Preparation method of corner organic-inorganic heterojunction
Organic single crystals and single layer WS2 with different crystal orientations were prepared by micro-pitch growth method and mechanical peeling method, and the corner organic-inorganic heterojunction was constructed, which solved the problem of research on two-dimensional organic-inorganic heterostructures, and achieved efficient energy transfer and photoluminescence characteristics improvement.
Patent Information
- Application Number
- CN202510198223.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-22
- Publication Date
- 2025-05-23
AI Technical Summary
The research on two-dimensional organic-inorganic heterostructures in the prior art is relatively limited, mainly because the growth of high-quality organic single crystals with different orientations is difficult.
The micro-pitch growth method was used to grow organic single crystal 2,6-diphenyl anthracene (DPA) with different crystal orientations, and a single layer of transition metal chalcogen compound tungsten disulfide (WS2) was obtained by mechanical peeling method, and then an angle organic-inorganic heterojunction was constructed, and the rotation angle range was achieved by vertical stacking by dry transfer method to achieve a rotation angle range of 0-60°.
The rotation angle was successfully introduced into the two-dimensional organic-inorganic heterojunction, which improved the photoluminescence characteristics and anisotropy of the material, reduced the production cost, was easy to operate, and had high quality and different crystal orientations.
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Figure CN120035361A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of two-dimensional semiconductor materials, and in particular to a method for preparing a corner organic-inorganic heterojunction. Background Art
[0002] In recent years, two-dimensional materials have achieved amazing development and progress in the fields of electronics, optoelectronics, and integration. In particular, organic-inorganic heterostructures based on two-dimensional organic materials and two-dimensional inorganic materials have shown superior and promising properties in various aspects. Two-dimensional organic-inorganic heterostructures can successfully combine the advantages of the two materials and use complementary properties to form various optoelectronic devices. A new functional interface can also be formed between the two to enhance the interaction between light and matter. Angle rotation is an important means of regulating excitons in two-dimensional heterojunctions, and has unexpected effects on electronic and optical properties. The angle of adjacent layers can effectively regulate the interlayer distance, resulting in changes in the interlayer force, thereby changing the interlayer coupling strength. Angle rotation can lead to various interesting and unexpected phenomena, such as strong coupling at a specific angle, moiré fringes at a small twist angle, and semi-correlated insulating states in the twist angle. At the same time, the angle will also regulate the energy transfer efficiency, changing the formation and decay rate of excitons by changing the light absorption size and photoluminescence intensity of the constituent layers. Therefore, research on angle-rotated organic-inorganic heterojunctions has important application prospects.
[0003] At present, most of the research at home and abroad focuses on the angle control of pure inorganic two-dimensional materials, or on the research of organic-inorganic heterojunctions without angle control. The research on angled two-dimensional organic-inorganic heterostructures is still relatively limited, mainly because it is difficult to grow high-quality organic single crystals with different orientations. Summary of the invention
[0004] The purpose of the present invention is to provide a method for preparing an organic-inorganic heterojunction with a rotation angle. The preparation method is simple to operate, and the prepared heterostructure is of high quality, has no surface pollution, and has different rotation angles. The heterojunction has high anisotropy through energy transfer.
[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: a method for preparing an angled organic-inorganic heterojunction, using photoluminescence spectroscopy to verify the enhanced luminescence performance, and using angle-resolved photoluminescence spectroscopy to test that the heterostructure has high anisotropy to prove the energy transfer process. It includes the following steps:
[0006] 1) Growing organic single crystals of 2,6-diphenylanthracene (DPA) with different crystal orientations by micro-spacing growth method;
[0007] 2) Obtain a single layer of transition metal chalcogenide tungsten disulfide (WS) by mechanical exfoliation 2 );
[0008] 3) Construction of corner organic-inorganic heterojunction: Positioning operation under the transfer platform makes WS on the polydimethylsiloxane (PDMS) substrate 2 The monolayer was transferred onto a substrate grown with DPA of different crystal orientations, with the rotation angle ranging from 0 to 60°;
[0009] 4) Test heterojunction and single WS 2 The energy transfer process was determined by studying the polarization characteristics of the heterojunction using photoluminescence spectroscopy and angle-resolved photoluminescence spectroscopy.
[0010] Preferably, the specific steps of the micro-spacing growth method in step 1) are: dispersing powdered DPA on a lower substrate, placing sleepers on the lower substrate, placing an upper substrate on the sleepers, heating to allow the lower substrate powder to sublime and deposit on the upper substrate, and by adjusting the sleeper height, target growth temperature and growth time, obtaining organic single crystals with different crystal orientations on the upper substrate.
