Colloidal quantum dot focal plane chip and preparation method thereof

Abstract

The invention relates to the technical field of photoelectric imaging, and discloses a colloidal quantum dot focal plane chip and a preparation method thereof, and the preparation method comprises the steps: providing a substrate; forming a plurality of electrodes arranged in an array on the surface of one side of the substrate; forming a plurality of pixel isolation layers on the surface of one side of the substrate; the plurality of pixel isolation layers are arranged at intervals in a first direction and extend along a second direction; the plurality of electrodes and the plurality of pixel isolation layers jointly enclose a plurality of pixel regions arranged in an array, and the pixel regions are exposed out of the surface of the substrate; forming a colloidal quantum dot photosensitive film on the surface of one side of the substrate, wherein the colloidal quantum dot photosensitive film covers the surface of the substrate exposed in the pixel region and covers the pixel isolation layer and the electrode; the colloidal quantum dot photosensitive film comprises a photosensitive area and a non-photosensitive area; the photosensitive area is located in a pixel area on the surface of the substrate; the non-photosensitive area is located on the surface of the side, back to the substrate, of the pixel isolation layer. According to the invention, lossless isolation between pixels can be realized, the photoelectric property, the stability and the reliability of a chip are improved, and the process cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic imaging, and particularly relates to a colloidal quantum dot focal plane chip and a preparation method thereof. Background Art

[0002] Infrared focal plane chips based on colloidal quantum dot materials have become one of the important members of infrared imaging chips due to their advantages such as low process difficulty, low cost, and direct coupling with silicon-based readout circuits. However, since colloidal quantum dot materials are easily soluble in organic solvents and are incompatible with mature micro-nano processes, it is impossible to perform processes such as photolithography on the colloidal quantum dot material thin film. Therefore, it is difficult to achieve spatial control at the patterning level through ordinary micro-nano processing techniques, making it difficult to effectively define the photosensitive areas of focal plane pixels and unable to avoid crosstalk problems between different pixels.

[0003] In the prior art, methods for preparing colloidal quantum dot photosensitive thin films, such as inkjet printing, transfer printing, and spraying methods, can directly form multiple independent photosensitive areas in a patterned manner and achieve the purpose of spatial control of the material to a certain extent. However, these methods have low yields, high costs, and complex operations, and are not suitable for large-scale low-cost preparation of materials. In addition, there is also a scheme of first forming isolation areas between pixels and then filling the gaps with colloidal quantum dot materials. However, in this scheme, the contact and bonding between the colloidal quantum dot materials and the isolation areas are poor, which will reduce the reliability of the photosensitive areas; and when the chip works, infrared light is easily recombined by the isolation areas, which will reduce the efficiency of converting light into electricity and seriously damage the electrical properties of the photosensitive areas, resulting in poor optoelectronic performance and low reliability of the infrared focal plane chip.

[0004] Therefore, a scheme is needed to achieve non-destructive isolation between pixels of an infrared focal plane chip based on colloidal quantum dot materials. Summary of the Invention

[0005] In view of this, the present invention provides a colloidal quantum dot focal plane chip and a preparation method thereof to solve the problems that the colloidal quantum dot materials in the related art are incompatible with micro-nano processes, the cost of directly preparing patterned photosensitive areas by spraying processes is high and the processes are complex, and the bonding between the existing isolation areas and the colloidal quantum dot materials is poor, which will damage the electrical properties of the photosensitive areas, and further reduce the poor performance and low reliability of the chip.

[0006] In a first aspect, the present invention provides a preparation method of a colloidal quantum dot focal plane chip, and the preparation method includes:

[0007] Providing a substrate;

[0008] Forming a plurality of electrodes arranged in an array on one side surface of the substrate;

[0009] Form a plurality of pixel isolation layers on one side surface of the substrate; the plurality of pixel isolation layers are arranged at intervals in the first direction and extend along the second direction;

[0010] The plurality of electrodes and the plurality of pixel isolation layers jointly enclose a plurality of pixel regions arranged in an array, and the substrate surface is exposed in the pixel regions;

[0011] Form a colloidal quantum dot photosensitive thin film on one side surface of the substrate. The colloidal quantum dot photosensitive thin film covers the exposed substrate surface in the pixel regions and coats the pixel isolation layers and the electrodes; the colloidal quantum dot photosensitive thin film includes a photosensitive region and a non-photosensitive region; the photosensitive region is located in the pixel regions on the substrate surface; the non-photosensitive region is located on the surface of the pixel isolation layer facing away from the substrate.

[0012] The preparation method of the colloidal quantum dot focal plane chip provided by the present invention encloses a plurality of pixel regions arranged in an array through the plurality of electrodes and the plurality of pixel isolation layers, and then forms a colloidal quantum dot photosensitive thin film on one side surface of the substrate. The colloidal quantum dot photosensitive thin film includes a photosensitive region located in the pixel regions and a non-photosensitive region located on the surface of the pixel isolation layer. First, the pixel regions can be effectively defined by the electrodes and the pixel isolation layers, and the photosensitive region of each pixel can be effectively defined as the functional region of the chip through the non-photosensitive region on the surface of the pixel isolation layer. There is no need to perform micro-nano processes on the colloidal quantum dot photosensitive thin film, which can simplify the process flow and reduce the process cost; second, the colloidal quantum dot photosensitive thin film is a film that covers the entire surface of the chip, and the bonding property between the colloidal quantum dot photosensitive thin film and the pixel isolation layers and the electrodes is strong, which can improve the stability and reliability of the chip; third, the non-photosensitive region used to isolate the photosensitive regions belongs to a part of the colloidal quantum dot photosensitive thin film and does not affect the electrical properties of the photosensitive regions, which can limit the crosstalk between pixels and achieve lossless isolation between pixels of the focal plane chip, thereby improving the optoelectronic performance and reliability of the infrared focal plane chip. Therefore, the preparation method of the colloidal quantum dot focal plane chip provided by the present invention can limit the crosstalk between pixels, achieve lossless isolation between pixels of the focal plane chip, thereby improving the optoelectronic performance and reliability of the infrared focal plane chip, and at the same time can simplify the process flow, reduce the process cost, and improve the stability of the chip.

[0013] In an optional embodiment, the first direction is perpendicular to the second direction; the plurality of pixel isolation layers separate the plurality of electrodes into a plurality of electrode groups arranged at intervals in the first direction, and each electrode group includes a plurality of electrodes arranged at intervals in the second direction;

[0014] The electrode groups and the pixel isolation layers are alternately arranged;

[0015] In the second direction, the electrodes and the pixel regions are alternately arranged.

