A research method for preparing a high-performance quasi-two-dimensional blue light PeLED device

Abstract

The application provides a research method for preparing a high-performance quasi-two-dimensional blue light PeLED device, and belongs to the technical field of display, and comprises the following steps: establishing a theoretical model, simulating the crystallization orientation of a blue light quasi-two-dimensional perovskite film, preparing a quasi-two-dimensional blue light perovskite solution, exploring the influence of different preheating temperatures, exploring the influence of hot injection of an anti-solvent, using a PIN structure and using different hole transport layers to study the influence of the transport layer interface of perovskite growth on the crystallization orientation of quasi-two-dimensional blue light perovskite, and characterizing the photoelectric properties of the quasi-two-dimensional blue light perovskite after regulation and the performance of a blue light perovskite light-emitting diode prepared therefrom. The application deeply analyzes the influence of different conditions on crystal growth in the crystallization process, obtains an optimal solution for vertical growth of quasi-two-dimensional blue light perovskite crystals, constructs crystal orientation perpendicular to a substrate, and further improves the charge transport of quasi-two-dimensional blue light perovskite.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of display, and particularly relates to a research method for preparing a high-performance quasi-two-dimensional blue light PeLED device. BACKGROUND

[0002] Most of the organic ligands of quasi-two-dimensional perovskites contain saturated long chains, which limit the charge transport between inorganic frameworks. Building crystal orientation perpendicular to the substrate helps to improve the charge transport of quasi-two-dimensional perovskites, but the growth mechanism and control process thereof still lack relevant research.

[0003] The substrate temperature plays a crucial role in nucleation and growth. When the temperature of the substrate is higher than the crystallization temperature of the perovskite phase, there is no intermediate phase conversion stage to the perovskite crystal, which directly leads to the formation of larger grain boundaries of the perovskite crystal, which is not conducive to the exciton radiative recombination of the perovskite light-emitting diode.

[0004] Therefore, it is urgent to find a technical means to solve the above problems and prepare a high-efficiency and stable blue light PeLED device. SUMMARY

[0005] The application provides a preparation method of a research method for preparing a high-performance quasi-two-dimensional blue light PeLED device, so as to solve the problems of lack of research on the growth mechanism and control process orientation of the vertical crystal and larger grain boundaries of the perovskite crystal in the prior art.

[0006] In order to achieve the above purpose, the technical scheme adopted by the application is as follows:

[0007] A research method for preparing a high-performance quasi-two-dimensional blue light PeLED device, comprising the following steps:

[0008] Step 1: establishing a theoretical model of perovskite vertical growth;

[0009] Step 2: simulating through the established theoretical model to obtain the influence data of the substrate temperature on the crystalline orientation of the blue light quasi-two-dimensional perovskite film in different film forming processes;

[0010] Step 3: preparing quasi-two-dimensional blue light perovskite solutions with different raw material ratios;

[0011] Step 4: setting a gradient preheating temperature for the substrate to obtain the crystallization condition and crystal orientation data of the quasi-two-dimensional blue light perovskite solution under different substrate preheating temperatures;

[0012] Step 5: setting a gradient for the temperature of the anti-solvent to obtain the crystalline orientation data of the quasi-two-dimensional blue light perovskite solution under different temperature anti-solvent hot injection;

[0013] Step 6: Obtain the orientation data of quasi-two-dimensional blue light perovskite crystals under different hole transport layers by using PIN device mechanism with different hole transport layers;

[0014] Step 7: Characterize the photoelectric properties of the quasi-two-dimensional blue light perovskite crystals obtained after the regulation in steps 3 to 6 and the performance of the blue light perovskite light-emitting diode prepared therefrom, and analyze the reasons for the performance improvement of the blue light perovskite light-emitting diode due to vertical growth from the perspectives of defect states, energy levels, and charge transport;

[0015] Step 8: Adopt an appropriate blue light device preparation process according to the characteristics of the quasi-two-dimensional blue light perovskite material, including selecting different P-type semiconductors and N-type semiconductors as hole and electron transport layers, respectively;

[0016] Step 9: Finally, prepare a blue light device combined with the quasi-two-dimensional blue light perovskite thin film, test the current density-voltage-brightness and electroluminescence spectrum of the blue light device, analyze the performance of the blue light device, and adjust the structure and process technology of the blue light device based on the simulation and test results.

