Preparation method of light-emitting pixel board, spectrum and position correlated imaging system and method

Abstract

The invention provides a preparation method of a light-emitting pixel board and a spectrum and position correlated imaging system and method, and the system comprises an illumination module which is used for emitting a light source; the spectrum modulation module comprises a target object and a light-emitting pixel plate, the target object is provided with a hollow part, the hollow part forms transmission light under the irradiation of the emission light source, the transmission light reaches the light-emitting pixel plate, and different pixels of the light-emitting pixel plate are excited to generate visible light with different wavelengths; the receiving module is used for receiving one-dimensional spectral information sent by all excited perovskite materials to obtain spectral information containing target pixel position information; and the computer is used for carrying out spectrum unmixing processing and operation on the spectrum information, and recovering a binary image of the target object according to the incidence relation between the spectrum and the spatial position. According to the invention, the spectrum and the spatial position are correlated, the spatial information is reconstructed by collecting the spectral information, and the spectrum and spatial position correlated imaging of the perovskite nanocrystalline material and wavelength division multiplexing is realized.

Description

Technical Field

[0001] The present invention belongs to the field of optical computing, and in particular relates to a method for preparing a luminous pixel panel, and a spectrum and position correlation imaging system and method. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] After entering the information age, the growth of information volume and information processing needs has reached an unprecedented level. Traditional electronic computing systems have been unable to meet the growing demand for information processing and computing power. Thanks to the advantages of optical systems such as high speed, high bandwidth, high parallelism, low loss, and low crosstalk, optical computing has become a research hotspot in recent years to solve the speed and power consumption bottlenecks of traditional electronic computing systems.

[0004] Generally speaking, optical computing can be defined as "a computing scheme that uses photons as physical carriers to process information." According to the different computing processes, it can be generally divided into two categories: digital optical computing and analog optical computing. The main idea of ​​digital optical computing is to imitate digital electronic computers and construct digital photonic computers based on Boolean operations and photonic transistors / optical logic gates. The main idea of ​​analog optical computing is to use the propagation process of light in the medium to directly process optical analog signals in the frequency domain or time domain.

[0005] Initially, the main focus of optical computing was on applications that connected various parts of computers, such as communications, or more basic systems with some optical functions or components. Wavelength Division Multiplexing (WDM) technology, commonly used in optical fiber communication systems, can use multiple wavelengths to transmit signals of different channels on the same optical fiber at the same time.

[0006] In recent years, various basic components that can eventually form optical computers, such as optical logic gates, optical switches, neural networks, and spatial light modulators, have also been developed. It is worth noting that optical computing is rarely used in the field of imaging. By drawing on the huge bandwidth of WDM technology and applying it to the imaging process, while using multiple wavelengths to transmit image information at different spatial locations, the spatial scanning process is transformed into a process of analyzing each wavelength signal, which can provide a way to build an all-optical imaging system.

[0007] Metal halide perovskite (CsPbX 3, X=Cl, Br, I) as a new type of optoelectronic material, has attracted much attention due to its simple preparation process, high photoelectric conversion efficiency, high light absorption coefficient, and large carrier mobility. It has been widely used in solar cells, light-emitting diodes (LEDs), lasers, and photodetectors. Metal halide perovskites, as a colloidal semiconductor nanocrystalline material, are being studied in depth; and the most important thing to build a spectral and spatial correlation imaging system is to use the photoluminescence properties of perovskite nanocrystals, that is, when a certain voltage or light field is applied to it, it will emit light of a specific frequency.

[0008] In order to obtain emission spectra of different wavelengths, perovskite nanocrystals usually need to be prepared multiple times. This is because the emission wavelength is closely related to the chemical composition, size and morphology of the nanocrystals. By adjusting the chemical composition of the material, such as selecting different cations or anions, its optical properties can be significantly changed. In addition, the size of the nanocrystals also directly affects the emission characteristics, so the reaction conditions, such as temperature and time, must be precisely controlled during the synthesis process to obtain the desired size. Current research results show that the band gap of perovskite nanocrystals is closely related to their halide composition. By adjusting the ratio of halide perovskite nanocrystals to achieve anion exchange, its band gap can be easily regulated, and its photoluminescence wavelength will also change accordingly, and the luminescence spectrum can cover the entire visible light band.

