Infrared detector, and system

Abstract

The present disclosure relates to an infrared detector, and a system. The infrared detector comprises: a substrate; and a quantum dot detection structure, wherein the quantum dot detection structure is located on one side of the substrate; the quantum dot detection structure comprises at least two infrared photosensitive layers, which are sequentially stacked on one side of the substrate, and infrared bands to which the infrared photosensitive layers respond are different; and the quantum dot detection structure is used for outputting corresponding electrical signals to the substrate in response to infrared light signals of different bands. In this way, a quantum dot detection structure is configured to comprise at least two infrared photosensitive layers, and infrared bands to which the infrared photosensitive layers respond are different, such that the infrared detector can simultaneously capture a plurality of pieces of infrared band information, thereby further realizing wide-spectrum detection and imaging in the infrared bands.

Description

Infrared detectors and systems

[0001] This disclosure claims priority to Chinese Patent Application No. 202411527897.3, filed with the Chinese Patent Office on October 30, 2024, entitled "Infrared Detector and System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of infrared detection technology, and in particular to an infrared detector and system. Background Technology

[0003] In the field of infrared imaging, infrared detectors have evolved from single-unit to multi-unit, and then from multi-unit to focal plane, forming various types of infrared detectors. These include infrared detectors that integrate flexible curved substrates with traditional flexible sensing functional units. By bending or folding, the planar array is shaped into a hemispherical structure and combined with a single lens. The curvature of the lens focal plane is matched to correct spherical aberration, achieving high-resolution imaging with a single lens. This demonstrates the great development potential and space for flexible infrared focal plane detectors.

[0004] However, current infrared detectors, such as flexible infrared focal plane detectors, can only detect a limited range of infrared bands and can only collect information from a single infrared band. They cannot collect information from multiple infrared bands simultaneously, which makes it difficult to achieve broadband infrared detection and imaging, thus limiting the development of infrared detectors. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this disclosure provides an infrared detector and system.

[0006] This disclosure provides an infrared detector, including: a substrate; and a quantum dot detection structure, the quantum dot detection structure being located on one side of the substrate; the quantum dot detection structure includes at least two infrared photosensitive layers sequentially stacked on one side of the substrate, each of the infrared photosensitive layers responding to a different infrared band;

[0007] The quantum dot detection structure is used to output corresponding electrical signals to the substrate in response to infrared light signals of different wavelengths.

[0008] In some embodiments, each of the infrared photosensitive layers forms a PN junction, and two adjacent infrared photosensitive layers form two reverse PN junctions.

[0009] In some embodiments, the quantum dot detection structure includes: a plurality of first electrodes, the plurality of first electrodes being disposed at intervals on one side of the substrate; a first infrared photosensitive layer located on the side of the first electrodes opposite to the substrate; a second infrared photosensitive layer located on the side of the first infrared photosensitive layer opposite to the first electrodes; and a second electrode located on the side of the second infrared photosensitive layer opposite to the first infrared photosensitive layer.

[0010] In some embodiments, the first infrared photosensitive layer includes a first N-type quantum dot layer, a first intrinsic quantum dot layer, and a first P-type quantum dot layer stacked sequentially along the direction from the first electrode to the second electrode; the second infrared photosensitive layer includes a second P-type quantum dot layer, a second intrinsic quantum dot layer, and a second N-type quantum dot layer stacked sequentially along the direction from the first electrode to the second electrode.

[0011] In some embodiments, the first P-type quantum dot layer is reused as the second P-type quantum dot layer.

[0012] In some embodiments, the response bands of the first intrinsic quantum dot layer and the second intrinsic quantum dot layer are any two of short-wave infrared, mid-wave infrared, and long-wave infrared.

[0013] This disclosure also provides an infrared detection system, including a power supply and any of the infrared detectors described above;

[0014] The power supply is connected to the infrared detector and is used to provide an activation voltage to the infrared detector.

