Two-dimensional high-speed photoelectric detector with vertical structure and preparation method and application of two-dimensional high-speed photoelectric detector

Abstract

The invention provides a vertical-structure two-dimensional high-speed photoelectric detector and a preparation method and application thereof, and belongs to the technical field of photoelectric devices. The invention provides a two-dimensional high-speed photoelectric detector with a vertical structure. The two-dimensional high-speed photoelectric detector comprises a substrate, a metal bottom electrode layer, a two-dimensional semiconductor material layer and an indium tin oxide layer which are sequentially stacked. The invention provides a vertical-structure two-dimensional high-speed photoelectric detector with an optical microcavity. The microcavity is composed of an indium tin oxide layer, a two-dimensional semiconductor material layer and a metal bottom electrode layer. The prepared photoelectric detector has the advantages of high response speed and high responsivity, and the preparation method is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a vertical structure two-dimensional high-speed photoelectric detector and a preparation method and application thereof. Background Art

[0002] Since the first two-dimensional material graphene was exfoliated from highly oriented pyrolytic graphite by mechanical exfoliation in 2004, two-dimensional materials have grown into a large family system that includes more than 100 materials. As a new type of semiconductor material, two-dimensional materials have many excellent optoelectronic properties, including a wide range of light absorption, high carrier mobility, and no influence of lattice mismatch.

[0003] Among two-dimensional materials, transition metal chalcogenides are the most widely used. They have rich and adjustable band structures, and their surfaces are naturally passivated, which avoids the generation of leakage current. They are considered to be extremely promising electronic and optoelectronic materials. However, most traditional two-dimensional photodetectors adopt a lateral structure design, and their micron-level channel width requires photogenerated carriers to undergo a long transport process. This feature not only limits the drift velocity of carriers and increases the recombination probability, but also causes the response time of the device to generally remain in the millisecond level. This performance bottleneck significantly restricts the application potential of such devices in high-speed photodetection fields such as high-frequency optical communications and ultrafast imaging, and it is difficult to meet the needs of modern high-speed photodetection. Usually, two-dimensional photodetectors have weak light response due to high carrier recombination rate and low collection efficiency. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a vertical structure two-dimensional high-speed photodetector and its preparation method and application. The vertical structure two-dimensional high-speed photodetector based on microcavity enhancement effect provided by the present invention has a high response speed and a large responsivity.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a vertical structure two-dimensional high-speed photoelectric detector, comprising a substrate, a metal bottom electrode layer, a two-dimensional semiconductor material layer and an indium tin oxide layer which are stacked in sequence.

[0007] Preferably, the thickness of the two-dimensional semiconductor material layer is 20-200 nm.

[0008] Preferably, the material of the two-dimensional semiconductor material layer includes transition metal chalcogenide.

[0009] Preferably, the transition metal chalcogenide compound includes one or more of molybdenum disulfide, tungsten disulfide and tungsten diselenide.

[0010] Preferably, the thickness of the indium tin oxide layer is 10 - 100 nm.

[0011] Preferably, the metal bottom electrode layer includes a chromium metal layer and a gold metal layer which are stacked, and the chromium metal layer is loaded on the surface of the substrate.

[0012] Preferably, the thickness of the chromium metal layer is 3 - 15 nm, and the thickness of the gold metal layer is 40 - 100 nm.

[0013] Preferably, the substrate is a silicon / silicon dioxide substrate, the thickness of the silicon layer in the silicon / silicon dioxide substrate is 500 μm, the thickness of the silicon dioxide layer is 280 - 300 nm, and the metal bottom electrode layer is loaded on the surface of the silicon dioxide layer.

[0014] The present invention also provides a preparation method of the vertical structure two-dimensional high-speed photodetector described in the above technical solution, including the following steps:

[0015] Form a metal bottom electrode layer on the substrate by deposition;

[0016] Transfer the two-dimensional semiconductor material onto the metal bottom electrode layer to form a two-dimensional semiconductor material layer;

[0017] Deposit on the surface of the two-dimensional semiconductor material layer to form an indium tin oxide layer, and obtain the vertical structure two-dimensional high-speed photodetector.