[0017] Preferably, step 1 adopts the island growth model, perovskite interface growth model, and carrier transport model of polycrystalline thin film crystallization to establish a kinetic model of vertical growth of inorganic crystals in quasi-two-dimensional blue light perovskite.

[0018] Preferably, the specific steps of step 2 are as follows:

[0019] Step 2.1: Obtain the optical and electrical properties of the quasi-two-dimensional blue light perovskite thin film through simulation based on the established kinetic model, and perform optical simulation on the blue light PeLED;

[0020] Step 2.2: Further simulate the influence of substrate temperature on the crystalline orientation of the quasi-two-dimensional blue light perovskite thin film in different film formation processes based on the results obtained from the optical simulation.

[0021] Preferably, the specific steps of step 3 are as follows:

[0022] Step 3.1: Select PbBr2, MABr, CsBr, and PEABr materials as raw materials, and select N,N-dimethylacetamide and dimethyl sulfoxide as solvents;

[0023] Step 3.2: Dissolve the raw materials in two solvents or a mixed solvent of the two solvents in different proportions to prepare a variety of quasi-two-dimensional blue light perovskite solutions with different raw material ratios.

[0024] Preferably, the specific steps of step 4 are as follows:

[0025] Step 4.1: Set a gradient for the preheating temperature of the substrate, from room temperature to 180°C, with every 5°C as a sample.

[0026] Step 4.2: The crystallization condition and crystal orientation of the quasi-two-dimensional blue light perovskite solution with different raw material ratios and different preheating temperatures are characterized by using scanning electron microscopy and X-ray diffraction technology.

[0027] Preferably, the specific steps of step 5 are as follows:

[0028] Step 5.1: Determine the boiling point of the different anti-solvents to be used, and set the temperature of the anti-solvent in a gradient from room temperature to boiling point, every 5℃ as a sample;

[0029] Step 5.2: The crystallization condition and crystal orientation of the quasi-two-dimensional blue light perovskite solution with different raw material ratios and different preheating temperatures are characterized by using scanning electron microscopy and X-ray diffraction technology.

[0030] Preferably, the specific steps of step 6 are as follows:

[0031] Step 6.1: Use oxide, small molecule, and polymer as hole transport layer, respectively;

[0032] Step 6.2: Analyze the influence of film wettability, functional groups, roughness, and microstructure of different materials of hole transport layer on crystalline orientation, and determine the conditions for obtaining vertical growth.

[0033] Preferably, the specific steps of step 7 are as follows:

[0034] Step 7.1: Study the electronic energy level of different surface depths of quasi-two-dimensional blue light perovskite by ion etching method;

[0035] Step 7.2: Prepare single charge transport device, and analyze the mobility of vertical growth blue light quasi-two-dimensional perovskite film and control film by using space charge limited current model;

[0036] Step 7.3: Perform steady-state and transient luminescence spectrum test on the blue light quasi-two-dimensional perovskite film grown vertically, modify the wettability of the lower interface buffer layer of the quasi-two-dimensional blue light perovskite, further adjust the grain boundary size of the quasi-two-dimensional blue light perovskite, and enhance the exciton radiative recombination of the quasi-two-dimensional blue light perovskite;

[0037] Step 7.4: Study the exciton radiative and non-radiative recombination processes of the blue light quasi-two-dimensional perovskite film by comparing the luminescence intensity, luminescence peak position, and luminescence lifetime characteristics, and analyze the exciton lifetime condition in the quasi-two-dimensional blue light perovskite;

[0038] Step 7.5: Modify the wettability of the lower interface buffer layer of the quasi-two-dimensional blue light perovskite, further adjust the grain boundary size of the quasi-two-dimensional blue light perovskite, and enhance the exciton radiative recombination of the quasi-two-dimensional blue light perovskite.

