Perovskite optoelectronic device interface modification method based on halogenated benzene alkyl amine molecules

Abstract

The application provides a perovskite photoelectric device interface modification method based on a halogenated benzene alkyl amine molecule. After an interface modification layer based on a halogenated benzene ethylamine molecule is introduced between a perovskite light-absorbing layer and a hole transport layer in a perovskite solar cell, interface defects are effectively passivated, defect state induced non-radiative recombination is weakened, radiative recombination is enhanced, the open circuit voltage and photoelectric conversion efficiency of the perovskite solar cell device are significantly improved, and the stability of the device is also significantly improved.

Description

Technical Field

[0001] This application relates to the field of perovskite optoelectronic device technology, and in particular to a method for modifying the interface of perovskite optoelectronic devices based on halophenylalkylamine molecules. Background Technology

[0002] Organic-inorganic metal halide perovskites are an emerging semiconductor material with advantages such as high light absorption coefficient, high defect tolerance, and tunable bandgap. Perovskite optoelectronic devices based on this semiconductor material, such as solar cells, light-emitting diodes (LEDs), and photodetectors, have become a research hotspot in academia in recent years. Perovskite solar cells, which utilize perovskite thin films as the light-absorbing layer, represent a promising solution in the photovoltaic field. Perovskite LEDs and photodetectors also have broad application prospects in displays, optical communications, and flexible devices.

[0003] Perovskite optoelectronic devices typically employ a multilayer thin-film structure fabricated using solution methods. Taking perovskite solar cells as an example, a polycrystalline perovskite thin film prepared using a solution method serves as the light-absorbing layer. After absorbing photons, electron-hole pairs are generated, which are then extracted and conducted to the electrodes and external circuitry via electron and hole transport layers. Through appropriate composition control, morphology optimization, and structural optimization, the certified photoelectric conversion efficiency of perovskite solar cells has reached 25.5%. However, there is still a gap between the theoretical and practical photoelectric conversion efficiency, and its stability is insufficient to meet the lifetime requirements of practical applications.

[0004] Defect states at the surface / interface of perovskite optoelectronic devices have always been a significant factor affecting their performance. Solution-prepared polycrystalline perovskite films often exhibit numerous surface defects. These defects not only induce nonradiative recombination, a major source of energy loss, but also induce degradation of the perovskite film, thus limiting the photoelectric performance and stability of perovskite optoelectronic devices. Therefore, effective defect passivation measures are needed to suppress defect states and energy losses at the surface and interface of perovskite optoelectronic devices, which is crucial for improving their performance and lifetime. Summary of the Invention

[0005] This application aims to provide an interface modification method for perovskite optoelectronic devices to effectively passivate defect states at the interface of perovskite optoelectronic devices, thereby improving the optoelectronic performance and stability of the devices.

[0006] Therefore, one embodiment of this application proposes an interface modification method for perovskite optoelectronic devices based on halophenylalkylamine molecules, which introduces an interface modification layer based on halophenylalkylamine molecules between the perovskite light-absorbing layer and the hole transport layer, that is, a halophenylalkylamine molecule thin film is prepared on the surface of the perovskite light-absorbing layer, and a hole transport layer is prepared on the surface of the halophenylalkylamine molecule thin film.

[0007] In some embodiments, the structural formula of the halophenylalkylamine molecule is:

[0008]

[0009] Wherein: substituents R1, R2, R3, R4, and R5 are any one of hydrogen, alkyl, cyano, trifluoromethyl, iodine, bromine, and chlorine, and at least one is a halogen atom; the substitution positions can be combined arbitrarily; X - It is an anion.

[0010] In some embodiments, alkylamine C n H 2n -NH3 + It is any one of methylamine, ethylamine, propylamine, and butylamine.

[0011] In some embodiments, anion X - Including but not limited to iodide ions, bromide ions, chloride ions, sulfate ions, tetrafluoroborate ions, thiocyanate ions, formate ions, acetate ions, trifluoromethanesulfonate ions, or trifluoroacetate ions.

[0012] In some embodiments, up to three of the substituents R1, R2, R3, R4, and R5 are halogen atoms of the same or different types.

[0013] In some embodiments, halogenated phenylalkylamines do not include 2-trifluoromethylphenethylamine hydroiodide, 3-trifluoromethylphenethylamine hydroiodide, 4-trifluoromethylphenethylamine hydroiodide, or 3-chlorobenzylamine hydroiodide.

[0014] In some embodiments, the halophenylalkylamine solution required for the interface modification layer is prepared by a solution method.

[0015] In some embodiments, the method for preparing the interface modification layer is as follows: the prepared halophenylalkylamine solution is attached to the surface of the perovskite light-absorbing layer by means including but not limited to spin coating, blade coating or vapor deposition.

