Infrared hyperspectral imaging detector and preparation method and imaging method thereof

Abstract

The present disclosure relates to an infrared hyperspectral imaging detector and a preparation method and imaging method thereof, and belongs to the field of infrared detection. The infrared hyperspectral imaging detector comprises a readout circuit, a colloidal quantum dot infrared detection unit and a random optical filter array; wherein the readout circuit has an array of pixel circuits; the colloidal quantum dot infrared detection unit is coupled to one side of the readout circuit; the colloidal quantum dot infrared detection unit is arrayed on one side of the readout circuit; the random optical filter array is coupled to the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the random optical filter array comprises an array of optical filters, the light transmission bands of different optical filters are different, and the light transmission bands of the optical filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit. Thus, the random optical filter array is directly coupled with the area array readout circuit coupled with the colloidal quantum dot infrared detection unit, the structure is simplified, real-time imaging can be achieved, and the spatial resolution is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of photoelectric detection, and in particular to an infrared hyperspectral imaging detector and a preparation method and imaging method thereof. BACKGROUND

[0002] In the field of photoelectric sensors / photoelectric detection, hyperspectral infrared imagers / detectors are an important application in photoelectric sensors. Based on the hyperspectral infrared imager, important information such as spectral information of different wavebands and energy distribution of different waveband photons can be obtained, and therefore the hyperspectral infrared imager plays an important role in the fields of biological medicine, chemical and physical property analysis, and heat and temperature distribution analysis. Unlike general red (Red), green (Green), and blue (Blue) three-channel visible light sensors or infrared wide waveband detectors that lose a large amount of waveband information, a hyperspectral infrared detector can obtain hyperspectral information of each waveband in the infrared range through different narrow channels. The hyperspectral infrared detector can capture continuous narrow waveband spectral information of a target object. Compared with the tiny spectral differences that cannot be distinguished by a traditional detector, the hyperspectral infrared detector can obtain continuous and fine spectral information, recognize specific materials through spectral feature matching, and realize hyperspectral imaging through algorithm fusion to analyze the proportions of each component, and therefore the hyperspectral infrared detector has important applications in the fields of industrial detection, agriculture, environmental monitoring, and military.

[0003] The hyperspectral detector in the related art has the following problems: first, the hyperspectral area array detector in the related art is generally a photoelectric detector based on a silicon material, and is usually applied to a visible light waveband, and cannot detect an infrared waveband. A detector that is extended to the infrared waveband is usually a single-point imaging system, and the single-point imaging system needs to rely on scanning imaging or coded imaging to realize hyperspectral imaging, and therefore the single-point imaging system has a long imaging time and a low resolution; second, different response waveband infrared bulk materials are difficult to integrate onto the same readout circuit substrate, and the traditional bulk materials that realize infrared response are limited by flip-chip bonding technology, and cannot be directly coupled with a filter. The traditional bulk materials usually need a front optical system to split light, and therefore the complexity of the optical system is increased; third, the hyperspectral imaging detector based on light splitting needs to obtain data through spatial or spectral scanning, and therefore the hyperspectral imaging detector has a low frame rate and a slow speed, and cannot realize real-time imaging; fourth, although the hyperspectral infrared detector based on a pixel-level filter method can realize real-time imaging, the spatial resolution of the hyperspectral infrared detector is seriously reduced. SUMMARY

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides an infrared hyperspectral imaging detector and a preparation method and imaging method thereof.

[0005] The present disclosure provides an infrared hyperspectral imaging detector, comprising:

[0006] A readout circuit has a pixel circuit arranged in an array;

[0007] A colloidal quantum dot infrared detection unit is coupled to one side of the readout circuit; the colloidal quantum dot infrared detection unit is arranged in an array on one side of the readout circuit;

[0008] A random optical filter array is coupled to a side of the colloidal quantum dot infrared detection unit away from the readout circuit; the random optical filter array includes optical filters arranged in an array, different optical filters have different light transmission wavelength bands, and the light transmission wavelength bands of the optical filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.

[0009] Optionally, the optical filters include first-type optical filters and second-type optical filters;

[0010] In a direction of the readout circuit pointing to the random optical filter array, the first-type optical filters include two oppositely arranged distributed Bragg reflectors and an optical cavity between the two distributed Bragg reflectors, and the second-type optical filters include a distributed Bragg reflector and an optical cavity;

[0011] Different optical cavities of different first-type optical filters have different thicknesses, and different optical cavities of different second-type optical filters have different thicknesses.

[0012] Optionally, the size of the optical cavity is consistent with the size of the corresponding pixel circuit.

[0013] Optionally, the number of the first-type optical filters is the same as the number of the second-type optical filters.

[0014] Optionally, the colloidal quantum dot infrared detection unit includes a first electrode, a second electrode, and a colloidal quantum dot layer, the first electrode and the second electrode are oppositely arranged in a plane parallel to the plane on which the readout circuit is located, the colloidal quantum dot layer is located on a side of the first electrode and the second electrode away from the readout circuit, and fills between the first electrode and the second electrode.

