CN118571967A - Infrared focal plane detector, infrared focal plane detector system and preparation method - Google Patents

Abstract

The present disclosure relates to an infrared focal plane detector, system and preparation method, wherein the infrared focal plane detector comprises: a flexible curved surface substrate and a quantum dot detection structure; the quantum dot detection structure is located on the light incident side of the flexible curved surface substrate; the quantum dot detection structure is used to respond to external infrared ambient light signals to output electrical signals to the flexible curved surface substrate to a readout circuit of the flexible curved surface substrate. Thus, by arranging the quantum dot detection structure on the light incident side of the flexible curved surface substrate, it is ensured that the quantum dot detection structure is effectively coupled with the flexible curved surface substrate, thereby facilitating the large-scale preparation and application of the infrared focal plane detector.

Description

Infrared focal plane detector, system and preparation method

Technical Field

The present disclosure relates to the field of infrared detection technology, and in particular to an infrared focal plane detector, a system and a preparation method thereof.

Background Art

In the field of infrared imaging, infrared detectors have developed from single-unit to multi-unit, and then from multi-unit to focal plane, forming a variety of types of infrared detectors, such as: infrared detectors integrating flexible curved substrates with traditional flexible sensing functional units, which provide great potential and development space for solving the array setting of sensors on flexible curved substrates, and have become a focus of attention in the field of infrared imaging.

However, the crystal epitaxial materials used in current infrared detectors are generally rigid materials that are not easy to bend or compress, and the crystal lattice does not match the flexible curved substrate, so it is difficult to grow on a flexible curved substrate, which limits the large-scale preparation and application of flexible infrared focal plane detectors.

Summary of the invention

In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides an infrared focal plane detector, a system and a preparation method.

The present disclosure provides an infrared focal plane detector, comprising: a flexible curved substrate and a quantum dot detection structure;

The quantum dot detection structure is located on the light incident surface side of the flexible curved substrate;

The quantum dot detection structure is used to respond to external infrared ambient light signals and output electrical signals to the flexible curved substrate to a readout circuit of the flexible curved substrate.

Optionally, the quantum dot detection structure comprises:

A plurality of first electrodes, wherein the plurality of first electrodes are arranged at intervals in the plane of the flexible curved substrate, and the first electrodes are electrically connected to the readout circuit;

A quantum dot infrared absorption layer, located on a side of the first electrode away from the flexible curved substrate, and filling a gap between the first electrodes;

The second electrode is arranged on a side of the quantum dot infrared absorption layer away from the flexible curved substrate.

Optionally, the quantum dot detection structure comprises:

A plurality of first electrodes, wherein the plurality of first electrodes are arranged at intervals in the plane of the flexible curved substrate, and the first electrodes are electrically connected to the readout circuit;

An N-type quantum dot layer, located on a side of the first electrode away from the flexible curved substrate, and filling a gap between the first electrodes;

A quantum dot infrared absorption layer, located on a side of the N-type quantum dot layer away from the first electrode;

A P-type quantum dot layer, located on a side of the quantum dot infrared absorption layer away from the N-type quantum dot layer;

The second electrode is located on a side of the P-type quantum dot layer away from the quantum dot infrared absorption layer.

Optionally, the thickness of the N-type quantum dot layer is: 5nm~10nm;

The thickness of the quantum dot infrared absorption layer is 200-1000 nm;

The thickness of the P-type quantum dot layer is 5nm-10nm.

Optionally, the N-type quantum dot layer includes at least one of bismuth selenide, bismuth sulfide, bismuth telluride, zinc oxide and cadmium selenide;

The P-type quantum dot layer includes at least one of poly 3-hexylthiophene, poly (3,4-ethylenedioxythiophene) polystyrene sulfonate, 2,2',7,7'-tetrakis [N,N-di (4-methoxyphenyl) amino] -9,9'-spirobifluorene and poly triarylamine.

Optionally, the quantum dot infrared absorption layer includes colloidal quantum dots, and the colloidal quantum dots include at least one of lead sulfide, lead selenide, mercury telluride, mercury selenide, cadmium sulfide, cadmium telluride, cadmium selenide, silver sulfide, silver telluride, silver selenide and mercury cadmium telluride.

