Rubidium chloride doped perovskite, perovskite solar cell and preparation method thereof

Abstract

The present application discloses a rubidium chloride doped perovskite, a perovskite solar cell and a preparation method thereof, wherein the rubidium chloride doped perovskite comprises a perovskite main body and (PbI2)2RbCl, and an XRD characteristic peak of (PbI2)2RbCl is located at 11.3°. The perovskite solar cell comprises a substrate, an electron transport layer, a perovskite light absorption layer, a passivation layer, a hole transport layer and a metal electrode which are sequentially stacked.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the field of solar cells, and particularly relates to a rubidium chloride doped perovskite, a perovskite solar cell and a preparation method thereof. BACKGROUND

[0002] As a new type of solar cell, perovskite solar cells have become a hot spot in the field of thin film solar cells due to low cost and simple preparation process. At present, the performance of perovskite solar cells is improved mainly by high-quality perovskite film growth, cation and anion doping, carrier transport layer optimization and passivation engineering. Through these means, the highest efficiency of perovskite solar cells has exceeded 25%. In the current research, in order to prepare high-performance perovskite solar cells, there is usually some excess lead iodide in the perovskite light-absorbing layer. The excess lead iodide can play a role in passivating defects at the grain boundaries of perovskite, thereby positively affecting the performance of perovskite solar cell devices. However, the excess lead iodide will lead to an increase in hysteresis and a decrease in performance during long-term operation or storage, thereby affecting the stability of the device. SUMMARY

[0003] In view of the above technical problems, the present disclosure provides a rubidium chloride doped perovskite, a perovskite solar cell and a preparation method thereof, so as to at least partially solve the above technical problems.

[0004] In order to solve the above technical problems, as one aspect of the present disclosure, a rubidium chloride doped perovskite is provided, the rubidium chloride doped perovskite comprising a perovskite body and (PbI2)2RbCl, wherein the XRD characteristic peak of (PbI2)2RbCl is located at 11.3°.

[0005] In one embodiment, the perovskite body comprises formamidinium lead iodide.

[0006] As another aspect of the present disclosure, a perovskite solar cell is provided, the perovskite solar cell comprising: a perovskite light-absorbing layer, the perovskite light-absorbing layer comprising a rubidium chloride doped perovskite.

[0007] In another embodiment, the perovskite solar cell comprises a substrate, an electron transport layer, a perovskite light-absorbing layer, a passivation layer, a hole transport layer and a metal electrode which are sequentially stacked.

[0008] In another embodiment, the perovskite solar cell satisfies at least one of the following conditions:

[0009] The material of the substrate comprises transparent conductive glass;

[0010] The material of the electron transport layer comprises tin dioxide;

[0011] The material of the passivation layer includes phenethylammonium iodide;

[0012] The material of the hole transport layer includes 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene;

[0013] The metal electrode includes gold.

[0014] As an aspect of the present disclosure, a method for preparing a perovskite solar cell is provided, comprising:

[0015] preparing an electron transport layer on a substrate;

[0016] preparing a perovskite light-absorbing layer on the electron transport layer;

[0017] preparing a passivation layer on the perovskite light-absorbing layer;

[0018] preparing a hole transport layer on the passivation layer; and

[0019] preparing a metal electrode on the hole transport layer,

[0020] The perovskite light-absorbing layer is formed by a two-step spin-coating method:

[0021] In the first step, rubidium chloride is doped into a lead iodide solution and spin-coated onto the electron transport layer, and after a first annealing treatment, a lead iodide thin film is obtained;

[0022] In the second step, an organic salt solution is spin-coated onto the lead iodide thin film, and after a second annealing treatment, a rubidium chloride-doped perovskite light-absorbing layer is obtained.

[0023] In one of the embodiments,

[0024] The organic salt solution includes an organic solution of formamidinium iodide and methylamine chloride;

[0025] The temperature of the first annealing treatment includes 50-80°C;

[0026] The temperature of the second annealing treatment includes 100-150°C;

[0027] The molar ratio of rubidium chloride to lead iodide includes 0-10% mol:1;

[0028] The concentration of the lead iodide solution includes 1.1-1.7M.