[0016] In an optional embodiment, the colloidal quantum dot photosensitive thin film further includes an electrode region, and the electrode region is located on the surface of the electrode facing away from the substrate;

[0017] In the second direction, the electrode regions and the photosensitive regions are alternately arranged.

[0018] In an optional embodiment, the substrate surface is a hydrophilic surface;

[0019] The pixel isolation layer is a metal oxide thin film, and the surface of the metal oxide thin film is a hydrophobic surface;

[0020] The steps of forming a colloidal quantum dot photosensitive thin film on the substrate surface, with the colloidal quantum dot photosensitive thin film covering the pixel region and coating the pixel isolation layer and the electrodes, include:

[0021] Prepare a colloidal quantum dot material solution, which includes a colloidal quantum dot material and a solvent; the colloidal quantum dot material is suitable for forming a photosensitive region on the hydrophilic surface and a non-photosensitive region on the hydrophobic surface;

[0022] Spin-coat the colloidal quantum dot material solution onto the exposed substrate surface of the pixel region, the surface of the pixel isolation layer, and the surface of the electrodes;

[0023] Heat the colloidal quantum dot material solution in an inert gas atmosphere to form a colloidal quantum dot photosensitive thin film;

[0024] Wherein, the colloidal quantum dot material forms a non-photosensitive region on the surface of the pixel isolation layer facing away from the substrate in an amorphous manner, and the colloidal quantum dot material forms a photosensitive region in the pixel region on the substrate surface in a crystalline manner.

[0025] The method for preparing a colloidal quantum dot focal plane chip provided by the present invention utilizes the dependence of the film-forming crystallization quality of the colloidal quantum dot material on the substrate surface energy. By introducing a metal oxide thin film as the pixel isolation layer to pattern the substrate surface energy, the colloidal quantum dot material forms a non-photosensitive region on the hydrophilic surface of the pixel isolation layer and a photosensitive region on the hydrophilic surface of the substrate in the pixel region. It is possible to reduce the mobility of carriers in the colloidal quantum dot thin film in the non-photosensitive region on the surface of the pixel isolation layer without affecting the crystallization quality of the colloidal quantum dot thin film in the photosensitive region, thereby restricting crosstalk between pixels, effectively defining the photosensitive region, achieving lossless isolation between pixels of the focal plane chip, and further improving the optoelectronic performance and reliability of the infrared focal plane chip.

[0026] In an optional embodiment, the step of heating the colloidal quantum dot material solution in an inert gas atmosphere to form a colloidal quantum dot photosensitive thin film includes:

[0027] Heat the colloidal quantum dot material solution in an inert gas atmosphere to a first temperature and maintain it for a first time to completely remove the solvent and form a colloidal quantum dot photosensitive thin film;

[0028] The first temperature is 80°C to 200°C;

[0029] The first time is 10 mins to 60 mins.

[0030] In an alternative embodiment, the colloidal quantum dot material comprises quantum dots and perovskite ligands;

[0031] In the colloidal quantum dot photosensitive film, the perovskite ligands surround the quantum dots;

[0032] Among them, the photosensitive region has a crystal structure, and the quantum dots in the photosensitive region are arranged in an array, and the perovskite ligands uniformly surround the quantum dots;

[0033] The non-photosensitive region has an amorphous structure, the quantum dots in the non-photosensitive region are irregularly arranged, and the perovskite ligands do not uniformly surround the quantum dots;

[0034] The carrier mobility of the non-photosensitive region is less than that of the photosensitive region.

[0035] The method for preparing the colloidal quantum dot focal plane chip provided by the present invention utilizes the dependence of the crystallization and film formation of the colloidal quantum dot material on the hydrophilicity of the substrate. By constructing a patterned metal oxide distribution, the colloidal quantum dot material forms a photosensitive region with a crystal structure in a crystalline manner on the hydrophilic surface, and forms a non-photosensitive region with an amorphous structure in a non-crystalline manner on the hydrophobic surface, so that the carrier mobility of the non-photosensitive region is less than that of the photosensitive region. Without affecting the crystallization quality of the colloidal quantum dot film in the photosensitive region, the carrier mobility in the colloidal quantum dot film in the non-photosensitive region on the surface of the pixel isolation layer can be reduced, thereby restricting crosstalk between pixels, effectively defining the photosensitive region, realizing lossless isolation between the pixels of the focal plane chip, and further improving the optoelectronic performance and reliability of the infrared focal plane chip.

[0036] In an alternative embodiment, the quantum dots are HgSe quantum dots;

[0037] The perovskite ligands are MAPbI3 perovskite ligands.

[0038] In an alternative embodiment, the carrier mobility of the photosensitive region is greater than 0.6 cm 2 / (V·s);

[0039] The carrier mobility of the non-photosensitive region is less than 0.001 cm 2 / (V·s).

[0040] The preparation method of the colloidal quantum dot focal plane chip provided by the present invention is such that the colloidal quantum dot material forms a non-photosensitive region with a relatively low carrier mobility on the hydrophilic surface of the pixel isolation layer, and forms a photosensitive region with a relatively high carrier mobility on the hydrophilic surface of the substrate in the pixel region, enabling the photosensitive region to be used as the functional region of the chip for the photoelectric conversion of infrared light, and using the pixel isolation layer and the non-photosensitive region as the isolation region between the photosensitive regions of adjacent pixels to achieve lossless isolation of multiple pixels.

[0041] In an optional embodiment, the thickness of the electrode is 20 nm to 100 nm;

[0042] The thickness of the pixel isolation layer is 20 nm to 100 nm;

[0043] The thickness of the photosensitive region is 150 nm to 500 nm;

[0044] The width of the pixel region in the first direction is 5 μm to 200 μm;

[0045] The width of the electrode in the first direction is 5 μm to 200 μm;

[0046] The ratio of the width of the electrode in the second direction to the width of the pixel region in the second direction is 1:8 to 1:4;

[0047] The width of the pixel isolation layer in the first direction is 5 μm to 200 μm.

[0048] In an optional embodiment, the material of the substrate is silicon, silicon dioxide or a silicon-based readout circuit;

[0049] The material of the metal oxide thin film is hafnium oxide, titanium oxide or aluminum oxide;

[0050] The material of the electrode is gold or titanium gold.

