 mg of ethyl α-iodophenylacetate to 1 ml of chlorobenzene, shake well to prepare a 5 mg / ml anti-solvent solution for use.

[0070] ④ Preparation of perovskite light-absorbing layer: In a nitrogen glove box, take the perovskite precursor solution and use a one-step spin coating method with a rotation speed of 6000 rpm and a spin coating time of 10 seconds. During the spin coating process, the above anti-solvent is added dropwise. Subsequently, the obtained perovskite film is annealed on a hot plate at 150°C for 10 minutes and cooled to room temperature.

[0071] ⑤ Preparation of hole transport-electron blocking layer: weigh 73 mg of Spiro-OMeTAD powder, add 1 ml of chlorobenzene, add 18 μl of Li-TFSI (520 mg / ml dissolved in acetonitrile), 29 μl of FK209 (300 mg / ml dissolved in acetonitrile) and 30 μl of 4-tert-butylpyridine, and stir for 1 hour to fully dissolve. The above solution is used to prepare a thin film by one-step spin coating, with a rotation speed of 4000 rpm and a spin coating time of 30 seconds to obtain a hole transport-electron blocking layer covering the perovskite film.

[0072] ⑥ Preparation of electrode modification layer and electrode: The prepared perovskite film was transferred to a vacuum evaporation chamber for preparation of electrode modification layer (MoO3) and electrode (Ag) at an atmospheric pressure of 6×10 -7 Torr, when evaporating the electrode modification layer, the evaporation rate is controlled below 0.01nm / s, the thickness is 4.5nm, and the evaporation rate of the electrode is maintained at 0.1nm / s, and the thickness is 80nm.

[0073] The prepared perovskite photovoltaic device was tested for its current-voltage characteristics in a glove box:

[0074] The morphology of the perovskite film regulated by α-iodophenylacetic acid ethyl ester in this example is shown in FIG. Figure 2 The cross-sectional morphology of the perovskite film is shown in Figure 3 , it can be seen that a single perovskite grain runs through the entire perovskite light-absorbing layer. X ] 2-X The evolution process of perovskite film formation is shown in Figure 4 , it can be seen that [PbI X ] 2-X The low-coordination complex gradually grows to the high-coordination complex and realizes the complete transformation to the high-coordination complex. The transformation diagram is shown in Figure 5 . 2D photoluminescence mapping (PLmapping) of perovskite films can be found at Figure 6 , it can be seen that the photoluminescence intensity of the perovskite film is relatively uniform. The JV curve of the perovskite photovoltaic device regulated by α-iodophenylacetic acid ethyl is shown in Figure 7 , it can be seen that the photoelectric conversion efficiency is up to 24.37%.

[0075] Example 2

[0076] The difference between this embodiment and embodiment 1 is that the concentration of the chlorobenzene solution containing ethyl α-iodophenylacetate is 0.1 mg / ml, and the film is prepared by a one-step spin coating method, the rotation speed is 1000 rpm, the spin coating time is 40 s, and the above chlorobenzene solution is added dropwise during the spin coating process. Subsequently, the obtained perovskite wet film is annealed on a heating plate at 100° C. for 60 min and cooled to room temperature. The photovoltaic device preparation method refers to embodiment 1.

[0077] The JV curve of the perovskite photovoltaic device prepared by regulating 0.1 mg / ml α-iodophenylethyl acetate is shown in Figure 8 , it can be seen that the photoelectric conversion efficiency reaches 23.68%.

[0078] Example 3

[0079] The difference between this embodiment and embodiment 1 is that the concentration of the chlorobenzene solution containing ethyl α-iodophenylacetate is 50 mg / ml. The film is prepared by a one-step spin coating method, with a rotation speed of 1000 rpm and a spin coating time of 600 s, and the above chlorobenzene solution is added dropwise during the spin coating process. Subsequently, the obtained perovskite film is annealed on a heating plate at 150° C. for 10 min and cooled to room temperature. The other methods of the photovoltaic device refer to embodiment 1.

