CN106684247A - Perovskite solar cell and preparation method thereof - Google Patents

Abstract

The invention discloses a perovskite solar cell and a preparation method thereof. The perovskite solar cell comprises a transparent conductive substrate, a hole transport layer, a modification layer, a perovskite layer, an electron transport layer, a barrier layer and a metal electrode. The present invention uses imidazole-based ionic liquids to modify PEDOT:PSS, NiO _x , and the surface of the hole transport layer. Comparing the atomic force microscope images before and after modification, the surface morphology after modification is smoother, which is beneficial to suppress the recombination of dark current . The perovskite layer in the present invention adopts a new perovskite material 3MAI: PbAc ₂ xH ₂ O (0≤x≤3), at low temperature (<100ºC) through rapid preheating of the substrate and perovskite The heating of the precursor solution is heat-assisted spin coating (HASP) preparation, which is conducive to increasing the size of perovskite grains and reducing defects between perovskite grains, thereby significantly improving the efficiency of perovskite cells. The photoelectric conversion efficiency of the final battery device is >19%, the efficiency of the flexible device is 10.8%, and there is no hysteresis effect. This preparation method has great application prospects.

Description

A kind of perovskite solar cell and preparation method thereof

technical field

The invention relates to the technical field of solar cells, in particular to a perovskite solar cell and a preparation method thereof.

technical background

So far, the photoelectric conversion efficiency of perovskite solar cells that has been reported has reached 22.1%. As the third generation of solar cells, perovskite solar cells have attracted more and more attention because of their high photoelectric conversion efficiency, low cost and easy preparation. However, most of the current high-efficiency perovskite solar cells are positive structures based on TiO ₂ as the electron transport layer, and this material needs to be sintered at a high temperature above 400 ºC, and the battery device will produce obvious hysteresis effects. This greatly limits the application prospects of flexible perovskite solar cells, and when preparing perovskite thin films, harmful solvents such as chlorobenzene and toluene, which are toxic to the environment, are often used to treat the surface of perovskite thin films, which greatly hinder Commercial development of perovskite solar cells.

Most of the high-efficiency perovskite solar cells currently obtained are based on high-purity imported lead iodide as the lead source, and then FAI, PbBr ₂ , MAI are used to continuously optimize various ratios of doping. This type of lead source and dopant materials They are often more expensive, and when preparing perovskite films with lead iodide as the lead source, whether it is a positive structure similar to FTO/TiO2/Perovskite/Spiro-Ometad/Au, or similar to ITO/HTM/Perovskite/ The ETM/Au inverted structure is mostly processed by anti-solvent method, that is, a large amount of environmentally harmful solvents such as chlorobenzene and toluene are used to clean the surface of the perovskite. This has greatly limited the development of perovskite solar cells, both in terms of cost and environmental protection.

Contents of the invention

The purpose of the present invention is to provide a low-cost and more environmentally friendly high-efficiency perovskite solar cell to address the shortcomings of the above-mentioned prior art.

Another object of the present invention is to provide a method for preparing a high-efficiency perovskite solar cell with a simple preparation process, high practical value, low cost and applicable to flexible substrates.

To achieve the above object, the technical solution of the present invention is: the perovskite solar cell has a cathode transparent conductive substrate, a hole transport layer, an ionic liquid modification layer, a perovskite light-absorbing layer, an electron transport layer, a barrier layer and a metal electrode.

Transparent conductive substrates include FTO, ITO, ITO-PEN, ITO-PET and other glass and flexible conductive substrates, hole transport layers include PEDOT:PSS, NiOx, hole modification layers include 1-ethyl-3-methylimidazolium salt, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium iodide. The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ ·xH ₂ O (0≤x≤3), based on lead acetate (PbAc ₂ ·xH ₂ O) and formazan containing different crystal water Aminoiodine (MAI) is dissolved in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%. At low temperature (<100ºC), through The rapid preheating of the substrate and the heating of the perovskite precursor solution are heat-assisted spin-coating techniques to prepare the perovskite layer. The electron transport layer is prepared by spin coating of PC ₆₁ BM chlorobenzene solution (20mg/ml), the barrier layer is mainly obtained by spin coating of BCP (0.1-0.6mg/ml dissolved in isopropanol), and the metal electrode is mainly It is prepared by thermal evaporation and vacuum deposition of gold and silver under the condition of vacuum degree <10 ^-5 Pa.

In the further design scheme, the hole transport layer is 40-70nm, the ionic liquid modification layer is 5-10nm, the perovskite light-absorbing layer is 200-500nm, the electron transport layer is 30-60nm, the barrier layer BCP is 5-10nm, and the metal electrode is 80-120nm .

