Retina-simulating light detection device based on micro-jet printing molybdenum sulfide film and preparation method

Abstract

The present application relates to a kind of retinal light detection devices based on micro-jet printing molybdenum sulfide film and preparation method, belong to micro-nano manufacturing and optoelectronic device related technical field.Preparation method includes: (1) deposition release layer on the surface of rigid substrate, and flexible substrate is applied on the surface of release layer;(2) deposition insulation layer on the surface of flexible substrate, and metal electrode array is prepared on the insulation layer by photolithography method;(3) by micro-jet printing, atom-thick molybdenum sulfide composite film is sprayed between metal electrode channel;(4) flexible device array is cut, and it is spliced after being peeled from rigid substrate and the surface of spherical substrate, and spherical molybdenum sulfide light detection device is obtained.The present application uses the method of micro-jet printing to transfer molybdenum sulfide composite film to each pixel, with the obvious advantages of thin film coating uniformity, high quality of pixel, material saving, simple process, low cost and the like.

Description

Technical Field

[0001] This invention belongs to the technical field of micro-nano manufacturing and optoelectronic devices, and more specifically, relates to a retina-like photodetector device based on micro-sprayed molybdenum sulfide thin film and its preparation method. Background Technology

[0002] As a major branch of sensing technology, photoelectric detection and imaging technology is widely used in military equipment, aerospace remote sensing, industrial production, medical diagnosis, and other fields, demonstrating enormous application value in national defense and people's livelihood. The spherical retina-like imaging device prepared in this invention has great application prospects in artificial vision, flexible bioelectronic devices, and other fields.

[0003] In recent years, transition metal sulfides, represented by molybdenum disulfide (MoD), have attracted widespread attention in two-dimensional materials due to their excellent optical and electrical properties. Photodetectors based on MoD thin films exhibit high photodetectivity, high photoresponsivity, and fast response speed, showing broad application prospects in next-generation photodetectors. Currently, commonly used methods for preparing MoD thin films include mechanical exfoliation, CVD growth, liquid-phase exfoliation, and electrochemical exfoliation. Mechanical exfoliation has low yield and is only suitable for research applications; CVD growth involves complex preparation and transfer processes, and wafer-level fabrication remains difficult. Moreover, for imaging arrays, the film outside the pixels is redundant, resulting in low utilization efficiency. Liquid-phase exfoliation and electrochemical exfoliation methods produce relatively low-cost and high-yield MoD dispersions, but they are often deposited between electrodes using spin-coating. Due to differences in centrifugal force during spin-coating and the redispersion of fragments in the solution, uneven film coating is inevitable, leading to large differences in photoresponse between pixels. This is detrimental to subsequent signal processing and results in poor image quality. In addition, traditional planar photodetectors have pixels distributed on a rigid plane, which can lead to problems such as small field of view and image distortion in some applications.

[0004] The invention patent with publication number CN 111916524 A discloses the preparation of large-area molybdenum sulfide thin films using CVD growth method. However, this method has the disadvantages of complex preparation and transfer, and most of the film will be etched away in the end. The process is complicated and the material utilization rate is low. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a retinal-mimicking photodetector device and its fabrication method based on micro-spraying of molybdenum sulfide thin films. The device utilizes a micro-spraying process to transfer a molybdenum sulfide composite thin film. This process allows for precise spraying of target ink within the micrometer range. By ensuring that an equal amount of uniform ink is sprayed each time, the film at each pixel can be relatively uniform, thus guaranteeing a consistent light response across all pixels. Furthermore, the pixels of the device are distributed on a spatial sphere, uniformly distributed along the latitudinal direction and varying in density along the longitudinal direction, effectively simulating the characteristics of the human retina and enabling large field-of-view and spatially variable resolution imaging. This solves the technical problem of uneven film coating in existing technologies, which leads to large differences in light response between pixels, hindering subsequent signal processing and resulting in poor image quality.

