Infrared hyperspectral imaging detector and preparation method and imaging method thereof
By employing a colloidal quantum dot infrared detection unit directly coupled to an area array readout circuit in a hyperspectral imaging detector, and using a Fabry-Perot filter array, the real-time performance and resolution issues of infrared band imaging were resolved, achieving efficient infrared hyperspectral imaging.
Patent Information
- Application Number
- CN202511262374.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-05
- Publication Date
- 2025-11-04
AI Technical Summary
Existing hyperspectral imaging detectors cannot achieve area array imaging in the infrared band. They have long imaging times, low resolution, and complex optical systems, making real-time imaging impossible.
By directly coupling the colloidal quantum dot infrared detection unit with the area array readout circuit and combining it with the Fabry-Perot filter array, pixel-level filtering is achieved, and hyperspectral images are directly output, simplifying the optical system.
It achieves real-time and high-resolution area array infrared imaging, reduces costs, simplifies the optical system structure, and improves imaging speed.
Smart Images
Figure CN120897536A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of infrared detection, in particular to an infrared hyperspectral imaging detector and a preparation method and imaging method thereof. BACKGROUND
[0002] The hyperspectral imaging detector is an advanced imaging device capable of capturing the continuous narrow-band spectral information of a target object. Compared with the traditional imaging detector, the hyperspectral imaging detector can perceive continuous fine spectral information and distinguish the slight spectral differences that cannot be distinguished by the traditional imaging detector. The hyperspectral imaging detector can identify specific materials through spectral feature matching and realize hyperspectral imaging through algorithm fusion, and can analyze the proportions of each component. The hyperspectral imaging 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 silicon material, which is usually applied to the visible light band and cannot detect the infrared band. The detector extended to the infrared band is usually a single-point imaging system, which needs to rely on scanning imaging or coded imaging to realize hyperspectral imaging, and the imaging time is long and the resolution is low; second, the traditional bulk material realizing infrared response is limited by flip-chip technology and cannot be directly coupled with the filter, and usually needs a front optical system for light splitting, which increases the complexity of the optical system; third, the hyperspectral imaging detector based on light splitting needs to obtain data through spatial or spectral scanning, and has low frame rate and slow speed, and cannot realize real-time imaging. 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 having an array of pixel circuits;
[0007] A colloidal quantum dot infrared detection unit coupled to one side of the readout circuit; the colloidal quantum dot infrared detection unit is arrayed on one side of the readout circuit;
[0008] A filter array coupled to the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the filter array comprises an array of repeating units, each repeating unit comprising an array of filters, different filters in the same repeating unit having different light transmission wavelengths, and the light transmission wavelengths of the filters being within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.
[0009] Optionally, along a direction of the readout circuit pointing to the filter array, the filter comprises a first mirror, a second mirror, and an optical cavity between the first mirror and the second mirror.
[0010] In the same repeating unit, the thickness of the optical cavity of different filters is different.
[0011] Optionally, the size of the optical cavity is consistent with the size of the corresponding coupled pixel circuit.
[0012] Optionally, the thickness of the optical cavity is 500 nanometers to 2 microns.
[0013] Optionally, 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.
[0014] Optionally, 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 stacked along a direction of the readout circuit pointing to the filter array, the first type doped layer and the second type doped layer are one of N-type doped layer and P-type doped layer, and are different from each other.
[0015] Optionally, 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.
[0016] 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.
[0017] 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 an N-type quantum dot same as the material of the colloidal quantum dot layer.
[0018] 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 is the same as the material of the colloidal quantum dot layer.
[0019] 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:
[0020] providing and cleaning a readout circuit; the readout circuit has pixel circuits arranged in an array;
[0021] 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;
[0022] coupling a filter array on the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the filter array comprises repeating units arranged in an array, each of the repeating units comprises filters arranged in an array, the light transmission wavelengths of the filters in the same repeating unit are different, and the light transmission wavelengths of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.