In a further design scheme, the perovskite light-absorbing layer is spin-coated with a new perovskite material PbAc ₂ ·xH ₂ O:3CH ₃ NH ₂ I solution, wherein the ratio of crystal water is 0≤x≤ 3. At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, that is, heat-assisted spin coating technology, in which the substrate is preheated at 90ºC for 5 minutes, and the perovskite precursor The solution was preheated at 60-80ºC for 5-10min. Then anneal at 90ºC for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer (thickness 200-500nm).

The preparation method of the above-mentioned perovskite solar cell includes the following specific steps.

(1) Etching the conductive layer of the transparent electrode: use an infrared laser with a wavelength of 1000 nanometers to etch an insulating band on the transparent electrode, so that a positive electrode area and a negative electrode area that are not connected to each other are formed on the electrode substrate.

(2) Preparation of hole transport layer: 1) Preparation of NiOx precursor: Accurately prepare 0.4mol/L ethanol solution of nickel oxalate (Ni(C ₂ O ₄ ) 3·6H ₂ O), then add magneton at 70 ºC Sealed and stirred for 12 hours for later use; preparation of PEDOT:PSS precursor: PEDOT:PSS aqueous solution (PVP Al 4083) was obtained through direct purchase. After the precursor solution is prepared, place the previously etched transparent conductive substrate in the UV processing instrument for 15 minutes, and after the substrate is cooled, completely cover the transparent electrode substrate with the prepared precursor solution by spin coating After that, anneal at 140ºC for 20min to form a hole transport layer (40-70nm).

(3) Ionic liquid modification layer: Spin-coat an ionic liquid with a mass concentration of 0.01-0.05 mg/ml on the hole transport layer, anneal at 130ºC for 15 minutes, and finally obtain an ionic liquid modification layer (thickness 5-10nm).

(4) Preparation of perovskite light-absorbing layer: First, the purchased lead acetate trihydrate (purity 99.99%) was heated in a glove box at 100ºC for 12 hours to remove water to obtain anhydrous lead acetate, and then anhydrous lead acetate It is prepared in a certain proportion with lead acetate trihydrate to finally obtain different proportions of crystal water lead acetate PbAc ₂ ·xH ₂ O (0≤x≤3). Prepared by dissolving lead acetate PbAc ₂ ·xH ₂ O (0≤x≤3) and methylamine iodine (MAI) containing different crystal water in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 Perovskite solution with a mass fraction of 30%-50%, at low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, that is, heat-assisted spin coating (HASP), The substrate is preheated at 90ºC for 5 minutes, and the perovskite precursor solution is preheated at 60-80ºC for 5-10 minutes. After one-step spin coating, anneal at 90ºC for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer (thickness 200-500nm).

(5) Preparation of electron transport layer: The electron transport layer was prepared by spin-coating method of PC ₆₁ BM (20mg/ml dissolved in chlorobenzene) (thickness 30-60nm).

(6) Preparation of barrier layer: the barrier layer is mainly BCP (0.1-0.6 mg/ml dissolved in isopropanol) obtained by spin coating (thickness 5-10 nm).

(7) Vapor-deposited metal electrodes: metal electrodes are mainly Au and Ag, prepared by thermal evaporation and vacuum deposition (thickness 80-120nm) under the condition of vacuum degree <10 ^-5 pa.

The operations in steps 2, 3, 4, 5, and 6 were all carried out on a spin coater. In the present invention, the photoelectric conversion efficiency of the battery device with the final effective area of 0.1cm ² conductive glass substrate is > 19.1%, and the efficiency of the battery device with 2cm ² conductive glass substrate is > 11.8%. At the same time, the 0.1cm ² flexible battery based on ITO-PEN substrate The photoelectric conversion efficiency of the device is 10.8%.

The present invention has the following outstanding beneficial effects:

