A multispectral detector and a method of manufacturing the same

Abstract

The application discloses a kind of multispectral detectors and preparation method thereof, belong to multispectral detector technical field.Method includes: S1, electrode and channel are prepared on substrate;S2, anti-solvent is added to one channel of single nozzle multi-channel nozzle, different perovskite solution is added to other channels;S3, the ink proportion of each channel is adjusted according to the proportion of required halogen element, and the ink of each channel flows is pre-mixed at Taylor cone and then deposited in specified channel;S4, repeat step S3 until all channels are deposited by ink, thereby obtaining multispectral detector with different spectral absorption characteristics.So, the resolution of multispectral detector obtained by the application can reach sub-micron level, and after being prepared into single crystal, it has more excellent performance, and can be accurately positioned, control spectral range, low cost, can realize miniaturization, flexibility and integration.

Description

Technical Field

[0001] This invention belongs to the field of multispectral detector technology, and more specifically, relates to a multispectral detector and its fabrication method. Background Technology

[0002] A multispectral detector is a device that detects and measures the properties of light through the photoelectric effect, typically manifested as a photocurrent. Today, the photoelectric conversion in multispectral detectors has attracted increasing attention from academia and industry in a wide range of applications, including image sensing, optical communication, environmental monitoring, and chemical / biological detection.

[0003] For multispectral detection requiring wide spectral range identification, it is generally necessary to configure multiple functional materials with different spectral absorption capabilities. Current optoelectronic imaging device manufacturing mainly relies on polycrystalline thin film processing technologies such as spin coating, vapor phase growth, and blade coating. These processes are complex, require the configuration of multiple functional materials, and are cumbersome to operate, making them unsuitable for manufacturing arrays with precise positioning, size, and shape requirements. Furthermore, the preparation of polycrystalline thin films heavily depends on quenching processes to achieve high nucleation density, which sacrifices grain size, crystal structure, crystallinity, and trap density. Summary of the Invention

[0004] To address the shortcomings and improvement needs of existing technologies, this invention provides a multispectral detector and its fabrication method. By employing a single-nozzle multi-channel nozzle, the solution can be premixed at the Taylor cone, requiring only one spray to obtain the desired solution. This overcomes the cumbersome operation caused by the need to configure multiple spectral absorption functional materials in existing fabrication methods. Furthermore, by adding antisolvents to the channels to generate single crystals with different spectral absorption characteristics, this invention overcomes the problem of sacrificing grain size, crystal structure, crystallinity, and trap density when fabricating polycrystalline thin films.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a method for fabricating a multispectral detector, comprising the following steps:

[0006] S1, Electrodes and channels are fabricated on the substrate;

[0007] S2, add an antisolvent to one channel of a single-nozzle multi-channel nozzle, and add different perovskite solutions to the other channels;

[0008] S3, adjust the ink output ratio of each channel according to the required halogen element ratio, and premix the ink flowing out of each channel at the Taylor cone before depositing it in the designated channel;

[0009] S4. Repeat step S3 until all channels are coated with ink, thus obtaining a multispectral detector with different spectral absorption characteristics.

[0010] Furthermore, in S2, the single-nozzle multi-channel nozzle is prepared in the following manner:

[0011] One end of the multi-channel capillary is drawn into a single-nozzle multi-channel nozzle using a microelectrode drawing instrument; and multiple copper wires are inserted into the other end of the multi-channel capillary to supply power to the solution added to each channel.

[0012] Furthermore, the printing method of the single-nozzle multi-channel printhead is hybrid electrohydrodynamic printing, and the material is an insulating material.

[0013] Furthermore, in step S3, adjusting the ink output ratio of each channel according to the required halogen element ratio includes:

[0014] If each channel of a single-nozzle multi-channel printhead is connected to a controllable voltage source, the ink output ratio of each channel can be adjusted by regulating the voltage waveform so that the mixed ink droplets meet the required halogen element ratio.