[0023] Optionally, the preparation of the colloidal quantum dot infrared detection unit comprises:
[0024] forming a preset electrode layer on one side of the readout circuit;
[0025] 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;
[0026] 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, spray coating, blade coating or evaporation, and the colloidal quantum dot layer also fills between the first electrode and the second electrode;
[0027] Alternatively,
[0028] the preparation of the colloidal quantum dot infrared detection unit comprises:
[0029] forming a third electrode on one side of the readout circuit;
[0030] 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, spray coating, blade coating or evaporation;
[0031] 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;
[0032] 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;
[0033] 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.
[0034] Optionally, the coupling filter array comprises:
[0035] The filter array is coupled by means of glue curing or welding.
[0036] The present disclosure also provides an imaging method of an infrared hyperspectral imaging detector, which is executed based on any of the above infrared hyperspectral imaging detectors.
[0037] Compared with the prior art, the technical solutions provided by the present disclosure have the following advantages:
[0038] The infrared hyperspectral imaging detector provided by the present disclosure comprises a readout circuit, a colloidal quantum dot infrared detection unit and a filter array; 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, and the colloidal quantum dot infrared detection unit is arrayed on one side of the readout circuit; the filter array is coupled on the side of the colloidal quantum dot infrared detection unit away from the readout circuit, and the filter array comprises an array of repeating units, each repeating unit comprises an array of filters, different filters in the same repeating unit have different light transmission wavelengths, and the light transmission wavelengths of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit. Thus, 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 the need for scanning or coding, the imaging efficiency is high, and the image resolution is high; at the same time, by setting the detection unit as a colloidal quantum dot detection unit, the colloidal quantum dot can be directly coupled with the readout circuit without the need for a 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; in addition, by directly coupling the filter with the readout circuit coated with colloidal quantum dots, selective light transmission can be realized based on the filter, so that there is no need for spectral scanning, the structure of the optical system and the imaging detector is simplified, and the hyperspectral image can be directly output, so that the imaging speed is fast and real-time imaging can be realized. BRIEF DESCRIPTION OF DRAWINGS
[0039] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the present disclosure and, together with the description, further serve to explain the principles of the present disclosure.
[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the accompanying drawings required by the embodiments or the prior art description will be briefly introduced as follows. Obviously, those skilled in the art can obtain other drawings according to these drawings without any creative effort.
[0041] Figure 1 A structural schematic diagram of an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown in FIG. 1.
[0042] Figure 2 A working principle schematic diagram of a filter in an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown in FIG. 2.
[0043] Figure 3 A structural schematic diagram of a single pixel in an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown in FIG. 3.
[0044] Figure 4 A structural schematic diagram of another single pixel in an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown in FIG. 4.
[0045] Figure 5 A transmittance schematic diagram of a filter array in an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown in FIG. 5.
[0046] Figure 6 A hyperspectral imaging principle schematic diagram of an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown in FIG. 6.
[0047] Figure 7 A spectral response schematic diagram of infrared colloidal quantum dots of different sizes provided by an embodiment of the present disclosure is shown in FIG. 7.
[0048] Figure 8 A hyperspectral imaging effect schematic diagram provided by an embodiment of the present disclosure is shown in FIG. 8.
[0049] Figure 9 A Figure 8 A magnification effect schematic diagram of images of various channels is shown in FIG. 10.
[0050] Figure 10 A flowchart of a preparation method of an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown in FIG. 11. DETAILED DESCRIPTION
[0051] In order to enable a more clear understanding of 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.
[0052] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present disclosure, but the present disclosure can also be implemented in other manners different from those described herein; obviously, the embodiments described in the specification are only a part of the embodiments of the present disclosure, and not all the embodiments.
[0053] 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 the readout circuit based on silicon, and the array of Fabry-Perot filters (F-P filter) can be directly coupled above the colloidal quantum dot infrared detection unit (i.e., the light-in side away from the readout circuit), so as to realize pixel-level filtering. Based on this, according to the filter array, the information of each spectrum can be extracted, and a separate spectral image can be constructed, and real-time hyperspectral imaging can be realized by using image fusion technology.
[0054] 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 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 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 filter array 13 includes an array of repeating units (see Figure 6 ), and each repeating unit includes an array of filters. The light transmission wavelengths of different filters in the same repeating unit are different, and the light transmission wavelengths of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.