[0011] Preferably, the growth temperature of the organic single crystal in step 1) is 100-300°C, the growth time is 10-200min, and the sleeper height is 10-400μm. The thickness of the organic single crystal can be regulated by precise control of different conditions, and the thickness regulation range is 20-30nm.
[0012] Preferably, the specific steps of the mechanical stripping method in step 2) are: tape separation of block WS 2 to a thin layer and bonded to the PDMS substrate to make a single layer of WS 2 Stay on the PDMS substrate.
[0013] Preferably, the WS in step 2) 2 The single layer thickness is 0.6 nm.
[0014] Preferably, the corner organic-inorganic heterojunction in step 3) is formed by vertically stacking using a dry transfer method.
[0015] Preferably, the wavelength of the photoluminescence spectrum test laser in step 4) is set to 405 nm.
[0016] Compared with the prior art, the present invention has the following beneficial effects:
[0017] 1. The present invention provides a technology for preparing a corner organic-inorganic heterojunction, and the micro-spacing growth method used is more convenient to operate than the traditional method. Organic materials grown by traditional organic material synthesis methods usually have a large number of defects and doping, and are not suitable for optoelectronic micro-nano device applications. The thin layer of organic single crystals grown by the present invention is in a quadrilateral shape, and the crystal orientation of the organic single crystal can be directly determined according to the diagonal of the quadrilateral, which saves a lot of time and avoids the defect and pollution problems in the preparation of organic materials by conventional technology. The organic single crystals synthesized using this technology have high quality and different crystal orientations, low cost, simple operation, and a success rate of 90%.
[0018] 2. The present invention successfully introduces corners into a two-dimensional organic-inorganic heterojunction, adding a new degree of freedom.
[0019] 3. The corner organic-inorganic heterojunction prepared by the present invention can be used to prepare two-dimensional semiconductor electrical test devices, which can fully meet laboratory testing requirements, greatly improve electrical performance, and save a lot of experimental costs.
[0020] 4. The corner organic-inorganic heterojunction prepared by the present invention greatly improves the photoluminescence properties of the material through an efficient energy transfer process and has high anisotropy. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the process of preparing organic single crystals using the micro-spacing growth method of the present invention;
[0022] Figure 2 Schematic diagram of the corner organic-inorganic heterojunction structure of the present invention;
[0023] Figure 3 The organic single crystals with different crystal orientations grown in Example 1 and the prepared corner organic-inorganic heterojunctions;
[0024] Figure 4 The scanning electron microscope image and selected area electron diffraction image of the organic single crystal grown in Example 1;
[0025] Figure 5 The photoluminescence spectrum characteristics of the corner organic-inorganic heterojunction prepared in Example 1;
[0026] Figure 6 is the angle-dependent photoluminescence enhancement coefficient of the angled organic-inorganic heterojunction prepared in Example 1;
[0027] Figure 7 Polarization characteristics of the corner organic-inorganic heterojunction prepared in Example 1. DETAILED DESCRIPTION
[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] In the following examples, unless otherwise specified, the operating methods are generally carried out according to conventional operating methods or conditions recommended by manufacturers, and the raw materials and reagents used are all commercially available products.
[0030] Example 1
[0031] The present invention discloses a two-dimensional angle organic-inorganic heterojunction preparation technology, and verifies its enhanced luminescence performance through photoluminescence spectroscopy, tests the high anisotropy of the heterojunction through angle-resolved photoluminescence spectroscopy, and determines the energy transfer process. The specific process includes the following steps:
[0032] 1) Using the micro-spacing growth method to grow organic single crystal 2,6-diphenylanthracene (DPA) with different crystal orientations. Powdered organic source DPA is dispersed on the lower substrate, sleepers are placed on the lower substrate, the height of the sleepers is 10-400 μm, and the upper substrate (organic single crystal deposition substrate) is placed on the sleepers. The heating stage is used to heat the DPA powder on the lower substrate at a temperature of 100-300°C for 10-200 minutes to sublimate the DPA powder on the lower substrate to deposit on the upper substrate, and the organic single crystal DPA with different crystal orientations is synthesized. The growth process is as follows: Figure 1 As shown, the optical microscope image of the grown DPA is shown in Figure 3 a. In selected area electron diffraction, by focusing the electron beam on a small area of the sample and collecting the diffraction pattern, the crystalline structure and single crystal properties of this area can be further confirmed. Figure 4 In the experiment, the grown 2D DPA showed the same diffraction pattern at multiple different positions, which confirmed that the grown DPA was a single crystal with high quality;
[0033] The lower substrate and the upper substrate described in the present application can be made of conventional substrate materials in the art, such as silicon / silicon dioxide substrate, quartz substrate, ITO glass substrate, etc. In this embodiment, a silicon / silicon dioxide substrate is selected;
[0034] The present application can achieve regulation of the thickness of the organic single crystal DPA by precise control of different conditions (such as sleeper height, target growth temperature and growth time, etc.), and the thickness regulation range is 20-30nm.