The present invention uses four imidazole-based ionic liquids to modify the surface of hole transport layers such as PEDOT:PSS, NiOx, etc., and compares the scanning images of the atomic force microscope (AFM) before and after modification, and the surface morphology of the modified PEDOT:PSS and NiOx is obtained It is obviously improved and smoother, which is beneficial to the transmission of holes and the suppression of the recombination of dark current, further improving the photoelectric conversion efficiency of the battery. The preparation of the perovskite layer in the present invention is to adopt a kind of new perovskite material 3MAI: PbAc ₂ ·xH ₂ O (0≤x≤3) preparation, compared with high-purity imported lead iodide, the price cost of lead acetate It is 1/30 of it, and the perovskite layer is prepared at low temperature (<100ºC) by rapid preheating of the substrate and heating of the perovskite precursor solution, that is, heat-assisted spin coating (HASP). The preparation of perovskite by the traditional anti-solvent method often requires the use of harmful solvents such as chlorobenzene and toluene, which are toxic to the environment, to be added dropwise in the process of spin-coating perovskite. However, based on the new perovskite material 3MAI: PbAc ₂ ·xH ₂ O (0≤x≤3) adopts heat-assisted spin coating technology, which avoids the treatment of perovskite by harmful solvents such as chlorobenzene and toluene. This preparation method is more environmentally friendly. The most important thing is to use this method in The spin-coating process can accelerate the removal of some volatile by-products, which is conducive to increasing the size of perovskite grains and reducing defects between perovskite grains, thereby fully improving the current and opening voltage of perovskite cells. and fill factor. The photoelectric conversion efficiency of the final conductive glass substrate battery device modified by ionic liquids to the hole transport layer is as high as 19%. The perovskite solar cells prepared by this method are compared with the perovskite cells prepared by the traditional method. The stability in the air is significantly improved, and this preparation method is also suitable for the preparation of large-area glass and flexible perovskite solar cells, and can also obtain high efficiency. The device efficiency of 2cm ² conductive glass substrate cells is >11.8%, At the same time, the photoelectric conversion efficiency of the 0.1cm ² flexible battery device based on the ITO-PEN substrate is 10.8%. , so this preparation method has great application prospects.

Description of drawings

FIG. 1 is a schematic structural view of a novel perovskite solar cell according to an embodiment of the present invention. Among them, 1 is a transparent conductive substrate, 2 is a hole transport layer, 3 is an ionic liquid modification layer, 4 is a perovskite light-absorbing layer, 5 is an electron transport layer, 6 is a barrier layer, and 7 is a metal counter electrode.

Figure 2 is a comparison of atomic force microscope scans before and after PEDOT:PSS modification.

Fig. 3 is a TGA thermogravimetric analysis diagram of the perovskite material 3MAI: PbAc ₂ ·2.8H ₂ O and PbAc ₂ ·2.8H ₂ O.

Fig. 4 is a 0.1cm ² graph of the IV curve of a perovskite solar cell device on a conductive glass substrate.

Fig. 5 is the IV curve diagram of a 2cm ² conductive glass substrate perovskite solar cell device.

Fig. 6 is a 0.1cm ² flexible battery device IV curve based on ITO-PEN substrate.

detailed description

The present invention will be further explained below in conjunction with the examples, but the protection scope of the present invention is not limited to the following examples. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly used in other related technical fields, shall be equally included in the scope of patent protection of the present invention.

The structure of the perovskite solar cell device of this embodiment is shown in Figure 1. The device is a transparent conductive substrate 1, a hole transport layer 2, an ionic liquid modification layer 3, a perovskite light-absorbing layer 4, and an electron transport layer from bottom to top. layer, 5, barrier layer 6, metal electrode 7. The transparent conductive substrate is fluorine doped tin oxide (FTO), indium doped tin oxide (ITO), and ITO-PET, ITO-PEN flexible substrate, and the hole transport layer is mainly at least one of PEDOT:PSS, NiOx. The ionic liquid modification layer includes 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl At least one of the base-3-methylimidazolium iodide, the concentration of which in the DMF solution is 0.01-0.05 mg/ml, preferably 0.03 mg/ml. The perovskite light-absorbing layer material is mainly lead acetate PbAc ₂ ·xH ₂ O containing crystal water and methylamine iodine dissolved in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 30%. -50% perovskite solution, x=0~3, preferably x=2.8 H ₂ O, preferably 46% mass fraction. At low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, that is, heat-assisted spin coating technology, in which the substrate was preheated at 90ºC for 5min, and the perovskite precursor solution was Preheat at 60-80ºC for 5-10min. After one-step spin coating, anneal at 90°C for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer. The barrier layer is mainly BCP, and its solution concentration in isopropanol is 0.1-0.6 mg/ml, preferably 0.5 mg/ml. The metal electrode can be at least one of metal Au and Ag electrodes. The hole transport layer 2, the ionic liquid modification layer 3, the perovskite light-absorbing layer 4, the electron transport layer 5, and the barrier layer 6 are all sequentially stacked and prepared by a spin coating method. The metal counter electrode is prepared by evaporation method under high vacuum (<10 ^-5 Pa) condition, and the thickness can be 80-120nm.

The present invention will be further described below in conjunction with specific embodiments.