[0006] According to a first aspect of the present invention, a method for fabricating a retinal-like photodetector based on micro-printed molybdenum sulfide thin film is provided, comprising the following steps:

[0007] (1) Deposit a release layer on the surface of a rigid substrate, and coat a flexible substrate on the surface of the release layer;

[0008] (2) An insulating layer is deposited on the surface of a flexible substrate, and a metal interconnect layer and a metal electrode array are successively fabricated on the insulating layer by photolithography.

[0009] (3) Molybdenum sulfide ink was sprayed between the channels formed by the metal electrode array by micro-spraying to obtain a molybdenum sulfide film with atomic-level thickness.

[0010] (4) The flexible substrate is cut and peeled off from the rigid substrate and spliced ​​with the surface of the spherical substrate to obtain a spherical retina-like photodetector device.

[0011] Preferably, in step (3), the micro-printing is continuous deflection inkjet printing, piezoelectric inkjet printing, heated inkjet printing or electrothermal inkjet printing.

[0012] Preferably, the molybdenum sulfide film is a composite film of molybdenum sulfide and tungsten sulfide, a composite film of molybdenum sulfide and tungsten selenide, a composite film of molybdenum sulfide and black phosphorus, or a composite film of molybdenum sulfide and rhenium selenide.

[0013] Preferably, the molybdenum sulfide ink is prepared by liquid phase exfoliation or electrochemical exfoliation, and the size of the molybdenum sulfide fragments in the ink is 100nm-5μm, the concentration is 1mg / mL-50mg / mL, the viscosity is 1cps-10000cps, and the surface tension is 5mN / m-50mN / m; the thickness of the molybdenum sulfide film is 0.7nm-20nm.

[0014] Preferably, the rigid substrate is a silicon wafer, a quartz wafer, or a sapphire wafer; the release layer is Ni, Cu, Al, or SiO2 with a thickness of 50nm-100nm; and the flexible substrate material is PMMA, PI, or SEBS with a thickness of 2μm-50μm.

[0015] Preferably, the material of the metal electrode array is Ti, Ni, Cr, Au or Ag, and the thickness is 50nm-200nm; the channel spacing formed by the metal electrode array is 3μm-15μm.

[0016] Preferably, the deposition in steps (1) and (2) is achieved by a coating process;

[0017] Preferably, the coating process is magnetron sputtering, electron beam evaporation, thermal evaporation, or atomic layer deposition.

[0018] Preferably, the cutting in step (4) is specifically implemented by using laser cutting to cut the flexible substrate so that it is consistent with the two-dimensional decomposition pattern of the spherical molybdenum sulfide photodetector; the peeling is specifically implemented by etching the rigid substrate or etching the peeling layer; the method of transferring the flexible substrate to the spherical substrate is PMMA-assisted wet transfer or PDMS-assisted dry transfer.

[0019] According to another aspect of the present invention, a retina-like photodetector device prepared by any of the methods described herein is provided.

[0020] Preferably, the unit imaging unit on the device is composed of a molybdenum sulfide thin film and a pair of metal electrodes connected to its two ends; the pixels on the device are distributed on a spatial sphere, and the pixels are evenly distributed along the latitudinal direction, while the pixel density gradually decreases from the top to the bottom along the longitudinal direction.

[0021] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0022] (1) The present invention provides uniform film coating and high pixel quality. Spin coating inevitably leads to uneven film coating due to differences in centrifugal force and redistribution of the film in the solution, resulting in large differences in light response between pixels, which is not conducive to subsequent signal processing. In contrast, the micro-inkjet printing method only needs to spray an equal amount of uniform ink each time to ensure uniform film quality at each pixel.

[0023] (2) The device of the present invention has a large field of view. Traditional planar photodetectors have pixels distributed on a single plane, resulting in a small field of view and distortion. The device structure of the present invention adopts a retina-like design, with each pixel distributed on a spatial sphere, uniformly distributed along the latitudinal direction and varying density along the longitudinal direction, effectively simulating the characteristics of the human retina, and enabling functions such as large field of view and spatial variable resolution imaging.