[0015] Optionally, the colloidal quantum dot infrared detection unit includes a third electrode, a first-type doped layer, a colloidal quantum dot layer, a second-type doped layer, and a fourth electrode stacked in a direction of the readout circuit pointing to the random optical filter array, the first-type doped layer and the second-type doped layer are one of an N-type doped layer and a P-type doped layer, and are different from each other.

[0016] Optionally, the material of the colloidal quantum dot layer includes one of lead sulfide, lead selenide, lead telluride, cadmium sulfide, cadmium selenide, mercury telluride, mercury selenide, mercury sulfide, silver telluride, silver sulfide, and silver selenide;

[0017] The first electrode and the second electrode are metal electrodes, the third electrode is a metal electrode or a transparent electrode, and the fourth electrode is a transparent electrode; wherein the material of the metal electrode comprises one of platinum, gold, silver, copper, aluminum and chromium, and the material of the transparent electrode comprises one of indium tin oxide and fluorine-doped tin dioxide;

[0018] The material of the N-type doped layer comprises one of bismuth selenide, bismuth sulfide, bismuth telluride, zinc oxide, cadmium selenide, titanium dioxide, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, methyl butyrate, and the same N-type quantum dot as the material of the colloidal quantum dot layer.

[0019] The material of the P-type doped layer comprises one of silver telluride, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, poly 3-hexyl thiophene, 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, polytriarylamine, nickel oxide, zinc telluride, C 60 and the same P-type quantum dot as the material of the colloidal quantum dot layer.

[0020] The present disclosure also provides a preparation method of an infrared hyperspectral imaging detector for forming any of the above infrared hyperspectral imaging detectors; the preparation method of the infrared hyperspectral imaging detector comprises:

[0021] Providing and cleaning a readout circuit; the readout circuit has pixel circuits arranged in an array;

[0022] Preparation of a colloidal quantum dot infrared detection unit on one side of the readout circuit; the colloidal quantum dot infrared detection unit is arranged in an array on one side of the readout circuit;

[0023] Coupling a random optical filter array on the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the random optical filter array comprises optical filters arranged in an array, different optical filters have different light transmission wavelength bands, and the light transmission wavelength band of the optical filter is within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.

[0024] Optionally, the preparation of the colloidal quantum dot infrared detection unit comprises:

[0025] Forming a preset electrode layer on one side of the readout circuit;

[0026] Patterning the preset electrode layer to form a first electrode and a second electrode, the first electrode and the second electrode being oppositely arranged in a plane parallel to the readout circuit;

[0027] A colloidal quantum dot layer is formed on the side of the first electrode and the second electrode away from the readout circuit by spin coating, drop coating, spray coating, blade coating or evaporation film forming method, and the colloidal quantum dot layer also fills between the first electrode and the second electrode;

[0028] Alternatively,

[0029] The preparation of the colloidal quantum dot infrared detection unit comprises:

[0030] A third electrode is formed on the side of the readout circuit;

[0031] A first type of doped layer is formed on the side of the third electrode away from the readout circuit by drop coating, spin coating, spray coating, blade coating or evaporation film forming method;

[0032] A colloidal quantum dot layer is formed on the side of the first type of doped layer away from the third electrode by spin coating, drop coating, spray coating, blade coating or evaporation film forming method;

[0033] A second type of doped layer is formed on the side of the colloidal quantum dot layer away from the first type of doped layer by drop coating, spin coating, spray coating, blade coating or evaporation film forming method;

[0034] A fourth electrode is formed on the side of the second type of doped layer away from the colloidal quantum dot layer by thermal evaporation, magnetron sputtering or atomic layer deposition film forming method.

[0035] Optionally, the coupling random filter array comprises:

[0036] The random filter array is coupled by means of glue curing or welding.

[0037] The present disclosure also provides an imaging method of an infrared hyperspectral imaging detector, which is based on any of the above infrared hyperspectral imaging detectors.

[0038] Compared with the prior art, the technical solutions provided by the present disclosure have the following advantages:

[0039] The infrared hyperspectral imaging detector provided by the present disclosure comprises a readout circuit, a colloidal quantum dot infrared detection unit and a random filter array, wherein the readout circuit has an array of pixel circuits; the colloidal quantum dot infrared detection unit is coupled on one side of the readout circuit; the colloidal quantum dot infrared detection unit is arrayed on one side of the readout circuit; the random filter array is coupled on the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the random filter array comprises an array of filters, different filters have different light transmission wavelength bands, and the light transmission wavelength band of the filter is within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit. In this way, the colloidal quantum dot infrared detection unit can be directly coupled with the area array readout circuit to realize area array infrared imaging, so that real-time imaging can be realized without using scanning or coding, the imaging efficiency is high, the image resolution is high; at the same time, by setting the detection unit as a colloidal quantum dot detection unit, the integration of colloidal quantum dot detection units with different response wavelength bands can be realized, and the colloidal quantum dot can be directly coupled with the readout circuit without using flip-chip coupling mode, so that the cost is low; and there is no flip-chip substrate above the colloidal quantum dot infrared detection unit, so that the filter can be directly coupled to realize hyperspectral detection; at the same time, by directly coupling the filter with the readout circuit coated with colloidal quantum dots, the filter can be selectively transparent, so that there is no need for spectral scanning, the structure of the optical system and the imaging detector is simplified, the hyperspectral image can be directly output, the imaging speed is fast, and real-time imaging can be realized; in addition, the random filter array composed of Fabry-Perot (F-P) filters is used for coding mask, efficient information compression is realized through random spatial-spectral coding, and real-time and high-resolution hyperspectral imaging is realized. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure.

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor.

[0042] Figure 1 A structural schematic diagram of an infrared hyperspectral imaging detector provided by the present disclosure;

[0043] Figure 2 A working principle schematic diagram of a filter in the infrared hyperspectral imaging detector provided by the present disclosure;

[0044] Figure 3A structure schematic diagram of a random filter array in an infrared hyperspectral imaging detector provided by the embodiment of the present disclosure is shown in FIG. 1.

[0045] Figure 4 A structure schematic diagram of a single pixel in an infrared hyperspectral imaging detector provided by the embodiment of the present disclosure is shown in FIG. 2.

[0046] Figure 5 A structure schematic diagram of another single pixel in an infrared hyperspectral imaging detector provided by the embodiment of the present disclosure is shown in FIG. 3.

[0047] Figure 6 A transmittance schematic diagram of a random filter array in an infrared hyperspectral imaging detector provided by the embodiment of the present disclosure is shown in FIG. 4.

[0048] Figure 7 An imaging principle schematic diagram of an infrared hyperspectral imaging detector provided by the embodiment of the present disclosure is shown in FIG. 5.

[0049] Figure 8 A flow schematic diagram of a preparation method of an infrared hyperspectral imaging detector provided by the embodiment of the present disclosure is shown in FIG. 6. DETAILED DESCRIPTION

[0050] In order to more clearly understand the above-mentioned purposes, features and advantages of the present disclosure, the schemes of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0051] In the following description, many specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure can also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some of the embodiments of the present disclosure, not all the embodiments.

[0052] The infrared hyperspectral imaging detector provided by the embodiments of the present disclosure is based on infrared colloidal quantum dots. The colloidal quantum dot infrared detection unit formed based on the infrared colloidal quantum dots can be directly coupled with a silicon-based readout circuit, and a Fabry-Perot filter (F-P filter) array can be directly coupled above the colloidal quantum dot infrared detection unit (i.e., on the light-incident side away from the readout circuit), so as to realize pixel-level filtering. By setting different light transmission wavelength bands of different filters in the random filter array, for example, by designing a first type of F-P filter with top / bottom distributed Bragg reflector (DBR) and a second type of F-P filter with only bottom DBR, and in combination with the differential design of the cavity thickness of the optical cavity, spectral diversity can be realized. The F-P filters are randomly arranged, the transmittance of the F-P filters of each pixel in the random filter array is obtained, the compressed information detected by the infrared hyperspectral detector is decompressed into hyperspectral information through random spatial-spectral coding, the embodiments of the present disclosure can break through the limitations of traditional infrared materials and the limitations of the traditional pixel-level filter method, and real-time hyperspectral imaging with high resolution can be realized.

[0053] Exemplarily, Figure 1 A structural schematic diagram of an infrared hyperspectral imaging detector provided by the embodiments of the present disclosure is shown in FIG. 1. Referring to FIG. 1, Figure 1 The infrared hyperspectral imaging detector 10 includes a readout circuit 11, a colloidal quantum dot infrared detection unit, and a random filter array 13. The readout circuit 11 has an array of pixel circuits, i.e., the readout circuit 11 is a surface array readout circuit. The colloidal quantum dot infrared detection unit is coupled on one side of the readout circuit 11; the colloidal quantum dot infrared detection unit is arrayed on one side of the readout circuit 11, forming an array 12 of colloidal quantum dot infrared detection units corresponding to the surface array readout circuit. The random filter array 13 is coupled on the side of the array 12 of colloidal quantum dot infrared detection units away from the readout circuit 11; the random filter array 13 includes an array of filters (see Figure 3 or Figure 7 ), different filters have different light transmission wavelength bands, and the light transmission wavelength bands of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.

[0054] Exemplarily, Figure 7 A structure of the random filter array shown in FIG. 2, wherein the random filter array includes a plurality of filters with different light transmission wavelength bands, Figure 7 The grid of one color represents one filter, and different filters have different light transmission wavelength bands. In other embodiments, the filters in the random filter array can also be arranged in other manners, which are not limited herein.