[0009] Perovskite nanocrystals prepared by mixing halide perovskite materials have the characteristics of narrow emission linewidth, wide color gamut and high quantum yield, which helps to build spectral and spatial correlation imaging systems and realize optical computing imaging. Summary of the invention

[0010] In order to solve the above problems, the present invention proposes a method for preparing a luminous pixel panel, a spectrum and position correlation imaging system and method. The present invention utilizes an in-situ preparation method to synthesize a halide perovskite material as a luminous pixel panel, correlates the spectrum with the spatial position, reconstructs the spatial information by collecting spectral information, realizes the spectrum and spatial position correlation imaging of perovskite nanocrystal materials and wavelength division multiplexing, restores the two-dimensional image information by scanning the one-dimensional spectral information, and realizes the dimensionality reduction of the scanned data by means of optical information processing.

[0011] According to some embodiments, the present invention adopts the following technical solutions:

[0012] A method for preparing a light-emitting pixel panel comprises the following steps:

[0013] The perovskite solution was prepared by hot injection method;

[0014] Cleaning substrates with multiple dispensing locations;

[0015] Perovskite solutions with different ratios are dispensed at different positions on the substrate. After the perovskite solutions are mixed and solidified, a light-emitting pixel panel with different perovskite materials at different pixel positions is obtained.

[0016] As an optional embodiment, the process of preparing a perovskite solution by a hot injection method includes: the process of preparing a perovskite solution by a hot injection method includes mixing cesium carbonate, oleic acid and 1-octadecene in a certain proportion and placing them in a three-necked flask, wherein the mass ratio of the three reactants is about 1:2:30. Vacuum drying for a period of time at a first set temperature, then introducing a rare gas into the mixing container and heating to a second set temperature until all cesium carbonate reacts with oleic acid, and the first set temperature and the second set temperature are both greater than a predetermined value;

[0017] 1-Octadecene and PbX 2 The salt mixture is mixed, wherein the molar ratio of the two mixtures is about 94:1, X is Cl, Br or I, and vacuum dried at a set temperature for a period of time, a rare gas is introduced into the mixing container, and dry oleylamine and oleic acid are injected. When PbX 2 After the salt is completely dissolved, the temperature is raised to 140-200°C, and a certain amount of cesium oleate solution is injected. After the reaction, the reaction mixture is cooled to room temperature using a water bath method; methyl acetate is added to the mixed solution to precipitate perovskite nanocrystals; the perovskite nanocrystals are separated by centrifugal precipitation; and finally, the perovskite nanocrystals are redispersed in an organic solvent, n-hexane, to form a long-term stable perovskite solution.

[0018] As an optional embodiment, the process of dispensing perovskite solutions with different ratios at different positions on the substrate includes: providing a plurality of grooves on the substrate, respectively dispensing CsPbCl 3 、CsPbBr 3 and CsPbI 3 The n-hexane solution and polydimethylsiloxane were mixed as three original solutions. The proportions of the three original solutions in different grooves were different. CsPb(Cl x Br 1-x ) 3 or CsPb(Br x I 1-x ) 3 Solution, 0≤x≤1.

[0019] A spectrum and position correlation imaging system, comprising:

[0020] A lighting module, used for emitting light source;

[0021] A spectral modulation module, comprising a target object and a light-emitting pixel plate prepared by the above method, wherein the target object has a hollow portion, and the hollow portion forms transmitted light under the irradiation of an emitting light source, and the transmitted light reaches the light-emitting pixel plate to obtain an image with the same spatial distribution as the hollow portion of the target object, and different pixels of the light-emitting pixel plate are excited to generate visible light of different wavelengths;

[0022] A receiving module, used to receive one-dimensional spectral information emitted by all excited perovskite materials, and obtain spectral information containing target pixel position information;

[0023] The computer is used to receive and store the spectral information, perform spectral unmixing processing and calculation on the spectral information, and restore the binary image of the target object according to the correlation between the spectrum and the spatial position.

[0024] As an optional implementation, the target object and / or the light-emitting pixel panel may be rotated.

[0025] As an optional implementation, the peaks of pixel spectra at adjacent positions on the luminous pixel panel are not adjacent, and the difference values ​​between adjacent pixels are as average as possible, that is, the variance of the difference values ​​between adjacent pixels is less than a predetermined value.

[0026] A spectrum and position correlation imaging method comprises the following steps:

[0027] Emitting light source;

[0028] The hollow part of the target object forms transmitted light under the irradiation of the emitting light source. The transmitted light reaches the luminous pixel board and obtains an image with the same spatial distribution as the hollow part of the target object. Different pixels of the luminous pixel board are excited to generate visible light of different wavelengths.