[0039] Compared with the prior art, the application has the beneficial effects that:

[0040] 1、The application deeply analyzes the influence of different conditions in the crystallization process on the growth of crystals, obtains the optimal solution of quasi-two-dimensional blue light perovskite crystal vertical growth, constructs the crystal orientation perpendicular to the substrate, and further improves the charge transport of quasi-two-dimensional blue light perovskite.

[0041] 2、The application analyzes the reasons for the performance improvement of the vertical growth of the blue light device from the angles of defect state, energy level, charge transport, studies the exciton radiation and non-radiation recombination process of the quasi-two-dimensional blue light perovskite film, analyzes the exciton lifetime status in the quasi-two-dimensional blue light perovskite, simultaneously modifies the wettability of the lower interface buffer layer of the quasi-two-dimensional blue light perovskite, further adjusts the grain boundary size of the quasi-two-dimensional blue light perovskite, so as to enhance the exciton radiation recombination of the quasi-two-dimensional blue light perovskite, according to the material characteristics, selects different P-type semiconductor and N-type semiconductor materials as the hole and electron transport layer respectively, so as to balance the hole and electron transport capacity of the device, widen the light emitting area, and prepare a high-efficiency and stable blue light PeLEDs device. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is the flowchart of the application;

[0043] Figure 2 is the structure diagram of the quasi-two-dimensional blue light PeLEDs device;

[0044] Figure 3 is the actual picture of the quasi-two-dimensional blue light PeLEDs under bias light emission. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme in the embodiments of the application will be described clearly and completely below in conjunction with the drawings in the embodiments of the application. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. The components of the embodiments of the application described and shown in the drawings can be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the application without creative labor are within the scope of protection of the application.

[0047] The specific embodiments of the application will be described in detail below in conjunction with the drawings.

[0048] Embodiment 1:

[0049] A research method for preparing a high-performance quasi-two-dimensional blue light PeLED device, as shown in Figure 1 comprises the following steps:

[0050] Step 1: Establish a theoretical model for the vertical growth of perovskite, specifically: adopt the island growth model of polycrystalline thin film crystallization, the perovskite interface growth model and the carrier transport model, and establish a kinetic model for the vertical growth of inorganic crystals in quasi-two-dimensional blue light perovskite;

[0051] Step 2: Simulate the established theoretical model to obtain the influence data of substrate temperature on the crystalline orientation of blue light quasi-two-dimensional perovskite thin film in different film forming processes, specifically including the following steps:

[0052] Step 2.1: According to the established kinetic model, the optical and electrical properties of the blue light quasi-two-dimensional perovskite thin film are obtained by simulation, and the optical simulation of the blue light PeLED is carried out;

[0053] Step 2.2: Further simulate the influence of substrate temperature on the crystalline orientation of blue light quasi-two-dimensional perovskite thin film in different film forming processes according to the results obtained by optical simulation;

[0054] Step 3: Prepare quasi-two-dimensional blue light perovskite solutions with different raw material ratios, specifically including the following steps:

[0055] Step 3.1: Select PbBr2, MABr, CsBr and PEABr materials as raw materials, and select N,N dimethylacetamide and dimethyl sulfoxide as solvents;

[0056] Step 3.2: Dissolve the raw materials in two solvents or mixed solvents of the two solvents according to different ratios to prepare a plurality of quasi-two-dimensional blue light perovskite solutions with different raw material ratios;

[0057] Step 4: Set a gradient preheating temperature for the substrate to obtain the crystallization condition and crystal orientation data of the quasi-two-dimensional blue light perovskite solution under different substrate preheating temperatures, specifically including the following steps:

[0058] Step 4.1: Set the preheating temperature of the substrate in a gradient from room temperature to 180℃, and take every 5℃ as a sample;

[0059] Step 4.2: Use scanning electron microscopy and X-ray diffraction technology to characterize the crystallization condition and crystal orientation of the quasi-two-dimensional blue light perovskite solution with different raw material ratios under different preheating temperatures;

