Efficient all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification and preparation method of efficient all-inorganic tin-based perovskite light-emitting diode

Abstract

The embodiment of the invention discloses a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification and a preparation method of the high-efficiency all-inorganic tin-based perovskite light-emitting diode. The diode provided by the embodiment of the invention sequentially comprises an anode, a modified hole transport layer, a TPPO buried interface modification layer, a perovskite light-emitting layer, a post-processing layer, an electron transport layer, an electron injection layer and a cathode, wherein the TPPO buried interface modification layer is prepared by spin-coating a solution formed by dissolving a triphenylphosphine oxide solution (TPPO) in a dimethyl sulfoxide (DMSO) solvent on the modified hole transport layer; and the post-processing layer is prepared by spin-coating the perovskite light-emitting layer with a solution formed by dissolving 2, 7-bis (diphenyl phosphine oxide)-9, 9 '-spirobifluorene in chlorobenzene. According to the embodiment of the invention, regulation and control of interface chemical passivation and perovskite crystallization processes can be realized cooperatively, and the external quantum efficiency, the working stability and the film quality of the diode are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optoelectronic manufacturing, in particular to a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification and a preparation method thereof. BACKGROUND

[0002] Solution-processed metal halide perovskites have attracted great interest in photovoltaic and optoelectronic devices due to their excellent optoelectronic properties, such as high photoluminescence quantum yield (PLQY), tunable bandgap, and long carrier lifetime. In recent years, perovskite light-emitting diodes (PeLEDs) have made rapid progress, with external quantum efficiencies (EQEs) of green, red, and near-infrared devices exceeding 20%, showing great application potential. However, these high-performance results are mainly based on lead-containing perovskites, and their toxicity issues have hindered commercialization. Therefore, it is urgent to develop environmentally friendly and efficient lead-free alternatives.

[0003] Among the numerous lead-free alternatives, divalent tin (Sn 2+ ) is considered an ideal choice due to its similar ionic radius and electronic structure to lead (Pb 2+ ). Tin-based perovskites not only have low toxicity and environmental friendliness (degradation product is SnO2), but also have a narrower bandgap and higher carrier mobility. Currently, the efficiency of organic-inorganic hybrid tin-based PeLEDs has exceeded 20%, demonstrating the potential of tin-based systems.

[0004] However, the development of all-inorganic tin-based PeLEDs with better intrinsic thermal stability has lagged behind, with the highest reported efficiency of only about 7.6%, far lower than hybrid systems. The main reason for the efficiency difference is the two core challenges of all-inorganic systems: one is the easy oxidation of Sn 2 , leading to high defect density and severe non-radiative recombination, and the other is poor film quality, with rapid crystallization process resulting in rough, porous, and defect-rich thin films. Crucially, the two problems are coupled at the interface - interface defects not only accelerate Sn 2+ oxidation, but also induce heterogeneous nucleation, worsening the film morphology. Therefore, a synergistic interface engineering strategy that can simultaneously achieve interface chemical passivation and crystallization process regulation is urgently needed to break through the performance bottleneck of all-inorganic tin-based PeLEDs. SUMMARY

[0005] The embodiments of the present application provide a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification and a preparation method thereof, which can synergistically achieve interface chemical passivation and perovskite crystallization process regulation, improving the external quantum efficiency, working stability, and film quality of the diode.

[0006] This application provides a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification. The diode sequentially includes an anode, a modified hole transport layer, a TPPO buried interface modification layer, a perovskite light-emitting layer, a post-processing layer, an electron transport layer, an electron injection layer, and a cathode.

[0007] The modified hole transport layer is formed by spin-coating a mixture of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and sodium polystyrene sulfonate aqueous solution at a volume ratio of 1.2:1 onto the anode and then heat-annealing.

[0008] The TPPO buried interface modification layer is prepared by spin-coating a solution of triphenylphosphine oxide (TPPO) dissolved in dimethyl sulfoxide (DMSO) onto a modified hole transport layer.

