A hexagonal Cu3GeS4 quantum dot, its preparation method and application
By synthesizing hexagonal Cu3GeS4 quantum dots with controllable size and uniform morphology under mild reaction conditions and controlled heating procedures, the problems of high energy consumption and non-uniform morphology in the prior art are solved, thus improving the performance of photodetectors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QUFU NORMAL UNIV
- Filing Date
- 2025-07-25
- Publication Date
- 2026-06-16
Smart Images
Figure CN120864552B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of novel multi-component photoelectric conversion materials, specifically relating to a hexagonal Cu3GeS4 quantum dot, the preparation method of the quantum dot material, and its application in the field of photoelectric conversion. Background Technology
[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
[0003] Copper-based chalcogenides, due to their tunable atomic ratios, diverse crystal structures, high light absorption coefficients, and high carrier mobility, have become ideal materials to replace cadmium-based or lead-based compounds, and have been widely studied and applied in energy, environment, and biomedicine research fields.
[0004] In recent years, copper-germanium-sulfur nanomaterials have attracted close attention from researchers as multifunctional materials widely used in research fields such as solar cells, catalysis, thermoelectric conversion, and tumor diagnosis and treatment. However, there are currently very few reports on Cu3GeS4 nanomaterials among the copper-germanium-sulfur nanomaterials studied.
[0005] It is well known that the reactivity of reactants and the thermodynamic and kinetic factors of the reaction process have a significant impact on the elemental composition and crystal structure of the reaction products. Studies have found that Cu3GeS4 can be obtained by heating pure elements in stoichiometric proportions to ~1000℃ in a vacuum quartz tube via a high-temperature solid-state method, followed by slow cooling. However, the high-temperature solid-state reaction method for synthesizing Cu3GeS4 not only requires high energy consumption and a long time, but the products often exhibit uncontrollable size and non-uniform morphology, thus affecting or limiting the performance of Cu3GeS4 and its application in micro / nano device fabrication. Summary of the Invention
[0006] To address the aforementioned problems, this invention provides a hexagonal Cu3GeS4 quantum dot, its preparation method, and its applications. The method of this invention features mild reaction conditions and a simple process, achieving controllable preparation of hexagonal Cu3GeS4 quantum dots with controllable size, uniform morphology, and monodispersity. To achieve the above objectives, this invention discloses the following technical solution:
[0007] In a first aspect, the present invention provides a hexagonal Cu3GeS4 quantum dot, wherein the quantum dot material has a hexagonal crystal structure and its XRD diffraction is at 2... θIt has characteristic peaks at 27.8±0.2°, 28.9±0.2°, 31.5±0.2°, 40.6±0.2°, 49.3±0.2°, 52.9±0.2°, and 58.3±0.2°; its microstructure is spherical or polyhedral, and the particle size is 3~10nm.
[0008] The hexagonal Cu3GeS4 synthesized in this invention is monodisperse. Transmission electron microscopy reveals that the nanomaterials are nanoscale spherical and near-spherical polyhedra, exhibiting a high degree of uniformity in size and morphology. As a photoresponsive material, the size uniformity of these monodisperse quantum dots or nanoparticles facilitates precise control of light absorption / emission wavelengths. Compared to polydisperse materials in existing technologies, the nanomaterials provided by this invention can effectively reduce ineffective energy loss and improve light capture efficiency.
[0009] In a second aspect, the present invention provides a method for preparing hexagonal Cu3GeS4 quantum dots as described in the first aspect, comprising the following steps:
[0010] (1) Add germanium dioxide to a medium of mercaptoacetic acid and ammonia to dissolve it to obtain a germanium solution;
[0011] (2) Dissolve the copper source in a high-boiling-point organic solvent and heat it to the first temperature and react at a constant temperature for a period of time. Then, rapidly raise the temperature to the second temperature and inject the germanium solution prepared in step (1). After the reaction is completed, separate the solid product to obtain the product.
[0012] Furthermore, the above preparation method also has the following preferred embodiments:
[0013] In step (1), the molar ratio of germanium dioxide: mercaptoacetic acid: ammonia is 1:4~36:1~2, and the temperature of the dissolution process is controlled at 20~30℃. It can be dissolved by ultrasound or stirring.
[0014] In step (2) above:
[0015] The copper source is a copper salt capable of ionizing copper ions, including organic and inorganic salts, such as copper acetylacetonate, cuprous chloride, cuprous chloride, cuprous bromide, or copper acetate.
[0016] The high-boiling-point reaction medium is selected from any one or a combination of several of oleylamine, octadecylamine, hexadecylamine, oleic acid, and octadecene.
