Silver-bismuth-sulfur quantum dot thin film and solar cell, and preparation methods therefor
Patent Information
- Application Number
- PCT/CN2025/089080
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2026-10-22
Smart Images
Figure CN2025089080_22102026_PF_FP_ABST
Abstract
Description
A silver bismuth sulfur quantum dot thin film, a solar cell and its preparation method Technical Field
[0001] This invention relates to the field of photovoltaic technology, and in particular to a silver bismuth sulfur quantum dot thin film, a solar cell, and a method for preparing the same. Background Technology
[0002] Against the backdrop of advocating carbon neutrality, the development of clean and low-carbon new energy technologies is of great significance. In the photovoltaic field, although crystalline silicon solar cells are already in mass production, their fabrication process is complex. Colloidal quantum dots, due to their cost-effective solution processability and excellent photoelectric properties, have attracted considerable attention for next-generation photovoltaic technologies. In research on novel solar cells, narrow-bandgap heavy metal compound semiconductors such as PbS, PbSe, and CdS, as well as lead-based halide perovskite materials, are often chosen as the active layer. However, their synthesis conditions are demanding and environmentally harmful, necessitating green and non-toxic alternatives. Silver bismuth sulfide (AgBiS2) quantum dots are non-toxic, have a bandgap matching solar spectrum, excellent electrical properties, and good stability, making them suitable as a replacement for the aforementioned heavy metal compounds.
[0003] The synthesis of AgBiS2 quantum dots typically employs a thermal injection method. This method requires the introduction of insulating oleic acid ligands, making them unsuitable for direct use in photovoltaic devices. Ligand exchange and other processes are necessary to improve carrier transport and passivate surface defects. However, existing ligand exchange methods have drawbacks: in solid-state ligand exchange, proton solvents participate in the desorption of the original ligands, easily inducing numerous defect states on the quantum dot surface, affecting the overall performance of the solar cell; while liquid-phase ligand exchange avoids the use of proton solvents, the introduced short-chain ligands reduce the stability of the quantum dot dispersion, leading to quantum dot aggregation, affecting film formation, and consequently impacting device performance. Summary of the Invention
[0004] To address the aforementioned shortcomings, this invention proposes a silver bismuth sulfur quantum dot thin film, a solar cell, and a method for preparing the same.
[0005] The technical solution adopted in this invention is a method for preparing silver bismuth-sulfur quantum dot thin films, comprising the following steps:
[0006] S100, Preparation of silver bismuth sulfur quantum dot dispersion;
[0007] S200. Prepare a hybrid ligand dispersion, wherein the hybrid ligand dispersion comprises an organic ligand containing a coordinating group and at least one inorganic salt;
[0008] S300. An electron transport layer is prepared on an ITO glass substrate, and the silver bismuth sulfur quantum dot dispersion is spin-coated onto the electron transport layer to form a silver bismuth sulfur quantum dot layer.
[0009] S400. The hybrid ligand dispersion is dropped onto the silver bismuth sulfur quantum dot layer, allowed to stand, and then dried and rinsed to remove excess hybrid ligand dispersion.
[0010] Preferably, the organic ligand containing the coordinating group is a short-chain organic ligand containing a thiol group, and / or the inorganic salt is an alkali metal halide or an alkali metal thiocyanate.
[0011] Preferably, the thiol-containing short-chain organic ligand is 3-mercaptopropionic acid, the alkali metal halide is one of sodium chloride, potassium chloride, rubidium chloride, cesium chloride, sodium bromide, potassium bromide, rubidium bromide, cesium bromide, sodium iodide, potassium iodide, rubidium iodide, or cesium iodide, and the alkali metal thiocyanate is one of sodium thiocyanate, potassium thiocyanate, rubidium thiocyanate, or cesium thiocyanate.
[0012] Preferably, the concentration of the organic ligand containing the coordinating group is 1–20 μL / mL, and / or the concentration of the inorganic salt is 0.2–10 mg / mL.