[0055] In the infrared hyperspectral imaging detector 10 provided in this embodiment, the colloidal quantum dot infrared detection unit can be directly coupled to the area array readout circuit to achieve area array infrared imaging, thus eliminating the need for scanning or coding, enabling real-time imaging with high imaging efficiency and high image resolution. Simultaneously, by setting the detection unit as a colloidal quantum dot detection unit, the colloidal quantum dots can be directly coupled to the readout circuit without the need for flip-chip bonding, resulting in low cost. Furthermore, since there is no flip-chip bonding substrate above the colloidal quantum dot infrared detection unit, it can be directly coupled to the filter to achieve hyperspectral detection. In addition, by directly coupling the filter to the readout circuit coated with colloidal quantum dots, selective light transmission through the filter can be achieved, eliminating the need for spectral scanning, simplifying the structure of the optical system and imaging detector, and allowing direct output of hyperspectral images with fast imaging speed and real-time imaging. Moreover, by using a random filter array composed of filters for coding masking, efficient information compression is achieved through random spatial-spectral coding, realizing real-time and high-resolution hyperspectral imaging.

[0056] In some embodiments, Figure 1 The readout circuit 11 can be CMOS, TFT or CCD.

[0057] In some embodiments, Figure 2 This is a schematic diagram illustrating the working principle of a filter in an infrared hyperspectral imaging detector provided in this embodiment of the disclosure. Figure 3 This is a schematic diagram of a random filter array in an infrared hyperspectral imaging detector provided in an embodiment of this disclosure. Figure 1 Based on, refer to Figure 2 and Figure 3 The filters 130 in the random filter array 13 may include a first type of filter 1301 and a second type of filter 1302; along the direction of the readout circuit 11 pointing to the random filter array 13 ( Figure 2 and Figure 3 (From bottom to top) The first type of filter 1301 includes two distributed Bragg mirrors arranged opposite each other and an optical cavity 133 located between the two distributed Bragg mirrors. Figure 2 and Figure 3 In the diagram, two distributed Bragg mirrors are shown, with the first mirror 131 and the second mirror 132; the second type of filter 1302 includes a distributed Bragg mirror (i.e., the first mirror 131) and an optical cavity 133; wherein the thickness of the optical cavity 133 of different first type filters 1301 is different, and the thickness of the optical cavity 133 of different second type filters 1302 is different.

[0058] The two oppositely arranged distributed Bragg reflectors have two parallel high reflection mirrors (distributed Bragg reflector, DBR), and the optical filter 130 is located between the two reflection mirrors, thereby forming a Fabry-Perot filter (F-P filter). The incident light is reflected multiple times between the two mirrors, forming a multi-beam interference. When the phase difference of the light in the cavity is an integer multiple of 2π (i.e., the resonance condition is met), the light undergoes constructive interference, and the transmittance is maximum. By adjusting the thickness of the optical cavity, the wavelength of the light with the maximum transmittance can be changed.

[0059] Further, by gradually changing the optical cavity thickness of the different first type filters in the entire random filter array, and gradually changing the optical cavity thickness of the different second type filters, i.e., gradually changing the optical cavity thickness of the filters in the random filter array, and a part of the filters only containing the bottom DBR (for reference Figure 3 ), the spectral transmittance of the different filters in the random filter array can be made different, thereby realizing spectral diversity (for reference Figure 6 ). In the preparation method, the F-P filters with different optical cavity thicknesses and only containing the bottom DBR are used to form the random filter array by means of photolithography and etching, which will be described in detail later.

[0060] In some embodiments, the size of the optical cavity is consistent with the size of the corresponding pixel circuit, i.e., the size is the same within the error tolerance range, so as to realize the pixel-level arrangement of the filter, and then realize the pixel-level filtering based on the random filter array.

[0061] It can be understood that the same size can be the same two-dimensional size in the plane parallel to the readout circuit, for example, both are rectangular, which can have the same length and width, or for example, both are circular, which can have the same diameter, which is not limited here.

[0062] In some embodiments, the number of the first type filters and the number of the second type filters are the same, thereby gradually changing the optical cavity thickness of the filters in the random filter array, and a half of the filters only containing the bottom DBR (for reference Figure 3 ), so as to make the spectral transmittance of the different filters in the random filter array different, thereby realizing spectral diversity.

[0063] In some embodiments, the colloidal quantum dot infrared detection unit can be a photoconductive type detection unit.

[0064] For example, Figure 4 A structure schematic diagram of a single pixel in an infrared hyperspectral imaging detector provided by the embodiments of the present disclosure. Based on Figure 1 , reference is made to Figure 4The single-pixel structure of the infrared hyperspectral imaging detector 10 may include a pixel circuit 110, a colloidal quantum dot infrared detection unit 120, and a filter 130; wherein, the colloidal quantum dot infrared detection unit 120 includes a first electrode 121, a second electrode 122, and a colloidal quantum dot layer 123. The first electrode 121 and the second electrode 122 are arranged opposite to each other in a plane parallel to the readout circuit. The colloidal quantum dot layer 123 is located on the side of the first electrode 121 and the second electrode 122 away from the readout circuit and fills the space between the first electrode 121 and the second electrode 122.