[0015] If each channel of a single-nozzle multi-channel printhead is connected to a precision flow pump, the ink output ratio of each channel can be adjusted by regulating the air pressure, so that the mixed ink droplets meet the required halogen element ratio.

[0016] Furthermore, in S3, the ink flowing out of each channel is premixed at the Taylor cone and then deposited in the designated channel, forming a single crystal after a period of time;

[0017] The proportion of ink flowing out of each channel before premixing will affect the detection range of the spectrum, and the size of the ink droplets after premixing will affect the size of the single crystal.

[0018] Furthermore, the radius of the single crystal is 10nm-500μm, and the spectral range of the detection is 300nm-800nm.

[0019] Further, in S1, the substrate is a silicon wafer substrate, a silicon dioxide substrate, a glass substrate, an ITO glass substrate, a PDMS substrate, or any of the above substrates that have undergone hydrophobic treatment.

[0020] Further, in S2, the antisolvent is any one or a mixture of several materials, including ethanol, isopropanol, butanol, ethyl acetate, chloroform, chlorobenzene, butyl acetate, dichlorobenzene, anisole, trifluorotoluene, diethyl ether, m-xylene, toluene, mesitylene, and N-cyclohexylpyrrolidone.

[0021] Further, in S2, the solvent of the perovskite solution is any one or a mixture of several materials selected from dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, N,N-dimethylacetamide, acetonitrile, tetramethylsilane, polycarbonate, N-methylpyrrolidone, dimethylacetamide, N,N-dimethylpropenylurea, methylammonium acetate, methylammonium formate, and butylammonium acetate.

[0022] Secondly, the present invention provides a multispectral detector, which is prepared by the method for preparing a multispectral detector described in the first aspect.

[0023] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0024] (1) This invention utilizes a single-nozzle multi-channel nozzle to premix different perovskite solutions and antisolvents in a Taylor cone, requiring only one spray to obtain ink droplets with the desired halogen element ratio. These ink droplets are then deposited in designated channels to obtain a patterned array of various halogen element ratios. This enables the rapid fabrication of multiple materials with different spectral detection ranges, and the fabricated multispectral detectors can achieve sub-micron resolution, precise positioning, and spectral range control. Furthermore, it is low-cost and allows for miniaturization, flexibility, and integration.

[0025] (2) This invention employs electrohydrocarbon printing, which enables precise positioning and high-resolution deposition of droplets. The fabricated array can be integrated with a chip, and by controlling the size of the deposited droplets, submicron-sized single crystals can be obtained. This improves performance and facilitates miniaturization, making it suitable for further applications in micro-devices and portable devices.

[0026] (3) The present invention can be fabricated on a variety of substrates, including flexible substrates and curved substrates, and therefore can be used for flexible wearable devices with good accuracy and flexibility. Attached Figure Description

[0027] Figure 1 This is a schematic flowchart of the fabrication method of the multispectral detector provided by the present invention;

[0028] Figure 2 This is a schematic diagram of the single-nozzle multi-channel nozzle structure provided by the present invention;

[0029] Figure 3 This is a flowchart illustrating the process of adjusting the ink output ratio of each channel provided by the present invention.

[0030] Figure 4 This is a schematic diagram of single crystal growth provided by the present invention;

[0031] Figure 5This is a schematic diagram of the single-nozzle multi-channel hybrid printing system provided by the present invention;

[0032] Figure 6 This is an exploded view of the submicron-scale single-crystal multispectral detector obtained by this invention;

[0033] Figure 7 This is a schematic diagram of single-crystal arrays with different spectral detection ranges obtained by the present invention;

[0034] Figure 8 These are schematic diagrams of single-crystal arrays of different sizes and shapes obtained by the present invention;

[0035] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-single-nozzle multi-channel nozzle, 2-controllable voltage source, 3-precision flow meter, 4-movable substrate, 5-computer, 6-substrate, 7-integrated circuit, 8-single crystal array. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0037] In this invention, the terms "first," "second," etc. (if present) in the invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0038] See Figure 1 , combined Figures 2 to 5 The present invention provides a method for fabricating a multispectral detector, the method comprising operations S1 to S4.

