Micro-fluidic chip for high-temperature synthesis of quantum dots

Abstract

The micro-fluidic chip is structurally formed by bonding a runner layer (51) and a white board layer (52), the runner layer (51) is provided with an input area (1), a mixing area (2) and a reaction area (3) which are made of high-temperature-resistant materials, the mixing area (2) receives reaction precursors from the input area and conveys the reaction precursors into a main body of the mixing area to fully mix the reaction precursors, and the white board layer (52) is arranged on the main body of the mixing area. The mixing zone main body further comprises a plurality of continuous protruding parts (6) and turning parts (7), and triangular microstructures (8) are arranged on the protruding parts (6) and the turning parts (7) respectively and used for achieving sufficient mixing of reaction precursors in the S-shaped flow channels (4); fully mixed reaction precursors flow into the reaction zone (3) and are subjected to high-temperature reaction in a main body of the reaction zone to realize reaction synthesis of quantum dots, and the reacted fluid is output from an outlet (32) of the reaction zone. The mixing effect of the reaction precursor can be improved, and the reaction synthesis effect can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, and particularly to a microfluidic chip for quantum dot synthesis. Background Art

[0002] Microfluidic technology refers to a technical method for manipulating and controlling small volumes of fluid through channels with dimensions ranging from dozens of micrometers to hundreds of micrometers. By using microfluidic technology, the heat and mass transfer efficiency of reaction precursors can be improved, and more high-performance quantum dots can be obtained. At the same time, microfluidic technology can more precisely regulate reaction parameters, including temperature, flow rate, etc., which helps to achieve continuous and consistent quantum dot synthesis and is an ideal technology for large-scale production.

[0003] Quantum dots are a type of nanoscale semiconductor material. Due to their size being smaller than the exciton Bohr radius, they exhibit quantum confinement effects and unique optoelectronic properties, such as tunable emission wavelength, high color purity, high fluorescence quantum efficiency, etc., and have broad application prospects in fields such as displays, solar cells, and optoelectronic devices.

[0004] The introduction of microfluidic technology provides a more precise reaction control method for the synthesis of quantum dots, and microfluidic chips are the basis for realizing the microfluidic synthesis of quantum materials. However, the currently widely used microfluidic chips are mainly made of PDMS (polydimethylsiloxane) material, which is difficult to withstand high temperatures and has many limitations on the quantum dot synthesis conditions. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a microfluidic chip for high-temperature synthesis of quantum dots, which improves the mixing effect of reaction precursors and synthesizes high-performance quantum dots through the structural design of a mixing zone and a reaction zone.

[0006] The present invention is realized by the following technical solutions:

[0007] A microfluidic chip for high-temperature synthesis of quantum dots according to the present invention, the structure of the microfluidic chip is bonded by a channel layer 51 and a whiteboard layer 52; the channel layer 51 is provided with an input area 1, a mixing area 2, and a reaction area 3 composed of high-temperature resistant materials;

[0008] The input area 1 has an input area main body, first to third input area inlets 111, 112, 113, and an input area outlet 14, and is used for inputting reaction precursors from the first to third input area inlets 111, 112, 113. The input area main body further includes a channel 13, and the channels 13 converge and are transported from the input area outlet 14 to the mixing area 2;

[0009] The mixing zone 2 has a mixing zone main body, a mixing zone inlet 21 and a mixing zone outlet 22, and is used to receive reaction precursors from the mixing zone inlet 21, convey them to the mixing zone main body to fully mix the reaction precursors. The mixing zone main body further includes an S-shaped flow channel 4. A plurality of continuous protrusions 6 and turning parts 7 are arranged inside the S-shaped flow channel 4, and triangular microstructures 8 are fixedly arranged inside the protrusions 6 and the turning parts 7 respectively, so as to realize the full flow of reaction precursors in the S-shaped flow channel 4;

[0010] The reaction zone 3 has a reaction zone main body, a reaction zone inlet 31 and a reaction zone outlet 32, and is used to input the fully mixed reaction precursors input from the mixing zone outlet 22 through the reaction zone inlet 31, and perform a high-temperature reaction in the reaction zone main body to realize the reaction synthesis of quantum dots. The reacted fluid is output from the reaction zone outlet 32. The reaction zone main body further includes a square-wave-shaped flow channel 33.

[0011] In some embodiments, the flow channel layer 51 and the triangular microstructures are made of glass material.

[0012] In some embodiments, the shear force and turbulence of the fluid are enhanced by the triangular microstructures 8.

[0013] In some embodiments, the reaction zone 3 is connected to a heating plate to heat the reaction zone.

[0014] In some embodiments, the triangular microstructure 8 includes two shear surfaces 81, 82 and a vertex angle 83. The vertex angle 83 faces the fluid inflow direction, and the thickness of the triangular structure 8 is the same as the depth of the S-shaped flow channel.

