Halogen-mixed perovskite solar cell and preparation method thereof
By optimizing the inorganic salt ratio and vapor deposition process of hybrid halide perovskite solar cells, the phase separation problem caused by halide ion migration was solved, improving device performance and stability, making them suitable for commercial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JITRI INST OF ORGANIC OPTOELECTRONICS CO LTD
- Filing Date
- 2026-01-28
- Publication Date
- 2026-04-28
AI Technical Summary
Hybrid halide perovskite solar cells are prone to phase separation due to halide ion migration under external stimuli, leading to degraded device performance and rapid degradation, which hinders commercialization.
By optimizing the halogen content in the inorganic salt, inorganic and organic films were prepared using a co-evaporation process. The evaporation rate was controlled to form a perovskite light-absorbing layer with an atomic ratio of I to Br of 2.3-2.5. Annealing was then carried out in a humidity glove box at 170 degrees Celsius and 36% RH to improve carrier transport capacity and uniform distribution of halogen ions.
It significantly improves the open-circuit voltage and photoelectric conversion efficiency of the device, enhances crystallinity and thin film density, achieves long-term working stability and excellent process compatibility, and is suitable for commercial production.
Smart Images
Figure CN121941191A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of solar cell technology, and in particular to a mixed halogen perovskite solar cell and its preparation method. Background Technology
[0002] Perovskite solar cells (PSCs), as a representative of the next generation of thin-film photovoltaic technology, have attracted much attention due to their advantages such as high photoelectric conversion efficiency, low cost, and simple fabrication process. Among them, organic-inorganic hybrid perovskite materials, especially formamidinium (… Perovskite, due to its ideal optical bandgap and excellent thermal stability, is considered an ideal light-absorbing layer material for realizing high-efficiency devices.
[0003] To further tune the bandgap for better photoelectric performance, bromine is typically introduced into perovskites. Partially replaces iodine ( ),form Mixed halide perovskites.
[0004] However, in practical applications, these mixed halide perovskites often undergo phase segregation, also known as halogen segregation. Under external stimuli such as light, electric fields, or heating, the halide ions in the crystal lattice ( Phase separation occurs, causing the originally uniform perovskite film to decompose into iodine-rich (I-rich) and bromine-rich (Br-rich) domains at the microscale. This phase separation significantly impairs device performance: the iodine-rich phase has a narrow band gap and becomes a non-radiative recombination center, leading to a significant decrease in the device's open-circuit voltage (Voc); simultaneously, the non-uniform phase distribution hinders carrier extraction and transport, causing a decrease in fill factor (FF) and ultimately, power conversion efficiency (PCE). More seriously, phase separation is a dynamic and irreversible degradation process, directly leading to rapid performance degradation in the device's operating state, severely restricting the commercialization of perovskite solar cells. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the purpose of this application is to provide a mixed-halogen perovskite solar cell and its preparation method, which effectively suppresses the phase separation problem of halogens and improves the overall performance of the mixed-halogen perovskite solar cell.
[0006] To achieve the above objectives, a mixed-halogen perovskite solar cell includes a transparent conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and a metal electrode stacked sequentially. The perovskite light-absorbing layer comprises an inorganic film layer and an organic film layer stacked sequentially from bottom to top. The thickness of the inorganic film layer is 300-400 nm, and the thickness of the organic film layer is 300-400 nm. The organic film layer is prepared by FAI evaporation, and the inorganic film layer is prepared by... , The perovskite light-absorbing layer is prepared by co-evaporation of CsI and Br, and the atomic ratio of I to Br in the perovskite light-absorbing layer is 2.3-2.5.
[0007] Furthermore, the aforementioned The evaporation rate is 1~10 A / s. The evaporation rate is 1~10 A / S, and the evaporation rate of CsI is 0.1~1 A / S.
[0008] Furthermore, the aforementioned The evaporation rate ratio of CsI and CsI satisfies: : CsI = 6:3.0:0.32.
[0009] Furthermore, the atomic ratio of I to Br in the perovskite light-absorbing layer is 2.41.
[0010] To achieve the above objectives, this application also provides a method for preparing a mixed-halogen perovskite solar cell, comprising: Clean the substrate, which consists of a substrate and a transparent conductive cathode, and dry it; A hole transport layer is prepared on the upper surface of the substrate; Use on the upper surface of the substrate An inorganic film layer of 300-400 nm was prepared by co-evaporation of CsI and then an organic film layer of 300-400 nm was prepared by FAI evaporation, forming a perovskite light-absorbing layer with an atomic ratio of I to Br of 2.3-2.5. An electron transport layer is prepared on the upper surface of the substrate; A metal anode is prepared on the upper surface of the substrate.
