Application of upper interface modification material, perovskite solar cell and preparation method thereof

Abstract

The application provides application of an upper interface modification material, a perovskite solar cell and a preparation method thereof. In-situ reaction is performed on the surface of a perovskite layer of a trans perovskite solar cell by using the upper interface modification material to generate corresponding one-dimensional organic metal halides, namely, the upper interface modification material can form one-dimensional / three-dimensional heterojunctions on the upper interface of the trans perovskite solar cell. The one-dimensional / three-dimensional heterojunctions can effectively passivate surface defects of the trans perovskite solar cell, adjust surface energy level structures to make it more conducive to electron extraction, increase ion migration and charge accumulation, enhance surface hydrophobicity, stabilize the perovskite / fullerene interface and the like, so as to achieve the effects of enhancing the efficiency and stability of the trans perovskite solar cell.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and in particular relates to the application of upper interface modification materials, perovskite solar cells and their preparation methods. Background Technology

[0002] Organic-inorganic hybrid perovskite solar cells are widely recognized as a promising next-generation photovoltaic technology due to their excellent photovoltaic performance, tunable bandgap, outstanding defect tolerance, and low material cost. Among them, inverted pin perovskite solar cells have seen rapid development, with the highest efficiency reaching 27.3%. However, perovskites suffer from grain boundaries and various types of defects, especially at the upper interface. These defects not only induce nonradiative recombination but also reduce charge extraction efficiency, leading to charge accumulation and ion migration, thereby decreasing perovskite stability.

[0003] Surface modification is an effective strategy for mitigating interface defects and band mismatch. By introducing organic ligands, ionic liquids, or functionalized molecules, low-dimensional perovskite structures can be induced in situ on the surface of three-dimensional perovskites. Among these, two-dimensional passivation strategies have achieved significant progress in enhancing device stability, but some key challenges remain. The number of layers (n-value) in two-dimensional perovskites is difficult to control precisely, the distribution of the surface passivation layer is often non-uniform, and orientation control is very difficult. Furthermore, the energy levels of two-dimensional perovskites are typically slightly higher than those of three-dimensional perovskites, making them more suitable for nip structure devices. In contrast, one-dimensional perovskites have lower formation energies, more uniform crystal structures, and better energy level matching, which is beneficial for achieving efficient interface control and charge transport in inverted (pin) devices.

[0004] However, existing one-dimensional organic cations are mainly long-chain structures with poor conductivity, hindering efficient electron extraction at the electron transport layer interface and thus limiting device efficiency. Furthermore, these organic cations typically only possess Lewis acidity or Lewis basicity, making it difficult to achieve synergistic passivation of multiple defects, resulting in insufficient precision and repeatability in interface manipulation. More importantly, balancing high efficiency and stability under long-term operating conditions remains a major challenge in interface engineering. Summary of the Invention

[0005] To address the aforementioned issues, this application provides the application of interface modification materials, perovskite solar cells, and methods for their fabrication.

[0006] The first aspect of this application provides an application of an upper interface modification material in perovskite solar cells, wherein the structural formula of the upper interface modification material is as follows: R1 exists or does not exist; R2 exists or does not exist; within the quinary ring Represented as a double bond or a single bond; between A and R1 This indicates a double bond, a single bond, or the absence of a bond. When A is selected from carbon or nitrogen and has a +1 valence, and R1 is absent, there are double bonds between A and B, and between A and C. When A is selected from carbon or nitrogen and has a +1 valence, and R1 is present, and there is a single bond between A and R1, there is a double bond between A and B, and between A and C, and the other is a single bond. When A is selected from carbon or nitrogen and has a +1 valence, and R1 is present, and there is a double bond between A and R1, there are single bonds between A and B, and between A and C. When A is selected from nitrogen and is uncharged, and R1 is absent, there is a double bond between A and B, and between A and C, and the other is a single bond. When A is selected from nitrogen and... The structure is uncharged, R1 is present, and there are single bonds between A and R1, between A and B, and between A and C. Specifically, when A and B are single bonds, B is selected from oxygen, sulfur, and selenium; when A and B are double bonds, B is selected from carbon and nitrogen; when A and C are single bonds, C is selected from oxygen, sulfur, and selenium; when A and C are double bonds, C is selected from carbon and nitrogen; when B is selected from oxygen, sulfur, and selenium, and / or C is selected from oxygen, sulfur, and selenium, R2 and / or R3 are absent; when B is selected from carbon and nitrogen, and / or C is selected from carbon and nitrogen, R2 and / or R3 are present; when R1 is present and there is a single bond between A and R1, and A is selected from carbon, R1 is selected from hydrogen, alkyl, phenyl, NH2, and NH3. + NHNH2, NHNH3 + SCH3 , OC n H 2n+1 n is greater than or equal to 1; when R1 exists and there is a single bond between A and R1, and A is selected from nitrogen and has a positive valence of +1, R1 is selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, , When R1 is present and there is a single bond between A and R1, and A is selected from nitrogen and is uncharged, R1 is selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, and NH3. + , , When R1 is present and there is a double bond between A and R1, and A has a positive oxidation state of +1, R1 is selected from oxygen, sulfur, and NH; when R1 is present and there is a double bond between A and R1, and A is uncharged, R1 is selected from oxygen, sulfur, NH, and NH2. + When R2 and / or R3 are present, and A exhibits a positive valence of +1, R2 and / or R3 are selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, NHNH2, SCH3, , , OC n H 2n+1 n is greater than or equal to 1; when R2 and / or R3 are present and A is uncharged, R2 and / or R3 are selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, NH3. +NHNH2, NHNH3 + SCH3 , , , + NH2=C-NH2, OC n H 2n+1 n is greater than or equal to 1; X - Selected from Cl - ,Br - I - SCN - CN - F - ClO3 - PF6 - BF4 - NO3 - HSO3 - CH3COO - HCOO - CF3COO - ,

[0007] A second aspect of this application provides a perovskite solar cell, the perovskite solar cell comprising a perovskite layer containing the aforementioned upper interface modification material.

[0008] A third aspect of this application provides a method for preparing a perovskite solar cell, the method comprising: step 1, cleaning a conductive substrate to obtain a conductive substrate layer; step 2, spin-coating and annealing the cleaned conductive substrate with a spin-coating solution to obtain a hole transport layer; step 3, spin-coating a perovskite precursor solution to form a perovskite thin film to obtain a perovskite layer; step 4, dissolving the upper interface modification material in an organic solvent and spin-coating and annealing it to modify the surface of the perovskite layer with the upper interface modification material; and step 5, obtaining an electron transport layer and an electrode by thermal evaporation.

