Environment-friendly copper-gallium-chalcogenide zinc sulfide core-shell quantum dots, preparation method and application thereof

Abstract

The application discloses an environment-friendly copper-gallium-chalcogenide zinc sulfide core-shell quantum dot as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing a gallium source, a copper source, oleylamine and 1-dodecyl mercaptan, heating, degassing in a nitrogen environment, adding a sulfur precursor solution, reacting, obtaining a quantum dot solution, heating the quantum dot solution, adding a zinc acetate precursor solution dropwise and stirring to react, continuously heating, adding a zinc stearate precursor solution dropwise and stirring to react, water quenching after the reaction, purifying, and obtaining a copper-gallium-chalcogenide zinc sulfide core-shell quantum dot. The copper-gallium-chalcogenide zinc sulfide core-shell quantum dot material prepared by the method of the application does not add toxic heavy metal materials, is harmless to human bodies and the environment, and has the advantage of high light condensation efficiency, and can effectively solve the problems of existing quantum dot materials.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of quantum dot materials, and particularly relates to an environmentally friendly copper-gallium-chalcogen sulfide zinc core-shell quantum dot as well as a preparation method and application thereof. BACKGROUND

[0002] A fluorescent solar concentrator is a kind of optoelectronic device that can act as a solar collector for photovoltaic cells. When exposed to sunlight, the fluorescent material embedded in the waveguide or the top surface of the waveguide can absorb solar radiation and re-emit photons of longer wavelengths, which are transmitted to the photovoltaic cells installed at the edge of the concentrator through total internal reflection, converting concentrated sunlight into electrical energy. Compared with traditional concentrators, fluorescent solar concentrators can absorb sunlight without angle dependence, which means that there is no need to install a complex solar tracking system, and there is no potential harm to the material itself and the surrounding environment due to the temperature rise after concentration. The design of the structure of the fluorescent solar concentrator is an effective means to improve its efficiency, and the structure of the series fluorescent solar concentrator can achieve higher device performance than a single fluorescent solar concentrator.

[0003] Quantum dot materials are often used as luminescent materials in fluorescent solar concentrators due to their unique size / composition dependence and excellent optical properties, including tunable Stokes shift and high photoluminescence quantum yield. However, there are still some challenges in current quantum dot-based fluorescent solar concentrators, such as reabsorption due to wide spectral overlap between absorption / emission spectra and adverse effects of surface defects / traps on photoluminescence quantum yield. By adjusting the composition and constructing heterostructure core / shell structures, the absorption and emission spectra can be adjusted to obtain a larger Stokes shift, and the shell structure can also provide efficient surface passivation to reduce surface traps / defects. During the shell coating process, the passivation effect produced by using different active precursors also varies. In addition, the quantum dots assembled in most high-performance fluorescent solar concentrators are II-VI / IV-VI group semiconductors composed of highly toxic heavy metals (Cd, Pb, Hg), which can easily harm the environment and human health, and also hinder the commercialization of this technology.

[0004] In recent years, environmentally friendly I-III-VI group core / shell quantum dots have been widely studied, and copper-gallium-chalcogen sulfide zinc core / shell quantum dots can be used as luminescent materials in solar fluorescent concentrators due to their small reabsorption and high photoluminescence quantum yield. However, there is still a lot of room for improvement in the optical performance of the prepared quantum dots and the device performance of the solar fluorescent concentrator based on copper-gallium-chalcogen core / shell quantum dots. SUMMARY

[0005] To address the aforementioned shortcomings in existing technologies, this invention provides an environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dot, its preparation method, and its applications. The copper gallium chalcogenide zinc sulfide core-shell quantum dot material prepared using the method of this invention does not contain any highly toxic heavy metal materials, posing no harm to the human body or the environment. Furthermore, the copper gallium chalcogenide zinc sulfide core-shell quantum dot material prepared in this invention has the advantage of high light-gathering efficiency, effectively solving the problems existing in current quantum dot materials.

