Quantum dot detector preparation method based on one-step synthesis method
By synthesizing PbS colloidal quantum dots in a one-step process, the washing step is omitted and direct liquid-phase exchange is performed, which solves the problems of water and oxygen intrusion and ligand damage, thereby improving the performance of infrared detectors and their potential for large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUAZHONG UNIV OF SCI & TECH
- Filing Date
- 2025-12-30
- Publication Date
- 2026-05-08
AI Technical Summary
In the existing fabrication process of PbS colloidal quantum dot infrared detectors, the antisolvent precipitation-washing step leads to water and oxygen intrusion and ligand damage, resulting in deterioration of quantum dot performance. This process is characterized by high complexity, high cost, low efficiency, and poor performance.
A one-step synthesis method was used to synthesize 1550nm PbS colloidal quantum dots, omitting the cleaning step and directly performing liquid-phase exchange to avoid the introduction of water and oxygen and ligand damage, forming a uniform surface passivation layer and simplifying the process.
It improves the surface stability of quantum dots, increases carrier mobility and detector responsivity, reduces dark current, meets the requirements of high-sensitivity infrared detection, simplifies the process, reduces production costs, and is suitable for mass production.
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Figure CN122003074A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of infrared detector technology, and in particular relates to a method for preparing a quantum dot detector based on a one-step synthesis method. Background Technology
[0002] PbS colloidal quantum dots have become one of the core sensitive materials for next-generation infrared detectors due to their outstanding advantages such as solution processability, tunable bandgap (achieving near-infrared to mid-infrared response through quantum size effects), low raw material cost, and good compatibility with flexible substrates. Compared with traditional inorganic semiconductor infrared detectors (such as InGaAs and HgCdTe), PbS colloidal quantum dot infrared detectors do not require complex epitaxial growth equipment and can be prepared through low-cost processes such as spin coating and blade coating, showing great application potential in large-scale, lightweight infrared detection systems.
[0003] In the traditional fabrication process of PbS colloidal quantum dot infrared detectors, the synthesis and post-processing of PbS quantum dots are crucial steps determining device performance. Currently, the industry-standard PbS quantum dot synthesis process uses oleic acid as a ligand and octadecene as a solvent. PbS quantum dots are generated through a high-temperature injection reaction of precursors (such as lead acetate and hexamethyldisiloxane). After synthesis, to remove residual unreacted precursors, excess ligands, and solvent impurities, an antisolvent precipitation-washing step is usually required. This involves adding polar antisolvents such as isopropanol, acetone, or ethanol to the reaction solution, causing the PbS quantum dots to precipitate due to reduced solubility. The quantum dots are then collected by centrifugation and repeatedly washed with the antisolvent to obtain purified PbS quantum dot solids or redispersed quantum dot solutions, which are then used for subsequent ligand exchange (such as iodine ion passivation) and device fabrication.
[0004] In existing PbS quantum dot infrared detector fabrication processes, the antisolvent precipitation-washing step after synthesis presents a series of key problems: In this step, trace amounts of residual moisture from the antisolvent (such as isopropanol, acetone, or ethanol) and water and oxygen in the operating environment inevitably invade the PbS quantum dot surface, leading to surface hydroxylation and hydrogen-bonded water adsorption. This, in turn, triggers epitaxial fusion in subsequent processing, generating interband trap states, reducing carrier mobility, and increasing trap state density. Simultaneously, the strong polarity of the antisolvent disrupts the original oleic acid ligand coordination structure on the quantum dot surface, causing ligand detachment and surface defects, further degrading quantum dot performance. Existing PbS quantum dot infrared detectors suffer from high process complexity and equipment cost, low efficiency, and poor performance. Summary of the Invention
[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a one-step synthesis method for preparing quantum dot detectors. This method omits the quantum dot cleaning step after synthesizing 1550nm PbS colloidal quantum dots using a hot-injection method, and directly performs liquid-phase exchange, thereby avoiding the introduction of water and oxygen and ligand damage from the source. This simplifies the process while ensuring the surface stability of the quantum dots, improving the performance of the infrared detector and its potential for large-scale production.