[0015] In some embodiments, the input zone main body is provided with three or more flow channels, and correspondingly has three or more input zone inlets for inputting reaction precursors. After summarization, they are conveyed from the input zone outlet 14 to the mixing zone 2.

[0016] In some embodiments, the maximum temperature resistance of this microfluidic chip is 300 degrees Celsius.

[0017] In some embodiments, the depth of this microfluidic chip is 100 μm, the width is 500 μm, the volume of the mixing zone is 11.4 μL, and the volume of the reaction zone is 10 μL.

[0018] In some embodiments, the surface of the flow channel layer 51 has fixing grooves 511 and 512, and the surface of the white board layer 52 has fixing grooves 521 and 522.

[0019] Compared with the prior art, the present invention has the following remarkable advantages:

[0020] 1) By designing the triangular microstructures in the main body of the mixing zone, the mixing of reaction precursors is improved;

[0021] 2) The reaction precursors after sufficient mixing achieve a stable high-temperature reaction in the reaction zone, effectively improving the reaction synthesis effect, thereby synthesizing high-performance quantum dots. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of the microfluidic chip for high-temperature synthesis of quantum dots according to the present invention;

[0023] Figure 2 is a side view of the microfluidic chip for high-temperature synthesis of quantum dots;

[0024] Figure 3 is an enlarged view of the S-shaped channel structure;

[0025] Figure 4 is an enlarged view of the triangular microstructures;

[0026] Figure 5 is the fluorescence spectrum diagram of the quantum dots prepared in the embodiment of the present invention;

[0027] Reference Numerals:

[0028] 1. Input area, 2. Mixing zone, 3. Reaction zone, 4. S-shaped channel, 51. Channel layer, 52. White plate layer, 6. Protrusion, 7. Turning part, 8. Triangular microstructures, 111, 112, 113. Inlets of the first to third input areas, 14. Outlet of the input area, 11. Inlet of the input area, 12. Outlet of the input area, 13. Channel, 21. Inlet of the mixing zone, 22. Outlet of the mixing zone, 31. Inlet of the reaction zone, 32. Outlet of the reaction zone, 33. Square wave channel, 511, 512, 521, 522. Fixed grooves, 81, 82. Shearing surfaces, 83. Vertex angle. Detailed Embodiments

[0029] The present invention will be further described below in conjunction with embodiments. The description of the following embodiments is only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0030] As Figures 1 to 3As shown in the figure, the microfluidic chip for high-temperature synthesis of quantum dots in the present invention is formed by bonding a flow channel layer 51 and a white board layer 52. Among them, in the flow channel layer 51, there are three main regions including an input region 1, a mixing region 2, and a reaction region 3, which are made of high-temperature resistant materials. The input region 1 has an input region main body, first to third input region inlets 111, 112, 113, and an input region outlet 14. The input region main body further includes a flow channel 13 for inputting from the first to third input region inlets 111, 112, 113. The flow channels are aggregated and transported to the mixing region 2 through the input region outlet 14. The mixing region 2 has a mixing region main body, a mixing region inlet 21, and a mixing region outlet 22. The mixing region main body further includes an S-shaped flow channel 4 for receiving reaction precursors from the mixing region inlet 21 and transporting them into the mixing region main body to fully mix the reaction precursors; a continuous plurality of protrusions 6 and turning portions 7 are provided in the S-shaped flow channel 4, and the protrusions 6 and turning portions 7 play a role in allowing the reaction precursors to flow fully in the S-shaped flow channel 4. The reaction region 3 has a reaction region main body, a reaction region inlet 31, and a reaction region outlet 32. The reaction region main body further includes a square-wave-shaped flow channel 33 for inputting the fully mixed reaction precursors input from the mixing region outlet (22) through the reaction region inlet (31), performing a high-temperature reaction in the reaction region main body to realize the reaction synthesis of quantum dots, and the fluid after the reaction is output through the reaction region outlet 32. The reaction region main body further includes a square-wave-shaped flow channel 33. Through the repeated bending of the flow channel, the overall volume requirement of the reaction region is achieved in a smaller area, which is beneficial to ensuring the temperature uniformity in the reaction region. The fluid after the reaction is output through the reaction region outlet 32. The mixed reaction precursors perform a high-temperature reaction in the reaction region 3 of the microfluidic chip, thereby synthesizing quantum dots. The reaction region 3 can be connected to a heating plate for heating, which ensures the temperature uniformity and stability of the reaction region 3 and realizes the high-quality synthesis of quantum dots.

[0031] For the microfluidic chip for high-temperature synthesis of quantum dots in the present invention, the flow rate of the reaction precursors is adjusted and optimized through a previous injection pump, and the reaction time is adjusted accordingly. The temperature of the reaction region is adjusted through a heating plate, and the synthesis process of quantum dots can be precisely controlled by using this microfluidic chip. The combination of the triangular micro-structure of the mixing region main body and the temperature control of the reaction region makes the fluorescence quantum efficiency of the synthesized quantum dots higher, the size distribution more uniform, and the synthesis quality improved.