[0013] Preferably, the hybrid ligand dispersion comprises an organic ligand containing a coordinating group and two or more inorganic salts.
[0014] Preferably, in step S400, the settling time is 10 to 60 seconds.
[0015] Preferably, step S400 is repeated 2 to 5 times.
[0016] The present invention also discloses a silver bismuth sulfur quantum dot thin film, which is prepared by the above-described preparation method.
[0017] This invention also discloses a method for preparing a silver bismuth-sulfur quantum dot solar cell, comprising the following steps:
[0018] A hole transport layer was prepared on the aforementioned silver bismuth sulfur quantum dot thin film;
[0019] A metal electrode is fabricated on the hole transport layer.
[0020] The present invention also discloses a silver bismuth sulfur quantum dot solar cell, which is prepared by the above-described preparation method.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] 1. The preparation method of the silver bismuth-sulfur quantum dot thin film in this invention employs an organic-inorganic hybrid ligand dispersion for ligand exchange. The organic ligands possess coordinating groups, enabling strong coordination with the quantum dot surface, preventing quantum dot aggregation due to oleic acid shedding, improving quantum dot film formation, and exhibiting better charge transport characteristics compared to traditional oleic acid ligands. Ions in the inorganic salt can fill defects on the quantum dot surface, further passivating these defects. This organic-inorganic hybrid approach improves carrier transport between quantum dots while reducing surface defect states. The resulting AgBiS2 quantum dot thin film exhibits a higher absorption coefficient, improves AgBiS2 quantum dot film formation, and increases the current density of the device, thereby enhancing the efficiency of AgBiS2 quantum dot solar cells.
[0023] 2. Compared with the liquid-phase ligand exchange process for AgBiS2 quantum dot films, the in-situ ligand passivation process has the advantages of simple operation and more stable AgBiS2 quantum dot materials. Attached Figure Description
[0024] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:
[0025] Figure 1 is a flowchart of the preparation method of silver bismuth sulfur quantum dot thin films;
[0026] Figure 2 is a flowchart of the technical solution of the present invention;
[0027] Figure 3 is a schematic diagram of the structure of AgBiS2 quantum dot solar cell;
[0028] Figure 4 is the X-ray diffraction pattern of AgBiS2 quantum dots synthesized by thermal injection.
[0029] Figure 5 is a transmission electron microscope image of AgBiS2 quantum dots synthesized by hot injection method;
[0030] Figure 6 shows the UV-Vis absorption spectra of AgBiS2 quantum dot films after treatment with organic ligand 3-MPA or organic-inorganic hybrid ligands (3-MPA&NaSCN; 3-MPA&NaBr; 3-MPA&NaSCN&NaBr).
[0031] Figure 7 is a scanning electron microscope image of the AgBiS2 quantum dot film;
[0032] Figure 8 shows the JV characteristic curves of AgBiS2 quantum dot solar cells. Detailed Implementation
[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0034] In one embodiment, a method for preparing a silver bismuth-sulfur quantum dot thin film, as shown in Figure 1, includes the following steps:
[0035] S100, prepare silver bismuth sulfur quantum dot dispersion.
[0036] Specifically:
[0037] S110. Preparation of hexamethyldisiloxane precursor solution. Hexamethyldisiloxane is added to octadecene and stirred until homogeneous.
[0038] S120. Silver acetate, bismuth acetate, octadecene, and oleic acid were added to the reaction flask, which was then connected to a double-row tube. The mixture was stirred and subjected to vacuum dehydration and deoxygenation at 100°C. Nitrogen gas was then introduced into the reaction flask. Finally, the hexamethyldisiloxane precursor solution from step 1 was rapidly injected into the reaction mixture, and the temperature of the reaction flask was lowered to room temperature using an ice-water bath. The reaction was then continued with stirring at room temperature.
[0039] S130. The AgBiS2 quantum dot product is removed and centrifuged, and then washed and purified with acetone. Finally, the washed and purified AgBiS2 quantum dots are dispersed in a toluene solution.