[0015] In some embodiments, one end of the power supply is connected to the substrate of the infrared detector, and the other end is connected to the second electrode of the infrared detector.

[0016] In some embodiments, the power supply includes a first power supply and a second power supply; the first power supply is used to provide a positive voltage, and the second power supply is used to provide a negative voltage.

[0017] In some embodiments, a lens is also included; the lens is located on the light-incident surface side of the infrared detector.

[0018] The technical solution provided in this disclosure has the following advantages compared with the prior art: The infrared detector provided in this disclosure includes: a substrate; and a quantum dot detection structure, the quantum dot detection structure being located on one side of the substrate; the quantum dot detection structure includes at least two infrared photosensitive layers stacked sequentially on one side of the substrate, each infrared photosensitive layer responding to a different infrared band; the quantum dot detection structure is used to output corresponding electrical signals to the substrate in response to infrared light signals of different bands. Thus, by setting the quantum dot detection structure to include at least two infrared photosensitive layers, and each infrared photosensitive layer responding to a different infrared band, the infrared detector can simultaneously acquire information from multiple infrared bands, further realizing broadband infrared detection and imaging. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 is a schematic diagram of the structure of an infrared detector provided in an embodiment of this disclosure;

[0022] Figure 2 is a schematic diagram of another infrared detector provided in an embodiment of this disclosure;

[0023] Figure 3 is a schematic diagram of the principle structure of an infrared detector provided in an embodiment of this disclosure;

[0024] Figure 4 is a schematic diagram of the principle structure of another infrared detector provided in an embodiment of this disclosure;

[0025] Figure 5 is a schematic diagram of an infrared detection system provided in an embodiment of this disclosure.

[0026] Among them, 01 is the infrared photosensitive layer; 110 is the substrate; 120 is the quantum dot detection structure; 121 is the first electrode; 122 is the first infrared photosensitive layer; 1221 is the first N-type quantum dot layer; 1222 is the first intrinsic quantum dot layer; 1223 is the first P-type quantum dot layer; 123 is the second infrared photosensitive layer; 1231 is the second P-type quantum dot layer; 1232 is the second intrinsic quantum dot layer; 1233 is the second N-type quantum dot layer; 124 is the second electrode; 320 is the first power supply; and 220 is the second power supply. Detailed Implementation

[0027] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0028] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0029] The infrared detector and system provided in the embodiments of this disclosure will be described exemplarily below with reference to the accompanying drawings.

[0030] Figure 1 is a schematic diagram of an infrared detector provided in an embodiment of this disclosure. Referring to Figure 1, the infrared detector includes: a substrate 110; and a quantum dot detection structure 120, which is located on one side of the substrate 110. The quantum dot detection structure 120 includes at least two infrared photosensitive layers 01 stacked sequentially on one side of the substrate 110, each infrared photosensitive layer 01 responding to a different infrared band. The quantum dot detection structure 120 is used to output corresponding electrical signals to the substrate 110 in response to infrared light signals of different bands.

[0031] In some embodiments, substrate 110 is a substrate for carrying quantum dot detection structure 120. Exemplarily, substrate 110 may be a silicon-based readout circuit substrate or other types of substrates for detection imaging, which are not limited herein.

[0032] In some embodiments, the infrared photosensitive layer 01 comprises colloidal quantum dot material. Colloidal quantum dots (or simply quantum dots) are semiconductor nanocrystals whose properties can be directly controlled through the quantum confinement effect. For example, for the infrared band, by controlling the reaction conditions in the preparation process, the response band of quantum dots can reach the short-wave infrared, mid-wave infrared, long-wave infrared, and terahertz range. Here, the infrared band of response of each infrared photosensitive layer 01 is not limited.

[0033] It should be noted that existing infrared detectors use bulk infrared materials such as indium gallium arsenide (InGaAs), indium antimonide (InSb), and mercury cadmium telluride (HgCdTe). Due to the requirements of the crystal structure, these materials require high-quality single-crystal substrates. Moreover, photodetectors based on these bulk materials are difficult to integrate with related silicon-based readout circuits. They often require flip-chip bonding technology using molecular beam epitaxy to form infrared detectors, which increases the manufacturing cost of infrared detectors and limits their application areas.