[0065] In some embodiments, the colloidal quantum dot infrared detection unit may be a photovoltaic detection unit.

[0066] For example, Figure 5 This is a schematic diagram of another single pixel structure in an infrared hyperspectral imaging detector provided in an embodiment of this disclosure. Figure 1 Based on, refer to Figure 5 The single-pixel structure of the infrared hyperspectral imaging detector 10 may include a pixel circuit 110, a colloidal quantum dot infrared detection unit 120, and a filter 130; wherein, the colloidal quantum dot infrared detection unit 120 includes a direction along the readout circuit 11 pointing to the random filter array 13 ( Figure 4 The third electrode 124, the first type doped layer 125, the colloidal quantum dot layer 123, the second type doped layer 127, and the fourth electrode 128 are stacked from bottom to top. The first type doped layer 125 and the second type doped layer 127 are either N-type doped layers or P-type doped layers, and they are different. For example, the first type doped layer 125 is an N-type doped layer and the second type doped layer 127 is a P-type doped layer; or, the first type doped layer 125 is a P-type doped layer and the second type doped layer 127 is an N-type doped layer, which is not limited here.

[0067] Below Figure 4 and Figure 5 Based on this, the optional materials for each layer in the colloidal quantum dot infrared detection unit 120 are described by way of example.

[0068] In some embodiments, the colloidal quantum dot layer (i.e. Figure 4 The colloidal quantum dot layer 123 shown, or Figure 5 The colloidal quantum dot layer 123 shown includes infrared colloidal quantum dots, the material of which is one of lead sulfide (PbS), lead selenide (PbSe), lead telluride (PbTe), cadmium sulfide (CdS), cadmium selenide (CdSe), mercuric telluride (HgTe), mercuric selenide (HgSe), mercuric sulfide (HgS), silver telluride (Ag2Te), silver sulfide (Ag2S), and silver selenide (Ag2Se).

[0069] In some embodiments, Figure 4 In this configuration, the first electrode 121 and the second electrode 122 can be metal electrodes; Figure 5 In the process, the third electrode 124 is a metal electrode or a transparent electrode, and the fourth electrode 128 is a transparent electrode.

[0070] The metal electrode can be made of platinum, gold, silver, copper, aluminum, or chromium, while the transparent electrode can be made of indium tin oxide (ITO) or fluorine-doped tin dioxide (FTO).

[0071] In some embodiments, Figure 5 Based on this, the materials for the N-type doped layer include bismuth selenide (Bi2Se3), bismuth sulfide (Bi2S3), bismuth telluride (Bi2Te3), zinc oxide (ZnO), cadmium selenide (CdSe), titanium dioxide (TiO2), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), methyl butyrate (PCBM), and one of the N-type quantum dots that are the same as the materials for the colloidal quantum dot layer; the materials for the P-type doped layer include silver telluride (Ag2Te), poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS), poly(3-hexylthiophene) (P3HT), 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (spiro-OMeTAD), polytriarylamine (PTAA), and nickel oxide (NiO2). x ), zinc telluride (ZnTe), C 60 And one of the P-type quantum dots that are the same as the colloidal quantum dot layer material.

[0072] In other embodiments, the layers of the colloidal quantum dot infrared detection unit 120 may also be made of other materials known to those skilled in the art, and are not limited herein.

[0073] The imaging principle and effect of the infrared hyperspectral imaging detector provided in the embodiments of this disclosure will be described by way of example.

[0074] Specifically, the random filter array is directly coupled to the side of the array opposite to the area array readout circuit composed of colloidal quantum dot infrared detection units, so that a filter with a specific transmission band is directly integrated on each pixel, as referenced. Figure 7 Different colors represent filters with different light transmission bands. After forming a randomly arranged FP filter array, before coupling the random filter array to the detector, the transmittance of each filter in the random filter array in each band is measured according to the response band of the colloidal quantum dot detection.

[0075] For example, the detector's response wavelength is 1000nm~2500nm (in reality, depending on the type of colloidal quantum dots, the response wavelength ranges from 800-15000nm), within the response wavelength range... For interval ( The transmittance of the filter array can be measured (10-100nm). , The array size of the readout circuit (e.g., 128×128, 320×256, 640×512, 1280×1024 pixel array) represents the transmittance. After measuring the transmittance, the random filter array is coupled to the area array readout circuit with colloidal quantum dot infrared detection unit by means of glue curing or welding.

