A double floating gate photodiode with nearly ideal linear response and its preparation method

Abstract

The present invention discloses a dual floating-gate photodiode with a near-ideal linear response and a method for preparing the same, belonging to the technical field of photodetector preparation. The present invention discloses a dual floating-gate photodiode with a near-ideal linear response, comprising, from bottom to top, a SiO2 / Si substrate, a dielectric layer, a first MoTe2 layer as a bottom floating gate, a first MoS2 layer as an N-terminal, a second MoTe2 layer as a P-terminal, a second MoS2 layer as a top floating gate, and a pair of electrodes arranged on the surface. The disclosed structure further forms two type II van der Waals heterostructures (MoS2 / MoTe2 and MoTe2 / MoS2) on the upper and lower sides of the MoS2 / MoTe2 heterojunction. Under the action of the built-in electric field of the type II heterojunctions on both sides, the minority carriers in the conductive channel of the heterojunction are more completely depleted, the interaction between the majority carriers and the minority carriers in the channel is weakened, and a near-ideal linear response is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of photoelectric detector preparation, and in particular relates to a double-floating-gate photodiode with nearly ideal linear response and a preparation method thereof. Background Art

[0002] Photodetectors, devices that convert light into electrical signals, are the cornerstone of modern optical communications, environmental monitoring, artificial intelligence, and other applications. With the advancement of process technology and increasing commercial demand, high-performance photodetectors are increasingly demanding in terms of sensitivity, speed, linear response, operating bandwidth, and integration. Photoactive materials and their structures are crucial components of photodetectors. Two-dimensional materials are widely used in photodiodes and phototransistors due to their high carrier mobility, tunable band gap, flexibility, and large light absorption cross-section.

[0003] Linear response to light intensity is an important indicator for photodetectors to accurately identify light signals. Generally, due to the inevitable carrier confinement in the atomically thin channel, it is difficult for two-dimensional material phototransistors to achieve a linear response. However, it is much easier for two-dimensional material photodiodes with a built-in electric field to promote the separation of photogenerated carriers. Ideal photodiodes show a strong linear photoelectric response due to the lack of carrier interaction. However, the doping level or carrier regulation conditions in the two-dimensional material photodiodes actually prepared have certain non-uniformities. For example, the carrier distribution near the top and bottom interfaces of the photodiode channel is different, the electron / hole depletion of the P / N end material is not complete, and the single material channel still exists in the non-junction region of the planar structure device, etc., which may lead to obvious nonlinear response. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a dual floating gate photodiode with near-ideal linear response and a preparation method thereof, so as to solve the technical problems of the existing photodiodes such as nonlinear light response and low photodetection efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention discloses a dual floating gate photodiode with a nearly ideal linear response, comprising a SiO2 / Si substrate, wherein a dielectric layer is provided on the upper surface of the SiO2 / Si substrate; a first MoTe2 layer as a bottom floating gate is provided on the upper surface of the dielectric layer; a first MoS2 layer as an N-terminal is provided on the upper surface of the first MoTe2 layer; a second MoTe2 layer as a P-terminal is provided on the upper surface of the first MoS2 layer; and a second MoS2 layer as a top floating gate is provided on the upper surface of the second MoTe2 layer.

[0007] One end of the first MoS2 layer contacts the surface of the dielectric layer, and the other end is arranged on the upper surface of the first MoTe2 layer; one end of the second MoTe2 layer contacts the surface of the dielectric layer, and the other end contacts the upper surface of the first MoS2 layer;

[0008] Electrodes are respectively provided on the upper surfaces of the first MoS2 layer and the second MoTe2 layer that are in contact with the surface of the dielectric layer.

[0009] Furthermore, the material of the dielectric layer is boron nitride (hBN).

[0010] Furthermore, the thickness of the dielectric layer is 14-20 nm.

[0011] Furthermore, the material of the electrode is gold, silver or palladium.

[0012] Furthermore, the thickness of the electrode is 45-50 nm.

