Quantum dot laminated bias voltage regulation spectrum device preparation method and product

Abstract

The invention discloses a quantum dot laminated bias voltage regulation spectrum device preparation method and a product, which can improve the response sensitivity and response speed of an infrared detector under multiple bands, reduce the preparation cost, and realize that depletion regions are formed in different quantum dot layers through bias voltage regulation, thereby selectively exciting to generate light current, reducing signal cross interference and improving the spectrum detection efficiency. And the overall electrical performance and the environmental stability of the device are optimized to meet the actual application requirements. The method comprises the following steps: (1) preparing a quantum dot solution; (2) spin-coating quantum dots with different wave bands on the substrate layer by layer, and then evaporating Au on the top layer to serve as an extraction electrode;

Description

Technical Field

[0001] The present invention relates to the field of infrared spectroscopy detection devices, and particularly to a preparation method of a quantum dot stacked layer bias voltage regulated spectroscopy device, and a quantum dot stacked layer bias voltage regulated spectroscopy device manufactured by using this preparation method of the quantum dot stacked layer bias voltage regulated spectroscopy device. Background Art

[0002] Although traditional infrared detection devices such as HgCdTe have advantages in performance, their preparation processes are complex and the costs are relatively high; while quantum dot infrared detection devices prepared based on solution processes are not only simple in process but also convenient for large-scale preparation at low cost.

[0003] For example, Imran et al. proposed that by a halogen-driven synthesis method, the size of InSb colloidal quantum dots can be regulated, and then a short-wave infrared photodetector can be prepared. In recent years, quantum dot infrared detection technology has been developing towards high sensitivity and low noise, but there are still great defects in quantum dot synthesis, interlayer interface control and bias voltage regulation. Summary of the Invention

[0004] To overcome the defects of the prior art, the technical problem to be solved by the present invention is to provide a programmable photodetector, which can improve the response sensitivity and response speed of an infrared detector in multiple bands, reduce the preparation cost at the same time, and realize the formation of depletion regions in different quantum dot layers through bias voltage regulation, so as to selectively excite and generate photocurrent, reduce signal cross-interference, optimize the overall electrical properties and environmental stability of the device to meet the actual application requirements.

[0005] The technical solution of the present invention is: a preparation method of a quantum dot stacked layer bias voltage regulated spectroscopy device, which includes the following steps:

[0006] (1) Prepare a quantum dot solution;

[0007] (2) Spin-coat quantum dots of different bands layer by layer on a substrate, and then evaporate Au on the top layer as an extraction electrode;

[0008] The step (1) includes the following sub-steps:

[0009] (1.1) Prepare chemical reagents and solvents required for preparing quantum dots, including: trioctylphosphine, tellurium, mercury chloride, oleylamine, dodecyl mercaptan, tetrachloroethylene, didodecyldimethylammonium bromide, chlorobenzene, gold, silver telluride, (3-mercaptopropyl)trimethoxysilane, 1,2-ethanedithiol, hydrochloric acid, isopropanol, methanol;

[0010] (1.2) In a nitrogen glove box, take 1.276 g of tellurium and dissolve it in 10 ml of trioctylphosphine solution. Under the condition of 100 °C, add a magnetic stirrer and stir to dissolve overnight. After filtration, a bright yellow trioctylphosphine telluride solution is obtained;

[0011] (1.3) Take 1.2 ml of trioctylphosphine, 3.6 ml of dodecanethiol, and 16 ml of tetrachloroethylene. After mixing, a quenching solution is obtained and stored in a refrigerator.

[0012] (1.4) Using oleylamine as a solvent, dissolve 108 mg of mercury chloride in 16 ml of oleylamine at 105 °C

[0013] with stirring for 1 hour to form a pale yellow transparent precursor solution. After the solution becomes clear, lower the temperature and wait for it to stabilize. Then add 400 μl of TOPTe solution. After reacting for a preset time, add the quenching solution to stop the reaction.