[0029] Receive one-dimensional spectral information emitted by all excited perovskite materials, and obtain spectral information containing target pixel position information;

[0030] The position of the light-emitting pixel plate is rotated by a set angle, and the above process is repeated after the rotation, and performed multiple times;

[0031] All spectral information is received, spectral unmixing and calculation are performed on the spectral information, and the binary image of the target object is restored according to the correlation between the spectrum and the spatial position.

[0032] As an optional implementation, the luminescent pixel panel is calibrated in advance, and the calibration process includes: replacing the target object with a shading sheet, the shading sheet is provided with a hollow portion the size of a pixel position, and only light from a certain pixel position is allowed to pass through at a time, and only the spectrum of one perovskite film is collected each time. After the collection is completed, the shading sheet is replaced, and each shading sheet has a different hollow portion, and the above operation is repeated until the spectra of all pixels are collected to complete the calibration process of the luminescent pixel panel.

[0033] As an optional implementation, the process of rotating the position of the light-emitting pixel panel at a set angle includes rotation angles of 0°, 90°, 180° and 270°, respectively, and a set of spectral information is collected at each rotation angle.

[0034] As an optional implementation, in the process of performing spectral unmixing processing and calculation on the spectral information, multiple groups of spectral information are combined and spectral unmixing is performed using a multivariate linear regression algorithm.

[0035] As an optional implementation, the rotating light-emitting pixel plate in the above process is replaced by rotating the target object.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention provides a spectrum and spatial position correlation imaging technology that uses perovskite nanocrystal materials and wavelength division multiplexing technology. The target image can be restored by spectral unmixing and decomposing the collected spectral information; light information processing is applied to imaging technology, so that the process of scanning two-dimensional image information in traditional imaging technology is converted into scanning one-dimensional spectral information, which reduces the dimension of information collection and reduces the system's requirements for detection devices.

[0038] The method proposed in the present invention for in-situ preparation of halide perovskite materials using anion exchange can achieve a more uniform distribution of nanocrystal components, making the photoluminescence peak position in the visible light band more refined; it reduces the multiple and multi-step perovskite nanocrystal synthesis process and greatly improves the preparation efficiency.

[0039] The spectral-spatial correlation imaging technology proposed in the present invention can restore the target image from one-dimensional spectral information, greatly improving the efficiency of information acquisition; it can reduce the demand for high-performance detection devices in optical imaging and reduce the overall cost of the system; it can be applicable to a variety of spectral ranges by changing the use of nanocrystalline materials, and has high potential application value in the fields of biological imaging and environmental testing; it can achieve rapid imaging, which is suitable for real-time monitoring and dynamic observation, and meets high-timeliness application requirements.

[0040] The all-optical imaging process proposed in the present invention can realize parallel and rapid processing of large-volume imaging data, which is suitable for observation and recording of fast dynamic scenes; it can make the system more compact, realize portable application, and facilitate on-site detection and field monitoring.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0043] Figure 1 A principle block diagram of a spectrum and position correlation imaging system according to an embodiment;

[0044] Figure 2 For one embodiment, CsPbX 3 Schematic diagram of the processing process of perovskite light-emitting pixel panel;

[0045] Figure 3 A schematic diagram of the structure of a spectrum and position correlation imaging system according to an embodiment;

[0046] Figure 4 A schematic diagram of system imaging results according to an embodiment.

[0047] Among them, 1. light source, 2. target object, 3. luminous pixel board, 4. detector, 5. computer. DETAILED DESCRIPTION

[0048] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0049] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0050] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0051] In the absence of conflict, the embodiments in this application and the features in the embodiments may be combined with each other.

[0052] Embodiment 1

[0053] A method for preparing a light-emitting pixel panel comprises the following steps:

[0054] The perovskite solution was prepared by hot injection method;

[0055] Cleaning substrates with multiple dispensing locations;

[0056] Perovskite solutions with different ratios are dispensed at different positions on the substrate. After the perovskite solutions are mixed and solidified, a light-emitting pixel panel with different perovskite materials at different pixel positions is obtained.