[0016] In some embodiments, the halophenylalkylamine is 2-bromophenylethylamine hydroiodate, and the preparation method is as follows: 2-bromophenylethylamine hydroiodate is dissolved in isopropanol to obtain a 2-bromophenylethylamine hydroiodate solution, and the 2-bromophenylethylamine hydroiodate solution is spin-coated onto the surface of a perovskite light-absorbing layer film to obtain a 2-bromophenylethylamine hydroiodate interface modification layer film.

[0017] Another embodiment of this application proposes an application of the above-described modification method in the fabrication of perovskite optoelectronic devices, including but not limited to perovskite solar cells, light-emitting diodes, or photodetectors.

[0018] Compared with existing technologies, this invention has the following characteristics: By introducing an interface modification layer based on halophenylethylamine molecules between the perovskite light-absorbing layer and the hole transport layer in a perovskite solar cell, interface defects are effectively passivated, defect-state-induced nonradiative recombination is weakened, and radiative recombination is enhanced. Therefore, the open-circuit voltage and photoelectric conversion efficiency of the perovskite solar cell device are significantly improved. Simultaneously, the device stability is also significantly improved.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings.

[0021] in:

[0022] Figure 1 A schematic diagram of the basic perovskite solar cell device without an interface modification layer.

[0023] Figure 2 This is a schematic diagram of the basic perovskite solar cell device after the introduction of the interface modification layer in the embodiments of this application.

[0024] Figure 3 This is a comparison chart of the JV curves of the best-performing perovskite solar cells in Example 1 and Comparative Example 1.

[0025] Figure 4 This is a comparison chart of the maximum power point output tracking of perovskite solar cells in Example 1 and Comparative Example 1;

[0026] Figure 5 This is a comparison of the photoluminescence (PL) spectra of the perovskite light-absorbing layer films of Example 1 and Comparative Example 1. Detailed Implementation

[0027] The embodiments of this application are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0028] The following is a reference appendix. Figure 1-5 This application describes an interface modification method for perovskite optoelectronic devices based on halophenylalkylamine molecules.

[0029] This application proposes an interface modification method for perovskite optoelectronic devices based on halophenylalkylamine molecules. An interface modification layer based on halophenylalkylamine molecules is introduced between the perovskite light-absorbing layer and the hole transport layer. Specifically, a halophenylalkylamine molecule thin film is prepared on the surface of the perovskite light-absorbing layer, and a hole transport layer is prepared on the surface of the halophenylalkylamine molecule thin film. Figure 1-2 As shown.

[0030] As the main application of this invention—perovskite optoelectronic devices—perovskite solar cells are used as an example. Their structure, from bottom to top, according to the order of thin film deposition, consists of a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, an interface modification layer, a hole transport layer, and a counter electrode. The basic fabrication process is as follows:

[0031] Step 1: Etching and cleaning of the conductive substrate.

[0032] Step 2: Prepare the electron transport layer: Prepare a SnO2 electron transport layer on the surface of a conductive substrate and anneal it.

[0033] Step 3: Preparation of the perovskite light-absorbing layer: A (FA) layer is prepared on the electron transport layer. x MA 1-x PbI3 layer, followed by annealing.

[0034] Step 4: Prepare an interface modification layer: Prepare a halophenylethylamine molecular film on the surface of the perovskite light-absorbing layer.

[0035] Step 5: Prepare hole transport layer: Prepare spiro-OMeTAD thin film on the interface modification layer.

[0036] Step 6: Prepare the counter electrode: Deposit the counter electrode material on the hole transport layer using methods such as vacuum evaporation and magnetron sputtering.

[0037] In some embodiments, the structural formula of the halophenylalkylamine molecule is:

[0038]

[0039] in:

[0040] 1. Alkylamines substituted on the benzene ring (C) n H 2n -NH3+ It is any one of methylamine, ethylamine, propylamine, and butylamine.

[0041] 2. The substituents R1, R2, R3, R4, and R5 on the benzene ring are hydrogen (H) and alkyl (C) groups. n H 2n+1 The halogen atom can be any one of the following: cyano (CN), trifluoromethyl (CF3), iodine (I), bromine (Br), and chlorine (Cl), with at least one being a halogen atom: I, Br, or Cl. The halogen substitution on the benzene ring can be up to three halogen atoms of the same or different types. The five substitution positions can be combined arbitrarily.

[0042] 3. Anion X - It can be any type of anion, including but not limited to iodide ions (I₂). - ), bromide ion (Br) - ), chloride ions (Cl - sulfate ions (SO4) 2- ), tetrafluoroborate ion (BF4) - ), thiocyanate ion (SCN) - Formate ion (HCOO) - Acetate ion (CH3COO) - ), trifluoromethanesulfonate ions (CF3SO3) - ) or trifluoroacetate ion (CF3COO - )wait.