Example 1

The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ xH ₂ O, based on the content of different crystal water lead acetate (PbAc ₂ xH ₂ O) and methylamine iodine (MAI) in moles Dissolved in N,N-dimethylformamide (DMF) at a ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%, preferably x=2.8 H ₂ O, preferably with a mass fraction of 46%, in At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin coating. Metal Au is used as the metal electrode layer, and its specific preparation steps are as follows.

(1) On the cleaned UV-treated transparent FTO conductive glass substrate, a dense hole transport layer was obtained by spin-coating PEDOT:PSS aqueous solution, and heat-treated at 140 ºC for 20 minutes to form a hole transport layer with a thickness of 50nm about.

(2) A 0.03 mg/ml 1-ethyl-3-methylimidazolium iodide DMF solution was uniformly coated on the hole transport layer by spin coating. And heat treatment at 130 ºC for 15 minutes to form a modification layer of about 8nm.

(3) Dissolve lead acetate PbAc ₂ 2.8H ₂ O containing different crystal waters and methylamine iodide (MAI) in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 46 % perovskite solution, at low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin-coating technique, in which the substrate was preheated at 90ºC for 5min, Ca The titanium ore precursor solution was preheated at 75ºC for 5-10min. After spin-coating, anneal at 90ºC for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer with a thickness of about 400nm.

(4) A 20 mg/ml PC ₆₁ BM chlorobenzene solution was evenly spin-coated on the perovskite layer by a spin coating method to form an electron transport layer with a thickness of about 40 nm.

(5) Spin-coat 0.5 mg/ml BCP isopropanol solution evenly on the electron transport layer by spin coating to form a barrier layer with a thickness of about 8 nm.

(6) Preparation of metal electrodes: place the above-mentioned spin-coated multilayer film device in a thermal evaporation equipment, and after the vacuum degree reaches 10 ^-5 Pa, thermal evaporation (that is, evaporation) deposits metal Au to prepare a metal electrode. The thickness is 100nm.

The battery device was tested under the standard light condition of AM 1.5, and its energy conversion rate was 19.2%.

Example 2

The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ xH ₂ O, based on the content of different crystal water lead acetate (PbAc ₂ xH ₂ O) and methylamine iodine (MAI) in moles Dissolved in N,N-dimethylformamide (DMF) at a ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%, preferably x=2.8 H ₂ O, preferably with a mass fraction of 46%, in At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin coating. Metal Au is used as the metal electrode layer, and its specific preparation steps are as follows.

(1) On the cleaned UV-treated transparent FTO conductive glass substrate, a dense hole transport layer was obtained by spin-coating PEDOT:PSS aqueous solution, and heat-treated at 140 ºC for 20 minutes to form a hole transport layer with a thickness of 50nm about.

(2) A 0.03 mg/ml 1-ethyl-3-methylimidazolium chloride DMF solution was uniformly coated on the hole transport layer by spin coating. And heat treatment at 130 ºC for 15 minutes to form a modification layer of about 8nm.

(3) Dissolve lead acetate PbAc ₂ 2.8H ₂ O containing different crystal waters and methylamine iodide (MAI) in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 46 % perovskite solution, at low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin-coating technique, in which the substrate was preheated at 90ºC for 5min, Ca The titanium ore precursor solution was preheated at 75ºC for 5-10min. After spin-coating, anneal at 90ºC for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer with a thickness of about 400nm.

(4) Spin-coat 20mg/ml PC61BM chlorobenzene solution evenly on the perovskite layer by spin-coating method to form an electron transport layer with a thickness of about 40nm.

(5) Spin-coat 0.5 mg/ml BCP isopropanol solution evenly on the electron transport layer by spin coating to form a barrier layer with a thickness of about 8 nm.

(6) Preparation of the metal counter electrode: place the spin-coated multi-layer film device in the thermal evaporation equipment, and after the vacuum degree reaches 10 ^-5 Pa, thermal evaporation (that is, evaporation) deposits metal Au to prepare the metal counter electrode. Electrodes with a thickness of 100 nm.

The battery device was tested under the standard light conditions of AM 1.5 to obtain an energy conversion rate of 18.5%.

Example 3

The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ xH ₂ O, based on the content of different crystal water lead acetate (PbAc ₂ xH ₂ O) and methylamine iodine (MAI) in moles Dissolved in N,N-dimethylformamide (DMF) at a ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%, preferably x=2.8 H ₂ O, preferably with a mass fraction of 46%, in At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin coating. Metal Au is used as the metal electrode layer, and its specific preparation steps are as follows.