[0057] In this embodiment, the process of preparing the perovskite solution by the hot injection method includes: mixing cesium carbonate, octadecene and oleic acid, vacuum drying for a period of time at a first set temperature, then introducing a rare gas into the mixing container and heating to a second set temperature until all the cesium carbonate reacts with the oleic acid, and the first set temperature and the second set temperature are both greater than a predetermined value;

[0058] Octadecene and PbX 2 The salt mixture, X is Cl, Br or I, is vacuum dried at a set temperature for a period of time, a rare gas is introduced into the mixing container, and dry oleylamine and oleic acid are injected. When PbX 2 After the salt is completely dissolved, the temperature is raised to 140-200°C, and a certain amount of cesium oleate solution is injected. After the reaction, the reaction mixture is cooled to room temperature using a water bath method; methyl acetate is added to the mixed solution to precipitate perovskite nanocrystals; the perovskite nanocrystals are separated by centrifugal precipitation; and finally, the perovskite nanocrystals are redispersed in an organic solvent, n-hexane, to form a long-term stable perovskite solution.

[0059] In this embodiment, the process of dispensing perovskite solutions with different ratios at different positions on the substrate includes: providing a plurality of grooves on the substrate, respectively dispensing CsPbCl 3 、CsPbBr 3 and CsPbI 3 The n-hexane solution and polydimethylsiloxane were mixed as three original solutions. The proportions of the three original solutions in different grooves were different. CsPb(Cl x Br 1-x ) 3 or CsPb(Br x I 1-x ) 3 Solution, 0≤x≤1.

[0060] Embodiment 2

[0061] The method for preparing the perovskite light-emitting pixel panel used in this embodiment (taking cesium lead halide perovskite nanocrystals as an example) comprises the following steps:

[0062] (1) Preparation of perovskite solution by hot injection method:

[0063] Preparation of precursor: 0.407 g of cesium carbonate (Cs 2 CO 3 ) was placed in a 50 mL three-necked flask together with 20 mL 1-octadecene (ODE) and 1.25 mL oleic acid (OA), and dried under vacuum at 120 °C for 1 h. Then, a noble gas was introduced into the three-necked flask and heated to 150 °C until all Cs 2 CO 3 Reacts with OA. Since cesium oleate precipitates from ODE at room temperature, it must be preheated to 80°C before injection.

[0064] Perovskite nanocrystals (CsPbX 3 Synthesis of NCs: 5 mL ODE and 0.188 mmol PbX 2 The salt was placed in a 25 mL three-necked flask and dried under vacuum at 100 °C for 1 h. Subsequently, 0.5 mL of dry oleylamine (OLA) and 0.5 mL of dry OA were injected under a rare gas atmosphere at 120 °C. 2 After the salt is completely dissolved, the temperature is raised to 140-200°C, and 0.4 mL of cesium oleate solution is quickly injected. After a few seconds of reaction, the reaction mixture is cooled to room temperature using a water bath. Subsequently, methyl acetate is added to the mixed solution to make CsPbX 3 NCs precipitation; CsPbX was separated by centrifugal precipitation 3 NCs; finally, CsPbX 3 NCs were redispersed in the organic solvent n-hexane to form a long-term stable perovskite solution.

[0065] (2) Dispensing glue on the substrate to prepare the perovskite light-emitting pixel panel:

[0066] The glass sheet (with grooves) was cleaned and CsPbCl 3 、CsPbBr 3 and CsPbI 3 The n-hexane solution of PDMS (mass ratio of A agent: B agent = 10:1) was mixed as three original solutions, and the three original solutions were dispensed on the corresponding positions of the glass substrate in different proportions by using the dispensing function of the inkjet printer. After the solutions were mixed and solidified, a light-emitting pixel plate with different perovskite materials at different pixel positions was obtained.

[0067] The glass sheet cleaning is to put the glass sheet into a container filled with acetone for ultrasonic cleaning for twenty minutes, put it into an isopropanol solution for ultrasonic cleaning for twenty minutes after it is dried, and then put it into a vacuum plasma cleaning machine for cleaning after drying, so as to improve the adhesion effect of the material on the surface of the glass sheet.

[0068] Embodiment 3

[0069] A spectrum and spatial position correlation imaging system, such as Figure 1 As shown, it includes an illumination module, a spectrum modulation module, a receiving module and a computer:

[0070] The lighting module: In this embodiment, a 365nm ultraviolet LED lamp bead array is used as the lighting light source; after the ultraviolet light source irradiates the hollow target object, part of the light is reflected or absorbed, and the rest of the light passes through the target and reaches the light-emitting pixel board, obtaining an image with the same spatial distribution as the target object.

[0071] Of course, in other embodiments, other lighting devices may be selected as light sources.

[0072] The spectrum modulation module: uses the perovskite light-emitting pixel panel prepared in the above embodiment to perform spectrum modulation on the light transmitted through the target object; the light-emitting pixel panel is a pixel array composed of perovskite material, and the stimulated radiation spectra of the perovskite material at different pixels in the array are different. According to the transmitted light of the hollowed-out target object, different pixels in the light-emitting pixel panel are excited to generate visible light of different wavelengths, which are directly emitted and enter the receiving module.

