A perovskite diode with electro-optical and photo-electric conversion functions and a preparation method thereof

Abstract

The application discloses a perovskite diode with photoelectric conversion function and a preparation method thereof. The perovskite diode comprises a transparent substrate, a cathode, an electron transport layer, an interface layer, a perovskite active layer, a hole transport layer and an anode in sequence. The electron transport layer is zinc oxide or magnesium-doped zinc oxide. The interface layer is serine or phenethyl ammonium bromide, which is used for inhibiting the fluorescence quenching effect of zinc oxide or magnesium-doped zinc oxide on the perovskite. The perovskite active layer is prepared from a precursor solution containing AX, BX2 and serine, wherein A is a monovalent cation, B is a divalent metal cation and X is a monovalent anion. The application simultaneously realizes effective photoelectric conversion and electric-optical conversion functions in a single perovskite diode, and balanced photovoltaic and luminescent performances are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to a perovskite diode, in particular to a perovskite diode with electro-optical and photo-electric conversion functions and a preparation method thereof. BACKGROUND

[0002] The production and consumption of energy has become an important issue for the development of science and society, and has attracted great attention from the industry. Photovoltaic cells and light-emitting diodes based on photoelectric conversion are two important semiconductor devices in the field of solar energy utilization and energy consumption, and their technological development has a great influence on clean energy industry, display and lighting industry. Although photovoltaic cells and light-emitting diodes have similar device structures, their carrier dynamics processes are completely opposite, photovoltaic cells convert light energy into electrical energy, while light-emitting diodes convert electrical energy into light energy. Due to the limitations of traditional semiconductor materials, this photo-electric conversion technology and electro-optical conversion technology have been developed independently and in parallel, and it is difficult to integrate photovoltaic and light-emitting functions in a single device.

[0003] Metal halide perovskite, as a direct band gap semiconductor material with excellent performance, has been successfully applied to the preparation of high-performance photovoltaic cells and light-emitting diodes, and is expected to break through the technical bottleneck of semiconductor devices that can only realize one-way conversion of photo-electric or electro-optical, and provide a basis for constructing high-performance, low-cost semiconductor devices integrating photovoltaic and light-emitting functions. In a perovskite diode integrating photovoltaic and light-emitting functions, in order to ensure the effective reciprocity of the two physical processes of photo-electric conversion and electro-optical conversion, the perovskite active layer needs to have high-efficiency carrier recombination and dissociation capacity, and the transport layer adjacent thereto needs to have balanced carrier injection and extraction capacity. However, if the perovskite diode device adopts the structure of a photovoltaic cell, uses fullerene (such as C60, PCBM and C70, etc.) and metal oxide (such as tin oxide and zinc oxide, etc.) as an electron transport layer and directly contacts with the perovskite active layer, it will seriously quench the fluorescence of the perovskite, resulting in that the photovoltaic performance of the device is better than the light-emitting performance, and it is difficult to achieve a balance between the photoelectric conversion efficiency (PCE) and the light-emitting external quantum efficiency (EQE), thereby affecting the service life of the device. SUMMARY

[0004] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of the present application is to provide a perovskite diode with electro-optical and photo-electric conversion functions, which suppresses the fluorescence quenching effect of ZnO or ZnMgO on perovskite by introducing a serine or phenethylammonium bromide interface layer, simultaneously realizes effective photo-electric and electro-optical conversion functions in a single perovskite diode, and obtains balanced photovoltaic and light-emitting performance, so that the PCE and the EQE both exceed 15%.

[0005] Another object of the present application is to provide a preparation method of the perovskite diode with the electro-optical and optical-electrical conversion function.

[0006] The object of the present application is achieved by the following technical solutions.

[0007] The present application provides a perovskite diode with electro-optical and optical-electrical conversion function, which comprises a transparent substrate, a cathode, an electron transport layer, an interface layer, a perovskite active layer, a hole transport layer and an anode in sequence.

[0008] The electron transport layer is zinc oxide (ZnO) or magnesium-doped zinc oxide (ZnMgO).

[0009] The interface layer is serine or phenethyl ammonium bromide, which is used to inhibit the fluorescence quenching effect of zinc oxide or magnesium-doped zinc oxide on perovskite.

[0010] The perovskite active layer is prepared from a precursor solution containing AX, BX2 and serine, wherein A is a monovalent cation, B is a divalent metal cation, and X is a monovalent anion.