[0017] The dosage ratio of the copper source, germanium solution, and high-boiling-point organic solvent is 0.6 mmol: 220~660 μL: 8~10 mL, and the solution is deoxygenated and dehydrated.
[0018] The heating described in step (2) above includes a first stage and a second stage; dissolving the copper source in a high-boiling-point organic solvent and heating it is considered the first stage. The purpose of heating in this stage is mainly to remove dissolved oxygen and moisture in the reaction system by raising the temperature. Therefore, the more suitable temperature range for the first temperature is 110~130℃, and the heating time is 30~60min.
[0019] The second stage involves rapid heating and injection of a germanium solution. A reasonable heating rate is 25–35 °C / min, and more ideally 27–32 °C / min. The second temperature is 190–280 °C, and the heating time is 5–90 min. After the reaction is complete, the solid product can be retained by centrifugation or filtration and then washed with reagents such as hexane and / or ethanol.
[0020] In a third aspect, the present invention provides the application of the hexagonal Cu3GeS4 quantum dots described in the first aspect in the field of photoelectric conversion.
[0021] As verified by this invention, the hexagonal Cu3GeS4 quantum dots exhibit high absorption capacity across a broad ultraviolet-visible-near-infrared spectral range. When used as the absorption layer of a photodetector, they can generate stable electrical signal responses under irradiation at different wavelengths of light. Therefore, feasible applications of the aforementioned nanomaterials include, but are not limited to:
[0022] (1) Used to prepare photodetectors;
[0023] (2) Used in the fabrication of photovoltaic devices, such as solar panels;
[0024] (3) Used to prepare optoelectronic integrated systems, such as photonic chips.
[0025] In the above-mentioned methods, one feasible way to apply the hexagonal Cu3GeS4 quantum dots is to disperse the hexagonal Cu3GeS4 quantum dots in an organic solvent and coat them onto a device substrate to form a film.
[0026] Compared with the prior art, the beneficial effects of the present invention are:
[0027] The hexagonal Cu3GeS4 quantum dots synthesized by the method of this invention have uniform morphology and size, and good monodispersity, making them easy to fabricate into micro- and nano-films on device substrates via spin coating or drop coating. Furthermore, this structure of Cu3GeS4 exhibits high absorption capacity over a wide spectral range, thus enabling photodetectors constructed from Cu3GeS4 quantum dots to possess advantages such as fast response speed and high stability. Attached Figure Description
[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0029] Figure 1 It is the X-ray diffraction pattern (XRD) of the target product in the first embodiment.
[0030] Figure 2 This is a transmission electron microscope (TEM) image of the target product of the first embodiment.
[0031] Figure 3 This is the ultraviolet-visible-near-infrared absorption (UV-vis-NIR) spectrum of the target product in the first embodiment.
[0032] Figure 4 The image shows the It curve of the photodetector constructed from the target product of the first embodiment under 405nm wavelength light irradiation.
[0033] Figure 5 The image shows the It curve of the photodetector constructed from the target product of the first embodiment under 650nm wavelength light irradiation.
[0034] Figure 6 The curve shown is the It curve of the photodetector constructed from the target product of the first embodiment under 1310nm wavelength light irradiation.
[0035] Figure 7 This is the X-ray diffraction pattern (XRD) of the target product in the second embodiment.
[0036] Figure 8 This is a transmission electron microscope (TEM) image of the target product of the third embodiment.
[0037] Figure 9 This is the X-ray diffraction pattern (XRD) of the target product in the fourth embodiment.
[0038] Figure 10 This is a transmission electron microscope (TEM) image of the target product of the fifth embodiment. Detailed Implementation
[0039] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.
[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods or product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described herein are for illustrative purposes only. The invention will now be further described with reference to the accompanying drawings and specific embodiments.
[0041] First Embodiment
[0042] In this embodiment, a hexagonal Cu3GeS4 quantum dot and its preparation method are provided, including the following steps:
[0043] (1) Add 2 mmol of germanium dioxide, 1.1 mL of mercaptoacetic acid and 1.1 mL of ammonia to a 10 mL sample bottle, sonicate and keep the solution temperature at 25 °C to completely dissolve germanium dioxide to obtain germanium solution.
[0044] (2) Add 0.6 mmol of cuprous chloride and 8 mL of oleylamine to a 100 mL three-necked flask. Purge with nitrogen and heat the mixture to 130 °C under magnetic stirring for 30 min. Then, rapidly heat to 280 °C at 30 °C / min. At this point, inject 220 μL of the germanium solution prepared in (1) and 1.0 mL of oleylamine and keep the mixture at this temperature for 5 min. After the reaction is complete, cool to room temperature, centrifuge to separate the solid product from the reaction solution, and then wash the solid product three times with cyclohexane and anhydrous ethanol. The obtained solid product is the target product.