[0080] The JV curve of the perovskite photovoltaic device prepared by regulating 50mg / ml α-iodophenylethyl acetate is shown in Fig. 9 , it can be seen that the photoelectric conversion efficiency reaches 23.28%.

[0081] Example 4

[0082] This example is different from Example 1 in that the perovskite film is prepared by a slit coating method. Specifically, the perovskite precursor solution is placed in a syringe with an injection speed of 10 μl / s, a coating speed of 2 mm / s, and a blade height of 50 μm. The obtained perovskite wet film is soaked in a chlorobenzene antisolvent of α-iodophenylethyl acetate for 3 minutes, wherein the concentration of the chlorobenzene solution of α-iodophenylethyl acetate is 0.1 mg / ml. The obtained perovskite film is annealed on a heating plate at 150°C for 10 minutes and cooled to room temperature. The remaining steps in the preparation process of other devices refer to Example 1.

[0083] The morphology of perovskite films is as follows Fig.10 As shown, the perovskite film treated by immersion in the anti-solvent is dense and there is no residual PbI2.

[0084] Example 5

[0085] The difference between this example and Example 4 is that the coating speed is 150 mm / s, the blade height is 400 μm, and the injection speed is 1000 μl / s.

[0086] The morphology of perovskite films is as follows Fig.11 As shown, the perovskite film treated by immersion in the anti-solvent is dense and there is no residual PbI2.

[0087] Example 6

[0088] The difference between this embodiment and embodiment 1 is that the perovskite film is prepared by spin coating of ethyl α-bromophenylacetate in chlorobenzene antisolvent, wherein the concentration of the ethyl α-bromophenylacetate in chlorobenzene solution is 8.2 mg / ml. The photovoltaic device preparation method is referred to embodiment 1.

[0089] The morphology of the perovskite film regulated by ethyl α-bromophenylacetate in this example is shown in Fig.12 , it can be seen that the grains are densely arranged without holes, and the grain size is about 200 to 400 nm.

[0090] 2D photoluminescence mapping of perovskite films (PL mapping) Fig.13 It can be seen that the luminescence intensity of the perovskite film prepared using ethyl α-bromophenylacetate is uniform.

[0091] The JV curve of the perovskite photovoltaic device prepared by α-bromophenylacetic acid ethyl ester is shown in Fig.14 , it can be seen that the photoelectric conversion efficiency reaches 23.27%.

[0092] Example 7

[0093] The difference between this embodiment and embodiment 1 is that the perovskite film is prepared by a one-step spin coating method using 2-iodo-2-methylpropionic acid ethyl chlorobenzene antisolvent, wherein the concentration of 2-iodo-2-methylpropionic acid ethyl chlorobenzene solution is 21 mg / ml. The photovoltaic device preparation method is referred to embodiment 1.

[0094] The morphology of the perovskite film regulated by ethyl 2-iodo-2-methylpropionate in this example is shown in Fig.15 , it can be seen that the grains are densely arranged without holes.

[0095] Example 8

[0096] The difference between this example and Example 1 is that the spin-coated perovskite wet film is immersed in a chlorobenzene antisolvent of ethyl α-iodophenylacetate for 3 minutes, wherein the concentration of the chlorobenzene solution of ethyl α-iodophenylacetate is 5 mg / ml. The obtained perovskite film is annealed on a hot plate at 150° C. for 20 minutes and cooled to room temperature. The other device preparation steps refer to Example 1.

[0097] The morphology of perovskite films is as follows Fig.16 As shown, the perovskite film treated by immersion in the anti-solvent is dense and there is no residual PbI2.

[0098] Comparative Example 1

[0099] This example is different from Example 1 in that the perovskite film is prepared using chlorobenzene antisolvent containing ethyl phenylacetate, wherein the concentration of ethyl phenylacetate is 5 mg / ml. Compared with the structure of ethyl phenylacetate α-iodophenylacetate, the structure of ethyl phenylacetate does not contain organic active iodine. The remaining steps in the device preparation process refer to Example 1.