[0032] Specifically, the S-shaped flow channel 4 in the mixing region is used to enhance the turbulence and shear force of the fluid.

[0033] Specifically, triangular microstructures 8 are respectively arranged at the protruding part 6 and the turning part 7 of the S-shaped flow channel 4. By means of the triangular microstructures 8, the shear force and turbulence of the fluid are enhanced, thereby enhancing the turbulence and shear force of the fluid to promote the sufficient mixing of reaction precursors in the mixing zone. Sufficient mixing, as an optimized mixing effect, provides a necessary condition for the efficient synthesis in the subsequent reaction zone 3. The triangular microstructures are also made of glass and are fixedly placed in each bend in the mixing zone. The triangular microstructures are used to enhance the shear force and turbulence of the fluid, trigger chaotic advection, and improve the mixing effect of reaction precursors in the mixing zone.

[0034] As Figure 4 shown, specifically, the triangular microstructure 8 further includes three shear surfaces 81, 82 and a vertex angle 83. Among them, the vertex angle 83 faces the fluid inflow direction. The shear surface is the two surfaces that form the vertex angle. The thickness of the triangular structure is the same as the depth of the S-shaped flow channel. The reaction precursor is split into two parts by the vertex angle of the triangular microstructure, and better sufficient mixing is achieved after passing through the triangular microstructure.

[0035] Specifically, the surface of the flow channel layer 51 has four fixing grooves 511 and fixing grooves 512, and the surface of the whiteboard layer 52 has fixing grooves 521 and fixing grooves 522. When using the microfluidic chip, the microfluidic chip and the input / output flow channels are fixed by a supporting fixture to prevent liquid leakage.

[0036] Optionally, in the embodiments of the present application, the material used to make the microfluidic chip is glass. The high-temperature resistant materials used for the microfluidic chip are such as silicon-based materials, stainless steel, copper or glass, etc., to ensure that the chip can operate stably under high-temperature conditions and guarantee the reliability and consistency of the reaction process.

[0037] Optionally, more than three flow channels are arranged in the input zone 1 of the microfluidic chip, and more than three input zone inlets are provided for inputting reaction precursors. After being summarized by the input zone main body, they are transported from the input zone outlet 14 to the mixing zone 2.

[0038] In the embodiments of the present application:

[0039] The microfluidic chip is made of glass as the raw material to ensure the high-temperature stability and clear observation of the chip, so that the quantum dot synthesis process can be observed more clearly, which is also helpful for its spectral characterization, and then the quality of the synthesized quantum dots can be monitored in real time. The glass material has excellent chemical stability, thermal conductivity and light transmittance, and can effectively resist high-temperature environments (the highest temperature resistance is 300 degrees Celsius). In addition, the surface of the glass microfluidic chip is smooth, which is easy to process and clean.

[0040] The maximum temperature resistance of the microfluidic chip is 300 degrees Celsius. The depth of the microfluidic chip is 100 μm, the width is 500 μm, the volume of the mixing area of the microfluidic chip is 11.4 μL, and the volume of the reaction area of the microfluidic chip is 10 μL. This size design can provide sufficient reaction time and space to ensure the full progress of the reaction, and this chip is suitable for a variety of experimental applications.

[0041] The glass microfluidic chip of the present invention supports the efficient mixing of three reaction precursors and reacts at a temperature not higher than 300 degrees Celsius. By adjusting reaction parameters including flow rate, concentration, temperature, and reaction time, high-performance quantum dots with high fluorescence quantum efficiency and good size distribution uniformity can be obtained.

[0042] The embodiment of the present invention discloses the reaction synthesis process of perovskite quantum dots from reaction precursors as follows:

[0043] S1. The reaction precursors are cesium carbonate (Cs 2 CO 3 ), lead iodide (PbI 2 ), lead bromide (PbBr 2 ), as well as an organic solvent (such as octadecene ODE) and ligands (such as oleic acid, oleylamine, ammonium benzenesulfonate). Cesium precursor solution, lead precursor solution, and ammonium benzenesulfonate precursor solution are respectively prepared.

[0044] S2. The reaction precursors are injected into the feed port of the microfluidic chip by an injection pump, and the flow rates are respectively set to 10 - 30 μL / min, 150 - 200 μL / min, and 60 - 90 μL / min. By adjusting the flow rate, the residence time of the reaction precursors in the chip is controlled, thereby adjusting the quality of the synthesized quantum dots.

[0045] S3. The temperature of the reaction area is set to 185 degrees Celsius. According to different experimental requirements, the temperature can vary between 150 degrees Celsius and 300 degrees Celsius to optimize the synthesis process of quantum dots.