[0006] In a first aspect, this application provides a method for fabricating a quantum dot detector based on a one-step synthesis method, the method comprising: Provide substrate; A bottom electrode is fabricated on the substrate; A hole transport layer is prepared on the bottom electrode, the hole transport layer comprising a NiOx thin film and a PbS-EDT thin film; A quantum dot light-absorbing layer was prepared on the hole transport layer using a one-step synthesis method. The quantum dot light-absorbing layer comprises 1550 nm PbS CQD. An electron transport layer is fabricated on a quantum dot light-absorbing layer, the electron transport layer comprising C 60 film and film; A top electrode is fabricated on the electron transport layer.
[0007] According to one embodiment of this application, the fabrication of the bottom electrode includes: Sn-doped As a target material; Using a DC power supply as the excitation source, a sputtering gas pressure of 0.3 Pa, and argon as the ionization gas, while reducing the sputtering power to 33 W, the bottom electrode was obtained.
[0008] According to one embodiment of this application, the preparation of the hole transport layer includes the preparation of a NiOx thin film and a PbS-EDT thin film, wherein the NiOx thin film is prepared by magnetron sputtering, including: Li-doped NiOx was used as the target material; Place the substrate in the vacuum chamber and evacuate until the base pressure is greater than [amount missing]. The sputtering pressure was controlled to 3.4 Pa by adjusting the gas flow rate. Argon gas at 100 sccm was introduced as an ionization gas to provide glow discharge. A 200 W radio frequency power supply was used as the excitation source to obtain NiOx thin films.
[0009] According to one embodiment of this application, the PbS-EDT thin film preparation includes: PbO was used as the lead source precursor, and PbS CQDs were prepared by thermal implantation of trimethylsilyl sulfide to obtain CQDs coated with OA. CQDs coated with OA were administered at a dose of 20 mg. Dissolved in n-octane, the solution was spin-coated onto the surface of a NiOx film at 2500 rpm. Then, it was post-treated with a 0.02% (v / v) EDT acetonitrile solution for 30 s to replace the oleic acid ligand with the EDT ligand. Finally, the surface was washed twice with acetonitrile solution. The above operation was repeated twice to obtain the PbS-EDT film.
[0010] According to one embodiment of this application, the preparation of the quantum dot light-absorbing layer includes PbS quantum dot synthesis, ligand exchange, and the preparation of a 1550nm PbS CQDs thin film. The PbS quantum dot synthesis includes: PbS colloidal quantum dots with an absorption peak of 1550 nm were synthesized by thermal injection method to obtain quantum dot stock solution.
[0011] According to one embodiment of this application, the ligand exchange includes: The synthesized quantum dot stock solution was directly mixed with the iodine bromide ligand exchange solution to perform liquid-phase ligand exchange.
[0012] According to one embodiment of this application, the preparation of the 1550nm PbS CQDs thin film includes: preparing a dispersant with a dispersant ratio of DMF:DMSO:BTA:3-aminopyridine = 350:250:370:30, and preparing a 400mg / ml PbS colloidal quantum dot ink, which is then spin-coated onto the device and annealed at 90°C for 15min to obtain a 1550nm PbS CQDs thin film.
[0013] According to one embodiment of this application, the fabrication of the electron transport layer includes... Thin film preparation and C 60 Thin film preparation, the The thin film was prepared using atomic layer deposition.
[0014] According to one embodiment of this application, the C 60 The thin film was prepared using a thermal evaporation process.
[0015] Secondly, this application provides a quantum dot detector based on a one-step synthesis method, wherein the quantum dot detector based on the one-step synthesis method comprises, from bottom to top, a substrate, a bottom electrode, a hole transport layer, a quantum dot light-absorbing layer, an electron transport layer, and a top electrode.