Optionally, the radius of curvature of the flexible curved substrate is greater than or equal to 3 mm.

The present disclosure also provides an infrared focal plane detection system, comprising an imaging lens and any of the above infrared focal plane detectors;

Wherein, the imaging lens is located on a light incident surface side of the infrared focal plane detector.

The present disclosure also provides a method for preparing an infrared focal plane detector, the method comprising:

Providing a flexible curved substrate;

Forming a quantum dot detection structure on one side of the light incident surface of the flexible curved substrate;

The quantum dot detection structure is used to respond to external infrared ambient light signals and output electrical signals to the flexible curved substrate to a readout circuit of the flexible curved substrate.

Optionally, forming a quantum dot detection structure on one side of the light incident surface of the flexible curved substrate includes:

The quantum dot infrared absorption layer of the quantum dot detection structure is stacked on the light incident surface side of the flexible curved substrate by any one of spin coating, spray coating and drop coating.

Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

The infrared focal plane detector provided by the embodiment of the present disclosure includes: a flexible curved substrate and a quantum dot detection structure; the quantum dot detection structure is located on the light incident side of the curved substrate; the quantum dot detection structure is used to respond to the external infrared ambient light signal to the flexible curved substrate and output an electrical signal to the readout circuit of the flexible curved substrate. In this way, by arranging the quantum dot detection structure on the light incident side of the flexible curved substrate, it is ensured that the quantum dot detection structure is effectively coupled with the flexible curved substrate, thereby facilitating the large-scale preparation and application of the infrared focal plane detector.

BRIEF DESCRIPTION OF THE DRAWINGS

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

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

FIG1 is a schematic diagram of the structure of an infrared focal plane detector provided by an embodiment of the present disclosure;

FIG2 is a schematic diagram of the structure of another infrared focal plane detector provided by an embodiment of the present disclosure;

FIG3 is a schematic diagram of the structure of another infrared focal plane detector provided by an embodiment of the present disclosure;

FIG4 is a schematic diagram of spectral absorption of an infrared focal plane detector provided by an embodiment of the present disclosure;

FIG5 is a schematic diagram of the structure of an infrared focal plane detection system provided by an embodiment of the present disclosure;

FIG6 is a schematic flow chart of a method for preparing an infrared focal plane detector provided in an embodiment of the present disclosure.

Among them, 100, infrared focal plane detector; 110, flexible curved substrate; 120, quantum dot detection structure; 121, first electrode; 122, quantum dot infrared absorption layer; 123, second electrode; 124, N-type quantum dot layer; 125, P-type quantum dot layer; 130, imaging lens.

DETAILED DESCRIPTION

In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme 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.

In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

First, in combination with the relevant background, the defects of the prior art and the improvements of the present application are explained.

In the field of infrared detection technology, infrared detectors are devices used to convert external infrared ambient light signals (also called infrared radiation signals) into electrical signal outputs. They have developed from single units to multiple units, and then from multiple units to focal planes, achieving a leap from point source detection to target thermal imaging. This has led to the formation of a wide variety of infrared detectors, providing ample choices for the system application of infrared detectors.

Among them, high-resolution imaging of infrared detectors is achieved through a multi-lens system to correct optical aberrations and flatten the projected image on a plane, which significantly increases the complexity, size and cost of the system. In this regard, if a single lens is used to cover the real image, it will be affected by the spherical aberration of the lens, resulting in a significant spatial mismatch of the focus on the image. Although the human eye only includes a simple single-lens imaging system, it is able to provide high-resolution imaging with adjustable zoom capabilities. This excellent performance stems from the curved retina, which can correct spherical aberration by matching the curvature of the lens focal plane. Therefore, inspired by the unique advantages of biological eyes such as Petzval-matched curvature, wide field of view and simplified lens system, electronic eye systems have received increasing attention and research, but it is relatively complex and expensive to directly manufacture infrared detectors on bendable flexible surfaces, and the available instruments are limited.