[0029] In one of the embodiments, instead of the two-step spin-coating method, the perovskite light-absorbing layer is formed by a one-step spin-coating method:

[0030] The rubidium chloride is added into a mixed solution of lead iodide and an organic salt, the mixed solution is spin-coated onto an electron transport layer by a spin coating method, extraction is performed by using an organic solvent during the spin coating process, and annealing treatment is performed after the spin coating is completed, so as to obtain a rubidium chloride-doped perovskite light-absorbing layer.

[0031] In one of the embodiments, the temperature of the annealing treatment comprises 100-150 DEG C.

[0032] The present disclosure also provides an application of the rubidium chloride-doped perovskite or perovskite solar cell in the field of solar cells.

[0033] Based on the above technical solution, the present disclosure provides a rubidium chloride-doped perovskite, a perovskite solar cell and a preparation method thereof, and at least one of the following beneficial effects is achieved:

[0034] (1) In the embodiments of the present disclosure, the rubidium chloride is introduced into the perovskite material and reacts with the by-product lead iodide (PbI2) which is unstable in the perovskite itself to generate a new material (PbI2)2RbCl with better optical stability and XRD characteristic peaks at 11.3°. By controlling the content of PbI2 in the perovskite light-absorbing layer through this method, the generation of lead element (Pb°) is hindered, the activation energy of defect ion migration in the perovskite light-absorbing layer is increased from 0.32 eV to 1.03 eV, the movement of defect ions in the perovskite material is inhibited, and thus a perovskite light-absorbing layer with higher quality and better optical stability is obtained, which prevents the increase of hysteresis of the device during long-term operation or storage, and further enables the preparation of a perovskite solar cell with higher performance and higher stability.

[0035] (2) The perovskite light-absorbing layer prepared based on the rubidium chloride-doped perovskite is used to prepare a perovskite solar cell, and by optimizing the content of the rubidium chloride doping, a higher photoelectric conversion efficiency can be obtained in the laboratory, with a maximum of 26.1%, and an authentication efficiency of 25.56%±0.82% can be obtained.

[0036] (3) By using the method provided by the present disclosure, a perovskite solar cell with higher performance and better stability can be easily prepared. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is an X-ray diffraction pattern of the perovskite light-absorbing layer with or without rubidium chloride doping in the embodiments of the present disclosure;

[0038] Figure 2 is a structural schematic diagram of the perovskite solar cell in the embodiments of the present disclosure;

[0039] Figure 3 is a method flow schematic diagram for preparing the perovskite solar cell in the embodiments of the present disclosure;

[0040] Figure 4 This is a current-voltage characteristic curve of the perovskite solar cell in Embodiment 1 of this disclosure;

[0041] Figure 5 These are current-voltage characteristic curves showing the effect of different rubidium chloride doping amounts on the performance of perovskite solar cells in Examples 1-3 and Comparative Example 1 of this disclosure.

[0042] Figure 6 This is a current-voltage characteristic curve of the perovskite solar cell in Embodiment 1 of this disclosure before and after 1000 hours of placement;

[0043] Figure 7 This is a current-voltage characteristic curve showing the effect of rubidium chloride doping on the performance of perovskite solar cells in Example 4 and Comparative Example 1 of this disclosure. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0045] The perovskite light-absorbing layer is the core component of a perovskite solar cell, and its quality and stability determine the overall performance of the solar cell. In existing technologies, to obtain high-performance perovskite solar cells, an excess of lead iodide is present in the perovskite light-absorbing layer, either within the layer itself or on its surface. While this excess lead iodide can passivate defects at the perovskite grain boundaries and positively impact device performance, lead iodide is a photosensitive material with high activity. Excess lead iodide leads to a lower ion migration activation energy in the perovskite light-absorbing layer, further resulting in lower stability and higher hysteresis in the perovskite solar cell device. This disclosure addresses the issue of instability in the perovskite light-absorbing layer by doping it with rubidium chloride in the perovskite precursor solution. The rubidium chloride reacts with excess lead iodide (PbI₂) within the perovskite to form (PbI₂)₂RbCl, which inhibits the migration of defect ions within the perovskite, aiding in the preparation of a higher-quality, more stable perovskite light-absorbing layer and improving the overall performance and stability of the perovskite solar cell.