(1) On the cleaned UV-treated transparent FTO conductive glass substrate, a dense hole transport layer was obtained by spin-coating PEDOT:PSS aqueous solution, and heat-treated at 140 ºC for 20 minutes to form a hole transport layer with a thickness of 50nm about.

(2) A 0.03 mg/ml 1-ethyl-3-methylimidazolium bromide DMF solution was evenly coated on the hole transport layer by spin coating. And heat treatment at 130 ºC for 15 minutes to form a modification layer of about 8nm.

(3) Dissolve lead acetate PbAc ₂ 2.8H ₂ O containing different crystal waters and methylamine iodide (MAI) in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 46 % perovskite solution, at low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin-coating technique, in which the substrate was preheated at 90ºC for 5min, Ca The titanium ore precursor solution was preheated at 75ºC for 5-10min. After spin-coating, anneal at 90°C for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer with a thickness of about 400nm.

(4) A 20 mg/ml PC ₆₁ BM chlorobenzene solution was uniformly coated on the perovskite layer by spin coating to form an electron transport layer with a thickness of about 40 nm.

(5) Apply 0.5 mg/ml BCP isopropanol solution evenly on the electron transport layer by spin coating to form a barrier layer with a thickness of about 8 nm.

(6) Preparation of the metal counter electrode: place the spin-coated multi-layer film device in the thermal evaporation equipment, and after the vacuum degree reaches 10 ^-5 Pa, thermal evaporation (that is, evaporation) deposits metal Au to prepare the metal counter electrode. Electrodes with a thickness of 100 nm.

The battery device was tested under the standard light condition of AM 1.5, and its energy conversion rate was 18.2%.

Example 4

The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ xH ₂ O, based on the content of different crystal water lead acetate (PbAc ₂ xH ₂ O) and methylamine iodine (MAI) in moles Dissolved in N,N-dimethylformamide (DMF) at a ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%, preferably x=2.8 H ₂ O, preferably with a mass fraction of 46%, in At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin coating. Metal Au is used as the metal electrode layer, and its specific preparation steps are as follows.

(1) On the cleaned UV-treated transparent FTO conductive glass substrate, a dense hole transport layer was obtained by spin-coating PEDOT:PSS aqueous solution, and heat-treated at 140 ºC for 20 minutes to form a hole transport layer with a thickness of 50nm about.

(2) A 0.03 mg/ml 1-ethyl-3-methylimidazole acetate DMF solution was evenly coated on the hole transport layer by spin coating. And heat treatment at 130ºC for 15 minutes to form a modification layer of about 8nm.

(3) Dissolve lead acetate PbAc ₂ 2.8H ₂ O containing different crystal waters and methylamine iodide (MAI) in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 46 % perovskite solution, at low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin-coating technique, in which the substrate was preheated at 90ºC for 5min, Ca The titanium ore precursor solution was preheated at 75ºC for 5-10min. After spin-coating, anneal at 90°C for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer with a thickness of about 400nm.

(4) A 20 mg/ml PC ₆₁ BM chlorobenzene solution was uniformly coated on the perovskite layer by spin coating to form an electron transport layer with a thickness of about 40 nm.

(5) Apply 0.5 mg/ml BCP isopropanol solution evenly on the electron transport layer by spin coating to form a barrier layer with a thickness of about 8 nm.

(6) Preparation of the metal counter electrode: place the spin-coated multi-layer film device in the thermal evaporation equipment, and after the vacuum degree reaches 10 ^-5 Pa, thermal evaporation (that is, evaporation) deposits metal Au to prepare the metal counter electrode. Electrodes with a thickness of 100 nm.

The battery device was tested under the standard light condition of AM 1.5, and its energy conversion rate was 18.7%.

Example 5

The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ xH ₂ O, based on the content of different crystal water lead acetate (PbAc ₂ xH ₂ O) and methylamine iodine (MAI) in moles Dissolved in N,N-dimethylformamide (DMF) at a ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%, preferably x=2.8 H ₂ O, preferably with a mass fraction of 46%, in At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin coating. Metal Au is used as the metal electrode layer, and its specific preparation steps are as follows.

(1) A dense hole transport layer was obtained by spin-coating PEDOT:PSS aqueous solution on the cleaned UV-treated transparent ITO conductive glass substrate, and heat-treated at 140 ºC for 20 minutes to form a hole transport layer with a thickness of 50nm about.

(2) A 0.03 mg/ml 1-ethyl-3-methylimidazolium iodide DMF solution was uniformly coated on the hole transport layer by spin coating. And heat treatment at 130ºC for 15 minutes to form a modification layer of about 8nm.