[0011] Preferably, the A is at least one of MA + (methylamine cation), FA + (formamidine cation) and Cs + (cesium cation); the B is at least one of Pb 2+ and Sn 2+ ; and the X is at least one of I - , Br - , Cl - , SCN - (thiocyanate ion), TFA - (trifluoroacetate ion) and CH3COO - (acetate ion).

[0012] Preferably, the hole transport layer is at least one of doped 2,2',7,7'-tetra[n,n-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) (doping material is tributyl phosphate (t-BP) and lithium bis-trifluoromethanesulfonimide (Li-TFSI)), poly(9,9-n-octyl-2,7-fluorene-alt-9-iso-octyl-3,6-carbazole) (PF8Cz) and poly[(N,N'-(4-n-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine)-alt-(9,9-di-n-octylfluorenyl-2,7-diyl)] (TFB).

[0013] Preferably, the anode is composed of two layers, the first layer is molybdenum oxide or 1,4,5,8,9,11-hexaazatriphenylhexanitrile, with a thickness of 1-20 nanometers; the second layer is a metal layer, with a thickness of 50-200 nanometers, and the metal is aluminum, silver or gold.

[0014] Preferably, the transparent substrate is glass or plastic.

[0015] Preferably, the cathode is one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium zinc oxide (IZO) and aluminum-doped zinc oxide (AZO).

[0016] The application also provides a preparation method of the perovskite diode with electro-optical and photo-electric conversion functions, comprising the following steps:

[0017] (1) mixing AX, BX2 and serine to dissolve, heating the solution to 40-100℃ and stirring, then cooling to room temperature, standing, taking the supernatant and filtering, and the filtrate is a precursor solution;

[0018] (2) directly spin-coating an ethanol solution containing zinc oxide or magnesium-doped zinc oxide on the cathode on the transparent substrate under air condition, and annealing at 100-150℃ to obtain an electron transport layer;

[0019] (3) directly spin-coating an aqueous solution of serine or benzyltrimethylammonium bromide on the electron transport layer under air condition, and annealing at 100-150℃ to obtain an interface layer;

[0020] (4) depositing the precursor solution on the interface layer by spin-coating method, and adding anti-solvent dropwise during the spin-coating process to accelerate the perovskite crystallization speed, and forming a perovskite active layer after annealing at 100-150℃;

[0021] (5) sequentially depositing a hole transport layer and an anode.

[0022] Preferably, in the precursor solution, the concentration of BX2 is 0.1-1.5 mol / L; and the molar ratio of serine, AX and BX2 is 0.01-1:0.1-10:1.

[0023] Preferably, in the ethanol solution containing zinc oxide or magnesium-doped zinc oxide, the concentration of zinc oxide or magnesium-doped zinc oxide is 5-50 mg / mL.

[0024] Preferably, the preparation of the hole transport layer is as follows:

[0025] dissolving a hole transport material in chlorobenzene, stirring the solution overnight, standing, taking the supernatant and filtering, and the filtrate is a hole transport layer solution; and depositing the hole transport layer on the perovskite active layer by spin-coating method.

[0026] Preferably, the concentration of the hole transport layer material solution is 5-100 mg / mL.

[0027] Preferably, the anode is prepared by sequentially depositing a layer of molybdenum oxide or HAT-CN and then a metal layer on the hole transport layer by vacuum evaporation method.

[0028] Preferably, the solvent of the precursor solution is one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), gamma-butyrolactone (GBL) and N-methyl pyrrolidone (NMP).

[0029] Preferably, the anti-solvent is one or more of ethyl acetate, methyl acetate, chlorobenzene, toluene and octane.

[0030] Preferably, the cathode on the transparent substrate in step (2) is subjected to ultraviolet ozone pretreatment, and the pretreatment time is 5-60 minutes.

[0031] Preferably, in step (2), the rotation speed of the spin coating is 2000-6000 revolutions per minute (rpm), the acceleration of the spin coating is 2000-6000 revolutions per minute per second (rpm / s), and the total time of the spin coating is 20-60 seconds; the annealing time is 1-90 minutes.