[0009] Compared with related technologies, the application of the upper interface modification material in perovskite solar cells in this application has the following advantages: the upper interface modification material can be used to generate corresponding one-dimensional organometal halide in situ on the surface of the perovskite layer of the inverted perovskite solar cell through in-situ reaction. That is, the upper interface modification material can form a one-dimensional / three-dimensional heterojunction on the upper interface of the inverted perovskite solar cell. This one-dimensional / three-dimensional heterojunction can effectively passivate the surface defects of the inverted perovskite solar cell, adjust the surface energy level structure to be more conducive to electron extraction, increase and reduce ion migration and charge accumulation, enhance surface hydrophobicity, and stabilize the perovskite / fullerene interface, thereby enhancing the efficiency and stability of the inverted perovskite solar cell. Attached Figure Description

[0010] Figure 1 The comparison between the control film of Comparative Example 1 and the target film of Example 1 (i.e., the comparison before and after HyImBr treatment): (a) and (b) are SEM images; (c) is a PXRD diffraction pattern; (d) is the integral intensity ratio of the lead iodide / (100) peak and the (100) / (111) peak. Figure 2 (a) is the KPFM image of the control film in Comparative Example 1; Figure 2 (b) is a KPFM image of the target thin film in Example 1; Figure 2 (c) shows the statistical distribution of CPD in the control film of Comparative Example 1 and the target film of Example 1; Figure 2 (d) Comparison of the control film, target film, and C in Example 1 60 Secondary electron cutoff peak and Fermi edge in the UPS spectrum of thin films; Figure 2 (e) Comparative Example 1 control film, Example 1 target film, and film simultaneously treated with HyImBr and PCBM / C 60 Energy level diagram of layer-modified perovskite thin films; Figure 3 XPS spectra of the control film of Comparative Example 1 and the target film of Example 1: (a) Pb 4f; (b) I 3d; (c) N 1s; Figure 4 The comparison is between the control film of Comparative Example 1 and the target film of Example 1: (a) and (d) are PL spectra; (b) and (e) are TRPL spectra; (c) is the data result of PL attenuation parameter measured from both sides of the film using 450 nm ultraviolet light; Figure 5 The Tas test energy distribution diagrams are for the control film of Comparative Example 1 and the target film of Example 1. Figure 6 The comparison is between the control device of Comparative Example 1 and the target device of Example 1: (a) is the JV curve of forward and reverse scanning; (b) is the EQE curve and the integral Jsc value; Figure 7 It is a statistical distribution of the device parameters of 20 control devices of Comparative Example 1 and 20 target devices of Example 1; Figure 8 The comparison is between the control device of Comparative Example 1 and the target device of Example 1: (a) is the voltage (Voc) versus light intensity curve; (b) is the FF loss; (c) is the transient photocurrent characteristic; (d) is the transient photovoltage characteristic; (e) is the electrochemical impedance spectroscopy, with the inset showing the equivalent circuit; (f) is the EIS fitting parameters; (g) is the JV curve in the dark state. Figure 9The comparison is between the control device of Comparative Example 1 and the target device of Example 1: (a) is the long-term stability of the normalized PCE of the unpackaged device stored in air at 30% relative humidity (RH) and 25°C; (b) is the long-term stability of the normalized PCE of the unpackaged device stored in air at 30% RH and 65°C; and (c) is the stable power output. Figure 10 (a) is the crystal structure of a one-dimensional (PCA)2PbI4 perovskite determined by single-crystal X-ray diffraction in Example 2; Figure 10 (b) is a top-view scanning electron microscope image of the control film of Comparative Example 2 and the target film of Example 2; Figure 10 (c) is a top-view atomic force microscope height diagram of the control film of Comparative Example 2 and the target film of Example 2; Figure 10 (d) are the powder X-ray diffraction patterns of the control film of Comparative Example 2 and the target film of Example 2; Figure 10 (e) shows the 2θ-sin²ψ plots and their linear fits obtained from grazing incidence X-ray diffraction measurements of the control film of Example 2 and the target film of Example 2; Figure 10 (f) is the control film of Comparative Example 2. Figure 10 (g) is a two-dimensional grazing-incidence wide-angle X-ray scattering pattern of the target thin film in Example 2 under different X-ray incident angles; Figure 11 Comparison of the control film of Comparative Example 2 and the target film of Example 2: (a) Nano-infrared spectrum; (b) Nano-infrared and FTIR spectra of site 0 in the control film and sites 1-4 in the target film; (c) Photoluminescence spectrum under 470 nm excitation light (incident from the glass side); (d) TRPL spectrum and corresponding fitted attenuation curve under 445 nm pulsed laser excitation; (e) Transient absorption spectrum under 470 nm excitation; (f) Photoluminescence spectrum under 520 nm excitation light (illuminance of 1 solar unit, from C 60 QFLS mapping under side incidence; Figure 12 (a) is the UPS energy spectrum of the control film of Comparative Example 2 and the target film of Example 2; Figure 12 (c) is an energy distribution diagram near the top interface of the target device in Example 2; Figure 12 (d) are KPFM images of the control film of Comparative Example 2, (e) the target film of Example 2, and (f) the corresponding CPD spectrum; Figure 13 (a) is a schematic diagram of the complete architecture of the target device; Figure 13(b) to (i) are comparisons of the control device in Example 2 and the target device in Example 2: (c) is the JV curve based on a 1.55 eV bandgap perovskite material; (d) is a device comparison based on a 1.66 eV bandgap perovskite material; (e) is the EQE curve and the integrated JSC value; (f) is the VOC-light intensity curve and its linear fitting results; (g) is the FF analysis results; (h) is the dark-state JV characteristic curve; (i) is the electrochemical impedance spectroscopy, with an inset showing the equivalent circuit. Figure 14 The following are the PCE evolutions of the unpackaged devices (Comparative Example 2 and Example 2): (a) stored in ambient air; (b) continuously heated to 65°C in a glove box; (c) under MPP tracking conditions; (d) top-view SEM images of the perovskite film before and after 24 hours of thermal aging at 65°C; (e) KPFM images of the perovskite film before and after 24 hours of thermal aging at 65°C. Figure 15 (a) is an atomic force microscope height diagram of the control film in Comparative Example 3; Figure 15 (b) is an atomic force microscope height diagram of the target thin film in Example 3; Figure 16 The comparison is between the control device of Comparative Example 3 and the target device of Example 3: (a) is the voltage versus light intensity curve; (b) is the electrochemical impedance spectroscopy, and the equivalent circuit is shown in the inset; (c) is the JV curve in the dark state; (d) is the device comparison based on the 1.66 eV bandgap perovskite material; (e) is the long-term stability of the normalized PCE of the unpackaged device stored in air at 30% relative humidity (RH) and 25°C. Detailed Implementation

[0011] The first aspect of this application provides an application of an upper interface modification material in perovskite solar cells. In the embodiments of this application, the upper interface modification material is used to generate a corresponding one-dimensional organometallic halide through an in-situ reaction on the perovskite surface. That is, the upper interface modification material can form a one-dimensional / three-dimensional heterojunction on the upper interface of the inverted perovskite solar cell. This one-dimensional / three-dimensional heterojunction can effectively passivate surface defects of the inverted perovskite solar cell, adjust the surface energy level structure to be more conducive to electron extraction, increase and reduce ion migration and charge accumulation, enhance surface hydrophobicity, and stabilize the perovskite / fullerene interface, thereby enhancing the efficiency and stability of the inverted perovskite solar cell.