[0046] S4. After the reaction precursors are mixed, they undergo a high-temperature reaction in the reaction area. The reaction time is set to 4.5 s. After the reaction is completed, the product flows out through the chip outlet and is collected with a sampling bottle.

[0047] S5. The collected quantum dots are centrifugally purified to obtain a perovskite quantum dot solution dissolved in toluene.

[0048] In the above steps, centrifugation is performed at 8000 revolutions per minute using a centrifuge and dissolved with an appropriate amount of toluene.

[0049] By adjusting the reaction temperature, reaction precursor concentration, and flow rate to optimize the synthesis conditions of quantum dots, red light quantum dots with a fluorescence quantum efficiency of 85% can be obtained, and the fluorescence spectrum is as Figure 3As shown, the peak wavelength is 627.0 nm, the full width at half maximum is 33.3 nm, and the size distribution has good uniformity.

[0050] During continuous operation, this microfluidic chip can maintain high synthesis stability. The continuously synthesized quantum dots all exhibit high fluorescence quantum efficiency and good size uniformity.

[0051] It should be noted that although the present invention has been shown and described with reference to specific exemplary embodiments of the present invention, those skilled in the art should understand that the present invention is not limited to the above embodiments. Any changes to the present invention fall within the protection scope of the present invention application.

Claims

1. A microfluidic chip for high temperature synthesis of quantum dots, characterized in that: The microfluidic chip structure is formed by bonding a flow channel layer (51) and a white board layer (52); an input area (1), a mixing area (2) and a reaction area (3) made of high temperature resistant materials are arranged on the flow channel layer (51); The input zone (1) comprises an input zone body, first to third input zone inlets (111), (112), (113) and an input zone outlet (14), and is used to input reaction precursors from the first to third input zone inlets (111), (112), (113). The input zone body further comprises a flow channel (13), and the flow channels (13) are combined and transported from the input zone outlet (14) to the mixing zone (2); The mixing zone (2) comprises a mixing zone body, a mixing zone inlet (21) and a mixing zone outlet (22), and is used to receive reaction precursors from the mixing zone inlet (21) and transport them to the mixing zone body to fully mix the reaction precursors; the mixing zone body further comprises an S-shaped flow channel (4), a plurality of continuous protrusions (6) and turning portions (7) are arranged in the S-shaped flow channel (4), and triangular microstructures (8) are fixedly arranged inside the protrusions (6) and the turning portions (7), respectively, so as to enable the reaction precursors to fully flow in the S-shaped flow channel (4); The reaction zone (3) comprises a reaction zone body, a reaction zone inlet (31) and a reaction zone outlet (32), and is used to input the fully mixed reaction precursor input from the mixing zone outlet (22) through the reaction zone inlet (31), and to carry out a high-temperature reaction in the reaction zone body to achieve the reaction synthesis of quantum dots. The post-reaction fluid is output from the reaction zone outlet (32), and the reaction zone body further comprises a square wave flow channel (33).

2. A microfluidic chip for high temperature synthesis of quantum dots according to claim 1, characterized in that: The flow channel layer (51) and the triangular microstructure are made of glass material.

3. A microfluidic chip for high temperature synthesis of quantum dots according to claim 1, characterized in that: The triangular microstructure (8) increases the shear force and turbulence of the fluid.

4. A microfluidic chip for high temperature synthesis of quantum dots according to claim 1, characterized in that: The reaction zone (3) is connected to a heating plate to heat the reaction zone.

5. A microfluidic chip for high temperature synthesis of quantum dots according to claim 1, characterized in that: The triangular microstructure (8) comprises two shear surfaces (81), (82) and a vertex (83), wherein the vertex (83) faces the fluid inflow direction, and the thickness of the triangular structure (8) is consistent with the depth of the S-shaped flow channel.

6. A microfluidic chip for high temperature synthesis of quantum dots according to claim 1, characterized in that: The input zone body is provided with three or more flow channels, and correspondingly has three or more input zone inlets for inputting reaction precursors, which are collected and transported to the mixing zone (2) from the input zone outlet (14).

7. A microfluidic chip for high temperature synthesis of quantum dots according to claim 1, characterized in that: The microfluidic chip can withstand a maximum temperature of 300 degrees Celsius.

8. The microfluidic chip for high-temperature synthesis of quantum dots according to claim 1, characterized in that: The microfluidic chip has a depth of 100 μm, a width of 500 μm, a mixing zone volume of 11.4 μL, and a reaction zone volume of 10 μL.

9. The microfluidic chip for high temperature synthesis of quantum dots according to claim 1, characterized in that: The surface of the flow channel layer (51) has a fixing groove (511) and a fixing groove (512), and the surface of the whiteboard layer (52) has a fixing groove (521) and a fixing groove (522).

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