[0032] Preferably, in step (3), the rotation speed of the spin coating is 2000-6000 revolutions per minute (rpm), the acceleration of the spin coating is 2000-6000 revolutions per minute per second (rpm / s), and the total time of the spin coating is 20-60 seconds; the annealing temperature is 100-150℃, and the annealing time is 1-90 minutes.

[0033] Preferably, in step (4), the rotation speed of the spin coating is 2000-6000 revolutions per minute (rpm), the acceleration of the spin coating is 2000-6000 revolutions per minute per second (rpm / s), and the total time of the spin coating is 20-60 seconds; the annealing temperature is 100-150℃, the annealing time is 1-90 minutes, and the dropping time of the anti-solvent is 5-20 seconds.

[0034] Preferably, in the preparation of the hole transport layer, the rotation speed of the spin coating is 2000-6000 revolutions per minute (rpm), the acceleration of the spin coating is 2000-6000 revolutions per minute per second (rpm / s), and the total time of the spin coating is 20-60 seconds.

[0035] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0036] (1) The perovskite diode with the function of electric-optical and optical-electric conversion of the application suppresses the fluorescence quenching effect of ZnO or ZnMgO on perovskite by introducing a serine or phenethylammonium bromide interface layer, realizes effective optical-electric and electric-optical conversion functions in a single perovskite diode, and obtains balanced photovoltaic and luminescent performance, so that the PCE and EQE are both more than 15%, and the balanced photovoltaic and luminescent performance is beneficial to prolong the service life of the perovskite diode with the function of electric-optical and optical-electric conversion.

[0037] (2) The perovskite diode with the function of electric-optical and optical-electric conversion of the application modifies the perovskite active layer by an additive, effectively adjusts the exciton binding energy, makes the perovskite active layer have high and balanced carrier recombination and dissociation capacity, reduces the potential barrier between the perovskite active layer and the transport layer, and enables the carriers at the interface to realize injection and extraction balance. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The structure schematic diagram of the perovskite diode with the function of electric-optical and optical-electric conversion prepared for the embodiment 1 of the application.

[0039] Figure 2 The external quantum efficiency-current density curve diagram of the serine as the interface layer and the perovskite diode without the interface layer as the luminescent device prepared for the embodiment 1 of the application.

[0040] Figure 3 The current density-voltage characteristic curve diagram of the serine as the interface layer and the perovskite diode without the interface layer as the photovoltaic device prepared for the embodiment 1 of the application under the condition of simulated AM 1.5G 1 solar illumination (100 mW cm -2 ).

[0041] Figure 4 The photoluminescence fluorescence spectrum diagram of the perovskite thin film with the serine as the interface layer and the perovskite diode without the interface layer prepared for the embodiment 1 of the application.

[0042] Figure 5 The external quantum efficiency-current density curve diagram of the perovskite diode corresponding to the serine aqueous solution with the concentration of 1 mg / ml and 2 mg / ml as the luminescent device prepared for the embodiment 2 of the application.

[0043] Figure 6 The current density-voltage characteristic curve diagram of the perovskite diode corresponding to the serine aqueous solution with the concentration of 1 mg / ml and 2 mg / ml as the photovoltaic device prepared for the embodiment 2 of the application under the condition of simulated AM 1.5G 1 solar illumination (100 mW cm -2 ).

[0044] Figure 7 The external quantum efficiency-current density curve of the interface layer material prepared in Example 3 of the present invention, which is phenylethyl ammonium bromide and an interfaceless perovskite diode, is shown.

[0045] Figure 8 The interface layer material prepared for Example 3 of the present invention is phenylethyl ammonium bromide, and the interface-free perovskite diode is used as a photovoltaic device in simulated AM 1.5G 1 solar illumination (100mW cm⁻¹). -2 Current density-voltage characteristic curve under the given conditions.

[0046] Figure 9 The external quantum efficiency-current density curves of perovskite diodes with and without serine in the precursor solution as light-emitting devices are shown in the figure. Figure 9 As shown.

[0047] Figure 10 Perovskite diodes with and without serine in the precursor solution were used as photovoltaic devices under simulated AM 1.5G 1 solar illumination (100mW cm⁻¹). -2 Current density-voltage characteristic curve under the condition. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0049] Example 1

[0050] This embodiment provides a method for fabricating a perovskite diode with electro-optical and photo-electrical conversion functions, including the following steps:

[0051] (1) Preparation of perovskite precursor solution: Serine, FAI (methyldihydroiodide) and PbI2 (lead iodide) were dissolved in DMF in a molar ratio of 0.1:1.8:1, wherein the molar concentration of PbI2 was 0.7 mol / L. The solution was stirred on a hot plate at 50°C for 12 hours, then cooled to room temperature, allowed to stand, and the supernatant was filtered.

