Preparation method of tin-based perovskite thin film and application thereof in photoelectric devices

Abstract

The application discloses a preparation method of a tin-based perovskite film, and further discloses application of the tin-based perovskite film in photoelectric devices.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic materials and devices, and in particular to a method for preparing tin-based perovskite thin films and their application in optoelectronic devices. Background Technology

[0002] Ion migration is a significant cause of performance degradation and instability in halide perovskite optoelectronic devices. This phenomenon is widespread in organic-inorganic hybrid perovskites, all-inorganic perovskites, low-dimensional perovskites, and lead-free double perovskites. In monohalogen perovskites, ion migration leads to perovskite layer decomposition and hysteresis in the current-voltage curve. In mixed halide perovskites, ion migration causes severe phase separation, resulting in a redshift in the perovskite emission spectrum.

[0003] For photovoltaic devices, the maximum open-circuit voltage of the cell is limited to the I-rich region with a smaller bandgap, and the movement of halides also causes current hysteresis, resulting in limited device efficiency and stability. For perovskite light-emitting diodes (LEDs), phase separation fixes the emission wavelength in the near-infrared region emitted by the I-rich region, making wavelength tunability impossible. Therefore, it is necessary to address the instability problem of perovskite optoelectronic devices. Summary of the Invention

[0004] In view of this, the main objective of the present invention is to provide a method for preparing tin-based perovskite thin films and their application in optoelectronic devices, in order to at least partially solve one of the aforementioned technical problems.

[0005] As one aspect of the present invention, a method for preparing a tin-based perovskite thin film is provided, comprising:

[0006] A tin-based perovskite precursor solution was prepared using a mixed solution of tin halide and cesium halide, along with an organic amine salt.

[0007] The target tin-based perovskite thin film was obtained by spin-coating a pre-etched glass slide using a tin-based perovskite precursor solution.

[0008] According to an embodiment of the present invention, it further includes:

[0009] During spin coating, an anti-solvent is added dropwise within a preset time to obtain an initial tin-based perovskite film. The anti-solvent is a solvent that has the opposite dissolving effect to the solvent in the tin-based perovskite precursor solution.

[0010] The initial tin-based perovskite film was annealed to obtain the target tin-based perovskite film.

[0011] According to an embodiment of the present invention, after preparing a tin-based perovskite precursor solution using a mixed solution of tin halide, cesium halide, and an organic amine salt, the method further includes:

[0012] Add an oxidation inhibitor to the tin-based perovskite precursor solution.

[0013] According to an embodiment of the present invention, the oxidation inhibitor comprises tin fluoride;

[0014] The molar ratio of the oxidation inhibitor to the tin-based perovskite precursor solution is 1:9 to 3:7.

[0015] According to an embodiment of the present invention, the spin coating speed is 4000-6000 r / min.

[0016] According to an embodiment of the present invention, the mixed solution comprises: tin iodide, tin bromide, cesium iodide, and cesium bromide.

[0017] According to embodiments of the present invention, the organic amine salt includes PEAI. x Br 1-x Long-chain organic amine salts, 0 <x<1;

[0018] The molar ratio of organic amine salt to the mixed solution is 1:4 to 2:3.

[0019] As another aspect of the present invention, an application of tin-based perovskite thin films in optoelectronic devices is also provided.

[0020] According to an embodiment of the present invention, the optoelectronic device includes a tin-based perovskite light-emitting diode device.

[0021] According to an embodiment of the present invention, the method for fabricating a tin-based perovskite light-emitting diode device includes:

[0022] Provide a transparent conductive material;

[0023] A hole transport layer substrate is fabricated on a transparent conductive material;

[0024] Tin-based perovskite thin films were prepared on hole transport layer substrates using spin coating.

[0025] An electron transport layer, a blocking layer, and a metal electrode are sequentially fabricated on a perovskite thin film to obtain a tin-based perovskite light-emitting diode device. Attached Figure Description

[0026] Figure 1 A flowchart illustrating a method for preparing a tin-based perovskite thin film according to an embodiment of the present invention is shown schematically.

