Cu-doped CrOOH nanomaterial, and preparation method and application thereof

Abstract

This invention discloses a Cu-doped CrOOH nanomaterial, its preparation method, and its applications, relating to the field of solar cell technology. The material is synthesized via a hydrothermal method, utilizing Cu… 2+ Doping modulates the band structure of CrOOH, enhancing its p-type conductivity and improving energy level matching with the perovskite light-absorbing layer. The surface of Cu-doped CrOOH nanomaterials is rich in hydroxyl functional groups, which can uniformly adsorb and self-assemble into monolayers, forming stable interfacial dipoles, enhancing the built-in electric field, promoting efficient extraction and transport of photogenerated holes, and suppressing interfacial recombination. Applying this material as a hole transport layer in an inverted perovskite solar cell, combined with SAM interface modification, significantly improves the device's photoelectric conversion efficiency and stability. The device constructed based on this structure achieves a photoelectric conversion efficiency of 25.0% and an open-circuit voltage of 1.22 V. This invention provides a novel hole transport material and its interface modulation strategy for efficient and stable inverted perovskite solar cells.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, specifically to a Cu-doped CrOOH nanomaterial, its preparation method, and its application. Background Technology

[0002] Perovskite solar cells have been extensively studied in recent years due to their advantages such as high absorption coefficient, long carrier diffusion length, and low-cost solution processing. Based on different device structures, they can be divided into two types: upright structure (nip) and inverted structure (pin). In inverted structure perovskite solar cells, the hole transport layer (HTL) is directly deposited on the surface of a transparent conductive substrate. It not only performs the functions of photogenerated hole extraction and transport but also affects the crystallinity quality of the perovskite thin film, interface energy level matching, and carrier recombination behavior, thus being a crucial functional layer determining device performance.

[0003] Currently, the most commonly used hole transport materials in inverted perovskite solar cells include PEDOT:PSS, PTAA, and NiO. x Among them, PEDOT:PSS has the problem of strong acidity and hygroscopicity, which can easily affect the long-term stability of the device; PTAA, although it can achieve high device efficiency, has a high material cost and poor wettability to perovskite precursor solutions, which is not conducive to large-scale industrial applications; NiO x While exhibiting good chemical stability and optical transmittance, these materials still suffer from low conductivity, numerous interface defects, and insufficient energy level matching, limiting further improvements in device performance. Furthermore, existing inorganic hole transport materials generally suffer from low hole mobility, suboptimal interface energy levels, and numerous interface defects, leading to easy recombination of photogenerated carriers at the HTL / perovskite interface, thus limiting further improvements in device open-circuit voltage, fill factor, and photoelectric conversion efficiency. Simultaneously, these materials typically lack high-density active groups on their surfaces, making it difficult to achieve high-density uniform adsorption of self-assembled monolayers (SAMs). Insufficient interfacial dipole modulation capability also hinders effective control of the spreading and crystallization behavior of perovskite precursor solutions, easily resulting in small perovskite film grain sizes and numerous grain boundary defects.

[0004] In recent years, inorganic metal oxide hole transport materials have attracted attention due to their low cost and good stability. CrOOH is a transition metal hydroxyl oxide material with good chemical stability and abundant surface hydroxyl groups. Surface hydroxyl groups are beneficial for the adsorption of self-assembled monolayers (SAMs), providing favorable conditions for surface modification and interface control. However, undoped CrOOH materials still suffer from problems such as valence band mismatch with the perovskite absorber layer, insufficient hole transport capacity, and low interface charge extraction efficiency, making it difficult to meet the requirements of high-efficiency perovskite solar cells for the hole transport layer. Studies have shown that by introducing appropriate metal doping, the band structure and carrier transport performance of semiconductor materials can be effectively controlled. Among them, Cu doping can change the electronic structure of the material, improve hole conductivity, and is expected to improve the energy level matching relationship between CrOOH and the perovskite absorber layer.