[0024] (3) This invention saves materials. Both CVD growth and spin coating methods require etching away the molybdenum sulfide film outside the array, resulting in a large amount of waste of molybdenum sulfide film. However, the micro-spraying method can directly spray molybdenum sulfide to form an array with almost no waste.

[0025] (4) The process of this invention is simple. Currently, it is still relatively difficult to prepare large-size molybdenum sulfide thin films using CVD growth, and they need to be transferred to planar devices after preparation. In contrast, micro-inkjet printing, which uses chemical or electrochemical stripping methods to prepare molybdenum sulfide ink, is much simpler. Furthermore, to obtain molybdenum sulfide array patterns, both CVD growth and spin coating methods require etching of excess molybdenum sulfide film. This process involves a series of operations such as mask fabrication, photolithography, and etching, making the process complex. Micro-inkjet printing, however, allows for direct point-to-point spraying of molybdenum sulfide, requiring only one step to obtain the molybdenum sulfide array.

[0026] (5) The present invention has low cost. The micro-printing method has a high utilization rate of molybdenum sulfide, so its material cost is low; in addition, the micro-printing method does not require the fabrication of additional masks and related etching processes, which also reduces the device fabrication cost. Attached Figure Description

[0027] Figure 1 Schematic diagram of inkjet printing of MoS2 thin film;

[0028] Figure 2 This is a schematic diagram of the device after the flexible substrate has been cut.

[0029] Figure 3 for Figure 2 A magnified schematic diagram of the unit imaging cell structure in the device shown;

[0030] Figure 4 for Figure 2 A partial cross-sectional view of a unit imaging cell on the device shown.

[0031] Figure 5 This is a flowchart of the preparation method of the present invention.

[0032] In all the figures, the same reference numerals are used to denote the same elements or structures: 10-rigid substrate, 11-release layer, 12-flexible substrate, 13-metal bonding layer, 14-metal electrode array, 15-molybdenum sulfide thin film. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0034] The present invention relates to a method for fabricating a retinal-like photodetector device based on micro-spray printing of molybdenum sulfide thin films, characterized by comprising the following steps:

[0035] (1) Deposit a release layer on the surface of a rigid substrate, and coat a flexible substrate on the surface of the release layer;

[0036] (2) An insulating layer is deposited on the surface of a flexible substrate, and a metal interconnect layer and a metal electrode array are successively fabricated on the insulating layer through photolithography, film deposition, etching and other processes.

[0037] (3) Atom-thick molybdenum sulfide composite film is sprayed onto the channels formed by the metal electrode array by micro-spraying.

[0038] (4) The flexible substrate is cut and peeled off from the rigid substrate and spliced ​​with the surface of the spherical substrate to obtain a spherical retina-like photodetector device.

[0039] In some embodiments, the rigid substrate used in step (1) is a silicon wafer, a quartz wafer, a sapphire wafer, etc.; the deposited release layer is Ni, Cu, Al, SiO2, etc., with a thickness between 50 and 100 nm; the flexible substrate material is PMMA, PI, SEBS, etc., with a thickness between 2 and 50 μm.

[0040] In some embodiments, the metal electrode material in step (2) can be Ti, Ni, Cr, Au, Ag, etc., with a thickness between 50nm and 200nm. If the thickness is too small, it will be unfavorable for testing and lead packaging in subsequent steps. If the thickness is too large, it will cause the photoresist to degenerate due to high temperature during deposition, affecting the subsequent photoresist removal operation.

[0041] In some embodiments, the deposition in steps (1) and (2) is achieved by a coating process, which may be magnetron sputtering, electron beam evaporation, thermal evaporation, atomic layer deposition, etc.