[0045] Second Embodiment
[0046] In this embodiment, another hexagonal Cu3GeS4 quantum dot and its preparation method are provided, including the following steps:
[0047] (1) Add 2 mmol of germanium dioxide, 1.1 mL of mercaptoacetic acid and 1.1 mL of ammonia to a 10 mL sample bottle, sonicate and keep the solution temperature at 25 °C to completely dissolve germanium dioxide to obtain germanium solution.
[0048] (2) Add 0.6 mmol of cuprous bromide and 8 mL of oleylamine to a 100 mL three-necked flask. Purge with nitrogen and heat the mixture to 110 °C under magnetic stirring for 60 min. Then, rapidly heat to 260 °C at 30 °C / min. At this point, inject 220 μL of the germanium solution prepared in (1) and 1.0 mL of oleylamine and keep the mixture at this temperature for 30 min. After the reaction is complete, cool to room temperature, centrifuge to separate the solid product from the reaction solution, and then wash the solid product three times with cyclohexane and anhydrous ethanol. The obtained solid product is the target product.
[0049] Third Embodiment
[0050] In this embodiment, another hexagonal Cu3GeS4 quantum dot and its preparation method are provided, including the following steps:
[0051] (1) Add 2 mmol of germanium dioxide, 2.2 mL of mercaptoacetic acid and 1.1 mL of ammonia to a 10 mL sample bottle, sonicate and keep the solution temperature at 25 °C to completely dissolve germanium dioxide to obtain germanium solution.
[0052] (2) Add 0.6 mmol of copper chloride and 8 mL of oleylamine to a 100 mL three-necked flask. Purge with nitrogen and heat the mixture to 120 °C under magnetic stirring for 30 min. Then, rapidly heat to 240 °C at 30 °C / min. At this point, inject 330 μL of the germanium solution prepared in (1) and 0.5 mL of oleylamine and keep the mixture at this temperature for 60 min. After the reaction is complete, cool to room temperature, centrifuge to separate the solid product from the reaction solution, and then wash the solid product three times with cyclohexane and anhydrous ethanol. The obtained solid product is the target product.
[0053] Fourth embodiment
[0054] In this embodiment, another type of hexagonal Cu3GeS4 quantum dot and its preparation method are provided, including the following steps:
[0055] (1) Add 2 mmol of germanium dioxide, 1.1 mL of mercaptoacetic acid and 1.1 mL of ammonia to a 10 mL sample bottle, sonicate and keep the solution temperature at 20 °C to completely dissolve germanium dioxide to obtain germanium solution.
[0056] (2) Add 0.6 mmol of acetylacetone and 8 mL of oleylamine to a 100 mL three-necked flask. Purge with nitrogen and heat the mixture to 120 °C under magnetic stirring for 60 min. Then, rapidly heat to 190 °C at 30 °C / min, and inject 220 μL of the germanium solution prepared in (1) and 1.0 mL of oleylamine and keep the mixture at this temperature for 90 min. After the reaction is complete, cool to room temperature, centrifuge to separate the solid product from the reaction solution, and then wash the solid product three times with cyclohexane and anhydrous ethanol. The obtained solid product is the target product.
[0057] Fifth embodiment
[0058] In this embodiment, another hexagonal Cu3GeS4 quantum dot and its preparation method are provided, including the following steps:
[0059] (1) Add 2 mmol of germanium dioxide, 4.4 mL of mercaptoacetic acid and 2.2 mL of ammonia water to a 10 mL sample bottle, sonicate and keep the solution temperature at 30 °C to completely dissolve the germanium dioxide to obtain a germanium solution.
[0060] (2) Add 0.6 mmol of cuprous chloride and 8 mL of oleylamine to a 100 mL three-necked flask. Purge with nitrogen and heat the mixture to 120 °C under magnetic stirring for 60 min. Then, rapidly heat to 210 °C at 30 °C / min, and inject 660 μL of the germanium solution prepared in (1) and 0.5 mL of oleylamine and keep the mixture at this temperature for 60 min. After the reaction is complete, cool to room temperature, centrifuge to separate the solid product from the reaction solution, and then wash the solid product three times with cyclohexane and anhydrous ethanol. The obtained solid product is the target product.
[0061] Composition, structure characterization and performance testing
[0062] Figure 1 The image shows the X-ray diffraction pattern of the target product obtained in the first embodiment. As can be seen from the figure, all diffraction peaks accurately represent the corresponding crystal planes in Cu3GeS4 (JCPDS Card No. 41-1031), and no other impurity peaks appear, indicating that the target product prepared by the method of this embodiment is a hexagonal Cu3GeS4 crystal. Similarly, Figure 7 , Figure 9 The results also showed that the target products prepared in the second and fourth embodiments had the same properties as... Figure 1 Similar results.