[0051] In a second aspect, the present invention provides a colloidal quantum dot focal plane chip, which includes:

[0052] A substrate;

[0053] A plurality of electrodes arranged in an array, located on one side surface of the substrate;

[0054] A plurality of pixel isolation layers, located on one side surface of the substrate; the plurality of pixel isolation layers are arranged at intervals in the first direction and extend along the second direction; the plurality of electrodes and the plurality of pixel isolation layers jointly enclose a plurality of pixel regions arranged in an array;

[0055] A colloidal quantum dot photosensitive thin film, located on one side surface of the substrate, and the colloidal quantum dot photosensitive thin film also covers the pixel isolation layer and the electrode; the colloidal quantum dot photosensitive thin film includes a photosensitive region and a non-photosensitive region; the photosensitive region is located in the pixel region on the surface of the substrate; the non-photosensitive region is located on the side surface of the pixel isolation layer facing away from the substrate.

[0056] In an alternative embodiment, the first direction is perpendicular to the second direction; a plurality of pixel isolation layers space a plurality of electrodes into a plurality of electrode groups arranged at intervals in the first direction, and each electrode group includes a plurality of electrodes arranged at intervals in the second direction;

[0057] The electrode groups and the pixel isolation layers are alternately arranged;

[0058] In the second direction, the electrodes and the pixel regions are alternately arranged;

[0059] The colloidal quantum dot photosensitive film further includes an electrode region, and the electrode region is located on the surface of the electrode on the side facing away from the substrate;

[0060] In the second direction, the electrode region and the photosensitive region are alternately arranged;

[0061] The carrier mobility of the non-photosensitive region is less than that of the photosensitive region.

[0062] For the colloidal quantum dot focal plane chip provided by the present invention, on the one hand, the colloidal quantum dot photosensitive film is a film that entirely covers the chip surface, and the binding property between the colloidal quantum dot photosensitive film and the pixel isolation layer and the electrodes is strong, which can improve the stability and reliability of the chip; on the other hand, the non-photosensitive region used to isolate the photosensitive region is part of the colloidal quantum dot photosensitive film, which will not affect the electrical properties of the photosensitive region, can limit the crosstalk between pixels, achieve lossless isolation between pixels of the focal plane chip, and further improve the optoelectronic performance and reliability of the infrared focal plane chip. Therefore, the colloidal quantum dot focal plane chip provided by the present invention can limit the crosstalk between pixels, achieve lossless isolation between pixels of the focal plane chip, and further improve the optoelectronic performance, reliability and stability of the infrared focal plane chip. Description of the Drawings

[0063] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the related art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0064] Figure 1 is a schematic flowchart of a preparation method of a colloidal quantum dot focal plane chip according to an embodiment of the present invention.

[0065] Figure 2A is a schematic top view of the structure of forming electrodes in a preparation method of a colloidal quantum dot focal plane chip according to an embodiment of the present invention.

[0066] Figure 2BIn the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 2A Schematic cross-sectional view on the BB plane.

[0067] Figure 2C In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 2A Schematic cross-sectional view on the CC plane.

[0068] Figure 3A Schematic top view of the structure of the pixel isolation layer formed in the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention.

[0069] Figure 3B In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 3A Schematic cross-sectional view on the BB plane.

[0070] Figure 3C In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 3A Schematic cross-sectional view on the CC plane.

[0071] Figure 3D In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 3A Schematic cross-sectional view on the DD plane.

[0072] Figure 4A Schematic top view of the structure of the pixel isolation layer formed in the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention.

[0073] Figure 4B In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 4A Schematic cross-sectional view on the BB plane.

[0074] Figure 4C In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 4A Schematic cross-sectional view on the CC plane.

[0075] Figure 4D In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 4A Schematic cross-sectional view on the DD plane.

[0076] Figure 4E In the method for preparing a colloidal quantum dot focal plane chip according to an embodiment of the present invention Figure 4B Schematic cross-sectional view on the AA plane.

[0077] Figure 5It is a potential schematic diagram of a colloidal quantum dot focal plane chip according to an embodiment of the present invention.

[0078] Figure 6 It is a specific process schematic diagram of a preparation method of a colloidal quantum dot focal plane chip according to an embodiment of the present invention.

[0079] Reference numerals:

[0080] 10. Substrate; 20. Electrode; 30. Pixel isolation layer; 40. Colloidal quantum dot photosensitive thin film; 41. Photosensitive region; 42. Non-photosensitive region; 43. Electrode region; 100. Pixel region. Detailed implementation manners

[0081] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the convenience of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0082] In the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concepts of the present invention. Various structural schematic diagrams according to embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, and for the purpose of clear expression, some details are enlarged, and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are only exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element can be directly on the other layer / element, or there can be an intermediate layer / element between them. Additionally, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element can be "under" the other layer / element.

[0083] Infrared focal plane chips based on colloidal quantum dot materials have become one of the important members of infrared imaging chips due to their advantages such as low process difficulty, low cost, and direct coupling with silicon-based readout circuits. However, since colloidal quantum dot materials are easily soluble in organic solvents and are incompatible with mature micro-nano processes, it is impossible to perform lithography and other process treatments on colloidal quantum dot material thin films. Therefore, it is difficult to achieve spatial control at the patterning level through ordinary micro-nano processing technologies, making it difficult to effectively define the photosensitive regions of focal plane pixels and impossible to avoid crosstalk problems between different pixels.

[0084] In the prior art, methods for preparing colloidal quantum dot photosensitive films, such as inkjet printing, transfer printing, and spraying methods, can directly form multiple independent photosensitive regions in a patterned manner and achieve the purpose of spatial control of materials to a certain extent. However, these methods have low yields, high costs, and complex operations, and are not suitable for low-cost large-scale preparation of materials. In addition, there is also a scheme in which an isolation region is first formed between pixels, and then the voids are filled with colloidal quantum dot materials. However, in this scheme, the contact and bonding between the colloidal quantum dot materials and the isolation region are poor, which will reduce the reliability of the photosensitive region; and when the chip is working, infrared light is easily recombined by the isolation region, which will reduce the efficiency of converting light into electricity and seriously damage the electrical properties of the photosensitive region, resulting in poor optoelectronic performance and low reliability of the infrared focal plane chip.

[0085] Therefore, a scheme is needed to achieve non-destructive isolation between pixels of an infrared focal plane chip based on colloidal quantum dot materials.

[0086] As Figure 1 shown, this embodiment provides a method for preparing a colloidal quantum dot focal plane chip, and the preparation method includes but is not limited to steps S101 to S104.

[0087] Step S101, providing a substrate 10;

[0088] Step S102, forming a plurality of electrodes 20 arranged in an array on one surface of the substrate 10, as Figure 2A , Figure 2B and Figure 2C shown.