[0073] The receiving module comprises a detector, which is used to simultaneously receive one-dimensional spectral information emitted by all excited perovskite materials to obtain spectral information containing target pixel position information.

[0074] The computer receives and stores the collected spectral information, performs spectral unmixing processing and calculation on the data through an algorithm, and restores a binary image of the target object.

[0075] The computer processing process can adopt existing technology, which will not be described in detail here.

[0076] The photoluminescence (PL) spectrum of each pixel of the prepared luminescent pixel panel needs to be calibrated in advance.

[0077] The calibration process includes: Figure 3 The light path is constructed as shown in the system diagram, and the light shield is replaced at the position where the transmissive target is placed; the light shield also adopts a hollow design, and only allows ultraviolet light at a certain pixel position to pass through each time, so that only one perovskite film PL spectrum is collected each time. After the collection is completed, the light shield is replaced, and the above operation is repeated until the spectra of all pixels are collected to complete the calibration process of the pixel board.

[0078] The resolution of the luminescent pixel board is directly related to the ratio of the three original solutions. The more the ratio, the more different perovskite materials are obtained, and the luminescent pixel board has a higher resolution. Here is the characterization experiment theory, taking a 5×5 luminescent pixel board as an example. For this luminescent pixel board, A1-A25 can be used from left to right and from top to bottom; at the same time, 25 different perovskite materials are obtained according to the ratio of 25 different original solutions. Its photoluminescence spectrum range is 450-725nm, and it is numbered from small to large with F1-F25 according to the PL spectrum peak position. In order to explore whether the placement order or arrangement of the film has an effect on the subsequent spectrum and position correlation calculation results, the sequential arrangement (F1 is placed at the A1 position) and other arrangements are compared through simulation experiments. The experimental results show that for non-random binary targets, the image results obtained using random arrangement are more similar to the target than the image results using sequential arrangement. Therefore, the system uses luminescent pixel boards with different perovskite materials randomly arranged for experiments.

[0079] The process of associating the spectrum with the position and restoring the target image is as follows: the hollow part of the transmissive target is fixed, and when the light emitted by the light source passes through the target, only the signal light with the same spatial distribution as the target object can pass through and reach the light-emitting pixel board.

[0080] For the calibrated light-emitting pixel board, all pixel positions are fixed. Combined with the arrangement of the perovskite film, the film PL spectrum at each position can also be determined, thus realizing the association between the spectrum and the pixel position. The ultraviolet light from the target excites the perovskite film at the corresponding pixel position to emit light. After diffuse reflection from the integrating sphere, this part of the light is evenly distributed on its inner wall. Finally, the information is collected by the detector and transmitted to the computer, completing the collection of a set of spectral data.

[0081] In order to restore the target image more accurately, this embodiment rotates the light-emitting pixel plate, and the rotation angles are 0°, 90°, 180° and 270° respectively. Each rotation angle collects a set of information, that is, a total of four sets of spectral information are collected for each target. Since the target remains unchanged and the light-emitting pixel plate is rotated, the positions of the excited pixels are the same during the four excitations of the light-emitting pixel plate, and the excited perovskite materials are different, which leads to different spectral information. The four sets of information are combined and the multivariate linear regression algorithm is used for spectral unmixing to restore the target image.

[0082] The process of determining the arrangement order of the light-emitting pixel panel in this embodiment is as follows:

[0083] First, consider arranging 100 simulated spectral curves in order to explore the impact of half-width on the calculation results. When the half-width of the material excitation light is relatively narrow, the calculation results in the simulation experiment are completely consistent with the target image. When the half-width of the material excitation light is too wide, the target image cannot be calculated. By comparing the above two calculation results, it can be seen that the error mainly occurs between adjacent pixels.

[0084] The reasons are as follows: the target used for simulation calculation is continuous (compared to a random binary matrix), and the peak position of each pixel after being excited by ultraviolet light is relatively close, which may cause the collected spectral information to be concentrated in a certain band, or cause information crosstalk, thereby increasing the difficulty of subsequent multivariate linear regression calculations. This is the main reason for the error in the simulation experiment. Therefore, the position arrangement of different perovskite materials can be planned so that the information is dispersed in each band, and the error can be reduced as much as possible from the algorithm calculation aspect.