With the development of semiconductor manufacturing technology, a group of miniature photodetectors separated by electrically interconnected metal traces can be prepared based on mature semiconductor manufacturing technology. They are initially manufactured on a flexible substrate with a planar structure, and then the planar array is bent or folded to shape a hemispherical structure. With the manufacturing advantages of the flexible array, the flexible substrate with a hemispherical structure is integrated with the traditional flexible sensing functional unit to improve the sensitivity and dimension of the infrared detector. This sensing technology based on a flexible substrate provides great development potential and room for improvement for realizing the arraying of sensing functional units on a flexible substrate.

However, infrared detectors are mainly obtained by growing crystal epitaxial materials on planar substrates, where the materials of the planar substrates are rigid and brittle crystal materials, such as cadmium zinc telluride (CdZeTe), gallium arsenide (GaAs), indium arsenide (InAs) and indium phosphide (InP), which do not have the ability to bend. Commonly used crystal epitaxial materials are rigid gallium arsenide (InGaAs), indium antimony (InSb) and mercury cadmium telluride (MCT), etc. Under normal circumstances, crystal epitaxial materials require a substrate with a lattice matching them to grow. However, since crystal epitaxial materials are not easy to bend or compress, and the lattice does not match the flexible curved substrate, they are difficult to grow on a flexible curved substrate.

At present, the existing flexible infrared focal plane detectors use flip-chip bonding to achieve the bonding of crystal epitaxial materials and flexible curved substrates. This method has a long preparation cycle, slow productivity, high material processing costs, and low bonding success rate. It may even cause cold solder joints during welding, thereby reducing the detection efficiency of the infrared detector and limiting the large-scale preparation and application of flexible infrared focal plane detectors.

In response to at least one of the above problems, the embodiments of the present disclosure provide an infrared focal plane detector, system and preparation method. Specifically, for the infrared focal plane detector, since colloidal quantum dots (CQD) are an infrared material with synthetic scalability, mechanical flexibility, and wide-spectrum adjustability, by setting the quantum dot detection structure on the light-incident side of the flexible curved substrate, the quantum dot detection structure and the flexible curved substrate can be effectively coupled without welding, which is conducive to the large-scale preparation and application of infrared focal plane detectors, such as: it can be applied to chemical detection, wafer detection, object monitoring, national defense security and other fields.

The infrared focal plane detector, system and preparation method provided by the embodiments of the present disclosure are exemplarily described below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of the structure of an infrared focal plane detector provided by an embodiment of the present disclosure. Referring to Fig. 1, the infrared focal plane detector includes: a flexible curved substrate 110 and a quantum dot detection structure 120; the quantum dot detection structure 120 is located on the light incident side of the flexible curved substrate 110; the quantum dot detection structure 120 is used to respond to external infrared ambient light signals to output electrical signals to the flexible curved substrate 110 to the readout circuit of the flexible curved substrate 110.

The flexible curved substrate 110 is a silicon-based readout circuit substrate for carrying the quantum dot detection structure 120. For example, the flexible curved substrate 110 may be made of polydimethylsiloxane, polyimide or other materials, which are not limited herein.

The quantum dot detection structure 120 is composed of quantum dot materials. Specifically, due to the advantages of quantum dot materials such as synthetic scalability, mechanical flexibility, and wide-spectrum adjustability, the quantum dot detection structure 120 can be directly coupled with the flexible curved substrate 110, overcoming the problem that crystal epitaxial materials are difficult to grow on the flexible curved substrate 110, and there is no need to use the flip-chip bonding method required for the preparation of existing infrared detectors, thereby reducing the preparation cost of the flexible infrared focal plane detector and improving the yield rate, which is conducive to the large-scale preparation and application of flexible infrared focal plane detectors.

Specifically, when external infrared ambient light is incident on the infrared focal plane detector, the quantum dot detection structure 120 will perform a photoelectric response based on the external infrared ambient light signal, that is, convert the external infrared ambient light signal into an electrical signal, which is then transmitted to the flexible curved substrate 110. The electrical signal is converted into a digital signal and read out through the (signal) readout circuit in the flexible curved substrate 110, which facilitates subsequent processing of the digital signal by other related circuits for infrared imaging.