[0046] According to embodiments of the present disclosure, a rubidium chloride-doped perovskite comprises a perovskite body and (PbI2)2RbCl, wherein the XRD characteristic peak of (PbI2)2RbCl is located at 11.3°.

[0047] According to embodiments of this disclosure, the perovskite body comprises formamidinium lead iodine.

[0048] Figure 1This is an X-ray diffraction pattern of the perovskite light-absorbing layer with and without rubidium chloride doped in the embodiments of this disclosure.

[0049] like Figure 1 As shown, rubidium chloride was incorporated into perovskite, and a (PbI2)2RbCl material was generated by the reaction of rubidium chloride with an excess of unstable byproduct (PbI2) in the perovskite material. X-ray diffraction (XRD) characterization of the material revealed that the characteristic peak of (PbI2)2RbCl was located at 11.3°.

[0050] Through the embodiments of this disclosure, the introduced rubidium chloride can not only improve the crystal quality of perovskite, but also combine with the excess lead iodide in the perovskite to redshift the perovskite band gap, hinder the generation of elemental lead (Pb°) in the perovskite, and suppress the movement of defective ions in the perovskite, thus obtaining a perovskite light-absorbing layer with higher quality and higher stability.

[0051] According to an embodiment of this disclosure, a perovskite solar cell is provided, comprising: a perovskite light-absorbing layer, the perovskite light-absorbing layer comprising rubidium chloride-doped perovskite, wherein the perovskite light-absorbing layer can be prepared by a two-step spin-coating method or a one-step spin-coating method.

[0052] Figure 2 This is a schematic diagram of the structure of a perovskite solar cell in an embodiment of this disclosure.

[0053] According to embodiments of this disclosure, such as Figure 2 As shown, the perovskite solar cell includes a substrate 210, an electron transport layer 220, a perovskite light-absorbing layer 230, a passivation layer 240, a hole transport layer 250, and a metal electrode 260 stacked sequentially.

[0054] According to embodiments of this disclosure, the substrate acts as a support for transporting electrons from the electron transport layer to the outside of the solar cell.

[0055] According to embodiments of this disclosure, an electron transport layer is used to transport electrons generated by the perovskite light-absorbing layer to the substrate.

[0056] According to embodiments of this disclosure, a perovskite light-absorbing layer is used to absorb electron-hole pairs generated by sunlight, wherein the perovskite light-absorbing layer includes a perovskite host and (PbI2)2RbCl, and the perovskite host includes formamidinium lead iodine (FAPbI3).

[0057] According to embodiments of this disclosure, a passivation layer is used to passivate surface defects on a perovskite light-absorbing layer.

[0058] According to embodiments of this disclosure, a hole transport layer is used to transport holes generated by the perovskite light-absorbing layer to a metal electrode.

[0059] According to embodiments of this disclosure, a metal electrode is used to collect holes transported by the hole transport layer and recombine them with electrons from the substrate to form a circuit, thereby obtaining a perovskite solar cell.

[0060] According to embodiments of this disclosure, perovskite solar cells satisfy at least one of the following conditions:

[0061] The substrate material includes transparent conductive glass, which may be ITO or FTO conductive glass; the electron transport layer material includes tin dioxide; the passivation layer material includes phenylethyl ammonium iodide; the hole transport layer material includes 2,2′,7,7′-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9′-spirodifluorene; and the metal electrode material includes gold.

[0062] It should be noted that the materials of the substrate, electron transport layer, perovskite light-absorbing layer, passivation layer, hole transport layer and metal electrode listed in the embodiments of this disclosure are not limited to the listed materials, and other commonly used materials can be flexibly selected as needed.

