Quantum dot flexible probe and preparation method thereof

Abstract

The application provides a quantum dot flexible detector and a preparation method thereof, to solve the problem that the quantum dot flexible detector is difficult to adapt to a curved surface application scene. The quantum dot flexible detector comprises a bending area, and the bending area comprises a stress neutral area, which comprises a substrate; a device functional layer arranged on one side of the substrate, the device functional layer comprising a quantum dot absorption layer; and a stress adjusting layer arranged on the side of the device functional layer away from the substrate, the stress adjusting layer regulating the device functional layer to be located in the stress neutral area.

Description

Technical Field

[0001] This application relates to the field of flexible infrared photodetector technology, and in particular to a quantum dot flexible detector and its fabrication method. Background Technology

[0002] The market demand for short-wave infrared detectors has been steadily increasing year by year. However, the mainstream short-wave infrared detectors currently on the market are all fabricated using rigid substrates as carriers, which cannot meet the needs of devices that are bent or attached to curved surfaces in emerging application scenarios. There is an urgent need to develop a flexible short-wave infrared detector. Summary of the Invention

[0003] In view of this, this application proposes a quantum dot flexible detector and its fabrication method to solve the problem that quantum dot flexible detectors are difficult to adapt to curved surface application scenarios.

[0004] To solve the above-mentioned technical problems, the following technical solutions are adopted in the embodiments of this application:

[0005] In a first aspect, this application provides a quantum dot flexible detector, which includes a bending region and a stress-neutral region, and includes a substrate; a device functional layer disposed on one side of the substrate, the device functional layer including a quantum dot absorption layer; and a stress adjustment layer disposed on the side of the device functional layer away from the substrate, the stress adjustment layer regulating the device functional layer to be located in the stress-neutral region.

[0006] According to one embodiment of this application, the stress-adjusting layer has the same thickness as the substrate; the thickness of the stress-adjusting layer ranges from 10 to 200 μm.

[0007] According to one embodiment of this application, the edges of the substrate and the stress-adjusting layer are in close contact to form an inner packaging containment space, and the device functional layer is located within the inner packaging containment space.

[0008] According to one embodiment of this application, the stress-adjusting layer includes at least a first layer and a second layer; the materials of the first layer and the second layer are different; the second layer is located between adjacent first layers, and the first layer has one more layer than the second layer; the first layer and the second layer are alternately stacked, and the number of layers of the second layer is equal to that of the first layer; the surface of the stress-adjusting layer on the side away from the substrate includes at least one groove; the junction of the first layer and the second layer is complementary and interlocked.

[0009] According to one embodiment of this application, the stress-regulating layer is made of at least one of polyolefin elastomer and polyethylene terephthalate.

[0010] According to one embodiment of this application, the device functional layer further includes a bottom electrode, a hole transport layer, an electron transport layer, and a top electrode. The bottom electrode is attached to one side of the substrate, and the quantum dot absorption layer is disposed between the hole transport layer and the electron transport layer. The hole transport layer is disposed on the side of the bottom electrode away from the substrate, the electron transport layer is disposed on the side of the hole transport layer away from the bottom electrode, and the top electrode is disposed on the side of the electron transport layer away from the hole transport layer. The electron transport layer is disposed on the side of the bottom electrode away from the substrate, the hole transport layer is disposed on the side of the electron transport layer away from the bottom electrode, and the top electrode is disposed on the side of the hole transport layer away from the electron transport layer.

[0011] According to one embodiment of this application, at least one of the bottom electrode, hole transport layer, quantum dot absorption layer, electron transport layer, and top electrode is a stress-neutral region; the quantum dot absorption layer is a stress-neutral region.

[0012] According to one embodiment of this application, the material of the quantum dot absorption layer includes lead sulfide quantum dots-ethylenedithiol.

[0013] According to one embodiment of this application, the thickness of the quantum dot absorption layer ranges from 10 to 100 nm.