[0013] Furthermore, the SiO2 / Si substrate comprises a SiO2 substrate and a Si substrate, and the SiO2 substrate is arranged on the upper surface of the Si substrate; the thickness of the SiO2 substrate is 280 to 300 nm.

[0014] The present invention also discloses a method for preparing the above-mentioned dual floating gate photodiode with near-ideal linear response, comprising the following steps:

[0015] S1: The dielectric layer is transferred to the upper surface of the SiO2 / Si substrate by a dry transfer technology; the first MoTe2 layer is transferred to the upper surface of the dielectric layer by a fixed-point transfer method as a bottom floating gate; then the first MoS2 layer is transferred to the upper surface of the first MoTe2 layer as the N terminal, wherein one end of the first MoS2 layer contacts the upper surface of the dielectric layer, and the other end contacts the upper surface of the first MoTe2 layer; then the second MoTe2 layer is transferred to the upper surface of the first MoS2 layer as the P terminal, wherein one end of the second MoTe2 layer contacts the upper surface of the dielectric layer, and the other end contacts the upper surface of the first MoS2 layer; the second MoS2 layer is transferred to the upper surface of the second MoTe2 layer as a top floating gate; finally, the electrodes are respectively transferred to the upper surfaces of the first MoS2 layer and the second MoTe2 layer in contact with the upper surface of the dielectric layer to obtain a pre-processed part;

[0016] S2: Annealing the pre-treated component to obtain a dual floating gate photodiode with a nearly ideal linear response.

[0017] Furthermore, the material of the dielectric layer is hBN; the material of the electrode is Au;

[0018] S1: hBN crystal material, MoTe2 crystal material and MoS2 crystal material are respectively peeled off onto the PDMS substrate by mechanical exfoliation method to form hBN nanosheets, MoTe2 nanosheets and MoS2 nanosheets;

[0019] Then, the hBN nanosheets on the PDMS substrate were transferred to the upper surface of the SiO2 / Si substrate using a dry transfer technique to form a dielectric layer;

[0020] Then, the hBN nanosheets on the upper surface of the SiO2 / Si substrate and the MoTe2 nanosheets on the PDMS substrate were found by the micro-focusing system, and the PDMS substrate with the MoTe2 nanosheets was transferred to the top of the hBN nanosheets. The PDMS substrate with the MoTe2 nanosheets was then lowered until it was completely attached to the upper surface of the hBN nanosheets, thus obtaining the first MoTe2 layer.

[0021] The MoS2 nanosheets on the first MoTe2 layer and the PDMS substrate are found separately by the micro-focusing system, and the PDMS substrate with the MoS2 nanosheets is transferred to the top of the first MoTe2 layer. The PDMS substrate with the MoS2 nanosheets is then lowered until it is completely attached to the upper surface of the first MoTe2 layer, thereby obtaining the first MoS2 layer.

[0022] The MoTe2 nanosheets on the first MoS2 layer and the PDMS substrate were found by the micro-focusing system, and the PDMS substrate with the MoTe2 nanosheets was transferred to the top of the first MoS2 layer. The PDMS substrate with the MoTe2 nanosheets was then lowered until it was completely attached to the upper surface of the first MoS2 layer to obtain the second MoTe2 layer.

[0023] The MoS2 nanosheets on the second MoTe2 layer and the PDMS substrate were found separately by the micro-focusing system, and the PDMS substrate with the MoS2 nanosheets was transferred to the top of the second MoTe2 layer. The PDMS substrate with the MoS2 nanosheets was then lowered until it was completely attached to the upper surface of the second MoTe2 layer to obtain the second MoS2 layer.

[0024] transferring electrodes to upper surfaces of the first MoS2 layer and the second MoTe2 layer in contact with the upper surface of the dielectric layer, respectively, to obtain a pre-processed part;

[0025] S2: Annealing the pre-treated component to obtain a dual floating gate photodiode with a nearly ideal linear response.

[0026] Furthermore, the annealing treatment is performed in a mixed gas of argon and hydrogen, the temperature of the annealing treatment is 200-230° C., and the time of the annealing treatment is 30-40 minutes.