[0085] In order to achieve the above goals, this embodiment has two requirements for the arrangement order: First, the peak positions of the pixel spectra at adjacent positions are not adjacent; for this requirement, each spectrum is numbered from 1 to n (n is the total number of spectra), and the serial numbers are randomly shuffled and arranged into a two-dimensional square matrix, and then the absolute value of the difference between the serial numbers of each pixel and the adjacent pixels is calculated, and finally all the results are summed to obtain the "difference value" corresponding to an arrangement method. The larger the value, the greater the difference in the spectral peak positions of adjacent pixels. For a 10×10 resolution luminous pixel panel, there are 100 different spectral curves and 100! kinds of arrangements ("!" represents factorial, that is, 100!=1×2×3×...×100), which is undoubtedly a very huge amount of calculation. Therefore, a simulation experiment was conducted to generate 3 million sets of different arrangements using simulation and calculate their difference values.

[0086] After calculating the difference value, it is also necessary to ensure that the difference value between adjacent pixels is as average as possible to avoid placing spectra No. 1 and No. 100 at adjacent pixel positions in order to obtain a larger difference value. According to the calculated difference value distribution, a threshold is set to filter the arrangement method, and the part above the threshold is retained. The variance of the difference value of adjacent pixel numbers is further calculated to obtain a set of sorting results with the smallest variance, which facilitates the subsequent production of the luminous pixel board.

[0087] The above system simplifies the process of scanning two-dimensional spatial information in traditional imaging technology, applies the optical information processing process based on wavelength division multiplexing technology to imaging technology, uses perovskite material luminous pixel panels to convert target spatial information into spectral information, and realizes imaging of target objects by analyzing one-dimensional spectral information.

[0088] Embodiment 4

[0089] A method for imaging by associating spectral information with spatial position. A luminescent pixel panel made of perovskite nanocrystals can be excited by ultraviolet light, and the order of thin film arrangement corresponds to the spatial position one by one, thereby realizing the recovery of the spatial information of the target object in the form of wavelength division multiplexing.

[0090] This method is implemented with the help of the system of embodiment three.

[0091] In order to realize that different spectra represent different spatial positions and collect one-dimensional spectral information to restore the two-dimensional image, the optical information processing imaging method is mainly based on the idea of ​​using the luminous pixel panel as the hub of the association between the spectrum and the position, and obtaining the spectral information containing the spatial information of the target object, and looking for a solution with the central idea of ​​using the photoluminescence characteristics of nanocrystals for spectral modulation.

[0092] The specific steps include:

[0093] (1) Figure 2 As shown, perovskite nanocrystal materials are prepared and processed into light-emitting pixel panels;

[0094] (2) Building the imaging system provided in Example 3;

[0095] (3) Adding perovskite light-emitting pixel panels to the imaging system;

[0096] (4) The system detects the target and acquires data to obtain one-dimensional spectral information;

[0097] (5) Use the spectral unmixing algorithm to restore the target image.

[0098] Among them, step (1) of this embodiment can be performed by means of the method provided in embodiment 1 or embodiment 2, or the following process can be adopted:

[0099] The photoluminescence properties of nanocrystals are closely related to their halogen composition. By controlling the composition ratio of halogen elements in cesium lead halide perovskite, its band gap can be adjusted to make the PL spectrum tunable in the visible light range. By using this material to map ultraviolet light to different wavelengths, wavelength division multiplexing can be achieved and the image can be restored using spectral information.

[0100] Cesium lead halide perovskite nanocrystals (CsPbX 3 NCs) light-emitting pixel panel processing, which includes the preparation of CsPbX 3 NCs material and deposition on substrate. 3 NCs materials were prepared by hot injection. 2 CO 3Put it into a three-necked flask together with ODE and OA, gradually raise the temperature to 120℃ while maintaining magnetic stirring, and keep it at this temperature for 1 hour. In this process, the solution should always be kept in a vacuum state. The purpose of this step is to remove water from the solution. Then, inert gas is introduced into the three-necked flask and heated to 150℃ for a period of time. When all the precipitates in the solution are observed to be dissolved, all Cs 2 CO 3 Reacts with OA to form cesium oleate precursor. Since cesium oleate will precipitate from ODE at room temperature, it must be preheated before use.