[0076] When the information of the imaged object is captured by the detector, the information of the imaged object includes spatial information. and spectral information Spatial and spectral information can be jointly represented as a three-dimensional data matrix. (e.g., 640×512×20 band), due to each pixel on the detector Spectral transmittance of the filter on They are all different (reference) Figure 6 Therefore, the light of different wavelengths in each pixel will be summed to form a monochrome compressed image. Specifically, it can be expressed as:

[0077]

[0078] in, The number of bands is specified, with a minimum value of 4; then, an iterative algorithm (such as gradient descent, Newton's method, conjugate gradient method, Jacobi iteration method, Gauss-Seidel iteration method, ISTA, FISTA, or TwIST) is used to solve for the band number. To achieve hyperspectral imaging, see the flowchart. Figure 7 .

[0079] This disclosure also provides an imaging method for an infrared hyperspectral imaging detector. This imaging method is based on any of the infrared hyperspectral imaging detectors provided in the above embodiments, and can perform real-time imaging with high resolution and richer imaging details.

[0080] This disclosure also provides a method for fabricating an infrared hyperspectral imaging detector, used to form any of the infrared hyperspectral imaging detectors provided in the above embodiments.

[0081] For example, Figure 8 This is a schematic flowchart illustrating a method for fabricating an infrared hyperspectral imaging detector according to an embodiment of this disclosure. (Reference)Figure 8 The preparation method of the infrared hyperspectral imaging detector can include the following steps.

[0082] S21, providing and cleaning the readout circuit.

[0083] The readout circuit has an array of pixel circuits; the readout circuit can be cleaned with cleaning solutions such as acetone, isopropyl alcohol, alcohol, and deionized water to remove dirt and impurities on the surface of the readout circuit, thereby improving the preparation quality of the colloidal quantum dot infrared detection unit and the overall performance of the infrared hyperspectral imaging detector.

[0084] S22, preparing a colloidal quantum dot infrared detection unit on one side of the readout circuit.

[0085] The colloidal quantum dot infrared detection unit is arrayed on one side of the readout circuit.

[0086] In some embodiments, the colloidal quantum dot infrared detection unit is a light guide type infrared detection unit, and the preparation of the colloidal quantum dot infrared detection unit can specifically include:

[0087] forming a pre-electrode layer on one side of the readout circuit, the pre-electrode layer being an integral electrode layer;

[0088] performing a patterning process on the pre-electrode layer to form a first electrode and a second electrode, the first electrode and the second electrode being oppositely arranged in a plane parallel to the readout circuit;

[0089] forming a colloidal quantum dot layer on the side of the first electrode and the second electrode away from the readout circuit by using a film forming method such as spin coating, drop coating, spraying, blade coating, or evaporation, the colloidal quantum dot layer also being filled between the first electrode and the second electrode.

[0090] In some embodiments, the colloidal quantum dot infrared detection unit is a photovoltaic type infrared detection unit, and the preparation of the colloidal quantum dot infrared detection unit can specifically include:

[0091] forming a third electrode on one side of the readout circuit;

[0092] forming a first type of doped layer on the side of the third electrode away from the readout circuit by using a film forming method such as drop coating, spin coating, spraying, blade coating, or evaporation;

[0093] forming a colloidal quantum dot layer on the side of the first type of doped layer away from the third electrode by using a film forming method such as spin coating, drop coating, spraying, blade coating, or evaporation;

[0094] forming a second type of doped layer on the side of the colloidal quantum dot layer away from the first type of doped layer by using a film forming method such as drop coating, spin coating, spraying, blade coating, or evaporation;

[0095] The fourth electrode is formed on the side of the second type of doped layer away from the colloidal quantum dot layer by a film forming method of thermal evaporation, magnetron sputtering or atomic layer deposition.

[0096] The first electrode and the second electrode can be metal electrodes, the third electrode can be a metal electrode or a transparent electrode, and the fourth electrode can be a transparent electrode.

[0097] In some embodiments, the preparation of the metal electrode can specifically include: forming a whole layer of electrode on one side of the readout circuit, and then modifying the whole layer of electrode by a photolithography process of one of ultraviolet lithography, laser direct writing and electron beam exposure (one of dry etching, wet etching and stripping) to obtain an electrode layer after patterning, wherein the thickness of the electrode is 5-100 nanometers.

[0098] For the light guide type infrared detection unit, the infrared colloidal quantum dots are prepared on the electrode layer by a film forming method of one of spin coating, drop coating, spraying, blade coating and evaporation, and the film thickness of the infrared colloidal quantum dots after film forming is 100-1000 nanometers.

[0099] For the photovoltaic type infrared detection unit, after the electrode layer is formed, the material of the N-type doped layer is formed on the electrode layer by a film forming method of one of drop coating, spin coating, spraying, blade coating and evaporation, and the thickness of the N-type doped layer is 50-200 nanometers; then, the infrared colloidal quantum dots (i.e. intrinsic colloidal quantum dots) are formed on the N-type doped layer by a film forming method of one of spin coating, drop coating, spraying, blade coating and evaporation, and the thickness of the colloidal quantum dot layer is 300-1000 nanometers; then, the material of the P-type doped layer is formed on the colloidal quantum dot layer by a film forming method of one of drop coating, spin coating, spraying, blade coating and evaporation, and the thickness of the P-type doped layer is 50-200 nanometers; then, the material of the fourth electrode (i.e. transparent electrode) is formed on the P-type doped layer by a film forming method of thermal evaporation, magnetron sputtering or atomic layer deposition, and the thickness of the fourth electrode is 5-100 nanometers.