[0027] Furthermore, the volume ratio of argon to hydrogen in the mixed gas of argon and hydrogen is 9:1.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention discloses a dual-floating-gate photodiode with a near-ideal linear response. The structure comprises, from bottom to top, a SiO2 / Si substrate, a dielectric layer, a first MoTe2 layer serving as a bottom floating gate, a first MoS2 layer serving as an N-terminal, a second MoTe2 layer serving as a P-terminal, a second MoS2 layer serving as a top floating gate, and a pair of electrodes disposed on the surface. The disclosed structure further forms two type II van der Waals heterostructures (MoS2 / MoTe2 and MoTe2 / MoS2) on the upper and lower sides of the MoS2 / MoTe2 heterojunction. Under the action of the built-in electric field of the type II heterojunctions on both sides, the minority carriers in the conductive channel of the heterojunction are more completely depleted, weakening the interaction between majority and minority carriers in the channel, thereby achieving a near-ideal linear response. The addition of the top floating-gate MoS2 layer further thoroughly depletes holes at the P-terminal, resulting in improved linearity of the photocurrent. This solves technical problems such as the nonlinear photoresponse and low photodetection efficiency of existing photodiodes.

[0030] The present invention also discloses a method for preparing the above-mentioned dual floating gate photodiode with near-ideal linear response. The preparation process uses mechanical stripping and dry transfer technology to construct a photodiode with strong linear response in a simple and convenient way. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the structure of the double floating gate photodiode with nearly ideal linear response of the present invention;

[0032] Figure 2 An optical microscope image of a dual floating gate photodiode with a near-ideal linear response according to the present invention;

[0033] Figure 3 This is a graph showing how the short-circuit current and open-circuit voltage of the dual-floating-gate photodiode with near-ideal linear response of the present invention change with incident light power under 532nm laser illumination;

[0034] Figure 4 This is a graph showing the variation of photocurrent with incident light power under incident light of different wavelengths for the dual floating gate photodiode with near-ideal linear response of the present invention;

[0035] Figure 5 This is a graph showing the variation of photocurrent with incident light power under 635nm laser illumination and a gate voltage range of -60 to 60V for a near-ideal linear response dual-floating-gate photodiode of the present invention;

[0036] Figure 6 A diagram showing the multi-wavelength imaging capability of the dual floating gate photodiode with near-ideal linear response according to the present invention;

[0037] Figure 7 Schematic diagram of the structure of the single floating gate MoTe2 / MoS2 van der Waals heterojunction photodiode in Comparative Example 1;

[0038] Figure 8 Graph showing the variation of photocurrent with incident light power of the single floating gate MoTe2 / MoS2 van der Waals heterojunction photodiode in Comparative Example 1 under 532nm laser illumination;

[0039] Wherein: 1-SiO2 / Si substrate; 2-dielectric layer; 3-first MoTe2 layer; 4-first MoS2 layer; 5-second MoTe2 layer; 6-second MoS2 layer; 7-electrode. DETAILED DESCRIPTION

[0040] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0041] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0042] Herein, all features such as values, amounts, amounts, and concentrations defined in numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0043] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0044] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0045] The present invention provides a double floating gate photodiode with nearly ideal linear response, the structure of which is as follows: Figure 1 As shown, from bottom to top are SiO2 / Si substrate 1, dielectric layer 2, first MoTe2 layer 3 as bottom floating gate, first MoS2 layer 4 as N-terminal, second MoTe2 layer 5 as P-terminal, second MoS2 layer 6 as top floating gate and a pair of electrodes 7; the specific optical microscope image is shown in FIG. Figure 2 shown.