[0005] Therefore, developing a Cu-doped CrOOH nanomaterial and applying it to inverted perovskite solar cells has significant research value and application prospects. Summary of the Invention

[0006] This invention addresses the problems of low hole mobility, interfacial energy level mismatch, numerous interfacial defects, and insufficient device stability in existing inverted perovskite solar cells. It provides a hydrothermal synthesis method for Cu-doped CrOOH nanomaterials and, for the first time, applies it to the hole transport layer of perovskite solar cells. This invention modulates the band structure of CrOOH through Cu doping, reducing the HTL / PVK interfacial barrier. Simultaneously, it utilizes the abundant hydroxyl groups on the CrOOH surface to achieve uniform and dense adsorption of self-assembled monolayers (SAMs), enhancing the interfacial dipole and built-in electric field. This synergistically improves the extraction and transport efficiency of photogenerated holes, reduces interfacial carrier recombination, improves the crystallinity of the perovskite thin film, and ultimately achieves high photoelectric conversion efficiency and excellent device stability.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A Cu-doped CrOOH nanomaterial, wherein the Cu doping molar ratio is Cr:Cu = 10:(6~12), and when the Cu-doped CrOOH nanomaterial is used as a hole transport layer, the photoelectric conversion efficiency of the device after being combined with a self-assembled monolayer is ≥25.0%, and the open-circuit voltage is ≥1.22 V.

[0009] Furthermore, when the Cu-doped CrOOH nanomaterial is used as a hole transport layer, its device performance is superior to that of pure CrOOH, undoped CrOOH, or other Cr-based hole transport materials, and the photoelectric conversion efficiency is improved by at least 80%.

[0010] Furthermore, the XRD pattern of the Cu-doped CrOOH nanomaterial shows the crystalline structure of CrOOH and does not contain the characteristic diffraction peaks of copper-containing impurity phases.

[0011] Furthermore, the molar ratio of Cr to Cu in the Cu-doped CrOOH nanomaterial is 10:9.

[0012] A method for preparing Cu-doped CrOOH nanomaterials includes the following steps: dissolving a chromium source and a copper source in a surfactant solution at a molar ratio of Cr:Cu = 10:(6~12), adding ethylene glycol and an alkaline precipitant to form a hydroxide precursor precipitate containing chromium and copper; transferring the reaction solution containing the precursor precipitate to a reaction vessel and performing a hydrothermal reaction at 160~200℃ for 2~4 hours to convert the hydroxide precursor into Cu-doped CrOOH; after the reaction is completed, allowing it to cool naturally, washing the resulting precipitate sequentially with dilute ammonia, deionized water, ethanol, and isopropanol, and centrifuging to obtain the Cu-doped CrOOH nanomaterials.

[0013] Furthermore, the surfactant is P123, the chromium source is chromium nitrate or chromium sulfate; the copper source is copper nitrate; and the alkaline precipitant is NaOH or KOH.

[0014] An inverted perovskite solar cell includes a transparent conductive substrate, a hole transport layer, a self-assembled monolayer, a perovskite light-absorbing layer, an interface passivation layer, an electron transport layer, a hole blocking layer, and a metal electrode. The hole transport layer is characterized by being a Cu-doped CrOOH nanomaterial, and the self-assembled monolayer is adsorbed onto the surface of the hole transport layer.

[0015] Furthermore, the Cu doping molar ratio in the Cu-doped CrOOH nanomaterial is Cr:Cu = 10:(6~12); the self-assembled monolayer is one of MeO-2PACz, MeO-4PACz, or 2PACz.

[0016] Furthermore, the molar ratio of Cu doping in Cu-doped CrOOH nanomaterials is 10:9.

[0017] Furthermore, the self-assembled monolayer is MeO-2PACz.

[0018] Furthermore, the device has a photoelectric conversion efficiency of 25.0%, an open-circuit voltage of 1.22 V, and a fill factor of 0.85.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] Using the Cu-doped CrOOH nanomaterial of this invention as a hole transport layer can significantly improve the photoelectric conversion efficiency of inverted perovskite solar cells to 25.0% and the open-circuit voltage to 1.22 V. This is in contrast to existing Cr-based hole transport materials, such as pure CrOOH and CrO2. x Compared to other methods, the efficiency improvement exceeds 80%, demonstrating outstanding technological advantages.

[0021] This invention achieves simultaneous optimization of the electronic structure of the hole transport layer, the interface energy level, and the thin film crystallization behavior, providing a new technical solution for high-efficiency inverted perovskite solar cells. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the device of the present invention.

[0023] Figure 2 The XRD of Embodiment 1, Embodiment 6 of the present invention and the standard card are compared.

[0024] Figure 3 The current-voltage characteristic curves of the devices prepared in Examples 1, 6, 7, and 8 of this invention are shown.