[0063] According to embodiments of this disclosure, the thickness of the tin oxide electron transport layer can be 20-100 nm.

[0064] According to embodiments of this disclosure, the thickness of the perovskite light-absorbing layer can be 300-900 nm.

[0065] According to embodiments of this disclosure, the thickness of the passivation layer can be 10-30 nm.

[0066] According to embodiments of this disclosure, the thickness of the hole transport layer can be 150-250 nm.

[0067] According to embodiments of this disclosure, the thickness of the metal electrode can be 60-120 nm.

[0068] By limiting the thicknesses of the electron transport layer, perovskite light-absorbing layer, passivation layer, hole transport layer, and metal electrode within this range through the embodiments of this disclosure, higher light transmittance and absorption can be obtained, thereby improving the performance of perovskite solar cells.

[0069] According to embodiments of this disclosure, a method for fabricating a perovskite solar cell includes: fabricating an electron transport layer on a substrate; fabricating a perovskite light-absorbing layer on the electron transport layer; fabricating a passivation layer on the perovskite light-absorbing layer; fabricating a hole transport layer on the passivation layer; and fabricating a metal electrode on the hole transport layer; wherein the perovskite light-absorbing layer is formed by a two-step or one-step spin-coating method.

[0070] Figure 3 This is a schematic diagram of the method for preparing perovskite solar cells in the embodiments of this disclosure.

[0071] likeFigure 3 As shown, the method for preparing perovskite solar cells includes steps S301 to S306.

[0072] Step S301: Clean the substrate sequentially with detergent, deionized water, acetone, and isopropanol.

[0073] Step S302: Spin-coat tin oxide onto the substrate to prepare an electron transport layer.

[0074] Step S303: Prepare a perovskite light-absorbing layer on the electron transport layer using spin coating.

[0075] Step S304: Prepare a passivation layer on the perovskite light-absorbing layer using a solution spin-coating method.

[0076] Step S305: Prepare a hole transport layer on the passivation layer using a solution spin coating method.

[0077] Step S306: Prepare a metal electrode on the hole transport layer using vacuum evaporation.

[0078] The perovskite solar cells with high performance and good stability can be easily prepared using the methods in the embodiments of this disclosure.

[0079] According to an embodiment of this disclosure, in step S301, the substrate needs to be pretreated before the electron transport layer is prepared, including cleaning the ITO or FTO conductive glass substrate with detergent, deionized water, acetone and isopropanol (IPA) for 30 minutes each for later use. The resistance of the ITO layer is measured to be about 15 ohms.

[0080] According to an embodiment of this disclosure, in step S302, the preparation of an electron transport layer on the substrate includes: drying the cleaned ITO glass with an N2 gun and then performing UV-ozone treatment on its surface; then spin-coating the treated SnO2 nanoparticle solution onto the treated ITO glass to form a thin film; and then performing thermal annealing and ultraviolet ozone treatment to form a tin oxide electron transport layer, wherein the solvent in the SnO2 nanoparticle solution is water.

[0081] According to embodiments of this disclosure, the temperature of the heat annealing treatment includes 140-160°C, wherein 140, 150, or 160°C can be selected; the time of the heat annealing treatment includes 15-30 minutes, wherein 15, 20, 25, or 30 minutes can be selected.

[0082] According to embodiments of this disclosure, the ultraviolet ozone treatment time includes 10-30 minutes, wherein 10, 20, or 30 minutes may be selected.

[0083] According to an embodiment of this disclosure, in step S303, the preparation of a perovskite light-absorbing layer on the electron transport layer includes: incorporating rubidium chloride in different molar ratios into a perovskite precursor solution, spin-coating the perovskite precursor onto the electron transport layer using a spin-coating method, and then performing an annealing treatment to obtain the perovskite light-absorbing layer.