(3) Dissolve lead acetate PbAc ₂ 2.8H ₂ O containing different crystal waters and methylamine iodide (MAI) in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 46 % perovskite solution, at low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin-coating technique, in which the substrate was preheated at 90ºC for 5min, Ca The titanium ore precursor solution was preheated at 75ºC for 5-10min. After spin-coating, anneal at 90°C for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer with a thickness of about 400nm.

(4) A 20 mg/ml PC ₆₁ BM chlorobenzene solution was uniformly coated on the perovskite layer by spin coating to form an electron transport layer with a thickness of about 40 nm.

(5) Apply 0.5 mg/ml BCP isopropanol solution evenly on the electron transport layer by spin coating to form a barrier layer with a thickness of about 8 nm.

(6) Preparation of the metal counter electrode: place the spin-coated multi-layer film device in the thermal evaporation equipment, and after the vacuum degree reaches 10 ^-5 Pa, thermal evaporation (that is, evaporation) deposits metal Au to prepare the metal counter electrode. Electrodes with a thickness of 100 nm.

The battery device was tested under the standard light condition of AM 1.5, and its energy conversion rate was 19.1%.

Example 6

The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ xH ₂ O, based on the content of different crystal water lead acetate (PbAc ₂ xH ₂ O) and methylamine iodine (MAI) in moles Dissolved in N,N-dimethylformamide (DMF) at a ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%, preferably x=2.8 H ₂ O, preferably with a mass fraction of 46%, in At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin coating. Metal Au is used as the metal electrode layer, and its specific preparation steps are as follows.

(1) A dense hole-transport layer was obtained by spin-coating PEDOT:PSS aqueous solution on the cleaned UV-treated transparent ITO-PEN flexible conductive substrate, and heat-treated at 140 ºC for 20min to form a hole-transport layer with a thickness of It is about 50nm.

(2) A 0.03 mg/ml 1-ethyl-3-methylimidazolium iodide DMF solution was uniformly coated on the hole transport layer by spin coating. And heat treatment at 130 ºC for 15 minutes to form a modification layer of about 8nm.

(3) Dissolve lead acetate PbAc ₂ 2.8H ₂ O containing different crystal waters and methylamine iodide (MAI) in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 46 % perovskite solution, at low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin-coating technique, in which the substrate was preheated at 90ºC for 5min, Ca The titanium ore precursor solution was preheated at 75ºC for 5-10min. After spin-coating, anneal at 90°C for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer with a thickness of about 400nm.

(4) A 20 mg/ml PC ₆₁ BM chlorobenzene solution was uniformly coated on the perovskite layer by spin coating to form an electron transport layer with a thickness of about 40 nm.

(5) Apply 0.5 mg/ml BCP isopropanol solution evenly on the electron transport layer by spin coating to form a barrier layer with a thickness of about 8 nm.

(6) Preparation of the metal counter electrode: place the spin-coated multi-layer film device in the thermal evaporation equipment, and after the vacuum degree reaches 10 ^-5 Pa, thermal evaporation (that is, evaporation) deposits metal Au to prepare the metal counter electrode. Electrodes with a thickness of 100 nm.

The energy conversion efficiency of the flexible battery device was 10.8% when tested under the standard light condition of AM 1.5.

Example 7

The perovskite layer is prepared by using a new perovskite material 3MAI: PbAc ₂ xH ₂ O, based on the content of different crystal water lead acetate (PbAc ₂ xH ₂ O) and methylamine iodine (MAI) in moles Dissolved in N,N-dimethylformamide (DMF) at a ratio of 1:3 to prepare a perovskite precursor solution with a mass fraction of 30%-50%, preferably x=2.8 H ₂ O, preferably with a mass fraction of 46%, in At low temperature (<100ºC), the perovskite layer is prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin coating. Metal Au is used as the metal electrode layer, and its specific preparation steps are as follows.

(1) A dense hole transport layer was obtained by spin-coating an ethanol solution of nickel oxalate hexahydrate (Ni(C ₂ O ₄ ) ₃ 6H ₂ O) on the cleaned UV-treated transparent FTO conductive glass substrate , and heat treatment at 140 ºC for 20 minutes to form a hole transport layer of about 50nm.

(2) A 0.03 mg/ml 1-ethyl-3-methylimidazolium iodide DMF solution was uniformly coated on the hole transport layer by spin coating. And heat treatment at 130 ºC for 15 minutes to form a modification layer of about 8nm.