[0055] Exemplarily, Figure 6 The filter array shown in FIG. 1 includes 3 rows and 3 columns of repeating units, and each repeating unit includes 3 rows and 3 columns of filters. Specifically, a grid of one color represents one filter, and the light transmission wavelengths of different filters are different. In other embodiments, the repeating units in the filter array can also be arranged in other manners, and the filters in the repeating units can also be arranged in other manners, which are not limited herein.
[0056] The infrared hyperspectral imaging detector 10 provided by the embodiments of the present disclosure can realize direct coupling of the colloidal quantum dot infrared detection unit and the surface array readout circuit, realize surface array infrared imaging, and thus can realize real-time imaging without using scanning or coding, has high imaging efficiency and high image resolution; meanwhile, by setting the detection unit as a colloidal quantum dot detection unit, the colloidal quantum dot can be directly coupled with the readout circuit without using flip-chip coupling, and thus has low cost; and the colloidal quantum dot infrared detection unit has no flip-chip substrate on the top, can be directly coupled with a filter, and realizes hyperspectral detection; in addition, by directly coupling the filter and the readout circuit coated with colloidal quantum dots, selective light transmission can be realized based on the filter, and thus there is no need to perform light splitting scanning, the structure of the optical system and the imaging detector is simplified, and the hyperspectral image can be directly output, the imaging speed is fast, and real-time imaging can be realized.
[0057] In some embodiments, on the basis of Figure 1 , the readout circuit 11 can be CMOS, TFT or CCD.
[0058] In some embodiments, on the basis of Figure 2 , the filter array 13 provided by the infrared hyperspectral imaging detector of the embodiments of the present disclosure is a Fabry-Perot filter array. Figure 1 On the basis of Figure 2 , along the direction in which the readout circuit 11 points to the filter array 13 (the direction from bottom to top in Figure 2 , the filter 130 includes a first mirror 131, a second mirror 132 and an optical cavity 133 between the first mirror 131 and the second mirror 132, thereby constituting a Fabry-Perot filter; the thicknesses of the optical cavities 133 of different filters 130 in the same repeating unit are different.
[0059] In the filter 130, the first mirror 131 and the second mirror 132 have two parallel high reflection mirror surfaces, and the filter 130 is composed of the two parallel high reflection mirror surfaces (distributed Bragg mirror, DBM) and the optical cavity 133. The incident light is reflected multiple times between the two mirror surfaces, forming multiple-beam interference. When the phase difference of the light in the cavity for one round trip is an integer multiple of 2π (i.e., the resonance condition is met), the light experiences constructive interference, the transmittance is maximum, and by adjusting the thickness H0 of the optical cavity, the wavelength of the light with the maximum transmittance can be changed.
[0060] In the preparation method, the F-P filter with different thicknesses of optical cavities is used to form the filter array by means of photolithography, which will be described in detail hereinafter. Figure 6 The transmittance diagram of the filter array shown can refer to Figure 5 in combination with Figure 2 , Figure 6 and Figure 5The wide-spectrum incident light can form narrow-band emergent light with different peak wavelengths after passing through the filter array.
[0061] 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 an error tolerance, so that the pixel-level arrangement of the filter is realized, and then the pixel-level filtering is realized based on the filter array.
[0062] It can be understood that the same size can be the same two-dimensional size in a plane parallel to the plane where the readout circuit is located. For example, in the case of a rectangle, the same length and width can be used; or for example, in the case of a circle, the same diameter can be used, which is not limited here.
[0063] In some embodiments, the thickness of the optical cavity is 500 nanometers to 2 microns. For example, the thickness of the optical cavity can be 500 nanometers, 2 microns, 800 nanometers, 1 micron, 1.5 microns, 1.3 microns, 1.8 microns, 600 nanometers to 900 nanometers, 1.2 microns to 1.4 microns, or other thickness values or thickness range values, which need to meet the light transmission requirements of the filter array.
[0064] In some embodiments, the colloidal quantum dot infrared detection unit can be a photoconductive type detection unit.
[0065] For example, Figure 3 A structure diagram of a single pixel of an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown. Based on the structure diagram of the single pixel of the infrared hyperspectral imaging detector 10 shown in Figure 1 , referring to Figure 3 , the single pixel structure of the infrared hyperspectral imaging detector 10 can 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 oppositely arranged in a plane parallel to the plane where the readout circuit is located, 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 is filled between the first electrode 121 and the second electrode 122.