The infrared focal plane detector provided by the embodiment of the present disclosure includes: a flexible curved substrate 110 and a quantum dot detection structure 120; the quantum dot detection structure 120 is located on the light incident side of the flexible curved substrate 110; the quantum dot detection structure 120 is used to respond to the external infrared ambient light signal to output an electrical signal to the flexible curved substrate 110 to the readout circuit of the flexible curved substrate 110. In this way, by arranging the quantum dot detection structure 120 on the light incident side of the flexible curved substrate 110, it is ensured that the quantum dot detection structure 120 is effectively coupled with the flexible curved substrate 110, thereby facilitating the large-scale preparation and application of the infrared focal plane detector.

In some embodiments, FIG2 is a schematic diagram of the structure of another infrared focal plane detector provided by an embodiment of the present disclosure. Based on FIG1, referring to FIG2, the quantum dot detection structure 120 includes: a plurality of first electrodes 121, the plurality of first electrodes 121 are arranged at intervals in the plane of the flexible curved substrate 110, and the first electrodes 121 are electrically connected to the readout circuit; a quantum dot infrared absorption layer 122, located on the side of the first electrode 121 away from the flexible curved substrate 110, and filling the gap between the first electrodes 121; a second electrode 123, arranged on the side of the quantum dot infrared absorption layer 122 away from the flexible curved substrate 110.

For example, taking the orientation and structure shown in FIG2 as an example, on the side of the flexible curved substrate 110 that is bent upward, a plurality of first electrodes 121 are spaced apart in the upper plane of the flexible curved substrate 110, a quantum dot infrared absorption layer 122 fills the gaps between the first electrodes 121 and covers the plurality of first electrodes 121, and a second electrode 123 is located above the quantum dot infrared absorption layer 122. In this way, a photoconductive infrared focal plane detector is formed as a whole, which has a simple structure and reduces the complexity of preparing the infrared focal plane detector.

Among them, the first electrode 121 is the bottom electrode of the quantum dot detection structure 120, which is used to collect the electrical signal (commonly known as electron) generated by the photoelectric response. Exemplarily, the first electrode 121 can be one or more of indium tin oxide (ITO), fluorine-doped zinc oxide (FTO), gold, silver, copper, aluminum, and chromium, and is stacked into a preset thickness by physical vapor deposition (PVD) such as thermal evaporation and magnetron sputtering, or by chemical vapor deposition (CVD) to a preset thickness, and a patterned array-arranged first electrode 121 is prepared by a photolithography mask process, such as photolithography followed by etching, or photolithography followed by stripping. In other embodiments, other electrode materials known to those skilled in the art can also be used to prepare the first electrode 121, which is not limited here.

Among them, the second electrode 123 is the top electrode of the quantum dot detection structure 120, which is used to collect holes generated by the photoelectric response. Exemplarily, the second electrode 123 can be any one of gold, silver, copper and aluminum, and is prepared by physical vapor deposition (PVD) such as thermal evaporation, electron beam evaporation or magnetron sputtering, or by chemical vapor deposition (CVD). It is only necessary to ensure that the preparation material of the top electrode does not affect its light transmittance and facilitates the transmission of external infrared ambient light. The preparation material of the top electrode is not limited here.

For example, the thickness of the first electrode 121 may be 5 nm to 200 nm, and the thickness of the second electrode 123 may be 5 nm to 50 nm, which is not limited herein.

The quantum dot infrared absorption layer 122 is a quantum dot layer for photoelectric response, i.e., an intrinsic quantum dot layer. Specifically, after the external infrared ambient light passes through the second electrode 123, the quantum dot infrared absorption layer 122 can generate photogenerated electron-hole pairs, and then the electrons are transmitted to the first electrode 121, and the holes are transmitted to the second electrode 123. Since the first electrode 121 is electrically connected to the readout circuit of the flexible curved substrate 110, the electrons can be transmitted to the readout circuit via the first electrode 121, and the readout circuit performs relevant processing on the electrons (i.e., electrical signals).