[0025] Figure 4 This is a schematic diagram of the surface morphology of the device prepared in Example 1.

[0026] Figure 5 A cross-sectional photograph of the device prepared in Example 1.

[0027] Figure 6 TEM image of the nanoparticles prepared in Example 1.

[0028] Figure 7 The JV curve of the device prepared in Example 1 under AM 1.5G standard illumination.

[0029] Figure 8 Comparison of Cu 2p XPS of CrOOH nanomaterials before and after Cu doping. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides a Cu-doped CrOOH nanomaterial, its preparation method, and its applications. By controlling the band structure of the CrOOH nanomaterial through Cu doping and combining it with self-assembled monolayers (SAMs) interface modification technology, efficient energy level matching and interface electric field modulation between the hole transport layer and the perovskite light-absorbing layer are achieved, thereby improving the photoelectric conversion efficiency and stability of the device.

[0032] The perovskite solar cell constructed in this invention adopts an inverted structure, and its device structure is as follows: Figure 1 :

[0033] in:

[0034] FTO is a transparent conductive glass substrate used for collecting and transporting charge carriers;

[0035] CrOOH:Cu is a hole transport layer of Cu-doped CrOOH nanomaterials, used to extract and transport photogenerated holes;

[0036] SAM is a self-assembled monolayer used to control the interfacial energy level alignment and interfacial electric field.

[0037] Perovskite is a perovskite light-absorbing layer used to absorb sunlight and generate electron-hole pairs;

[0038] mF-peacl is an interface passivation layer used to reduce surface defect density;

[0039] PCBM stands for electronic transport layer;

[0040] BCP stands for hole blocking layer;

[0041] Ag is a metallic electrode.

[0042] Example 1

[0043] Preparation of CrOOH:Cu nanoparticles

[0044] A 20 mg / mL P123 solution (using deionized water) was prepared and magnetically stirred for at least 12 h. 0.5 mmol of chromium nitrate and 0.45 mmol of copper nitrate were weighed and added to a beaker (the molar ratio of Cr to Cu precursors was 10:9). 4 mL of the prepared P123 solution was added, and the mixture was stirred until completely dissolved. Then, 3.5 mL of ethylene glycol was slowly added, and the mixture was stirred continuously until homogeneous. 5 mL of a pH 14 NaOH solution was prepared and added dropwise to the mixture under high-speed stirring to form a pre-precipitate. The mixture was stirred for another 1 h. The resulting reaction solution was transferred to a polytetrafluoroethylene-lined reactor, filling it to 80% of its total volume. The reactor was placed in a 180℃ drying oven for a hydrothermal reaction for 3 h. After the reaction was complete and the mixture was allowed to cool naturally to room temperature, the precipitate was washed sequentially with dilute ammonia, deionized water, ethanol, and isopropanol. The supernatant was removed by centrifugation. Finally, the precipitate was added to 15 mL of a 1:1 mixture of dimethyl sulfoxide and isopropanol and ultrasonically dispersed for 3 h to obtain a CrOOH:Cu nanoparticle dispersion.

[0045] Perovskite solar cell fabrication

[0046] FTO conductive glass was cut into 1.5 cm × 1.5 cm pieces, and a 4 mm wide conductive isolation region was formed by laser etching. The substrate was ultrasonically cleaned sequentially in ethanol, deionized water, and ethanol for 30 min, followed by UV ozone treatment. The CrOOH:Cu nanoparticle dispersion prepared in Example 1 was spin-coated onto the FTO substrate surface at 4000 rpm for 30 s, followed by annealing at 100 °C for 2 min to form a hole transport layer. A MeO-2PACz isopropanol solution was prepared and spin-coated at 4000 rpm for 30 s, followed by annealing for 5 min to form a SAM interface modification layer. Subsequently, a perovskite precursor solution was prepared: 568 mg lead iodide, 66 mg cesium iodide, 80 mg lead bromide, 187 mg formamidinium iodide, and 12 mg methyl bromide were dissolved in a mixed solvent of 800 μL DMF and 200 μL DMSO. The perovskite precursor was deposited using a two-step spin-coating method: the first step was spin-coating at 500 rpm for 5 s; the second step was spin-coating at 5000 rpm for 45 s; and 100 μL of a chlorobenzene / acetonitrile (volume ratio 100:6) mixed antisolvent was added 30 s after the second spin-coating. After spin-coating, the perovskite light-absorbing layer was formed by annealing at 100℃ for 10 min. Subsequently, an mF-peacl interface modification layer and a PCBM electron transport layer were spin-coated sequentially. Finally, an 8 nm BCP layer and an 80 nm Ag electrode were deposited by thermal evaporation to obtain the complete device.