[0042] In some embodiments, the micro-printing mentioned in step (3) refers to various printing processes, such as continuous deflection inkjet printing, piezoelectric inkjet printing, heated inkjet printing, electrofluid printing, etc. This micro-printing process can precisely spray molybdenum sulfide composite films between the metal electrode channels at each pixel; the MoS2 composite film is composed of MoS2 film and related two-dimensional material films, and other film components can be WS2, WSe, BP, ReSe2, etc.

[0043] In some embodiments, step (3) requires the preparation of a molybdenum sulfide composite film ink for printing before micro-printing. This ink can be prepared by chemical stripping or electrochemical stripping. The size of the molybdenum sulfide composite film in the ink is between 100 nm and 5 μm, the thickness of the prepared film is between 0.7 nm and 20 nm, the ink concentration is between 1 and 50 mg / mL, the viscosity is between 1 and 10000 cPs, and the surface tension is between 5 and 50 mN / m.

[0044] In some embodiments, the cutting in step (4) is specifically implemented by using laser cutting to cut the flexible substrate so that it is consistent with the two-dimensional decomposed pattern of the spherical molybdenum sulfide photodetector; the peeling is specifically implemented by etching the rigid substrate or etching the peeling layer; the transfer process of the flexible substrate can be PMMA-assisted wet transfer or PDMS-assisted dry transfer process, etc.

[0045] The retinal-like photodetector structure prepared by the present invention includes: (1) a spherical substrate supporting the device; (2) a flexible substrate 12 for transfer; (3) a metal electrode array 14 distributed on the flexible substrate; and (4) a sulfide film 15 connecting the metal electrode channels. A release layer 11 is also present between the rigid substrate 10 and the flexible substrate 12, and a metal connection layer 13 is also present between the flexible substrate 12 and the metal electrode array 14.

[0046] The retinal-like photodetector device prepared by this invention has pixels distributed on a spatial sphere, uniformly distributed along the latitudinal direction and with varying density along the longitudinal direction (density gradually decreases from top to bottom). For example... Figure 1 As shown, the present invention uses a micro-spraying method to transfer the MoS2 composite film, which can effectively avoid the uneven film coating of the traditional spin coating method. This makes the quality of the MoS2 composite film at each pixel on the device prepared by the present invention basically consistent, which is beneficial to the subsequent signal processing and imaging quality improvement.

[0047] like Figure 2 As shown, in the two-dimensional decomposition pattern of the molybdenum sulfide photodetector proposed in this invention, each imaging unit is uniformly distributed along the circumference and has a variable density distribution along the radius. This allows the pixels on the spliced ​​spherical device to be uniformly distributed along the latitudinal direction and have a variable density distribution along the longitudinal direction, effectively simulating the structural features of the human retina. It can simultaneously meet the functions of omnidirectional detection, large field of view imaging, and spatial variable resolution imaging.

[0048] like Figure 3 As shown, any imaging unit on the molybdenum sulfide photodetector disclosed in this invention is composed of a molybdenum sulfide thin film and a pair of metal electrodes connected at both ends thereto, wherein the channel spacing between the metal electrodes is between 3 μm and 15 μm.

[0049] like Figure 4As shown, the method for fabricating the molybdenum sulfide photodetector disclosed in this invention includes:

[0050] (a) Depositing a release layer on a rigid substrate surface and coating a flexible substrate on the release layer surface;

[0051] (b) An insulating layer is deposited on the surface of a flexible substrate, and a metal electrode array is fabricated on the insulating layer by combining photolithography, thin film deposition and wet stripping processes;

[0052] (c) Atomic-thick molybdenum sulfide composite films are printed between metal electrode channels by micro-spraying to achieve electrical connection between electrode-molybdenum sulfide-electrode.

[0053] (d) The flexible device array is cut and peeled off from the rigid substrate and spliced ​​with the surface of the spherical substrate to obtain a spherical molybdenum sulfide photodetector.

[0054] The following are specific embodiments.

[0055] Example 1

[0056] This invention relates to a method for fabricating a retinal-like photodetector device based on micro-spray printing of molybdenum sulfide thin films. The fabrication flowchart is shown below. Figure 5 As shown.