[0040] S200. Prepare a hybrid ligand dispersion, wherein the hybrid ligand dispersion comprises an organic ligand containing a coordinating group and at least one inorganic salt.
[0041] Specifically, at least one inorganic salt (such as sodium bromide, sodium iodide, sodium thiocyanate, etc.) and an organic ligand containing a coordinating group, such as 3-mercaptopropionic acid (3-MPA), are added to a methanol solution and stirred until completely dissolved.
[0042] S300. An electron transport layer is prepared on an ITO glass substrate, and the silver bismuth sulfur quantum dot dispersion is spin-coated onto the electron transport layer to form a silver bismuth sulfur quantum dot layer.
[0043] Specifically:
[0044] S310. Cleaning the indium tin oxide (ITO) glass substrate. The ITO glass substrate is ultrasonically cleaned sequentially with deionized water, acetone, and isopropanol, and then dried before being cleaned with ultraviolet ozone.
[0045] S320. Preparation of the electron transport layer. A tin dioxide aqueous dispersion is spin-coated onto the surface of ITO glass and then annealed to form a tin dioxide layer, i.e., the electron transport layer.
[0046] S330. Spin-coat the AgBiS2 quantum dot dispersion onto the tin dioxide layer obtained in step S320 to form a silver bismuth sulfur quantum dot layer.
[0047] S400. The hybrid ligand dispersion is added dropwise onto the silver bismuth-sulfur quantum dot layer. After standing, the excess hybrid ligand dispersion is spin-coated and rinsed off. Specifically, an appropriate amount of hybrid ligand dispersion is added dropwise onto the AgBiS2 quantum dot layer until it is fully covered. After standing, the excess liquid is spin-coated and dried off, and an appropriate amount of methanol and toluene are added dropwise to rinse off the excess ligands.
[0048] Furthermore, after S400, the process also includes: S500, transferring the AgBiS2 quantum dot film obtained in step S400 into a nitrogen glove box and performing annealing treatment.
[0049] The method for preparing the silver bismuth-sulfur quantum dot thin film in this embodiment employs an organic-inorganic hybrid ligand dispersion for ligand exchange. The organic ligands possess coordinating groups, enabling strong coordination with the quantum dot surface, preventing quantum dot aggregation due to oleic acid shedding, improving quantum dot film formation, and exhibiting better charge transport characteristics compared to traditional oleic acid ligands. Ions in the inorganic salt can fill defects on the quantum dot surface, further passivating these defects. This organic-inorganic hybrid approach improves carrier transport between quantum dots while reducing surface defect states. The resulting AgBiS2 quantum dot thin film exhibits a higher absorption coefficient, improved AgBiS2 quantum dot film formation, and increased device current density, thereby enhancing the efficiency of AgBiS2 quantum dot solar cells.
[0050] In one embodiment, the organic ligand containing the coordinating group is a short-chain organic ligand containing a thiol group. The thiol group (-SH) can react with metal ions (Ag) on the surface of AgBiS2 quantum dots. + Bi 3+ This allows for the formation of coordination bonds; the shorter molecular chains prevent quantum dot aggregation caused by long chains, thus improving film formation and carrier transport efficiency. Furthermore, the thiol-containing short-chain organic ligand is 3-mercaptopropionic acid, etc. 3-mercaptopropionic acid has good solubility in common solvents, making it easy to prepare hybrid ligand dispersions. It also exhibits high reactivity, allowing for ligand exchange reactions with the quantum dot surface under mild conditions, which is beneficial for process control and large-scale production.