[0089] Specifically, as Figure 2A is the top view of the structure for forming a plurality of electrodes 20, Figure 2B is Figure 2A the cross-sectional view on the BB plane, Figure 2C is Figure 2A the cross-sectional view on the CC plane.

[0090] Step S103, forming a plurality of pixel isolation layers 30 on one surface of the substrate 10; the plurality of pixel isolation layers 30 are arranged at intervals in a first direction and extend in a second direction; the plurality of electrodes 20 and the plurality of pixel isolation layers 30 jointly enclose a plurality of pixel regions 100 arranged in an array, and the surface of the substrate 10 is exposed in the pixel regions 100, as Figure 3A , Figure 3B , Figure 3C and Figure 3D shown.

[0091] Specifically, the first direction is the x direction in Figure 3A , and the second direction is the y direction in Figure 3A . As Figure 3AA top view of the structure for forming a plurality of pixel isolation layers 30 Figure 3B is Figure 3A a schematic cross-sectional view on the BB plane Figure 3C is Figure 3A a schematic cross-sectional view on the CC plane Figure 3D is Figure 3A a schematic cross-sectional view on the DD plane

[0092] Step S104: Form a colloidal quantum dot photosensitive film 40 on one surface of the substrate 10. The colloidal quantum dot photosensitive film 40 covers the exposed surface of the substrate 10 in the pixel region 100 and coats the pixel isolation layer 30 and the electrode 20. The colloidal quantum dot photosensitive film 40 includes a photosensitive region 41 and a non-photosensitive region 42. The photosensitive region 41 is located in the pixel region 100 on the surface of the substrate 10. The non-photosensitive region 42 is located on the surface of the pixel isolation layer 30 facing away from the substrate 10, as shown in Figure 4A , Figure 4B , Figure 4C , Figure 4D and Figure 4E shown

[0093] Specifically, as Figure 4A a top view of the structure for forming the colloidal quantum dot photosensitive film 40 Figure 4B is Figure 4A a schematic cross-sectional view on the BB plane Figure 4C is Figure 4A a schematic cross-sectional view on the CC plane Figure 4D is Figure 4A a schematic cross-sectional view on the DD plane Figure 4E is Figure 4B a schematic cross-sectional view on the AA plane

[0094] The preparation method of the colloidal quantum dot focal plane chip provided by this embodiment encloses a plurality of pixel regions arranged in an array through a plurality of electrodes and a plurality of pixel isolation layers, and then forms a colloidal quantum dot photosensitive film on one surface of the substrate. The colloidal quantum dot photosensitive film includes a photosensitive region located in the pixel region and a non-photosensitive region located on the surface of the pixel isolation layer. First, the pixel regions can be effectively defined by the electrodes and the pixel isolation layers, and the photosensitive region of each pixel can be effectively defined as the functional region of the chip through the non-photosensitive region on the surface of the pixel isolation layer. There is no need to perform micro-nano processes on the colloidal quantum dot photosensitive film, which can simplify the process flow and reduce the process cost. Second, the colloidal quantum dot photosensitive film is a film that covers the entire surface of the chip, and the binding property between the colloidal quantum dot photosensitive film and the pixel isolation layer and the electrodes is strong, which can improve the stability and reliability of the chip. Third, the non-photosensitive region used to isolate the photosensitive region is a part of the colloidal quantum dot photosensitive film, which will not affect the electrical properties of the photosensitive region, can limit the crosstalk between pixels, achieve lossless isolation between pixels of the focal plane chip, and further improve the optoelectronic performance and reliability of the infrared focal plane chip. Therefore, the preparation method of the colloidal quantum dot focal plane chip provided by this embodiment can limit the crosstalk between pixels, achieve lossless isolation between pixels of the focal plane chip, and further improve the optoelectronic performance and reliability of the infrared focal plane chip. At the same time, it can simplify the process flow, reduce the process cost, and improve the stability of the chip.

[0095] In some alternative embodiments, the first direction is perpendicular to the second direction; the plurality of pixel isolation layers 30 separate the plurality of electrodes 20 into a plurality of electrode groups arranged at intervals in the first direction, and each electrode group includes a plurality of electrodes 20 arranged at intervals in the second direction;

[0096] The electrode groups and the pixel isolation layers 30 are alternately arranged;

[0097] In the second direction, the electrodes 20 and the pixel regions 100 are alternately arranged.

[0098] During specific implementation, a plurality of pixel regions 100 arranged in an array are defined jointly by the electrodes 20 and the pixel isolation layers 30, and adjacent pixel regions 100 are separated by the electrodes 20 or the pixel isolation layers 30.

[0099] In some alternative embodiments, the colloidal quantum dot photosensitive film 40 further includes an electrode region 43, and the electrode region 43 is located on the surface of the electrode 20 facing away from the substrate 10;

[0100] In the second direction, the electrode region 43 and the photosensitive region 41 are alternately arranged.

[0101] In specific implementation, the photosensitive region 41 serves as the functional region of the chip, and adjacent photosensitive regions 41 are separated by the electrode region 43 and the non-photosensitive region 42. The finally formed colloidal quantum dot focal plane chip includes a plurality of pixels distributed in an array, and each pixel includes a photosensitive region 41; adjacent pixels are separated by the pixel isolation layer 30 and the non-photosensitive region 42, as well as the electrode 20 and the electrode region 43.

[0102] When the colloidal quantum dot focal plane chip is working, first, since the pixel isolation layer 30 and the non-photosensitive region 42 are electrically isolated and the carrier mobility is very low, the separation of the photosensitive regions 41 of two adjacent columns of pixels can be achieved; second, by applying different bias voltages to the two electrodes 20 adjacent to a single pixel respectively, a potential difference is formed between the electrode regions 43 on both sides of the pixel, thereby realizing the control of a single pixel. Specifically, by applying potentials to multiple electrodes 20 in an electrode group such that the potentials between adjacent electrodes 20 are different, the control between each pixel in a column of pixels can be achieved, thereby realizing the separation and control of the photosensitive regions 41 of multiple pixels in the focal plane chip.

[0103] In some optional implementation manners, as Figure 5 shown, the electrodes in the same row in the first direction in multiple electrode arrays are connected to the same potential; the electrodes in adjacent rows are connected to different potentials. For example, the electrodes in odd rows are simultaneously connected to the first potential V1, and the electrodes in even rows are simultaneously connected to the second potential V2, so that a potential difference is formed between the electrodes on both sides of each photosensitive region, thereby realizing the control and separation of each pixel.

[0104] In one example, the electrodes in odd rows are grounded, that is, the first potential V1 is 0V; the electrodes in even rows are connected to a bias voltage less than or equal to 10V, that is, the second potential V2 satisfies 0V < V2 ≤ 10V.