[0014] Secondly, this application provides a method for fabricating a quantum dot flexible detector, the quantum dot flexible detector including a bending region, the bending region including a stress neutral region, including: providing a substrate; providing a device functional layer, the device functional layer being disposed on one side of the substrate, the device functional layer including a quantum dot absorption layer; providing a stress adjustment layer, the stress adjustment layer being disposed on the side of the device functional layer away from the substrate, the stress adjustment layer regulating the device functional layer to be located in the stress neutral region.

[0015] The beneficial effects of this application are as follows: This application provides a quantum dot flexible detector, which includes a bending region and a stress-neutral region, and includes a substrate; a device functional layer disposed on one side of the substrate, the device functional layer including a quantum dot absorption layer; and a stress adjustment layer disposed on the side of the device functional layer away from the substrate. The stress adjustment layer regulates the device functional layer to be located in the stress-neutral region. Under bending conditions, the device functional layer is subjected to less stress, which improves the overall bending resistance of the device and solves the problem that quantum dot flexible detectors are difficult to adapt to curved surface application scenarios. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1This is a schematic diagram of the structure of a flexible quantum dot detector provided in an embodiment of this application; Figure 2 A schematic diagram of the structure of another quantum dot flexible detector provided in the embodiments of this application; Figure 3 A schematic diagram of another quantum dot flexible detector provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of a flexible quantum dot detector provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a stress-adjusting layer provided in an embodiment of this application; Figure 6 This is a schematic diagram of another stress-adjusting layer provided in an embodiment of this application; Figure 7 This is a schematic diagram of another stress-adjusting layer provided in an embodiment of this application; Figure 8 A schematic diagram of the structure of a quantum dot flexible detector is also provided for embodiments of this application; Figure 9 This is a schematic flowchart illustrating a method for fabricating a flexible quantum dot detector, as provided in an embodiment of this application.

[0017] Explanation of reference numerals in the attached figures 10-Quantum dot flexible detector; 101 - First non-bending area; 102 - Bending area; 103 - Second non-bending area; 104 - Inner packaging space; 1021 - Stress Neutral Region; 11-Substrate; 12-Device functional layer; 13-Stress conditioning layer; 121-Bottom electrode; 122-Hole transport layer; 123-Quantum dot absorption layer; 124-Electron transport layer; 125-Top electrode; 130 - Groove; 131 - First layer; 132 - Second layer. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0019] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in the embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0020] It should be understood that in the description of the embodiments of this application, the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the scheme of the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0021] Furthermore, when an element or layer is referred to as being "on" another element or layer, "connected to," or "bonded to" another element or layer, the element or layer may be directly on the other element or layer, directly connected to, or directly bonded to the other element or layer, or there may be intermediate elements or layers. However, when an element or layer is referred to as being "directly on" another element or layer, "directly connected to," or "directly bonded to" another element or layer, there are no intermediate elements or layers.

[0022] The terms First, Second, etc., are used to describe various elements, components, regions, layers, and / or parts, but these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, and / or part from another element, component, region, layer, and / or part.

[0023] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] Short-wave infrared detectors have extremely high application value, and the overall market demand for them has been steadily increasing year by year. Currently, mainstream short-wave infrared detectors in the industry are mainly fabricated using traditional epitaxial semiconductor materials such as indium gallium arsenide (IGaAs) and mercury cadmium telluride (HMCC), but the production cost of these devices is high. Lead sulfide (PbS) quantum dots are currently a popular research material in the field of short-wave infrared detection, providing a new technical path for the development of low-cost, high-performance short-wave infrared detector devices. The inventors have discovered that existing short-wave infrared detectors are all fabricated using rigid substrates, resulting in fixed device shapes and a lack of bending deformation capabilities, making them difficult to adapt to the requirements of curved surface bonding and flexible integration. After analyzing and researching the above problems, the inventors have proposed a solution that can solve the problem of the quantum dot flexible detector 10 being difficult to adapt to curved surface application scenarios.

[0025] The specific implementation of the embodiments of this application will be further described below with reference to the accompanying drawings.