[0006] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is as follows:

[0007] A method for preparing environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots includes the following steps:

[0008] (1) Mix gallium source, copper source, oleylamine and 1-dodecyl mercaptan, heat the mixture to 115-130°C in a nitrogen environment, then degas it in a nitrogen environment, then continue to heat it to 175-190°C, and add sulfur precursor solution to it to react and obtain quantum dot solution.

[0009] (2) Heat the quantum dot solution in step (1) to 210-220℃, add zinc acetate precursor solution dropwise and stir to react, then continue to heat to 250-260℃, add zinc stearate precursor solution dropwise and stir to react, after the reaction is completed, quench in water bath and purify to obtain copper gallium sulfide / zinc sulfide core-shell quantum dots.

[0010] Further, in step (1), the molar volume ratio of gallium source, copper source, oleylamine, 1-dodecylthiol and sulfur precursor solution is 0.4-0.6 mmol: 0.1-0.15 mmol: 2-3 ml: 0.2-0.3 ml: 1.5-2.5 ml.

[0011] Furthermore, step (1) also contains an indium source, a gallium source, a copper source, an indium source, an oleylamine, a 1-dodecyl mercaptan and a sulfur precursor solution with a molar volume ratio of 0.1-0.15 mmol:0.04-0.08 mmol:0-0.15 mmol:2-3 ml:0.2-0.3 ml:1.5-2.5 ml, to prepare copper gallium indium sulfide / zinc sulfide core-shell quantum dots.

[0012] Furthermore, in step (1), the gallium source is gallium acetylacetonate, the copper source is cuprous iodide, and the indium source is indium acetate.

[0013] Further, the sulfur precursor solution in step (1) is prepared by mixing sulfur powder and octadecene in a molar volume ratio of 1-2 mmol: 1-2 ml.

[0014] Further, the volume ratio of the quantum dot solution, the zinc acetate precursor solution and the zinc stearate precursor solution in step (2) is 4-6 ml:5-7 ml:3-5 ml.

[0015] Further, the zinc acetate precursor solution in step (2) is prepared by mixing anhydrous zinc acetate, oleic acid, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 3-5 mmol:3-5 ml:1-3 ml:5-7 ml.

[0016] The zinc stearate precursor solution in step (2) is prepared by mixing zinc stearate, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 3-5 mmol:1-3 ml:5-7 ml.

[0017] Further, the dropping speed of the zinc acetate precursor solution and the zinc stearate precursor solution in step (2) is 0.8-1.2 ml / min.

[0018] Further, the purification process in step (2) is as follows: after mixing the copper-gallium-chalcogenide zinc sulfide core-shell quantum dots and toluene in a volume ratio of 1:3, centrifugation is performed at a speed of 3000 r / min, the supernatant is taken, the supernatant and ethanol are mixed in a volume ratio of 1:2, centrifugation is performed at a speed of 12000 r / min, the precipitate is collected, and drying is performed to obtain the product.

[0019] An environment-friendly copper-gallium-chalcogenide zinc sulfide core-shell quantum dot includes copper-gallium-sulfur / zinc sulfide core-shell quantum dots and / or copper-gallium-indium-sulfur / zinc sulfide core-shell quantum dots, and is prepared by the above method.

[0020] The above environment-friendly copper-gallium-chalcogenide zinc sulfide core-shell quantum dot is applied to the preparation of a fluorescent solar concentrator.

[0021] Further, the copper-gallium-sulfur / zinc sulfide core-shell quantum dots are used as the top layer of the fluorescent solar concentrator, the copper-gallium-indium-sulfur / zinc sulfide core-shell quantum dots are used as the bottom layer of the fluorescent solar concentrator, and a polymer separation layer is arranged between the two layers.

[0022] The present application has the following beneficial effects:

[0023] 1. In the preparation of the copper-gallium-chalcogenide zinc sulfide core-shell quantum dot, the surface defects of the copper-gallium-chalcogenide core are passivated by the zinc sulfide shell layer, which greatly improves the stability of the quantum dot, effectively suppresses non-radiative recombination, and improves the yield of photoluminescence quantum dots.