[0105] In some optional implementation manners, the surface of the substrate 10 is a hydrophilic surface;

[0106] The pixel isolation layer 30 is a metal oxide thin film, and the surface of the metal oxide thin film is a hydrophobic surface;

[0107] The steps of forming the colloidal quantum dot photosensitive thin film 40 on the surface of the substrate 10, where the colloidal quantum dot photosensitive thin film 40 covers the pixel region 100 and coats the pixel isolation layer 30 and the electrode 20, include:

[0108] Prepare a colloidal quantum dot material solution, which includes a colloidal quantum dot material and a solvent; the colloidal quantum dot material is suitable for forming a photosensitive region 41 on a hydrophilic surface and a non-photosensitive region 42 on a hydrophobic surface;

[0109] Spin-coat the colloidal quantum dot material solution on the pixel region 100 on the surface of the substrate 10, the surface of the pixel isolation layer 30, and the surface of the electrode 20;

[0110] Heat the colloidal quantum dot material solution in an inert gas atmosphere to form a colloidal quantum dot photosensitive film 40;

[0111] Among them, the colloidal quantum dot material forms a non-photosensitive region 42 on the surface of the pixel isolation layer 30 facing away from the substrate 10 in a non-crystalline manner, and the colloidal quantum dot material forms a photosensitive region 41 in the pixel region 100 on the surface of the substrate 10 in a crystalline manner.

[0112] In specific implementation, due to the strong dependence of the film-forming crystallization quality of the colloidal quantum dot material on the surface energy of the substrate, only on a hydrophilic interface can the colloidal quantum dot material form an ordered crystal structure in a crystalline manner. The film carrier mobility of this crystal structure is high and has a photoelectric conversion characteristic, which can be used as the photosensitive region of the pixel; while on a hydrophobic interface, the colloidal quantum dot material forms a disordered amorphous structure (i.e., a non-photosensitive region) in a non-crystalline manner. The film carrier mobility of the amorphous structure is low and the conductivity is poor, which can be used as the isolation region between pixels, effectively restricting the crosstalk between pixels and achieving lossless isolation between pixels. At the same time, when the non-crystalline structure photosensitive region is working, it will not recombine infrared light and will not affect the photoelectric conversion of the photosensitive region, which can improve the photoelectric conversion efficiency of the chip.

[0113] The preparation method of the colloidal quantum dot focal plane chip provided in this embodiment utilizes the dependence of the film-forming crystallization quality of the colloidal quantum dot material on the surface energy of the substrate. By introducing a metal oxide film as the pixel isolation layer to pattern the surface energy of the substrate, the colloidal quantum dot material forms a non-photosensitive region on the hydrophilic surface of the pixel isolation layer and a photosensitive region on the hydrophilic surface of the substrate in the pixel region. Without affecting the crystallization quality of the colloidal quantum dot film in the photosensitive region, the mobility of carriers in the colloidal quantum dot film in the non-photosensitive region on the surface of the pixel isolation layer can be reduced, thereby restricting the crosstalk between pixels, effectively defining the photosensitive region, achieving lossless isolation between the pixels of the focal plane chip, and further improving the photoelectric performance and reliability of the infrared focal plane chip.

[0114] In some optional implementation manners, the step of heating the colloidal quantum dot material solution in an inert gas atmosphere to form the colloidal quantum dot photosensitive film 40 includes:

[0115] Heat the colloidal quantum dot material solution to a first temperature in an inert gas atmosphere and maintain it for a first time to completely remove the solvent, so as to form the colloidal quantum dot photosensitive film 40;

[0116] The first temperature is 80°C to 200°C;

[0117] The first time is 10 mins to 60 mins.

[0118] In some alternative embodiments, the colloidal quantum dot material includes quantum dots and perovskite ligands;

[0119] In the colloidal quantum dot photosensitive thin film, the perovskite ligands surround the quantum dots;

[0120] Among them, the photosensitive region 41 has a crystal structure, and the quantum dots in the photosensitive region 41 are arranged in an array, and the perovskite ligands uniformly surround the quantum dots;

[0121] The non - photosensitive region 42 has an amorphous structure, and the quantum dots in the non - photosensitive region 42 are irregularly arranged (or randomly arranged), and the perovskite ligands do not uniformly surround the quantum dots;

[0122] The carrier mobility of the non - photosensitive region 42 is less than that of the photosensitive region 41.

[0123] Specifically, in implementation, the quantum dots in the photosensitive region 41 are arranged in a three - dimensional array, and the perovskite ligands uniformly surround the quantum dots, so that the perovskite ligands have good hole - transporting ability. Therefore, the carrier mobility of the photosensitive region 41 is relatively high. While the quantum dots in the non - photosensitive region 42 are irregularly arranged (or randomly arranged), for example, the quantum dots will irregularly aggregate, randomly disperse, etc., and there are large differences in the quantum dot distribution density in different regions, and the perovskite ligands do not uniformly surround the quantum dots or quantum dot clusters, resulting in poor hole - transporting ability of the perovskite ligands, and further resulting in a low carrier mobility of the non - photosensitive region 42 and a poor light response ability.

[0124] The preparation method of the colloidal quantum dot focal plane chip provided in this embodiment utilizes the dependence of the crystallization and film formation of the colloidal quantum dot material on the hydrophilicity of the substrate. By constructing a patterned metal oxide distribution, the colloidal quantum dot material forms a photosensitive region 41 with a crystal structure in a crystalline manner on the hydrophilic surface, and forms a non - photosensitive region 42 with an amorphous structure in a non - crystalline manner on the hydrophobic surface, so that the carrier mobility of the non - photosensitive region 42 is less than that of the photosensitive region 41. It can reduce the carrier mobility in the colloidal quantum dot thin film of the non - photosensitive region on the surface of the pixel isolation layer without affecting the crystallization quality of the colloidal quantum dot thin film in the photosensitive region, thereby restricting the crosstalk between pixels, effectively defining the photosensitive region, achieving lossless isolation between the pixels of the focal plane chip, and further improving the optoelectronic performance and reliability of the infrared focal plane chip.

[0125] In some alternative embodiments, the carrier mobility of the photosensitive region 41 is greater than 0.6 cm 2 / (V·s);

[0126] The carrier mobility of the non - photosensitive region 42 is less than 0.001 cm 2 / (V·s).