(3) Dissolve lead acetate PbAc ₂ 2.8H ₂ O containing different crystal waters and methylamine iodide (MAI) in N,N-dimethylformamide (DMF) at a molar ratio of 1:3 to prepare a mass fraction of 46 % perovskite solution, at low temperature (<100ºC), the perovskite layer was prepared by rapid preheating of the substrate and heating of the perovskite precursor solution, i.e. heat-assisted spin-coating technique, in which the substrate was preheated at 90ºC for 5min, Ca The titanium ore precursor solution was preheated at 75ºC for 5-10min. After spin-coating, anneal at 90°C for 10 minutes, and finally obtain a high-quality perovskite light-absorbing layer with a thickness of about 400nm.

(4) A 20 mg/ml PC ₆₁ BM chlorobenzene solution was uniformly coated on the perovskite layer by spin coating to form an electron transport layer with a thickness of about 40 nm.

(5) Apply 0.5 mg/ml BCP isopropanol solution evenly on the electron transport layer by spin coating to form a barrier layer with a thickness of about 8 nm.

(6) Preparation of the metal counter electrode: place the spin-coated multi-layer film device in the thermal evaporation equipment, and after the vacuum degree reaches 10 ^-5 Pa, thermal evaporation (that is, evaporation) deposits metal Au to prepare the metal counter electrode. Electrodes with a thickness of 100 nm. .

The battery device was tested under the standard light condition of AM 1.5, and its energy conversion rate was 18.9%.

In the above-mentioned embodiments, the metal counter electrode is not limited to Au, but can also be Ag. For this new perovskite material PbAc ₂ ·xH ₂ O: 3CH ₃ NH ₂ I, the content of crystal water plays an important role in the quality of the perovskite film, so it is not only necessary to prepare the perovskite material Limited to crystal water content x=2.8, it can also be at least one of 0, 0.5, 1, 1.5, 2, 2.3, 2.5, 3, and the mass fraction is not limited to 46%, it can also be 30%, 35%, At least one of 40%, 48%, and 50%. Moreover, in the perovskite heat-assisted spin coating process (HASP), the substrate preheating temperature and the content of crystal water determine the quality of the perovskite film. Therefore, the substrate preheating temperature is not limited to 90ºC, but can also be 70ºC, 75ºC , at least one of 80ºC, 85ºC, 95ºC, 100ºC, the preheating temperature of the perovskite solution is not limited to 75ºC, it can be at least one of 60ºC, 65ºC, 70ºC, 80ºC. From the TGA analysis of the perovskite material PbAc ₂ ·xH ₂ O: 3CH ₃ NH ₂ I, it can be seen that there is a gradient peak between 72ºC-78ºC, indicating that the perovskite and crystal water form an intermediate, and this intermediate Bulk plays an important role in improving the quality of perovskite thin films.

Considering the above factors comprehensively, in the preparation process of the perovskite layer, the preferred crystal water content of the present invention is x=2.8, the rapid preheating temperature of the substrate is 90 ºC for 5 minutes, and the preheating temperature of the perovskite solution is 75 ºC.

Claims (6)

1. a kind of perovskite solar cell, it is characterised in that：It is transparent that the solar battery structure is followed successively by from top to bottom negative electrode Conductive substrates, hole transmission layer, Ionic Liquid Modified layer, perovskite light-absorption layer, electron transfer layer, barrier layer and metal are to electricity Pole.

2. perovskite solar cell according to claim 1, it is characterised in that：Negative electrode transparent conductive substrate includes FTO, The glass such as ITO, ITO-PEN, ITO-PET and flexible conducting substrate, hole transmission layer is PEDOT:PSS, NiO_X,.Ionic liquid is repaiied Decorations layer includes 1- ethyl-3-methylimidazole acetates, 1- ethyl -3- methylimidazolium chlorides, 1- ethyl -3- methy limidazoliums , 1- ethyl -3- methylpyridinium iodide imidazoles.The preparation of calcium titanium ore bed is using a kind of new perovskite material 3MAI： PbAc₂·xH₂Prepared by O (0≤x≤3), based on containing different crystallization water lead acetates（PbAc₂·xH₂O）With methylamine iodine (MAI) with Mol ratio 1:3 are dissolved in N,N-dimethylformamide（DMF）Mass fraction 30%-50% perovskite precursor solutions are configured to, low Under temperature（<100ºC）, it is prepared by heat auxiliary spin coating technique by the heating of the rapidly pre-warming to substrate and perovskite precursor solution Calcium titanium ore bed.Electron transfer layer is by PC₆₁The chlorobenzene solution of BM is prepared by spin coating, and barrier layer is mainly BCP (0.1- 0.6mg/ml is dissolved in isopropanol) spin-coating method acquisition, it is golden and silver-colored by thermal evaporation vacuum evaporation system as being mainly to electrode It is standby.