[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application.
[0017] The present invention provides a method for fabricating quantum dot detectors based on a one-step synthesis method, which has the following advantages over existing technologies: (1) This invention uses a one-step synthesis method to synthesize 1550nm PbS colloidal quantum dots, omitting the quantum dot cleaning step and directly performing liquid-phase exchange. This avoids the introduction of water and oxygen and ligand damage from the source. After omitting the cleaning step, the contact between residual water in the antisolvent and water vapor and oxygen in the operating environment and the quantum dot surface can be completely avoided. This effectively inhibits the chain reaction of surface hydroxylation-hydrogen bond water adsorption-quantum dot epitaxial fusion, blocks water and oxygen intrusion from the source, ensures the chemical stability of the quantum dot surface, significantly improves the core performance of the detector, and reduces the generation of interband trap states. Combined with direct liquid-phase ligand exchange, a uniform and dense surface passivation layer can be quickly formed, which significantly improves the carrier mobility and reduces the trap state density. Ultimately, this improves the responsivity and detectivity of the infrared detector and significantly reduces the dark current, meeting the requirements of high-sensitivity infrared detection. This simplifies the process while ensuring the stability of the quantum dot surface and improves the performance and large-scale production potential of the infrared detector.
[0018] (2) After the cleaning step is omitted in this invention, the original oleic acid ligands in the quantum dot synthesis system can maintain the complete coordination state and avoid the surface defects formed by ligand detachment; the subsequent direct liquid phase ligand exchange can achieve efficient and uniform ligand replacement on the basis of the original ligands, forming a continuous carrier transport channel, protecting the integrity of the ligands on the quantum dot surface, reducing surface defects, enhancing the carrier transport performance, further reducing the recombination loss of carriers at the interface, and improving the response speed and stability of the detector.
[0019] (3) By eliminating the cleaning steps such as anti-solvent precipitation, centrifugation, and repeated washing, the PbS quantum dots can directly enter the liquid phase ligand exchange step after synthesis, reducing 3-4 process steps and shortening the production cycle; greatly simplifying the process flow, reducing production costs, and facilitating large-scale mass production; at the same time, it does not require the use of a large amount of anti-solvent (such as isopropanol and acetone), reducing material consumption costs, and it does not require expensive equipment such as ultra-high vacuum or low humidity glove boxes to control water and oxygen in the cleaning process, significantly reducing equipment investment and maintenance costs, and is more suitable for the industrial large-scale, low-cost preparation of infrared detectors. Attached Figure Description
[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic flowchart of the quantum dot detector fabrication method based on one-step synthesis provided in the embodiments of this application; Figure 2 This is a schematic diagram of the preparation of a quantum dot light-absorbing layer using a one-step synthesis method provided in the embodiments of this application; Figure 3 This is a solvent diagram provided in the embodiments of this application for the theoretical synthesis of 1g of PbS CQDs; Figure 4 This is a film formation diagram of 1550nm PbS CQDs provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of a quantum dot detector based on a one-step synthesis method provided in an embodiment of this application. Detailed Implementation
[0021] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.
[0022] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0023] The following description, in conjunction with the accompanying drawings, details the fabrication method of the quantum dot detector based on the one-step synthesis method provided in this application through specific embodiments and application scenarios.