[0027] Figure 2(a) schematically shows the fluorescence spectra of the tin-based perovskite thin film before and after illumination according to an embodiment of the present invention;

[0028] Figure 2(b) schematically shows the fluorescence spectra of the lead-based perovskite thin film before and after illumination according to the comparative example of the present invention;

[0029] Figure 3(a) schematically shows the absorption spectra of the tin-based perovskite thin film before and after illumination according to an embodiment of the present invention;

[0030] Figure 3(b) schematically shows the absorption spectra of the lead-based perovskite thin film before and after illumination according to the comparative example of the present invention;

[0031] Figure 4(a) schematically shows the XRD patterns of the tin-based perovskite thin film before and after illumination according to an embodiment of the present invention;

[0032] Figure 4(b) schematically shows the XRD patterns of the lead-based perovskite thin film before and after illumination according to the comparative example of the present invention;

[0033] Figure 5 A schematic diagram of the structure of a lateral device according to an embodiment of the present invention is shown;

[0034] Figure 6(a) schematically illustrates the fluorescence changes of a lateral device obtained using a tin-based perovskite thin film according to an embodiment of the present invention before and after electric field polarization.

[0035] Figure 6(b) schematically illustrates the fluorescence changes of a lateral device obtained using a lead-based perovskite thin film according to the present invention before and after electric field polarization.

[0036] Figure 7(a) schematically shows the XPS energy spectrum of a tin-based perovskite thin film according to an embodiment of the present invention;

[0037] Figure 7(b) schematically shows the XPS energy spectrum of a lead-based perovskite thin film according to a comparative example of the present invention;

[0038] Figure 8(a) schematically illustrates the structure of a tin-based perovskite light-emitting diode device according to an embodiment of the present invention;

[0039] Figure 8(b) schematically illustrates a lead-based perovskite light-emitting diode device structure according to a comparative example of the present invention;

[0040] Figure 9 The electroluminescence spectrum of a tin-based perovskite light-emitting diode device under constant voltage is schematically shown according to an embodiment of the present invention.

[0041] Figure 10 The schematic diagram illustrates the electroluminescence spectrum of a lead-based perovskite light-emitting diode device according to the present invention under constant voltage.

[0042] [Attached image labels]

[0043] 1-Glass substrate; 2-Perovskite thin film; 3-Electrode. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention more clear and understandable, the following further elaborates on the present invention in detail with reference to specific embodiments and the accompanying drawings.

[0045] The following schematically illustrates a preparation method of a tin-based perovskite thin film and its application in optoelectronic devices. It should be noted that this illustrative example is only a specific embodiment of the present invention and does not limit the protection scope of the present invention.

[0046] Inhibiting and preventing ion movement in halide perovskites is a problem that must be solved in perovskite optoelectronic devices. Currently, most methods for inhibiting ion movement are through defect passivation. This method cannot completely inhibit ion movement in perovskites. Under the induction of external light illumination and electric fields, phase separation still occurs in mixed-halide perovskites.

[0047] Based on this, the present invention provides a preparation method of a tin-based perovskite thin film. By using metallic tin, which can form a stronger interaction with halogens, to replace commonly used metallic lead, the movement of halide ions is blocked, and the phase separation problem of mixed-halide perovskite LEDs is solved.

[0048] Figure 1 A flowchart of the preparation method of the tin-based perovskite thin film according to an embodiment of the present invention is schematically shown.

[0049] As Figure 1 shown, the preparation method of the tin-based perovskite thin film provided in this embodiment includes operations S101 to S102.

[0050] In operation S101, a tin-based perovskite precursor solution is prepared by using a mixed solution of tin halide and cesium halide and an organic amine salt.

[0051] According to an embodiment of the present invention, the mixed solution may include: tin iodide (SnI2), tin bromide (SnBr2), cesium iodide (CsI), and cesium bromide (CsBr). The solvent of the mixed solution may include dimethyl sulfoxide.