[0084] According to embodiments of this disclosure, obtaining a perovskite light-absorbing layer using spin coating includes: a two-step spin coating method and a one-step spin coating method.

[0085] According to embodiments of this disclosure, obtaining a perovskite light-absorbing layer via a two-step spin-coating method includes:

[0086] The first step involves incorporating rubidium chloride into a lead iodide solution and spin-coating it onto an electron transport layer. After a first annealing treatment, a lead iodide film is obtained. The second step involves spin-coating an organic salt solution onto the lead iodide film and performing a second annealing treatment to obtain a rubidium chloride-doped perovskite light-absorbing layer.

[0087] According to embodiments of this disclosure, the temperature of the first annealing treatment is 50-80°C, and the time of the first annealing treatment is 0.5-2 min; the temperature of the second annealing treatment is 100-150°C, and the time of the second annealing treatment is 10-30 min.

[0088] According to embodiments of this disclosure, the organic salt solution comprises an organic solution of formamidinium iodide (FAI) and methylamine chloride (MACl), wherein the solvent in the organic salt solution comprises isopropanol.

[0089] According to embodiments of this disclosure, the concentration of formamidinium iodide (FAI) is 60-110 mg / mL; the concentration of methylamine chloride (MACl) is 6-18 mg / mL.

[0090] According to embodiments of this disclosure, the molar ratio of rubidium chloride to lead iodide includes 0-10% mol: 1, wherein the ratio can be selected as 0: 1, 1: 1, 3: 1, 5: 1, 7: 1, 10% mol: 1, etc.

[0091] According to embodiments of this disclosure, the organic solvent in the lead iodide solution includes N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), wherein the concentration of the lead iodide solution includes 1.1-1.7M, and can be selected as 1.1, 1.3, 1.5, or 1.7M.

[0092] According to embodiments of this disclosure, instead of a two-step spin coating method, a perovskite light-absorbing layer is formed by a one-step spin coating method: rubidium chloride is incorporated into a mixed solution of lead iodide and organic salt, and the mixed solution is spin-coated onto the electron transport layer. During the spin coating process, extraction is performed using antisolvents such as chlorobenzene and diethyl ether. After spin coating, an annealing treatment is performed to obtain a rubidium chloride-doped perovskite light-absorbing layer. The annealing temperature in the one-step spin coating method includes 100-150°C.

[0093] According to the embodiments of this disclosure, the main body of the perovskite light-absorbing layer includes FAPbI3. By incorporating rubidium chloride (RbCl) in different molar ratios, the excess lead iodide content in the perovskite can be controlled. Since RbCl reacts with PbI2 to generate a new material (PbI2)2RbCl, the movement of defect particles in the perovskite is suppressed, thereby obtaining a perovskite light-absorbing layer with higher quality and higher stability.

[0094] According to an embodiment of the present disclosure, in step S304, the preparation of a passivation layer on the perovskite light-absorbing layer includes: spin-coating a phenylethyl ammonium iodide (PEAI) solution onto the surface of the perovskite light-absorbing layer to obtain a passivation layer, wherein the solvent in the phenylethyl ammonium iodide solution includes isopropanol.

[0095] According to an embodiment of this disclosure, in step S305, preparing a hole transport layer on the passivation layer includes: spin-coating a 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirodifluorene (Spiro-oMeTAD) solution onto the surface of the passivation layer to obtain a hole transport layer, wherein the solvent in the Spiro-oMeTAD solution includes chlorobenzene.

[0096] According to an embodiment of this disclosure, in step S306, the preparation of a metal electrode on the hole transport layer includes: depositing metal onto the surface of the hole transport layer using a vacuum evaporation method.

[0097] According to embodiments of this disclosure, the application of rubidium chloride-doped perovskite or perovskite solar cells in the field of batteries is also provided.

[0098] The technical solutions of this disclosure will be further explained and illustrated below with reference to specific embodiments and accompanying drawings. It should be noted that the specific embodiments described below are merely illustrative examples, and the scope of protection of this disclosure is not limited thereto.