[0034] The emergence of colloidal quantum dots has solved the problems faced by existing bulk infrared materials. Specifically, colloidal quantum dots have advantages such as tunable optical properties, liquid-phase processing capability, and silicon-based compatibility. They can be manipulated using low-cost and easily scalable colloidal technologies. For example, liquid-phase colloidal quantum dots can be processed onto silicon-based readout circuits by spin coating, spraying, or photolithography to obtain infrared devices. The operation is simple, suitable for large-scale preparation and mass production, and eliminates the need for expensive flip-chip bonding, molecular beam epitaxy, and other processes, greatly reducing material processing costs.

[0035] Specifically, after external infrared light is incident on the quantum dot detection structure 120, the infrared photosensitive layer 01 in the quantum dot detection structure 120 performs photoelectric response based on the incident infrared light, that is, converts the infrared light signal of a certain band into the corresponding electrical signal and outputs it to the substrate 110 so that subsequent related circuits can perform detection and imaging through the electrical signal.

[0036] For example, the quantum dot detection structure 120 may include two infrared photosensitive layers 01, three infrared photosensitive layers 01 or other numbers of infrared photosensitive layers 01, which can be set according to actual detection needs and are not limited here.

[0037] The infrared detector provided in this embodiment includes: a substrate 110; and a quantum dot detection structure 120, which is located on one side of the substrate 110. The quantum dot detection structure 120 includes at least two infrared photosensitive layers 01 stacked sequentially on one side of the substrate 110. Each infrared photosensitive layer 01 responds to a different infrared band, and the quantum dot detection structure 120 outputs a corresponding electrical signal to the substrate 110 in response to infrared light signals of different bands. Thus, by setting the quantum dot detection structure 120 to include at least two infrared photosensitive layers 01, and each infrared photosensitive layer 01 responds to a different infrared band, the infrared detector can simultaneously acquire information from multiple infrared bands, further realizing broadband infrared detection and imaging.

[0038] In some embodiments, referring to FIG1, each infrared photosensitive layer 01 constitutes a PN junction, and two adjacent infrared photosensitive layers 01 constitute two reverse PN junctions.

[0039] In some embodiments, a PN junction comprises an N-type semiconductor and a P-type semiconductor, and the boundary or interface between these two semiconductor materials is called a PN junction. It is understood that free electrons diffuse from the N-type semiconductor region (N-region) to the P-type semiconductor region (P-region), and holes diffuse from the P-region to the N-region. After this diffusion, the region near the PN junction contains only immobile charged ions, and this region is called the intermediate charge region. A built-in electric field is formed in the space charge region, with its direction pointing from the N-region to the P-region.

[0040] In this context, two reversed PN junctions refer to two PN junctions placed on one side of the substrate. Although their built-in electric fields both point from the N-region to the P-region, they point in opposite directions relative to the same reference direction. For example, a P-type semiconductor layer can be placed on the surface of substrate 110, and two N-type semiconductor layers and one P-type semiconductor layer can be sequentially placed upwards to obtain two adjacent PN junctions. The built-in electric field of the lower PN junction points upwards, while the built-in electric field of the upper PN junction points downwards, and their directions are opposite, thus forming two reversed PN junctions. Alternatively, an N-type semiconductor layer can be placed on the surface of substrate 110, and two P-type semiconductor layers and one N-type semiconductor layer can be sequentially placed upwards to similarly obtain two reversed PN junctions, which will not be elaborated further here.

[0041] In some embodiments, FIG2 is a schematic diagram of another infrared detector structure provided in the present disclosure. Based on FIG1, referring to FIG2, the quantum dot detection structure 120 includes: a plurality of first electrodes 121, which are spaced apart on one side of the substrate 110; a first infrared photosensitive layer 122 located on the side of the first electrodes 121 away from the substrate 110; a second infrared photosensitive layer 123 located on the side of the first infrared photosensitive layer 122 away from the first electrodes 121; and a second electrode 124 located on the side of the second infrared photosensitive layer 123 away from the first infrared photosensitive layer 122.