[0011] Furthermore, the evaporation rate of the PbI2 is 1~10 A / s. The evaporation rate is 1~10 A / S, and the evaporation rate of CsI is 0.1~1 A / S.
[0012] Furthermore, the aforementioned The evaporation rate ratio of CsI and CsI satisfies: : CsI = 6:3.0:0.32.
[0013] Furthermore, the atomic ratio of I to Br in the perovskite light-absorbing layer is 2.41.
[0014] Furthermore, it also includes: After preparing the perovskite active layer, it was annealed for 10 minutes in a humidity glove box at 170 degrees Celsius and 36% RH.
[0015] To achieve the above objectives, this application also provides a mixed halogen perovskite solar cell, which is prepared using the mixed halogen perovskite solar cell preparation method described above.
[0016] This application discloses a mixed-halogen perovskite solar cell, which improves the energy conversion efficiency and open-circuit voltage of the device by optimizing the proportion of halogen components in the inorganic salt.
[0017] This application discloses a mixed-halogen perovskite solar cell. By optimizing the iodine to bromine ratio in the entire perovskite light-absorbing layer, it promotes the preferential growth of crystals along the vertical direction, thereby enhancing the carrier transport capability and improving the device performance. On the other hand, it facilitates the uniform distribution of iodine and bromine ions in three-dimensional space, avoids compositional stratification in the vertical direction, significantly reduces the bulk defect density of the thin film, and thus greatly improves the open-circuit voltage and photoelectric conversion efficiency of the device.
[0018] This application presents a mixed-halogen perovskite solar cell that is perfectly suited to a high-precision vacuum evaporation process, exhibiting excellent process compatibility and scalability. The composition is controlled by adjusting the evaporation rate of each source material, resulting in a precise and repeatable method that is conducive to commercial production.
[0019] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing this application. Attached Figure Description
[0020] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the mixed halogen perovskite solar cell of Embodiment 1 of this application; Figure 2 A cross-sectional image of perovskite scanned by SEM. Figure 3 Image of the perovskite surface as scanned by SEM. Figure 4 XRD pattern of a perovskite solar cell with mixed halogens; Figure 5 A schematic diagram illustrating the stability testing of a perovskite solar cell with mixed halogens; Figure 6 This is a schematic diagram of the fabrication process of the mixed halogen perovskite solar cell of Example 2 of this application; In the figure: 10-transparent conductive substrate, 20-hole transport layer, 30-inorganic film layer, 40-organic film layer, 50-electron transport layer, 60-metal anode. Detailed Implementation
[0021] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.
[0022] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.
[0023] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.
[0024] It should be noted that the terms "one" and "multiple" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be interpreted as "one or more". "Multiple" should be understood as two or more.
[0025] The embodiments of this application will now be described in detail with reference to the accompanying drawings.
[0026] Example 1 One embodiment of this application provides a mixed halogen perovskite solar cell, such as... Figure 1 As shown, it includes: The transparent conductive substrate 10, hole transport layer 20, perovskite active layer, electron transport layer 50 and metal anode 60 are arranged sequentially from bottom to top. The perovskite light absorption layer includes an inorganic film layer 30 and an organic film layer 40 stacked sequentially from bottom to top.
[0027] In this embodiment, the hole transport layer 20 is formed by spin-coating SAM and has a thickness of 2 nm.
[0028] In other embodiments, the hole transport layer 20 may also be one or more of PTAA, PEDOT:PSS, F4-TCNQ, 2-PACZ or metal oxides.
[0029] In this embodiment, the organic film layer 40 is formed by FAI vapor deposition.
[0030] In this embodiment of the application, the inorganic film layer 30 is composed of It is prepared by co-evaporation of CsI.
[0031] In the embodiments of this application, the thickness of the organic film layer 40 is 300-400 nm, and the thickness of the inorganic film layer 30 is 300-400 nm.
[0032] It should be noted that the thickness of the organic film layer 40 is maintained at approximately a 1:1 ratio with the thickness of the inorganic film layer 30, so that the FAI in the organic film layer and the FAI in the inorganic film layer are balanced. FAPbI3 is formed by balancing CsI and CsI in a 1:1 ratio.
[0033] In this embodiment of the application, the inorganic film layer 30 The deposition rates of CsI and CsI were 6 A / s, 3 A / s and 0.32 A / s, respectively.