[0099] Example

[0100] Example 1

[0101] The specific steps for fabricating perovskite solar cells using the two-step spin-coating method are as follows:

[0102] S1. Clean the substrate sequentially with detergent, deionized water, acetone and isopropanol (IPA);

[0103] S2. After drying the cleaned ITO glass with an N2 gun, perform UV-ozone treatment on its surface. Then, spin-coat the treated SnO2 nanoparticle solution onto the treated ITO glass to form a thin film. After thermal annealing and UV ozone treatment, an electron transport layer of tin oxide is formed.

[0104] S3. Add 5% rubidium chloride to a lead iodide solution and spin-coat it onto the electron transport layer. After a first annealing treatment, a lead iodide film is obtained. Then, spin-coat an organic salt solution onto the lead iodide film and anneal it a second time to obtain a rubidium chloride-doped perovskite light-absorbing layer.

[0105] S4. Spin-coat a phenylethyl ammonium iodide (PEAI) solution onto the surface of the perovskite light-absorbing layer to obtain a passivation layer.

[0106] S5. Spin-coat a solution of 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirodifluorene (Spiro-oMeTAD) onto the surface of the passivation layer to obtain a hole transport layer.

[0107] S6. Au is deposited on the surface of the hole transport layer by vacuum evaporation to obtain a metal electrode Au, thereby obtaining a perovskite solar cell.

[0108] Example 2

[0109] The preparation method in Example 2 is the same as that in Example 1, except that the molar ratio of rubidium chloride is 1%.

[0110] Example 3

[0111] The preparation method in Example 3 is the same as that in Example 1, except that the molar ratio of rubidium chloride is 10%.

[0112] Comparative Example 1

[0113] The preparation method in Comparative Example 1 is the same as that in Example 1, except that the perovskite light-absorbing layer contains only the perovskite host formamidinium lead iodine (FAPbI3).

[0114] Figure 4 This is a current-voltage characteristic curve of the perovskite solar cell in Embodiment 1 of this disclosure.

[0115] like Figure 4 As shown, current-voltage (IV) tests were performed on the perovskite solar cell prepared in Example 3, revealing a conversion efficiency of 26.1%, achieving a certified efficiency of 25.56% ± 0.82%. This demonstrates that a high-quality, stable perovskite light-absorbing layer can be easily prepared using a simple rubidium chloride doping method on the perovskite precursor solution. This improves the perovskite crystal quality, hinders the generation of elemental lead within the perovskite, and suppresses the migration of defect ions within the perovskite, thereby resulting in a high photoelectric conversion efficiency for the perovskite solar cell.

[0116] Figure 5The figures show the current-voltage characteristic curves of the effects of different rubidium chloride doping amounts on the performance of perovskite solar cells in Examples 1-3 and Comparative Example 1 of this disclosure. It can be seen from the figures that the device exhibits the best performance when the perovskite is doped with 5% mol RbCl. Too little doping will not allow more lead iodide to participate in the reaction, while too much doping will cause more (PbI2)2RbCl to adhere to the upper surface of the perovskite light-absorbing layer, affecting carrier transport, especially leading to a decrease in the device fill factor. Therefore, 5% mol doping was selected as the optimal doping amount.

[0117] like Figure 5 As shown in the figure, the comparison shows that the perovskite solar cell with a rubidium chloride molar ratio of 5% has a higher conversion efficiency, reaching 26.1%, which exceeds the 25% conversion efficiency of perovskite solar cells reported in the prior art.

[0118] Figure 6 This is a current-voltage characteristic curve of the perovskite solar cell in Embodiment 1 of this disclosure before and after 1000 hours of placement.

[0119] like Figure 6 As shown, after 1004 hours, the forward and reverse sweeps of the current-voltage characteristic curve of the perovskite solar cell did not change significantly, indicating that the perovskite light-absorbing layer has high quality and stability, thus enabling the perovskite solar cell to have high performance and stability.

