Research method for preparing high-performance quasi-two-dimensional blue-light PeLED device

Abstract

The invention 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 the method comprises the following steps: building a theoretical model, simulating the crystal orientation of a blue light quasi-two-dimensional perovskite thin film, preparing a quasi-two-dimensional blue light perovskite solution, exploring the influence of different preheating temperatures, exploring the influence of a thermal injection anti-solvent, and obtaining a high-performance quasi-two-dimensional blue light PeLED device. A PIN structure and different hole transport layers are adopted to research the influence of a transport layer interface for perovskite growth on the crystallization orientation of the two-dimensional blue-light perovskite, and the photoelectric characteristics of the regulated and controlled quasi-two-dimensional blue-light perovskite and the performance of a blue-light perovskite light-emitting diode prepared from the quasi-two-dimensional blue-light perovskite are represented. According to the method, the influence of different conditions on crystal growth in the crystallization process is deeply analyzed, the optimal solution of vertical growth of the quasi-two-dimensional blue-light perovskite crystal is obtained, crystal orientation perpendicular to the substrate is constructed, and charge transfer of the quasi-two-dimensional blue-light perovskite is further improved.

Description

Technical Field

[0001] The invention belongs to the field of display technology, and in particular relates to a research method for preparing a high-performance quasi-two-dimensional blue light PeLED device. Background Art

[0002] Most of the organic ligands of quasi-two-dimensional perovskites contain saturated long chains, which limit the charge transfer between inorganic frameworks. Constructing a crystal orientation perpendicular to the substrate can help improve the charge transfer of quasi-two-dimensional perovskites, but there is still a lack of relevant research on its growth mechanism and control process.

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

[0004] Therefore, it is urgent to find a technical means to solve the above problems and prepare efficient and stable blue light PeLEDs devices. Summary of the invention

[0005] The present invention proposes a preparation method for a research method of preparing a high-performance quasi-two-dimensional blue light PeLED device to solve the problems in the prior art of lack of research on the growth mechanism and control process orientation of vertical crystals and large grain boundaries of perovskite crystals.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A research method for preparing a high-performance quasi-two-dimensional blue light PeLED device comprises the following steps: Step 1: Establish a theoretical model for vertical growth of perovskite; Step 2: Use the established theoretical model to simulate and obtain data on the effect of substrate temperature on the crystal orientation of blue light quasi-two-dimensional perovskite thin films in different film forming processes; Step 3: preparing quasi-two-dimensional blue light perovskite solutions with different raw material ratios; Step 4: setting a gradient preheating temperature for the substrate to obtain the crystallization state and crystal orientation data of the quasi-two-dimensional blue light perovskite solution at different substrate preheating temperatures; Step 5: Setting the temperature of the antisolvent in a gradient manner to obtain the crystal orientation data of the quasi-two-dimensional blue light perovskite solution under hot injection of antisolvents at different temperatures; Step 6: Using a PIN device structure with hole transport layers of different materials, obtain the orientation data of quasi-two-dimensional blue light perovskite crystals under hole transport layers of different materials; Step 7: Characterize the photoelectric properties of the crystallized quasi-two-dimensional blue light perovskite regulated by steps 3 to 6 and the performance of the blue light perovskite light-emitting diode prepared therefrom, and analyze the reasons why vertical growth improves the performance of the blue light perovskite light-emitting diode from the perspectives of defect states, energy levels, and charge transfer; Step 8: Adopting an adapted blue light device preparation process according to the characteristics of the quasi-two-dimensional blue light perovskite material, including screening different P-type semiconductor and N-type semiconductor materials as hole and electron transport layers respectively; Step 9: Finally, prepare a blue light device by combining the blue light quasi-two-dimensional perovskite 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.

[0007] Preferably, step 1 adopts the island growth model of polycrystalline thin film crystallization, the perovskite interface growth model and the carrier transport model to establish a kinetic model of vertical growth of inorganic crystals in quasi-two-dimensional blue light perovskite.