[0047] FTO / CrOOH:Cu / MeO-2PACz / Perovskite / mF-peacl / PCBM / BCP / Ag

[0048] Device performance testing

[0049] Simulated sunlight at AM 1.5G (100 mW / cm²) 2 Under these conditions, the current density-voltage (JV) characteristics of the device were tested using a CHI660 electrochemical workstation. During the test, a gradient scanning voltage (horizontal axis) was continuously applied to the device, and the current value corresponding to each voltage point was collected in real time. The current density (vertical axis) was then converted into the effective light-receiving area of ​​the device to obtain the JV curve.

[0050] Depend on Figure 7 From the JV curve, we can see that the intercept on the horizontal axis is the open-circuit voltage V. oc =1.22 V, the ordinate intercept is the short-circuit current density J sc = 24.1 mA / cm 2 The power (current density × voltage) at each point on the curve has a maximum value, called the maximum power point (MPP). The corresponding power value is the device's photoelectric conversion efficiency (PCE), which was measured to be 25.0%. The fill factor (FF) is calculated by dividing the power at the maximum power point by (V... oc ×J sc The calculated value is 0.85. These results demonstrate that the device of this invention exhibits excellent photovoltaic performance.

[0051] Example 2: The main feature of this example is that the chromium source used in the preparation of the hole transport material is chromium sulfate. The remaining steps are the same as in Example 1. See Table 1.

[0052] Example 3: The main feature of this example is the use of KOH as a precipitating agent. The remaining steps are the same as in Example 1. See Table 1.

[0053] Example 4: The main feature of this example is that the Cr:Cu feeding ratio is 10:6. The remaining steps are the same as in Example 1. See Table 2.

[0054] Example 5: The main feature of this example is that the Cr:Cu feeding ratio is 10:12. The remaining steps are the same as in Example 1. See Table 2.

[0055] Example 6: Without adding copper nitrate. Prepare pure CrOOH. The remaining steps are the same as in Example 1. See Table 3.

[0056] Example 7: CrOOH:Cu was used as HTL. The interface was not modified with MeO-2PACz. The remaining steps were the same as in Example 1. See Table 3.

[0057] Example 8: CrOOH as HTL. No copper doping was introduced; the interface was modified with MeO-4PACz. The remaining steps were the same as in Example 1. See Table 3.

[0058] Example 9: Hydrothermal temperature 160℃, Cr:Cu feed ratio 10:9, reaction time 3 h. The remaining steps are the same as in Example 1. See Table 4.

[0059] Example 10: Hydrothermal temperature 200℃, Cr:Cu feed ratio 10:9, reaction time 3 h. The remaining steps are the same as in Example 1. See Table 4.

[0060] Example 11: Hydrothermal time 2 h, Cr:Cu feed ratio 10:9, reaction temperature 180℃. The remaining steps are the same as in Example 1. See Table 5.

[0061] Example 12: Hydrothermal time 4 h, Cr:Cu feed ratio 10:9, reaction temperature 180℃. The remaining steps are the same as in Example 1. See Table 5.

[0062] Example 13: CrOOH:Cu was used as HTL. The interface was modified with MeO-4PACz. The remaining steps were the same as in Example 1. See Table 6.

[0063] Example 14: CrOOH:Cu was used as HTL. The interface was modified with 2PACz. The remaining steps were the same as in Example 1. See Table 6.