[0026] Firstly, according to one embodiment of this application, please refer to... Figure 1 This application provides a quantum dot flexible detector 10, which includes a bending region 102 to meet the requirements of flexible devices. Furthermore, the quantum dot flexible detector 10 also includes a first non-bending region 101 and a second non-bending region 103. The bending region 102 connects the first non-bending region 101 and the second non-bending region 103, which can meet the needs of more product application scenarios.

[0027] The bending region 102 includes a stress-neutral region 1021. It should be noted that during the bending process of the device, there exists an ideal layer inside the device that is neither stretched nor compressed; the mechanical stress in this layer is zero. This layer is called the stress-neutral region 1021. In reality, this layer still has residual thermal stress, meaning the mechanical stress of the film layer located in the stress-neutral region 1021 is minimal. Using the stress-neutral region 1021 as a boundary, the further away from the stress-neutral region 1021, the greater the tensile or compressive strain it experiences. Specifically, the material located on the outer side of the bend (far from the center of curvature) is stretched, while the material located on the inner side of the bend (closer to the center of curvature) is compressed.

[0028] According to one embodiment of this application, a quantum dot flexible detector 10 includes a substrate 11, a device functional layer 12, and a stress adjustment layer 13. The device functional layer 12 is disposed on one side of the substrate 11 and includes a quantum dot absorption layer 123. The stress adjustment layer 13 is disposed on the side of the device functional layer 12 away from the substrate 11. The stress adjustment layer 13 regulates the device functional layer 12 to be located in a stress neutral region 1021. In the bending mode, the mechanical stress in the stress neutral region 1021 is minimal, and the stress on the device functional layer 12 is relatively small. After bending, the efficiency of the quantum dot flexible detector 10 decreases less, which is beneficial to improving the overall bending resistance of the device and extending the service life of the device.

[0029] According to one embodiment of this application, the stress adjustment layer 13 and the substrate 11 have the same thickness. By adjusting the thickness ratio of the stress adjustment layer 13 and the substrate, the functional layer 12 of the device is controlled at the stress neutral region 1021, which simplifies the process complexity.

[0030] According to one embodiment of this application, the thicknesses of the stress adjustment layer 13 and the substrate 11 may not be equal. That is, the thickness of the stress adjustment layer 13 is less than the thickness of the substrate 11, or the thickness of the stress adjustment layer 13 is greater than the thickness of the substrate 11. By adjusting the material, morphology and bonding process of the stress adjustment layer 13, the functional layer 12 of the device can be controlled at the position of the stress neutral region 1021, thereby achieving flexible control of the stress neutral region 1021. This is beneficial for the thinning of the device and increases its market competitiveness.

[0031] According to one embodiment of this application, the thickness of the stress adjustment layer 13 is in the range of 10 to 200 μm. The thickness of the stress adjustment layer 13 includes, but is not limited to, 10 μm, 80 μm, 100 μm, 130 μm, and 200 μm. The limitation of the thickness range of the stress adjustment layer 13 can ensure a sufficient thickness adjustment range, which is beneficial for adapting to different devices and ensuring that the device functional layer 12 is located in the stress center region.

[0032] According to one embodiment of this application, please refer to Figure 1 The edges of the substrate 11 and the stress-adjusting layer 13 are in close contact to form an inner packaging space 104. The device functional layer 12 is located within the inner packaging space 104. After lamination, the substrate 11 and the stress-adjusting layer 13 together constitute an inner packaging structure, which can isolate water and oxygen and improve the detector's resistance to water and oxygen.

[0033] According to one embodiment of this application, please refer to Figure 5 and Figure 6 The stress-adjusting layer 13 includes at least a first layer 131 and a second layer 132. This composite film can provide a greater range of thickness adjustment. Understandably, the stress-adjusting layer 13 can also be formed by laminating two or more film layers.

[0034] According to one embodiment of this application, the material of the first layer 131 is different from that of the second layer 132. The alternating material lamination forms the stress adjustment layer 13, which can adapt to more device requirements. It is understood that the stress adjustment layer 13 may also include two or more materials, and different material combinations can adapt to the requirements of different devices.