[0052] (2) Place the clean ITO glass in an ultraviolet ozone cleaner for 15 minutes, then spin coat a ZnO ethanol solution with a concentration of 25 mg / ml onto the treated ITO glass at a spin coating speed of 4000 rpm for 30 seconds, and anneal at 120°C for 20 minutes to obtain a ZnO layer as an electron transport layer.

[0053] (3) A 1 mg / ml serine aqueous solution was spin-coated onto the ZnO electron transport layer at a spin speed of 4000 rpm for 30 seconds, and then annealed at 120°C for 10 minutes to obtain the interface layer.

[0054] (4) The perovskite precursor solution prepared in step (1) was spin-coated on the prepared interface layer at a rotation speed of 6000 rpm, and the total spin-coating time was 20 seconds. At the 5th second, 20 microliters of chlorobenzene was quickly added to the perovskite film as an anti-solvent. After spin-coating, the perovskite active layer was obtained by annealing at 150°C for 1 minute.

[0055] (5) A 25 mg / ml Spiro-OMeTAD (doped with 2.6 mg / ml t-BP and 520 mg / ml Li-TFSI) chlorobenzene solution was prepared and spin-coated on the perovskite active layer prepared in step (3) at a rotation speed of 4000 rpm for 30 seconds to obtain a hole transport layer.

[0056] (5) A 25 mg / ml Spiro-OMeTAD (doped with 2.6 mg / ml t-BP and 520 mg / ml Li-TFSI) chlorobenzene solution was prepared and spin-coated on the perovskite active layer prepared in step (3) at a rotation speed of 4000 rpm for 30 seconds to obtain a hole transport layer.

[0057] The perovskite diode with electro-optical and photo-electric conversion functions prepared in this example is shown in FIG. 1, which includes a transparent substrate 1, a cathode 2, an electron transport layer 3, an interface layer 4, a perovskite active layer 5, a hole transport layer 6, and a composite anode 7 in sequence. Figure 1

[0058] To illustrate the effect of the interface layer of the present application, a comparative sample without an interface layer was prepared in this example: step (3) was not performed in the above steps.

[0059] Figure 2 The external quantum efficiency-current density curve of the perovskite diode with and without a serine interface layer prepared in this example as a light-emitting device is shown in FIG. 2.

[0060] Figure 3 The current density-voltage characteristic curve of the perovskite diode with and without a serine interface layer prepared in this example as a photovoltaic device under simulated AM 1.5G 1 sun illumination (100 mW cm -2 ) conditions is shown in FIG. 3.

[0061] Figure 4 The photoluminescence fluorescence spectrum of the perovskite thin film with and without a serine interface layer prepared in this example is shown in FIG. 4.

[0062] The device performance parameters of the perovskite diode with and without a serine interface layer prepared in this example are shown in Table 1.

[0063] Table 1. Device performance parameters

[0064] ​

[0065] From the above results, it can be seen that by adding a serine interface layer between the perovskite active layer and the electron transport layer, the fluorescence spectrum intensity of the perovskite film is obviously enhanced (as shown in FIG. 2B), the fluorescence quenching effect of the metal oxide electron transport layer ZnO on the perovskite is inhibited, the potential barrier between the perovskite active layer and the transport layer is reduced, and the balance of injection and extraction of carriers at the interface is achieved. The maximum electroluminescence external quantum efficiency reaches 18.4%, and the photoelectric conversion efficiency of the perovskite diode reaches 15.4%. Figure 4

[0066] Example 2

[0067] The structure and preparation method of the device of this example are basically the same as those of Example 1, except that the concentration of the serine aqueous solution for preparing the serine interface layer is 2 mg / ml. The performance parameters of the perovskite diodes corresponding to the concentrations of 1 mg / ml and 2 mg / ml of the serine aqueous solution are shown in Table 2.