[0012] A second aspect of this application provides a perovskite solar cell, comprising a perovskite layer containing an upper interface modification material. This application utilizes the upper interface modification material to modify the perovskite layer, thereby effectively improving the performance of the inverting solar cell.

[0013] Furthermore, in some embodiments, the perovskite layer has the general structural formula MNL3, where M is a metal cation and / or alkylammonium salt, N is a metal cation, and L is a halide anion; and N includes Pb. 2+ L includes I - This allows the perovskite layer to contain the component PbI2. Specifically, the perovskite layer may contain the component PbI2, so that the groups of the upper interface modification material can react with the component PbI2, thereby effectively reducing deep-level defects.

[0014] Furthermore, in some embodiments, M includes NH2CHNH2 + Cs + K + 、Rb + and / or CH3NH3 + N includes Cu 2+ Ni 2+ Co 2+ Cd 2+ 、Ge 2+ and / or Sn 2+ L includes Br - and / or Cl - In this application, the perovskite layer may contain other AX and BX2 components in addition to the constituent components. Although the composition of the perovskite layer varies in different embodiments, the upper interface modification materials in the embodiments of this application can all be used to generate one-dimensional organometal halide on the surface of the perovskite layer to effectively passivate defects and improve battery efficiency and performance.

[0015] Furthermore, this application is an inverted perovskite solar cell. Therefore, depending on the direction of the vapor deposition thickness, the perovskite solar cell of this application may sequentially include a conductive substrate layer, a hole transport layer, a perovskite layer, an electron transport layer, and a metal electrode.

[0016] The third aspect of this application provides a method for preparing a perovskite solar cell, the method comprising: step 1, cleaning a conductive substrate to obtain a conductive substrate layer; step 2, spin-coating and annealing the cleaned conductive substrate with a spin-coating solution to obtain a hole transport layer; step 3, spin-coating a perovskite precursor solution to form a perovskite thin film to obtain a perovskite layer; step 4, preparing an upper interface modification material into a first solution, and spin-coating and annealing it to modify the surface of the perovskite layer with the upper interface modification material; step 5, obtaining an electron transport layer and electrodes by thermal evaporation.

[0017] In this application, in step 4, the upper interface modification material is prepared into a first solution and then spin-coated and annealed to allow the upper interface modification material to form a one-dimensional / three-dimensional heterojunction on the surface of the perovskite layer, which can enhance the efficiency and stability of the inverted perovskite solar cell. It should be noted that steps 1 to 3, and step 5, are conventional manufacturing steps for perovskite solar cells, and those skilled in the art can make adaptive adjustments based on the actual process; these will not be elaborated upon here.

[0018] In step 4, the organic solvent includes at least one of isopropanol, toluene, chlorobenzene, chloroform, N,N-dimethylformamide, dimethyl sulfoxide, ethyl acetate, and diethyl ether.

[0019] Furthermore, in some embodiments, the upper interface modification material is dissolved in an organic solvent at a concentration of 0.1-2.0 mg / mL. For example, 0.1 mg / mL means that 0.1 mg of the upper interface modification material can be dissolved in 1 mL of organic solvent. Specific concentrations can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2 mg / mL, etc., to avoid excessively high or low concentrations of the upper interface modification material, ensuring effective reaction of the upper interface modification material on the perovskite layer surface.

[0020] Furthermore, in some embodiments, the spin coating speed in step 4 is 3000-6000 rpm, and the spin coating time is 30s-1min. Specifically, the spin coating speed can be 3000, 4000, 5000, 6000 rpm, etc., and the spin coating time can be 30s, 40s, 50s, 1min, etc., thereby ensuring that the upper interface modification material is uniformly covered on the perovskite layer.

[0021] Furthermore, in some embodiments, the annealing temperature in step 4 is 80-120°C, and the annealing time is 10-40 min. Specifically, the annealing temperature can be 80, 90, 100, 110, 120°C, etc., and the annealing time can be 10, 20, 30, 40 min, etc., so that the upper interface modification can fully and effectively react on the surface of the perovskite layer.

[0022] The following examples further illustrate this point.

[0023] Example 1 Step 1: The ITO glass substrate was cleaned for 15 minutes each in an ultrasonic bath using detergent, ultrapure water, ethanol, and isopropanol. The ITO substrate was dried with N2 and then subjected to UV ozone treatment for 15 minutes. The ITO substrate was transferred to an N2 glove box. Subsequently, SAM (0.5 mg / ml [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate dissolved in isopropanol) was spin-coated onto the substrate at 3000 rpm for 50 seconds, and annealed at 100°C for 10 minutes. Then, 1.6 M CsO... 05 (FA0. 95 MA0. 05 0. 95 Pb(I0). 95 Br0. 05 )3 Perovskite precursor solution dissolved in 1 ml of a mixed solvent of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) (V DMF V DMSO A 4:1 mixture of perovskite precursor and 9% excess PbI₂ was added. The perovskite precursor solution was spin-coated sequentially at 1000 rpm for 5 seconds and at 5000 rpm for 35 seconds. During the last 12 seconds, 150 μL of chlorobenzene was added dropwise as an antisolvent. The perovskite film was annealed at 100°C for 30 minutes to obtain a three-dimensional perovskite film.

[0024] Step 2: Dissolve 0.25 mg / mL 2-hydrazino-2-imidazoline hydrobromide (defined here as HyImBr) in a mixed solvent of isopropanol and chlorobenzene (VIPA / V chlorobenzene = 50:50), spin coat at 5000 rpm for 45 seconds, and anneal at 100°C for 25 minutes to modify a three-dimensional perovskite film with HyImBr.

[0025] Step 3: In a high vacuum (approximately 10...) -5 Under Torr conditions, 30 nm C was deposited on perovskite films via thermal evaporation. 60 Perovskite solar cell devices (which can be simply referred to as devices) can be obtained by using 8 nm BCP and 100 nm Ag.

[0026] In addition, this application also provides Comparative Example 1, which differs from Example 1 in that Comparative Example 1 does not include step two, that is, the perovskite layer in Comparative Example 1 does not include HyImBr. For ease of explanation, the perovskite thin film of Example 1 (treated with HyImBr) is the target thin film (represented as HyImBr in the figure), and the perovskite solar cell device of Example 1 is the target device (represented as HyImBr in the figure); the perovskite thin film of Comparative Example 1 (not treated with HyImBr) is the control thin film (represented as Control in the figure), and the perovskite solar cell device of Comparative Example 1 is the control device (represented as Control in the figure).

[0027] Example 1 of this application designs a multifunctional organic molecule—2-hydrazino-2-imidazoline hydrobromide (HyImBr)—as an upper interface modifier. HyImBr's structure features numerous functional groups that can act as both Lewis acids and Lewis bases, selectively passivating electron-rich and electron-deficient defects in perovskites. These functional groups can also form multiple hydrogen bonds with perovskite components, contributing to the formation of a thermodynamically stable low-dimensional phase. Furthermore, the reducing properties of the hydrazino group can effectively alleviate oxidation-related degradation, improving the stability of photoelectric conversion devices. In addition, HyImBr's compact molecular size and moderate polarity are expected to promote efficient charge extraction at the top interface.