[0024] 2、The introduction of indium source in the application makes the band gap decrease, which is suitable for absorbing the long wave part in the solar spectrum, so as to realize the structural design of the series fluorescent solar concentrator. Specifically, the fluorescent solar concentrator based on copper-gallium-sulfur / zinc sulfide core-shell quantum dots exhibits an optical efficiency of 2.91%, the fluorescent solar concentrator based on copper-gallium-indium-sulfur / zinc sulfide core-shell quantum dots exhibits an optical efficiency of 6.20%, and the series fluorescent solar concentrator exhibits an optical efficiency of up to 8.50%. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Transmission electron microscope image of quantum dots in Example 1;

[0026] Figure 2 Transmission electron microscope image of quantum dots in Example 4;

[0027] Figure 3 Actual photos of different fluorescent solar concentrators;

[0028] Figure 4 Performance detection diagram of different fluorescent solar concentrators-standard solar cells. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application, that is, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments.

[0030] Therefore, the detailed description of the embodiments of the present application provided below is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application.

[0031] It should be noted that the relational terms such as "first" and "second" and the like are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or equipment including the element.

[0032] The features and properties of the present application will be further described in detail below with reference to the embodiments and accompanying drawings.

[0033] Example 1

[0034] An environment-friendly copper-gallium-sulfur family zinc sulfide core-shell quantum dot, a preparation method thereof comprises the following steps:

[0035] (1) Put 0.5 mmol of gallium acetylacetone, 0.125 mmol of cuprous iodide, 2.5 ml of oleylamine and 0.25 ml of 1-dodecyl mercaptan into a 50 ml three-necked flask, heat using a heating jacket with a magnetic stirrer, and under nitrogen purging, warm up to 120℃, then degas for 60 min in a nitrogen gas environment, then continue to warm up to 180℃, and add 2 ml of a sulfur precursor solution thereto, react for 5 min to form a CGS core quantum dot solution;

[0036] The sulfur precursor solution is prepared by the following method: mix sulfur powder and octadecene according to a molar volume ratio of 4 mmol:4 ml, and ultrasonically treat for 30 min at a frequency of 4000 Hz to prepare the CGS core quantum dot solution;

[0037] (2) Warm up 5 ml of the CGS core quantum dot solution in step (1) to 210℃, and drop 6 ml of a zinc acetate precursor solution thereinto at a speed of 1 ml / min and stir for 30 min, then continue to warm up to 250℃, and drop 4 ml of a zinc stearate precursor solution thereinto at a speed of 1 ml / min and stir for 1 h, after the reaction is completed, quench with a water bath, mix the mixed solution with toluene according to a volume ratio of 1:3, then centrifuge at a speed of 3000 r / min, take the supernatant, mix the supernatant with ethanol according to a volume ratio of 1:2, centrifuge at a speed of 12000 r / min, collect the precipitate, and air dry to prepare CuGaS2 / ZnS core-shell quantum dots;

[0038] The zinc acetate precursor solution is prepared by the following method: mix anhydrous zinc acetate, oleic acid, 1-dodecyl mercaptan and octadecene according to a molar volume ratio of 4 mmol:4 ml:2 ml:6 ml, and ultrasonically treat for 30 min at a frequency of 4000 Hz to prepare the zinc acetate precursor solution;

[0039] The zinc stearate precursor solution is prepared by the following method: mix zinc stearate, 1-dodecyl mercaptan and octadecene according to a molar volume ratio of 4 mmol:2 ml:6 ml, and ultrasonically treat for 30 min at a frequency of 4000 Hz to prepare the zinc stearate precursor solution.

[0040] Example 2

[0041] The application discloses an environment-friendly copper-gallium-chalcogenide-zinc sulfide core-shell quantum dot and a preparation method thereof.