[0035] According to one embodiment of this application, please refer to Figure 6The second layer 132 is located between the adjacent first layer 131. The first layer 131 has one more layer than the second layer 132. After the stress adjustment layer 13 is laminated to form the stress adjustment layer 13, the surface of the stress adjustment layer 13 near the device functional layer 12 and the surface of the stress adjustment layer 13 away from the device functional layer 12 are made of the same material, which can effectively prevent the risk of device warping and cracking.

[0036] According to one embodiment of this application, please refer to Figure 5 The first layer 131 and the second layer 132 are stacked alternately, and the second layer 132 has the same number of layers as the first layer 131. This also allows the functional layer 12 of the control device to be located in the stress center region.

[0037] According to one embodiment of this application, please refer to Figure 4 The surface of the stress-adjusting layer 13 facing away from the substrate 11 includes at least one groove 130. The groove 130 can further avoid stress concentration and ensure the reliability of the device.

[0038] According to one embodiment of this application, the groove 130 can be provided only in the bending area 102. When the device is bent, it can effectively disperse the bending stress. While ensuring that the stress adjustment layer 13 regulates the functional layer 12 of the device in the stress center area, it can avoid the risk of cracking of the stress adjustment layer 13.

[0039] According to one embodiment of this application, the grooves 130 can be set at various positions of the stress adjustment layer 13 according to actual process requirements. It should be noted that the shape and arrangement of the grooves 130 are not limited, as long as they can meet the purpose of avoiding stress concentration. The thickness of the stress adjustment layer 13 with the grooves 130 is its average thickness.

[0040] According to one embodiment of this application, please refer to Figure 7 The first layer 131 and the second layer 132 are complementary and interlocked at the junction. This interlocking arrangement can avoid the warping of the stress adjustment layer 13 itself and improve the reliability of the device.

[0041] Specifically, the first layer 131 includes at least one groove 130, and the second layer 132 includes at least one groove 130. The grooves 130 of the first layer 131 and the grooves 130 of the second layer 132 are fitted together, so that the first layer 131 is fitted into the second layer 132. And so on, the adjacent film layers are fitted together by the fitting of the grooves 130. After lamination, a stress-adjusting layer 13 with stronger adhesion is obtained. The morphology, number and arrangement of the grooves 130 are not limited.

[0042] In another embodiment, at least two layers of the stress-adjusting layer 13 include grooves 130. These grooves 130 can ensure the interlocking between adjacent layers and also obtain a stress-adjusting layer 13 with strong adhesion. The morphology, number and arrangement of the grooves 130 are not limited.

[0043] According to one embodiment of this application, the first layer 131 includes at least one protrusion, and the second layer 132 includes at least one protrusion. The protrusions of the first layer 131 and the protrusions of the second layer 132 have sockets, so that the first layer 131 is fitted into the second layer 132. Similarly, adjacent film layers are fitted together by means of the sockets of the protrusions. After lamination, a stress-adjusting layer 13 with stronger adhesion is obtained. The morphology, number and arrangement of the protrusions are not limited.

[0044] In another embodiment, at least two layers of the stress-adjusting layer 13 include protrusions, which can ensure the interlocking between adjacent layers and also obtain a stress-adjusting layer 13 with strong adhesion. The shape, number and arrangement of the protrusions are not limited.

[0045] According to one embodiment of this application, please refer to Figure 2 The stress adjustment layer 13 can be located in the first bending region 102, the bending region 102 and the second bending region 102, which simplifies the process complexity and helps to adjust the device functional layer 12 to the stress neutral region 102a.

[0046] According to one embodiment of this application, please refer to Figure 4 The stress-adjusting layer 13 may be located only in the bending region 102, or the stress-adjusting layer 13 may be located in the bending region 102 and partially overlap with at least one of the first non-bending region 101 and the second non-bending region 103, which is beneficial to reducing material costs.