[0009] The all-inorganic tin-based perovskite luminescent layer was prepared by spin-coating a perovskite precursor solution onto a TPPO buried substrate interface modification layer and then thermally annealing. The perovskite precursor solution was prepared by dissolving CsI, SnI2, and SnCl2 in DMSO solvent. CsI and total Sn... 2 + The molar ratio is 1:1, SnCl2 accounts for 10 mol% of the total tin source, and tin powder accounting for 10% of the total tin source mass is added;

[0010] The post-treatment layer was prepared by spin-coating a solution of 2,7-bis(diphenylphosphine)-9,9'-spirodifluorene dissolved in chlorobenzene onto the perovskite luminescent layer.

[0011] This application also provides a method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification, including:

[0012] CsI, SnI2, and SnCl2 were dissolved in dimethyl sulfoxide (DMSO) solvent, wherein CsI reacted with the total Sn. 2+ The molar ratio of SnCl2 to 10 mol% of the total tin source was 1:1, and tin powder accounting for 10% of the total tin source mass was added to prepare a perovskite precursor solution.

[0013] A modified hole transport layer solution was prepared by mixing poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) with an aqueous solution of sodium polystyrene sulfonate at a volume ratio of 1.2:1.

[0014] 2,7-bis(diphenylphosphine)-9,9'-spirodifluorene was dissolved in chlorobenzene to form a post-treatment solvent;

[0015] Triphenylphosphine oxide (TPPO) was dissolved in DMSO solvent to form a buried interface modification layer solution;

[0016] A modified hole transport layer, a TPPO buried interface modification layer, a perovskite luminescent layer, and a post-treatment layer are sequentially formed on the anode, wherein:

[0017] The modified hole transport layer is formed by spin-coating a modified hole transport layer solution onto the anode and then annealing.

[0018] The TPPO buried interface modification layer is formed by spin-coating a buried interface modification layer solution onto a modified hole transport layer;

[0019] The perovskite luminescent layer is formed by spin-coating a perovskite precursor solution onto a TPPO buried substrate interface modification layer and then thermally annealing.

[0020] The post-treatment layer is formed by spin-coating a post-treatment solvent onto the perovskite luminescent layer;

[0021] An electron transport layer, an electron injection layer, and a cathode are sequentially deposited on the post-processing layer to obtain an all-inorganic tin-based perovskite light-emitting diode.

[0022] In some embodiments, Sn in the perovskite precursor solution 2+ The concentration of tin powder is 0.25 mol / L, the amount of tin powder added is 10% of the total tin source mass, and the perovskite precursor solution is stirred at 25°C for no less than 9 hours.

[0023] In some embodiments, the concentration of sodium polystyrene sulfonate in the modified hole transport layer solution is 50 mg / mL.

[0024] In some embodiments, the concentration of the post-treatment solvent is 4 mg / mL.

[0025] In some embodiments, the concentration of TPPO in the subsurface interface modification layer solution is 4 mg / mL.

[0026] In some embodiments, the modified hole transport layer solution is spin-coated onto the anode at 4000 rpm for 40 seconds and then annealed at 150°C for 15 minutes.

[0027] In some embodiments, the modified hole transport layer is annealed at 110°C for 5 minutes, and then a substrate interface modification layer solution is spin-coated onto it at 2000 rpm for 60 seconds.

[0028] In some embodiments, the perovskite precursor solution is spin-coated onto the TPPO buried interface modification layer at a speed of 4000 rpm for 60 seconds. During the spin-coating process, 500 μL of chlorobenzene is added dropwise as an anti-solvent at the 38th second. The solution is then immediately transferred to a hot plate at the end of the spin-coating process and annealed at 110°C for 10 minutes.

[0029] In some embodiments, the post-treatment solvent is spin-coated onto the perovskite luminescent layer at a speed of 8000 rpm for 30 seconds.