[0127] The preparation method of the colloidal quantum dot focal plane chip provided by this embodiment forms a non-photosensitive region with a relatively low carrier mobility on the hydrophilic surface of the pixel isolation layer, and forms a photosensitive region with a relatively high carrier mobility on the hydrophilic surface of the substrate in the pixel region, so that the photosensitive region is used as the functional region of the chip for the photoelectric conversion of infrared light, and the pixel isolation layer and the non-photosensitive region are used as the isolation region between the photosensitive regions of adjacent pixels to achieve lossless isolation of multiple pixels.

[0128] In some optional embodiments, the quantum dots are HgSe quantum dots;

[0129] The perovskite ligand is the MAPbI3 perovskite ligand.

[0130] Specifically, in the photosensitive region 41, the HgSe quantum dots are arranged in a regular array, and the MAPbI3 perovskite ligand uniformly surrounds the quantum dots; when light irradiates the surface, electrons and holes will be generated in the HgSe quantum dots, and the MAPbI3 perovskite ligand can bind the electrons inside the HgSe and absorb the holes. The MAPbI3 perovskite ligand has good hole transport ability, so that the carrier mobility of the photosensitive region 41 is high, which can further improve the photoelectric performance and reliability of the infrared focal plane chip.

[0131] In some optional embodiments, the thickness of the electrode 20 is 20 nm to 100 nm, such as 20 nm, 40 nm, 60 nm, 80 nm or 100 nm;

[0132] The thickness of the pixel isolation layer 30 is 20 nm to 100 nm, such as 20 nm, 40 nm, 60 nm, 80 nm or 100 nm;

[0133] The thickness of the photosensitive region 41 is 150 nm to 500 nm, such as 150 nm, 250 nm, 325 nm, 400 nm or 500 nm;

[0134] The width of the pixel region 100 in the first direction is 5 μm to 200 μm, such as 5 μm, 50 μm, 100 μm, 150 μm, or 200 μm;

[0135] The width of the electrode 20 in the first direction is 5 μm to 200 μm, such as 5 μm, 50 μm, 100 μm, 150 μm, or 200 μm;

[0136] The ratio of the width of the electrode 20 in the second direction to the width of the pixel region 100 in the second direction is 1:8 to 1:4;

[0137] The width of the pixel isolation layer 30 in the first direction is 5 μm to 200 μm.

[0138] In some alternative embodiments, the material of the substrate 10 is silicon, silicon dioxide, or a silicon-based readout circuit;

[0139] The material of the metal oxide thin film is hafnium oxide, titanium oxide, or aluminum oxide;

[0140] The material of the electrode 20 is gold or titanium gold.

[0141] In specific implementation, the surface of hafnium oxide, titanium oxide, or aluminum oxide has strong hydrophobicity. The colloidal quantum dot material can form a non-photosensitive region with a sufficiently low carrier mobility on the pixel isolation layer, improving the isolation effect of the non-photosensitive region on adjacent pixels, further restricting the crosstalk between pixels, achieving lossless isolation between pixels of the focal plane chip, and thus improving the optoelectronic performance and reliability of the colloidal quantum dot focal plane chip.

[0142] As Figure 6 shown, the present invention also provides a schematic flow chart of a preparation method for a colloidal quantum dot focal plane chip, including but not limited to steps S201 to S206.

[0143] Step S201: Provide the substrate 10; the surface of the substrate 10 is a hydrophilic surface.

[0144] In specific implementation, the material of the substrate 10 is silicon, silicon dioxide, or a silicon-based readout circuit;

[0145] Step S202: Form a plurality of electrodes 20 arranged in an array on one surface of the substrate 10, as Figure 2A , Figure 2B and Figure 2C shown.

[0146] In specific implementation, the material of the electrode 20 is gold or titanium gold; the width of the electrode 20 in the first direction is 5 μm to 200 μm; the thickness of the electrode 20 is 20 nm to 100 nm;

[0147] Step S203: Form a plurality of pixel isolation layers 30 on one surface of the substrate 10; the pixel isolation layer 30 is a metal oxide thin film, and the surface of the metal oxide thin film is a hydrophobic surface; the plurality of pixel isolation layers 30 are arranged at intervals in the first direction and extend along the second direction; the plurality of electrodes 20 and the plurality of pixel isolation layers 30 together enclose a plurality of pixel regions 100 arranged in an array, and the surface of the substrate 10 is exposed in the pixel regions 100; the plurality of pixel isolation layers 30 separate the plurality of electrodes 20 into a plurality of electrode groups arranged at intervals in the first direction, and each electrode group includes a plurality of electrodes 20 arranged at intervals in the second direction; the electrode groups and the pixel isolation layers 30 are alternately arranged; in the second direction, the electrodes 20 and the pixel regions 100 are alternately arranged, as Figure 3A , Figure 3B , Figure 3C and Figure 3D shown.

[0148] In specific implementation, the thickness of the pixel isolation layer 30 is 20 nm to 100 nm; the width of the pixel isolation layer 30 in the first direction is 5 μm to 200 μm. The width of the pixel region 100 in the first direction is 5 μm to 200 μm; the ratio of the width of the electrode 20 in the second direction to the width of the pixel region 100 in the second direction is 1:8 to 1:4; the thickness of the photosensitive region 41 is 150 nm to 500 nm; the material of the metal oxide thin film is hafnium oxide, titanium oxide or aluminum oxide.

[0149] Step S204: Prepare a colloidal quantum dot material solution, which includes a colloidal quantum dot material and a solvent; the colloidal quantum dot material is suitable for forming a photosensitive region 41 on the hydrophilic surface and a non-photosensitive region 42 on the hydrophobic surface.

[0150] Step S205: Spin-coat the colloidal quantum dot material solution on the surface of the substrate 10 exposed in the pixel region 100, the surface of the pixel isolation layer 30, and the surface of the electrode 20.

[0151] Step S206: Heat the colloidal quantum dot material solution to a first temperature and maintain it for a first period of time in an inert gas atmosphere to completely remove the solvent, so that the colloidal quantum dot material forms a colloidal quantum dot photosensitive thin film 40; the colloidal quantum dot photosensitive thin film 40 includes a photosensitive region 41 and a non-photosensitive region 42; the photosensitive region 41 is located in the pixel region 100 on the surface of the substrate 10; the non-photosensitive region 42 is located on the surface of the pixel isolation layer 30 facing away from the substrate 10; the colloidal quantum dot photosensitive thin film 40 further includes an electrode region 43, and the electrode region 43 is located on the surface of the electrode 20 facing away from the substrate 10; in the second direction, the electrode region 43 and the photosensitive region 41 are alternately arranged, as Figure 4A 、 Figure 4B 、 Figure 4C 、 Figure 4D and Figure 4E shown.