In this way, by arranging multiple first electrodes 121 at intervals in the plane of the flexible curved substrate, the effective contact area between the quantum dot infrared absorption layer 122 and the flexible curved substrate 110 is increased, thereby ensuring a good coupling effect between the quantum dot infrared absorption layer 122 and the flexible curved substrate 110; at the same time, the first electrode 121 can also be connected one-to-one with the pixel electrode in the flexible curved substrate 110, so that the flexible curved substrate 110 can collect multiple independent electrical signals. The spacing distance between adjacent first electrodes 121 can be set according to the preparation requirements of the infrared focal plane detector, and there is no limitation on this.

In some embodiments, FIG3 is a schematic diagram of the structure of another infrared focal plane detector provided by an embodiment of the present disclosure. Based on FIG1, referring to FIG3, the quantum dot detection structure 120 includes: a plurality of first electrodes 121, the plurality of first electrodes 121 are arranged at intervals in the plane of the flexible curved substrate 110, and the first electrodes 121 are electrically connected to the readout circuit; an N-type quantum dot layer 124, located on the side of the first electrode 121 away from the flexible curved substrate 110, and filling the gap between the first electrodes 121; a quantum dot infrared absorption layer 122, located on the side of the N-type quantum dot layer 124 away from the first electrode 121; a P-type quantum dot layer 125, located on the side of the quantum dot infrared absorption layer 122 away from the N-type quantum dot layer 124; and a second electrode 123, located on the side of the P-type quantum dot layer 125 away from the quantum dot infrared absorption layer 122.

For example, taking the orientation and structure shown in FIG3 as an example, on the side of the flexible curved substrate 110 that is bent upward, a plurality of first electrodes 121 are arranged at intervals in the upper plane of the flexible curved substrate 110, an N-type quantum dot layer 124 fills the gaps between the first electrodes 121 and covers the plurality of first electrodes 121, and a quantum dot infrared absorption layer 122, a P-type quantum dot layer 125, and a second electrode 123 are sequentially stacked above the N-type quantum dot layer 124. In this way, a photovoltaic infrared focal plane detector is formed as a whole.

Specifically, since the N-type quantum dot layer 124 and the P-type quantum dot layer 125 are located on opposite sides of the quantum dot infrared absorption layer 122, a PN junction can be formed between the three. On this basis, when the external infrared ambient light passes through the second electrode 123, the electrons and holes generated in the quantum dot infrared absorption layer 122 diffuse unevenly, thereby forming a built-in potential inside the photovoltaic infrared focal plane detector. The electron-hole pairs can be dissociated into free electrons and holes under the action of the built-in potential. The holes are transmitted to the second electrode 123 via the P-type quantum dot layer 125, and the electrons are transmitted to the first electrode 121 via the N-type quantum dot layer 124.

In some embodiments, based on FIG. 2 and FIG. 3 , the infrared focal plane detector further includes an external power supply (not shown in the figures).

The external power source is connected to the second electrode 123 and the first electrode 121, respectively, for applying a working voltage to the infrared focal plane detector. It should be noted that by applying a working voltage to the photoconductive infrared focal plane detector and the photovoltaic infrared focal plane detector, respectively, the electrical signal (i.e., electron) generated by the photoelectric response can be driven to move to the flexible curved substrate 110 more quickly, forming a directional moving current, so that the electrical signal in the current can be collected and processed in time.

In addition, after an external power supply applies an operating voltage to the photovoltaic infrared focal plane detector, its built-in potential can be further enhanced, which increases the speed at which electron-hole pairs dissociate into free electrons and holes, as well as the transmission efficiency of electrons and holes, thereby increasing the current saturation. Compared with the photoconductive infrared focal plane detector, the photovoltaic infrared focal plane detector has a better signal-to-noise ratio, ensuring good detection performance.

In some embodiments, based on FIG. 2 and FIG. 3 , the thickness of the N-type quantum dot layer 124 is 5 nm to 10 nm; the thickness of the quantum dot infrared absorption layer 122 is 200 to 1000 nm; and the thickness of the P-type quantum dot layer 125 is 5 nm to 10 nm.