[0047] According to one embodiment of this application, the stress-adjusting layer 13 is made of at least one of polyolefin elastomer and polyethylene terephthalate. This polymer material can provide higher water resistance and ensure the reliability of the device.

[0048] According to one embodiment of this application, please refer to Figure 1The device functional layer 12 also includes a bottom electrode 121, a hole transport layer 122, an electron transport layer 124, and a top electrode 125. The bottom electrode 121 is attached to one side of the substrate 11. The quantum dot absorption layer 123 is disposed between the hole transport layer 122 and the electron transport layer 124. Specifically, the working principle of the quantum dot flexible detector 10 is as follows: external incident light penetrates into the top electrode 125, and the light is captured by the quantum absorption layer 123. The quantum dot absorption layer 123 is excited by photons to generate electron-hole excitons, which are then transported by the electron transport layer 124. The stepped energy difference formed by the hole transport layer 122 enables effective exciton dissociation. Photogenerated electrons are transported to the bottom electrode 121 via the electron transport layer 124, and photogenerated holes are transported to the top electrode 125 via the nickel oxide hole transport layer 122. Under the action of an applied bias voltage, photogenerated electrons are formed, enabling the normal operation of the quantum dot flexible detector 10. It should be noted that silicon-based CMOS readout circuits set in the first non-bending region 101 and the second non-bending region 103 can collect the photocurrent signals of each pixel and complete the signal processing and output to realize photoelectric detection and imaging.

[0049] In one embodiment, the quantum dot flexible detector 10 of this application can be an inverted structure. Specifically, the inverted structure is designed as follows: a hole transport layer 122 is disposed on the side of the bottom electrode 121 away from the substrate 11, an electron transport layer 124 is disposed on the side of the hole transport layer 122 away from the bottom electrode 121, and a top electrode 125 is disposed on the side of the electron transport layer 124 away from the hole transport layer 122. The inverted structure quantum dot flexible detector 10 has less interface damage in the process route and higher product reliability.

[0050] In another implementation, please refer to Figure 8 The quantum dot flexible detector 10 in this application can be an upright structure. The specific structure of the upright structure is designed as follows: the electron transport layer 124 is disposed on the side of the bottom electrode 121 away from the substrate 11, the hole transport layer 122 is disposed on the side of the electron transport layer 124 away from the bottom electrode 121, and the top electrode 125 is disposed on the side of the hole transport layer 122 away from the electron transport layer 124, which can be adapted to different product requirements.

[0051] According to one embodiment of this application, the bottom electrode 121 can be prepared by at least one of thermal evaporation (TE), electron beam evaporation (EB), magnetron sputtering (MS), or printing. The process is mature and can be adapted to the process requirements of the detector.

[0052] According to one embodiment of this application, the material of the bottom electrode 121 is at least one of indium tin oxide (ITO) and fluorine-doped tin oxide (FTO). ITO has high visible light transmittance and excellent conductivity, which can effectively reduce the series resistance of the device. FTO has strong corrosion resistance and wide material versatility, which is conducive to reducing the material cost of the device.

[0053] According to one embodiment of this application, the thickness of the bottom electrode 121 is in the range of 100 to 500 nm, wherein the thickness of the bottom electrode 121 includes, but is not limited to, 100 nm, 230 nm, 300 nm, 420 nm, and 500 nm, which can meet the device's requirements for the conductivity of the bottom electrode 121.

[0054] According to one embodiment of this application, the hole transport layer 122 can be prepared by magnetron sputtering. This process deposits a dense and uniform film with low surface roughness, which can ensure the reliability of the device.

[0055] According to one embodiment of this application, the thickness of the hole transport layer 122 is in the range of 10 to 100 nm. The thickness of the hole transport layer 122 includes, but is not limited to, 10 nm, 35 nm, 50 nm, 75 nm, and 100 nm. The hole transport layer 122 can collect photogenerated holes from the quantum dot absorption layer 123 and transport them to the top electrode 125. The limitation on the thickness can avoid the risk of hole recombination loss and ensure the continuity of the film.