[0042] (1) 0.4 mmol of gallium acetylacetonate, 0.1 mmol of cuprous iodide, 2 ml of oleylamine and 0.2 ml of 1-dodecyl mercaptan are placed into a 50 ml three-necked flask, and a heating jacket with a magnetic stirrer is used for heating, and the temperature is raised to 115 DEG C under nitrogen blowing, then the three-necked flask is placed in a nitrogen gas environment and degassed for 60 min, then the temperature is continuously raised to 175 DEG C, and 1.5 ml of a sulfur precursor solution is added into the three-necked flask, and the reaction is carried out for 5 min to form a CGS core quantum dot solution;

[0043] The sulfur precursor solution is prepared by mixing sulfur powder and octadecene according to a molar volume ratio of 2 mmol:4 ml, and ultrasonic treatment is carried out at a frequency of 4000 Hz for 30 min.

[0044] (2) 4 ml of the CGS core quantum dot solution in the step (1) is heated to 215 DEG C, 5 ml of a zinc acetate precursor solution is added into the three-necked flask at a speed of 0.8 ml / min and stirred for 30 min, then the temperature is continuously raised to 255 DEG C, 3 ml of a zinc stearate precursor solution is added into the three-necked flask at a speed of 0.8 ml / min and stirred for 1 h, after the reaction is completed, water bath quenching is carried out, the mixed solution is mixed with toluene according to a volume ratio of 1:3, then centrifugation is carried out at a speed of 3000 r / min, the supernatant is taken, the supernatant is mixed with ethanol according to a volume ratio of 1:2, centrifugation is carried out at a speed of 12000 r / min, the precipitate is collected, and air drying is carried out to obtain the CuGaS2 / ZnS core-shell quantum dot.

[0045] The zinc acetate precursor solution is prepared by mixing anhydrous zinc acetate, oleic acid, 1-dodecyl mercaptan and octadecene according to a molar volume ratio of 3 mmol:3 ml:1 ml:5 ml, and ultrasonic treatment is carried out at a frequency of 4000 Hz for 30 min.

[0046] The zinc stearate precursor solution is prepared by mixing zinc stearate, 1-dodecyl mercaptan and octadecene according to a molar volume ratio of 3 mmol:1 ml:5 ml, and ultrasonic treatment is carried out at a frequency of 4000 Hz for 30 min.

[0047] Example 3

[0048] The application discloses an environment-friendly copper-gallium-chalcogenide-zinc sulfide core-shell quantum dot and a preparation method thereof.

[0049] (1) Put 0.6 mmol of acetylacetone gallium, 0.15 mmol of cuprous iodide, 3 ml of oleylamine and 0.3 ml of 1-dodecyl mercaptan into a 50 ml three-necked flask and heat using a heating mantle with a magnetic stirrer, and under nitrogen purging, warm to 130℃, then degassed for 60 min in a nitrogen gas environment, then continue to warm to 190℃, and add 2.5 ml of a sulfur precursor solution thereto, react for 5 min to form a CGS core quantum dot solution;

[0050] The sulfur precursor solution is prepared by mixing sulfur powder and octadecene in a molar volume ratio of 4 mmol:2 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz to obtain the CGS core quantum dot solution.

[0051] (2) Warm 6 ml of the CGS core quantum dot solution in step (1) to 220℃, and add 7 ml of a zinc acetate precursor solution thereto at a rate of 1 ml / min and stir for 30 min, then continue to warm to 250℃, and add 5 ml of a zinc stearate precursor solution thereto at a rate of 1.2 ml / min and stir for 1 h, then quench in a water bath after the reaction is complete, mix the mixed solution with toluene in a volume ratio of 1:3, then centrifuge at a speed of 3000 r / min, take the supernatant, mix the supernatant with ethanol in a volume ratio of 1:2, and centrifuge at a speed of 12000 r / min, collect the precipitate, and air dry to obtain CuGaS2 / ZnS core-shell quantum dots.

[0052] The zinc acetate precursor solution is prepared by mixing anhydrous zinc acetate, oleic acid, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 5 mmol:5 ml:3 ml:7 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz.

[0053] The zinc stearate precursor solution is prepared by mixing zinc stearate, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 5 mmol:3 ml:7 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz.