[0052] According to an embodiment of the present invention, the organic amine salt may include PEAI x Br 1-x long-chain organic amine salt, 0 < x < 1. The molar ratio of the organic amine salt to the mixed solution is 1:4 to 2:3. As a preference, the molar ratio of the organic amine salt to the mixed solution is 1:4.

[0053] It should be noted that the organic amine salt can improve the morphology of the target tin-based perovskite thin film. If the molar ratio of the organic amine salt to the mixed solution is lower than 1:4, the effect of improving the morphology of the target tin-based perovskite thin film may not be achieved. If the molar ratio of the organic amine salt to the mixed solution is higher than 2:3, the phase of the target tin-based perovskite thin film may change, transforming from three-dimensional to two-dimensional, affecting the conductivity.

[0054] For example, tin iodide (SnI₂), tin bromide (SnBr₂), cesium iodide (CsI), and cesium bromide (CsBr) can be dissolved in dimethyl sulfoxide in different stoichiometric ratios. Then, PEAI with an organic amine salt in a molar ratio of 1:4 to the mixed solution is added. x Br 1-x Long-chain organic amine salts were stirred to obtain tin-based perovskite precursor solution CsSn(I x Br 1-x 3, where 0 ≤ x ≤ 1. More specifically, x can be, but is not limited to, 0, 0.2, 0.4, 0.6, 0.8, and 1.

[0055] According to an embodiment of the present invention, after preparing a tin-based perovskite precursor solution using a mixed solution of tin halide, cesium halide, and an organic amine salt, the method may further include adding an oxidation inhibitor to the tin-based perovskite precursor solution.

[0056] According to embodiments of the present invention, the oxidation inhibitor may include tin fluoride (SnF2).

[0057] According to embodiments of the present invention, the molar ratio of the oxidation inhibitor to the tin-based perovskite precursor solution is 1:9 to 3:7. Preferably, the molar ratio of the oxidation inhibitor to the tin-based perovskite precursor solution is 1:4.

[0058] It should be noted that adding an oxidation inhibitor can inhibit Sn. 2+ Oxidation. If the molar ratio of the oxidation inhibitor to the tin-based perovskite precursor is less than 1:9, it may not be sufficient to inhibit Sn. 2+ The effect of oxidation. If the molar ratio of oxidation inhibitor to tin-based perovskite precursor solution is higher than 3:7, non-perovskite impurities will be introduced, affecting the performance of the prepared tin-based perovskite thin film.

[0059] According to an embodiment of the present invention, the preparation of tin-based perovskite precursor solution can be carried out in a nitrogen glove box.

[0060] In operation S102, a tin-based perovskite precursor solution is used to spin-coat a pre-etched glass slide to obtain the target tin-based perovskite film.

[0061] According to an embodiment of the present invention, the pre-etching treatment can be a pre-etching process using plasma etching. Etching can be performed for 10 minutes to improve the wettability of the glass slide.

[0062] According to embodiments of the present invention, the spin coating speed can be 4000–6000 r / min. Preferably, the spin coating speed can be 5000 r / min. If the spin coating speed is lower than 4000 r / min, the target tin-based perovskite film obtained by spin coating may be too thick. If the spin coating speed is higher than 6000 r / min, the target tin-based perovskite film obtained by spin coating may be too thin, and the tin-based perovskite precursor solution may easily be spun off.

[0063] According to an embodiment of the present invention, the method for preparing a tin-based perovskite thin film may further include: adding an anti-solvent dropwise within a preset time during spin coating to obtain an initial tin-based perovskite thin film, wherein the anti-solvent is a solvent that has the opposite dissolving effect to the solvent in the tin-based perovskite precursor solution; and annealing the initial tin-based perovskite thin film to obtain a target tin-based perovskite thin film.

[0064] According to an embodiment of the present invention, the preset time can be 1 to 2 seconds before the film changes color. The annealing treatment can be performed by annealing on a hot plate at 80°C for 10 minutes. The annealing treatment can remove residual solvent on the initial tin-based perovskite film.