[0042] In some embodiments, the first electrode 121 is the bottom electrode of the quantum dot detection structure 120, used to collect electrons or holes generated by the quantum dot detection structure 120 based on photoelectric response. Exemplarily, the first electrode 121 may be one or more of indium tin oxide (ITO), fluorine-doped zinc oxide (FTO), gold, silver, and nickel-chromium alloy. It may be deposited first by physical vapor deposition (PVD) such as thermal evaporation or magnetron sputtering, and then etched by photolithography and etching to form the first electrode 121 arranged in an array. Other conductive materials and fabrication processes may also be used to form the first electrode 121, which is not limited here.

[0043] It is understandable that by setting the first electrodes 121 at intervals on one side of the substrate 110, the number of first electrodes 121 is increased, making the first electrodes 121 arranged in an array on the substrate surface. This allows electrons generated by the photoelectric response to be received by the first electrodes 121 at each location. Furthermore, the infrared information collected by the infrared detector becomes more refined, increasing the device's resolution, making infrared imaging clearer, and improving the quality of broadband infrared detection imaging. Preferably, each electrode 121 can correspond one-to-one with a pixel area of ​​the substrate 110 to collect information from each pixel area, effectively improving the resolution of the infrared detector.

[0044] In some embodiments, the second electrode 124 is the top electrode of the quantum dot detection structure 120, used to collect electrons or holes generated by the quantum dot detection structure 120 based on photoelectric response. Exemplarily, the second electrode 124 may be made of gold or silver, and may be prepared by thermal evaporation or electron beam evaporation, and the materials and processes used for its preparation are not limited herein.

[0045] For example, the thickness of the first electrode 121 can be 90nm to 110nm, and the thickness of the second electrode 124 can be 5nm to 20nm. It should be noted that by setting the thickness of the second electrode 124 to the above range, it is possible to ensure that the second electrode 124 has good transmittance to external infrared light, avoids it from blocking external infrared light too much and hindering the infrared detector from absorbing infrared light, thereby improving the performance of the infrared detector.

[0046] For example, Figure 3 is a schematic diagram of the principle structure of an infrared detector provided in an embodiment of the present disclosure, and Figure 4 is a schematic diagram of the principle structure of another infrared detector provided in an embodiment of the present disclosure. Referring to Figures 2 to 4, the substrate 110, the first electrode 121, the first infrared photosensitive layer 122, and the second electrode 124 functionally form an infrared detector for detecting a first wavelength band (see Figure 3), and the substrate 110, the first electrode 121, the second infrared photosensitive layer 123, and the second electrode 124 functionally form an infrared detector for detecting a second wavelength band (see Figure 4), and the first and second wavelength bands are different infrared wavelength bands.

[0047] In some embodiments, by setting a first infrared photosensitive layer 122 and a second infrared photosensitive layer 123, the infrared detector includes two PN junctions in opposite directions. When an activation voltage is subsequently applied to control the operation of the infrared detector using a power supply, the direction of the applied electric field is consistent with the direction of the built-in electric field in the PN junction, that is, providing positive and negative voltages. Thus, the operation of infrared detectors of different bands can be controlled according to the different directions of the applied electric field, so as to simultaneously output information of two infrared bands. However, when the two (or more) PN junctions are in the same direction, it is difficult to achieve the operation of infrared detectors of different bands using the same applied electric field. The control principle of the applied electric field on the infrared detector will be described in detail later.

[0048] Thus, the embodiments of this disclosure can simplify the overall structure of the device and save on the manufacturing cost while ensuring that the infrared detector collects information from different infrared bands. In addition, when an activation voltage is applied to it by a power supply, infrared detectors of different bands can be controlled to work together in a simple and convenient way.