[0054] Example 4

[0055] An environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dot, and a preparation method thereof, the preparation method comprising the following steps:

[0056] (1) Put 0.125 mmol of acetylacetone gallium, 0.06 mmol of cuprous iodide, 0.125 ml of indium acetate, 2.5 ml of oleylamine and 0.25 ml of 1-dodecyl mercaptan into a 50 ml three-necked flask and heat using a heating mantle with a magnetic stirrer, and under nitrogen purging, raise the temperature to 120℃, then place it in a nitrogen gas environment and degas for 60 min, then continue to raise the temperature to 180℃, and add 2 ml of sulfur precursor solution thereto, react for 5 min to form a CGIS core quantum dot solution;

[0057] The sulfur precursor solution is prepared by mixing sulfur powder and octadecene in a molar volume ratio of 4 mmol:4 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz;

[0058] (2) Raise the CGIS core quantum dot solution in step (1) to 210℃, and add 6 ml of zinc acetate precursor solution thereto at a speed of 1 ml / min and stir for 30 min, then continue to raise the temperature to 250℃, and add 4 ml of zinc stearate precursor solution thereto at a speed of 1 ml / min and stir for 1 h, after the reaction is completed, quench with a water bath, mix the mixed solution with toluene in a volume ratio of 1:3, then centrifuge at a speed of 3000 r / min, take the supernatant, mix the supernatant with ethanol in a volume ratio of 1:2, centrifuge at a speed of 12000 r / min, collect the precipitate, and air dry to obtain CuGaInS2 / ZnS core-shell quantum dots;

[0059] The zinc acetate precursor solution is prepared by mixing anhydrous zinc acetate, oleic acid, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 4 mmol:4 ml:2 ml:6 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz;

[0060] The zinc stearate precursor solution is prepared by mixing zinc stearate, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 4 mmol:2 ml:6 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz.

[0061] Comparative Example 1

[0062] An environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dot, and a preparation method thereof, the preparation method comprising the following steps:

[0063] (1) Put 0.5 mmol of acetylacetone gallium, 0.125 mmol of cuprous iodide, 2.5 ml of oleylamine and 0.25 ml of 1-dodecyl mercaptan into a 50 ml three-necked flask and heat using a heating mantle with a magnetic stirrer, and under nitrogen purging, warm to 120°C, then degas for 60 min in a nitrogen gas environment, then continue to warm to 180°C, and add 2 ml of a sulfur precursor solution thereto, and react for 5 min to form a CGS core quantum dot solution;

[0064] The sulfur precursor solution is prepared by mixing sulfur powder and octadecene in a molar volume ratio of 4 mmol:4 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz to obtain the CGS core quantum dot solution.

[0065] (2) Warm 5 ml of the CGS core quantum dot solution in step (1) to 210°C, and add 10 ml of a zinc acetate precursor solution thereto at a rate of 1 ml / min and stir for 30 min, then quench in a water bath after the reaction is complete, mix the mixed solution with toluene in a volume ratio of 1:3, then centrifuge at a speed of 3000 r / min, take the supernatant, mix the supernatant with ethanol in a volume ratio of 1:2, and centrifuge at a speed of 12000 r / min, collect the precipitate, and air dry to obtain CuGaS2 / ZnS core-shell quantum dots.

[0066] The zinc acetate precursor solution is prepared by mixing anhydrous zinc acetate, oleic acid, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 4 mmol:4 ml:2 ml:6 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz.

[0067] The zinc stearate precursor solution is prepared by mixing zinc stearate, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 4 mmol:2 ml:6 ml, and ultrasonic treatment for 30 min at a frequency of 4000 Hz.

[0068] Experimental Examples

[0069] The quantum dot materials in Examples 1 and 4 are taken as examples for microscopic detection of the above quantum dot materials, and the specific detection results are shown in Figures 1-2 ;

[0070] Figure 1 The transmission electron microscope image of the quantum dots in Example 1 is shown in Figure 2 The transmission electron microscope image of the quantum dots in Example 4 is shown in Figures 1-2 It can be seen that the size distribution of the prepared quantum dot materials is uniform, and the average particle size is 2 nm.