[0065] According to an embodiment of the present invention, the above-described operation S102 can be performed in a nitrogen glove box. Testing in air can be performed by spin-coating a 200 mg / mL polymethyl methacrylate (PMMA) solution for encapsulation, wherein the PMMA is soluble in chlorobenzene (CB).

[0066] The preparation method of tin-based perovskite thin films is illustrated below with more specific embodiments. It should be noted that these examples are merely specific embodiments of the present invention and do not limit the scope of protection of the present invention.

[0067] Example 1: Preparation of tin-based perovskite thin films CsSn(I x Br 1-x )3(x=0, 0.2, 0.4, 0.6, 0.8, 1)

[0068] In a nitrogen-filled glove box, SnI₂, SnBr₂, CsI, and CsBr were dissolved in dimethyl sulfoxide in different stoichiometric ratios. Then, PEAI (a type of organic amine salt) was added at a molar ratio of 1:4 to the mixed solution. x Br 1-x Long-chain organic amine salts were reacted to obtain a 0.2 M solution, which was stirred overnight for later use. Then, SnF2 with an oxidation inhibitor in a molar ratio of 1:4 to this solution was added to obtain the tin-based perovskite precursor solution CsSn(I x Br 1-x )3(x=0, 0.2, 0.4, 0.6, 0.8, 1).

[0069] Comparative Example 1: Preparation of lead-based perovskite thin films CsPb(I x Br1-x )3(x=0, 0.2, 0.4, 0.6, 0.8, 1)

[0070] In a nitrogen-filled glove box, PbI₂, PbBr₂, CsI, and CsBr were dissolved in dimethyl sulfoxide in different stoichiometric ratios. Then, PEAI (a type of organic amine salt) was added at a molar ratio of 1:4 to the mixed solution. x Br 1-x Long-chain organic amine salts were used to obtain a 0.2 M solution, which was stirred overnight for later use to obtain lead-based perovskite thin films CsPb(I) x Br 1-x )3(x=0, 0.2, 0.4, 0.6, 0.8, 1).

[0071] Figure 2(a) schematically shows the fluorescence spectrum of a tin-based perovskite film before and after illumination according to an embodiment of the present invention; Figure 2(b) schematically shows the fluorescence spectrum of a lead-based perovskite film before and after illumination according to a comparative example of the present invention; Figure 3(a) schematically shows the absorption spectrum of a tin-based perovskite film before and after illumination according to an embodiment of the present invention; Figure 3(b) schematically shows the absorption spectrum of a lead-based perovskite film before and after illumination according to a comparative example of the present invention; Figure 4(a) schematically shows the XRD pattern of a tin-based perovskite film before and after illumination according to an embodiment of the present invention; Figure 4(b) schematically shows the XRD pattern of a lead-based perovskite film before and after illumination according to a comparative example of the present invention.

[0072] The CsSn(I) prepared in Example 1 and Comparative Example 1 were respectively used. x Br 1-x )3 and CsPb(I x Br 1-x 3. Irradiate the sample for 5 hours in a nitrogen glove box at one solar intensity (AM 1.5G), and compare the fluorescence spectrum, absorption spectrum and X-ray diffraction spectrum before and after irradiation, as shown in Figures 2 to 4.

[0073] As shown in Figure 2(a), CsSn(I x Br 1-x The fluorescence spectrum of CsPb(I) remained almost unchanged before and after illumination; however, in Figure 2(b), the fluorescence spectrum of CsPb(I) was significantly different. x Br 1-x The fluorescence spectrum of CsSn(I) changed significantly before and after illumination. As shown in Figure 3(a), the fluorescence spectrum of CsSn(I) changed significantly before and after illumination. x Br 1-x The absorption spectrum of CsPb(I) did not change before and after illumination; however, in Figure 3(b), the absorption spectrum of CsPb(I) remained unchanged. x Br 1-x )3 The absorption spectrum of CsSn(I) changed to some extent before and after illumination. As shown in Figure 4(a),x Br 1-x The XRD pattern of CsPb(I) remained almost unchanged before and after illumination; however, in Figure 4(b), the XRD pattern of CsPb(I) showed significant changes. x Br 1-x )3. The XRD patterns before and after illumination changed to some extent. All the above experiments demonstrate that metallic tin reacts more strongly with halogens than commonly used metallic lead. After illumination, CsSn(I x Br 1-x )3 can inhibit the migration of halogens and improve the stability of perovskite films.