In this way, by setting the thickness of the N-type quantum dot layer 124, the quantum dot infrared absorption layer 122 and the P-type quantum dot layer 125 to the above range, it helps electrons and holes to move in corresponding directions, ensuring the transmission efficiency of electrons and holes, so that the infrared focal plane detector can form a good detection effect. The specific values of the thickness of the N-type quantum dot layer 124, the quantum dot infrared absorption layer 122 and the P-type quantum dot layer 125 can be set according to the transmission requirements of electrons and holes, and are not limited here.

In some embodiments, based on Figure 3, the N-type quantum dot layer 124 includes at least one of bismuth selenide, bismuth sulfide, bismuth telluride, zinc oxide and cadmium selenide; the P-type quantum dot layer 125 includes at least one of poly 3-hexylthiophene, poly (3,4-ethylenedioxythiophene) polystyrene sulfonate, 2,2',7,7'-tetrakis [N,N-di (4-methoxyphenyl) amino] -9,9'-spirobifluorene and polytriarylamine.

In addition, the N-type quantum dot layer 124 may also be one or more of the N-type quantum dot films of the intrinsic quantum dot layer, and the P-type quantum dot layer 125 may also be one or more of the P-type quantum dot films of the intrinsic quantum dot layer.

In this way, the N-type quantum dot layer 124 and the P-type quantum dot layer 125 in the embodiment of the present disclosure are composed of the above corresponding materials, which facilitates direct coupling with the flexible curved substrate 110, thereby reducing the difficulty of preparing the infrared focal plane detector during preparation and improving the preparation efficiency and yield of the infrared focal plane detector.

In some embodiments, based on Figures 2 and 3, the quantum dot infrared absorption layer 122 includes colloidal quantum dots, and the colloidal quantum dots include at least one of lead sulfide, lead selenide, mercury telluride, mercury selenide, cadmium sulfide, cadmium telluride, cadmium selenide, silver sulfide, silver telluride, silver selenide and mercury cadmium telluride.

Among them, the colloidal quantum dots included in the quantum dot infrared absorption layer 122 are intrinsic (colloidal) quantum dots, and their absorption wavelength is related to the reaction time and reaction temperature in the synthesis process of the intrinsic quantum dots. Specifically, in the synthesis process of intrinsic colloidal quantum dots, by accurately controlling the reaction time and reaction temperature, the absorption wavelength and particle size of the intrinsic colloidal quantum dots can be accurately controlled. For example: the longer the reaction time and the higher the reaction temperature, the longer the absorption wavelength and the larger the particle size of the intrinsic colloidal quantum dots. In this way, the quantum dot infrared absorption layer 122 in the embodiment of the present disclosure can cover any one of short-wave infrared, medium-wave infrared and long-wave infrared, thereby forming a monochromatic infrared focal plane detector. Here, the absorption wavelength and particle size of the intrinsic colloidal quantum dots are not limited.

For example, Fig. 4 is a schematic diagram of the spectral absorption of an infrared focal plane detector provided by an embodiment of the present disclosure. Referring to Fig. 4, the horizontal axis X1 represents the wave number (i.e., the inverse of the wavelength), the unit is cm ^-1 , the vertical axis Y1 represents the absorbance, which is a dimensionless unit and can be expressed by au (abbreviation of arbitrary units); L31, L32, L33, L34, and L35 represent the spectral absorption curves of quantum dots with wavelengths of 1.7um, 2um, 2.5um, 3um, and 3.7um, respectively, indicating that quantum dots of different bands can be synthesized when preparing an infrared focal plane detector, and an infrared focal plane detector with a spectral detection range of 1.7um-3.7um can be realized.

In some embodiments, based on FIG. 2 and FIG. 3 , the infrared focal plane detector further includes: a data analysis and imaging circuit (not shown in the figures), and the flexible curved substrate 110 is electrically connected to the data analysis and imaging circuit.