[0049] In some embodiments, referring to Figures 2 to 4, the first infrared photosensitive layer 122 includes a first N-type quantum dot layer 1221, a first intrinsic quantum dot layer 1222, and a first P-type quantum dot layer 1223 sequentially stacked along the direction from the first electrode 121 to the second electrode 124; the second infrared photosensitive layer 123 includes a second P-type quantum dot layer 1231, a second intrinsic quantum dot layer 1232, and a second N-type quantum dot layer 1233 sequentially stacked along the direction from the first electrode 121 to the second electrode 124.

[0050] In some embodiments, the first N-type quantum dot layer 1221 and the second N-type quantum dot layer 1233 are both N-type semiconductors, and the first P-type quantum dot layer 1223 and the second P-type quantum dot layer 1231 are both P-type semiconductors.

[0051] For example, taking the orientation and structure shown in Figure 2 as an example, multiple first electrodes 121 are spaced apart in the upper plane of the substrate 110. A first N-type quantum dot layer 1221 fills and covers the gaps between the multiple first electrodes 121. The first N-type quantum dot layer 1221, the first intrinsic quantum dot layer 1222, and the first P-type quantum dot layer 1223 constitute the lower PN junction, and the second P-type quantum dot layer 1231, the second intrinsic quantum dot layer 1232, and the second N-type quantum dot layer 1233 constitute the upper PN junction. In this way, a photovoltaic infrared detector is obtained, which can detect information in two infrared bands.

[0052] In some embodiments, the first intrinsic quantum dot layer 1222 and the second intrinsic quantum dot layer 1232 use infrared colloidal quantum dot materials as photosensitive materials. Each absorbs infrared light in different wavelength bands and generates corresponding electrical signals based on the photoelectric response. Exemplarily, the quantum dots in the first intrinsic quantum dot layer 1222 and the second intrinsic quantum dot layer are one or more of intrinsic quantum dots such as mercuric selenide (HgSe), mercuric cadmium telluride (HgCdTe), silver sulfide (Ag₂S), lead sulfide (PbS), lead selenide (PbSe), mercuric telluride (HgTe), cadmium selenide (CdSe), silver telluride (Ag₂Te), and silver selenide (Ag₂Se). By controlling the synthesis time and temperature of the aforementioned quantum dots, the spectral range of the quantum dot response can be precisely controlled, and the reaction conditions in the preparation process of the relevant quantum dots can be adjusted according to actual detection requirements. In this way, it is possible to detect different infrared bands, which has the advantage of a wide detection band. In addition, quantum dots have high sensitivity, and infrared detectors made of quantum dots have strong light response and good detection performance.

[0053] For example, the preparation methods of the first intrinsic quantum dot layer 1222 and the second intrinsic quantum dot layer 1232 include, but are not limited to, spin coating, spray coating, drop coating, etc., and their thickness can be 200nm to 1000nm, which is not limited here.

[0054] For example, the first N-type quantum dot layer 1221 and the second N-type quantum dot layer 1233 may include one or more of N-type quantum dots such as bismuth selenide (Bi2Se3), bismuth sulfide (Bi2S3), bismuth telluride (Bi2Te3), zinc oxide (ZnO), cadmium selenide (CdSe), or intrinsic quantum dots. The first P-type quantum dot layer 1223 and the second P-type quantum dot layer 1231 may include one or more of poly(3-hexylthiophene) (P3HT), poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS), 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (spiro-OMeTAD), polytriarylamine (PTAA), or intrinsic quantum dots. They can be prepared by spin coating, spraying, physical vapor deposition (PVD), or chemical vapor deposition (CVD) to achieve higher uniformity.