[0028] The structural formula of HyImBr is as follows: .

[0029] like Figure 1 (a) and (b), using scanning electron microscopy to observe the target and control films, it was found that after HyImBr treatment, the perovskite film surface exhibited high grain smoothness and density. Furthermore, the lead iodide phase on the perovskite film surface was significantly reduced, and newly formed needle-like crystals mainly appeared at grain boundaries. Meanwhile, as... Figure 1 (c) The PXRD pattern of the target film shows a significant decrease in the intensity of the lead iodide peak, and a new diffraction signal peak appears at 2θ = 10.12 with a d-interval of 0.873 nm, indicating that lead iodide reacts with HyImBr to form a low-dimensional phase. On the other hand, as... Figure 1 (d) After HyImBr modification, the strength ratio of lead iodide / (100) decreased, while the strength ratio of (100) / (111) increased, indicating that the surface treatment achieved composition and orientation optimization that is beneficial to device performance.

[0030] To investigate the electronic properties of the perovskite film surface after HyImBr modification, this application used Kelvin probe force microscopy (KPFM) to detect the contact potential difference (CPD) of the film. Figure 2In (a) to (b), the average CPD values ​​of the control film and the target film are 453 mV and 286 mV, respectively, indicating an upward shift of the surface Fermi level. Furthermore, as... Figure 2 (c) The target film exhibits a more uniform CPD distribution throughout the film, indicating fewer defects and a more uniform distribution of HyImBr on the surface. Figure 2 (d) The energy levels of the control film and the modified surface (target film) were determined by ultraviolet photoelectron spectroscopy (UPS). Figure 2 (e) After treatment with HyImBr, the work function (WF) decreased from 4.55 eV to 4.36 eV, indicating n-type doping and band bending near the perovskite surface, which is beneficial for electron extraction. Furthermore, the conduction band minimum (CBM) decreased from -3.99 eV to -4.26 eV, and the valence band maximum (VBM) decreased from -5.55 eV to -5.82 eV, indicating improved electron transport efficiency and hole blocking performance.

[0031] like Figure 3 This application uses XPS to study the interaction between HyImBr and perovskite. It can be found that after HyImBr modification, the Pb 4f, I 3d and N 1s XPS peaks all shift to the direction of lower binding energy, which indicates that the overall electron density on the perovskite surface atoms increases.

[0032] like Figure 4 (a) and (b), this application further confirmed the effect of HyImBr treatment on carrier dynamics of perovskite thin films using steady-state photoluminescence (PL) and time-resolved photoluminescence (TRPL) techniques. The perovskite thin films treated with HyImBr exhibited significantly enhanced PL intensity, indicating that nonradiative recombination processes were effectively suppressed. Figure 4 (c) The corresponding TRPL decay curves were fitted using a double exponential function. The results showed that the average carrier lifetime of the control film was 127 ns, while that of the target film was 524 ns. This significant lifetime extension indicates that surface defects were effectively passivated, and non-radiative recombination within the target film was significantly reduced. Figure 4 (d) and (e), when PCBM and C were prepared on a control film 60 When the electron transport layer was formed, a significant PL quenching phenomenon was observed due to the nonradiative recombination process at the interface. However, the introduction of HyImBr alleviated this effect, resulting in a higher PL intensity for the target film compared to the control film. TRPL analysis also showed a significant increase in average lifetime from 28 ns to 105 ns.

[0033] like Figure 5This application characterizes the target device and the control device using thermal conductivity (Tas) spectra, revealing the energy distribution characteristics of the trapped states. The target film exhibits excellent defect density across the entire spectral range, particularly in the deep trap depth region. The reduction in trap density can be attributed to the excellent perovskite film quality, good interfacial contact properties, and outstanding defect passivation capability of the HyImBr material.

[0034] In addition, the JV curves of the reference device and the target device are as follows: Figure 6 As shown in (a), the control device exhibits a photoelectric conversion efficiency (PCE) of 23.51%, an open-circuit voltage (Voc) of 1.11 V, a fill factor (FF) of 82.81%, and a short-circuit current density (J) of 25.61 mA / cm². SC In comparison, the target device achieves a PCE of 26.11%, a Voc of 1.18 V, an FF of 85.27%, and a J of 25.91 mA / cm². SC To verify J SC The accuracy, such as Figure 6 (b) This application also obtained the external quantum efficiency (EQE) spectrum of the target device. The combined J of the control device and the target device... SC The deviations between the values ​​and the JV test results are all within 5%. Furthermore, to evaluate the repeatability of the device, such as... Figure 7 In this application, the photovoltaic parameters of 20 devices from Comparative Example 1 and Example 1 were analyzed respectively. The results show that the devices treated with HyImBr exhibit excellent reproducibility and minimal parameter fluctuations, which is attributed to the uniform and defect-free interface formed by surface reconstruction.

[0035] To further evaluate carrier transport and recombination mechanisms, such as Figure 8 (a) This application characterizes the variation of Voc value with light intensity. The ideality factor (n) of the control device and the target device are 1.49 and 1.17, respectively, indicating that the nonradiative recombination phenomenon is generally reduced. Figure 8 (b) FF analysis shows that the main reason for the FF enhancement lies in the suppression of non-radiative losses. For example... Figure 8 (c) and (d), this application further investigated the carrier dynamics in the intact device using transient photocurrent (TPC) and transient photovoltage (TPV) measurements. The average lifetime of TPC decay decreased from 3.87 μs to 2.20 μs, indicating a significant improvement in the separation efficiency of photogenerated carriers through the top interface. Simultaneously, the TPV lifetime significantly increased from 3.79 μs to 8.53 μs, indicating that nonradiative recombination processes were effectively suppressed. Figure 8In (e) and (f), the electrochemical impedance spectroscopy (EIS) spectra of both devices exhibit semicircular curves, and their equivalent circuits are shown in the inset. The composite resistance increases significantly from 543 Ω (Comparative Example 1) to 3807 Ω (Example 1), while the series resistance increases from 35.8 Ω to 126 Ω, reflecting the optimization of charge transport efficiency. Figure 8 (g) The dark JV characteristics of the target device show that its leakage current is lower, indicating that the shunt path is suppressed or that defect-induced dark current exists.

[0036] The device's operational stability was then evaluated according to the ISOS protocol. For example... Figure 9 (a) Both the unpackaged control device and the target device were stored in air (30% relative humidity) for 1100 hours. The control device maintained 72% of its initial efficiency, while the device treated with HyImBr (the target device) maintained 92% of its initial efficiency. Simultaneously, both sets of devices were continuously heated to 65°C in a nitrogen (N2) atmosphere. Figure 9 (b) The target device maintained 86% of its initial efficiency after 880 hours, while the control device's photoelectric conversion efficiency (PCE) dropped to 60% after 408 hours. Figure 9 (c) Steady-state power output was measured using maximum power point tracking (MPPT) technology. The results showed that the control device and the target device achieved steady-state photoelectric conversion efficiencies (PCE) of 22.96% and 25.72%, respectively, after 400 seconds. These results indicate that the target device has excellent environmental and thermal stability.