[0014] (1.5) For the solution obtained in step (1.4), divide it into three equal parts and add 2 ml of didodecyldimethylammonium bromide to each part. Then add isopropanol solution to make up to 50 ml. After centrifugation, dissolve the quantum dots on the cup wall with 2 ml of chlorobenzene solution respectively. Then add 2 ml of didodecyldimethylammonium bromide again and add isopropanol solution to make up to 50 ml. After centrifugation, dissolve the quantum dots on the cup wall with 2 ml of chlorobenzene solution respectively. Then add 2 ml of didodecyldimethylammonium bromide again and add isopropanol solution to make up to 50 ml. After centrifugation, dissolve the quantum dots on the three cup walls with 2 ml of chlorobenzene solution to obtain the quantum dot solution for spin coating.

[0015] Also provided is a product prepared by the method for preparing a quantum dot stacked bias voltage modulation spectroscopy device.

[0016] The beneficial technical effects of the present invention are as follows:

[0017] 1. Improve the response sensitivity and response speed of the infrared detector in multiple bands, and at the same time reduce the preparation cost.

[0018] 2. Achieve the formation of depletion regions in different quantum dot layers through bias voltage modulation, thereby selectively exciting the generation of photocurrent and reducing signal cross-interference.

[0019] 3. Optimize the overall electrical performance and environmental stability of the device to meet the actual application requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a product prepared by the method for preparing a quantum dot stacked bias voltage modulation spectroscopy device according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solution in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] It should be noted that the term "including" and any variations thereof in the specification and claims of the present invention and the above-mentioned accompanying drawings are intended to cover non-exclusive inclusion. For example, a process, method, device, product or equipment including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or equipment.

[0023] First, the abbreviations and meanings of the present invention are described.

[0024] TOP: Trioctylphosphine, an organic reagent used to prepare TOPTe solution.

[0025] Te: Tellurium, used for synthesizing mercury telluride.

[0026] HgCl2: Mercuric chloride, a mercury source.

[0027] OLA: Oleylamine, a quantum dot ligand.

[0028] DDT: Dodecanethiol, used as an organic ligand during the synthesis of quantum dots.

[0029] TCE: Tetrachloroethylene, an organic solvent.

[0030] DDAB: Didodecyldimethylammonium bromide, a stabilizer in the quantum dot dispersion.

[0031] CB: Chlorobenzene, used as a quantum dot solvent.

[0032] Au: Gold, a top electrode material.

[0033] Ag2Te: Silver telluride, used for quantum dot doping.

[0034] MPTS: (3-Mercaptopropyl)-Trimethoxysilane, used for surface functionalization of the substrate.

[0035] EDT: 1,2-Ethanedithiol, used for ligand exchange.

[0036] HCl: Hydrochloric acid, preventing Hg 2+ from being oxidized.

[0037] IPA: Isopropyl alcohol, used for solution dilution and cleaning.

[0038] MeOH: Methanol, used for dissolving mercury chloride.

[0039] ITO: Indium tin oxide, a commonly used transparent conductive thin film material.

[0040] A method for preparing a quantum dot stacked layer bias-regulated spectroscopy device, comprising the following steps:

[0041] (1) Prepare a quantum dot solution;

[0042] (2) Spin-coat quantum dots of different wavelength bands layer by layer on a substrate, and then evaporate Au on the top layer as an extraction electrode;

[0043] The step (1) includes the following sub-steps:

[0044] (1.1) Prepare the chemical reagents and solvents required for preparing quantum dots, including: trioctylphosphine, tellurium, mercury chloride, oleylamine, dodecanethiol, tetrachloroethylene, didodecyldimethylammonium bromide, chlorobenzene, gold, silver telluride, (3-mercaptopropyl)trimethoxysilane, 1,2-ethanedithiol, hydrochloric acid, isopropyl alcohol, methanol;

[0045] (1.2) In a nitrogen glove box, dissolve 1.276 g of tellurium in 10 ml of trioctylphosphine solution, add a magnetic stirrer and stir to dissolve overnight at 100 °C, and obtain a bright yellow trioctylphosphine telluride solution after filtration;

[0046] (1.3) Take 1.2 ml of trioctylphosphine, 3.6 ml of dodecanethiol and 16 ml of tetrachloroethylene, mix them to obtain a quenching solution, and store it in a refrigerator;

[0047] (1.4) Using oleylamine as a solvent, dissolve 108 mg of mercury chloride and 16 ml of oleylamine at 105 °C