[0101] After the precursor solution is prepared, take another three-necked flask and place PbX 2 Salt and ODE were loaded and dried in vacuum at 100 °C to remove water from the solution. Then inert gas was introduced into the three-necked flask and dried OLA and OA were injected. 2 After the salt is completely dissolved, the temperature is directly raised to 140-200°C, and an appropriate amount of cesium oleate precursor is quickly injected. It can be found that the solution in the three-necked flask glows when irradiated by ultraviolet light. 3 NCs rapidly nucleate and grow. This process is very rapid. In order to obtain nanocrystals of suitable size, the reaction mixture needs to be quickly cooled to room temperature by water bath after the reaction. At this point, the material preparation process is basically completed. 3 In addition to NCs, it also contains unreacted raw materials and other substances produced during the reaction, so the solution needs to be purified. By adding methyl acetate to the colloidal solution, it can be observed that nanocrystals gradually precipitate and the solution becomes turbid; CsPbX can be separated by centrifugal precipitation. 3 NCs. The above process can be repeated one or two times depending on the material preparation. After the purification process, the required CsPbX 3 NCs material, and finally disperse it in the organic solvent n-hexane to obtain a long-term stable perovskite solution.

[0102] When preparing the light-emitting pixel plate, common glass is used as the film substrate, and grooves are made on the glass plate. The glass plate is placed in beakers containing acetone and isopropanol in turn, and ultrasonically cleaned for 20 minutes each. After drying, the surface is treated in a vacuum plasma cleaner. After the glass plate is treated, the perovskite film is prepared at the existing groove position through a dispensing process. CsPbCl 3 、CsPbBr 3 and CsPbI 3 The n-hexane solution was mixed with an appropriate amount of PDMS as three original solutions. The proportions of the three original solutions in different grooves were different. CsPb(Clx Br 1-x ) 3 or CsPb(Br x I 1-x ) 3 solution, 0≤x≤1. After the solution is mixed and solidified, a light-emitting pixel plate with different perovskite materials at different groove positions can be obtained.

[0103] The constructed imaging system can be as shown in Example 3, and may also include an illumination module, a spectral modulation module, a receiving module and a computer. After the illumination module illuminates the target object 2 through the ultraviolet light source 1, part of the light is transmitted to the light-emitting pixel panel 3, while the rest of the light is blocked and does not participate in the subsequent imaging process.

[0104] The spectral modulation module uses a perovskite light-emitting pixel panel 3. The ultraviolet light transmitted through the hollowed-out part of the target object 2 will excite the perovskite material at the corresponding pixel position, emitting light of different wavelengths, which will be collected by the subsequent receiving module.

[0105] The receiving module is a detector responsible for receiving wavelength information, replacing the CCD, CMOS and other detection devices used in traditional imaging technology.

[0106] The collected spectral information will be uploaded to the computer 5, and the target image will be restored through spectral unmixing based on the correlation between the spectrum and the spatial position.

[0107] This embodiment uses ultraviolet light or other light sources that can excite perovskite materials for illumination. When the light irradiates the transmissive target, the perovskite corresponding to the hollowed-out portion of the target will be excited, because the target corresponds to the spatial position of the light-emitting pixel plate. Figure 3 The material at the position corresponding to the number "5" in the figure is excited. The perovskite materials at different spatial positions are different, and the wavelengths of the light after being excited are different, which realizes the correlation between the spectrum and the position. The excitation light undergoes spectral aliasing before reaching the detector. Finally, the detector collects the mixed spectral information and transmits it to the computer, that is, a set of data is collected. In order to reduce the error between the imaging result and the target image, the light-emitting pixel plate is rotated, and the above process is repeated every time it is rotated to collect a set of data, and a total of four rotations are made.

[0108] like Figure 4 As shown, although the four sets of spectral data are different, their corresponding targets are the same, so the four sets of data can be combined. Combined with the photoluminescence characteristics of perovskite nanocrystals, the spectral information can be associated with the spatial information, that is, each photoluminescence spectrum represents a specific position, and the strength or presence of the spectral signal represents whether there is target image information at that position. The collected spectral information can be decomposed by spectral unmixing to restore the target image.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention without creative labor shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a light-emitting pixel panel, characterized in that: The following steps are involved: The perovskite solution was prepared by hot injection method; Cleaning substrates with multiple dispensing locations; Perovskite solutions with different ratios are dispensed at different positions on the substrate. After the perovskite solutions are mixed and solidified, a light-emitting pixel panel with different perovskite materials at different pixel positions is obtained.