[0037] Example 2 Step 1: The ITO glass substrate was cleaned for 15 minutes each in an ultrasonic bath using detergent, ultrapure water, ethanol, and isopropanol. The ITO substrate was dried with N2 and then subjected to UV ozone treatment for 30 minutes. The ITO substrate was transferred to an N2 glove box. Subsequently, SAM (0.5 mg / ml [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate dissolved in isopropanol) was spin-coated onto the substrate at 3000 rpm for 50 seconds, and annealed at 100°C for 10 minutes. Then, 1.6 M CsO... 05 (FA0. 95 MA0. 05 0. 95 Pb(I0). 95 Br0. 05 )3 Perovskite precursor solution dissolved in 1 ml of a mixed solvent of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) (V DMF V DMSOA 4:1 ratio of perovskite precursor solution was prepared by spin-coating with 9% excess PbI₂. The perovskite precursor solution was then spin-coated sequentially at 1000 rpm for 10 seconds and at 5000 rpm for 30 seconds. During the last 10 seconds, 150 μL of chlorobenzene was added as an antisolvent. The perovskite film was annealed at 100°C for 30 minutes to obtain a three-dimensional perovskite film.

[0038] Step 2: PCACl and sodium hydroxide were mixed in a mixture of 300 mL CH2Cl2 and 80 mL H2O. After stirring at room temperature for two hours, the solvent was removed by rotary evaporation to obtain 13.23 mmol PCA, with a yield of 33%. PCAI was synthesized by neutralizing equimolar amounts of HI and PCA in an ice bath. After removing the solvent by rotary evaporation under reduced pressure, a white precipitate was collected. The product was ground, washed three times with diethyl ether, and vacuum dried overnight to obtain a white powder of PCAI in 98% yield. Next, 0.25 mg / mL 1H-pyrazole-1-carboxamide hydroiodide (defined herein as PCAI) was dissolved in isopropanol, spin-coated at 5000 rpm on the perovskite film obtained in Step 1 for 45 seconds, and annealed at 100°C for 10 minutes.

[0039] Step 3: In a high vacuum (approximately 10...) -5 Under Torr conditions, 30 nm C was deposited on perovskite films via thermal evaporation. 60 Perovskite solar cell devices (which can be simply referred to as devices) can be obtained by using 5 nm BCP and 100 nm Ag.

[0040] The structural formula of PCAI is as follows: .

[0041] In addition, this application also provides Comparative Example 2. The difference from Example 2 is that Comparative Example 2 does not include step two; that is, the perovskite layer in Comparative Example 2 does not include PCAI. For ease of explanation, the perovskite thin film of Example 2 (treated with PCAI) is the target thin film (represented as PCAI in the figure), and the perovskite solar cell device of Example 2 is the target device (represented as PCAI in the figure); the perovskite thin film of Comparative Example 2 (not treated with PCAI) is the control thin film (represented as Control in the figure), and the perovskite solar cell device of Comparative Example 2 is the control device (represented as Control in the figure).

[0042] In Example 2, the various functional groups contained in PCAI (including Lewis acid-type amidine groups and Lewis base-type pyrazole groups) are expected to passivate various defects at the top interface of PSC. Furthermore, the abundant hydrogen bonding sites and extended π-conjugated planes in PCAI are conducive to the formation of a stable 1D structure, rather than the formation of a competing 2D phase. The large π-planar structure may also enhance charge transport capabilities and affinity for C.60 The interaction between them facilitates the smooth progress of the electron extraction process at the interface.

[0043] PCAI synthesized a one-dimensional perovskite compound (PCA)2PbI4 on the perovskite surface via a simple cooling crystallization method. For example... Figure 10 (a) The crystal is formed by [PbI6] through edge-sharing. 4- The structure consists of a one-dimensional inorganic chain composed of octahedrons, surrounded by PCA. + A cation. Its crystal structure exhibits high symmetry; [PbI6] 4- Octahedron and PCA + Each cation possesses only one crystallographically independent site. In addition to hydrogen bonding between the amidine group and the inorganic framework (N3-H3···I1 and N4-H4···I1), the amidine group also forms hydrogen bonds with adjacent pyrazole units (N3-H3···N2), constructing a robust interlocking structure. These interactions shorten the one-dimensional interchain distances, resulting in a minimum Pb–Pb spacing of only 11.2 Å, which may be a key factor in the high formation energy and stability of this one-dimensional perovskite compound.

[0044] like Figure 10 (b) Scanning electron microscopy (SEM) images show a significant evolution in surface morphology from the control film to the target film. The target film exhibits a larger grain size (average grain size increased from 275 nm to 531 nm), while... Figure 10 (c) Atomic force microscopy (AFM) height images show that the root mean square roughness (Ra) decreased from 21.7 nm to 19.2 nm. A smoother surface should facilitate subsequent C... 60 More uniform deposition of the layers and improved efficiency of interfacial electron extraction. For example... Figure 10 (d) The PXRD pattern of the thin film shows that the intensity ratio of the (100) / (111) peaks increases significantly from the control group to the target group, indicating that the crystallographic orientation is improved, which is more beneficial to photoelectric properties. Figure 10 (e) The slope of the linear fitting of the 2θ-sin²ψ curve of the target thin film (-2.15×10⁻⁶). -4 The level was significantly lower than that of the control group (-8.67×10). -4 This confirms the relaxation of lattice strain during recrystallization.

[0045] The presence of a one-dimensional phase on the perovskite surface was also confirmed by PXRD and SEM. Figure 10 (b) SEM images show that rod-shaped one-dimensional crystals are mainly distributed at the grain boundaries of the expanded perovskite grains, and these crystals are expected to effectively passivate defect-rich areas. Figure 10(d) In the PXRD pattern of the target thin film, a low-angle diffraction peak appears at 8.5°, indicating the formation of a low-dimensional phase on the surface. The calculated corresponding d-interval is 10.3 Å, which matches the (10-1) crystal plane of the (PCA)₂PbI₄ single crystal (d-interval = 10.3 Å). Figure 10 (f) Grazing incidence wide-angle X-ray scattering (GIWAXS) is shown at q=8.84 nm. -1 and 9.89 nm -1 Diffraction signals appeared at these locations, attributed to the α phase of residual lead iodide and three-dimensional perovskite, respectively. For example... Figure 10 (g), after PCAI modification, q=8.84nm -1 The intensity of the lead iodide scattering signal is significantly reduced at q=5.99 nm. -1 The appearance of a new scattering ring indicates that lead iodide or perovskite reacted with PCAI to form a one-dimensional perovskite sample. The one-dimensional GIWAXS peak with a d-spacing of 10.5 Å is consistent with the PXRD results. Its stronger scattering intensity along the qz direction indicates that the (10⁻¹) plane of the one-dimensional crystal is in-plane oriented, suggesting that the one-dimensional inorganic chains are aligned parallel to the perovskite substrate. Notably, despite attempts at various surface modifications and single-crystal growth conditions, no evidence of a potential two-dimensional phase was observed. This suggests that the formation energy of the resulting 1D structure is significantly lower than that of the two-dimensional structure, fundamentally avoiding the compositional complexity problems common in two-dimensional / three-dimensional heterostructures.