[0100] Fig.17 As shown, the perovskite film is dense, but there is still a lot of PbI2 remaining at the grain boundaries. Fig.18 It shows that the photoluminescence intensity of the perovskite film prepared by treating ethyl phenylacetate is uneven and the overall luminescence intensity is weak. Fig.19 JV curve of the perovskite photovoltaic device prepared using chlorobenzene antisolvent of ethyl phenylacetate, with a photoelectric conversion efficiency of 20.04%.

[0101] Comparative Example 2

[0102] The present example is different from Example 1 in that the perovskite film is prepared using a chlorobenzene antisolvent containing phenylethylamine hydroiodic acid containing an ionic halogen, wherein the ratio of the concentration of phenylethylamine hydroiodic acid to the concentration of perovskite is 0.03:1.

[0103] Fig. 20 As shown, the perovskite film is dense, but there is still a lot of PbI2 remaining at the grain boundaries. Fig.21 It shows that the photoluminescence intensity of the perovskite film prepared by ionic halogen treatment is uneven and the luminescence intensity is weak. Fig. 22 JV curve of perovskite photovoltaic device prepared using chlorobenzene antisolvent of phenylethylamine hydroiodic acid, with a photoelectric conversion efficiency of 22.35%.

[0104] Comparative Example 3

[0105] The present example is different from Example 1 in that the perovskite film is prepared using a chlorobenzene antisolvent containing an ammonium iodide salt of an ionic halogen, wherein the ratio of the concentration of the ammonium iodide salt to the concentration of the perovskite is 0.03:1.

[0106] Fig.23 It shows that the photoluminescence intensity of the perovskite film prepared by ionic halogen treatment is uneven and the luminescence intensity is weak.

[0107] Fig.24 JV curve of perovskite photovoltaic device prepared using chlorobenzene antisolvent of ammonium iodide salt, with a photoelectric conversion efficiency of 20.09%.

[0108] Comparative Example 4

[0109] The difference between this example and Example 1 is that the perovskite film is prepared using chlorobenzene antisolvent containing ethyl α-iodophenylacetate, wherein the concentration of ethyl α-iodophenylacetate is 60 mg / ml. The remaining steps in the device preparation process refer to Example 1.

[0110] Fig.25 The photoluminescence intensity of the perovskite film prepared by treating with chlorobenzene antisolvent with high concentration of α-iodophenylethyl acetate is shown to be uneven.

[0111] Fig.26 The JV curve of the perovskite photovoltaic device prepared using a high concentration of ethyl α-iodophenylacetate in chlorobenzene antisolvent, with a photoelectric conversion efficiency of 19.24%.

Claims

1. An ABX3 type metal halide perovskite film, characterized in that The film is prepared by an anti-solvent method; wherein organic molecules containing active halogens are added to the anti-solvent solution, the concentration of the organic molecules containing active halogens in the anti-solvent solution is 0.1-50 mg / ml, the α position of the organic halogen in the organic molecules containing active halogens is a group with electron-withdrawing or conjugated properties; in the ABX3 type perovskite structure, A is CH3NH3 + 、HC(NH2)2 + 、C(NH2) 3+ , Cs + One or more of, B is Pb 2+ or Sn 2+ One or a mixture of two cations, X is Cl - Br - ,I - One or more of .

2. The ABX3 type metal halide perovskite thin film according to claim 1, characterized in that The α position of the organic halogen in the organic molecule containing active halogen is a carbonyl group, a benzene ring, a pyridine ring, an alkenyl group or an alkynyl group.