[0039] Operation S1 is used to fabricate electrodes and channels on the substrate.

[0040] In this embodiment, specifically, the substrate is first cleaned, and photoresist is spin-coated onto the cleaned substrate and cured on a hot plate; then, it is exposed and developed using a photolithography machine; finally, a layer of conductive electrodes is magnetron sputtered onto the substrate, and excess electrodes are removed in acetone. The substrate is preferably a silicon wafer substrate, a silicon dioxide substrate, a glass substrate, an ITO glass substrate, a PDMS substrate, or any of the above substrates that have undergone hydrophobic treatment.

[0041] Operate S2 to add an antisolvent to one channel of the single-nozzle multi-channel nozzle, and add different perovskite solutions to the other channels.

[0042] In this embodiment, the printing method used is hybrid electrohydrodynamic printing, which can be expanded to include thermal printing, piezoelectric printing, inkjet printing, screen printing, spray printing, etc.; the printhead used is preferably a metal printhead, a gold-plated glass printhead, a glass filament printhead, a dispensing printhead, etc.; the printhead structure is preferably a four-channel structure with a single nozzle, such as... Figure 2 As shown, it can also be expanded into a multi-channel structure with a single nozzle. During the printing process, the substrate can move freely in the XY plane, and the nozzle can move up and down in the Z-axis direction to adjust the distance between the nozzle and the substrate.

[0043] Materials with different spectral absorption characteristics are preferably one or a mixture of quantum dots or perovskites; the solvent for the perovskite solution is preferably one or a mixture of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), γ-butyrolactone (GBL), N,N-dimethylacetamide (MDA), acetonitrile (ACN), tetramethylsilane (TMS), polycarbonate (PC), N-methylpyrrolidone (NMP), dimethylacetamide (DMAC), N,N-dimethylpropenylurea (DMPU), methylammonium acetate (MAAc), methylammonium formate (MAFa), and butylammonium acetate (BAAc); the antisolvent is preferably one or a mixture of ethanol, isopropanol, butanol, ethyl acetate, chloroform, chlorobenzene, butyl acetate, dichlorobenzene, anisole, trifluorotoluene, diethyl ether, m-xylene, toluene, mesitylene, and n-cyclohexyl-2-pyrrolidone (CHP).

[0044] Operate S3 to adjust the ink output ratio of each channel according to the required halogen element ratio, and premix the ink flowing out of each channel at the Taylor cone before depositing it in the designated channel.

[0045] In this embodiment, as Figure 3 As shown, if each channel of a single-nozzle multi-channel printhead is connected to a controllable voltage source, the ink output ratio of each channel can be adjusted by regulating the voltage waveform so that the mixed ink droplets meet the required halogen element ratio; if each channel of a single-nozzle multi-channel printhead is connected to a precision flow pump, the ink output ratio of each channel can be adjusted by regulating the air pressure so that the mixed ink droplets meet the required halogen element ratio.

[0046] Color recognition can be achieved by adjusting the ratio of halogen atoms to change the band gap and achieve different band-edge absorptions. This can be done by altering the voltage waveform of each channel. Generally, increasing the amplitude and bias of the applied voltage, increasing the duty cycle of the square wave, and decreasing the frequency of the square wave can all increase the ink output ratio of the solution. Simultaneously, during electro-inking, air pressure can be applied to each channel to further regulate the ink output ratio; increasing the air pressure increases the ink output ratio of that channel.

[0047] Regarding solution mixing, because a single nozzle is used, the solution is premixed at the Taylor cone formed during spraying and further mixed at the deposition site. Subsequent processing at the deposition site can accelerate the mixing process and promote homogeneity, such as altering the wettability of the substrate at the deposition site, applying ultrasound at the deposition site, or applying an electric field to promote electrowetting.