[0024] The post-synthesis cleaning step aims to purify the quantum dots, but research shows that this step is precisely the core cause of PbS quantum dot performance degradation and device instability decline, mainly due to the following key problems: (1) High risk of water and oxygen intrusion, leading to chemical degradation of the quantum dot surface. PbS quantum dots have extremely high surface sensitivity, with a high proportion of surface atoms, making them prone to interaction with water and oxygen in the environment. In existing cleaning processes, even after strict dehydration treatment, antisolvents (such as isopropanol and acetone) may still retain trace amounts of moisture; at the same time, the cleaning process needs to be carried out in a glove box or atmospheric environment, where water and oxygen will inevitably come into contact with the quantum dot surface, leading to a chain reaction: Surface hydroxylation: Water molecules are chemically adsorbed onto the surface of PbS quantum dots through dissociation, forming hydroxyl (-OH) groups. Especially on the polar {111} crystal plane of PbS quantum dots, the strong binding between Pb atoms and -OH makes it difficult for -OH to be completely removed through subsequent ligand exchange. Hydrogen-bonded water adsorption: Surface hydroxyl groups further adsorb water molecules from the environment through hydrogen bonds, forming "-OH+". ) n "The mixed phase, during subsequent device fabrication (such as annealing), will guide the quantum dots to undergo epitaxial fusion, thus destroying the discreteness of the quantum dots; Interband trap generation: Quantum dot fusion leads to disorder in its crystal structure, generating interband trap states, which significantly reduces carrier mobility, increases trap state density, and ultimately leads to a decrease in the responsivity and detectivity of infrared detectors, as well as a significant increase in dark current.
[0025] (2) Antisolvents damage surface ligands and exacerbate surface defects. During the synthesis of PbS quantum dots, oleic acid ligands coordinate with Pb atoms on the quantum dot surface through carboxyl groups to form a stable surface passivation layer, which can effectively suppress surface defects. However, the antisolvents (such as acetone) used in existing cleaning processes are highly polar and compete with oleic acid ligands for adsorption, breaking the coordination bonds between oleic acid and the quantum dot surface, causing some oleic acid ligands to fall off and forming surface defect sites with incomplete ligand coverage. These defect sites not only further enhance the adsorption capacity of water and oxygen, but also cause uneven passivation layers during subsequent ligand exchange (such as passivation with iodine ions), making it difficult to form continuous and stable carrier transport channels, further degrading the electrical performance and long-term stability of the detector.
[0026] Figure 1 This is a schematic flowchart of the quantum dot detector fabrication method based on a one-step synthesis method provided in the embodiments of this application, as shown below. Figure 1 As shown, the method for fabricating a quantum dot detector based on a one-step synthesis method includes steps 110, 120, 130, 140, 150, and 160.
[0027] Step 110: Provide a substrate; For example, the substrate is a glass support device with a thickness of 1-2 mm for flatness and a light transmittance of >90%, which can realize infrared and visible light.
[0028] Step 120: Fabricate a bottom electrode on the substrate; In some embodiments, the fabrication of the bottom electrode includes: Sn-doped As a target material; Using a DC power supply as the excitation source, a sputtering gas pressure of 0.3 Pa, and argon as the ionization gas, while reducing the sputtering power to 33 W, the bottom electrode was obtained.
[0029] It is easy to understand that the bottom electrode is fabricated using magnetron sputtering, with the target material being Sn-doped. To achieve higher mobility, a lower sputtering pressure, such as 0.3 ± 0.05 Pa, was used, with argon as the ionization gas and the sputtering power reduced to 33 W. A DC power supply was used as the excitation source to obtain the bottom electrode.
[0030] Step 130: Prepare a hole transport layer on the bottom electrode, wherein the hole transport layer comprises a NiOx thin film and a PbS-EDT thin film; In some embodiments, the preparation of the hole transport layer includes the preparation of a NiOx thin film and a PbS-EDT thin film, wherein the NiOx thin film is prepared by magnetron sputtering, including: Li-doped NiOx was used as the target material; For example, NiO: The ratio is 98.96:1.04wt%. It is easy to understand that during the preparation process, the substrate is placed in a vacuum chamber and evacuated until the base pressure is greater than 1000 kcal / kg. The sputtering pressure was controlled to 3.4 Pa by adjusting the gas flow rate. Argon gas at 100 sccm was introduced as an ionization gas to provide glow discharge. A 200 W radio frequency power supply was used as the excitation source to obtain NiOx thin films.