[0030] The beneficial effects of the technical solutions provided in this application include at least the following:

[0031] This application introduces triphenylphosphine oxide (TPPO) as a TPPO buried interface modification layer between the hole transport layer and the all-inorganic tin-based perovskite luminescent layer, and further applies a 2,7-bis(diphenylphosphine oxide)-9,9'-spirodifluorene (SPPO13) post-treatment layer on the surface of the other side of the perovskite luminescent layer, thus constructing a "bottom-top synergistic" dual-interface passivation system.

[0032] Among them, the TPPO buried interface modification layer can be formed in one step by conventional spin coating, without the need for high temperature or complex processes. Its Lewis basic phosphino group can effectively passivate the defect states on the hole transport layer surface and suppress Sn at the interface. 2+ To Sn 4+ In addition to oxidation, it can also regulate the nucleation kinetics of perovskite precursors and slow down the crystallization rate, thereby promoting the formation of dense and uniform CsSnI3 films and avoiding pinhole and island growth caused by heterogeneous nucleation. At the same time, the TPPO buried interface modification layer can also block the penetration of oxygen and moisture into the perovskite light-emitting layer, improving the environmental stability of the diode.

[0033] On the other hand, the SPPO13 post-treatment layer, with its strong Lewis basicity, can efficiently passivate uncoordinated Sn at the top surface and grain boundaries of the perovskite luminescent layer. 2+ With iodine vacancies, it significantly inhibits non-radiative recombination on the surface and further isolates the perovskite luminescent layer from external environmental erosion.

[0034] The aforementioned dual-interface strategy simultaneously addresses the core coupling challenge in all-inorganic tin-based PeLEDs from both sides of the perovskite emitting layer—namely, how interface defects accelerate Sn... 2+ Oxidation induces heterogeneous nucleation and deteriorates the film morphology. By synergistically achieving chemical passivation and crystallization control, this application significantly reduces the bulk and interface defect density, optimizes film quality and carrier injection / recombination balance, and ultimately improves the external quantum efficiency (EQE) of the device to 5.81%. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of a high-efficiency all-inorganic tin-based perovskite light-emitting diode with TPPO interface modification provided in an embodiment of this application;

[0037] Figure 2a This is a schematic flowchart of a method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification, provided in an embodiment of this application.

[0038] Figure 2b This application provides the chemical structural formula and ball-and-stick model of TPPO.

[0039] Figure 2c This is a schematic diagram of the high-efficiency all-inorganic tin-based perovskite light-emitting diode in the original example;

[0040] Figure 2d This is a schematic diagram of the photoelectric performance of a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification according to an embodiment of this application;

[0041] Figure 2e This is a schematic diagram of the photoelectric performance of the high-efficiency all-inorganic tin-based perovskite light-emitting diode in the original example. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0043] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” “top,” and “bottom,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0044] Figure 1 This application provides an embodiment of a high-efficiency all-inorganic tin-based perovskite light-emitting diode with TPPO interface modification. For example... Figure 1As shown, the diode sequentially includes an anode 10, a modified hole transport layer 20, a TPPO buried interface modification layer 30, a perovskite light-emitting layer 40, a post-treatment layer 50, an electron transport layer 60, an electron injection layer 70, and a cathode 80.

[0045] The modified hole transport layer 20 is formed by spin-coating a mixture of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and sodium polystyrene sulfonate aqueous solution at a volume ratio of 1.2:1 onto the anode and then heat-annealing it.

[0046] The TPPO buried interface modification layer 30 is prepared by spin-coating a solution of triphenylphosphine oxide (TPPO) dissolved in dimethyl sulfoxide (DMSO) onto the modified hole transport layer.

[0047] The all-inorganic tin-based perovskite luminescent layer 40 was prepared by spin-coating a perovskite precursor solution onto a TPPO buried substrate interface modification layer and then thermally annealing. The perovskite precursor solution was prepared by dissolving CsI, SnI2, and SnCl2 in DMSO solvent. CsI and total Sn... 2+ The molar ratio is 1:1, SnCl2 accounts for 10 mol% of the total tin source, and tin powder accounting for 10% of the total tin source mass is added;

[0048] The post-treatment layer 50 is prepared by spin-coating a solution of 2,7-bis(diphenylphosphine)-9,9'-spirodifluorene (SPPO13) dissolved in chlorobenzene onto the perovskite luminescent layer.