[0035] 2) Obtaining a single layer of WS by mechanical exfoliation 2 . The tape is torn apart to separate the block WS 2 to a thin layer and bonded to the PDMS substrate to make a single layer of WS 2 Remaining on the PDMS substrate, the WS can be determined by optical microscopy using interference phenomena 2 The number of layers can also be observed by fluorescence microscopy. 2 The fluorescence intensity determines the number of layers. In this example, WS 2The single layer thickness is 0.6 nm.
[0036] 3) Single-layer WS 2 The dry transfer method is used to vertically stack onto high-quality organic single crystal DPA with different crystal orientations, and the positioning operation is performed under the transfer platform to construct an angled organic-inorganic heterojunction with an angle range of 0-60°. Figure 2 As shown; the obtained optical microscope image of the corner organic-inorganic heterojunction is shown Figure 3 As shown in b.
[0037] 4) Set the laser wavelength to 405nm and test the heterojunction and single WS 2 The photoluminescence spectrum of Figure 5 As shown, the photoluminescence intensity of the heterojunction is compared with that of the single WS 2 The energy transfer process is the transfer of electron-hole pairs from the DPA layer to the WS 2 layer to enhance the optical performance.
[0038] The laser wavelength was set to 405 nm, the photoluminescence spectra of the heterojunction at different rotation angles were tested, and the enhancement coefficient was calculated. The results are as follows: Figure 6 As shown in the figure, the photoluminescence enhancement coefficient changes nonlinearly with the rotation angle. This is because different rotation angles can regulate energy transfer by affecting the interlayer distance, and have strong coupling strength at specific rotation angles. For example, in the 2,6-diphenylanthracene / tungsten disulfide heterojunction of this embodiment, the photoluminescence enhancement coefficient can reach ~7.9 at a rotation angle of ~21.6°.
[0039] Set the laser wavelength to 405nm to test the heterojunction and single WS 2 The angle-resolved photoluminescence spectrum is plotted as Figure 7 As shown, the heterojunction has high anisotropy, while the single WS 2 Isotropic, determining the energy transfer process.
Claims
1. A method for preparing a corner organic-inorganic heterojunction, characterized in that: The following steps are involved: 1) Growing organic single crystal 2,6-diphenylanthracene with different crystal orientations by micro-spacing growth method; 2) Obtaining a monolayer of transition metal chalcogenide tungsten disulfide by mechanical exfoliation; 3) Construction of an angled organic-inorganic heterojunction: Positioning operation under the transfer platform allows the tungsten disulfide monolayer on the polydimethylsiloxane substrate to be transferred to a substrate on which an organic single crystal 2,6-diphenylanthracene with a different crystal orientation is grown, with an angle range of 0-60°; 4) Test the photoluminescence spectra and angle-resolved photoluminescence spectra of the heterojunction and tungsten disulfide alone, and determine the energy transfer process by studying the polarization characteristics of the heterojunction.
2. The method for preparing a corner organic-inorganic heterojunction according to claim 1, characterized in that: The specific steps of the micro-spacing growth method described in step 1) are: dispersing powdered 2,6-diphenylanthracene on a lower substrate, placing sleepers on the lower substrate, placing an upper substrate on the sleepers, heating to allow the lower substrate powder to sublime and deposit on the upper substrate, and by adjusting the sleeper height, target growth temperature and growth time, an organic single crystal with different crystal orientations is obtained on the upper substrate.
3. The method for preparing a corner organic-inorganic heterojunction according to claim 2, characterized in that: The growth temperature of the organic single crystal in step 1) is 100-300° C., the growth time is 10-200 min, and the sleeper height is 10-400 μm.
4. The method for preparing a corner organic-inorganic heterojunction according to claim 1, characterized in that: The specific steps of the mechanical stripping method in step 2) are: using an adhesive tape to separate the bulk tungsten disulfide into a thin layer, and attaching it to a polydimethylsiloxane substrate, so that a single layer of tungsten disulfide remains on the polydimethylsiloxane substrate.
5. The method for preparing a corner organic-inorganic heterojunction according to claim 1, characterized in that: The thickness of the tungsten disulfide single layer in step 2) is 0.6 nm.
6. The method for preparing a corner organic-inorganic heterojunction according to claim 1, characterized in that: The corner organic-inorganic heterojunction in step 3) is formed by vertical stacking using a dry transfer method.
7. The method for preparing a corner organic-inorganic heterojunction according to claim 1, characterized in that: The wavelength of the photoluminescence spectrum test laser in step 4) is set to 405 nm.