[0060] Step 5: Gradient set the temperature of the anti-solvent to obtain the crystalline orientation data of the quasi-two-dimensional blue light perovskite solution under the thermal injection of the anti-solvent at different temperatures, specifically including the following steps:

[0061] Step 5.1: Determine the boiling point of the different anti-solvents to be used, and set the temperature of the anti-solvent in a gradient from room temperature to boiling point, with each interval of 5°C as a sample;

[0062] Step 5.2: Use scanning electron microscopy and X-ray diffraction techniques to characterize the crystallization conditions and crystal orientation of the quasi-two-dimensional blue light perovskite solution with different preheating temperatures and different raw material ratios;

[0063] Step 6: Use PIN-type device mechanism with different materials of hole transport layer, obtain the orientation data of quasi-two-dimensional blue light perovskite crystal under different materials of hole transport layer, including the following steps:

[0064] Step 6.1: Use oxide, small molecule, and polymer as hole transport layer respectively;

[0065] Step 6.2: Analyze the influence of film wettability, functional groups, roughness, and microstructure of different materials of hole transport layer on crystal orientation, and determine the conditions for obtaining vertical growth;

[0066] Step 7: Characterize the photoelectric properties of quasi-two-dimensional blue light perovskite and the performance of blue light perovskite light-emitting diode prepared based on the regulation in steps 3 to 6, analyze the reasons for the performance improvement of blue light perovskite light-emitting diode by vertical growth from the perspectives of defect state, energy level, and charge transport, including the following steps:

[0067] Step 7.1: Use ion etching method to study the electronic energy levels of different surface depths of quasi-two-dimensional blue light perovskite;

[0068] Step 7.2: Prepare single charge transport device, and analyze the mobility of vertical growth blue light quasi-two-dimensional perovskite film and control film using space charge limited current model;

[0069] Step 7.3: Perform steady-state and transient luminescence spectrum test on the blue light quasi-two-dimensional perovskite film by vertical growth, modify the wettability of the lower interface buffer layer of quasi-two-dimensional blue light perovskite, further adjust the grain boundary size of quasi-two-dimensional blue light perovskite, and enhance the exciton radiative recombination of quasi-two-dimensional blue light perovskite;

[0070] Step 7.4: By comparing the luminescence intensity, luminescence peak position, and luminescence lifetime characteristics, study the exciton radiative and non-radiative recombination processes of blue light quasi-two-dimensional perovskite film, and analyze the exciton lifetime status in quasi-two-dimensional blue light perovskite;

[0071] Step 7.5: Modify the wettability of the lower interface buffer layer of quasi-two-dimensional blue light perovskite, further adjust the grain boundary size of quasi-two-dimensional blue light perovskite, and enhance the exciton radiative recombination of quasi-two-dimensional blue light perovskite;

[0072] Step 8: According to the characteristics of quasi-two-dimensional blue light perovskite material, an adaptive blue light device preparation process is adopted, including screening different P-type semiconductor and N-type semiconductor materials as hole and electron transport layers respectively;

[0073] Step 9: Finally, a blue light device is prepared combined with a quasi-two-dimensional blue light perovskite film, the current density-voltage-brightness and electroluminescence spectrum of the blue light device are tested, the performance of the blue light device is analyzed, and the structure of the blue light device and the process technology are adjusted combined with simulation and test results.

[0074] In this embodiment, the application deeply analyzes the influence of different conditions on crystal growth in the crystallization process, obtains the optimal solution for the vertical growth of quasi-two-dimensional blue light perovskite crystals, constructs crystal orientation perpendicular to the substrate, and further improves the charge transport of quasi-two-dimensional blue light perovskite. The application analyzes the reasons for the performance improvement of the blue light device by vertical growth from the angles of defect state, energy level, and charge transport, studies the exciton radiation and non-radiation recombination process of the quasi-two-dimensional blue light perovskite film, analyzes the exciton lifetime of the quasi-two-dimensional blue light perovskite, and further adjusts the grain boundary size of the quasi-two-dimensional blue light perovskite to enhance the exciton radiation recombination of the quasi-two-dimensional blue light perovskite. According to the material characteristics, different P-type semiconductor and N-type semiconductor materials are selected as hole and electron transport layers respectively to balance the hole and electron transport capabilities of the device, widen the light emitting area, and prepare a high-efficiency and stable blue light PeLEDs device.