[0056] According to one embodiment of this application, the hole transport layer 122 is made of nickel oxide (NiO). X ), ethylenedithiol ligand lead sulfide quantum dots (PbS-EDT), can efficiently extract photogenerated holes to meet the process requirements of devices.

[0057] According to one embodiment of this application, the quantum dot absorption layer 123 can be prepared by at least one of spin coating (SC), slot coating (SDC), printing (SP), and inkjet printing (IJP), and a uniform and flat film surface of the quantum dot absorption layer 123 can be obtained.

[0058] According to one embodiment of this application, the thickness of the quantum dot absorption layer 123 is in the range of 10 to 100 nm, wherein the thickness of the quantum dot absorption layer 123 includes, but is not limited to, 10 nm, 37 nm, 50 nm, 67 nm, and 100 nm, which can ensure that a sufficient amount of quantum dots can capture photons.

[0059] According to one embodiment of the application, the quantum dot absorption layer 123 is made of lead sulfide quantum dots. The unique quantum confinement effect of lead sulfide allows the band gap to be precisely controlled by the particle size, achieving absorption coverage of short-wave infrared and even a wider spectral range. Moreover, quantum dot materials can be solution processed and are compatible with silicon-based CMOS processes, reducing process costs.

[0060] According to one embodiment of this application, the thickness of the electron transport layer 124 is in the range of 15 to 100 nm. The thickness of the electron transport layer 124 includes, but is not limited to, 15 nm, 30 nm, 55 nm, 78 nm, and 100 nm. The electron transport layer 124 can efficiently extract photogenerated electrons generated by the quantum dot absorption layer 123 and transport them to the bottom electrode 121. Limiting the thickness of the electron transport layer 124 can ensure the continuous extension of the film.

[0061] According to one embodiment of this application, the electron transport layer 124 is prepared by at least one of vapor deposition (TE) and atomic vapor deposition (ALD), which can form a dense and uniform film layer to meet process requirements.

[0062] According to one embodiment of this application, the electron transport layer 124 is made of at least one of tin oxide (SnO2), zinc oxide (ZnO), and fullerene (C60), which is beneficial to improve photoelectric conversion efficiency and extend device life. Specifically, it can be illustrated as follows: In the fabrication process of the inverted quantum dot flexible detector 10, the top electrode 125 needs to be fabricated by sputtering material at the interface layer. The top electrode 125 is disposed on the side of the electron transport layer 124 away from the hole transport layer 122. During the sputtering process, the electron transport layer 124 plays a blocking role. Choosing tin oxide (SnO2) as the material of the electron transport layer 124 can achieve less interface damage and ensure product yield.

[0063] According to one embodiment of this application, the top electrode 125 is prepared by magnetron sputtering to obtain a dense, uniform and continuous top electrode 125, ensuring the normal operation of the device.

[0064] According to one embodiment of this application, the thickness of the top electrode 125 is in the range of 80 to 300 nm, wherein the thickness of the top electrode 125 includes, but is not limited to, 80 nm, 130 nm, 200 nm, 210 nm, and 300 nm, to meet the process requirements.

[0065] According to one embodiment of this application, the top electrode 125 is made of at least one of indium tin oxide (ITO) and indium zinc oxide (IZO). ITO and IZO have both high light transmittance and excellent conductivity, which is beneficial for external light to enter the quantum dot flexible detector 10 and reduce the power consumption of the detector.

[0066] According to one embodiment of this application, at least one of the bottom electrode 121, hole transport layer 122, quantum dot absorption layer 123, electron transport layer 124, and top electrode 125 is a stress-neutral region 1021, wherein the stress-neutral region 1021 is a position where the mechanical stress is theoretically zero. This setting can improve the bending resistance of the device and improve the long-term operational stability of the device.

[0067] Furthermore, the quantum dot absorption layer 123 is a stress-neutral region 1021. The quantum dot absorption layer 123 is located close to the central film layer in the functional layer 12 of the device. Since the quantum dot absorption layer 123 is a stress-neutral region 1021, after the device is bent, the top electrode 125 and the hole transport layer 122 are subjected to tensile stress, while the bottom electrode 121 and the electron transport layer 124 are subjected to compressive stress. This design can effectively optimize the bending resistance of the device.