[0051] In one embodiment, the inorganic salt is an alkali metal halide or an alkali metal thiocyanate. Alkali metal salts have high solubility, low toxicity, and can form stable coordination with quantum dot surface defects (such as sulfur vacancies). Further, the alkali metal halide is sodium chloride, potassium chloride, rubidium chloride, cesium chloride, sodium bromide, potassium bromide, rubidium bromide, cesium bromide, sodium iodide, potassium iodide, rubidium iodide, or cesium iodide, etc., and the alkali metal thiocyanate is sodium thiocyanate, potassium thiocyanate, rubidium thiocyanate, or cesium thiocyanate, etc. These alkali metal halides and alkali metal thiocyanates have the advantages of wide availability, low cost, stable chemical properties, and the ability to effectively improve the performance of silver bismuth sulfur quantum dot films.
[0052] In one embodiment, the concentration of the organic ligand containing the coordinating group is 1–20 μL / mL, which ensures that there are enough ligands to exchange with the quantum dot surface, effectively replacing the original oleic acid ligand, improving the surface properties of the quantum dot, promoting carrier transport, and at the same time avoiding excessive modification of the quantum dot surface due to excessive ligand concentration, which would affect the carrier transport efficiency.
[0053] Furthermore, the concentration of inorganic salt is 0.2–10 mg / mL, which can not only allow halide ions or thiocyanate ions to fully fill the defects on the quantum dot surface and play a good passivation role, but also work synergistically with organic ligands to prevent problems such as incomplete passivation of surface defects caused by excessively high or low inorganic salt concentrations, thereby improving the quality and performance of quantum dot films.
[0054] In one embodiment, the hybrid ligand dispersion comprises an organic ligand containing a coordinating group and two or more inorganic salts. Ions from different inorganic salts can modify and passivate the quantum dot surface from various perspectives. The combined effect of multiple ions can more comprehensively fill surface defects, more finely regulate the charge distribution and chemical environment of the quantum dot surface, and more effectively improve the surface properties of quantum dots than a single inorganic salt, thereby increasing carrier transport efficiency and reducing carrier recombination. A more complex synergistic effect exists between multiple inorganic salts and the organic ligand containing a coordinating group, enabling the formation of a more stable coating structure on the quantum dot surface.
[0055] In one embodiment, the settling time in step S400 is 10–60 seconds. If the settling time is too short, the ligands may not be able to fully bind to the quantum dot surface, resulting in poor passivation. If the settling time is too long, it may cause some side reactions or adversely affect the already formed passivation layer. A settling time of 10–60 seconds can better avoid these problems.
[0056] In one embodiment, step S400 is repeated 2 to 5 times. Each time an organic-inorganic hybrid ligand solution is added, the ligand molecules and inorganic salts form a new passivation layer on the quantum dot surface. After repeating the operation 2 to 5 times, the multilayer ligands and salts gradually cover the quantum dot surface, increasing the total effective thickness of the film (including the quantum dot layer and the passivation layer), and ultimately improving the performance of the AgBiS2 quantum dot solar cell.
[0057] In one embodiment, a silver bismuth-sulfur quantum dot thin film is prepared by the preparation method described in the above embodiment. This invention achieves in-situ passivation of AgBiS2 quantum dot thin films using organic-inorganic hybrid ligands by introducing inorganic ligands. When the surface oleic acid ligands are desorbed by a proton solvent and other short-chain ligands are introduced, the ions in the inorganic ligands can simultaneously passivate surface defects in situ, ensuring excellent film-forming properties of the AgBiS2 quantum dot thin film, thereby achieving high-efficiency AgBiS2 quantum dot solar cells.
[0058] In one embodiment, a method for preparing a silver bismuth sulfur quantum dot solar cell includes the following steps: preparing a hole transport layer on the silver bismuth sulfur quantum dot thin film in the above embodiment; and preparing a metal electrode on the hole transport layer.
[0059] Specifically, step 1: Preparation of hole transport layer 1. Poly(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA) is dissolved in toluene solution and spin-coated onto AgBiS2 quantum dot film passivated by organic-inorganic hybrid ligands to form hole transport layer.
[0060] Step 2: Fabrication of hole transport layer 2. Under a vacuum of 5 × 10⁻⁶... -4 Molybdenum oxide hole transport layer is deposited by vapor deposition in a vacuum environment below Pa.