[0048] stir for 1 hour to form a pale yellow transparent precursor solution. After the solution becomes clear, lower the temperature and wait for stabilization, add 400 μl of TOPTe solution, and add the quenching solution to stop the reaction after the preset reaction time;

[0049] (1.5) The solution obtained in step (1.4) is evenly divided into three portions, and 2 ml of didodecyldimethylammonium bromide is added to each portion. Then, isopropanol solution is added to make up to 50 ml. After centrifugation, 2 ml of chlorobenzene solution is used to dissolve the quantum dots on the cup wall respectively. Then, 2 ml of didodecyldimethylammonium bromide is added again to each portion, and isopropanol solution is added to make up to 50 ml. After centrifugation, 2 ml of chlorobenzene solution is used to dissolve the quantum dots on the cup wall respectively. Then, 2 ml of didodecyldimethylammonium bromide is added again to each portion, and isopropanol solution is added to make up to 50 ml. After centrifugation, 2 ml of chlorobenzene solution is used to dissolve the quantum dots on the three cup walls to obtain the quantum dot solution for spin coating.

[0050] The beneficial technical effects of the present invention are as follows:

[0051] 1. Improve the response sensitivity and response speed of the infrared detector in multiple bands, and at the same time reduce the preparation cost.

[0052] 2. Realize the formation of depletion regions in different quantum dot layers through bias voltage regulation, so as to selectively excite and generate photocurrent and reduce signal cross-interference.

[0053] 3. Optimize the overall electrical performance and environmental stability of the device to meet the actual application requirements.

[0054] Preferably, in step (1), the reaction temperature for synthesizing 1.85 μm quantum dots is 60 °C, and the reaction time is 5 min.

[0055] Preferably, in step (1), the reaction temperature for synthesizing 2.43 μm quantum dots is 80 °C, and the reaction time is 4 min.

[0056] Preferably, in step (1), the reaction temperature for synthesizing 3.26 μm quantum dots is 90 °C, and the reaction time is 6 min.

[0057] Preferably, in step (1), the reaction temperature for synthesizing 3.86 μm quantum dots is 100 °C, and the reaction time is 10 min.

[0058] Preferably, in step (1), the reaction temperature for synthesizing 4.43 μm quantum dots is 105 °C, and the reaction time is 20 min.

[0059] Preferably, in step (2), a commercial ITO-coated sapphire Al2O3 substrate is used, the substrate size is 15 mm × 15 mm × 1 mm, the ITO size is 15 mm × 5 mm, and the thickness is 135 nm.

[0060] Preferably, in the step (2), the cleaning steps of the substrate before use are as follows: wipe the surface of the substrate with a dust-free cloth and dishwashing liquid until it is in a flowing state, and then place it on a wafer holder; place the wafer holder in ultrapure water and clean it with an ultrasonic cleaner for ten minutes, replace the ultrapure water, and repeat twice; place the wafer holder in alcohol and clean it with an ultrasonic cleaner for ten minutes, replace the alcohol, and repeat twice; after cleaning, the substrate is stored in alcohol, and the surface droplets are blown dry with nitrogen before use.

[0061] Preferably, in the step (2), on the cleaned substrate, it is treated with (3-mercaptopropyl) trimethoxysilane for a preset time, then rinsed with IPA and blown dry; quantum dots of different wavelengths are spin-coated layer by layer. After each layer of quantum dots forms a film, it is successively treated with a methanol solution of 15% concentration of mercury chloride and a hydrochloric acid / 1,2-ethanedithiol / isopropanol solution with a volume ratio of 1:1:200. The surface solution is rinsed off with an isopropanol solution respectively, and finally the surface solution is blown off with an air gun; after the last layer of quantum dots is treated, it is doped with a methanol solution of 15% concentration of mercury chloride of silver telluride solution, and after the treatment is completed, it is rinsed off with an isopropanol solution and spin-dried.

[0062] As Figure 1 shown, a product prepared by the method for preparing a quantum dot stacked bias voltage modulation spectrum device according to the present invention is also provided.

[0063] The embodiments of the present invention are described in detail below.

[0064] Device preparation is carried out according to the above method. The ITO-coated sapphire substrate, after the cleaning step, is placed at the nozzle of the spin coater and waits for spin coating.