[0068] Table 2. Performance parameters of the prepared devices

[0069]

[0070] The external quantum efficiency-current density curve of the perovskite diode corresponding to the concentration of 1 mg / ml and 2 mg / ml of the serine aqueous solution as a light-emitting device is shown in FIG. 3B. Figure 5

[0071] The current density-voltage characteristic curve of the perovskite diode corresponding to the concentration of 1 mg / ml and 2 mg / ml of the serine aqueous solution as a photovoltaic device under simulated AM 1.5G 1 sun illumination (100 mW cm -2 ) conditions is shown in FIG. 3C. Figure 6

[0072] From the above results, it can be seen that when the concentration of the interface layer serine is 2 mg / ml, the maximum electroluminescence external quantum efficiency of the perovskite diode reaches 16.8%, and the photoelectric conversion efficiency reaches 16.3%, exhibiting more balanced light-emitting and photovoltaic performance.

[0073] Example 3

[0074] The device structure and preparation method of this example are basically the same as those of Example 1, except that the interface layer material is phenethylammonium bromide, and the concentration of the phenethylammonium bromide aqueous solution is 1 mg / ml. The performance parameters of the perovskite diodes with the interface layer material of phenethylammonium bromide and without the interface are shown in Table 3.

[0075] Table 3. Performance parameters of the prepared devices

[0076] ​​​

[0077] The external quantum efficiency-current density curves of a perovskite diode with an interface layer material of phenylethyl ammonium bromide and no interface are shown in the figure. Figure 7 As shown.

[0078] When the interface layer material is phenylethyl ammonium bromide and the interface-free perovskite diode is used as a photovoltaic device, it is compared with the simulation of AM1.5G 1 solar illumination (100mW cm⁻¹). -2 The current density-voltage characteristic curve under the condition is shown in the figure. Figure 8 As shown.

[0079] The results above show that by adding phenylethyl ammonium bromide as an interface layer between the electron transport layer and the perovskite active layer, the luminescence and photovoltaic performance of the perovskite diode are improved. The maximum electroluminescence external quantum efficiency reaches 14.1%, and the photoelectric conversion efficiency reaches 14.3%, which has a similar effect to serine as an interface layer, and also shows a balanced luminescence and photovoltaic performance.

[0080] Comparative Example

[0081] To illustrate the role of serine in the precursor solution in this invention, the following two types of perovskite diodes without an interface layer were prepared according to the following steps in this comparative example:

[0082] (1) Preparation of perovskite precursor solution: Serine, FAI (methyldihydroiodide) and PbI2 (lead iodide) were dissolved in DMF in a molar ratio of 0.1:1.8:1, with the molar concentration of PbI2 being 0.7 mol / L. The solution was stirred on a hot plate at 50°C for 12 hours, then cooled to room temperature, allowed to stand, and the supernatant was filtered.

[0083] (2) Place the clean ITO glass in an ultraviolet ozone cleaner for 15 minutes, then spin coat a ZnO ethanol solution with a concentration of 25 mg / ml onto the treated ITO glass at a spin coating speed of 4000 rpm for 30 seconds, and anneal at 120°C for 20 minutes to obtain a ZnO layer.

[0084] (3) Spin-coat the prepared perovskite precursor solution in step (1) onto the prepared ZnO layer at a speed of 6000 rpm for a total spin-coating time of 20 seconds. At the 5th second, quickly drop 20 μL of chlorobenzene onto the perovskite film as an anti-solvent. After spin-coating, anneal at 150°C for 1 minute to obtain the perovskite active layer.

[0085] (4) 25 mg / ml Spiro-OMeTAD (doped with 2.6 mg / ml t-BP and 520 mg / ml Li-TFSI) chlorobenzene solution was prepared and spin-coated on the perovskite active layer prepared in step (3) at 4000 rpm for 30 seconds to obtain a hole transport layer.

[0086] (5) A 5 nm MoOx layer and a 100 nm Ag electrode were respectively deposited on the hole transport layer prepared in step (4) by a vacuum evaporation method to obtain a perovskite diode with electro-optical and photo-electric conversion functions.

[0087] The performance of the two kinds of perovskite devices was compared as shown in Table 4, with the perovskite diode without the addition of serine in the precursor solution as a control.

[0088] The external quantum efficiency-current density curve of the two kinds of perovskite devices as light-emitting devices is shown in Figure 9 .

[0089] The current density-voltage characteristic curve of the two kinds of perovskite devices as light-emitting devices under simulated AM 1.5G 1 sun illumination (100 mW cm -2 ) is shown in Figure 10 .