[0066] In some embodiments, the colloidal quantum dot infrared detection unit can be a photovoltaic type detection unit.
[0067] For example, Figure 4 Another structure diagram of a single pixel of an infrared hyperspectral imaging detector provided by an embodiment of the present disclosure is shown. Based on the structure diagram of the single pixel of the infrared hyperspectral imaging detector 10 shown in Figure 1 , referring 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 direction along the readout circuit 11 pointing to the 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.
[0068] Below Figure 3 and Figure 4 Based on this, the optional materials for each layer in the colloidal quantum dot infrared detection unit 120 are described by way of example.
[0069] In some embodiments, the colloidal quantum dot layer (i.e. Figure 3 The colloidal quantum dot layer 123 shown, or Figure 4 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).
[0070] In some embodiments, Figure 3 In this configuration, the first electrode 121 and the second electrode 122 can be metal electrodes; Figure 4 In the process, the third electrode 124 is a metal electrode or a transparent electrode, and the fourth electrode 128 is a transparent electrode.
[0071] 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).
[0072] In some embodiments, Figure 4On the basis of the above, the material of the N-type doped layer includes one of 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 the same N-type quantum dot as the material of the colloidal quantum dot layer; the material of the P-type doped layer includes one of silver telluride (Ag2Te), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), poly-3-hexylthiophene (P3HT), 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD), polytriazylamine (PTAA), nickel oxide (NiO x ), zinc telluride (ZnTe), C 60 , and the same P-type quantum dot as the material of the colloidal quantum dot layer.
[0073] In other embodiments, other materials known to those skilled in the art can also be used for each layer in the colloidal quantum dot infrared detection unit 120, which are not limited herein.
[0074] The imaging principle and effect of the infrared hyperspectral imaging detector provided by the embodiments of the present disclosure are exemplarily described below.
[0075] Specifically, the filter array is directly coupled on the side of the array formed by the colloidal quantum dot infrared detection unit away from the side-on array readout circuit, so that a specific light transmission waveband filter is directly integrated on each pixel. Figure 6 Different colors represent filters of different light transmission wavelengths. Figure 6 In the above, only nine kinds of filters are taken as an example to show the filter array, and in actual application, the light transmission wavelengths of the filter array can also be four, sixteen or other quantities, which are not limited herein. The filters are arranged in a certain rule. Figure 6 In the above, only a mosaic arrangement is taken as an example, and in actual application, other periodic distribution or random arrangement can be used, which are not limited herein. Figure 6 In the above, N x and N y represent the array scale of the filter and the corresponding readout circuit. Exemplarily, the array can be 128x128, 320x256, 640x512, 1280x1024 or other arranged arrays, which are not limited herein.
[0076] The filter of a specific light transmission wavelength only allows light of a specific wavelength to pass through, the specific wavelength of light passing through the filter can be detected by the colloidal quantum dot infrared detection unit below the filter, the colloidal quantum dot infrared detection unit converts the light signal into an electrical signal and transmits it to the pixel circuit, and only the signal corresponding to the specific wavelength is output for each pixel. The output voltage g(x, y) of a single pixel (x, y) at each exposure can be represented as:
[0077] g(x,y)=f(x,y,λ)*A(x,y,λ)*S(λ)
[0078] Wherein, f(x,y,λ) is the real spectral information of the object, A(x,y,λ) is the transmittance function of the filter of the pixel (for reference Figure 5 ), S(λ) is the spectral response of the colloidal quantum dot infrared detector, and the colloidal quantum dots can realize the response to different wavebands by adjusting the synthesis temperature and reaction time, so as to realize the coupling of the filter of different filter wavebands, so that the best working waveband of the quantum dot infrared detector is consistent with the filter waveband (for reference Figure 7 , wherein the spectral response curves of four different sizes of infrared colloidal quantum dots are shown), through the distribution of the filter, the pixel output voltage corresponding to the same wavelength filter is extracted, and the difference between adjacent pixels is obtained N w spectrum pictures (N w is the number of filter channels), each picture reflects the spectral information of a single waveband of the imaged object, and then the image fusion technology is used to fuse N w pictures into 1 picture, realizing real-time hyperspectral imaging, as shown in Figure 6 and Figure 8 (combined with Figure 9 ). Compared with the traditional imaging detector which can only reflect the size of the gray value, the hyperspectral imaging detector obtains a more detailed picture, which can reflect the information of each waveband of the imaged object, as shown in Figure 8 (combined with Figure 9 ). For example, based on Figure 6 , combined with Figure 8 and Figure 9 , the number of channels N w may be 9, for example Figure 9The channels 1-9 shown in the figure can be a 1472nm filter channel, a 1407nm filter channel, a 1342nm filter channel, a 1655nm filter channel, a 1595nm filter channel, a 1535nm filter channel, a 1280nm filter channel, a 1217nm filter channel, and a 1160nm filter channel respectively. The image of each channel reflects the spectral information of the imaging object at the corresponding single waveband. In each single-channel image, the horizontal and vertical coordinates represent pixel coordinates, and different gray scales in the legend represent the relative light intensity.
