A microfluidic chip for high-temperature synthesis of quantum dots

Abstract

The application discloses a micro-fluidic chip for high-temperature synthesis of quantum dots, which is bonded by a flow channel layer (51) and a whiteboard layer (52). The input area (1), the mixing area (2) and the reaction area (3) are arranged on the flow channel layer (51) and are made of high-temperature-resistant materials. The mixing area (2) receives the reaction precursors from the input area, and the reaction precursors are fully mixed in the main body of the mixing area. The main body of the mixing area further comprises a plurality of continuous protrusions (6) and turns (7). The triangular microstructure (8) is arranged on each protrusion (6) and each turn (7) respectively, so as to realize the full mixing of the reaction precursors in the S-shaped flow channel (4). The fully mixed reaction precursors flow into the reaction area (3), and high-temperature reaction is carried out in the main body of the reaction area, so as to realize the reaction synthesis of the quantum dots. After the reaction, the fluid is output by the reaction area outlet (32). The application can improve the mixing effect of the reaction precursors and effectively improve the reaction synthesis effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the microfluidic technology field, in particular to a microfluidic chip for quantum dot synthesis. BACKGROUND

[0002] Microfluidic technology refers to a technical method for manipulating and controlling small volume fluid through channels with a size of tens of microns to hundreds of microns. The use of microfluidic technology can improve the heat and mass transfer efficiency of reaction precursors, and obtain more high-performance quantum dots. At the same time, microfluidic technology can more accurately regulate reaction parameters, including temperature, flow rate, etc., which helps to realize continuous and consistent quantum dot synthesis, and is an ideal technology for large-scale production.

[0003] Quantum dots are a kind of nanoscale semiconductor materials. Due to its size smaller than the exciton Bohr radius, it has quantum confinement effect and exhibits unique photoelectric properties, such as adjustable emission wavelength, high color purity, high fluorescence quantum efficiency, etc., and has wide application prospects in display, solar cells, optoelectronic devices, etc.

[0004] The introduction of microfluidic technology provides a more accurate reaction control method for the synthesis of quantum dots. Microfluidic chip is the basis for realizing the microfluidic synthesis of quantum materials. However, the widely used microfluidic chip at present is mainly PDMS material (polydimethylsiloxane), which is difficult to withstand high temperature and has many limitations on quantum dot synthesis conditions. SUMMARY

[0005] In order to solve the above problems, the present application provides 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 the mixing zone and the reaction zone.

[0006] The present application utilizes the following technical solutions:

[0007] The microfluidic chip for high-temperature synthesis of quantum dots of the present application is composed of a flow channel layer and a whiteboard layer bonded together; the flow channel layer is provided with an input zone, a mixing zone and a reaction zone composed of high-temperature resistant materials;

[0008] The input zone has an input zone main body, first to third input zone inlets and an input zone outlet, which is used for inputting reaction precursors from the first to third input zone inlets, and the input zone main body further includes a flow channel, which is collected and transported from the input zone outlet to the mixing zone;

[0009] The mixing zone has a mixing zone body, a mixing zone inlet and a mixing zone outlet, is used for receiving reaction precursors from the mixing zone inlet, conveying the reaction precursors to the mixing zone body to mix the reaction precursors sufficiently, and further comprises an S-shaped flow channel, a plurality of protrusions and turns are arranged in the S-shaped flow channel, and triangular microstructures are respectively arranged in the protrusions and the turns.

[0010] The reaction zone has a reaction zone body, a reaction zone inlet and a reaction zone outlet, is used for inputting the reaction precursors mixed sufficiently from the mixing zone outlet into the reaction zone through the reaction zone inlet, performing high-temperature reaction in the reaction zone body to realize reaction synthesis of quantum dots, and outputting the fluid after reaction from the reaction zone outlet, and further comprises a square wave-shaped flow channel.

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

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

[0013] In some embodiments, the reaction zone is connected with a heating plate to perform heating of the reaction zone.

[0014] In some embodiments, the triangular microstructures comprise two shear surfaces and an apex, the apex 83 is directed to a fluid inflow direction, the thickness of the triangular microstructures is consistent with the depth of the S-shaped flow channel.

[0015] In some embodiments, the input zone body is provided with three or more flow channels, and correspondingly has three or more input zone inlets for input of reaction precursors, and the reaction precursors are conveyed from the input zone outlets to the mixing zone after being aggregated.

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

[0017] In some embodiments, the microfluidic chip has a depth of 100 microns, a width of 500 microns, a mixing zone volume of 11.4 microliters, and a reaction zone volume of 10 microliters.

[0018] In some embodiments, the surface of the flow channel layer has two fixed grooves, and the surface of the whiteboard layer has two fixed grooves.

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

[0020] 1) The mixing of the reaction precursors is improved by the design of the triangular microstructures of the mixing zone body.