The data analysis and imaging circuit includes a signal processor. Specifically, when an object or a human body enters the detection range of the infrared focal plane detector, the infrared light (i.e., external infrared ambient light) emitted by it is received by the quantum dot infrared absorption layer of the infrared focal plane detector and converted into an electrical signal, and then the electrical signal is transmitted to the data analysis and imaging circuit via the flexible curved substrate 110, and the signal processor of the data analysis and imaging circuit performs signal amplification, filtering and other processing on it, and performs infrared imaging based on the processed signal to determine the existence, movement, temperature change, etc. of the object or human body.

In some embodiments, based on FIG. 2 and FIG. 3 , the radius of curvature of the flexible curved substrate 110 is greater than or equal to 3 mm.

Specifically, by setting the curvature radius of the flexible curved substrate 110 to be greater than or equal to 3 mm, the focal point of the incident external infrared ambient light will be on the curved focal plane of the infrared focal plane detector, avoiding image distortion and ensuring good imaging effects, that is, achieving clear imaging with a large field of view and high resolution.

The thickness of the flexible curved substrate 110 is less than or equal to 50 μm. Thus, on the basis that the radius of curvature of the flexible curved substrate 110 is greater than or equal to 3 mm, by setting its thickness to be less than or equal to 50 μm, it is beneficial to further improve the imaging effect of the infrared focal plane detector, and the setting can be made according to the imaging requirements of the infrared focal plane detector, which is not limited here.

On the basis of the above-mentioned embodiments, an embodiment of the present disclosure further provides an infrared focal plane detection system. FIG5 is a schematic structural diagram of an infrared focal plane detection system provided by an embodiment of the present disclosure. Referring to FIG5 , the infrared focal plane detection system includes an imaging lens 130 and any one of the infrared focal plane detectors 100 provided by the above-mentioned embodiments.

The imaging lens 130 is located on the light incident side of the infrared focal plane detector 100. Specifically, when external infrared ambient light irradiates the infrared focal plane detection system, the imaging lens 130 can converge the external infrared ambient light of various incident directions to multiple rear focal points located at the infrared focal plane detector 100, thereby forming a clear image at the multiple rear focal points.

In this way, compared with the existing infrared detectors that use multiple groups of imaging lenses for imaging, the embodiment of the present disclosure can focus the external infrared ambient light on the infrared focal plane detector 100 through a group of imaging lenses 130, reducing the optical components required for imaging by the infrared focal plane detection system, thereby reducing the size and weight of the infrared focal plane detection system, thereby saving the preparation cost of the infrared focal plane detection system and facilitating assembly and carrying.

The embodiments of the present disclosure also provide a method for preparing an infrared focal plane detector, which is used to prepare any one of the infrared focal plane detectors provided in the above embodiments.

In some embodiments, FIG6 is a schematic flow chart of a method for preparing an infrared focal plane detector provided by an embodiment of the present disclosure. Referring to FIG6 , the method includes:

S210, providing a flexible curved substrate.

For example, acetone, isopropyl alcohol and deionized water may be used to clean the flexible curved surface substrate in sequence to prepare for subsequent use.

S220, forming a quantum dot detection structure on the light incident surface side of the flexible curved substrate.

Among them, the quantum dot detection structure is used to respond to external infrared ambient light signals to output electrical signals to the flexible curved substrate to the readout circuit of the flexible curved substrate. The specific preparation steps of the quantum dot detection structure will be described in detail later and will not be repeated here.

In some embodiments, based on FIG. 6 , S220 specifically includes the following steps:

By using any one of spin coating, spray coating and drop coating, a quantum dot infrared absorption layer of a quantum dot detection structure is stacked on the light incident surface side of the flexible curved substrate.

Specifically, compared with the prior art that realizes bonding of crystal epitaxial materials to flexible curved substrates by flip-chip bonding, which causes various adverse problems, the embodiments of the present disclosure prepare the quantum dot infrared absorption layer on the flexible curved substrate by spin coating, spraying or drip coating, thereby making the preparation process of the flexible infrared focal plane detector simpler, thereby effectively reducing the preparation cost of the flexible infrared focal plane detector and reducing the design complexity of the flexible infrared focal plane detector.