[0079] The present disclosure also provides an imaging method of the infrared hyperspectral imaging detector. The imaging method is executed based on any of the infrared hyperspectral imaging detectors provided in the above embodiments, can realize real-time imaging, and has more detailed imaging.
[0080] The present disclosure also provides a preparation method of the infrared hyperspectral imaging detector, which is used to form any of the infrared hyperspectral imaging detectors provided in the above embodiments.
[0081] For example, Figure 10 A flowchart of the preparation method of the infrared hyperspectral imaging detector provided in the present disclosure is shown in FIG. 6. Referring to FIG. 6, Figure 10 The preparation method of the infrared hyperspectral imaging detector can include the following steps.
[0082] S21, providing and cleaning a readout circuit.
[0083] The readout circuit has an arrayed pixel circuit. The readout circuit can be cleaned by using a cleaning solution such as acetone, isopropyl alcohol, alcohol, and deionized water, so as to remove dirt and impurities on the surface of the readout circuit, improve the preparation quality of the colloidal quantum dot infrared detection unit, and improve 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. The preparation of the colloidal quantum dot infrared detection unit can specifically include:
[0087] A preset electrode layer is formed on one side of the readout circuit. The preset electrode layer is an integral electrode layer.
[0088] The preset electrode layer is subjected to a patterning process 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.
[0089] On the side of the first electrode and the second electrode away from the readout circuit, a colloidal quantum dot layer is formed by spin coating, drop coating, spray coating, blade coating or evaporation film forming mode, and the colloidal quantum dot layer is also 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] A third electrode is formed on the side of the readout circuit;
[0092] On the side of the third electrode away from the readout circuit, a first type of doped layer is formed by drop coating, spin coating, spray coating, blade coating or evaporation film forming mode;
[0093] On the side of the first type of doped layer away from the third electrode, a colloidal quantum dot layer is formed by spin coating, drop coating, spray coating, blade coating or evaporation film forming mode;
[0094] On the side of the colloidal quantum dot layer away from the first type of doped layer, a second type of doped layer is formed by drop coating, spin coating, spray coating, blade coating or evaporation film forming mode;
[0095] On the side of the second type of doped layer away from the colloidal quantum dot layer, a fourth electrode is formed by thermal evaporation, magnetron sputtering, atomic layer deposition film forming mode.
[0096] Among them, 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 metal electrode is prepared, which can specifically include: forming a whole layer of electrode on the side of the readout circuit, and then modifying the whole layer of electrode by one of the photolithography processes of ultraviolet lithography, laser direct writing and electron beam exposure (one of dry etching, wet etching and stripping), to obtain the electrode layer after patterning, wherein the thickness of the electrode is 5 nanometers to 100 nanometers.
[0098] For the light guide type infrared detection unit, the infrared colloidal quantum dots are prepared on the electrode layer by one of the film forming modes of spin coating, drop coating, spray coating, blade coating and evaporation, and the film layer thickness of the infrared colloidal quantum dots after film forming is 100 nanometers to 1000 nanometers.