[0065] The substrate is treated with MPTS for 40 s, then rinsed with IPA, and then blown dry with an air gun. Take a chlorobenzene solution of quantum dots with an absorption band of 4.43 μm, and suck 60 μl with a pipette gun and drop it at the center of the substrate. The spin coating parameters are 1000 r / min for 10 s and 3000 r / min for 10 s. Then suck an appropriate amount of IPA solution of 15% concentration of HgCl2 with a pipette and cover it on the substrate. After treatment for 10 s, it is rinsed with IPA solution, and then the excess liquid is blown away with an air gun. Then cover the HCl / EDT / IPA solution with a volume ratio of 1:1:200 on the substrate. After treatment for 10 s, it is rinsed with IPA solution, and then the excess liquid is blown away with an air gun. Repeat this four times to complete the spin coating of a quantum dot layer with an absorption band of 4.43 μm. Replace the quantum dot solution and complete the above steps in order from large to small wavelength band to complete the spin coating of the quantum dot layer.

[0066] Take an appropriate amount of Ag2Te solution, cover it on the substrate, and perform spin coating. Take an appropriate amount of a 15% concentration of HgCl2 in MeOH solution, cover it on the substrate, and after treating for 10 s, perform spin drying. Take an appropriate amount of IPA solution, cover it on the substrate, and after treating for 10 s, perform spin drying. The spin coating parameters are all 3000 r / min for 10 s.

[0067] Using the vacuum thermal evaporation method, deposit an Au electrode with a size of 15 mm × 5 mm and a thickness of 50 nm on the top layer. The Au electrode is perpendicular to the bottom ITO, forming an overlapping area with an effective area of 5 mm × 5 mm.

[0068] The device fabrication is completed.

[0069] Device testing part: Lead out the ITO electrode and the Au electrode of the device respectively, and convert the current signal into a voltage signal through a transimpedance amplifier. After fixing the device, place it in front of the light source of a Fourier transform infrared spectrometer (wavenumber range: 7000 cm -1 ~500 cm -1 ). Record the response spectra of the device under different reverse biases.

[0070] In addition to the above embodiments, the present invention can also adopt the following alternative solutions:

[0071] 1. Quantum dot material substitution: In addition to Hg-based quantum dots, semiconductor quantum dots such as CdSe and PbS can be selected. Their synthesis methods are similar, but the reaction temperature and time need to be adjusted.

[0072] 2. Solvent system replacement: In addition to chlorobenzene and tetrachloroethylene, other organic solvents such as toluene or xylene can be selected as long as the quantum dots are evenly dispersed in the solution.

[0073] 3. Electrode preparation process: In addition to the thermal evaporation method, the Au electrode can be prepared by magnetron sputtering or electrochemical deposition methods, and their final effects are similar.

[0074] 4. Substrate surface treatment: In addition to MPTS, other silane coupling agents such as aminopropyltriethoxysilane can also be selected, and their adhesion effects and stabilities are verified by experiments.

[0075] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. Preparation method of quantum dot stacked layer bias voltage regulated spectrum device, characterized in that: It includes the following steps: (1) Prepare a quantum dot solution; (2) Spin-coat quantum dots of different wavelength bands layer by layer on a substrate, and then evaporate Au on the top layer as a lead-out electrode; The step (1) includes the following sub-steps: (1.1) Prepare the chemical reagents and solvents required for preparing quantum dots, including: trioctylphosphine, tellurium, mercury chloride, oleylamine, dodecanethiol, tetrachloroethylene, didodecyldimethylammonium bromide, chlorobenzene, gold, silver telluride, (3-mercaptopropyl)trimethoxysilane, 1,2-ethanedithiol, hydrochloric acid, isopropanol, methanol; (1.2) In a nitrogen glove box, dissolve 1.276 g of tellurium in 10 ml of trioctylphosphine solution, add a magnetic stirrer and stir to dissolve overnight at 100 °C, and obtain a bright yellow trioctylphosphine telluride solution after filtration; (1.3) Take 1.2 ml of trioctylphosphine, 3.6 ml of dodecanethiol and 16 ml of tetrachloroethylene, mix them to obtain a quenching solution, and store it in a refrigerator; (1.4) Using oleylamine as a solvent, stir and dissolve 108 mg of mercury chloride and 16 ml of oleylamine at 105 °C for 1 hour to form a light yellow transparent precursor solution. After the solution becomes clear, lower the temperature and wait for it to stabilize, add 400 μl of TOPTe solution, and add the quenching solution to stop the reaction after a preset reaction time; (1.5) Divide the solution obtained in step (1.4) into three equal parts, add 2 ml of didodecyldimethylammonium bromide to each part, and then add isopropanol solution to make up to 50 ml; after centrifugation, dissolve the quantum dots on the cup wall with 2 ml of chlorobenzene solution respectively, add 2 ml of didodecyldimethylammonium bromide again, and then add isopropanol solution to make up to 50 ml; after centrifugation, dissolve the quantum dots on the cup wall with 2 ml of chlorobenzene solution respectively, add 2 ml of didodecyldimethylammonium bromide again, and then add isopropanol solution to make up to 50 ml. After centrifugation, dissolve the quantum dots on the three cup walls with 2 ml of chlorobenzene solution to obtain the quantum dot solution for spin coating.