[0064] Table 1. Parameters of perovskite solar cells prepared with different chromium sources or precipitants

[0065] Chromium source and precipitant <![CDATA[Current density (mA / cm 2 )]]> Voltage (V) Fill factor efficiency(%) Example 1 <![CDATA[Cr(NO3)3 NaOH]]> 24.1 1.22 0.85 25.0 Example 2 <![CDATA[Cr2(SO4)3 NaOH]]> 24.0 1.21 0.84 24.4 Example 3 <![CDATA[Cr(NO3)3 KOH]]> 23.5 1.20 0.83 23.4

[0066] Table 2. Parameters of perovskite solar cells prepared with different Cr:Cu feed ratios

[0067] Feed molar ratio <![CDATA[Current density (mA / cm 2 )]]> Voltage (V) Fill factor efficiency(%) Example 4 10：6 21.0 1.15 0.79 19.0 Example 1 10：9 24.1 1.22 0.85 25.0 Example 5 10：12 23.2 1.20 0.82 23.2

[0068] Table 3 Photovoltaic performance parameters of perovskite solar cells fabricated with different hole transport layers

[0069] Hole transport layer <![CDATA[Current density (mA / cm 2 )]]> Voltage (V) Fill factor efficiency(%) Example 6 CrOOH 18.1 1.13 0.67 13.7 Example 7 CrOOH:Cu 23.8 1.19 0.80 22.7 Example 8 CrOOH(S) 23.6 1.18 0.83 23.1 Example 1 CrOOH:Cu(S) 24.1 1.22 0.85 25.0

[0070] Note: (S) represents SAM modification.

[0071] Table 4. Parameters of perovskite solar cells prepared at different hydrothermal temperatures

[0072] hydrothermal temperature <![CDATA[Current density (mA / cm 2 )]]> Voltage (V) Fill factor efficiency(%) Example 9 160℃ 23.4 1.18 0.82 22.6 Example 1 180℃ 24.1 1.22 0.85 25.0 Example 10 200℃ 23.5 1.21 0.84 23.9

[0073] Table 5. Parameters of perovskite solar cells prepared with different hydrothermal reaction times

[0074] hydrothermal time <![CDATA[Current density (mA / cm 2 )]]> Voltage (V) Fill factor efficiency(%) Example 11 2h 23.0 1.19 0.83 22.7 Example 1 3h 24.1 1.22 0.85 25.0 Example 12 4h 23.9 1.22 0.84 24.5

[0075] Table 6. Parameters of perovskite solar cells prepared with different self-assembled molecular interface modifications

[0076] Self-assembled molecules <![CDATA[Current density (mA / cm 2 )]]> Voltage (V) Fill factor efficiency(%) Example 1 MeO-2PACz 24.1 1.22 0.85 25.0 Example 13 MeO-4PACz 22.5 1.20 0.82 22.2 Example 14 2PACz 22.9 1.19 0.83 22.6

[0077] Figure 2 The XRD patterns showed that the characteristic diffraction peak positions of the Cu-doped CrOOH nanomaterial (Example 1) matched well with those of the undoped CrOOH (Example 6) and the standard card. No diffraction peaks of other new phases appeared, indicating that the main crystal structure of the material remains chromium hydroxyl oxide. 2+ It has replaced Cr in the crystal lattice 3+ The doping site was completed, but the crystal phase framework remained unchanged.

[0078] Due to Cu 2+ With Cr 3+ The ionic radii differ, and the diffraction peaks of the Cu-doped sample shift towards lower angles relative to pure CrOOH, indicating that doping causes lattice expansion.

[0079] like Figure 8 The fine XPS spectra of Cu shown demonstrate the presence of Cu in the Cu-doped CrOOH nanomaterials of this invention. The undoped pure CrOOH sample exhibits only instrument baseline noise and no Cu characteristic signal in the binding energy range corresponding to the Cu 2p orbital (930–960 eV); while the Cu-doped CrOOH sample prepared in Example 1 clearly shows Cu 2p orbital binding energy. 3 / 2 Cu2p 1 / 2 Characteristic main peak, and Cu was observed simultaneously. 2+ The corresponding characteristic satellite companion peaks. The above XPS test results directly confirm that Cu element exists in the Cu-doped CrOOH sample, and is present as divalent Cu ions (Cu... 2+ (in the form of ).

[0080] The core technology of this invention lies in constructing a Cu-doped CrOOH nanomaterial and using it as the hole transport layer material in an inverted perovskite solar cell. Specifically, Cu doping modulates the band structure and Fermi level position of the CrOOH material, achieving energy level matching with the perovskite light-absorbing layer. Simultaneously, the abundant hydroxyl groups on the CrOOH surface enable uniform and dense adsorption of self-assembled monolayers (SAMs), constructing an interfacial electric field conducive to hole extraction and transport, thereby synergistically improving the photoelectric conversion efficiency and stability of the device.