[0099] For the photovoltaic infrared detection unit, after forming the electrode layer, the material of the N-type doped layer is formed on the electrode layer by one of drop coating, spin coating, spraying, blade coating and evaporation, and the thickness of the N-type doped layer is 50-200 nm; then, the infrared colloidal quantum dots (i.e. intrinsic colloidal quantum dots) are formed on the N-type doped layer by one of spin coating, drop coating, spraying, blade coating and evaporation, and the thickness of the colloidal quantum dot layer is 300-1000 nm; then, the material of the P-type doped layer is formed on the colloidal quantum dot layer by one of drop coating, spin coating, spraying, blade coating and evaporation, and the thickness of the P-type doped layer is 50-200 nm; then, the material of the fourth electrode (i.e. transparent electrode) is formed on the P-type doped layer by one of thermal evaporation, magnetron sputtering or atomic layer deposition, and the thickness of the fourth electrode is 5-100 nm.
[0100] S23, coupling the filter array to the side of the colloidal quantum dot infrared detection unit away from the readout circuit.
[0101] The filter array includes array-arranged repeating units, and each repeating unit includes array-arranged filters. Different filters in the same repeating unit have different light transmission wavelengths, and the light transmission wavelengths of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.
[0102] In some embodiments, the filter array is coupled by:
[0103] The filter array is coupled by means of glue curing or welding.
[0104] In some embodiments, the preparation steps of the filter array can specifically include:
[0105] First, 100-500 nm of silicon (Si) and 100-500 nm of silicon dioxide (SiO2) are respectively deposited on a clean sapphire substrate by chemical vapor deposition (CVD), physical vapor deposition (PVD) or atomic layer deposition to form a first distributed Bragg reflector.
[0106] Second step, 1-2 microns of silicon dioxide (SiO2) is deposited as optical cavity by chemical vapor deposition (CVD), physical vapor deposition (PVD) or atomic layer deposition (ALD) method; and through multi-step photolithography (including one of ultraviolet photolithography, laser direct writing and electron beam exposure) and etching process (dry etching or wet etching), the whole surface optical cavity thickness is different, the optical cavity thickness is 500nm-2um, thus forming a plurality of optical cavity arrays with different thicknesses, the size of each optical cavity is consistent with the size of the corresponding coupled readout circuit pixel (for example, if the pixel size in the coupled readout circuit is 15μm×15μm, the size of the corresponding single optical cavity should also be 15μm×15μm), so as to realize pixel-level light filtering.
[0107] Third step, 100-500 nanometers of silicon (Si) and 100-500 nanometers of silicon dioxide (SiO2) are respectively deposited on the optical cavity array by chemical vapor deposition (CVD), physical vapor deposition (PVD) or atomic layer deposition (ALD) method, to form a second distributed Bragg reflector.
[0108] The preparation method of the infrared hyperspectral imaging detector provided by the embodiments of the present disclosure can form a colloidal quantum dot layer by one of spin coating, drop coating, spraying, blade coating and evaporation, so as to directly couple the array of the colloidal quantum dot infrared detection unit with the area array readout circuit, convert the detected optical signal into an electrical signal and output. The infrared colloidal quantum dots are used as photosensitive materials to prepare the colloidal quantum dot infrared detection unit, and by changing the reaction temperature, reaction time, reactant ratio and other parameters in the synthesis process of the infrared colloidal quantum dots, the wavelength range of the infrared colloidal quantum dots can be accurately adjusted, and the detection wavelength range of the detector can be widened. 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 functional 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.
[0109] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0110] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. An infrared hyperspectral imaging detector, characterized in that, include: The readout circuit has an array of pixel circuits; A colloidal quantum dot infrared detection unit is coupled to one side of the readout circuit; the colloidal quantum dot infrared detection units are arranged in an array on one side of the readout circuit. A filter array is coupled to the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the filter array includes repeating units arranged in an array, each repeating unit including filters arranged in an array, the transmission wavelengths of different filters in the same repeating unit are different, and the transmission wavelengths of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.
2. The infrared hyperspectral imaging detector according to claim 1, characterized in that, Along the direction of the readout circuit pointing to the filter array, the filter includes a first mirror, a second mirror, and an optical cavity located between the first mirror and the second mirror; Within the same repeating unit, the optical cavities of different filters have different thicknesses.