[0034] In some other implementations, And CsI can also be in The evaporation rate is 1~10 A / s. The evaporation rate is 1~10 A / s, and the evaporation rate of CsI is 0.1~1 A / s. Evaporation rate: Evaporation rate: CsI evaporation rate = 6:3.0:0.32 configuration, so that the atomic ratio of I to Br in the entire perovskite light-absorbing layer of the mixed halogen perovskite solar cell is 2.3-2.5.
[0035] Table 1 shows the elemental composition of the inorganic salt film layer in a basic perovskite solar cell. As shown in Table 1, the atomic ratio of Br is 36.02% and the atomic ratio of I is 33.54%. According to the organic-inorganic ratio of 1:1, the calculated Br is 36.02*2=72.04 and the I is 33.54*2+33.54+36.02=136.64. Therefore, I / Br=136.64 / 72.04=1.89.
[0036] Table 1:
[0037] Table 2 shows the elemental proportions in the inorganic salt film layer of a mixed halogen perovskite solar cell. As shown in Table 2, the atomic ratio of Br is 30.41% and the atomic ratio of I is 38.75%. According to the organic-inorganic 1:1 balance, the calculated Br ratio is I / Br = 2.41.
[0038] Table 2:
[0039] In this embodiment, the electron transport layer 50 is formed by evaporation of C60 and BCP, and its thickness ranges from 1 to 100 nm.
[0040] In other embodiments, the electron transport layer 50 may also be C60, BCP, PCBM, Bphen, Alq3, ZnO, etc. One or more of the following.
[0041] In the embodiments of this application, the metal anode 60 is formed by vapor deposition of Au, Ag, Al or Cu, and the thickness ranges from 50 to 300 nm.
[0042] Figure 2 Here is a cross-sectional image of the perovskite obtained by SEM scanning. Figure 3 Here is a SEM (Scanned Electron Microscopy) image of the perovskite surface, as shown below. Figure 2 and Figure 3 As shown, the grain size of perovskite is significantly increased and more uniformly distributed, crystallinity is improved, grain growth is more complete, grain boundaries are reduced, film density is significantly improved, and there are no obvious pores or cracks.
[0043] Figure 4 The XRD pattern of a perovskite solar cell with mixed halogens is shown below. Figure 4 As shown, the diffraction peak intensity of the mixed halogen perovskite thin film of this application is significantly enhanced on the (001) and (002) crystal planes, and the full width at half maximum (FWHM) is correspondingly narrowed, indicating that its crystallinity is significantly improved, the grain size is increased, and the crystal orientation is enhanced.
[0044] Figure 5 This is a schematic diagram illustrating the stability testing of a perovskite solar cell with mixed halogens, as shown below. Figure 5 As shown, the device retains 87.44% of its initial efficiency after more than 700 hours of continuous operation, demonstrating excellent long-term operational stability. The normalized photoelectric conversion efficiency decreases gradually over time without a sharp decline. The device exhibits good structural stability and fatigue resistance under nitrogen protection conditions, and the perovskite layer and interface degrade slowly under continuous illumination and bias voltage.
[0045] Example 2 One embodiment of this application provides a method for fabricating a mixed halogen perovskite solar cell, see reference. Figure 6 The preparation methods include: Step S101: Clean the substrate consisting of the substrate and the transparent conductive cathode, and dry it with nitrogen gas.
[0046] Step S102: Prepare a hole transport layer on the upper surface of the substrate; In this embodiment, the hole transport layer can be formed by coating SAM using any one of the following wet coating methods: spin coating, blade coating, slot coating, and spray coating.
[0047] In this embodiment, the hole transport layer may also be one or more of PTAA, PEDOT:PSS, F4-TCNQ, 2-PACZ or metal oxides, with a solution concentration of 1 to 20 mg / ml and a thickness range of 1 to 100 nm.
[0048] In this embodiment, the thermal annealing temperature range of the hole transport layer is 40 ~ 150°C.
[0049] Step S103: Use on the upper surface of the substrate An inorganic film layer of 300-400 nm was prepared by co-evaporation deposition of CsI and then an organic film layer of 300-400 nm was prepared by FAI deposition, forming a perovskite light-absorbing layer with an atomic ratio of I to Br of 2.3-2.5. In this embodiment, The evaporation rates of CsI were 6 A / s, 3 A / s, and 0.32 A / s, respectively, with a co-evaporation time of 332 s and a thickness of 310 nm.
[0050] In this embodiment, the organic film layer is prepared by FAI vapor deposition and has a thickness of 350 nm.
[0051] In this embodiment, after the organic film layer is deposited by vapor deposition, it is annealed for 10 minutes in a humidity glove box at 170 degrees Celsius and 36% RH.