[0008] Preferably, the specific steps of step 2 are as follows: Step 2.1: According to the established kinetic model, the optical and electrical properties of the blue light quasi-two-dimensional perovskite film are obtained through simulation, and the optical simulation of the blue light PeLED is performed; Step 2.2: Based on the results obtained from optical simulation, further simulate the effect of substrate temperature on the crystal orientation of blue light quasi-two-dimensional perovskite films in different film forming processes.

[0009] Preferably, the specific steps of step 3 are as follows: Step 3.1: PbBr2, MABr, CsBr, PEABr materials are selected as raw materials, and N, N-dimethylacetamide and dimethyl sulfoxide are selected as solvents; Step 3.2: Dissolve the raw materials in two solvents or a mixed solvent of the two solvents in different ratios to prepare quasi-two-dimensional blue light perovskite solutions with a variety of different raw material ratios.

[0010] Preferably, the specific steps of step 4 are as follows: Step 4.1: Set the preheating temperature of the substrate in a gradient from room temperature to 180°C, with each 5°C as a sample; Step 4.2: Use scanning electron microscopy and X-ray diffraction technology to characterize the crystallization state and crystal orientation of quasi-two-dimensional blue light perovskite solutions with different raw material ratios at different preheating temperatures.

[0011] Preferably, the specific steps of step 5 are as follows: Step 5.1: Determine the boiling points of 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; Step 5.2: Use scanning electron microscopy and X-ray diffraction technology to characterize the crystallization state and crystal orientation of quasi-two-dimensional blue light perovskite solutions with different raw material ratios at different preheating temperatures.

[0012] Preferably, the specific steps of step 6 are as follows: Step 6.1: using oxides, small molecules, and polymers as hole transport layers respectively; Step 6.2: Analyze the effects of thin film wettability, functional groups, roughness, and microstructure of hole transport layers of different materials on crystal orientation to determine the conditions for obtaining vertical growth.

[0013] Preferably, the specific steps of step 7 are as follows: Step 7.1: Using ion etching, study the electronic energy levels at different surface depths of the quasi-two-dimensional blue perovskite; Step 7.2: Prepare a single charge transfer device and analyze the mobility of the vertically grown blue light quasi-two-dimensional perovskite film and the control film using the space charge limited current model; Step 7.3: Perform steady-state and transient luminescence spectra tests on the vertically grown blue quasi-two-dimensional perovskite film, and modify the wettability of the lower interface buffer layer of the quasi-two-dimensional blue perovskite to further adjust the grain boundary size of the quasi-two-dimensional blue perovskite and enhance the exciton radiative recombination of the quasi-two-dimensional blue perovskite; Step 7.4: By comparing the luminescence intensity, luminescence peak position, and luminescence lifetime characteristics, the exciton radiation and non-radiative recombination processes of the blue-light quasi-two-dimensional perovskite film are studied, and the exciton lifetime in the quasi-two-dimensional blue-light perovskite is analyzed; 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.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This application deeply analyzes the influence of different conditions on crystal growth during the crystallization process, obtains the optimal solution for the vertical growth of quasi-two-dimensional blue light perovskite crystals, constructs a crystal orientation perpendicular to the substrate, and thereby improves the charge transfer of quasi-two-dimensional blue light perovskite.