[0152] In specific implementation, the colloidal quantum dot material forms a non-photosensitive region on the surface of the pixel isolation layer facing away from the substrate in a non-crystalline manner, and the colloidal quantum dot material forms a photosensitive region in the pixel region on the surface of the substrate in a crystalline manner. The first temperature is 80 °C to 200 °C; the first period of time is 10 mins to 60 mins.

[0153] The colloidal quantum dot material includes quantum dots and perovskite ligands; in the colloidal quantum dot photosensitive film, the perovskite ligands surround the quantum dots; among them, the photosensitive region 41 has a crystal structure, and the quantum dots in the photosensitive region 41 are arranged in an array in a regular pattern, and the perovskite ligands uniformly surround the quantum dots; the non-photosensitive region 42 has an amorphous structure, the quantum dots in the non-photosensitive region 42 are arranged irregularly, and the perovskite ligands do not uniformly surround the quantum dots; the carrier mobility of the non-photosensitive region 42 is less than that of the photosensitive region 41. The carrier mobility of the photosensitive region 41 is greater than 0.6 cm 2 / (V·s); the carrier mobility of the non-photosensitive region 42 is less than 0.001 cm 2 / (V·s).

[0154] This embodiment also provides a colloidal quantum dot focal plane chip, as Figure 6 shown, the colloidal quantum dot focal plane chip includes:

[0155] A substrate 10;

[0156] A plurality of electrodes 20 arranged in an array, located on one surface of the substrate 10;

[0157] A plurality of pixel isolation layers 30, located on one surface of the substrate 10; the plurality of pixel isolation layers 30 are arranged at intervals in a first direction and extend along a second direction; the plurality of electrodes 20 and the plurality of pixel isolation layers 30 jointly enclose a plurality of pixel regions 100 arranged in an array;

[0158] A colloidal quantum dot photosensitive film 40, located on one surface of the substrate 10, and the colloidal quantum dot photosensitive film 40 also covers the pixel isolation layer 30 and the electrode 20; the colloidal quantum dot photosensitive film 40 includes a photosensitive region 41 and a non-photosensitive region 42; the photosensitive region 41 is located in the pixel region 100 on the surface of the substrate 10; the non-photosensitive region 42 is located on the surface of the pixel isolation layer 30 facing away from the substrate 10.

[0159] For the colloidal quantum dot focal plane chip provided by the present invention, on the one hand, the colloidal quantum dot photosensitive film is a film that covers the entire surface of the chip, and the binding property between the colloidal quantum dot photosensitive film and the pixel isolation layer and the electrode is relatively strong, which can improve the stability and reliability of the chip; on the other hand, the non-photosensitive region used to isolate the photosensitive region is part of the colloidal quantum dot photosensitive film, which will not affect the electrical properties of the photosensitive region, can limit the crosstalk between pixels, achieve lossless isolation between pixels of the focal plane chip, and further improve the optoelectronic performance and reliability of the infrared focal plane chip. Therefore, the colloidal quantum dot focal plane chip provided by the present invention can limit the crosstalk between pixels, achieve lossless isolation between pixels of the focal plane chip, and further improve the optoelectronic performance, reliability and stability of the infrared focal plane chip.

[0160] In some alternative embodiments, the first direction is perpendicular to the second direction; a plurality of pixel isolation layers 30 space a plurality of electrodes 20 into a plurality of electrode groups arranged at intervals along the first direction, and each electrode group includes a plurality of electrodes 20 arranged at intervals along the second direction;

[0161] The electrode groups and the pixel isolation layers 30 are alternately arranged;

[0162] In the second direction, the electrodes 20 and the pixel region 100 are alternately arranged;

[0163] The colloidal quantum dot photosensitive film 40 further includes an electrode region 43, and the electrode region 43 is located on the surface of the electrode 20 on the side facing away from the substrate 10;

[0164] In the second direction, the electrode region 43 and the photosensitive region 41 are alternately arranged.

[0165] In an alternative embodiment, the photosensitive region 41 has a crystal structure;

[0166] The non-photosensitive region 42 has an amorphous structure;

[0167] The carrier mobility of the non-photosensitive region 42 is less than that of the photosensitive region 41.

[0168] In an alternative embodiment, the carrier mobility of the photosensitive region 41 is greater than 0.6 cm 2 / (V·s);

[0169] The carrier mobility of the non-photosensitive region 42 is less than 0.001 cm 2 / (V·s).

[0170] In an alternative embodiment, the thickness of the electrode 20 is 20 nm to 100 nm;

[0171] The thickness of the pixel isolation layer 30 is 20 nm to 100 nm;

[0172] The thickness of the photosensitive region 41 is 150 nm to 500 nm;

[0173] The width of the pixel region 100 in the first direction is 5 μm to 200 μm;

[0174] The width of the electrode 20 in the first direction is 5 μm to 200 μm;

[0175] The ratio of the width of the electrode 20 in the second direction to the width of the pixel region 100 in the second direction is 1:8 to 1:4;

[0176] The width of the pixel isolation layer 30 in the first direction is 5 μm to 200 μm.

[0177] In an alternative embodiment, the material of the substrate 10 is silicon, silicon dioxide, or a silicon-based readout circuit;

[0178] The material of the metal oxide thin film is hafnium oxide, titanium oxide, or aluminum oxide;

[0179] The material of the electrode 20 is gold or titanium gold.

[0180] In some examples, the material of the substrate is a silicon-based readout circuit. When the colloidal quantum dot focal plane chip is operating, the electrodes on both sides of the pixel are connected to different potentials through the silicon-based readout circuit respectively.

[0181] In other examples, the material of the substrate is silicon or silicon dioxide. When the colloidal quantum dot focal plane chip is operating, the electrodes on both sides of the pixel and one side of the corresponding electrode region are led out through leads, and then connected to different potentials.

[0182] In the description of this specification, the description referring to terms such as "this embodiment", "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0183] In the above description, technical details such as the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of the required shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as the methods described above. In addition, although the above embodiments are described separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination.