[0021] 2) The reaction precursors after sufficient mixing realize stable high-temperature reaction in the reaction zone, effectively improve the reaction synthesis effect, and thus synthesize high-performance quantum dots. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a microfluidic chip structure schematic diagram for high-temperature synthesis of quantum dots of the present application;

[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 flow channel structure;

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

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

[0027] REFERENCE NUMERALS:

[0028] 1, input zone, 2, mixing zone, 3, reaction zone, 4, S-shaped flow channel, 51, flow channel layer, 52, whiteboard layer, 6, protruding part, 7, turning part, 8, triangular microstructure, 111, 112, 113, first to third input zone inlets, 14, input zone outlet, 11, input zone inlet, 13, flow channel, 21, mixing zone inlet, 22, mixing zone outlet, 31, reaction zone inlet, 32, reaction zone outlet, 33, square wave-shaped flow channel, 511, 512, 521, 522, fixed groove, 81, 82, shear surface, 83, top angle. DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with the embodiments. The following description of the embodiments is only for the purpose of helping to understand the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0030] As Figures 1 to 3As shown, the microfluidic chip for high-temperature synthesis of quantum dots is bonded by a flow channel layer 51 and a whiteboard layer 52. The flow channel layer 51 is provided with three main regions including an input region 1, a mixing region 2 and a reaction region 3 composed of high-temperature resistant materials. The input region 1 has an input region main body, first to third input region inlets 111, 112 and 113, and an input region outlet 14. The input region main body further includes a flow channel 13 for input from the first to third input region inlets 111, 112 and 113, and the flow channels are collected and delivered to the mixing region 2 from 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 delivering the reaction precursors to the mixing region main body for sufficient mixing of the reaction precursors. A plurality of protrusions 6 and turns 7 are arranged in the S-shaped flow channel 4, and the protrusions 6 and turns 7 serve to flow the reaction precursors 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 reaction precursors mixed sufficiently from the mixing region outlet 22 into the reaction region main body through the reaction region inlet 31, and performing high-temperature reaction in the reaction region main body to realize reaction synthesis of quantum dots, and the reaction fluid is output from the reaction region outlet 32. The reaction region main body further includes a square wave-shaped flow channel 33, which realizes the overall volume requirement of the reaction region in a smaller area through repeated bending of the flow channel, and is beneficial to ensuring the uniformity of the temperature in the reaction region. The reaction fluid is output from the reaction region outlet 32. The mixed reaction precursors are subjected to high-temperature reaction in the reaction region 3 of the microfluidic chip, so as to synthesize quantum dots. The reaction region 3 can be connected to a heating plate for heating, so as to ensure the uniformity and stability of the temperature of the reaction region 3, and realize high-quality synthesis of quantum dots.

[0031] The microfluidic chip for high-temperature synthesis of quantum dots can precisely control the synthesis process of quantum dots by adjusting and optimizing the flow rate of the reaction precursors through the previous injection pump and adjusting the reaction time, and adjusting the temperature of the reaction region through the heating plate.

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

[0033] Specifically, the protruding part 6 and the turning part 7 of the S-shaped flow channel 4 are respectively provided with a triangular microstructure 8, and the shear force and turbulence of the fluid are enhanced through the triangular microstructure 8, so that the turbulence and shear force of the fluid are enhanced to promote the sufficient mixing of the reaction precursors in the mixing area. The sufficient mixing as the optimized mixing effect provides a necessary condition for the efficient synthesis of the subsequent reaction area 3. The triangular microstructure is also made of glass and is fixedly placed in each bend of the mixing area. The triangular microstructure enhances the shear force and turbulence of the fluid, induces chaotic advection, and improves the mixing effect of the reaction precursors in the mixing area.

[0034] As shown in Figure 4 Specifically, the triangular microstructure 8 further includes three shear surfaces 81, 82 and a top corner 83. The top corner 83 faces the fluid inflow direction. The shear surface is the two surfaces constituting the top corner. The thickness of the triangular structure is consistent with the depth of the S-shaped flow channel. The reaction precursors are divided into two parts through the top corner of the triangular microstructure, and the sufficient mixing with better effect is achieved after passing through the triangular microstructure.

[0035] Specifically, the flow channel layer 51 has four fixed grooves 511 and a fixed groove 512, and the whiteboard layer 52 has a fixed groove 521 and a fixed groove 522. When the microfluidic chip is used, the microfluidic chip and the input / output flow channel are fixed by a matching clamp to prevent liquid leakage.

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

[0037] Optionally, more than three flow channels are arranged in the input area 1 of the microfluidic chip, and more than three input area inlets are arranged for input of the reaction precursors. The reaction precursors are collected in the input area main body and transported from the input area outlet 14 to the mixing area 2.