3. The ABX3 type metal halide perovskite thin film according to claim 1, characterized in that: The organic molecules containing active halogen are ethyl α-iodophenylacetate, ethyl α-bromophenylacetate, methyl 2-bromopropionate, dimethyl chloromalonate, (1-bromoethyl)benzene, ethyl iodoacetate, iodoacetic anhydride, ethyl 2-chloropropionate, ethyl 2-bromopropionate, N-hydroxysuccinimide iodoacetate, diethyl 2,5-dibromoadipate, and ethyl 2-bromovalerate. One or more of iodoacetic acid, iodobromic acid, sodium iodoacetate, allyl iodide, 2-iodoacetamide, 3-(iodomethyl)pyridine, tert-butyl iodide, 4-nitrophenyl iodoacetic acid, N-iodosuccinimide, 5-(iodoacetamido)fluorescein and 1,3-diiodo-5,5-dimethylhydantoin.

4. The ABX3 type metal halide perovskite thin film according to claim 1, characterized in that: The anti-solvent is a non-polar volatile solvent; preferably chlorobenzene, ethyl acetate, toluene or propyl acetate.

5. A method for preparing the ABX3 type metal halide perovskite thin film according to claim 1, characterized in that The method comprises the following steps: dissolving AX and BX2 in a polar solvent at a molar ratio of 0.8-1.5:0.8-1.5 to obtain a perovskite precursor solution, wherein the concentration of the precursor solution is 0.9-1.3 mol / l; and then preparing a perovskite film by an anti-solvent method; wherein organic molecules containing active halogens are added to the anti-solvent at a concentration of 0.1-50 mg / ml.

6. The method for preparing a metal halide perovskite thin film according to claim 5, characterized in that The anti-solvent method is as follows: in the process of preparing the perovskite film by one-step spin coating, the perovskite wet film is obtained by washing with an anti-solvent; or the perovskite liquid film is obtained by spin coating or scraping method, and then immersed in the anti-solvent for 3 to 5 minutes; finally, the prepared wet film is annealed at 100 to 150°C for 10 to 60 minutes; the one-step spin coating method adopts a rotation speed of 1000 to 6000 rpm and a spin coating time of 10 to 600 s to prepare the film; the scraping method is to prepare the wet film by scraper coating or slit coating, the coating speed is 2 to 150 mm / s, the blade height is 50 to 400 μm, and the injection speed is 10 to 1000 μl / s.

7. The method for preparing a perovskite thin film according to claim 5, characterized in that: The polar solvent is ethanol, isopropanol, dimethoxyethanol, formamide, N,N-dimethylformamide, dimethyl sulfoxide, cyclopentane, tetramethylene sulfoxide, 1,3-dimethylpropyleneurea, γ-butyrolactone, N-alkylpyrrolidone, acetonitrile, methylamine acetate or any mixture thereof.

8. The method for preparing a perovskite thin film according to claim 7, characterized in that: The polar solvent is one of DMF and DMSO or a mixture thereof in any proportion.

9. A metal halide perovskite photovoltaic device prepared using the perovskite film of claim 1, comprising a substrate layer, an electrode layer, an electrode modification layer, a hole transport-electron blocking layer, an electron transport-hole blocking layer and a functional layer, wherein the functional layer at least comprises a perovskite light absorption layer, characterized in that The perovskite light absorption layer is an ABX3 type metal halide perovskite film; the film is prepared by an anti-solvent method; wherein organic molecules containing active halogens are added to the anti-solvent solution, the concentration of the organic molecules containing active halogens in the anti-solvent solution is 0.1-50 mg / ml, and the α position of the organic halogen in the organic molecules containing active halogens is a group with electron-withdrawing or conjugated properties; in the ABX3 type perovskite structure, A is CH3NH3 + 、HC(NH2)2 + 、C(NH2) 3+ , Cs + One or more of, B is Pb 2+ or Sn 2+ One or a mixture of two cations, X is Cl - Br - ,I - One or more of .

10. The metal halide perovskite photovoltaic device according to claim 9, characterized in that: The substrate is rigid glass, a flexible substrate or a metal sheet.

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