[0049] In some embodiments, the anode 10 is a conductive glass substrate (such as a conductive ITO substrate), which is ultrasonically cleaned for 15 minutes each with glass cleaning solution, deionized water and anhydrous ethanol before use, then dried with nitrogen and treated in a plasma cleaner for 7 minutes. The anode conductive ITO substrate has a thickness of 0.7 mm, a size of 1.6 cm × 1.6 cm, a light transmittance of ≥94%, a work function of 4.6 eV, and a resistance of 15 Ω / m2.

[0050] In some embodiments, the electron transport layer 60 is an organic electron transport material B3PYMPM (2,4,6-tris(3-(pyridin-3-yl)phenyl)-1,3,5-triazine).

[0051] In some embodiments, the electron injection layer 70 is lithium fluoride (LiF).

[0052] In some embodiments, the cathode 80 is made of aluminum (Al).

[0053] In some embodiments, the perovskite light-emitting layer is a perovskite thin film.

[0054] Figure 2aThis application provides a method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification. This method is used to fabricate... Figure 1 The diagram shows a high-efficiency, all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification. (Example:) Figure 2a As shown, the preparation method includes:

[0055] S11. CsI, SnI2, and SnCl2 are dissolved in dimethyl sulfoxide (DMSO) solvent, wherein CsI reacts with the total Sn. 2+ The molar ratio of SnCl2 to 10 mol% of the total tin source was 1:1, and tin powder accounting for 10% of the total tin source mass was added to prepare a perovskite precursor solution.

[0056] Understandably, the perovskite precursor solution can be prepared by adding CsI (65 mg), SnI2 (93 mg), SnCl2 (4.7 mg), and tin powder (9.8 mg) to 1 mL of dimethyl sulfoxide (DMSO) solvent, placing it under a nitrogen atmosphere, and stirring at room temperature using a magnetic stirrer with a magnetic stir bar for no less than 9 hours until a uniform and transparent solution is formed, thus obtaining the perovskite precursor solution.

[0057] S12. A modified hole transport layer solution is prepared by mixing poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and sodium polystyrene sulfonate aqueous solution at a volume ratio of 1.2:1.

[0058] S13. Dissolve 2,7-bis(diphenyloxyphosphine)-9,9'-spirodifluorene in chlorobenzene solvent to form a post-treatment solvent.

[0059] S14. Dissolve triphenylphosphine oxide (TPPO) in DMSO solvent to form a buried interface modification layer solution.

[0060] Understandably, the chemical structural formula and ball-and-stick model of TPPO are similar. Figure 2b As shown.

[0061] S15. A modified hole transport layer, a TPPO buried interface modification layer, a perovskite luminescent layer, and a post-treatment layer are sequentially formed on the anode, wherein: the modified hole transport layer is formed by spin-coating a modified hole transport layer solution onto the anode and annealing; the TPPO buried interface modification layer is formed by spin-coating a buried interface modification layer solution onto the modified hole transport layer; the perovskite luminescent layer is formed by spin-coating a perovskite precursor solution onto the TPPO buried interface modification layer and thermally annealing; and the post-treatment layer is formed by spin-coating a post-treatment solvent onto the perovskite luminescent layer.

[0062] S16. An electron transport layer, an electron injection layer, and a cathode are sequentially deposited on the post-processing layer to obtain an all-inorganic tin-based perovskite light-emitting diode.

[0063] In some embodiments, Sn in the perovskite precursor solution 2+ The concentration of tin powder is 0.25 mol / L, the amount of tin powder added is 10% of the total tin source mass, and the perovskite precursor solution is stirred at 25°C for no less than 9 hours.