[0075] Figure 2 The structure diagram of the quasi-two-dimensional blue light PeLEDs device developed is shown in Figure 1, and Figure 3 The actual photo of the quasi-two-dimensional blue light PeLEDs under bias is shown in Figure 2. The application includes establishing a theoretical model, simulating the crystalline orientation of the quasi-two-dimensional blue light perovskite film, preparing a quasi-two-dimensional blue light perovskite solution, exploring the influence of different preheating temperatures, exploring the influence of thermal injection of anti-solvent, using a PIN structure and different hole transport layers to study the influence of the transport layer interface of perovskite growth on the crystalline orientation of quasi-two-dimensional blue light perovskite, and characterizing the photoelectric properties of the quasi-two-dimensional blue light perovskite after regulation and the performance of the blue light perovskite light-emitting diode prepared therefrom.

[0076] The application innovatively adopts an island growth model of polycrystalline thin film crystallization, a perovskite interface growth model, and a carrier transport model to establish a kinetics model of vertical growth of inorganic crystals in quasi-two-dimensional blue light perovskite. Through interface regulation and process optimization, the vertical growth of quasi-two-dimensional blue light perovskite is effectively regulated, and the efficient transport of carriers at the interface of the functional layer and in the light-emitting layer is promoted. The preparation process of quasi-two-dimensional blue light perovskite vertical growth is regulated, and a high-performance blue light PeLEDs device is developed.

[0077] Finally, it should be noted that: the above examples are only the preferred embodiments of the present application, in order to illustrate the technical solutions of the present application, rather than limit, of course, is not to limit the scope of the patent of the present application. Although the present application is described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still be modified to the technical solutions recorded in the foregoing examples, or part or all of the technical features are replaced by the equivalent; and these modifications or replacements, do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application; that is to say, but whatever in the main design idea and spirit of the present application makes no substantive sense of the change or polish, the technical problem solved is still consistent with the present application, should be included in the protection scope of the present application; in addition, the technical solutions of the present application are directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A research method for preparing high-performance quasi-two-dimensional blue light PeLED devices, comprising the following steps: Step 1: Establish a theoretical model for the vertical growth of perovskite; Step 2: Obtain the influence data of substrate temperature on the crystalline orientation of blue light quasi-two-dimensional perovskite film in different film formation processes through simulation based on the established theoretical model; Step 3: Prepare quasi-two-dimensional blue light perovskite solutions with different raw material ratios; Step 4: Set a gradient preheating temperature for the substrate, and obtain the crystallization condition and crystal orientation data of the quasi-two-dimensional blue light perovskite solution under different substrate preheating temperatures; Step 5: Set a gradient for the temperature of the anti-solvent, and obtain the crystalline orientation data of the quasi-two-dimensional blue light perovskite solution under different temperature anti-solvents; Step 6: Obtain the orientation data of quasi-two-dimensional blue light perovskite crystals under different hole transport layer materials using PIN-type device mechanisms with different hole transport layer materials; Step 7: Characterize the photoelectric properties of the quasi-two-dimensional blue light perovskite crystals obtained after the regulation in steps 3 to 6 and the performance of the blue light perovskite light-emitting diodes prepared therefrom, and analyze the reasons for the performance improvement of the blue light perovskite light-emitting diodes due to vertical growth from the perspectives of defect states, energy levels, and charge transport; Step 8: Adopt an appropriate blue light device preparation process based on the characteristics of the quasi-two-dimensional blue light perovskite material, including selecting different P-type semiconductors and N-type semiconductors as hole and electron transport layers, respectively; Step 9: Finally, prepare blue light devices combined with quasi-two-dimensional blue light perovskite films, test the current density-voltage-brightness and electroluminescence spectrum of the blue light devices, analyze the performance of the blue light devices, and adjust the structure and reengineering process technology of the blue light devices based on the simulation and test results; The step 1 adopts an island growth model of polycrystalline thin film crystallization, a perovskite interface growth model, and a carrier transport model to establish a kinetic model for the vertical growth of inorganic crystals in quasi-two-dimensional blue light perovskite; The specific steps of step 2 are as follows, Step 2.1: Obtain the optical and electrical properties of blue light quasi-two-dimensional perovskite thin films through simulation based on the established kinetic model, and perform optical simulation on blue light PeLED; Step 2.2: Further simulate the influence of substrate temperature on the crystalline orientation of blue light quasi-two-dimensional perovskite thin films in different film formation processes based on the results obtained from optical simulation; The specific steps of step 3 are as follows, Step 3.1: Select PbBr2, MABr, CsBr, and PEABr materials as raw materials, and select N,N-dimethylacetamide and dimethyl sulfoxide as solvents; Step 3.2: Dissolve the raw materials in two solvents or a mixed solvent of the two solvents according to different ratios to prepare multiple quasi-two-dimensional blue light perovskite solutions with different raw material ratios.