[0048] After obtaining the perovskite mixed solution, the solution grows into single crystals under the action of an antisolvent, such as... Figure 4 As shown, the single crystal growth process is illustrated from left to right. The proportion of ink flowing out of each channel before premixing affects the spectral detection range, while the size of the ink droplets after premixing affects the size of the single crystal. Generally, the radius of a single crystal can range from 10 nm to 5 cm, and the spectral range can extend from ultraviolet (10 nm to 380 nm) to visible light (380 nm to 760 nm) to infrared (0.75 μm to 300 μm).

[0049] Perform step S4 and repeat step S3 until all channels are coated with ink, thereby obtaining a multispectral detector with different spectral absorption characteristics.

[0050] It is understandable that, at the beginning of the fabrication of the multispectral detector, the required proportion of halogen elements for each row and column of single crystals in the single crystal array was planned in advance, and the corresponding ink was deposited on the designated channels according to this plan during the fabrication process.

[0051] After all channels are deposited with ink, encapsulation and other operations can be performed under appropriate conditions according to the characteristics of the selected perovskite to obtain a multispectral detector. The encapsulation material is selected according to the application requirements, preferably any one or a mixture of several materials such as polymer, ceramic, plastic, metal, PDMS, and hydrogel.

[0052] The present invention will be further described in detail below with reference to a specific embodiment.

[0053] In this embodiment, such as Figure 5 As shown, the fabrication process requires a single-nozzle multi-channel nozzle 1, multiple controllable voltage sources 2, multiple precision flow meters 3, a movable substrate 4, and a computer 5. The channels of the single-nozzle multi-channel nozzle 1 are connected to the respective controllable voltage sources 2, precision flow meters 3, and computer 5. Changing the channel flow rate allows for the deposition of perovskite with different compositions and solvent-resistant materials. For example... Figure 6 As shown, functional materials with different absorption spectra after the fusion of multiple components are finally grown into a single crystal array 8, and the obtained single crystal array can be interconnected with the substrate 6 and the integrated circuit 7.

[0054] The method for fabricating a multispectral detector provided by this invention mainly includes the following steps:

[0055] (1) Electrode and channel preparation. The substrate was ultrasonically cleaned for 8 min in glass cleaner, acetone, isopropanol, anhydrous ethanol and deionized water in sequence. The cleaned substrate was dried in nitrogen. The prepared substrate was spin-coated with a layer of Z5214 photoresist in multiple steps in a spin coater (200 rpm, 3 s, acceleration 500 rpm / s; 500 rpm, 2 s, acceleration 500 rpm / s; 3000 rpm, 30 s, acceleration 1000 rpm / s; 4000 rpm, 5 s, acceleration 800 rpm / s), and heated on a hot plate at 95℃ for 60 s. The prepared substrate was exposed in a photolithography machine for 6.5 seconds. After that, the exposed substrate was placed in the developer and waited for the photoresist in the exposed part of the substrate to be removed by the developer (a layer of pink solution floated on the substrate). The substrate was immediately rinsed with deionized water to remove excess developer. A copper layer with a thickness of 200 nm was deposited on the developed substrate using a magnetron sputtering device. After sputtering, the substrate is placed in an acetone solution to remove the remaining photoresist, leaving only the pre-designed conductive pattern on the substrate.

[0056] (2) Preparation of hybrid printing nozzle. The experiment used a single-nozzle four-channel nozzle. The preparation method was as follows: a specially made four-channel capillary tube (SUTTER) was drawn into a 40μm nozzle at one end using a microelectrode drawing instrument; four copper wires were inserted into the other end of the four-channel capillary tube to supply power to the solution later; four dispensing needles were connected to the end with the copper wires inserted, and all connection parts were sealed with hot melt glue.

[0057] (3) Using a single-nozzle, multi-channel printhead, different proportions of perovskite ink and antisolvent are deposited in designated channels via mixed electrofluid printing. CsPbI3, CsPbBr3, CsPbCl3, and CHP solutions are added to the four channels respectively. The ratio of halogen atoms in the mixed solution can be adjusted by regulating the ink output ratio of the CsPbI3, CsPbBr3, and CsPbCl3 channels, thereby changing the band gap and achieving different band-edge absorption for color recognition. The growth of the single crystal can be controlled by adjusting the ink output ratio of the CHP channel solution. The ink output ratio of all four channels is simultaneously controlled by voltage waveform and gas path assistance.