2. A method for preparing a light-emitting pixel panel as claimed in claim 1, characterized in that: The process of preparing a perovskite solution by using a hot injection method comprises: the process of preparing a perovskite solution by using a hot injection method comprises mixing cesium carbonate, octadecene and oleic acid, vacuum drying at a first set temperature for a period of time, then introducing a rare gas into a mixing container and heating to a second set temperature until all the cesium carbonate reacts with the oleic acid, wherein the first set temperature and the second set temperature are both greater than a predetermined value; Octadecene and PbX2 salt are mixed, where X is Cl, Br or I, and vacuum dried at a set temperature for a period of time. A rare gas is introduced into the mixing container, and dry oleylamine and oleic acid are injected. When the PbX2 salt is completely dissolved, the temperature is increased to 140-200°C, and a certain amount of cesium oleate solution is injected. After the reaction, the reaction mixture is cooled to room temperature by a water bath method; methyl acetate is added to the mixed solution to precipitate perovskite nanocrystals; the perovskite nanocrystals are separated by centrifugal precipitation; and finally, the perovskite nanocrystals are redispersed in an organic solvent, n-hexane, to form a long-term stable perovskite solution.

3. A method for preparing a light-emitting pixel panel as claimed in claim 1, characterized in that: The process of dispensing perovskite solutions with different ratios at different positions on the substrate includes: providing a plurality of grooves on the substrate, mixing n-hexane solutions of CsPbCl3, CsPbBr3 and CsPbI3 with polydimethylsiloxane as three original solutions, and the proportions of the three original solutions at different grooves are different, and forming CsPb(Cl x Br 1-x )3 or CsPb(Br x I 1-x )3 solution, 0≤x≤1.

4. A spectrum and position correlation imaging system, characterized in that: include: A lighting module, used for emitting light source; A spectral modulation module, comprising a target object and a light-emitting pixel plate prepared by the above method, wherein the target object has a hollow portion, and the hollow portion forms transmitted light under the irradiation of an emitting light source, and the transmitted light reaches the light-emitting pixel plate to obtain an image with the same spatial distribution as the hollow portion of the target object, and different pixels of the light-emitting pixel plate are excited to generate visible light of different wavelengths; A receiving module, used to receive one-dimensional spectral information emitted by all excited perovskite materials, and obtain spectral information containing target pixel position information; The computer is used to receive and store the spectral information, perform spectral unmixing processing and calculation on the spectral information, and restore the binary image of the target object according to the correlation between the spectrum and the spatial position.

5. A spectrum and position correlation imaging system as claimed in claim 4, characterized in that: The target object and / or the light-emitting pixel panel can rotate; Alternatively, the peak positions of the pixel spectra at adjacent positions on the luminous pixel panel are not adjacent, and the difference values ​​between adjacent pixels are as average as possible, that is, the variance of the difference values ​​between adjacent pixels is less than a predetermined value.

6. A spectrum and position correlation imaging method, characterized in that: The following steps are involved: Emitting light source; The hollow part of the target object forms transmitted light under the irradiation of the emitting light source. The transmitted light reaches the luminous pixel board and obtains an image with the same spatial distribution as the hollow part of the target object. Different pixels of the luminous pixel board are excited to generate visible light of different wavelengths. Receive one-dimensional spectral information emitted by all excited perovskite materials, and obtain spectral information containing target pixel position information; The position of the light-emitting pixel plate is rotated by a set angle, and the above process is repeated after the rotation, and performed multiple times; All spectral information is received, spectral unmixing and calculation are performed on the spectral information, and the binary image of the target object is restored according to the correlation between the spectrum and the spatial position.

7. A spectrum and position correlation imaging method as claimed in claim 6, characterized in that: The luminous pixel panel is calibrated in advance, and the calibration process includes: replacing the target object with a shading sheet, the shading sheet is provided with a hollow portion of the size of a pixel position, and only light at a certain pixel position is allowed to pass through each time, and only the spectrum of one perovskite film is collected each time. After the collection is completed, the shading sheet is replaced, and the hollow portion of each shading sheet is different. The above operation is repeated until the spectra of all pixels are collected to complete the calibration process of the luminous pixel panel.

8. The spectrum and position correlation imaging method according to claim 6, characterized in that: The process of rotating the position of the light-emitting pixel panel at a set angle includes rotation angles of 0°, 90°, 180° and 270°, respectively, and a set of spectral information is collected at each rotation angle.

9. The spectrum and position correlation imaging method according to claim 6, characterized in that: The process of spectral unmixing and calculation of spectral information combines multiple groups of spectral information and uses a multivariate linear regression algorithm to perform spectral unmixing.

10. A spectrum and position correlation imaging method according to any one of claims 6 to 9, characterized in that: Replace the rotating glowing pixel board with a rotating target object.

Images