[0046] like Figure 11 (a) The distribution of organic cations in specific nanoscale regions of the surface was localized using photoinduced force microscopy (PiFM). At 1564 cm⁻¹ -1 (PCA) + PiFM localization at the characteristic absorption wavenumber showed that the one-dimensional rod-like structure (site 1 on the target film) had a high signal intensity, confirming PCA. + It is abundant in one-dimensional (PCA)₂PbI₄ crystals. On the other hand, although the signal is weaker, uniformly distributed PCA was also detected in regions not covered by the one-dimensional rod-like structure (sites 2-4 on the target film). + Signal. Specifically, compared to the control film (site 0), the PiFM spectrum (nano-infrared spectrum) of site 1 is at 1626 cm⁻¹. -1 and 1694 cm -1 At 1409 cm -1 and 1564 cm -1 It was also observed that the PCA was attributable to + Additional absorption peaks from the C=C stretching vibration of the pyrazole ring. These characteristic absorption peaks are also present in the PiFM spectra of sites 2-4 on the target film, but with lower intensities. These results indicate that PCA+ The cations uniformly cover the entire perovskite surface outside the 1D crystal, thus providing comprehensive interfacial protection and defect passivation beyond the grain boundaries. Furthermore, compared to the Fourier transform infrared (FTIR) spectrum of the original PCAI powder, the C═N stretching vibration peaks on the perovskite surface show a significant shift, indicating that PCAI... + There is a strong interaction between it and perovskite.

[0047] This application employs steady-state photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurement techniques to study target and control films, aiming to investigate the influence of one-dimensional / three-dimensional heterostructures on the carrier dynamics of pristine perovskites. Figure 11 As shown in (c), the steady-state PL strength of the perovskite film increased by approximately 5 times after one-dimensional modification. Figure 11 (d) The TRPL decay curve can be fitted using a double exponential function. The short-lived component (τ1) associated with Shockley-Reed-Hall (SRH) nonradiative recombination of perovskite is extended from 5.6 ns to 7.0 ns after modification, but the amplitude is reduced; while the long-lived component (τ2) attributed to radiative recombination increases significantly from 0.51 µs to 1.0 µs, indicating that the carrier diffusion length is extended and the overall recombination rate is slowed down. This shows that the one-dimensional / three-dimensional heterostructure effectively passivates the defects on the perovskite surface.

[0048] In the deposition of C 60 After the electron transport layer, perovskite / C 60 Nonradiative recombination at the interface becomes the dominant process, which is the main VOC loss mechanism in inverted perovskite solar cells. 60 Compared to perovskite films, C was deposited 60 The perovskite thin film exhibits a significant photoluminescence quenching phenomenon, reducing the photoluminescence intensity by about an order of magnitude. However, as... Figure 11 (c) The introduction of one-dimensional / three-dimensional heterostructures significantly alleviated this quenching effect. For example... Figure 11 (d) For glass / perovskite (with / without PCAI) / C 60 TRPL analysis of the thin film again revealed two decay components: a short-lived component and a C-free component. 60 Similar to thin films, recombination is mediated by bulk defects; while the long-lived components in the tens of nanoseconds range are attributed to interfacial nonradiative recombination. The extension of both components leads to an increase in the average carrier lifetime from 49 nanoseconds to 59 nanoseconds after one-dimensional (1D) modification, indicating that deep interface defect states are effectively suppressed. Figure 11 As shown in (e), this application also includes ITO / 4PADCB / perovskite (with / without PCAI) / C 60Complementary transient absorption spectroscopy (TA) measurements were performed on the thin films. Both films exhibited a strong photoinduced bleaching (PIB) signal at 780 nm, corresponding to the ground-state bleaching of the perovskite upon excitation.

[0049] To correlate photocarrier dynamics with PSC device performance, this application utilizes glass / perovskite / C with / without 1D modification. 60 Quasi-Fermi level splitting (QFLS) imaging was performed on the thin films. Both films exhibited relatively uniform QFLS distributions, while the target film showed significantly stronger PL intensity and a higher QFLS value (increasing from 1.053 eV to 1.071 eV). Figure 11 As shown in (f), this enhanced QFLS helps minimize energy loss at the interface and achieves a higher Voc in the complete device.

[0050] Proper energy level alignment is another key factor in suppressing nonradiative recombination at the interface and achieving efficient charge extraction. For example... Figure 12 As shown in (a) to (c), UV photoelectron spectroscopy (UPS) measurements of the ITO / 4PADCB / perovskite (with / without PCAI) stacked structure indicate that the target film's conduction band minimum (CBM) and valence band maximum (VBM) are –3.98 eV and –5.53 eV, respectively, slightly lower than the corresponding values ​​of the control film (–3.90 eV and –5.45 eV). The Fermi levels of the control film and the target film were determined to be –4.46 eV and –4.09 eV, respectively. These results are consistent with... Figure 12 The Kelvin probe force microscopy (KPFM) measurements shown in (d) and (e) are consistent, with the modified film exhibiting a higher average contact potential difference (CPD). It is noteworthy that, as Figure 12 (f) The target film exhibits a more uniform CPD value throughout the entire film layer, thanks to the surface recrystallization process and the uniform PCA+ capping layer. The downward shift of the perovskite energy level reduces its interaction with C 60 The energy shift between LUMOs facilitates smoother electron transfer. Simultaneously, the reduced VBM forms an energy barrier, suppressing hole accumulation at the interface.

[0051] In addition, such as Figure 13 (a) is a structural diagram of the target device in Example 2. The current density-voltage (JV) characteristics of the device are as follows: Figure 13 As shown in (b) and (c), the control device exhibits a maximum power conversion efficiency (PCE) of 24.03% in reverse scan, an open-circuit voltage (VOC) of 1.133 V, and a short-circuit current density (JSC) of 25.72 mA cm⁻¹. -2The fill factor (FF) is 82.44%. In comparison, the target device exhibits a significantly improved PCE of 26.33%, along with a higher VOC (1.181 V) and a JSC of 26.20 mA cm⁻¹. -2 FF is 85.02%. For example... Figure 13 (e) The integrated current density measured by external quantum efficiency (EQE) spectroscopy is consistent with these results. The hysteresis index (HI) of the target device is 3.19%, significantly lower than the 6.70% of the control group, indicating suppressed ion migration and reduced charge accumulation during device operation. Figure 13 (d) After applying one-dimensional / three-dimensional heterostructures to wide-bandgap (1.66 eV) photoelectric conversion devices (PSCs), the photoelectric conversion efficiency (PCE) increased from 20.14% to 22.52%, which proves that the strategy is effective in various PSC systems.