[0063] Figure 2The transmission electron microscope (TEM) image of the target product obtained in the first embodiment shows that the Cu3GeS4 prepared by this method is a spherical nanomaterial with an average diameter of approximately 9.0 nm, and the size of the obtained Cu3GeS4 is uniform and controllable. Similarly, Figure 8 , Figure 10 The results also showed that the target products prepared in the third and fifth embodiments were monodisperse and had uniform and controllable size.
[0064] Figure 3 The UV-Vis-NIR light absorption spectrum of the product obtained in the first embodiment shows that the hexagonal Cu3GeS4 nanomaterial has strong absorption in the visible light range, indicating that the Cu3GeS4 nanomaterial prepared by this method can be used as a broadband photoelectric conversion material.
[0065] Figure 4 , Figure 5 and Figure 6 The It curve is shown for the photodetector constructed using the product obtained in the first embodiment. First, the target product obtained in the first embodiment was ultrasonically dispersed in cyclohexane to prepare a viscous solution, which was then spin-coated onto glass, and a Cu3GeS4 photodetector was constructed using ITO as the electrode. Figure 4 , Figure 5 and Figure 6 As shown, it can be seen that at 405nm ( Figure 4 ), 650nm ( Figure 5 ) and 1310nm ( Figure 6 Under conditions of wavelength light irradiation and an applied bias voltage of 0.5V, the photodetector exhibits good responsiveness and stability.
[0066] Figure 10 The image shown is a transmission electron microscope (TEM) image of the target product obtained in the fifth embodiment, which shows that the Cu3GeS4 quantum dots prepared by this method have a diameter of approximately 3 nm, and the size is uniform and controllable, and they have good crystallinity.
[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A hexagonal Cu3GeS4 quantum dot, characterized in that, The XRD diffraction of the quantum dots in 2 θ It has characteristic peaks at 27.8±0.2°, 28.9±0.2°, 31.5±0.2°, 40.6±0.2°, 49.3±0.2°, 52.9±0.2°, and 58.3±0.2°; its microstructure is spherical or polyhedral, and the particle size is 3~10nm.
2. The method for preparing hexagonal Cu3GeS4 quantum dots according to claim 1, characterized in that, Includes the following steps: (1) Add germanium dioxide to mercaptoacetic acid and ammonia water to dissolve and obtain germanium solution; the molar ratio of germanium dioxide: mercaptoacetic acid: ammonia water is 1:4~36:1~2, and the temperature of the dissolution process is controlled at 20~30℃; (2) Dissolve the copper source in a high-boiling-point organic solvent and heat it to the first temperature and react at a constant temperature for a period of time. Then, rapidly raise the temperature to the second temperature and inject the germanium solution prepared in step (1). After the reaction is completed, separate the solid product to obtain the product. The copper source is selected from any one or a combination of several of copper acetylacetonate, cuprous chloride, cupric chloride, cuprous bromide, or copper acetate; The high-boiling-point organic solvent is selected from any one or a combination of several of oleylamine, octadecylamine, hexadecylamine, oleic acid, and octadecene.
3. The method for preparing hexagonal Cu3GeS4 quantum dots as described in claim 2, characterized in that, The dosage ratio of the copper source, germanium solution, and high-boiling-point organic solvent is 0.6 mmol: 220~660 μL: 8~10 mL.
4. The method for preparing hexagonal Cu3GeS4 quantum dots as described in claim 2, characterized in that, In step (2), the first temperature is 110~130℃ and the heating time is 30~60min; the second stage is rapid heating and injection of germanium solution, and the rapid heating rate is 25~35℃ / min.
5. The method for preparing hexagonal Cu3GeS4 quantum dots as described in claim 4, characterized in that, The heating rate is 27~32℃ / min, the second temperature is 190~280℃, and the heating time is 5~90min.
6. The application of the hexagonal Cu3GeS4 quantum dots as described in claim 1 in the field of photoelectric conversion.
7. The application as described in claim 6, characterized in that, The application method is any one of the following: (1) Used to prepare photodetectors; (2) Used in the fabrication of photovoltaic devices; (3) Used to prepare optoelectronic integrated systems.
8. The application as described in claim 7, characterized in that, The photovoltaic device is a solar panel, and the optoelectronic integrated system is a photonic chip.
9. The application as described in claim 7 or 8, characterized in that, In any of the following applications (1)-(3), the hexagonal Cu3GeS4 quantum dots are dispersed in an organic solvent and coated onto a device substrate to form a film.