[0061] Step 3: Fabrication of the metal electrode. Under a vacuum of 5 × 10⁻⁶... -4 Silver metal electrodes are deposited by vapor deposition in a vacuum environment below Pa.
[0062] In one embodiment, a silver bismuth-sulfur quantum dot solar cell is prepared by the preparation method described in the above embodiment. In-situ passivation of the AgBiS2 quantum dot film using organic-inorganic hybrid ligands can effectively improve the light absorption coefficient of the AgBiS2 quantum dots and also effectively enhance the short-circuit current density and photoelectric conversion efficiency of the AgBiS2 quantum dot solar cell.
[0063] The following is a more specific embodiment, see Figure 2.
[0064] 1. Synthesis of AgBiS2 quantum dots.
[0065] Step 1: Preparation of hexamethyldisiloxane precursor solution. Add 845 μL of hexamethyldisiloxane to 5 mL of octadecene and stir until homogeneous.
[0066] Step 2: Add 3.2 mmol of silver acetate, 4 mmol of bismuth acetate, 15 mL of octadecene, and 24 mL of oleic acid to the reaction flask, connect the flask to a double-row tube, and stir and vacuum dehydrate and deoxygenate at 100°C for 2 hours. Then, purge the reaction flask with nitrogen. Finally, rapidly inject the hexamethyldisiloxane precursor solution from Step 1 into the reaction, cool the reaction flask to room temperature using an ice-water bath, and continue stirring at room temperature for 1 hour.
[0067] Step 3: After centrifuging the AgBiS2 quantum dot product, collect the precipitate and redisperse it in toluene solution. Add an equal volume of acetone to wash and purify the AgBiS2 quantum dots, then centrifuge again. Finally, disperse the washed and purified AgBiS2 quantum dots in toluene solution to a concentration of 20 mg / mL.
[0068] 2. In-situ passivation of AgBiS2 quantum dot films using organic-inorganic hybrid ligands.
[0069] Step 1: Prepare an organic-inorganic hybrid ligand dispersion. Add 5 mg of inorganic ligand (such as sodium bromide, sodium iodide, sodium thiocyanate, etc.) and 50 μL of 3-mercaptopropionic acid to 5 mL of methanol solution and stir until completely dissolved.
[0070] Step 2: Cleaning the indium tin oxide (ITO) glass substrate. The ITO glass substrate is ultrasonically cleaned sequentially with deionized water, acetone, and isopropanol. After drying, it is then cleaned with ultraviolet ozone.
[0071] Step 3: Prepare the electron transport layer. Spin-coat a 12% (w / w) tin dioxide aqueous dispersion onto the ITO glass surface and anneal at 270°C for 15 minutes.
[0072] Step 4: In-situ passivation of the AgBiS2 quantum dot film using organic-inorganic hybrid ligands. The AgBiS2 quantum dot dispersion was spin-coated onto the tin dioxide layer obtained in Step 3. Then, an appropriate amount of organic ligand or organic-inorganic hybrid ligand dispersion was drop-added onto the AgBiS2 quantum dot layer until it was fully covered. After standing for 45 seconds, excess liquid was spin-coated and dried, and then excess ligand was rinsed off with appropriate amounts of methanol and toluene, respectively. This step was repeated twice.
[0073] Step 5: Transfer the AgBiS2 quantum dot film obtained in Step 4 into a nitrogen glove box and anneal it at 115°C for 10 minutes.
[0074] 3. Fabrication of high-efficiency AgBiS2 quantum dot solar cells.
[0075] Step 1: Preparation of hole transport layer 1. Poly(4-phenyl)(2,4,6-trimethylphenyl)amine was dissolved in toluene solution at a concentration of 2 mg / mL and spin-coated onto AgBiS2 quantum dot film passivated with organic-inorganic hybrid ligands to form hole transport layer 1.