[0100] S23, coupling a random optical filter array on the side of the colloidal quantum dot infrared detection unit away from the readout circuit.

[0101] The random optical filter array includes arrayed optical filters, different optical filters have different light transmission wavelength bands, and the light transmission wavelength band of the optical filter is within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.

[0102] In some embodiments, coupling the random optical filter array includes:

[0103] The random optical filter array is coupled by glue curing or welding.

[0104] In some embodiments, the preparation steps of the random optical filter array can specifically include:

[0105] First, deposit silicon (Si) and silicon dioxide (SiO2) alternately by chemical vapor deposition (CVD), physical vapor deposition (PVD) or atomic layer deposition (ALD) on a clean sapphire substrate to form a first distributed Bragg reflector with a total thickness of 200 nm to 2000 nm.

[0106] Second, deposit 1-2 microns of silicon dioxide (SiO2) as an optical cavity by chemical vapor deposition (CVD), physical vapor deposition (PVD) or atomic layer deposition (ALD); and use grayscale mask or multiple exposure (one of UV lithography, laser direct writing and electron beam exposure) and etching process (dry etching or wet etching) to create differences in the thickness of the entire surface optical cavity, forming multiple optical cavity arrays with different thicknesses. The size of each optical cavity should be consistent with the size of the corresponding coupled readout circuit pixel (for example, if the pixel size of the coupled readout circuit is 15 μm x 15 μm, the size of the corresponding single optical cavity should also be 15 μm x 15 μm), thus achieving pixel-level filtering.

[0107] Third, deposit silicon (Si) and silicon dioxide (SiO2) alternately by chemical vapor deposition (CVD), physical vapor deposition (PVD) or atomic layer deposition (ALD) on a portion of the optical cavity array (for example, half) to form a second distributed Bragg reflector with a total thickness of 200 nm to 2000 nm.

[0108] Fourth, use photolithography (one of UV lithography, laser direct writing and electron beam exposure) to make the size of the optical filter consistent with the size of the corresponding coupled readout circuit pixel (for example, if the pixel size of the coupled readout circuit is 15 μm x 15 μm, the size of the corresponding single optical cavity should also be 15 μm x 15 μm); form independent filtering units (the size of the optical filter array should be consistent with the size of the readout circuit to be coupled).

[0109] In the preparation method of the infrared hyperspectral imaging detector provided by the embodiments of the present disclosure, the colloidal quantum dot layer can be formed by one of the film forming methods of spin coating, drop coating, spraying, blade coating and evaporation, so that the array of the colloidal quantum dot infrared detection unit is directly coupled with the area array readout circuit, the detected optical signal is converted into an electrical signal and output. In the preparation of the colloidal quantum dot infrared detection unit using infrared colloidal quantum dots as photosensitive materials, the band range of the infrared colloidal quantum dots can be accurately adjusted by changing the reaction temperature, reaction time and reactant ratio during the synthesis of the infrared colloidal quantum dots, so as to widen the detection band of the detector. For example, the size of the infrared colloidal quantum dots can be 2-8 nanometers, and the corresponding wavelength response range is 1000-3000 nanometers. At the same time, the synthesis process of the infrared colloidal quantum dots is simple, and the liquid material can be converted into a solid functionalized film by a low-cost liquid-phase processing technology, without the need for expensive flip-chip bonding, molecular beam epitaxy and other processes, which greatly reduces the material processing cost and the cost of the detector.

[0110] It should be noted that, in this document, the terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Also, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0111] The above description is only a specific embodiment of the present disclosure, enabling those skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An infrared hyperspectral imaging detector, characterized by, The application relates to a high-spectrum imaging device. The device comprises: a readout circuit with pixel circuits arranged in an array; a colloidal quantum dot infrared detection unit coupled to one side of the readout circuit; the colloidal quantum dot infrared detection unit is arranged in an array on one side of the readout circuit; a random filter array coupled to the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the random filter array comprises filters arranged in an array, the light transmission wavelength bands of different filters are different, and the light transmission wavelength bands of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit; wherein the transmittance of each filter in the random filter array at each wavelength band is determined based on the response wavelength band of the colloidal quantum dot detection in the colloidal quantum dot infrared detection unit; the random filter array composed of the filters is used for encoding mask, high-efficiency information compression is realized through random space-spectrum coding, and real-time hyperspectral imaging is realized. The filters comprise first-type filters and second-type filters. In the direction of the readout circuit pointing to the random filter array, the first-type filters comprise two oppositely arranged distributed Bragg reflectors and an optical cavity between the two distributed Bragg reflectors, and the second-type filters comprise one distributed Bragg reflector and an optical cavity.