[0046] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0047] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0048] Example 1

[0049] A method for preparing a dual floating gate photodiode with a nearly ideal linear response comprises the following steps:

[0050] S1: Cut a commercial SiO2 / Si wafer into 1 cm square pieces, clean and blow dry them to obtain SiO2 / Si sheets; ultrasonically clean the cut SiO2 / Si sheets in acetone, isopropyl alcohol, and deionized water for 15 minutes, and then blow dry them with nitrogen to obtain a usable SiO2 / Si substrate 1. The SiO2 substrate in the SiO2 / Si substrate 1 has a thickness of 280 nm and the Si substrate is lightly N-type doped silicon;

[0051] hBN crystal material, MoTe2 crystal material and MoS2 crystal material were respectively peeled off onto PDMS substrate by mechanical exfoliation method to form hBN nanosheets, MoTe2 nanosheets and MoS2 nanosheets;

[0052] Then, the hBN nanosheets on the PDMS substrate were transferred to the upper surface of the SiO2 / Si substrate 1 using a dry transfer technique to form a dielectric layer 2; the thickness of the dielectric layer 2 was 15 nm;

[0053] Then, the hBN nanosheets on the upper surface of the SiO2 / Si substrate 1 and the MoTe2 nanosheets on the PDMS substrate are found by a micro-focusing system, and the PDMS substrate with the MoTe2 nanosheets is transferred to the top of the hBN nanosheets. The PDMS substrate with the MoTe2 nanosheets is then lowered until it is completely attached to the upper surface of the hBN nanosheets, thereby obtaining the first MoTe2 layer 3.

[0054] The MoS2 nanosheets on the first MoTe2 layer 3 and the PDMS substrate are found separately by a micro-focusing system, and the PDMS substrate with the MoS2 nanosheets is transferred to the top of the first MoTe2 layer 3. The PDMS substrate with the MoS2 nanosheets is then lowered until it is completely attached to the upper surface of the first MoTe2 layer 3, thereby obtaining the first MoS2 layer 4.

[0055] Using a micro-focusing system, the first MoS2 layer 4 and the MoTe2 nanosheets on the PDMS substrate are found respectively, and the PDMS substrate with the MoTe2 nanosheets is transferred to the top of the first MoS2 layer 4. The PDMS substrate with the MoTe2 nanosheets is then lowered until it is completely attached to the upper surface of the first MoS2 layer 4, thereby obtaining a second MoTe2 layer 5.

[0056] The second MoTe2 layer 5 and the MoS2 nanosheets on the PDMS substrate are found separately by a micro-focusing system, and the PDMS substrate with the MoS2 nanosheets is transferred to the top of the second MoTe2 layer 5. The PDMS substrate with the MoS2 nanosheets is then lowered until it is completely attached to the upper surface of the second MoTe2 layer 5, thereby obtaining a second MoS2 layer 6.

[0057] The Au electrodes are transferred to the P-end and N-end of the heterojunction respectively as the source and drain to obtain a pre-processed part;

[0058] S2: The pre-treated piece is placed in an annealing furnace and annealed in an argon-hydrogen mixture (90% Ar / 10% H2) at 200°C for 30 minutes to obtain a double floating gate photodiode with a nearly ideal linear response.

[0059] Example 2

[0060] The difference from Example 1 is that the thickness of the SiO2 substrate in the SiO2 / Si substrate 1 is 300nm; the annealing temperature is 230°C, the annealing time is 40min, and the rest of the preparation process and parameters are the same as in Example 1, resulting in a dual floating gate photodiode with a nearly ideal linear response.

[0061] Comparative Example 1

[0062] The difference from Example 1 is that the preparation process of Comparative Example 1 does not include the step of transferring the second MoS2 layer, and the rest is the same as Example 1, obtaining a single floating gate MoTe2 / MoS2 van der Waals heterojunction photodiode.

[0063] Figure 3 The figure shows the short-circuit current (I) of the double floating gate photodiode with nearly ideal linear response under 532nm laser illumination. sc ), open circuit voltage (V oc ) with the incident light power (P in ), we can see that the short-circuit current and the incident light power density are nearly linear, indicating that the photocurrent and the light power are linearly related.

[0064] Figure 4 The graph shows the variation of photocurrent with incident light power of a double floating-gate MoTe2 / MoS2 van der Waals heterojunction photodiode with near-ideal linear response under incident light of different wavelengths (405nm, 532nm, 785nm, 1064nm, 1260nm, 1350nm, 1450nm, 1500nm, 1550nm and 1600nm), indicating that under illumination, a linear response with a wide linear dynamic range from visible light to near-infrared band is achieved.