3. The infrared hyperspectral imaging detector according to claim 2, characterized in that, The size of the optical cavity is the same as the size of the corresponding coupled pixel circuit.
4. The infrared hyperspectral imaging detector according to claim 2, characterized in that, The thickness of the optical cavity is 500 nanometers to 2 micrometers.
5. The infrared hyperspectral imaging detector according to claim 1, characterized in that, 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 arranged opposite each other in a plane parallel to the readout circuit. The colloidal quantum dot layer is located on the side of the first electrode and the second electrode away from the readout circuit and fills the space between the first electrode and the second electrode. or, 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 along the direction of the readout circuit toward the filter array. The first type doped layer and the second type doped layer are respectively one of an N-type doped layer and a P-type doped layer, and the two are different.
6. The infrared hyperspectral imaging detector according to claim 5, characterized in that, The material of the colloidal quantum dot layer includes one of lead sulfide, lead selenide, lead telluride, cadmium sulfide, cadmium selenide, mercuric telluride, mercuric selenide, mercuric 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 includes one of platinum, gold, silver, copper, aluminum and chromium, and the material of the transparent electrode includes 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 N-type quantum dots that are the same as the material of the colloidal quantum dot layer. The materials of the P-type doped layer include silver telluride, poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, poly3-hexylthiophene, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, polytriarylamine, nickel oxide, zinc telluride, and C. 60 And one of the P-type quantum dots that are the same as the colloidal quantum dot layer material.
7. A method for fabricating an infrared hyperspectral imaging detector, characterized in that, Used to form the infrared hyperspectral imaging detector according to any one of claims 1-6; The method for fabricating the infrared hyperspectral imaging detector includes: Provide and clean the readout circuit; the readout circuit has an array of pixel circuits; A colloidal quantum dot infrared detection unit is fabricated 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; A filter array is coupled to the side of the colloidal quantum dot infrared detection unit away from the readout circuit; the filter array includes repeating units arranged in an array, each repeating unit including filters arranged in an array, the transmission wavelengths of different filters in the same repeating unit are different, and the transmission wavelengths of the filters are within the detection wavelength range of the corresponding colloidal quantum dot infrared detection unit.
8. The method for fabricating an infrared hyperspectral imaging detector according to claim 7, characterized in that, The preparation of the colloidal quantum dot infrared detection unit includes: A preset electrode layer is formed on one side of the readout circuit; The preset electrode layer is patterned to form a first electrode and a second electrode, which are arranged opposite to each other in a plane parallel to the readout circuit. On the side of the first electrode and the second electrode away from the readout circuit, a colloidal quantum dot layer is formed by a film-forming method such as spin coating, drop coating, spray coating, scraping coating or evaporation, and the colloidal quantum dot layer is also filled between the first electrode and the second electrode. or, The preparation of the colloidal quantum dot infrared detection unit includes: A third electrode is formed on one side of the readout circuit; On the side of the third electrode opposite to the readout circuit, a first type of doped layer is formed by film formation methods such as drop coating, spin coating, spray coating, scraping coating or evaporation. On the side of the first type of doped layer away from the third electrode, a colloidal quantum dot layer is formed by a film-forming method such as spin coating, drop coating, spray coating, blade coating or evaporation. On the side of the colloidal quantum dot layer opposite to the first type of doped layer, a second type of doped layer is formed by film formation methods such as drop coating, spin coating, spray coating, blade coating or evaporation; On the side of the second type of doped layer away from the colloidal quantum dot layer, a fourth electrode is formed using thermal evaporation, magnetron sputtering, and atomic layer deposition.
9. The method for fabricating an infrared hyperspectral imaging detector according to claim 7, characterized in that, The filter array coupled to the side of the colloidal quantum dot infrared detection unit opposite to the readout circuit includes: On the side of the colloidal quantum dot infrared detection unit away from the readout circuit, the filter array is coupled by means of adhesive curing or welding.
10. An imaging method for an infrared hyperspectral imaging detector, characterized in that, Performed based on the infrared hyperspectral imaging detector according to any one of claims 1-6.