[0071] As an example of the quantum dot material in Examples 1 and 4, a solar energy fluorescent concentrator with a size of 5 cm*5 cm*0.5 cm was prepared using the quantum dot material in Examples 1, 4 and Comparative Example 1, respectively, according to the following method: 4 ml of the prepared copper-gallium-sulfur chalcogenide zinc sulfide core-shell quantum dots were dissolved in 6 ml of toluene, and a clear solution was obtained by ultrasonic treatment at a frequency of 4000 Hz for 10 min. The solution was drop-coated on the surface of a glass plate, and then dried at room temperature to evaporate all the solvents, thereby obtaining a fluorescent solar concentrator.

[0072] A tandem fluorescent solar concentrator was constructed using the quantum dot material in Examples 1 and 4, according to the following method: the quantum dot material solution in Example 4 prepared by the above method was drop-coated on the bottom layer of a glass plate for absorbing the long-wavelength part of the solar spectrum, dried, and then a polymethyl lauryl methacrylate-ethylene glycol dimethacrylate layer was drop-coated on the surface of the bottom layer as a separation layer with a thickness of 0.3 mm, and then the quantum dot material solution in Example 1 prepared by the above method was drop-coated on the surface of the separation layer as a top layer for absorbing the short-wavelength part of the solar spectrum. The specific physical diagram is shown in Figure 3 ;

[0073] A fluorescent solar concentrator-solar cell photoelectric conversion test system was constructed to test the optical efficiency of the quantum dots. A standard AM1.5G solar simulator was used as a light source during the test, and the specific test results are shown in Table 1 and Figure 4 :

[0074] Table 1: Performance test data of solar energy fluorescent concentrator

[0075] Fill Factor (FF) Optical efficiency (η opt )]]> Example 1 62.6％ 2.91％ Example 4 70.0％ 6.20％ Comparative Example 1 61.4％ 1.31％ Tandem Fluorescent Solar Concentrator 71.1％ 8.50％

[0076] As can be seen from the data in the above table, the performance of the fluorescent solar concentrator constructed using the quantum dot material prepared in Examples 1 and 4 is significantly improved compared to the fluorescent solar concentrator constructed using the quantum dot material in Comparative Example 1, and the construction of the tandem structure further significantly improves the optical efficiency.

[0077] Figure 3 A physical diagram of the fluorescent solar concentrator is shown in the following figure, in which Figure 3 the left figure is a solar concentrator constructed using the quantum dots in Example 1, Figure 3 the middle figure is a fluorescent solar concentrator constructed using the quantum dots in Example 4, Figure 3 and the right figure is a tandem fluorescent solar concentrator constructed using the quantum dot materials in Examples 1 and 4.

[0078] Figure 4Performance test chart of different fluorescent solar concentrator-standard solar cell; it can be seen that the fluorescent solar concentrator-standard solar cell in Example 1: V oc : 1.75 V, J sc : 0.04 mA / cm 2 , FF: 64.1%, η opt : 2.91%; the fluorescent solar concentrator-standard solar cell in Example 4: V oc : 1.85 V, J sc : 0.09 mA / cm 2 , FF: 70.0%, η opt : 6.20%; the fluorescent solar concentrator-standard solar cell in Comparative Example 1: V oc : 1.55 V, J sc : 0.02 mA / cm 2 , FF: 61.4%, η opt : 1.31%; the series fluorescent solar concentrator-standard solar cell in Example 1 and Example 4: V oc : 1.95 V, J sc : 0.16 mA / cm 2 , FF: 71.1%, η opt : 8.50%.