[0064] In some embodiments, the concentration of sodium polystyrene sulfonate in the modified hole transport layer solution is 50 mg / mL.

[0065] In some embodiments, the concentration of the post-treatment solvent is 4 mg / mL.

[0066] In some embodiments, the concentration of TPPO in the subsurface interface modification layer solution is 4 mg / mL.

[0067] In some embodiments, the modified hole transport layer solution is spin-coated onto the anode at 4000 rpm for 40 seconds and then annealed at 150°C for 15 minutes.

[0068] In some embodiments, the modified hole transport layer is annealed at 110°C for 5 minutes, and then a substrate interface modification layer solution is spin-coated onto it at 2000 rpm for 60 seconds.

[0069] In some embodiments, the perovskite precursor solution is spin-coated onto the TPPO buried interface modification layer at a speed of 4000 rpm for 60 seconds. During the spin-coating process, 500 μL of chlorobenzene is added dropwise as an anti-solvent at the 38th second. The solution is then immediately transferred to a hot plate at the end of the spin-coating process and annealed at 110°C for 10 minutes.

[0070] In some embodiments, the post-treatment solvent is spin-coated onto the perovskite luminescent layer at a speed of 8000 rpm for 30 seconds.

[0071] In some embodiments, the preparation of the anode includes the following steps:

[0072] The conductive ITO substrate was ultrasonically cleaned sequentially with glass cleaning solution, deionized water and anhydrous ethanol for 15 minutes. After being removed and dried with nitrogen, it was then placed in a plasma cleaner for 7 minutes to obtain the anode.

[0073] It can be understood that the specific process for fabricating the high-efficiency all-inorganic tin-based perovskite light-emitting diode device in the embodiments of this application is as follows:

[0074] (1) First, scrub the surface of the conductive substrate ITO with glass cleaning solution, then rinse it with deionized water, then rinse the ITO surface with anhydrous ethanol, and finally place the conductive substrate ITO in anhydrous ethanol solution for ultrasonic treatment for 15 minutes, and blow the residual solvent on the ITO surface with nitrogen.

[0075] (2) Next, the conductive substrate ITO substrate that was cleaned in step (1) was plasma treated for 7 minutes and then quickly transferred to an air glove box to prepare the hole transport layer.

[0076] (3) The modified hole transport layer (sodium polystyrene sulfonate:PEDOT:PSS=1.2:1) is statically coated onto the conductive substrate ITO substrate that was cleaned in step (2) and the entire substrate is covered. The spin coating conditions are set to 4000rpm / 40s and the annealing conditions are 150℃ / 15min.

[0077] (4) Transfer the conductive ITO substrate containing the modified hole transport layer prepared in step (3) to a nitrogen-filled glove box for spin coating of the TPPO buried interface modification layer. Anneal the conductive ITO substrate containing the modified hole transport layer at 110°C for 5 min, and then spin coat the buried interface modification layer solution. The spin coating conditions for the TPPO buried interface modification layer are 2000 rpm / 60 s.

[0078] (5) Use a pipette to take 50 μL of perovskite precursor solution and spin coat it onto the modified hole transport layer. Set the spin coating conditions to 4000 rpm / 60 s. At 38 s, use a pipette to quickly add 500 μL of antisolvent chlorobenzene. Spin coating is completed at 60 s. Then perform annealing treatment. The annealing conditions are: 110 ℃ / 10 min.

[0079] (6) After the perovskite light-emitting layer obtained in step (5), i.e. the perovskite film, is annealed and cooled down, post-processing is performed. 50 μL of SPPO13 chlorobenzene solution is taken with a pipette and dynamically coated onto the perovskite film. The spin coating conditions are 8000 rpm / 30s.

[0080] (7) An electron transport layer B3PYMPM (45nm), an electron injection layer LiF (2nm), and an electrode Al (120nm) are sequentially deposited on the post-processing layer in step (6). The schematic diagram of the device structure is shown below. Figure 1 As shown.