[0031] In some embodiments, the PbS-EDT thin film preparation includes: PbO was used as the lead source precursor, and PbS CQDs were prepared by thermal implantation of trimethylsilyl sulfide. At this time, the surface of CQDs was coated with oleic acid ligands. After dissolving CQDs, acetone was used as the antisolvent to precipitate CQDs and centrifuge to separate the supernatant from CQDs. The synthesis reaction residue was washed out to obtain CQDs coated with OA. Next, a thin film was prepared by adding OA-coated CQDs at a concentration of 20 mg. Dissolved in n-octane, the solution was spin-coated onto the surface of a NiOx film at 2500 rpm. Then, it was post-treated with a 0.02% (v / v) EDT acetonitrile solution for 30 s to replace the oleic acid ligand with the EDT ligand. Finally, the surface was washed twice with acetonitrile solution. The above operation was repeated twice to obtain the PbS-EDT film.
[0032] Step 140: A quantum dot light-absorbing layer is prepared on the hole transport layer using a one-step synthesis method. The quantum dot light-absorbing layer comprises 1550 nm PbS CQDs. Figure 2 This is a schematic diagram of the one-step synthesis method for preparing quantum dot light-absorbing layers provided in the embodiments of this application, as shown below. Figure 2 As shown, in some embodiments, the fabrication of the quantum dot light-absorbing layer includes PbS quantum dot synthesis, ligand exchange, and the fabrication of a 1550 nm PbSCQDs thin film. The PbS quantum dot synthesis includes: PbS colloidal quantum dots with an absorption peak of 1550 nm were synthesized by thermal injection method to obtain quantum dot stock solution.
[0033] Figure 3 This is a solvent diagram provided in the embodiments of this application, showing the solvent required for the theoretical synthesis of 1g of PbS CQDs, as shown below. Figure 3 As shown, the required solvents include lead oxide (PbO) and lead chloride (PbO). ), octadecene (ODE), oleic acid (OA), hexamethyldisiloxane ( S), with a volume of ml. The specific experimental steps are as follows: Add 268 mg PbO and 41.7 mg PbO to a 100 ml three-necked flask. Then add 10ml ODE and 2ml OA, evacuate and slowly heat to 150℃, during which nitrogen is used to purge more than three times.
[0034] 210μl S was rapidly injected, and after reacting for 2 minutes, the heat source was removed, and 10 ml of n-hexane was added to quench the reaction, yielding the quantum dot stock solution.
[0035] In this embodiment, the absorption wavelength of quantum dots can be changed by adjusting the precursor concentration and reaction temperature, thereby achieving controllable synthesis of quantum dots.
[0036] In some embodiments, the ligand exchange includes: The synthesized quantum dot stock solution was directly mixed with the iodine bromide ligand exchange solution to perform liquid-phase ligand exchange.
[0037] The quantum dot stock solution is an unwashed OA and ODE solution. For example, 1.226 g of lead iodide and 0.424 g of lead bromide are weighed and dissolved in 10 ml of DMF. 10 ml of the quantum dot stock solution is mixed with the exchange solution, shaken for 1 min, and the supernatant is removed. Then, the solution is washed three times with an equal volume of n-octane. After removing the supernatant, the solution is centrifuged at 9000 rpm for 5 min to obtain a black precipitate. The precipitate is then placed in a vacuum chamber and vacuumed to obtain PbS colloidal quantum dots coated with short-chain ligands after exchange.
[0038] In some embodiments, Figure 4 This is a 1550nm PbS CQDs film formation pattern provided in the embodiments of this application, as shown below. Figure 4 As shown, the preparation of the 1550nm PbS CQDs thin film includes: preparing a dispersant with a dispersant ratio of DMF:DMSO:BTA:3-aminopyridine = 350:250:370:30, and preparing a 400mg / ml PbS colloidal quantum dot ink, which is then spin-coated onto the device and annealed at 90℃ for 15min to obtain the 1550nm PbS CQDs thin film.