[0057] (1) Prepare PDMS solution, pour it into a spherical substrate mold, wait for it to solidify, and demold to obtain a spherical substrate;

[0058] (2) Select a circular silicon wafer with a diameter of 2 inches as a planar rigid substrate, clean the silicon wafer, and deposit a Ni stripping layer with a thickness of 150nm on its surface using an electron beam evaporation coating process.

[0059] (3) A layer of PI flexible substrate with a thickness of 5 μm was spin-coated onto the surface of the Ni release layer using a spin coater at a spin speed of 1800 r / s and an acceleration of 300 r / s. 2 ;

[0060] (4) An Al2O3 thin film with a thickness of 5 nm was deposited on the PI flexible substrate using atomic layer deposition process to avoid the influence of subsequent device fabrication processes on the flexible substrate.

[0061] (5) A layer of negative photoresist is uniformly coated on the Al2O3 film deposited in step (4). After photolithography and development, the photoresist at the metal electrode array pattern position is dissolved and removed.

[0062] (6) An electron beam evaporation coating process is used to deposit a Cr film with a thickness of 10 nm on the device treated in step (5) to facilitate the subsequent deposition of metal electrodes on the device.

[0063] (7) A layer of Au with a thickness of 40 nm was deposited on the Cr film using a resistance thermal evaporation coating process;

[0064] (8) The device is immersed in acetone solvent to remove the adhesive. After the adhesive is removed, the metal electrode array remains on the flexible substrate.

[0065] (9) Employing micro-inkjet printing technology, such as Figure 1 As shown, a MoS2 composite film is sprayed onto the metal electrode channel to form an electrical connection between the electrode and molybdenum sulfide. Figure 3 As shown;

[0066] (10) Laser etching technology is used to remove excess flexible substrate and insulating layer, ensuring that the etched pattern matches the two-dimensional decomposed pattern of the spherical device, such as... Figure 2 As shown;

[0067] (11) The Ni stripping layer on the rigid substrate is etched by wet etching process to achieve the stripping of the flexible device array;

[0068] (12) The stripped flexible device array is transferred to a pre-prepared spherical substrate using PDMS-assisted dry transfer technology to obtain a spherical retina-like imaging device.

[0069] (13) The prepared imaging device is wire bonded and packaged.

[0070] Example 2

[0071] This invention relates to a method for fabricating a retinal-like photodetector device based on micro-spray printing of molybdenum sulfide thin films. The fabrication flowchart is shown below. Figure 5 As shown.

[0072] (1) Prepare PDMS solution, pour it into a spherical substrate mold, wait for it to solidify, and demold to obtain a spherical substrate;

[0073] (2) Select a quartz sheet of appropriate size as a planar rigid substrate, clean the quartz sheet, and deposit a Cu stripping layer with a thickness of 100nm on its surface using electron beam evaporation coating process.

[0074] (3) A PI flexible substrate with a thickness of 10 μm was spin-coated onto the surface of the Cu release layer using a spin coater at a spin speed of 1500 r / s and an acceleration of 300 r / s. 2 ;

[0075] (4) An atomic layer deposition process is used to deposit a Si3N4 thin film with a thickness of 5nm on the PI flexible substrate to avoid the influence of subsequent device fabrication processes on the flexible substrate.

[0076] (5) A layer of negative photoresist is uniformly coated on the Si3N4 film deposited in step (4). After photolithography and development, the photoresist at the metal electrode array pattern position is dissolved and removed.

[0077] (6) An electron beam evaporation coating process is used to deposit a Cr film with a thickness of 10 nm on the device treated in step (5) to facilitate the subsequent deposition of metal electrodes on the device.

[0078] (7) A layer of Au with a thickness of 40 nm was deposited on the Cr film using a resistance thermal evaporation coating process;

[0079] (8) The device is immersed in acetone solvent to remove the adhesive. After the adhesive is removed, the metal electrode array remains on the flexible substrate.