[0068] According to one embodiment of this application, the quantum dot flexible detector 10 further includes a substrate 11, which serves as a support and can provide an operating platform for subsequent film layers.

[0069] According to one embodiment of this application, the substrate 11 is made of at least one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), colorless transparent polyimide (CPI), and polyimide (PI), which can meet the process requirements.

[0070] According to one embodiment of this application, the thickness of the substrate 11 is in the range of 10 to 200 μm, wherein the thickness of the substrate 11 includes, but is not limited to, 10 μm, 80 μm, 100 μm, 120 μm, and 200 μm, which can ensure the mechanical strength of the device.

[0071] Secondly, according to one embodiment of this application, please refer to... Figure 9 This application provides a method for fabricating a quantum dot flexible detector 10. The quantum dot flexible detector 10 includes a bending region 102, and the bending region 102 includes a stress neutral region 1021. S101, Provide a substrate 11; The substrate 11 serves as a support, providing an operating platform for subsequent film preparation.

[0072] S102. Provide a device functional layer 12, which is disposed on one side of the substrate 11 and includes a quantum dot absorption layer 123. The device functional layer 12 also includes a bottom electrode 121, a hole transport layer 122, an electron transport layer 124, and a top electrode 125. The bottom electrode 121 is attached to one side of the substrate 11. The quantum dot absorption layer 123 is disposed between the hole transport layer 122 and the electron transport layer 124. Specifically, the working principle of the quantum dot flexible detector 10 is as follows: external incident light penetrates into the top electrode 125, and the light is captured by the quantum absorption layer 123. The quantum dot absorption layer 123 is excited by photons to generate electron-hole excitons, which are then transported by the electron transport layer 124 and the top electrode 125. The stepped energy difference formed by the hole transport layer 122 enables effective exciton dissociation. Photogenerated electrons are transported to the bottom electrode 121 via the electron transport layer 124, and photogenerated holes are transported to the top electrode 125 via the nickel oxide hole transport layer 122. Under the action of an applied bias voltage, photogenerated electrons are formed, enabling the normal operation of the quantum dot flexible detector 10. It should be noted that silicon-based CMOS readout circuits set in the first non-bending region 101 and the second non-bending region 103 can collect the photocurrent signals of each pixel and complete signal processing and output to achieve photoelectric detection and imaging; please refer to Figure 1 The quantum dot flexible detector 10 in this application can be an inverted structure. Specifically, the inverted structure is designed as follows: the hole transport layer 122 is disposed on the side of the bottom electrode 121 facing away from the substrate 11, the electron transport layer 124 is disposed on the side of the hole transport layer 122 facing away from the bottom electrode 121, and the top electrode 125 is disposed on the side of the electron transport layer 124 facing away from the hole transport layer 122. The inverted structure of the quantum dot flexible detector 10 is beneficial for mass production and has high device reliability. Alternatively, the quantum dot flexible detector 10 in this application can be a normal structure. Specifically, the normal structure is designed as follows: the electron transport layer 124 is disposed on the side of the bottom electrode 121 facing away from the substrate 11, the hole transport layer 122 is disposed on the side of the electron transport layer 124 facing away from the bottom electrode 121, and the top electrode 125 is disposed on the side of the hole transport layer 122 facing away from the electron transport layer 124, which can adapt to different product requirements.

[0073] S103. A stress adjustment layer 13 is provided. The stress adjustment layer 13 is disposed on the side of the device functional layer 12 away from the substrate 11. The stress adjustment layer 13 regulates the device functional layer 12 to be located in the stress neutral region 1021. By adjusting the thickness of the stress-adjusting layer 13, the functional layer 12 of the device is controlled in the stress-neutral region 1021, which effectively improves the bending resistance of the device and enhances the long-term operational stability of the device.