[0055] The infrared detector of this embodiment includes a first infrared photosensitive layer 122 comprising a first N-type quantum dot layer 1221, a first intrinsic quantum dot layer 1222, and a first P-type quantum dot layer 1223, and a second infrared photosensitive layer 123 comprising a second P-type quantum dot layer 1231, a second intrinsic quantum dot layer 1232, and a second N-type quantum dot layer 1233. The first P-type quantum dot layer 1223 and the second P-type quantum dot layer 1231 can separate the first intrinsic quantum dot layer 1222 and the second intrinsic quantum dot layer 1232, so as to collect the charge carriers in the lower PN junction and the upper PN junction respectively. This avoids the problem of direct contact between the first intrinsic quantum dot layer 1222 and the second intrinsic quantum dot layer 1232, which would cause carrier interference between them.

[0056] In addition, in practical applications, compared with P-type quantum dots, N-type quantum dots are easier to couple with the substrate and also have higher chemical and optical stability. They can maintain their optical and electrical properties over a wide temperature and pH range. Therefore, in this embodiment, the relevant N-type quantum dot layer, namely the first N-type quantum dot layer 1221, is disposed on one side of the substrate 110, which can achieve better coupling with the substrate 110, improve the stability of the infrared detector, and thus the device has a higher signal-to-noise ratio and better imaging quality.

[0057] In some embodiments, referring to FIG2, the first P-type quantum dot layer 1223 is reused as a second P-type quantum dot layer 1231.

[0058] Specifically, taking the orientation and structure of Figure 2 as an example, after external infrared light shines on the infrared detector, the first infrared photosensitive layer 122 and the second infrared photosensitive layer 123 perform photoelectric response to infrared light signals of different wavelengths, generating photogenerated carriers. Among them, the holes generated by the first intrinsic quantum dot layer 1222 reach the vicinity of the lower edge of the first P-type quantum dot layer 1223, and the holes generated by the second intrinsic quantum dot layer 1232 reach the vicinity of the upper edge of the first P-type quantum dot layer 1223, without generating carrier interference.

[0059] It is understandable that holes and electrons are transported in opposite directions: electrons generated in the first intrinsic quantum dot layer 1222 reach the first N-type quantum dot layer 1221, and electrons generated in the second intrinsic quantum dot layer 1232 reach the second N-type quantum dot layer 1233.

[0060] In this embodiment of the present disclosure, by reusing the first P-type quantum dot layer 1223 as the second P-type quantum dot layer 1231, the number of film layers in the infrared detector can be reduced, thereby reducing the overall volume of the infrared detector and simplifying the fabrication process of the infrared detector. Thus, the miniaturization design of the infrared detector is realized, the fabrication efficiency is improved, and the overall application cost is saved.

[0061] In some embodiments, referring to FIG2, the response band of the first intrinsic quantum dot layer 1222 and the response band of the second intrinsic quantum dot layer 1232 are any two of short-wave infrared, mid-wave infrared and long-wave infrared.

[0062] For example, the response band of the first intrinsic quantum dot layer 1222 may be short-wave infrared, and the intrinsic quantum dots it includes are short-wave quantum dots. The response band of the second intrinsic quantum dot layer 1232 may be mid-wave infrared, and the intrinsic quantum dots it includes are long-wave quantum dots. Alternatively, the response band of the first intrinsic quantum dot layer 1222 may be mid-wave infrared, and the response band of the second intrinsic quantum dot layer 1232 may be long-wave infrared. The band can be set according to the actual detection requirements of this embodiment of the present disclosure, and is not limited here.

[0063] Based on the above embodiments, this disclosure also provides an infrared detection system, including a power supply and any of the infrared detectors provided in the above embodiments.

[0064] The power supply is connected to the infrared detector and is used to provide the activation voltage for the infrared detector.

[0065] Specifically, if the infrared detector includes a PN junction, the built-in electric field of the PN junction can be further enhanced by providing an activation voltage through a power supply. This increases the speed at which electron-hole pairs dissociate into free electrons and holes, as well as the transmission efficiency of electrons and holes. Consequently, the current saturation increases, improving the response speed of the infrared detector and making it more sensitive.