[0052] like Figure 13 (f) To elucidate the potential factors leading to improved device performance, this application first extracted the ideality factor (nID) from light intensity-dependent VOC measurement data. The nID value of the control group device was 1.36, while that of the target device decreased to 1.19, indicating a significant suppression of the overall nonradiative recombination effect. When analyzing FF loss, nID was used to quantify the nonradiative recombination loss from the Shockley-Queisser (SQ) limit to the maximum achievable FF value (FFmax). The additional loss from FFmax to the measured FF value is attributed to charge transport loss, which is determined by the resistance of multiple channels in the device. Figure 13 As shown in (g), the improvement in FF in the target device is mainly due to the significant reduction in nonradiative recombination (which is also reflected in the substantial increase in VOC value), while the reduction in charge transport loss also plays a certain role.

[0053] like Figure 13 (h) The target device exhibits a lower dark current density in the low bias region, confirming that the 1D / 3D heterostructure improves shunt resistance and reduces leakage current. For example... Figure 13 (i) Electrochemical impedance spectroscopy (EIS) shows that both devices exhibit semi-circular curves, and their equivalent circuits are illustrated in the inset. The control device (fitted series resistance Rs = 27 Ω, composite resistance Rrec = 2.4 × 10⁻⁶) 4 Compared to the previous method (Ω), the target device's Rs is significantly reduced to 1Ω, while its Rrec is higher, reaching 3.3 × 10⁻⁶. 4 The significant reduction in Rs is likely due to the tight interfacial contact at the top interface and the excellent conductivity of the 1D / 3D heterostructure itself.

[0054] like Figure 14(a) This application also systematically evaluated the long-term operational stability of the complete device. Following the ISOS-D-1 aging protocol (ambient air, relative humidity 30%-40%), the unpackaged target device maintained over 90% of its initial efficiency after 1000 hours, significantly better than the control group (whose efficiency decreased to 53%). Under ISOS-D-2I aging conditions (nitrogen atmosphere, 65°C), as... Figure 14 (b) The target device retained 78% of its initial performance after 1000 hours, while the control group dropped to 57% after only 400 hours. Figure 14 (c) When subjected to maximum power point (MPP) tracking illumination tests for more than 600 hours under ISOS-L-1I aging conditions (nitrogen environment, 30-40°C), the target device maintained 80% of its initial efficiency, while the control group rapidly declined to 68% within the first 100 hours. These results clearly demonstrate the superior improvement in environmental stability, thermal stability, and optical stability exhibited by one-dimensional / three-dimensional heterostructures.

[0055] like Figure 14 (d) In this application, the control film and the target film were also aged at 65°C for 24 hours in an N2 atmosphere. SEM images showed that the aged control film exhibited obvious pinholes due to perovskite decomposition and the release of volatile substances, while the target film remained largely intact with minimal morphological changes. Figure 14 (e) The KPFM plot further shows that the average CPD value of the control group shifted significantly by 30 mV, while the target film showed only a small shift of 5 mV after aging.

[0056] This demonstrates that PCAI can achieve high-performance perovskite solar cells by constructing one-dimensional / three-dimensional heterostructures at the top interface. Structural and compositional characterization confirmed the formation of a pure-phase one-dimensional perovskite-like structure: crystal rods are preferentially located at defect-rich grain boundaries, while molecular PCAI uniformly covers the entire perovskite surface. This surface reconstruction, combined with PCAI's inherent defect passivation capability and one-dimensional phase characteristics, collectively forms a high-quality, defect-free top interface. More importantly, it clarifies that PCAI can suppress electrons from C... 60 Reverse transfer to perovskite—a key factor in interfacial nonradiative recombination. Molecular dynamics simulations show that PCAI enhances perovskite / C by acting as a molecular "binder." 60 The connection between them effectively suppresses C. 60The self-aggregation phenomenon is observed. Therefore, the PCAI-modified device significantly improved the photoelectric conversion efficiency from 24.03% to 26.33%, a figure among the highest reported efficiencies for perovskite solar cells based on one-dimensional / three-dimensional heterostructures. Furthermore, compared to the control device, the target device exhibited significantly improved operational stability under humidity, temperature, and light stress conditions.

[0057] Example 3 Step 1: The ITO glass substrate was cleaned for 15 minutes each in an ultrasonic bath using detergent, ultrapure water, ethanol, and isopropanol. The ITO substrate was dried with N2 and then subjected to UV ozone treatment for 20 minutes. The ITO substrate was transferred to an N2 glove box. Subsequently, SAM (0.5 mg / ml [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate dissolved in isopropanol) was spin-coated onto the substrate at 3000 rpm for 50 seconds, and annealed at 100°C for 15 minutes. Then, 1.6 M CsO... 05 (FA0. 95 MA0. 05 0. 95 Pb(I0). 95 Br0. 05 )3 Perovskite precursor solution dissolved in 1 ml of a mixed solvent of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) (V DMF V DMSO A 4:1 ratio of perovskite precursor solution was prepared by spin-coating with 9% excess PbI₂. The perovskite precursor solution was then spin-coated sequentially at 1000 rpm for 5 seconds and at 5000 rpm for 30 seconds. During the final 12 seconds, 150 μL of chlorobenzene was added as an antisolvent. The perovskite film was annealed at 100°C for 25 minutes to obtain a three-dimensional perovskite film.

[0058] Step 2: Dissolve 0.25 mg / mL 2-hydrazino-2-imidazoline hydrobromide (defined here as HyImBr) in a mixed solvent of isopropanol and chlorobenzene (VIPA / V chlorobenzene = 50:50), spin coat at 5000 rpm for 45 seconds, and anneal at 100°C for 25 minutes to modify a three-dimensional perovskite film with HyImBr.

[0059] Step 3: In a high vacuum (approximately 10...) -5 Under Torr conditions, 30 nm C was deposited on perovskite films via thermal evaporation. 60 Perovskite solar cell devices (which can be simply referred to as devices) can be obtained by using 5 nm BCP and 100 nm Ag.

[0060] The structural formula of 2MTzHI is: .

[0061] In addition, this application also provides Comparative Example 3, which differs from Example 3 in that Comparative Example 3 does not include step two, that is, the perovskite layer in Comparative Example 3 does not include 2MTzHI. For ease of explanation, the perovskite thin film of Example 3 (treated with 2MTzHI) is the target thin film (represented as w / 2MTzHI in the figure), and the perovskite solar cell device of Example 3 is the target device (represented as w / 2MTzHI in the figure); the perovskite thin film of Comparative Example 3 (not treated with 2MTzHI) is the control thin film (represented as Control in the figure), and the perovskite solar cell device of Comparative Example 3 is the control device (represented as Control in the figure).

[0062] In Example 3, 2MTzHI contains a thiazole ring and a thioether group, which can react with Pb. 2+ Coordination reduces deep-level defects; NH + It can form hydrogen bonds with halogens or organic cations, enhancing interfacial bonding and promoting charge transport. Therefore, Example 3 not only passivates surface defects and reduces non-radiative recombination, but also improves carrier transport capabilities.

[0063] like Figure 15 Atomic force microscopy (AFM) images showed that the root mean square roughness (Ra) decreased from 20.6 nm to 19.8 nm. A smoother surface should facilitate subsequent... 60 More uniform deposition of the layer and improved efficiency of interfacial electron extraction.