[0074] Figure 5 A schematic diagram of the structure of a lateral device according to an embodiment of the present invention is shown.

[0075] like Figure 5 As shown, the lateral device in this embodiment includes a glass substrate 1, a perovskite thin film 2, and an electrode 3.

[0076] In this process, a perovskite thin film 2 is formed on a glass substrate 1; electrodes 3 are deposited at both ends of the perovskite thin film 2 to obtain a lateral device.

[0077] Example 2: Fabrication of lateral devices using tin-based perovskite thin films

[0078] CsSn(I) is formed on glass substrate 1 x Br 1-x )3 thin film, in CsSn(I x Br 1-x )3. An Au electrode with a thickness of 50 nm was deposited on the thin film, and the distance between the two Au electrodes was 100 μm.

[0079] Comparative Example 2: Fabrication of Lateral Devices Using Lead-Based Perovskite Thin Films

[0080] Similar to the above method for preparing lateral devices using tin-based perovskite thin films, CsSn(I x Br 1-x )3 The thin film was replaced with CsPb(I x Br 1-x )3 film.

[0081] It should be noted that the formation of CsSn(I) x Br 1-x The method for preparing thin films can be obtained from the tin-based perovskite thin films provided above.

[0082] Figure 6(a) schematically illustrates the fluorescence change of a lateral device obtained using a tin-based perovskite thin film according to an embodiment of the present invention before and after electric field polarization; Figure 6(b) schematically illustrates the fluorescence change of a lateral device obtained using a lead-based perovskite thin film according to a comparative example of the present invention before and after electric field polarization.

[0083] A voltage of 210V was applied across the electrodes using a Keithley 240 source meter, and the changes in perovskite fluorescence before and after the voltage application were compared, as shown in Figures 6(a) and 6(b).

[0084] As shown in Figure 6(a), using CsSn(I x Br 1-x The transverse device obtained in Figure 6(b) exhibits an emission wavelength of 750 nm before and after electric field polarization, remaining unchanged; while in Figure 6(b), the emission wavelength of the device obtained using CsPb(I) remains unchanged. x Br 1-x The emission wavelength of the lateral device obtained in step 3 changed significantly from 590 nm to 660 nm before and after electric field polarization. Experiments showed that metallic tin reacts more strongly with halogens than commonly used metallic lead; after applying voltage, CsSn(I x Br 1-x )3 can suppress halogen migration, prevent phase separation, and improve the stability of lateral devices.

[0085] Figure 7(a) schematically shows the XPS energy spectrum of a tin-based perovskite thin film according to an embodiment of the present invention; Figure 7(b) schematically shows the XPS energy spectrum of a lead-based perovskite thin film according to a comparative example of the present invention.

[0086] As shown in Figures 7(a) and 7(b), the binding energies of I and Br in tin-based perovskite films are greater than those in lead-based perovskite films. Experiments have demonstrated that the Sn-X bond energy is greater than the Pb-X bond energy. Due to the stronger bond energies in tin-based perovskite films, the migration of halogens can be suppressed and prevented.

[0087] Based on the above-described method for preparing tin-based perovskite thin films, this invention also provides an application of tin-based perovskite thin films in optoelectronic devices.

[0088] According to an embodiment of the present invention, the optoelectronic device includes: a tin-based perovskite light-emitting diode device.

[0089] According to embodiments of the present invention, a method for fabricating a tin-based perovskite light-emitting diode device may include:

[0090] Provide a transparent conductive material;

[0091] A hole transport layer substrate is fabricated on a transparent conductive material;

[0092] Tin-based perovskite thin films were prepared on hole transport layer substrates using spin coating.

[0093] An electron transport layer, a blocking layer, and a metal electrode are sequentially fabricated on a perovskite thin film to obtain a tin-based perovskite light-emitting diode device.