[0081] The components of the light-emitting diode in the original example are the same as those in the embodiments of this application, except that the modified perovskite light-emitting layer is different. The modified perovskite light-emitting layer refers to the TPPO buried interface modification layer introduced between the modified hole transport layer and the perovskite light-emitting layer.

[0082] The specific preparation method of the solution in the original example is as follows:

[0083] Preparation of perovskite precursor solution: CsI (65 mg), SnI2 (93 mg), SnCl2 (4.7 mg), and tin powder (5 mg) were dissolved in 1 mL of DMSO solvent and stirred overnight at room temperature under a nitrogen atmosphere.

[0084] The specific process for fabricating the high-efficiency all-inorganic tin-based perovskite light-emitting diode device in the original example is as follows:

[0085] 1) First, scrub the surface of the conductive ITO substrate with glass cleaning solution, then rinse it with deionized water, then rinse the ITO surface with anhydrous ethanol, and finally sonicate the ITO in anhydrous ethanol solution for 15 minutes. Blow dry the residual solvent on the ITO surface with nitrogen gas;

[0086] 2) Next, the cleaned conductive substrate ITO substrate from step 1) is plasma treated for 7 minutes and then quickly transferred to an air glove box to prepare the hole transport layer.

[0087] 3) The modified hole transport layer (sodium polystyrene sulfonate:PEDOT:PSS=1.2:1) was statically coated onto the ITO substrate and covered the entire substrate. The spin coating conditions were set to 4000 rpm / 40s and the annealing conditions were set to 150℃ / 15min.

[0088] 4) Transfer the conductive ITO substrate containing the modified hole transport layer prepared in step 3) to a nitrogen-filled glove box for spin coating of the perovskite light-emitting layer. Use a pipette to take 50 μL of the original perovskite precursor solution and spin coat it onto the modified hole transport layer. Set the spin coating conditions to 4000 rpm / 60 s. At 38 s, use a pipette to quickly drop 500 μL of the anti-solvent chlorobenzene. After spin coating is completed at 60 s, perform annealing treatment. The annealing conditions are: 110 ℃ / 10 min.

[0089] 5) After the perovskite film obtained in step 4) has been annealed and cooled down, post-processing is performed. Use a pipette to take 50 μL of SPPO13 chlorobenzene solution and spin-coat it onto the perovskite film. The spin-coating conditions are 8000 rpm / 30s.

[0090] 6) Sequentially deposit an electron transport layer B3PYMPM (45nm), an electron injection layer LiF (2nm), and an electrode Al (120nm) onto the thin film from step 5). A schematic diagram of the device structure is shown below. Figure 2c As shown.

[0091] The photoelectric performance of the light-emitting diode devices obtained in the examples and the original examples was tested. The light-emitting area of ​​the devices was 0.04 mm2.

[0092] like Figure 2d and Figure 2e As shown, the photoelectric performance of the light-emitting diodes of the present application embodiments and the original examples is illustrated. Compared with the light-emitting diode of the original example, the embodiments exhibit a higher radiance under the same voltage driving condition, and the external quantum efficiency of the embodiments is significantly improved compared with the original example. The electroluminescence peak shows no significant shift. Using an efficient and simple method, triphenylphosphine oxide (TPPO) is introduced as a buried interface modification layer between the hole transport layer and the perovskite light-emitting layer, achieving interface modification of the hole transport layer through a simple process. The above optimization method significantly improves the performance indicators of perovskite light-emitting diodes, laying a solid foundation for the commercial application of all-inorganic tin-based perovskite devices.