[0081] The core technical solution of this invention lies in the modulation of the electronic structure of CrOOH materials by Cu doping. 2+Upon entering the CrOOH lattice, its d orbitals hybridize with Cr-O orbitals, forming an acceptor-type intermediate energy level within the material's band gap. This lowers the Fermi level position and enhances the material's p-type conductivity. Simultaneously, Cu doping raises the valence band position of CrOOH, enabling better energy level matching with the valence band top of the perovskite absorber layer, reducing the hole transport barrier, and improving hole extraction efficiency.

[0082] The surface of CrOOH materials is rich in hydroxyl functional groups, providing abundant binding sites for the adsorption of SAM molecules. SAM modification can form a stable interfacial dipole between the hole transport layer and the perovskite layer, promoting interfacial band bending, enhancing the built-in electric field, thereby accelerating the transfer of photogenerated holes from the perovskite layer to the hole transport layer and suppressing electron recombination losses at the interface. Cu doping and SAM modification can also improve the wettability of the hole transport layer surface, enhance the spreading ability of the perovskite precursor solution on the substrate surface, promote uniform nucleation and grain growth of the perovskite film, and thus obtain perovskite films with higher crystal quality and lower defect density.

[0083] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification.

Claims

1. A Cu-doped CrOOH nanomaterial, characterized in that, In the Cu-doped CrOOH nanomaterial, the molar ratio of Cu doping is Cr:Cu = 10:(6~12). When the Cu-doped CrOOH nanomaterial is used as a hole transport layer, the photoelectric conversion efficiency of the device after being combined with the self-assembled monolayer is ≥25.0%, and the open-circuit voltage is ≥1.22 V.

2. The nanomaterial according to claim 1, characterized in that, When the Cu-doped CrOOH nanomaterial is used as a hole transport layer, its device performance is superior to that of pure CrOOH, undoped CrOOH, or other Cr-based hole transport materials, and the photoelectric conversion efficiency is improved by at least 80%.

3. The nanomaterial according to claim 1, characterized in that, The XRD pattern of the Cu-doped CrOOH nanomaterials shows the crystalline structure of CrOOH and does not contain the characteristic diffraction peaks of copper-containing impurities.

4. A method for preparing Cu-doped CrOOH nanomaterials according to any one of claims 1-3, characterized in that, The process includes the following steps: dissolving chromium and copper sources in a surfactant solution at a molar ratio of Cr:Cu = 10:(6~12), adding ethylene glycol and an alkaline precipitant to form a hydroxide precursor precipitate containing chromium and copper; transferring the reaction solution containing the precursor precipitate to a reaction vessel and performing a hydrothermal reaction at 160~200℃ for 2~4 hours to convert the hydroxide precursor into Cu-doped CrOOH; after the reaction is completed, allowing it to cool naturally, washing the resulting precipitate sequentially with dilute ammonia, deionized water, ethanol, and isopropanol, and centrifuging to obtain the Cu-doped CrOOH nanomaterial.

5. The preparation method according to claim 4, characterized in that, The surfactant is P123, the chromium source is chromium nitrate or chromium sulfate, the copper source is copper nitrate, and the alkaline precipitant is NaOH or KOH.

6. An inverted perovskite solar cell, comprising a transparent conductive substrate, a hole transport layer, a self-assembled monolayer, a perovskite light-absorbing layer, an interface passivation layer, an electron transport layer, a hole blocking layer, and a metal electrode, characterized in that, The hole transport layer is a Cu-doped CrOOH nanomaterial, and the self-assembled monolayer is adsorbed on the surface of the hole transport layer.

7. The inverted perovskite solar cell according to claim 6, characterized in that, The Cu doping molar ratio of Cu in the Cu-doped CrOOH nanomaterial is Cr:Cu = 10:(6~12); the self-assembled monolayer is one of MeO-2PACz, MeO-4PACz or 2PACz.

8. The inverted perovskite solar cell according to claim 6, characterized in that, The Cu doping molar ratio in Cu-doped CrOOH nanomaterials is 10:

9.

9. The inverted perovskite solar cell according to claim 6, characterized in that, The self-assembled monolayer is MeO-2PACz.

10. The inverted perovskite solar cell according to claim 6, characterized in that, The device has a photoelectric conversion efficiency of 25.0%, an open-circuit voltage of 1.22 V, and a fill factor of 0.85.

Images