2. The research method for preparing high-performance quasi-two-dimensional blue light PeLED device according to claim 1, wherein, The specific steps of step 4 are as follows: Step 4.1: Set a gradient for the preheating temperature of the substrate, from room temperature to 180°C, with every 5°C as a sample; Step 4.2: Characterize the crystallization condition and crystal orientation of the quasi-two-dimensional blue light perovskite solution with different raw material ratios at different preheating temperatures using scanning electron microscopy and X-ray diffraction technology.

3. The research method for preparing high-performance quasi-two-dimensional blue light PeLED device according to claim 1, wherein, The specific steps of step 5 are as follows: Step 5.1: Determine the boiling point of the different anti-solvents to be used, and set the temperature of the anti-solvent in a gradient from room temperature to boiling point, every 5℃ as a sample; Step 5.2: Use scanning electron microscopy and X-ray diffraction techniques to characterize the crystallization conditions and crystal orientation of the quasi-two-dimensional blue light perovskite solution with different preheating temperatures and raw material ratios.

4. The research method for preparing high-performance quasi-two-dimensional blue light PeLED device according to claim 1, wherein, The specific steps of step 6 are as follows: Step 6.1: Use oxide, small molecule, and polymer as hole transport layer, respectively; Step 6.2: Analyze the effects of film wettability, functional groups, roughness, and microstructure of different materials of hole transport layer on crystalline orientation, and determine the conditions for obtaining vertical growth.

5. The research method for preparing high-performance quasi-two-dimensional blue light PeLED device according to claim 1, wherein, The specific steps of step 7 are as follows: Step 7.1: Use ion etching method to study the electronic energy level of quasi-two-dimensional blue light perovskite with different surface depths; Step 7.2: Prepare single charge transport devices, and use space charge limited current model to analyze the mobility of vertical growth blue light quasi-two-dimensional perovskite film and control film; Step 7.3: Perform steady-state and transient luminescence spectrum test on the blue light quasi-two-dimensional perovskite film grown vertically, modify the wettability of the lower interface buffer layer of the quasi-two-dimensional blue light perovskite, further adjust the grain boundary size of the quasi-two-dimensional blue light perovskite, and enhance the exciton radiative recombination of the quasi-two-dimensional blue light perovskite; Step 7.4: By comparing the luminescence intensity, luminescence peak position, and luminescence lifetime characteristics, study the exciton radiative and non-radiative recombination processes of the blue light quasi-two-dimensional perovskite film, and analyze the exciton lifetime status in the quasi-two-dimensional blue light perovskite; Step 7.5: Modify the wettability of the lower interface buffer layer of the quasi-two-dimensional blue light perovskite, further adjust the grain boundary size of the quasi-two-dimensional blue light perovskite, and enhance the exciton radiative recombination of the quasi-two-dimensional blue light perovskite.

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