[0064] like Figure 16 (a) To further evaluate the carrier transport and recombination mechanism, this application characterized the variation of Voc value with light intensity. The ideality factor (n) of the control device and the target device are 1.59 and 1.18, respectively, indicating that the nonradiative recombination phenomenon is generally weakened. Additionally, as... Figure 16 (b) The electrochemical impedance spectroscopy (EIS) spectra of both devices exhibit semicircular curves, and their equivalent circuits are shown in the inset. The significant increase in recombination resistance reflects the optimization of charge transport efficiency. Figure 16 (c) The dark JV characteristics of the target device show that its leakage current is lower, indicating that the shunt path is suppressed or that defect-induced dark current exists. Figure 16 (d) Applying one-dimensional / three-dimensional heterostructures to wide-bandgap photoelectric conversion devices increases the photoelectric conversion efficiency from 24.12% to 25.31%, demonstrating the effectiveness of this strategy in various PSC systems. For example... Figure 16(e) The device's operational stability was evaluated according to the ISOS protocol. Both the unpackaged control device and the target device were stored in air (30% relative humidity) for 1100 hours. The control device maintained 76% of its initial efficiency, while the device treated with HyImBr (the target device) maintained 91% of its initial efficiency.

[0065] In other embodiments, the upper interface modification material may also be , , , , , , or etc.

[0066] It should be understood that the specific embodiments described in this application are merely illustrative of the invention and not intended to limit the invention. The descriptions of each embodiment have their own emphasis; for parts not detailed in a particular embodiment, please refer to the relevant descriptions of other embodiments.

Claims

1. The application of an upper interface modification material in perovskite solar cells, characterized in that, The structural formula of the upper interface modification material is: Where R1 exists or does not exist; R2 exists or does not exist; within the quinary ring Represented as a double bond or a single bond; between A and R1 This indicates a double bond, a single bond, or that the bond does not exist. When A is selected from carbon or A is selected from nitrogen and has a positive valence of 1, and R1 does not exist, there are double bonds between A and B, and between A and C; When A is selected from carbon or A is selected from nitrogen and has a positive valence of 1, R1 exists, and there is a single bond between A and R1, either the bond between A and B or the bond between A and C is a double bond and the other is a single bond; When A is selected from carbon or A is selected from nitrogen and has a positive valence of 1, R1 is present, and there is a double bond between A and R1, there are single bonds between A and B, and between A and C. When A is selected from nitrogen and is uncharged, and R1 is absent, either A and B, or A and C, is a double bond and the other is a single bond; When A is selected from nitrogen and is uncharged, R1 exists, and there are single bonds between A and R1, between A and B, and between A and C; in, When there is a single bond between A and B, B is selected from oxygen, sulfur, and selenium; when there is a double bond between A and B, B is selected from carbon and nitrogen. When there is a single bond between A and C, C is selected from oxygen, sulfur, and selenium; when there is a double bond between A and C, C is selected from carbon and nitrogen. When B is selected from oxygen, sulfur, and selenium, and / or C is selected from oxygen, sulfur, and selenium, R2 and / or R3 do not exist; When B is selected from carbon and nitrogen, and / or C is selected from carbon and nitrogen, R2 and / or R3 are present; When R1 is present and there is a single bond between A and R1, and A is selected from carbon, R1 is selected from hydrogen, alkyl, phenyl, NH2, and NH3. + NHNH2, NHNH3 + SCH3 , OC n H 2n+1 n is greater than or equal to 1; When R1 is present and there is a single bond between A and R1, and A is selected from nitrogen and has a +1 oxidation state, R1 is selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, , ; When R1 is present and there is a single bond between A and R1, and A is selected from nitrogen and is uncharged, R1 is selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, and NH3. + , , ; When R1 is present and there is a double bond between A and R1, and A has a positive valence of +1, R1 is selected from oxygen, sulfur, and NH; When R1 is present and there is a double bond between A and R1, and A is uncharged, R1 is selected from oxygen, sulfur, NH, and NH2. + ; When R2 and / or R3 are present, and A exhibits a positive valence of +1, R2 and / or R3 are selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, NHNH2, SCH3, , , OC n H 2n+1 n is greater than or equal to 1; When R2 and / or R3 are present and A is uncharged, R2 and / or R3 are selected from hydrogen, fluorine, chlorine, bromine, iodine, alkyl, phenyl, NH2, and NH3. + NHNH2, NHNH3 + SCH3 , , , + NH2=C-NH2, OC n H 2n+1 n is greater than or equal to 1; X - Selected from Cl - ,Br - I - SCN - CN - F - ClO3 - PF6 - BF4 - NO3 - HSO3 - CH3COO - HCOO - CF3COO - , .

2. A perovskite solar cell, characterized in that, The perovskite solar cell includes a perovskite layer containing the upper interface modification material.

3. The perovskite solar cell according to claim 2, characterized in that, The perovskite layer has the general structural formula MNL3, where M is a metal cation and / or alkylammonium salt, N is a metal cation, and L is a halide anion; and N includes Pb. 2+ The L includes I - This is to ensure that the perovskite layer contains the component PbI2.

4. The perovskite solar cell according to claim 3, characterized in that, The M includes NH2CHNH2 + Cs + K + 、Rb + and / or CH3NH3 + The N includes Cu 2+ Ni 2+ Co 2+ Cd 2+ 、Ge 2+ and / or Sn 2+ The L includes Br - and / or Cl - .

5. The perovskite solar cell according to claim 2, characterized in that, The perovskite solar cell comprises a conductive substrate layer, a hole transport layer, the perovskite layer, an electron transport layer, and a metal electrode stacked sequentially.

6. A method for preparing a perovskite solar cell as described in any one of claims 2 to 5, characterized in that, The preparation method includes: Step 1: Clean the conductive substrate to obtain the conductive substrate layer; Step 2: Spin-coating and annealing the cleaned conductive substrate with spin coating solution to obtain the hole transport layer; Step 3: Spin-coat the perovskite precursor solution to form a perovskite thin film, thus obtaining a perovskite layer; Step 4: Dissolve the upper interface modification material in an organic solvent, and spin-coat and anneal it to modify the surface of the perovskite layer with the upper interface modification material. Step 5: Obtain the electron transport layer and electrodes by thermal evaporation.

7. The preparation method according to claim 6, characterized in that, The organic solvent includes at least one of isopropanol, toluene, chlorobenzene, chloroform, N,N-dimethylformamide, dimethyl sulfoxide, ethyl acetate, and diethyl ether.

8. The preparation method according to claim 7, characterized in that, Step 4 involves dissolving the upper interface modification material in an organic solvent, specifically by dissolving the upper interface modification material in an organic solvent at a concentration of 0.1-2.0 mg / mL.

9. The preparation method according to claim 7, characterized in that, In step 4, the spin coating speed is 3000-6000 rpm and the spin coating time is 30s-1min.

10. The preparation method according to claim 6, characterized in that, In step 4, the annealing temperature is 80-120℃ and the annealing time is 10-40 minutes.

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