[0094] It should be noted that the tin-based perovskite thin film is prepared according to the tin-based perovskite thin film preparation method provided above.

[0095] According to embodiments of the present invention, the transparent conductive material may include ITO. The transparent conductive material ITO can be ultrasonically cleaned with detergent, deionized water, acetone and anhydrous ethanol respectively, and then the cleaned ITO is dried in an oven at 70°C for later use.

[0096] According to an embodiment of the present invention, a hole transport layer substrate can be prepared on a transparent conductive material by spin-coating a hole transport layer solution onto the transparent conductive material. The hole transport layer solution can be prepared by dissolving a polymeric hole transport material in a benzene-based solvent. During spin-coating, an appropriate amount of hole transport layer solution is used each time, with a spin speed of 1000–3000 r / min for approximately 60 seconds.

[0097] It should be noted that using an appropriate amount of hole transport layer solution can avoid both insufficient coverage of the transparent conductive material and excessive waste.

[0098] According to embodiments of the present invention, an electron transport layer, a barrier layer, and a metal electrode can be prepared by vapor deposition. The electron transport layer can be TPBi. The barrier layer can be LiF. The metal electrode can be Al. The thickness of the electron transport layer can be 20–60 nm. Preferably, the thickness of the electron transport layer is 40 nm. The thickness of the barrier layer can be 1–1.5 nm. Preferably, the thickness of the barrier layer is 1.2 nm. The thickness of the metal electrode can be 60–200 nm. Preferably, the thickness of the metal electrode is 100 nm.

[0099] It should be noted that the thickness of both the electron transport layer and the barrier layer affects the device's performance. If the metal electrode is too thin, the test probe will not function properly; if the metal electrode is too thick, it will result in a waste of resources.

[0100] The application of tin-based perovskite thin films in optoelectronic devices is illustrated below through more specific embodiments. It should be noted that these examples are merely specific embodiments of the present invention and do not limit the scope of protection of the present invention.

[0101] Figure 8(a) schematically illustrates the structure of a tin-based perovskite light-emitting diode device according to an embodiment of the present invention; Figure 8(b) schematically illustrates the structure of a lead-based perovskite light-emitting diode device according to a comparative example of the present invention.

[0102] Example 3: Fabrication of Tin-based Perovskite Light Emitting Diode Device

[0103] Transparent conductive material ITO was ultrasonically cleaned with detergent, deionized water, acetone, and anhydrous ethanol, respectively, and then dried in an oven at 70°C. Polymer hole transport material poly-TPD was dissolved in CB solution to prepare a hole transport layer solution. The preferred concentration of the hole transport layer solution was 6 mg / ml. Using a spin coater, 30 μL of the hole transport layer solution was applied to the dried ITO each time, at a speed of 2000 r / min for 60 s. The poly-TPD was annealed at 150°C for 20 min, and after complete cooling, a tin-based perovskite film CsSn(I) was spin-coated. x Br 1-x 3. The spin coating speed was 5000 r / min. During the spin coating process, an anti-solvent was added dropwise. Toluene was added dropwise 1-2 seconds before the film changed color to obtain a high-quality perovskite film. The perovskite film was then annealed on an 80℃ hot stage for 10 min to remove residual solvent. The electron transport layer, the blocking layer, and the metal electrode were prepared by vapor deposition. The electron transport layer was TPBi, the blocking layer was LiF, and the metal electrode was Al; their thicknesses were 40 nm, 1.2 nm, and 100 nm, respectively. The schematic diagram of the final tin-based perovskite light-emitting diode device is shown in Figure 8(a).

[0104] It should be noted that the poly-TPD layer has poor wettability and requires plasma treatment for 30 seconds before spin coating.

[0105] Comparative Example 3: Fabrication of lead-based perovskite light-emitting diode devices

[0106] The method for preparing tin-based perovskite light-emitting diode devices is similar to that in Example 3 above. The difference is that the polymer hole transport material poly-TPD is replaced with polymer hole transport material PVK. PVK is annealed at 120°C for 20 min, and after complete cooling, a lead-based perovskite thin film CsPb(I) is spin-coated. x Br 1-x 3. No plasma treatment for 30 seconds is required when spin-coating the lead-based perovskite thin film. The schematic diagram of the final fabricated lead-based perovskite light-emitting diode device is shown in Figure 8(b).