[0076] Step 2: Fabrication of hole transport layer 2. Under a vacuum of 5 × 10⁻⁶... -4 Molybdenum oxide 3nm was deposited in a vacuum environment below Pa to form a hole transport layer 2.
[0077] Step 3: Fabrication of the metal electrode. Under a vacuum of 5 × 10⁻⁶... -4 A 120nm silver metal electrode is deposited in a vacuum environment below Pa.
[0078] The AgBiS2 quantum dot solar cell prepared in this invention achieves a photoelectric conversion efficiency of 8.52% and an efficiency of 27.49 mA / cm². 2 The short-circuit current density.
[0079] The following is a more specific example.
[0080] The synthesized AgBiS2 quantum dots and AgBiS2 quantum dot solar cell devices with different ligands in situ passivated were tested and characterized. The structure of the AgBiS2 quantum dot solar cell device is shown in Figure 3. From bottom to top, it consists of an ITO glass substrate, an electron transport layer, an AgBiS2 quantum dot layer (thin film), a hole transport layer, and a metal electrode. The different ligands include: the organic ligand 3-MPA or organic-inorganic hybrid ligands (3-MPA&NaSCN; 3-MPA&NaBr; 3-MPA&NaSCN&NaBr). Specifically, the organic ligand dispersion was prepared by adding the organic ligand 3-mercaptopropionic acid to a methanol solution and stirring until completely dissolved.
[0081] (1) X-ray Diffraction: The synthesized AgBiS2 quantum dots were characterized by X-ray diffraction, as shown in Figure 4. The horizontal axis (x-axis) represents the 2θ angle in degrees. The vertical axis (y-axis) represents the diffraction intensity. The figure clearly labels "AgBiS2 quantum dots," indicating that the tested sample is AgBiS2 quantum dot material. The black vertical lines in the figure represent the diffraction peak positions of the PDF00-057-0604 standard card. The gray peaks in the spectrum are the actual diffraction peaks of the AgBiS2 quantum dot sample. The phase of the synthesized AgBiS2 quantum dots can be determined by comparing it with the XRD standard card PDF00-057-0604.
[0082] (2) Transmission electron microscopy: The synthesized AgBiS2 quantum dots were characterized by transmission electron microscopy (TEM). See Figure 5. The "50nm" scale bar in the lower left corner of the image indicates the image scale and is used to measure the actual size of the quantum dots. It can be seen that the synthesized AgBiS2 quantum dots have good size dispersion.
[0083] (3) UV-Vis absorption spectroscopy: UV-Vis absorption spectra were measured for AgBiS2 quantum dot films in situ passivated with different ligands. See Figure 6, which shows the absorption spectrum of absorbance as a function of wavelength. The pristine curve represents the absorption spectrum of the original sample without additional treatment, serving as a reference. It can be seen that the absorption intensity of AgBiS2 quantum dot films in situ passivated with organic-inorganic hybrid ligands is significantly improved, with the AgBiS2 quantum dot film treated with 3-MPA&NaSCN&NaBr ligands exhibiting the highest absorbance.
[0084] (4) Scanning electron microscopy: Scanning electron microscopy was performed on AgBiS2 quantum dot films that were in situ passivated with different ligands, as shown in Figure 7. AgBiS2 quantum dot films that were in situ passivated with organic-inorganic hybrid ligands exhibited excellent film-forming properties.
[0085] (5) JV Performance Testing. The current-voltage (JV) performance of solar cells fabricated from AgBiS2 quantum dot films in situ passivated with different ligands was tested using a solar simulator. See Figure 8, which contains four sub-figures (a, b, c, d). Each sub-figure has two curves: a dashed line representing "Forward" and a solid line representing "Reverse," used to demonstrate the electrical characteristics of the device under different scanning directions. The table below shows the specific parameters of the solar cells corresponding to the AgBiS2 quantum dot films after different ligand treatments.