[0039] For example, the fabrication of the 1550nm PbS colloidal quantum dot infrared detector device adopts the commonly used inverted device structure.
[0040] Step 150: Fabricate an electron transport layer on the quantum dot light-absorbing layer, wherein the electron transport layer comprises C 60 film and film; In some embodiments, the fabrication of the electron transport layer includes Thin film preparation and C 60 Thin film preparation, the The thin film was prepared using atomic layer deposition.
[0041] For example, deposition was performed at 88°C using an ALD process, with the chamber pressure maintained at 0.1 Torr. In each ALD cycle, Tetrakis(dimethylamino)tin (TDMASn) was used as the Sn source. As an oxygen source, TDMASn pulses were applied sequentially for 0.2 s, followed by 5 s purging. A 0.03s pulse followed by a 5s purging process ensures uniform film growth and minimizes impurities.
[0042] In some embodiments, the C 60 The thin film was prepared using a thermal evaporation process.
[0043] For example, C400 with a purity of 99% provided by Xi'an Baolai Chemical Co., Ltd. was used. 60 The precursor is heated to its sublimation temperature using a tungsten boat. During evaporation, to ensure film continuity, the evaporation rate is typically controlled at 0.1 Ås. −1 The typical evaporation current is set to 70A, which can be fine-tuned depending on the performance of the specific evaporation equipment.
[0044] Step 160: Fabricate the top electrode on the electron transport layer.
[0045] Furthermore, the top electrode was coated using a JCP500 magnetron sputtering system with an indium-doped tin oxide target sourced from Zhongnuo New Materials Co., Ltd. The target-substrate distance was set to 80 cm, and DC sputtering was employed. Argon and oxygen were introduced to maintain a chamber pressure of 0.5 Pa, with an argon to oxygen flow rate ratio of 28:0. The sputtering power was set to 100 W, and the sputtering time to 15 min, resulting in a 200 nm thick ITO film as the top electrode.
[0046] The top electrode is transparent and conductive, which can improve infrared transmittance, and the sheet resistance is 100-200Ω.
[0047] It should be noted that, except for the PbS CQDs thin film, all functional thin film layers were prepared using mature and stable vacuum fabrication technology to ensure the overall uniformity, consistency and repeatability of the device. During the fabrication process, process parameters were strictly controlled to ensure the quality of the thin film.
[0048] According to the quantum dot detector fabrication method based on one-step synthesis provided in this application, 1550nm PbS colloidal quantum dots are synthesized using a one-step synthesis method, omitting the quantum dot cleaning step and directly performing liquid-phase exchange. This avoids the introduction of water and oxygen and ligand damage at the source. By eliminating the cleaning step, the contact between residual water in the antisolvent and water vapor and oxygen in the operating environment and the quantum dot surface can be completely avoided, effectively suppressing the chain reaction of surface hydroxylation-hydrogen bond water adsorption-quantum dot epitaxial fusion, and reducing the generation of interband trap states. Combined with direct liquid-phase ligand exchange, a uniform and dense surface passivation layer can be quickly formed, significantly improving carrier mobility and reducing trap state density. Ultimately, this improves the responsivity and detectivity of the infrared detector, and significantly reduces dark current, meeting the requirements of high-sensitivity infrared detection. While simplifying the process, it ensures the stability of the quantum dot surface and improves the performance and large-scale production potential of the infrared detector.
[0049] This application also provides a quantum dot detector based on a one-step synthesis method, such as... Figure 5 As shown, the quantum dot detector based on the one-step synthesis method comprises, from bottom to top, a substrate, a bottom electrode, a hole transport layer, a quantum dot light-absorbing layer, an electron transport layer, and a top electrode. The PbS CQDs photodiode adopts an N-on-P type structure that is more conducive to photocharge collection.
[0050] It should be noted that, in this document, 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 limitations, 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 that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.