[0107] It should be noted that different perovskites require different hole transport layers. For example, tin-based perovskites require poly-TPD, while lead-based perovskites require PVK.

[0108] Figure 9 The electroluminescence spectrum of a tin-based perovskite light-emitting diode device under constant voltage is schematically shown according to an embodiment of the present invention. Figure 10 The schematic diagram illustrates the electroluminescence spectrum of a lead-based perovskite light-emitting diode device according to the present invention under constant voltage.

[0109] Figure 9 and Figure 10 The changes in the electroluminescence peaks of tin-based and lead-based perovskite light-emitting diodes over time are shown under a constant voltage of 4V. Figure 9 As shown in (a) to 9(d), CsSn(I x Br 1-x )3. The position of the electroluminescence peak of the light-emitting diode device did not shift within 300 seconds. However, as... Figure 10 As shown in (a) to 10(d), CsPb(I x Br 1-x )3. The electroluminescence peak of the light-emitting diode device exhibits a severe redshift within 100 s. Experimental results show that CsSn(I) without ion migration... x Br 1-x 3. Light-emitting diode (LED) devices exhibit better electro-spectral stability, enabling spectral tunability under LED operating conditions. However, the presence of CsPb(I) ions facilitates their movement. x Br 1-x 3. The spectrum of a light-emitting diode device red-shifts under operating voltage.

[0110] According to embodiments of the present invention, the present invention provides an application of tin-based perovskite thin films in optoelectronic devices. By suppressing halogen migration and preventing phase separation through the stronger Sn-X bond energy in Sn-based perovskite, the stability of perovskite optoelectronic devices is improved.

[0111] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a tin-based perovskite thin film, characterized in that, include: Add PEAI x Br 1-x Add a long-chain organic amine salt to a mixed solution of tin halide and cesium halide, and stir to obtain a tin-based perovskite precursor solution, where 0 < x < 1, and the PEAI x Br 1-x The molar ratio of the organic amine salt to the mixed solution is 1:4 to 2:3; Using the tin-based perovskite precursor solution, spin-coating is performed on a pre-etched glass slide to obtain a target tin-based perovskite thin film, which is used to prepare a tin-based perovskite light-emitting diode device. During spin coating, an anti-solvent is added 1-2 seconds before the film changes color to obtain an initial tin-based perovskite film. The anti-solvent is a solvent that has the opposite dissolving effect to the solvent in the tin-based perovskite precursor solution. The initial tin-based perovskite film is annealed to obtain the target tin-based perovskite film.

2. The preparation method according to claim 1, after preparing the tin-based perovskite precursor solution using a mixed solution of tin halide, cesium halide, and an organic amine salt, further includes: An oxidation inhibitor was added to the tin-based perovskite precursor solution.

3. The preparation method according to claim 2, wherein, The oxidation inhibitor includes tin fluoride; The molar ratio of the oxidation inhibitor to the tin-based perovskite precursor solution is 1:9 to 3:

7.

4. The preparation method according to claim 1, wherein, The spin coating speed is 4000~6000 r / min.

5. The preparation method according to claim 1, wherein, The mixed solution includes: tin iodide, tin bromide, cesium iodide, and cesium bromide.

6. The application of the tin-based perovskite thin film prepared by the preparation method according to any one of claims 1 to 5 in tin-based perovskite light-emitting diode devices.

7. The application according to claim 6, wherein, The fabrication method of the tin-based perovskite light-emitting diode device includes: Provide a transparent conductive material; A hole transport layer substrate is prepared on the transparent conductive material; Tin-based perovskite thin films were prepared on the hole transport layer substrate using a spin coating method. An electron transport layer, a blocking layer, and a metal electrode are sequentially fabricated on the perovskite thin film to obtain a tin-based perovskite light-emitting diode device.

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