[0090] As can be seen from the above results, by using the serine additive to adjust the exciton binding energy, the perovskite active layer has high and balanced carrier recombination and dissociation ability, and the perovskite diode after the addition of serine exhibits excellent performance, with the maximum electroluminescent external quantum efficiency increased from 5.7% to 11.6% and the photoelectric conversion efficiency increased from 5.1% to 8.5%.

[0091] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods and are included in the protection scope of the present application.

Claims

1. A perovskite diode with electro-optical and photo-electric conversion functions, characterized in that, It consists of, in sequence, a transparent substrate, a cathode, an electron transport layer, an interface layer, a perovskite active layer, a hole transport layer, and an anode; The electron transport layer is zinc oxide or magnesium-doped zinc oxide; The interface layer is serine or phenylethyl ammonium bromide, which is used to suppress the fluorescence quenching effect of zinc oxide or magnesium-doped zinc oxide on perovskite. The perovskite active layer is prepared from a precursor solution containing AX, BX2 and serine, wherein A is a monovalent cation, B is a divalent metal cation, and X is a monovalent anion. A is MA + FA + and Cs + At least one of them; B is Pb 2+ and Sn 2+ At least one of them; X is I - ,Br - Cl - SCN - TFA - and CH3COO - At least one of them; The anode consists of two layers. The first layer is molybdenum oxide or 1,4,5,8,9,11-hexaazatriphenylhexanitrile, with a thickness of 1-20 nanometers. The second layer is a metal layer with a thickness of 50-200 nanometers, and the metal is aluminum, silver or gold.

2. The perovskite diode with electro-optic and photo-electric conversion functions according to claim 1, characterized in that, The hole transport layer is at least one of the following: doped 2,2',7,7'-tetratetra[n,n-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, poly(9,9-n-dioctyl-2,7-fluorene-alt-9-isooctyl-3,6-carbazole), and poly[(N,N'-(4-n-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine)-alt-(9,9-di-n-octylfluorene-2,7-diyl)]. The doping material in the doped 2,2',7,7'-tetratetra[n,n-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene is tributyl phosphate or lithium bis(trifluoromethanesulfonylimide).

3. The method for fabricating a perovskite diode with electro-optic and photo-electric conversion functions as described in any one of claims 1 to 2, characterized in that, Includes the following steps: (1) Mix and dissolve AX, BX2 and serine, heat the solution to 40~100℃ and stir, then cool to room temperature, let stand, take the supernatant and filter, the filtrate is the precursor solution; (2) An ethanol solution containing zinc oxide or magnesium-doped zinc oxide is directly spin-coated onto a cathode on a transparent substrate under air conditions, and then annealed at 100~150℃ to obtain an electron transport layer. (3) The aqueous solution of serine or phenylethyl ammonium bromide is directly spin-coated onto the electron transport layer under air conditions, and then annealed at 100~150℃ to obtain the interface layer. (4) The precursor solution is deposited on the interface layer by spin coating, and an anti-solvent is added dropwise during spin coating to accelerate the crystallization rate of perovskite. After annealing at 100~150℃, a perovskite active layer is formed. (5) Deposit the hole transport layer and the anode in sequence.

4. The preparation method according to claim 3, characterized in that, In the precursor solution, the concentration of BX2 is 0.1~1.5 mol / L; the molar ratio of serine, AX and BX2 is 0.01~1:0.1~10:

1.

5. The preparation method according to claim 3, characterized in that, The concentration of zinc oxide or magnesium-doped zinc oxide in the ethanol solution is 5-50 mg / mL.

6. The preparation method according to claim 3, characterized in that, The hole transport layer is fabricated as follows: Dissolve the hole transport material in chlorobenzene, stir the solution overnight, let it stand, take the supernatant and filter it. The filtrate is the hole transport layer solution. Deposit the hole transport layer solution onto the perovskite active layer by spin coating.

7. The preparation method according to claim 3, characterized in that, The concentration of the hole transport layer material solution is 5-100 mg / mL.

8. The preparation method according to claim 3, characterized in that, The anode is prepared by depositing a layer of molybdenum oxide or HAT-CN sequentially on the hole transport layer by vacuum evaporation, followed by depositing a metal layer to obtain a composite anode.

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