[0015] 2. This application analyzes the reasons why vertical growth improves the performance of blue light devices from the perspectives of defect states, energy levels, and charge transfer, studies the exciton radiation and non-radiative recombination processes of blue light quasi-two-dimensional perovskite films, analyzes the exciton lifetime in quasi-two-dimensional blue light perovskites, and 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 to enhance the exciton radiation recombination of the quasi-two-dimensional blue light perovskite, and selects different P-type semiconductor and N-type semiconductor materials as hole and electron transport layers according to material properties, respectively, to balance the hole-electron transport capacity of the device, broaden the light-emitting area, and prepare efficient and stable blue light PeLEDs devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of this application; Figure 2 This is the structure diagram of the quasi-two-dimensional blue PeLEDs device; Figure 3 This is a real picture of quasi-two-dimensional blue light PeLEDs emitting light under bias. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] Embodiment 1: A research method for preparing high-performance quasi-two-dimensional blue light PeLED devices, such as Figure 1 As shown, the following steps are included: Step 1: Establish a theoretical model for the vertical growth of perovskite, specifically: using the island growth model of polycrystalline thin film crystallization, the perovskite interface growth model and the carrier transport model, to establish a kinetic model for the vertical growth of inorganic crystals in quasi-two-dimensional blue light perovskite; Step 2: Through the established theoretical model, simulation is performed to obtain data on the effect of substrate temperature on the crystal orientation of blue light quasi-two-dimensional perovskite thin films in different film forming processes, which specifically includes the following steps: Step 2.1: According to the established kinetic model, the optical and electrical properties of the blue light quasi-two-dimensional perovskite film are obtained through simulation, and the optical simulation of the blue light PeLED is performed; Step 2.2: Based on the results obtained from optical simulation, further simulate the effect of substrate temperature on the crystal orientation of blue light quasi-two-dimensional perovskite film in different film forming processes; Step 3: preparing quasi-two-dimensional blue light perovskite solutions with different raw material ratios, specifically comprising the following steps: Step 3.1: PbBr2, MABr, CsBr, PEABr materials are selected as raw materials, and N, N-dimethylacetamide and dimethyl sulfoxide are selected as solvents; Step 3.2: dissolving the raw materials in two solvents or a mixed solvent 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; Step 4: Setting a gradient preheating temperature for the substrate to obtain crystallization conditions and crystal orientation data of the quasi-two-dimensional blue light perovskite solution at different substrate preheating temperatures, specifically comprising the following steps: Step 4.1: Set the preheating temperature of the substrate in a gradient from room temperature to 180°C, with each 5°C as a sample; Step 4.2: Using scanning electron microscopy and X-ray diffraction techniques to characterize the crystallization state and crystal orientation of quasi-two-dimensional blue light perovskite solutions with different raw material ratios at different preheating temperatures; Step 5: Gradient setting of the temperature of the antisolvent to obtain the crystal orientation data of the quasi-two-dimensional blue light perovskite solution under hot injection of antisolvents at different temperatures, specifically including the following steps: Step 5.1: Determine the boiling points of 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; Step 5.2: Using scanning electron microscopy and X-ray diffraction techniques to characterize the crystallization state and crystal orientation of quasi-two-dimensional blue light perovskite solutions with different raw material ratios at different preheating temperatures; Step 6: Using a PIN device structure with hole transport layers of different materials, obtain the orientation data of quasi-two-dimensional blue light perovskite crystals under hole transport layers of different materials, specifically including the following steps: Step 6.1: using oxides, small molecules, and polymers as hole transport layers respectively; Step 6.2: Analyze the effects of thin film wettability, functional groups, roughness, and microstructure of hole transport layers of different materials on crystal orientation, and determine the conditions for obtaining vertical growth; Step 7: Characterize the photoelectric properties of the crystallized quasi-two-dimensional blue light perovskite after regulation from step 3 to step 6 and the performance of the blue light perovskite light-emitting diode prepared therefrom, and analyze the reasons why vertical growth improves the performance of the blue light perovskite light-emitting diode from the perspectives of defect states, energy levels, and charge transfer, specifically including the following steps: Step 7.1: Using ion etching, study the electronic energy levels at different surface depths of the quasi-two-dimensional blue perovskite; Step 7.2: Prepare a single charge transfer device and analyze the mobility of the vertically grown blue light quasi-two-dimensional perovskite film and the control film using the space charge limited current model; Step 7.3: Perform steady-state and transient luminescence spectra tests on the vertically grown blue quasi-two-dimensional perovskite film, and modify the wettability of the lower interface buffer layer of the quasi-two-dimensional blue perovskite to further adjust the grain boundary size of the quasi-two-dimensional blue perovskite and enhance the exciton radiative recombination of the quasi-two-dimensional blue perovskite; Step 7.4: By comparing the luminescence intensity, luminescence peak position, and luminescence lifetime characteristics, the exciton radiation and non-radiative recombination processes of the blue-light quasi-two-dimensional perovskite film are studied, and the exciton lifetime in the quasi-two-dimensional blue-light perovskite is analyzed; Step 7.5: modifying the wettability of the lower interface buffer layer of the quasi-two-dimensional blue light perovskite, further adjusting the grain boundary size of the quasi-two-dimensional blue light perovskite, and enhancing the exciton radiative recombination of the quasi-two-dimensional blue light perovskite; Step 8: Adopting an adapted blue light device preparation process according to the characteristics of the quasi-two-dimensional blue light perovskite material, including screening different P-type semiconductor and N-type semiconductor materials as hole and electron transport layers respectively; Step 9: Finally, prepare a blue light device by combining the blue light quasi-two-dimensional perovskite 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.