[0058] (4) The multispectral detector is obtained by encapsulating it under suitable conditions according to the material properties. In this embodiment, UV-cured epoxy resin is used for encapsulation.

[0059] The final fabricated single-crystal arrays with different spectral detection ranges are as follows: Figure 7 As shown, single-crystal arrays of different sizes and shapes are as follows: Figure 8 As shown.

[0060] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for fabricating a multispectral detector, characterized in that, Includes the following steps: S1, Electrodes and channels are fabricated on the substrate; S2, add an anti-solvent to one channel of the single-nozzle multi-channel printhead, and add different perovskite solutions to the other channels; wherein, the printing method of the single-nozzle multi-channel printhead is hybrid electrohydrodynamic printing; S3, adjust the ink output ratio of each channel according to the required halogen element ratio, and premix the ink flowing out of each channel at the Taylor cone before depositing it in the designated channel; S4. Repeat step S3 until all channels are deposited with ink, thereby obtaining a multispectral detector with different spectral absorption characteristics. In step S3, adjusting the ink output ratio of each channel according to the required halogen element ratio includes: If each channel of a single-nozzle multi-channel printhead is connected to a controllable voltage source, the ink output ratio of each channel can be adjusted by regulating the voltage waveform so that the mixed ink droplets meet the required halogen element ratio. If each channel of a single-nozzle multi-channel printhead is connected to a precision flow pump, the ink output ratio of each channel can be adjusted by regulating the air pressure, so that the mixed ink droplets meet the required halogen element ratio.

2. The method for fabricating a multispectral detector according to claim 1, characterized in that, In step S2, the single-nozzle multi-channel nozzle is prepared in the following manner: One end of the multi-channel capillary is drawn into a single-nozzle multi-channel nozzle using a microelectrode drawing instrument; and multiple copper wires are inserted into the other end of the multi-channel capillary to supply power to the solution added to each channel.

3. The method for fabricating a multispectral detector according to claim 2, characterized in that, The material of the single-nozzle multi-channel nozzle is an insulating material.

4. The method for fabricating a multispectral detector according to claim 1, characterized in that, In S3, the ink flowing out of each channel is premixed at the Taylor cone and then deposited in the designated channel, forming a single crystal after a period of time. The proportion of ink flowing out of each channel before premixing will affect the detection range of the spectrum, and the size of the ink droplets after premixing will affect the size of the single crystal.

5. The method for fabricating a multispectral detector according to claim 4, characterized in that, The single crystal has a radius of 10nm-500μm and a detection spectral range of 300nm-800nm.

6. The method for fabricating a multispectral detector according to any one of claims 1 to 5, characterized in that, In S1, the substrate is a silicon wafer substrate, a silicon dioxide substrate, a glass substrate, an ITO glass substrate, a PDMS substrate, or any of the above substrates that have undergone hydrophobic treatment.

7. The method for fabricating a multispectral detector according to any one of claims 1 to 5, characterized in that, In S2, the antisolvent is any one or a mixture of several of the following materials: ethanol, isopropanol, butanol, ethyl acetate, chloroform, chlorobenzene, butyl acetate, dichlorobenzene, anisole, trifluorotoluene, diethyl ether, m-xylene, toluene, mesitylene, and N-cyclohexylpyrrolidone.

8. The method for fabricating a multispectral detector according to any one of claims 1 to 5, characterized in that, In step S2, the solvent of the perovskite solution is any one or a mixture of several materials selected from dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, N,N-dimethylacetamide, acetonitrile, tetramethylsilane, polycarbonate, N-methylpyrrolidone, dimethylacetamide, N,N-dimethylpropenylurea, methylammonium acetate, methylammonium formate, and butylammonium acetate.

9. A multispectral detector, characterized in that, The multispectral detector is prepared using the preparation method of the multispectral detector according to any one of claims 1-8.

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