[0086] It is evident that the solar cells corresponding to AgBiS2 quantum dot films passivated in situ with organic-inorganic hybrid ligands exhibit higher short-circuit current density (Jsc), and also show improvements in open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE). Specifically, the solar cell device fabricated using AgBiS2 quantum dot films treated with 3MPa, NaSCN, and NaBr organic-inorganic hybrid ligands achieved a power conversion efficiency of 8.52% and a short-circuit current density of 27.49 mA / cm². 2 .
[0087] In the description of this specification, the use of terms such as "Embodiment 1," "this embodiment," or "in one embodiment" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example; moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in one or more embodiments or examples.
[0088] In the description of this specification, the terms "connection," "installation," "fixing," "setting," and "having" are interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0089] In the description of this specification, relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0090] The above description of the embodiments is intended to enable those skilled in the art to understand and apply the technology of this invention. Those skilled in the art can readily make various modifications to these examples and apply the general principles described herein to other embodiments without creative effort. Therefore, this invention is not limited to the above embodiments. Modifications in the following situations should be within the scope of protection of this invention: ① New technical solutions implemented based on the technical solution of this invention and combined with existing common knowledge, where the technical effects of the new technical solution do not exceed the technical effects of this invention; ② Equivalent substitutions of some features of the technical solution of this invention using known technology, resulting in the same technical effects as those of this invention; ③ Extendable technical solutions based on the technical solution of this invention, where the substantive content of the extended technical solution does not exceed the technical solution of this invention; ④ Equivalent transformations made using the content of this specification and drawings, directly or indirectly applied to other related technical fields.
Claims
1. A method for preparing a silver bismuth-sulfur quantum dot thin film, characterized in that, Includes the following steps: S100, Preparation of silver bismuth sulfur quantum dot dispersion; S200. Prepare a hybrid ligand dispersion, wherein the hybrid ligand dispersion comprises an organic ligand containing a coordinating group and at least one inorganic salt; S300. An electron transport layer is prepared on an ITO glass substrate, and the silver bismuth sulfur quantum dot dispersion is spin-coated onto the electron transport layer to form a silver bismuth sulfur quantum dot layer. S400. The hybrid ligand dispersion is dropped onto the silver bismuth sulfur quantum dot layer, allowed to stand, and then dried and rinsed to remove excess hybrid ligand dispersion.
2. The preparation method according to claim 1, characterized in that, The organic ligand containing the coordinating group is a short-chain organic ligand containing a thiol group, and / or the inorganic salt is an alkali metal halide or an alkali metal thiocyanate.
3. The preparation method according to claim 2, characterized in that, The thiol-containing short-chain organic ligand is 3-mercaptopropionic acid, the alkali metal halide is one of sodium chloride, potassium chloride, rubidium chloride, cesium chloride, sodium bromide, potassium bromide, rubidium bromide, cesium bromide, sodium iodide, potassium iodide, rubidium iodide, or cesium iodide, and the alkali metal thiocyanate is one of sodium thiocyanate, potassium thiocyanate, rubidium thiocyanate, or cesium thiocyanate.
4. The preparation method according to any one of claims 1-3, characterized in that, The concentration of the organic ligand containing the coordinating group is 1–20 μL / mL, and / or the concentration of the inorganic salt is 0.2–10 mg / mL.
5. The preparation method according to claim 4, characterized in that, The hybrid ligand dispersion comprises an organic ligand containing a coordinating group and two or more inorganic salts.
6. The preparation method according to claim 4, characterized in that, In step S400, the settling time is 10 to 60 seconds.
7. The preparation method according to claim 6, characterized in that, Step S400 is repeated 2 to 5 times.
8. A silver bismuth-sulfur quantum dot thin film, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.
9. A method for preparing a silver bismuth-sulfur quantum dot solar cell, characterized in that, Includes the following steps: A hole transport layer is prepared on the silver bismuth sulfur quantum dot film according to claim 8; A metal electrode is fabricated on the hole transport layer.
10. A silver bismuth-sulfur quantum dot solar cell, characterized in that, It is prepared by the preparation method described in claim 9.