[0120] Example 4

[0121] The preparation method of Example 4 is the same as that of Example 1, except that a one-step spin coating method is used to prepare the perovskite light-absorbing layer. Specifically, 5% rubidium chloride is incorporated into a mixed solution of lead iodide solution and organic salt solution. The mixed solution is then spin-coated onto the electron transport layer. After annealing, a rubidium chloride-doped perovskite light-absorbing layer is obtained.

[0122] Figure 7 This is a current-voltage characteristic curve showing the effect of rubidium chloride doping on the performance of perovskite solar cells in Example 4 and Comparative Example 1 of this disclosure.

[0123] like Figure 7 As shown, perovskite solar cells fabricated using the one-step method exhibit higher current density and photoelectric conversion efficiency than those fabricated using undoped rubidium chloride. Although the performance of devices fabricated using the one-step method is lower than that of the two-step method due to differences in laboratory processes, RbCl still demonstrates advantages over the two-step method.

[0124] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A rubidium chloride doped perovskite light absorbing layer, characterized in that, The rubidium chloride doped perovskite light absorbing layer comprises a perovskite host and (PbI2)2RbCl, wherein the XRD characteristic peak of (PbI2)2RbCl is located at 11.3°; The perovskite host comprises formamidinium lead iodide; The (PbI2)2RbCl is generated by the reaction of rubidium chloride and lead iodide, which is a by-product unstable in itself in the perovskite light absorbing layer.

2. A perovskite solar cell, characterized by, The perovskite solar cell comprises a perovskite light absorbing layer, which is the rubidium chloride doped perovskite light absorbing layer of claim 1.

3. The perovskite solar cell according to claim 2, characterized in that, The perovskite solar cell comprises a substrate, an electron transport layer, a perovskite light absorbing layer, a passivation layer, a hole transport layer and a metal electrode which are sequentially stacked.

4. The perovskite solar cell according to claim 3, characterized in that, The perovskite solar cell satisfies at least one of the following conditions: The material of the substrate comprises transparent conductive glass; The material of the electron transport layer comprises tin dioxide; The material of the passivation layer comprises phenethylammonium iodide; The material of the hole transport layer comprises 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene; The metal electrode comprises gold.

5. A method for preparing the perovskite solar cell of any one of claims 2 to 4, comprising: preparing an electron transport layer on a substrate; preparing a perovskite light absorbing layer on the electron transport layer; preparing a passivation layer on the perovskite light absorbing layer; preparing a hole transport layer on the passivation layer; and preparing a metal electrode on the hole transport layer, characterized in that the perovskite light absorbing layer is formed by a two-step spin-coating method: in a first step, rubidium chloride is doped into a lead iodide solution and spin-coated onto the electron transport layer, and after a first annealing treatment, a lead iodide film is obtained; in a second step, an organic salt solution is spin-coated onto the lead iodide film, and after a second annealing treatment, a rubidium chloride doped perovskite light absorbing layer is obtained.

6. The method of claim 5, characterized in that: the organic salt solution comprises an organic solution of formamidinium iodide and methylamine chloride; the temperature of the first annealing treatment comprises 50-80℃; the temperature of the second annealing treatment comprises 100-150℃; the molar ratio of rubidium chloride to lead iodide comprises 1%-10% mol:1; the concentration of the lead iodide solution comprises 1.1-1.7M. Instead of the two-step spin-coating method, the perovskite light absorbing layer is formed by a one-step spin-coating method:

7. The method of claim 5, wherein, rubidium chloride is doped into a mixed solution of lead iodide and organic salt, the mixed solution is spin-coated onto the electron transport layer by spin-coating method, extraction is performed with an organic solvent during the spin-coating process, and after the spin-coating technique, an annealing treatment is performed to obtain a rubidium chloride doped perovskite light absorbing layer. The temperature of the annealing treatment comprises 100-150℃.

8. The method of claim 7, wherein, 9. Use of the rubidium chloride doped perovskite light absorbing layer of claim 1 or the perovskite solar cell of any one of claims 2 to 4 in the field of cells. ​

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