Claims

1. A method for preparing environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots, characterized in that, Includes the following steps: (1) Mix gallium source, copper source, oleylamine and 1-dodecyl mercaptan, heat the mixture to 115-130°C in a nitrogen environment, then degas it in a nitrogen environment, then continue to heat it to 175-190°C, and add sulfur precursor solution to it. React to obtain quantum dot solution. (2) Heat the quantum dot solution in step (1) to 210-220℃, add zinc acetate precursor solution dropwise and stir to react, then continue to heat to 250-260℃, add zinc stearate precursor solution dropwise and stir to react, after the reaction is completed, quench in water bath and purify to obtain copper gallium sulfide / zinc sulfide core-shell quantum dots; Step (1) also contains an indium source, a gallium source, a copper source, an indium source, an oleylamine, a 1-dodecyl mercaptan, and a sulfur precursor solution with a molar volume ratio of 0.1-0.15 mmol: 0.04-0.08 mmol: 0.1-0.15 mmol: 2-3 ml: 0.2-0.3 ml: 1.5-2.5 ml, and finally copper gallium indium sulfide / zinc sulfide core-shell quantum dots are obtained; The zinc acetate precursor solution was prepared by the following method: anhydrous zinc acetate, oleic acid, 1-dodecylthiol, and octadecene were mixed in a molar volume ratio of 4mmol:4ml:2ml:6ml or 3mmol:3ml:1ml:5ml or 5mmol:5ml:3ml:7ml, and ultrasonicated at 4000Hz for 30min. The zinc stearate precursor solution was prepared by the following method: zinc stearate, 1-dodecyl mercaptan, and octadecene were mixed in a molar volume ratio of 4 mmol:2 ml:6 ml, 3 mmol:1 ml:5 ml, or 5 mmol:3 ml:7 ml, and ultrasonicated at 4000 Hz for 30 min.

2. The method for preparing environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots as described in claim 1, characterized in that, In step (1), the molar volume ratio of gallium source, copper source, oleylamine, 1-dodecyl mercaptan and sulfur precursor solution is 0.4-0.6 mmol: 0.1-0.15 mmol: 2-3 ml: 0.2-0.3 ml: 1.5-2.5 ml.

3. The method for preparing environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots as described in claim 1, characterized in that, In step (1), the gallium source is gallium acetylacetonate, the copper source is cuprous iodide, and the indium source is indium acetate.

4. The method for preparing environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots as described in claim 1, characterized in that, The sulfur precursor solution in step (1) is prepared by mixing sulfur powder and octadecene in a molar volume ratio of 1-2 mmol: 1-2 ml. The zinc acetate precursor solution in step (2) is prepared by the following method: anhydrous zinc acetate, oleic acid, 1-dodecyl mercaptan and octadecene are mixed in a molar volume ratio of 3-5 mmol: 3-5 ml: 1-3 ml: 5-7 ml to obtain the solution. In step (2), the zinc stearate precursor solution is prepared by mixing zinc stearate, 1-dodecyl mercaptan and octadecene in a molar volume ratio of 3-5 mmol: 1-3 ml: 5-7 ml.

5. The method for preparing environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots as described in claim 1, characterized in that, In step (2), the volume ratio of quantum dot solution, zinc acetate precursor solution and zinc stearate precursor solution is 4-6 ml: 5-7 ml: 3-5 ml.

6. The method for preparing environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots as described in claim 1, characterized in that, In step (2), the dropping rate of the zinc acetate precursor solution and the zinc stearate precursor solution is 0.8-1.2 ml / min.

7. An environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dot, characterized in that, The quantum dots include copper gallium sulfide / zinc sulfide core-shell quantum dots and / or copper gallium indium sulfide / zinc sulfide core-shell quantum dots, wherein the quantum dots are prepared by any one of claims 1-6.

8. The application of the environmentally friendly copper gallium chalcogenide zinc sulfide core-shell quantum dots as described in claim 7 in the preparation of fluorescent solar concentrators.

9. The application as described in claim 8, characterized in that, Copper gallium sulfide / zinc sulfide core-shell quantum dots are used as the top layer of the fluorescent solar concentrator, and copper gallium indium sulfide / zinc sulfide core-shell quantum dots are used as the bottom layer of the fluorescent solar concentrator. A polymer separator is set between the two layers.

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