Exemplarily, the thickness of the quantum dot infrared absorption layer can be 200nm~1000nm, such as 200nm, 400nm, 600nm or other thickness values. In other embodiments, the thickness of the quantum dot infrared absorption layer can also be other numerical ranges or numerical sizes, which can be set according to the imaging requirements of the infrared focal plane detector and is not limited here.

It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

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

Claims (10)

1. An infrared focal plane detector, comprising: a flexible curved substrate and a quantum dot detection structure;

the quantum dot detection structure is positioned on one side of the light incident surface of the flexible curved substrate;

The quantum dot detection structure is used for responding to an external infrared environment light signal and outputting an electric signal to the flexible curved surface substrate to a reading circuit of the flexible curved surface substrate.

2. The infrared focal plane detector of claim 1, wherein the quantum dot detection structure comprises:

The first electrodes are arranged at intervals in the plane of the flexible curved surface substrate and are electrically connected with the readout circuit;

the quantum dot infrared absorption layer is positioned on one side of the first electrode, which is away from the flexible curved surface substrate, and fills a gap between the first electrodes;

the second electrode is arranged on one side of the quantum dot infrared absorption layer, which is away from the flexible curved surface substrate.

3. The infrared focal plane detector of claim 1, wherein the quantum dot detection structure comprises:

The first electrodes are arranged at intervals in the plane of the flexible curved surface substrate and are electrically connected with the readout circuit;

the N-type quantum dot layer is positioned on one side of the first electrode, which is away from the flexible curved surface substrate, and fills a gap between the first electrodes;

the quantum dot infrared absorption layer is positioned at one side of the N-type quantum dot layer, which is away from the first electrode;

the P-type quantum dot layer is positioned on one side of the quantum dot infrared absorption layer, which is away from the N-type quantum dot layer;

and the second electrode is positioned at one side of the P-type quantum dot layer, which is away from the quantum dot infrared absorption layer.

4. An infrared focal plane detector as recited in claim 3, wherein,

The thickness of the N-type quantum dot layer is as follows: 5 nm-10 nm;

the thickness of the quantum dot infrared absorption layer is as follows: 200-1000 nm;

The thickness of the P-type quantum dot layer is as follows: 5nm to 10nm.

5. The infrared focal plane detector of claim 3, wherein the N-type quantum dot layer comprises at least one of bismuth selenide, bismuth sulfide, bismuth telluride, zinc oxide, and cadmium selenide;

The P-type quantum dot layer comprises at least one of poly (3-hexylthiophene), poly (3, 4-ethylenedioxythiophene) polystyrene sulfonate, 2', 7' -tetrakis [ N, N-bis (4-methoxyphenyl) amino ] -9,9' -spirobifluorene and poly (triarylamine).

6. An infrared focal plane detector according to claim 2 or 3, characterized in that,

The quantum dot infrared absorption layer comprises colloidal quantum dots, wherein the colloidal quantum dots comprise at least one of lead sulfide, lead selenide, mercury telluride, mercury selenide, cadmium sulfide, cadmium telluride, cadmium selenide, silver sulfide, silver telluride, silver selenide and mercury cadmium telluride.

7. The infrared focal plane detector of claim 1, wherein the radius of curvature of the flexible curved substrate is greater than or equal to 3 millimeters.

8. An infrared focal plane detection system comprising an imaging lens and an infrared focal plane detector as claimed in any one of claims 1 to 7;

The imaging lens is positioned on one side of the light incident surface of the infrared focal plane detector.

9. A method of making an infrared focal plane detector, the method comprising:

Providing a flexible curved substrate;

Forming a quantum dot detection structure on one side of the light incident surface of the flexible curved surface substrate;

The quantum dot detection structure is used for responding to an external infrared environment light signal and outputting an electric signal to the flexible curved surface substrate to a reading circuit of the flexible curved surface substrate.

10. The method for manufacturing an infrared focal plane detector according to claim 9, wherein forming a quantum dot detection structure on the light incident surface side of the flexible curved substrate comprises:

And stacking and forming a quantum dot infrared absorption layer of the quantum dot detection structure on one side of the light incident surface of the flexible curved surface substrate by adopting any one of spin coating, spray coating and drop coating.