[0043] 4. 2-Trifluoromethylphenylethylamine hydroiodide (2-CF3PEAI), 3-trifluoromethylphenylethylamine hydroiodide (3-CF3PEAI), 4-trifluoromethylphenylethylamine hydroiodide (4-CF3PEAI), and 3-chlorophenylmethylamine hydroiodide (3-ClPBAI) are not included.

[0044] In some embodiments, the halophenylalkylamine solution required for the interface modification layer is prepared by a solution method.

[0045] In some embodiments, the method for preparing the interface modification layer is as follows: the prepared halophenylalkylamine solution is attached to the surface of the perovskite light-absorbing layer by means including but not limited to spin coating, blade coating or vapor deposition.

[0046] In some embodiments, the halophenylalkylamine is 2-bromophenylethylamine hydroiodate, and the preparation method is as follows: 2-bromophenylethylamine hydroiodate is dissolved in isopropanol to obtain a 2-bromophenylethylamine hydroiodate solution, and the 2-bromophenylethylamine hydroiodate solution is spin-coated onto the surface of a perovskite light-absorbing layer film to obtain a 2-bromophenylethylamine hydroiodate interface modification layer film.

[0047] Another embodiment of this application proposes an application of the above-described modification method in the fabrication of perovskite optoelectronic devices, including but not limited to perovskite solar cells, light-emitting diodes, or photodetectors.

[0048] The following detailed description of this case will be provided through specific embodiments:

[0049] Example 1

[0050] Step 1: Etching and cleaning of the conductive substrate.

[0051] ITO conductive glass substrate is used. First, a pre-designed pattern is etched on the conductive surface of the conductive glass using laser etching to distinguish the positive and negative electrodes of the solar cell. The conductive glass is then cleaned by immersing it in solvents such as detergent, deionized water, ethanol, and isopropanol in sequence, followed by ultrasonic cleaning. Finally, the surface of the ITO conductive glass is treated with ultraviolet ozone.

[0052] Step 2: Prepare the electron transport layer.

[0053] Tin oxide (SnO2) electron transport layer films were prepared using a solution method. First, a 15% (w / w) SnO2 colloidal aqueous solution was diluted with deionized water at a volume ratio of 3–6:1. Then, the diluted SnO2 colloidal aqueous solution was spin-coated onto a transparent electrode layer of ITO conductive glass. Finally, the spin-coated sample was annealed on a hot plate to obtain the SnO2 thin film as the electron transport layer.

[0054] Step 3: Prepare the perovskite light-absorbing layer.

[0055] Two-step solution preparation (FA) x MA 1-x PbI3 perovskite light-absorbing layer film.

[0056] First, prepare the two-step precursor solution. Dissolve lead iodide (PbI2) powder in a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio 4–9:1) to obtain a 1.5 M lead iodide precursor solution; dissolve iodomidine (CH(NH2)2I), iodomethylamine (CH3NH3I), and chloromethylamine (CH3NH3Cl) powders in isopropanol (IPA) to obtain a 0.7 M amine salt precursor solution.

[0057] Then, a perovskite light-absorbing layer film was prepared. First, a lead iodide precursor solution was spin-coated onto a SnO2 electron transport layer substrate. After spin-coating, the substrate was annealed at 70 degrees Celsius to obtain a lead iodide film. Then, an amine salt precursor solution was spin-coated onto the lead iodide film. After spin-coating, the substrate was annealed again to obtain the perovskite light-absorbing layer film.

[0058] Step 4: Prepare the interface modification layer.

[0059] A 2-bromophenylethylamine hydroiodate (2-BrPEAI) interface-modified layer was prepared by solution method. 2-BrPEAI was dissolved in isopropanol (IPA) to obtain a 2-BrPEAI solution. The 2-BrPEAI solution was spin-coated onto the surface of a perovskite light-absorbing layer film to obtain the 2-BrPEAI interface-modified layer film.

[0060] The molecular structure of 2-bromophenylethylamine hydroiodide (2-BrPEAI) is as follows:

[0061]

[0062] Step 5: Prepare the hole transport layer.

[0063] A solution-based method was used to prepare the spiro-OMeTAD hole transport layer. Spiro-OMeTAD hole transport material powder was dissolved in chlorobenzene (CB) to obtain a hole transport layer solution. This solution was then spin-coated onto a 2-BrPEAI film to obtain the spiro-OMeTAD hole transport layer film.

[0064] Step 6: Prepare the counter electrode.