[0074] In summary, this application provides a quantum dot flexible detector 10 and its fabrication method. The quantum dot flexible detector 10 includes a substrate 11, a device functional layer 12, and a stress adjustment layer 13. The device functional layer 12 is located on one side of the substrate 11, and the stress adjustment layer 13 is disposed on the side of the device functional layer 12 away from the substrate 11. By setting the stress adjustment layer 13, the device functional layer 12 can be adjusted to the stress neutral region 1021, which effectively improves the bending resistance of the device and solves the problem that the quantum dot flexible detector 10 is difficult to adapt to curved surface application scenarios.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A flexible quantum dot detector, the flexible quantum dot detector comprising a bending region, the bending region comprising a stress-neutral region, characterized in that, include, Substrate; A device functional layer is disposed on one side of the substrate, and the device functional layer includes a quantum dot absorption layer; A stress-adjusting layer is disposed on the side of the device functional layer opposite to the substrate, and the stress-adjusting layer regulates the device functional layer to be located in the stress neutral region.

2. The quantum dot flexible detector according to claim 1, characterized in that, The stress-adjusting layer has the same thickness as the substrate; Preferably, the thickness of the stress-adjusting layer is in the range of 10 to 200 μm.

3. The quantum dot flexible detector according to claim 1, characterized in that, The edges of the substrate and the stress-adjusting layer are in close contact to form an inner packaging containment space, and the device functional layer is located within the inner packaging containment space.

4. The quantum dot flexible detector according to claim 1, characterized in that, The stress-adjusting layer includes at least a first layer and a second layer; Preferably, the materials of the first layer and the second layer are different; Preferably, the second layer is located between adjacent first layers, and the first layer has one more layer than the second layer; Preferably, the first layer and the second layer are stacked alternately, and the number of layers in the second layer is equal to the number of layers in the first layer; Preferably, the surface of the stress-adjusting layer facing away from the substrate includes at least one groove; Preferably, the boundary between the first layer and the second layer is complementary and interlocked.

5. The quantum dot flexible detector according to claim 1, characterized in that, The stress-adjusting layer is made of at least one of polyolefin elastomer and polyethylene terephthalate.

6. The quantum dot flexible detector according to claim 1, characterized in that, The functional layer of the device also includes a bottom electrode, a hole transport layer, an electron transport layer, and a top electrode. The bottom electrode is attached to one side of the substrate, and the quantum dot absorption layer is disposed between the hole transport layer and the electron transport layer. Preferably, the hole transport layer is disposed on the side of the bottom electrode opposite to the substrate, the electron transport layer is disposed on the side of the hole transport layer opposite to the bottom electrode, and the top electrode is disposed on the side of the electron transport layer opposite to the hole transport layer. Preferably, the electron transport layer is disposed on the side of the bottom electrode opposite to the substrate, the hole transport layer is disposed on the side of the electron transport layer opposite to the bottom electrode, and the top electrode is disposed on the side of the hole transport layer opposite to the electron transport layer.

7. The quantum dot flexible detector according to claim 6, characterized in that, At least one of the bottom electrode, the hole transport layer, the quantum dot absorption layer, and the electron transport layer is the stress neutral region; Preferably, the quantum dot absorption layer is the stress-neutral region.

8. The quantum dot flexible detector according to claim 1, characterized in that, The quantum dot absorption layer is made of lead sulfide quantum dots-ethylenedithiol.

9. The quantum dot flexible detector according to claim 1, characterized in that, The thickness of the quantum dot absorption layer ranges from 10 to 100 nm.

10. A method for fabricating a flexible quantum dot detector, the flexible quantum dot detector comprising a bending region, the bending region comprising a stress-neutral region, characterized in that, include, Provide a substrate; A device functional layer is provided, the device functional layer being disposed on one side of the substrate, the device functional layer including a quantum dot absorption layer; A stress-adjusting layer is provided, the stress-adjusting layer being disposed on the side of the device functional layer opposite to the substrate, the stress-adjusting layer regulating the device functional layer to be located in the stress neutral region.

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