[0051] In the description of this application, "first feature" and "second feature" may include one or more of the features.
[0052] In the description of this application, "multiple" means two or more.
[0053] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0055] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A method for fabricating a quantum dot detector based on a one-step synthesis method, characterized in that, include: Provide substrate; A bottom electrode is fabricated on the substrate; A hole transport layer is prepared on the bottom electrode, the hole transport layer comprising a NiOx thin film and a PbS-EDT thin film; A quantum dot light-absorbing layer was prepared on the hole transport layer using a one-step synthesis method. The quantum dot light-absorbing layer comprises 1550 nm PbS CQDs. An electron transport layer is fabricated on a quantum dot light-absorbing layer, the electron transport layer comprising C 60 film and film; A top electrode is fabricated on the electron transport layer.
2. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 1, characterized in that, The fabrication of the bottom electrode includes: Sn-doped As a target material; Using a DC power supply as the excitation source, a sputtering gas pressure of 0.3 Pa, and argon as the ionization gas, while reducing the sputtering power to 33 W, the bottom electrode was obtained.
3. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 2, characterized in that, The hole transport layer is fabricated by NiOx thin film preparation and PbS-EDT thin film preparation. The NiOx thin film preparation is performed by magnetron sputtering, including: Li-doped NiOx was used as the target material; Place the substrate in the vacuum chamber and evacuate until the base pressure is greater than [amount missing]. The sputtering pressure was controlled to 3.4 Pa by adjusting the gas flow rate. Argon gas at 100 sccm was introduced as an ionization gas to provide glow discharge. A 200 W radio frequency power supply was used as the excitation source to obtain NiOx thin films.
4. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 3, characterized in that, The PbS-EDT thin film preparation includes: PbO was used as the lead source precursor, and PbS CQDs were prepared by thermal implantation of trimethylsilyl sulfide to obtain CQDs coated with OA. CQDs coated with OA were administered at a dose of 20 mg. Dissolved in n-octane, the solution was spin-coated onto the surface of a NiOx film at 2500 rpm. Then, it was post-treated with a 0.02% (v / v) EDT acetonitrile solution for 30 s to replace the oleic acid ligand with the EDT ligand. Finally, the surface was washed twice with acetonitrile solution. The above operation was repeated twice to obtain the PbS-EDT film.
5. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 4, characterized in that, The fabrication of the quantum dot light-absorbing layer includes PbS quantum dot synthesis, ligand exchange, and the fabrication of a 1550 nm PbS CQD thin film. The PbS quantum dot synthesis includes: PbS colloidal quantum dots with an absorption peak of 1550 nm were synthesized by thermal injection method to obtain quantum dot stock solution.
6. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 5, characterized in that, The ligand exchange includes: The synthesized quantum dot stock solution was directly mixed with the iodine bromide ligand exchange solution to perform liquid-phase ligand exchange.
7. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 6, characterized in that, The preparation of the 1550nm PbS CQD thin film includes: preparing a dispersant with a dispersant ratio of DMF:DMSO:BTA:3-aminopyridine = 350:250:370:30, and preparing a 400mg / ml PbS colloidal quantum dot ink, which is then spin-coated onto the device and annealed at 90℃ for 15min to obtain the 1550nm PbS CQD thin film.
8. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 7, characterized in that, The fabrication of the electron transport layer includes... Thin film preparation and C 60 Thin film preparation, the The thin film was prepared using atomic layer deposition.
9. The method for fabricating a quantum dot detector based on a one-step synthesis method as described in claim 8, characterized in that, The C 60 The thin film was prepared using a thermal evaporation process.
10. A quantum dot detector based on a one-step synthesis method, characterized in that, The quantum dot detector based on the one-step synthesis method comprises, from bottom to top, a substrate, a bottom electrode, a hole transport layer, a quantum dot light-absorbing layer, an electron transport layer, and a top electrode.