[0184] The above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the above specific embodiments, and various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can also be included, and the protection scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for preparing a colloidal quantum dot focal plane chip, characterized in that: include: providing a substrate; A plurality of electrodes arranged in an array are formed on a surface of one side of the substrate; Forming a plurality of pixel isolation layers on a surface of one side of the substrate; The plurality of pixel isolation layers are arranged at intervals in the first direction and extend along the second direction; The plurality of electrodes and the plurality of pixel isolation layers together enclose a plurality of pixel regions arranged in an array, wherein the substrate surface is exposed in the pixel regions; A colloidal quantum dot photosensitive film is formed on one surface of the substrate, and the colloidal quantum dot photosensitive film covers the exposed surface of the substrate in the pixel area and encapsulates the pixel isolation layer and the electrode; the colloidal quantum dot photosensitive film includes a photosensitive area and a non-photosensitive area; the photosensitive area is located in the pixel area of ​​the substrate surface; the non-photosensitive area is located on the side surface of the pixel isolation layer facing away from the substrate.

2. The method for preparing a colloidal quantum dot focal plane chip according to claim 1, characterized in that: The first direction is perpendicular to the second direction; the plurality of pixel isolation layers separate the plurality of electrodes into a plurality of electrode groups spaced apart along the first direction, and the electrode groups include a plurality of electrodes spaced apart along the second direction; The electrode groups and the pixel isolation layers are arranged alternately; In the second direction, the electrodes and the pixel regions are arranged alternately.

3. The method for preparing a colloidal quantum dot focal plane chip according to claim 2, characterized in that: The colloidal quantum dot photosensitive film further comprises an electrode region, and the electrode region is located on the surface of the electrode facing away from the substrate; In the second direction, the electrode regions and the photosensitive regions are arranged alternately.

4. The method for preparing a colloidal quantum dot focal plane chip according to claim 1, characterized in that: The surface of the substrate is a hydrophilic surface; The pixel isolation layer is a metal oxide film, and the surface of the metal oxide film is a hydrophobic surface; The step of forming a colloidal quantum dot photosensitive film on the surface of the substrate, wherein the colloidal quantum dot photosensitive film covers the pixel area and encapsulates the pixel isolation layer and the electrode, comprises: Prepare a colloidal quantum dot material solution, wherein the colloidal quantum dot material solution comprises a colloidal quantum dot material and a solvent; the colloidal quantum dot material is suitable for forming a photosensitive area on a hydrophilic surface and a non-photosensitive area on a hydrophobic surface; Spin coating the colloidal quantum dot material solution on the exposed substrate surface of the pixel region, the pixel isolation layer surface and the electrode surface; Heating the colloidal quantum dot material solution in an inert gas atmosphere to form a colloidal quantum dot photosensitive film from the colloidal quantum dot material; The colloidal quantum dot material forms a non-photosensitive area on the surface of the pixel isolation layer facing away from the substrate in a non-crystalline manner, and the colloidal quantum dot material forms the photosensitive area in the pixel area on the substrate surface in a crystalline manner.

5. The method for preparing a colloidal quantum dot focal plane chip according to claim 4, characterized in that: The step of heating the colloidal quantum dot material solution in an inert gas atmosphere to form a colloidal quantum dot photosensitive film comprises: Heating the colloidal quantum dot material solution to a first temperature and for a first time in an inert gas atmosphere to completely remove the solvent, so that the colloidal quantum dot material forms a colloidal quantum dot photosensitive film; The first temperature is 80°C to 200°C; The first time is 10 minutes to 60 minutes.

6. The method for preparing a colloidal quantum dot focal plane chip according to claim 4, characterized in that: The colloidal quantum dot material includes quantum dots and perovskite ligands; In the colloidal quantum dot photosensitive film, the perovskite ligand surrounds the quantum dots; Wherein, the photosensitive region is a crystal structure, the quantum dots in the photosensitive region are arranged in an array, and the perovskite ligands uniformly surround the quantum dots; The non-photosensitive region is an amorphous structure, the quantum dots in the non-photosensitive region are irregularly arranged, and the perovskite ligands unevenly surround the quantum dots; The carrier mobility of the non-photosensitive region is smaller than the carrier mobility of the photosensitive region.

7. The method for preparing a colloidal quantum dot focal plane chip according to claim 6, characterized in that: The quantum dots are HgSe quantum dots; The perovskite ligand is a MAPbI3 perovskite ligand.

8. The method for preparing a colloidal quantum dot focal plane chip according to claim 6, characterized in that: The carrier mobility of the photosensitive region is greater than 0.6 cm 2 / (V·s); The carrier mobility of the non-photosensitive region is less than 0.001 cm 2 / (V·s).

9. The method for preparing a colloidal quantum dot focal plane chip according to claim 1, characterized in that: The thickness of the electrode is 20nm to 100nm; The thickness of the pixel isolation layer is 20nm to 100nm; The thickness of the photosensitive region is 150nm to 500nm; The width of the pixel area in the first direction is 5 μm to 200 μm; The width of the electrode in the first direction is 5 μm to 200 μm; The ratio of the width of the electrode in the second direction to the width of the pixel area in the second direction is 1:8 to 1:4; The width of the pixel isolation layer in the first direction is 5 μm to 200 μm.

10. The method for preparing a colloidal quantum dot focal plane chip according to claim 4, characterized in that: The material of the substrate is silicon, silicon dioxide or a silicon-based readout circuit; The material of the metal oxide film is hafnium oxide, titanium oxide or aluminum oxide; The material of the electrode is gold or titanium.

11. A colloidal quantum dot focal plane chip, characterized in that: include: substrate; A plurality of electrodes arranged in an array are located on one surface of the substrate; A plurality of pixel isolation layers are located on one surface of the substrate; The plurality of pixel isolation layers are arranged at intervals in the first direction and extend along the second direction; the plurality of electrodes and the plurality of pixel isolation layers together enclose a plurality of pixel regions arranged in an array; A colloidal quantum dot photosensitive film is located on one surface of the substrate, and the colloidal quantum dot photosensitive film also covers the pixel isolation layer and the electrode; the colloidal quantum dot photosensitive film includes a photosensitive area and a non-photosensitive area; the photosensitive area is located in the pixel area on the surface of the substrate; the non-photosensitive area is located on the side surface of the pixel isolation layer facing away from the substrate.

12. The colloidal quantum dot focal plane chip according to claim 11, characterized in that: The first direction is perpendicular to the second direction; the plurality of pixel isolation layers separate the plurality of electrodes into a plurality of electrode groups spaced apart along the first direction, and the electrode groups include a plurality of electrodes spaced apart along the second direction; The electrode groups and the pixel isolation layers are arranged alternately; In the second direction, the electrodes and the pixel regions are arranged alternately; The colloidal quantum dot photosensitive film further comprises an electrode region, and the electrode region is located on the surface of the electrode facing away from the substrate; In the second direction, the electrode areas and the photosensitive areas are arranged alternately; The carrier mobility of the non-photosensitive region is smaller than the carrier mobility of the photosensitive region.

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