[0021] In this embodiment, the present application deeply analyzes the influence of different conditions on crystal growth during the crystallization process, obtains the optimal solution for the vertical growth of quasi-two-dimensional blue light perovskite crystals, constructs a crystal orientation perpendicular to the substrate, and thereby improves the charge transfer of the quasi-two-dimensional blue light perovskite. The present application analyzes the reasons for the improvement of the performance of blue light devices by vertical growth from the perspectives of defect states, energy levels, and charge transfer, studies the exciton radiation and non-radiative recombination processes of blue light quasi-two-dimensional perovskite films, analyzes the exciton lifetime in the quasi-two-dimensional blue light perovskite, and 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, and selects different P-type semiconductors and N-type semiconductor materials according to the material properties as hole and electron transport layers, respectively, to balance the hole-electron transport capacity of the device, broaden the light-emitting area, and prepare efficient and stable blue light PeLEDs devices.

[0022] Figure 2 The structure diagram of the quasi-two-dimensional blue PeLEDs device developed Figure 3 This application provides a real photo of quasi-two-dimensional blue light PeLEDs emitting light under bias, including establishing a theoretical model, simulating the crystal orientation of blue light quasi-two-dimensional perovskite films, preparing quasi-two-dimensional blue light perovskite solutions, exploring the influence of different preheating temperatures, exploring the influence of hot injection of anti-solvents, using a PIN structure and using different hole transport layers to study the influence of the transport layer interface of perovskite growth on the crystal 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 diodes prepared therefrom.

[0023] The present invention innovatively adopts the island growth model of polycrystalline thin film crystallization, the perovskite interface growth model and the carrier transport model to establish a kinetic model for the vertical growth of inorganic crystals in quasi-two-dimensional blue perovskite; through interface regulation and process optimization, the vertically oriented crystal growth of quasi-two-dimensional blue perovskite is effectively regulated to promote the efficient transport of carriers at the interface of the functional layer and within the light-emitting layer; the preparation process of the vertical growth of quasi-two-dimensional blue perovskite is regulated to develop a high-performance blue PeLEDs device.

[0024] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them, and certainly not to limit the patent scope of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; 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 various embodiments of the present invention; that is, any changes or embellishments made to the main design concept and spirit of the present invention that have no substantive significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention; in addition, the direct or indirect application of the technical solutions of the present invention in other related technical fields are also included in the patent protection scope of the present invention.

Claims

1. A research method for preparing a high-performance quasi-two-dimensional blue light PeLED device, comprising the following steps: Step 1: Establish a theoretical model for vertical growth of perovskite; Step 2: Use the established theoretical model to simulate and obtain data on the effect of substrate temperature on the crystal orientation of blue light quasi-two-dimensional perovskite thin films in different film forming processes; Step 3: preparing quasi-two-dimensional blue light perovskite solutions with different raw material ratios; Step 4: setting a gradient preheating temperature for the substrate to obtain the crystallization state and crystal orientation data of the quasi-two-dimensional blue light perovskite solution at different substrate preheating temperatures; Step 5: Setting the temperature of the antisolvent in a gradient manner to obtain the crystal orientation data of the quasi-two-dimensional blue light perovskite solution under hot injection of antisolvents at different temperatures; Step 6: Using a PIN device structure with hole transport layers of different materials, obtain the orientation data of quasi-two-dimensional blue light perovskite crystals under hole transport layers of different materials; Step 7: Characterize the photoelectric properties of the crystallized quasi-two-dimensional blue light perovskite regulated by steps 3 to 6 and the performance of the blue light perovskite light-emitting diode prepared therefrom, and analyze the reasons why vertical growth improves the performance of the blue light perovskite light-emitting diode from the perspectives of defect states, energy levels, and charge transfer; Step 8: Adopting an adapted blue light device preparation process according to the characteristics of the quasi-two-dimensional blue light perovskite material, including screening different P-type semiconductor and N-type semiconductor materials as hole and electron transport layers respectively; Step 9: Finally, prepare a blue light device by combining the blue light quasi-two-dimensional perovskite 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.