2. The method for preparing a quantum dot stacked bias voltage regulated spectral device according to claim 1, wherein: In the step (1), the reaction temperature for synthesizing 1.85 μm quantum dots is 60 °C, and the reaction time is 5 min.

3. The method for preparing a quantum dot stacked bias voltage regulated spectral device according to claim 1, characterized in that: In the step (1), the reaction temperature for synthesizing 2.43 μm quantum dots is 80 °C, and the reaction time is 4 min.

4. The method for preparing a quantum dot stacked bias voltage regulated spectral device according to claim 1, wherein: In the step (1), the reaction temperature for synthesizing 3.26 μm quantum dots is 90 °C, and the reaction time is 6 min.

5. The method for preparing a quantum dot stacked bias voltage regulated spectroscopic device according to claim 1, wherein: In the step (1), the reaction temperature for synthesizing 3.86 μm quantum dots is 100 °C, and the reaction time is 10 min.

6. The method for preparing a quantum dot stacked bias voltage regulated spectroscopic device according to claim 1, wherein: In the step (1), the reaction temperature for synthesizing 4.43 μm quantum dots is 105 °C, and the reaction time is 20 min.

7. The method for preparing a quantum dot stacked bias voltage regulated spectral device according to claim 1, wherein: In the step (2), use a commercial ITO-coated sapphire Al2O3 substrate with a substrate size of 15 mm × 15 mm × 1 mm, an ITO size of 15 mm × 5 mm, and a thickness of 135 nm.

8. The method for preparing a quantum dot stacked bias voltage regulated spectroscopic device according to any one of claims 1-7, characterized in that: In step (2), the cleaning steps of the substrate before use are as follows: wipe the surface of the substrate with a dust-free cloth and dishwashing liquid until it is in a running water state, and then place it on a wafer holder; place the wafer holder in ultrapure water and clean it with an ultrasonic cleaner for ten minutes, change the ultrapure water, and repeat twice; place the wafer holder in alcohol and clean it with an ultrasonic cleaner for ten minutes, change the alcohol, and repeat twice; after cleaning, the substrate is stored in alcohol, and the surface droplets are blown dry with nitrogen before use.

9. The method for preparing a quantum dot stacked bias voltage regulated spectroscopic device according to claim 8, wherein: In step (2), on the cleaned substrate, it is treated with (3-mercaptopropyl) trimethoxysilane for a preset time, and after that, it is rinsed with IPA and blown dry; different wavelength bands of quantum dots are spin-coated layer by layer. After each layer of quantum dots forms a film, it is successively treated with a methanol solution of 15% mercury chloride and a hydrochloric acid / 1,2-ethanedithiol / isopropanol solution with a volume ratio of 1:1:

200. The surface solution is rinsed off with an isopropanol solution respectively, and finally the surface solution is blown off with an air gun; after the treatment of the last layer of quantum dots is completed, doping treatment is carried out with a silver telluride solution and a methanol solution of 15% mercury chloride. After the treatment is completed, it is rinsed off with an isopropanol solution and spin-dried.

10. A product prepared by the method for preparing a quantum dot stacked bias voltage modulation spectroscopic device according to claim 9.

Images