[0066] In addition, since the PN junction has a built-in electric field, the power supply only needs to provide a small activation voltage to drive the infrared detector, which reduces the power consumption of the infrared detection system.

[0067] In some embodiments, one end of the power supply is connected to the base of the infrared detector, and the other end is connected to the second electrode of the infrared detector.

[0068] Specifically, by connecting the base and second electrode of the infrared detector to a power source, a circuit is formed between the infrared detector and the power source. This allows electrons generated by the infrared photosensitive layer to be received by the silicon-based readout circuit of the base along the circuit, thereby enabling broadband infrared detection and imaging.

[0069] In some embodiments, FIG5 is a schematic diagram of an infrared detection system provided in an embodiment of the present disclosure. Referring to FIG3 to FIG5, the power supply includes a first power supply 210 and a second power supply 220; the first power supply 210 is used to provide a positive voltage, and the second power supply 220 is used to provide a negative voltage.

[0070] In some embodiments, positive and negative voltages are used to describe different connection relationships between the positive and negative terminals of the power supply and the infrared detector. For example, taking the orientation and structure of FIG5 as an example, the positive terminal of the first power supply 210 is connected to the second electrode 124 of the infrared detector, and the negative terminal of the first power supply 210 is connected to the substrate 110 of the infrared detector. The voltage it provides can be represented as a positive voltage, and the built-in electric field of the second infrared photosensitive layer 123 is in the same direction as the applied electric field of the first power supply 210. Correspondingly, the positive terminal of the second power supply 220 is connected to the substrate 110 of the infrared detector, and the negative terminal of the second power supply 220 is connected to the second electrode 124 of the infrared detector. The voltage it provides can be represented as a negative voltage, and the built-in electric field of the first infrared photosensitive layer 122 is in the same direction as the applied electric field of the second power supply 220.

[0071] In some embodiments, referring to Figures 3 and 4, when the direction of the applied electric field is consistent with the direction of the built-in electric field in the first infrared photosensitive layer 122, it is equivalent to driving the infrared detector (see Figure 3) used to detect the first band to work, thereby collecting the first band information; when the direction of the applied electric field is consistent with the direction of the built-in electric field in the second infrared photosensitive layer 123, it is equivalent to driving the infrared detector (see Figure 4) used to detect the second band to work, thereby collecting the second band information.

[0072] In this way, by controlling infrared detectors of different bands to work together through external electric fields in different directions, the infrared detector provided in this embodiment can collect information of multiple infrared bands, increasing the detectable infrared bands, thereby realizing broadband infrared detection and imaging, and broadening the application range of infrared detectors.

[0073] In some embodiments, continuing to refer to FIG5, the infrared detection system further includes a control module (not shown in the figure), a first switch S1 and a second switch S2; the first switch S1 is connected between the first power supply 210 and the infrared detector, and the second switch S2 is connected between the second power supply 220 and the infrared detector; both the first switch S1 and the second switch S2 are connected to the control module.

[0074] In some embodiments, the control module is used to control the on / off states of the first switch S1 and the second switch S2. Specifically, when the first switch S1 and the second switch S2 are controlled by the control module to be closed, the circuit between the first power supply 210 and the infrared detector, and the circuit between the second power supply 220 and the infrared detector are connected, so as to provide the required voltage to the infrared detector; conversely, when the first switch S1 and the second switch S2 are controlled by the control module to be open, the circuit between the first power supply 210 and the infrared detector, and the circuit between the second power supply 220 and the infrared detector are open, so that there is no external electric field on the infrared detector.

[0075] For example, the control module may be a microcontroller, a programmable logic controller, or other components with control functions, and is not limited thereto.

[0076] In this way, by using the control module to control the on / off state of the first switch S1 and the second switch S2, the required voltage can be provided to the infrared detector in a timely manner without manual operation, thus improving the convenience of operation.

[0077] In some embodiments, the infrared detection system further includes a lens (not shown); the lens is located on the light-incident surface of the infrared detector.