[0065] Figure 5 The double floating gate photodiode of the present invention with nearly ideal linear response has a photocurrent (I ph ) versus incident light power. As shown in the figure, the photocurrent and light power show a good linear relationship under all applied gate voltages.

[0066] Figure 6 This is a multi-wavelength (405nm, 532nm, 785nm and 1064nm) imaging capability diagram of the dual floating-gate photodiode with near-ideal linear response of the present invention, indicating that the device can perform stable, high-resolution imaging at four different wavelengths.

[0067] Figure 7 This is the structural diagram of the single floating gate MoTe2 / MoS2 van der Waals heterojunction photodiode in comparative example 1. The device is composed of SiO2 / Si, hBN, MoTe2, MoS2, MoTe2, and Au electrodes from bottom to top.

[0068] Figure 8 The graph of the photocurrent of the single floating gate MoTe2 / MoS2 van der Waals heterojunction photodiode in comparative example 1 under 532nm laser illumination varies with the incident light power. Figure 4The comparison of the photocurrent variation with incident light power of the nearly ideal linear dual floating gate MoTe2 / MoS2 van der Waals heterojunction photodiode under 635nm laser illumination is shown. Figure 8 The linearity of comparative example 1 is far inferior to Figure 4 The linearity shown in Figure 2 indicates that the addition of the top floating layer more thoroughly depletes electrons in the MoTe2 channel, thereby weakening the interaction between majority and minority carriers and enhancing the separation of photogenerated electron-hole pairs, thereby improving the linearity of the photoelectric response and enhancing the photocurrent.

[0069] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A dual floating gate photodiode with nearly ideal linear response, characterized in that: The invention comprises a SiO2 / Si substrate (1), wherein a dielectric layer (2) is provided on the upper surface of the SiO2 / Si substrate (1); a first MoTe2 layer (3) as a bottom floating gate is provided on the upper surface of the dielectric layer (2); a first MoS2 layer (4) as an N-terminal is provided on the upper surface of the first MoTe2 layer (3); a second MoTe2 layer (5) as a P-terminal is provided on the upper surface of the first MoS2 layer (4); and a second MoS2 layer (6) as a top floating gate is provided on the upper surface of the second MoTe2 layer (5); One end of the first MoS2 layer (4) is in contact with the surface of the dielectric layer (2), and the other end is arranged on the upper surface of the first MoTe2 layer (3); one end of the second MoTe2 layer (5) is in contact with the surface of the dielectric layer, and the other end is in contact with the upper surface of the first MoS2 layer (4); Electrodes (7) are respectively provided on the upper surfaces of the first MoS2 layer (4) and the second MoTe2 layer (5) that are in contact with the surface of the dielectric layer.

2. The dual floating gate photodiode with near-ideal linear response according to claim 1, characterized in that: The material of the dielectric layer (2) is hBN.

3. The dual floating gate photodiode with near-ideal linear response according to claim 2, wherein: The thickness of the dielectric layer (2) is 14-20 nm.

4. The dual floating gate photodiode with near-ideal linear response according to claim 1, wherein: The material of the electrode (7) is gold, silver or palladium.

5. The dual floating gate photodiode with near-ideal linear response according to claim 4, characterized in that: The thickness of the electrode (7) is 45-50 nm.

6. The dual floating gate photodiode with near-ideal linear response according to claim 1, characterized in that: The SiO2 / Si substrate (1) comprises a SiO2 substrate and a Si substrate, wherein the SiO2 substrate is arranged on the upper surface of the Si substrate; the thickness of the SiO2 substrate is 280-300 nm.