[0093] The above description is merely an optional embodiment of this disclosure and is 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 high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification, characterized in that, The diode comprises, in sequence, an anode, a modified hole transport layer, a TPPO buried interface modification layer, a perovskite light-emitting layer, a post-processing layer, an electron transport layer, an electron injection layer, and a cathode. The modified hole transport layer is formed by spin-coating a mixture of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and sodium polystyrene sulfonate aqueous solution at a volume ratio of 1.2:1 onto the anode and then heat-annealing it. The TPPO buried interface modification layer is prepared by spin-coating a solution of triphenylphosphine oxide (TPPO) dissolved in dimethyl sulfoxide (DMSO) onto the modified hole transport layer. The all-inorganic tin-based perovskite luminescent layer is prepared by spin-coating a perovskite precursor solution onto the TPPO buried substrate interface modification layer and then thermally annealing. The perovskite precursor solution is prepared by dissolving CsI, SnI2, and SnCl2 in DMSO solvent, wherein CsI and total Sn... 2+ The molar ratio is 1:1, SnCl2 accounts for 10 mol% of the total tin source, and tin powder accounting for 10% of the total tin source mass is added; The post-treatment layer is prepared by spin-coating a solution of 2,7-bis(diphenylphosphine)-9,9'-spirodifluorene dissolved in chlorobenzene onto the perovskite luminescent layer.

2. A method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification, characterized in that, include: CsI, SnI2, and SnCl2 were dissolved in dimethyl sulfoxide (DMSO) solvent, wherein CsI reacted with the total Sn. 2+ The molar ratio of SnCl2 to 10 mol% of the total tin source was 1:1, and tin powder accounting for 10% of the total tin source mass was added to prepare a perovskite precursor solution. A modified hole transport layer solution was prepared by mixing poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) with an aqueous solution of sodium polystyrene sulfonate at a volume ratio of 1.2:

1. 2,7-bis(diphenylphosphine)-9,9'-spirodifluorene was dissolved in chlorobenzene to form a post-treatment solvent; Triphenylphosphine oxide (TPPO) was dissolved in DMSO solvent to form a buried interface modification layer solution; A modified hole transport layer, a TPPO buried interface modification layer, a perovskite luminescent layer, and a post-treatment layer are sequentially formed on the anode, wherein: The modified hole transport layer is formed by spin-coating the modified hole transport layer solution onto the anode and then annealing. The TPPO subsurface interface modification layer is formed by spin-coating the subsurface interface modification layer solution onto the modified hole transport layer; The perovskite luminescent layer is formed by spin-coating the perovskite precursor solution onto the TPPO buried interface modification layer and then thermally annealing. The post-treatment layer is formed by spin-coating the post-treatment solvent onto the perovskite luminescent layer; An electron transport layer, an electron injection layer, and a cathode are sequentially deposited on the post-processing layer to obtain the all-inorganic tin-based perovskite light-emitting diode.

3. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, Sn in perovskite precursor solution 2+ The concentration of the tin powder is 0.25 mol / L, the amount of tin powder added is 10% of the total tin source mass, and the perovskite precursor solution is stirred at 25°C for no less than 9 hours.

4. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, The concentration of the sodium polystyrene sulfonate aqueous solution in the modified hole transport layer solution is 50 mg / mL.

5. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, The concentration of the post-treatment solvent is 4 mg / mL.

6. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, The concentration of TPPO in the substrate interface modification layer solution is 4 mg / mL.

7. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, The modified hole transport layer solution was spin-coated onto the anode at 4000 rpm for 40 seconds and then annealed at 150°C for 15 minutes.

8. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, The modified hole transport layer was annealed at 110°C for 5 minutes, and then the buried interface modification layer solution was spin-coated onto it at 2000 rpm for 60 seconds.

9. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, The perovskite precursor solution was spin-coated onto the TPPO buried interface modification layer at a speed of 4000 rpm for 60 seconds. During the spin-coating process, 500 μL of chlorobenzene was added dropwise as an anti-solvent at the 38th second. The solution was immediately transferred to a hot plate at the end of the spin-coating process and annealed at 110°C for 10 minutes.

10. The method for fabricating a high-efficiency all-inorganic tin-based perovskite light-emitting diode based on TPPO interface modification as described in claim 2, characterized in that, The post-treatment solvent was spin-coated onto the perovskite luminescent layer at a speed of 8000 rpm for 30 seconds.

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