2. The infrared hyperspectral imaging detector of claim 1, wherein, The thicknesses of the optical cavities of different first-type filters are different, and the thicknesses of the optical cavities of different second-type filters are different.

3. The infrared hyperspectral imaging detector of claim 1, wherein, The size of the optical cavity is consistent with the size of the corresponding pixel circuit.

4. The infrared hyperspectral imaging detector of claim 1, wherein, The number of the first-type filters is the same as the number of the second-type filters. The colloidal quantum dot infrared detection unit comprises a first electrode, a second electrode and a colloidal quantum dot layer, the first electrode and the second electrode are oppositely arranged in a plane parallel to the plane where the readout circuit is located, the colloidal quantum dot layer is located on the side of the first electrode and the second electrode away from the readout circuit and is filled between the first electrode and the second electrode. Alternatively, 5. The infrared hyperspectral imaging detector of claim 4, wherein, The colloidal quantum dot infrared detection unit comprises a third electrode, a first-type doped layer, a colloidal quantum dot layer, a second-type doped layer and a fourth electrode which are arranged in a stack in the direction of the readout circuit pointing to the random filter array, the first-type doped layer and the second-type doped layer are one of N-type doped layers and P-type doped layers, and the two are different. The material of the colloidal quantum dot layer comprises one of lead sulfide, lead selenide, lead telluride, cadmium sulfide, cadmium selenide, mercury telluride, mercury selenide, mercury sulfide, silver telluride, silver sulfide and silver selenide; The first electrode and the second electrode are metal electrodes, the third electrode is a metal electrode or a transparent electrode, and the fourth electrode is a transparent electrode; wherein the material of the metal electrode comprises one of platinum, gold, silver, copper, aluminum and chromium, and the material of the transparent electrode comprises one of indium tin oxide and fluorine-doped tin dioxide. The material of the N-type doped layer includes one of bismuth selenide, bismuth sulfide, bismuth telluride, zinc oxide, cadmium selenide, titanium dioxide, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, methyl butyrate, and an N-type quantum dot same as the material of the colloidal quantum dot layer; The material of the P-type doped layer includes silver telluride, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, poly 3-hexyl thiophene, 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, polytriarylamine, nickel oxide, zinc telluride, C 60 and one of the P-type quantum dots which are the same as the material of the colloidal quantum dot layer.

6. A method of making an infrared hyperspectral imaging detector, comprising: The infrared hyperspectral imaging detector according to any one of claims 1-5; The preparation method of the infrared hyperspectral imaging detector comprises: providing and cleaning a readout circuit; the readout circuit has pixel circuits arranged in an array; preparing a colloidal quantum dot infrared detection unit on one side of the readout circuit; the colloidal quantum dot infrared detection unit is arranged in an array on one side of the readout circuit; coupling a random optical filter array on the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the random optical filter array comprises optical filters arranged in an array, different optical filters have different light transmission wavelength bands, and the light transmission wavelength band of the optical filter is within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.

7. The method of claim 6, wherein the infrared hyper-spectral imaging probe is prepared by, The preparation of the colloidal quantum dot infrared detection unit comprises: forming a preset electrode layer on one side of the readout circuit; performing a patterning process on the preset electrode layer to form a first electrode and a second electrode, the first electrode and the second electrode are oppositely arranged in a plane parallel to the readout circuit; forming a colloidal quantum dot layer on the side of the first electrode and the second electrode away from the readout circuit by using a film forming method of spin coating, drop coating, spraying, blade coating or evaporation, and the colloidal quantum dot layer also fills between the first electrode and the second electrode; Alternatively, The preparation of the colloidal quantum dot infrared detection unit comprises: forming a third electrode on one side of the readout circuit; forming a first type doped layer on the side of the third electrode away from the readout circuit by using a film forming method of drop coating, spin coating, spraying, blade coating or evaporation; forming a colloidal quantum dot layer on the side of the first type doped layer away from the third electrode by using a film forming method of spin coating, drop coating, spraying, blade coating or evaporation; forming a second type doped layer on the side of the colloidal quantum dot layer away from the first type doped layer by using a film forming method of drop coating, spin coating, spraying, blade coating or evaporation; forming a fourth electrode on the side of the second type doped layer away from the colloidal quantum dot layer by using a film forming method of thermal evaporation, magnetron sputtering or atomic layer deposition.

8. The method of claim 6, wherein the infrared hyper-spectral imaging detector is prepared by, The coupling of the random optical filter array on the side of the colloidal quantum dot infrared detection unit away from the readout circuit comprises: coupling the random optical filter array on the side of the colloidal quantum dot infrared detection unit away from the readout circuit by using a method of glue curing or welding.

9. An imaging method of an infrared hyperspectral imaging detector, characterized by, The infrared hyperspectral imaging detector according to any one of claims 1-5 is executed.

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