7. The method for preparing a dual floating gate photodiode with a near-ideal linear response according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: The dielectric layer (2) is transferred to the upper surface of the SiO2 / Si substrate (1) by dry transfer technology; the first MoTe2 layer (3) is transferred to the upper surface of the dielectric layer (2) as a bottom floating gate by a fixed-point transfer method; then the first MoS2 layer (4) is transferred to the upper surface of the first MoTe2 layer (3) as the N end, wherein one end of the first MoS2 layer (4) contacts the upper surface of the dielectric layer (2) and the other end contacts the upper surface of the first MoTe2 layer (3); then the second MoT The e2 layer (5) is transferred to the upper surface of the first MoS2 layer (4) as the P terminal, wherein one end of the second MoTe2 layer (5) contacts the upper surface of the dielectric layer (2) and the other end contacts the upper surface of the first MoS2 layer (4); the second MoS2 layer (6) is transferred to the upper surface of the second MoTe2 layer (5) as the top floating gate; finally, the electrode (7) is respectively transferred to the upper surfaces of the first MoS2 layer (4) and the second MoTe2 layer (5) in contact with the upper surface of the dielectric layer (2) to obtain a pre-processed part; S2: Annealing the pre-treated component to obtain a dual floating gate photodiode with a nearly ideal linear response.

8. The method for preparing a dual floating gate photodiode with near-ideal linear response according to claim 7, wherein: The material of the dielectric layer (2) is hBN; the material of the electrode (7) is Au; During preparation The following steps are involved: S1: hBN crystal material, MoTe2 crystal material and MoS2 crystal material are respectively peeled off onto the PDMS substrate by mechanical exfoliation method to form hBN nanosheets, MoTe2 nanosheets and MoS2 nanosheets; Then, the hBN nanosheets on the PDMS substrate are transferred to the upper surface of the SiO2 / Si substrate (1) using a dry transfer technique to form a dielectric layer (2); Then, the hBN nanosheets on the upper surface of the SiO2 / Si substrate (1) and the MoTe2 nanosheets on the PDMS substrate are found by the micro-focusing system, and the PDMS substrate with the MoTe2 nanosheets is transferred to the top of the hBN nanosheets. Then, the PDMS substrate with the MoTe2 nanosheets is lowered until it is completely attached to the upper surface of the hBN nanosheets, thereby obtaining the first MoTe2 layer (3). Using a microscopic focusing system, the first MoTe2 layer (3) and the MoS2 nanosheets on the PDMS substrate are found respectively, and the PDMS substrate with the MoS2 nanosheets is transferred to the top of the first MoTe2 layer (3), and then the PDMS substrate with the MoS2 nanosheets is lowered until it is completely attached to the upper surface of the first MoTe2 layer (3), thereby obtaining the first MoS2 layer (4); Using a microscopic focusing system, the first MoS2 layer (4) and the MoTe2 nanosheets on the PDMS substrate are found respectively, and the PDMS substrate with the MoTe2 nanosheets is transferred to the top of the first MoS2 layer (4), and then the PDMS substrate with the MoTe2 nanosheets is lowered until it is completely attached to the upper surface of the first MoS2 layer (4), thereby obtaining a second MoTe2 layer (5); The second MoTe2 layer (5) and the MoS2 nanosheets on the PDMS substrate are found by a micro-focusing system, and the PDMS substrate with the MoS2 nanosheets is transferred to the top of the second MoTe2 layer (5), and then the PDMS substrate with the MoS2 nanosheets is lowered until it is completely attached to the upper surface of the second MoTe2 layer (5), thereby obtaining a second MoS2 layer (6); Transferring the electrodes (7) to the upper surfaces of the first MoS2 layer (4) and the second MoTe2 layer (5) respectively, which are in contact with the upper surface of the dielectric layer (2), to obtain a pre-processed part; S2: Annealing the pre-treated component to obtain a dual floating gate photodiode with a nearly ideal linear response.

9. The method for preparing a dual floating gate photodiode with a near-ideal linear response according to claim 8, wherein: The annealing treatment is performed in a mixed gas of argon and hydrogen, the annealing treatment temperature is 200-230° C., and the annealing treatment time is 30-40 minutes.

10. The method for preparing a dual floating gate photodiode with nearly ideal linear response according to claim 9, characterized in that: The volume ratio of argon to hydrogen in the mixed gas of argon and hydrogen is 9:1.

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