[0052] In some other implementations, And CsI can also be in The evaporation rate is 1~10 A / s. The evaporation rate is 1~10 A / s, and the evaporation rate of CsI is 0.1~1 A / s. Evaporation rate: Evaporation rate: CsI evaporation rate = 6:3.0:0.32 configuration, so that the atomic ratio of I to Br in the entire perovskite light-absorbing layer of the mixed halogen perovskite solar cell is 2.3-2.5.
[0053] In other embodiments, the thickness of both the organic and inorganic film layers is configured to be 300-400 nm.
[0054] Step S104: Evaporate, spin-coate, scrape-coate, or spray an electron transport layer onto the perovskite active layer; In this embodiment, the electron transport layer is C60 and BCP, with a thickness ranging from 1 to 100 nm.
[0055] In other embodiments, the electron transport layer may also be C60, BCP, PCBM, Bphen, Alq3, ZnO, etc. One or more of the following.
[0056] In this embodiment, the thermal annealing temperature range for the electron transport layer is 40 ~ 150°C.
[0057] Step S105: Deposit a metal anode on the electron transport layer.
[0058] In this embodiment, the metal anode is Au, Ag, Al or Cu, and the thickness ranges from 50 to 300 nm.
[0059] Example 3 One embodiment of this application provides a mixed halogen perovskite solar cell, which is prepared using the mixed halogen perovskite solar cell preparation method described above.
[0060] The above description is merely a partial embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.
[0061] Furthermore, while the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in sequential order. Multitasking and parallel processing may be advantageous in certain environments. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this application. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.
[0062] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.
Claims
1. A perovskite solar cell with mixed halogens, characterized in that, The invention comprises a transparent conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and a metal electrode stacked sequentially. The perovskite light-absorbing layer consists of an inorganic film layer and an organic film layer stacked sequentially from bottom to top. The thickness of the inorganic film layer is 300-400 nm, and the thickness of the organic film layer is 300-400 nm. The organic film layer is prepared by FAI evaporation, and the inorganic film layer is prepared by a co-evaporation process using PbI2, PbBr2, and CsI. The atomic ratio of I to Br in the perovskite light-absorbing layer is 2.3-2.
5.
2. The perovskite solar cell with mixed halogens according to claim 1, characterized in that, The evaporation rate of PbI2 is 1~10 A / s, the evaporation rate of PbBr2 is 1~10 A / s, and the evaporation rate of CsI is 0.1~1 A / s.
3. The perovskite solar cell with mixed halogens according to claim 2, characterized in that, The evaporation rate ratio of PbI2, PbBr2 and CsI satisfies: PbI2 : PbBr2 : CsI = 6 : 3.0 : 0.
32.
4. The perovskite solar cell with mixed halogens according to claim 3, characterized in that, The atomic ratio of I to Br in the perovskite light-absorbing layer is 2.
41.
5. A method for preparing a perovskite solar cell with mixed halogens, characterized in that, include: Clean the substrate, which consists of a substrate and a transparent conductive cathode, and dry it; A hole transport layer is prepared on the upper surface of the substrate; An inorganic film layer of 300-400 nm was prepared on the upper surface of the substrate using a co-evaporation process with PbI2, PbBr2 and CsI. Then, an organic film layer of 300-400 nm was prepared by FAI evaporation to form a perovskite light-absorbing layer with an atomic ratio of I to Br of 2.3-2.
5. An electron transport layer is prepared on the upper surface of the substrate; A metal anode is prepared on the upper surface of the substrate.
6. The method for preparing a mixed halogen perovskite solar cell according to claim 5, characterized in that, The evaporation rate of PbI2 is 1~10 A / s, the evaporation rate of PbBr2 is 1~10 A / s, and the evaporation rate of CsI is 0.1~1 A / s.
7. The method for preparing a mixed halogen perovskite solar cell according to claim 6, characterized in that, The evaporation rate ratio of PbI2, PbBr2 and CsI satisfies: PbI2: PbBr2: CsI = 6:3.0:0.
32.
8. The method for preparing a mixed halogen perovskite solar cell according to claim 7, characterized in that, The atomic ratio of I to Br in the perovskite light-absorbing layer is 2.
41.
9. The method for preparing a mixed halogen perovskite solar cell according to claim 5, characterized in that, Also includes: After preparing the perovskite active layer, it was annealed for 10 minutes in a humidity glove box at 170 degrees Celsius and 36% RH.
10. A perovskite solar cell with mixed halogens, characterized in that, It is prepared using the method for preparing mixed halogen perovskite solar cells according to any one of claims 5-9.