[0065] Silver (Ag) electrodes were prepared by vapor deposition. A molybdenum oxide (MoO3) film and a silver (Ag) electrode were sequentially vapor-deposited onto the spiro-OMeTAD hole transport layer film to obtain a complete perovskite solar cell device.

[0066] Comparative Example 1:

[0067] Compared with the above embodiments, the steps do not include the preparation of the interface modification layer in step 4. After step 3, steps 5 and 6 are performed directly, that is, the hole transport layer is directly prepared on the perovskite light-absorbing layer.

[0068] Comparison results of Example 1 and Comparative Example 1:

[0069] In Example 1, by introducing an interface modification layer based on halophenylethylamine molecules between the perovskite light-absorbing layer and the hole transport layer in a perovskite solar cell, the interface defects are effectively passivated, the defect-state-induced nonradiative recombination is weakened, and the radiative recombination is enhanced (e.g., ...). Figure 5 As shown), therefore, the open-circuit voltage and photoelectric conversion efficiency of perovskite solar cell devices are significantly improved (e.g. Figure 3 As shown). At the same time, the device stability is also significantly improved (e.g. Figure 4 (As shown).

[0070] Furthermore, the preparation process of the interface modification layer based on this type of material, such as the preparation method (spin coating, blade coating, vapor deposition, etc.) and process parameters (concentration, rotation speed, annealing conditions, duration, etc.), can be any feasible alternative and combination. Except for the specific steps and parameters described in the examples, they can all be replaced by other equivalent or similar methods to achieve the interface modification layer based on halophenylethylamine molecules in this invention.

[0071] The perovskite solar cell, the subject of this invention, can have its device structure (formal inversion, location of the interface modification layer), material selection (different electron transport materials, perovskite composition, hole transport materials, etc.), preparation method (solution method, vapor deposition method, etc.), and process parameters (concentration, rotation speed, annealing conditions, duration, etc.) substituted and combined in any feasible manner. Except for the specific steps and parameters described in the embodiments, all can be replaced by other equivalent or similar methods to achieve a perovskite solar cell device to which this invention can be applied.

[0072] The application of this interface modification scheme is not limited to the perovskite solar cells in the embodiments, but can also be applied to other optoelectronic devices based on perovskite materials, such as light-emitting diodes (LEDs) and photodetectors.

[0073] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0074] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for modifying the interface of perovskite optoelectronic devices based on halophenylalkylamine molecules, characterized in that, An interface modification layer based on halobenzylamine molecules is introduced between the perovskite light-absorbing layer and the hole transport layer. Specifically, a halobenzylamine molecule thin film is prepared on the surface of the perovskite light-absorbing layer, and a hole transport layer is prepared on the surface of the halobenzylamine molecule thin film. The structural formula of the halophenylalkylamine molecule is: Wherein: substituents R1, R2, R3, R4, and R5 are any one of alkyl, cyano, trifluoromethyl, iodine, bromine, and chlorine, and at least one of them is a halogen atom, and the substitution positions can be combined arbitrarily; Alkylamine C n H 2n -NH3 + It is any one of methylamine, ethylamine, propylamine, and butylamine; Anion X - This includes sulfate ions, tetrafluoroborate ions, thiocyanate ions, formate ions, acetate ions, trifluoromethanesulfonate ions, or trifluoroacetate ions.

2. The modification method according to claim 1, characterized in that, The substituent groups R1, R2, R3, R4, and R5 can contain up to three halogen atoms of the same or different types.

3. The modification method according to claim 1, characterized in that, Halogenated benzylamines do not include 2-trifluoromethylphenethylamine hydroiodide, 3-trifluoromethylphenethylamine hydroiodide, 4-trifluoromethylphenethylamine hydroiodide or 3-chlorobenzylamine hydroiodide.

4. The modification method according to claim 1, characterized in that, The halophenylalkylamine solution required for the interface modification layer is prepared by a solution method.

5. The modification method according to claim 4, characterized in that, The interface modification layer is prepared by means of the following: the prepared halophenylalkylamine solution is attached to the surface of the perovskite light-absorbing layer by spin coating, blade coating or vapor deposition.

6. The modification method according to claim 1, characterized in that, The halophenylalkylamine is 2-bromophenylethylamine hydroiodate, and the preparation method is as follows: 2-bromophenylethylamine hydroiodate is dissolved in isopropanol to obtain a 2-bromophenylethylamine hydroiodate solution, and the 2-bromophenylethylamine hydroiodate solution is spin-coated onto the surface of the perovskite light-absorbing layer film to obtain a 2-bromophenylethylamine hydroiodate interface modification layer film.

7. The use of the modification method according to any one of claims 1-6, characterized in that, It is used in the fabrication of perovskite optoelectronic devices, including perovskite solar cells, light-emitting diodes, or photodetectors.

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