[0078] Preferably, the substrate of the infrared detector is a flexible curved substrate, and correspondingly, the lens is set as a single lens. It is understood that an infrared detector with a flexible curved substrate is usually called a flexible infrared focal plane detector. Exemplarily, the material used to prepare the flexible curved substrate can be polydimethylsiloxane, polyimide, or other flexible materials. Furthermore, liquid quantum dot materials can be converted into solid functionalized thin films through low-cost liquid-phase processing technology, which can be directly coupled to the silicon-based readout circuit of the flexible curved substrate. This eliminates the need for expensive flip-chip bonding, molecular beam epitaxy, and other processes, greatly reducing material processing costs.

[0079] It should be noted that when a single lens is used in conjunction with an infrared detector with a planar rigid substrate, the infrared detector will exhibit a phenomenon where the image is clear at the focal point and becomes increasingly blurry the further away from the focal point, due to the spherical aberration of the single lens. To address this, in existing infrared detection systems, high-resolution imaging of the infrared detector is achieved through multiple lenses to correct optical aberrations and flatten the projected image on the plane, but this significantly increases the complexity, size, and cost of the system.

[0080] In this regard, when external infrared light illuminates the infrared detection system provided in this embodiment, a single lens can converge external infrared light from various incident directions to multiple back focal points located at the infrared detector, thereby forming a clear image at the multiple back focal points. This imaging method provided in this embodiment reduces the number of lenses, thereby reducing the size and weight of the infrared detection system, saving manufacturing costs, and facilitating assembly and portability.

[0081] 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.

[0082] 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 detector, wherein, include: Base; and A quantum dot detection structure, wherein the quantum dot detection structure is located on one side of the substrate; The quantum dot detection structure includes at least two infrared photosensitive layers stacked sequentially on one side of the substrate, each of which responds to a different infrared band. The quantum dot detection structure is used to output corresponding electrical signals to the substrate in response to infrared light signals of different wavelengths.

2. The infrared detector according to claim 1, wherein, Each of the infrared photosensitive layers forms a PN junction, and two adjacent infrared photosensitive layers form two reverse PN junctions.

3. The infrared detector according to claim 1, wherein, The quantum dot detector structure includes: A plurality of first electrodes are spaced apart on one side of the substrate; The first infrared photosensitive layer is located on the side of the first electrode opposite to the substrate; The second infrared photosensitive layer is located on the side of the first infrared photosensitive layer opposite to the first electrode; and The second electrode is located on the side of the second infrared photosensitive layer that is opposite to the first infrared photosensitive layer.

4. The infrared detector according to claim 3, wherein, The first infrared photosensitive layer includes a first N-type quantum dot layer, a first intrinsic quantum dot layer, and a first P-type quantum dot layer stacked sequentially along the direction from the first electrode to the second electrode; The second infrared photosensitive layer includes a second P-type quantum dot layer, a second intrinsic quantum dot layer, and a second N-type quantum dot layer stacked sequentially along the direction from the first electrode to the second electrode.

5. The infrared detector according to claim 4, wherein, The first P-type quantum dot layer is reused to form the second P-type quantum dot layer.

6. The infrared detector according to claim 4, wherein, The response bands of the first intrinsic quantum dot layer and the second intrinsic quantum dot layer are any two of short-wave infrared, mid-wave infrared and long-wave infrared.

7. An infrared detection system, wherein, Includes a power supply and an infrared detector as described in any one of claims 1-6; The power supply is connected to the infrared detector and is used to provide an activation voltage to the infrared detector.

8. The infrared detection system according to claim 7, wherein, One end of the power supply is connected to the base of the infrared detector, and the other end is connected to the second electrode of the infrared detector.

9. The infrared detection system according to claim 7, wherein, The power supply includes a first power supply and a second power supply; The first power source is used to provide a positive voltage, and the second power source is used to provide a negative voltage.

10. The infrared detection system according to claim 7, wherein, It also includes lenses; The lens is located on the light-incident surface of the infrared detector.

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