2. The method for preparing a high-performance quasi-two-dimensional blue light PeLED device according to claim 1, characterized in that: Step 1 uses the island growth model of polycrystalline thin film crystallization, the perovskite interface growth model and the carrier transport model to establish a kinetic model for the vertical growth of inorganic crystals in quasi-two-dimensional blue light perovskite.

3. The method for preparing a high-performance quasi-two-dimensional blue light PeLED device according to claim 2, characterized in that: The specific steps of step 2 are as follows: Step 2.1: According to the established kinetic model, the optical and electrical properties of the blue light quasi-two-dimensional perovskite film are obtained through simulation, and the optical simulation of the blue light PeLED is performed; Step 2.2: Based on the results obtained from optical simulation, further simulate the effect of substrate temperature on the crystal orientation of blue light quasi-two-dimensional perovskite films in different film forming processes.

4. The method for preparing a high-performance quasi-two-dimensional blue light PeLED device according to claim 1, characterized in that: The specific steps of step 3 are as follows: Step 3.1: PbBr2, MABr, CsBr, PEABr materials are selected as raw materials, and N, N-dimethylacetamide and dimethyl sulfoxide are selected as solvents; Step 3.2: Dissolve the raw materials in two solvents or a mixed solvent of the two solvents in different ratios to prepare quasi-two-dimensional blue light perovskite solutions with a variety of different raw material ratios.

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

6. The method for preparing a high-performance quasi-two-dimensional blue light PeLED device according to claim 1, characterized in that: The specific steps of step 5 are as follows: Step 5.1: Determine the boiling points of 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; Step 5.2: Use scanning electron microscopy and X-ray diffraction technology to characterize the crystallization state and crystal orientation of quasi-two-dimensional blue light perovskite solutions with different raw material ratios at different preheating temperatures.

7. The method for preparing a high-performance quasi-two-dimensional blue light PeLED device according to claim 1, characterized in that: The specific steps of step 6 are as follows: Step 6.1: using oxides, small molecules, and polymers as hole transport layers respectively; Step 6.2: Analyze the effects of thin film wettability, functional groups, roughness, and microstructure of hole transport layers of different materials on crystal orientation to determine the conditions for obtaining vertical growth.

8. The method for preparing a high-performance quasi-two-dimensional blue light PeLED device according to claim 1, characterized in that: The specific steps of step 7 are as follows: Step 7.1: Using ion etching, study the electronic energy levels at different surface depths of the quasi-two-dimensional blue perovskite; Step 7.2: Prepare a single charge transfer device and analyze the mobility of the vertically grown blue light quasi-two-dimensional perovskite film and the control film using the space charge limited current model; Step 7.3: Perform steady-state and transient luminescence spectra tests on the vertically grown blue quasi-two-dimensional perovskite film, and modify the wettability of the lower interface buffer layer of the quasi-two-dimensional blue perovskite to further adjust the grain boundary size of the quasi-two-dimensional blue perovskite and enhance the exciton radiative recombination of the quasi-two-dimensional blue perovskite; Step 7.4: By comparing the luminescence intensity, luminescence peak position, and luminescence lifetime characteristics, the exciton radiation and non-radiative recombination processes of the blue-light quasi-two-dimensional perovskite film are studied, and the exciton lifetime in the quasi-two-dimensional blue-light perovskite is analyzed; 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.

Images