[0080] (9) Employing micro-inkjet printing technology, such as Figure 1 As shown, a MoS2 composite film is sprayed onto the metal electrode channel to form an electrical connection between the electrode and molybdenum sulfide. Figure 3 As shown;

[0081] (10) Laser etching technology is used to remove excess flexible substrate and insulating layer, ensuring that the etched pattern matches the two-dimensional decomposed pattern of the spherical device, such as... Figure 2 As shown;

[0082] (11) The Cu stripping layer on the rigid substrate is etched by wet etching process to achieve the stripping of the flexible device array;

[0083] (12) The stripped flexible device array is transferred to a pre-prepared spherical substrate using PDMS-assisted dry transfer technology to obtain a spherical retina-like imaging device.

[0084] (13) The prepared imaging device is wire bonded and packaged.

[0085] Example 3

[0086] This invention relates to a method for fabricating a retinal-like photodetector device based on micro-spray printing of molybdenum sulfide thin films. The fabrication flowchart is shown below. Figure 5 As shown.

[0087] (1) Prepare PDMS solution, pour it into a spherical substrate mold, wait for it to solidify, and demold to obtain a spherical substrate;

[0088] (2) Select a sapphire sheet of appropriate size as a planar rigid substrate, clean the sapphire sheet, and deposit an Al release layer with a thickness of 200nm on its surface using electron beam evaporation coating process.

[0089] (3) A layer of PI flexible substrate with a thickness of 20 μm was spin-coated onto the surface of the Al release layer using a spin coater at a spin speed of 1000 r / s and an acceleration of 300 r / s. 2 ;

[0090] (4) An atomic layer deposition process is used to deposit a SiO2 thin film with a thickness of 5 nm on the PI flexible substrate to avoid the influence of subsequent device fabrication processes on the flexible substrate.

[0091] (5) A layer of negative photoresist is uniformly coated on the SiO2 film deposited in step (4). After photolithography and development, the photoresist at the metal electrode array pattern position is dissolved and removed.

[0092] (6) An electron beam evaporation coating process is used to deposit a Cr film with a thickness of 10 nm on the device treated in step (5) to facilitate the subsequent deposition of metal electrodes on the device.

[0093] (7) A layer of Au with a thickness of 40 nm was deposited on the Cr film using a resistance thermal evaporation coating process;

[0094] (8) The device is immersed in acetone solvent to remove the adhesive. After the adhesive is removed, the metal electrode array remains on the flexible substrate.

[0095] (9) Employing micro-inkjet printing technology, such as Figure 1 As shown, a MoS2 composite film is sprayed onto the metal electrode channel to form an electrical connection between the electrode and molybdenum sulfide. Figure 3 As shown;

[0096] (10) Laser etching technology is used to remove excess flexible substrate and insulating layer, ensuring that the etched pattern matches the two-dimensional decomposed pattern of the spherical device, such as... Figure 2 As shown;

[0097] (11) The Al release layer on the rigid substrate is etched by wet etching process to achieve the release of flexible device array;

[0098] (12) The stripped flexible device array is transferred to a pre-prepared spherical substrate using PDMS-assisted dry transfer technology to obtain a spherical retina-like imaging device.

[0099] (13) The prepared imaging device is wire bonded and packaged.

[0100] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a retinal-like photodetector device based on micro-jet printing of molybdenum disulfide thin film, characterized in that, The method comprises the following steps: (1) depositing a release layer on the surface of a rigid substrate, and coating a flexible substrate on the surface of the release layer; (2) depositing an insulating layer on the surface of the flexible substrate, and successively preparing a metal connecting layer and a metal electrode array on the insulating layer by photolithography; (3) spraying a molybdenum sulfide ink between the channels formed by the metal electrode array by a micro-jet printing method to obtain a molybdenum sulfide film with an atomic thickness; the channel spacing of the channels formed by the metal electrode array is 3 µm-15 µm; (4) cutting the flexible substrate and peeling it off from the rigid substrate to splice it with the surface of a spherical substrate to obtain a spherical retinal light detection imaging device; a unit imaging unit on the device is composed of the molybdenum sulfide film and a pair of metal electrodes connected at both ends of the molybdenum sulfide film, and the imaging units in the same meridional direction share an anode or a cathode.