3. perovskite solar cell according to claim 1, it is characterised in that：Hole transmission layer 40-70nm, ionic liquid Body decorative layer 5-10nm, perovskite light-absorption layer 200-500nm, electron transfer layer 30-60nm, barrier layer BCP 5-10nm, metal To electrode 80-120nm.

4. perovskite solar cell according to claim 1, it is characterised in that：The preparation of calcium titanium ore bed is using a kind of New perovskite material 3MAI：PbAc₂·xH₂It is prepared by O, wherein 0≤x≤3, based on containing different crystallization water lead acetates （PbAc₂·xH₂O）With methylamine iodine (MAI) with mol ratio 1:3 are dissolved in N,N-dimethylformamide（DMF）It is configured to mass fraction 30%-50% perovskite precursor solutions, at low temperature（<100ºC）, it is molten by the rapidly pre-warming to substrate and perovskite precursor The heating of liquid is heat auxiliary spin coating technique（HASP）Calcium titanium ore bed is prepared, wherein substrate preheats 5min, body before perovskite in 90 C Liquid solution preheats 5-10min in 60-80 C.

5. the preparation method of the perovskite solar cell described in claim 1-4 any claim, it is characterised in that：Bag Include following steps：

(1) transparency electrode conductive layer is etched：One is etched on the transparent electrodes using the infrared laser that wavelength is 1000 nanometers Insulating tape so that the positive pole zone and negative regions being mutually not turned on is formed on electrode base board；

(2) preparation of hole transmission layer：1）The preparation of NiOx precursors：Accurately prepare nickel oxalate（Ni（C₂O₄）₃·6H₂O）Second Alcoholic solution 0.4mol/L, adds afterwards magneton 70 C sealing stirring 12 hours standby；PEDOT:The preparation of PSS precursors： PEDOT:The PSS aqueous solution (PVP Al 4083) is by being directly commercially available.After precursor solution is prepared, will carve before The transparent conductive substrate lost places 15min in ultraviolet process instrumentation, after substrate cooling, by the precursor solution for preparing Cover on transparent electrode substrate by the way that the method for spin coating is complete, the 20min of 140 C annealing afterwards forms hole transmission layer （40-70nm）；

（3）Ionic Liquid Modified layer：Afterwards spin quality concentration is the ionic liquid of 0.01-0.05mg/ml on hole transmission layer Body, 130 C annealing 15min, finally gives Ionic Liquid Modified layer (thickness 5-10nm)；

(4) preparation of perovskite light-absorption layer：First by the three acetate hydrate lead bought（99.99% Aladdin）Through in glove box In 100 C heating remove within 12 hours water, anhydrous acetic acid lead is obtained, afterwards by anhydrous acetic acid lead and three acetate hydrate lead by necessarily comparing Example is prepared, and finally gives the crystallization water lead acetate PbAc of different proportion₂·xH₂O(0≤x≤3).By containing different crystallization water acetic acid Lead PbAc₂·xH₂O (0≤x≤3) is with methylamine iodine (MAI) with mol ratio 1:3 are dissolved in N,N-dimethylformamide（DMF）It is configured to Mass fraction 30%-50% perovskite solution, at low temperature（<100ºC）, by the rapidly pre-warming to substrate and perovskite precursor The heating of solution is that heat auxiliary spin coating technique (HASP) prepares calcium titanium ore bed, and wherein substrate preheats 5min, calcium titanium in 90-100 C Ore deposit precursor solution preheats 5-10min in 60-80 C.90 C annealing 10min, finally obtains high-quality calcium titanium after spin coating is complete Ore deposit light-absorption layer（Thickness 200-500nm）；

(5) preparation of electron transfer layer：Electron transfer layer is by PC₆₁BM（20mg/ml is dissolved in chlorobenzene）It is prepared by spin-coating method (thickness 30-60nm)；

(6) preparation on barrier layer：Barrier layer is mainly BCP (0.1-0.6mg/ml is dissolved in isopropanol) and is obtained by spin-coating method (thickness 5-10nm)；

(7) evaporation metal is to electrode：Metal electrode is mainly Au and Ag, in vacuum<10^-5Pass through thermal evaporation vacuum under the conditions of pa Evaporation is prepared (thickness 80-120nm).

6. the preparation method of perovskite solar cell according to claim 5, it is characterised in that：Step 2,3,4,5,6 In operation carry out on spin coating instrument.