[0038] In the embodiment of the present application:

[0039] The microfluidic chip is made of glass to ensure the high-temperature stability of the chip and clear observation. The synthesis process of quantum dots can be observed more clearly, which is also helpful for spectral characterization and real-time monitoring of the quality of synthesized quantum dots. Glass material has excellent chemical stability, thermal conductivity and light transmission, and can effectively resist high-temperature environment (the maximum temperature resistance is 300 degrees Celsius). In addition, the surface of the glass microfluidic chip is smooth, easy to process and clean.

[0040] The microfluidic chip has a maximum temperature tolerance of 300 DEG C, a depth of 100 mu m, a width of 500 mu m, a mixing area volume of 11.4 mu L, and a reaction area volume of 10 mu L. The size design can provide sufficient reaction time and space to ensure sufficient reaction, and the chip is suitable for various experimental applications.

[0041] The glass microfluidic chip of the application supports efficient mixing of three reaction precursors and reaction at a temperature of not higher than 300 DEG C. By adjusting the 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 perovskite quantum dot reaction synthesis process of the embodiment of the application is as follows:

[0043] S1, the reaction precursors are cesium carbonate (Cs2CO3), lead iodide (PbI2), lead bromide (PbBr2), and organic solvents (such as octadecene ODE) and ligands (such as oleic acid, oleylamine, and ammonium benzenesulfonate), and cesium precursor solution, lead precursor solution and ammonium benzenesulfonate precursor solution are respectively configured;

[0044] S2, the reaction precursors are injected into the inlet of the microfluidic chip through the syringe pump, and the flow rates are respectively set to 10-30 mu L / min, 150-200 mu L / min and 60-90 mu L / min; by adjusting the flow rate, the residence time of the reaction precursors in the chip is controlled, so as to adjust the quality of the synthesized quantum dots;

[0045] S3, the temperature of the reaction area is set to 185 DEG C, and according to different experimental requirements, the temperature can be changed between 150 DEG C and 300 DEG C to optimize the synthesis process of the quantum dots;

[0046] S4, after the reaction precursors are mixed, high-temperature reaction is carried out in the reaction area, the reaction time is set to 4.5 s, and after the reaction is completed, the product flows out through the chip outlet and is collected by a sample bottle;

[0047] S5, the collected quantum dots are centrifuged and purified to obtain perovskite quantum dot solution dissolved in toluene.

[0048] In the above steps, a centrifuge is used to centrifuge at 8000 revolutions per minute, and an appropriate amount of toluene is used for dissolution.

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

[0050] The microfluidic chip can maintain high synthesis stability in continuous operation. The quantum dots synthesized continuously have high fluorescence quantum efficiency and good size uniformity.

[0051] It should be noted that, although the present application has been illustrated and described with reference to certain exemplary embodiments thereof, it is not intended to be limited to the details shown, since various modifications and substitutions can be made without departing from the scope of the present 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 plate layer (52); an input region (1), a mixing region (2) and a reaction region (3) made of a high temperature resistant material are provided in the flow channel layer (51); The input zone (1) has an input zone body, first to third input zone inlets (111), (112), (113) and an input zone outlet (14) for inputting reaction precursors from the first to third input zone inlets (111), (112), (113). The input zone body further includes a flow channel (13), which converges and is transported from the input zone outlet (14) to the mixing zone (2). The mixing zone (2) has a mixing zone body, a mixing zone inlet (21) and a mixing zone outlet (22), which is used to receive the reaction precursor from the mixing zone inlet (21) and transport it to the mixing zone body to fully mix the reaction precursor; the mixing zone body further includes an S-shaped flow channel (4), in which a plurality of continuous protrusions (6) and bends (7) are provided, and triangular microstructures (8) are fixedly provided in the protrusions (6) and the bends (7) respectively, so as to realize the full flow of the reaction precursor in the S-shaped flow channel (4); the triangular microstructure (8) includes two shear surfaces (81) and (82) and a apex (83), the apex (83) facing the fluid inflow direction, and the thickness of the triangular microstructure (8) is consistent with the depth of the S-shaped flow channel; The reaction zone (3) has a reaction zone body, a reaction zone inlet (31) and a reaction zone outlet (32), which is used to input the fully mixed reaction precursor from the mixing zone outlet (22) through the reaction zone inlet (31) and carry out a high-temperature reaction in the reaction zone body to realize the reaction synthesis of quantum dots. After the reaction, the fluid is output from the reaction zone outlet (32). The reaction zone body further includes 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.

3. 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 for heating the reaction zone.

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

5. A microfluidic chip for high-temperature synthesis of quantum dots according to claim 1, characterized in that, This microfluidic chip can withstand temperatures up to 300 degrees Celsius.

6. A 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.

7. A 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 two fixing grooves (511) and (512), and the surface of the whiteboard layer (52) has two fixing grooves (521) and (522).

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