2. The method for preparing a micro-jet-printed molybdenum sulfide thin film-based retinal-like photodetector imaging device according to claim 1, wherein the molybdenum sulfide thin film is formed by a chemical vapor deposition method. In step (3), the micro-jet printing is continuous deflection inkjet printing, piezoelectric inkjet printing, heating inkjet printing or electrofluidic inkjet printing.

3. The method for preparing a micro-jet-printed molybdenum sulfide thin film-based retinal-like photodetector imaging device according to claim 1 or 2, wherein The molybdenum sulfide film is a molybdenum sulfide and tungsten sulfide composite film, a molybdenum sulfide and tungsten selenide composite film, a molybdenum sulfide and black phosphorus composite film, or a molybdenum sulfide and rhenium selenide composite film.

4. The method for preparing a micro-jet-printed molybdenum sulfide thin film-based retinal-like photodetector imaging device according to claim 1, wherein the molybdenum sulfide thin film is formed by a chemical vapor deposition method. The molybdenum sulfide ink is prepared by a liquid phase exfoliation method or an electrochemical exfoliation method, the size of molybdenum sulfide fragments in the ink is 100 nm-5 µm, the concentration is 1 mg / mL-50 mg / mL, the viscosity is 1 cps-10000 cps, and the surface tension is 5 mN / m-50 mN / m; the thickness of the molybdenum sulfide film is 0.7 nm~20 nm.

5. The method for preparing a micro-jet-printed molybdenum sulfide thin film-based retinal-like photodetector imaging device according to claim 1, wherein the molybdenum sulfide thin film is formed by a chemical vapor deposition method. The rigid substrate is a silicon wafer, a quartz wafer or a sapphire wafer; the release layer is Ni, Cu, Al or SiO2, and the thickness is 50 nm-100 nm; the flexible substrate material is PMMA, PI or SEBS, and the thickness is 2 µm-50 µm.

6. The method for preparing a micro-jet-printed molybdenum sulfide thin film-based retinal-like photodetector imaging device according to claim 1, wherein the molybdenum sulfide thin film is formed by a chemical vapor deposition method. The material of the metal electrode array is Ti, Ni, Cr, Au or Ag, and the thickness is 50 nm-200 nm.

7. The method for preparing a micro-jet-printed molybdenum sulfide thin film-based retinal-like photodetector imaging device according to claim 1, wherein the molybdenum sulfide thin film is formed by a chemical vapor deposition method. The deposition in steps (1) and (2) is realized by a coating process.

8. The method for preparing a micro-jet-printed molybdenum sulfide thin film-based retinal-like photodetector imaging device according to claim 7, wherein the molybdenum sulfide thin film is formed by a chemical vapor deposition method. The coating process is magnetron sputtering, electron beam evaporation, thermal evaporation or atomic layer deposition.

9. The method for preparing a micro-jet-printed molybdenum disulfide thin film-based retinal-like photodetector imaging device according to claim 1, wherein, In step (4), the cutting is realized by cutting the flexible substrate with a laser to make it consistent with the two-dimensional decomposition pattern of the spherical molybdenum sulfide light detection imaging device; the peeling is realized by etching the rigid substrate or etching the release layer; the method of transferring the flexible substrate to the spherical substrate is PMMA-assisted wet transfer or PDMS-assisted dry transfer.

10. A retinal light detection imaging device prepared by the method of any one of claims 1-9.

11. The retinal-simulating photodetecting imaging device of claim 10, wherein, The image elements on the device are distributed on a spherical surface, and the image elements are uniformly distributed along the latitudinal direction, and the density of the image elements gradually decreases from the top to the bottom along the longitudinal direction.

Images