[0018] The present invention also provides an application of the vertical structure two-dimensional high-speed photodetector described in the above technical solution in high-speed optoelectronic devices.

[0019] The present invention provides a vertical structure two-dimensional high-speed photodetector, including a substrate, a metal bottom electrode layer, a two-dimensional semiconductor material layer, and an indium tin oxide layer which are sequentially stacked.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] In the present invention, the metal bottom electrode layer is a total reflection layer, the two-dimensional semiconductor material layer is an optical absorption layer with adjustable thickness, and the indium tin oxide layer is a transmissive top electrode. The present invention provides a vertical structure two-dimensional high-speed photodetector with an optical microcavity, wherein the microcavity is composed of the indium tin oxide layer, the two-dimensional semiconductor material layer, and the metal bottom electrode layer. The optical response of the photodetector is enhanced by multiple reflections of incident light in the microcavity, improving the optical response speed and responsivity. The channel width of the vertical structure two-dimensional high-speed photodetector is determined by the thickness of the optical absorption layer. Compared with the lateral structure photodetector, the channel width is extremely narrow, and the carrier transit time is extremely short. Therefore, the response speed is extremely fast. The vertical structure two-dimensional high-speed photodetector of the present invention has the advantages of fast response speed and high responsivity, which is beneficial to the application of high-speed photodetectors.

[0022] The present invention also provides a preparation method of the vertical structure two-dimensional high-speed photodetector described in the above technical solution. The preparation method of the present invention is simple to operate and easy to industrialize. Description of the Drawings

[0023] Figure 1 It is a schematic cross-sectional structure diagram of the vertical structure two-dimensional high-speed photodetector obtained in Example 1;

[0024] Figure 2 It is a top view of the vertical structure two-dimensional high-speed photodetector obtained in Example 1;

[0025] Figure 3 It is an optical microscope image of the vertical structure two-dimensional high-speed photodetector obtained in Example 1;

[0026] Figure 4 It is a current-voltage curve diagram of the vertical structure two-dimensional high-speed photodetector obtained in Example 1 in the dark state;

[0027] Figure 5 It is a transient response test diagram of the vertical structure two-dimensional high-speed photodetector obtained in Example 1 under the incidence of a 520 nm laser;

[0028] Figure 6 It is a power-dependent photocurrent response characteristic diagram of the vertical structure two-dimensional high-speed photodetector obtained in Example 1 under the incidence of a 630 nm laser;

[0029] Figure 7 It is obtained from Example 1 by Figure 6 The responsivity test diagram of the vertical structure two-dimensional high-speed photodetector obtained by calculation under the incidence of a 630 nm laser at different optical powers;

[0030] Figure 8 It is a current-voltage curve diagram of the vertical structure two-dimensional high-speed photodetector obtained in Example 2 in the dark state;

[0031] Figure 9 It is a transient response test diagram of the vertical structure two-dimensional high-speed photodetector obtained in Example 2 under the incidence of a 520 nm laser;

[0032] Figure 10 It is a power-dependent photocurrent response characteristic diagram of the vertical structure two-dimensional high-speed photodetector obtained in Example 2 under the incidence of a 630 nm laser;

[0033] Figure 11 It is obtained from Example 2 by Figure 10 The responsivity test diagram of the vertical structure two-dimensional high-speed photodetector obtained by calculation under the incidence of a 630 nm laser at different optical powers;

[0034] Figures 1 - 3 Among them, 1 is a silicon / silicon dioxide substrate, 2 is a metal bottom electrode layer, 3 is a tungsten disulfide thin sheet, and 4 is an indium tin oxide layer. Specific embodiments

[0035] The present invention provides a vertical structure two-dimensional high-speed photodetector, including a substrate, a metal bottom electrode layer, a two-dimensional semiconductor material layer, and an indium tin oxide layer that are sequentially stacked.

[0036] In the present invention, the substrate is preferably a silicon / silicon dioxide substrate. The thickness of the silicon layer in the silicon / silicon dioxide substrate is preferably 500 μm, and the thickness of the silicon dioxide layer is preferably 280 - 300 nm, specifically 280, 290, or 300 nm. The metal bottom electrode layer is preferably loaded on the surface of the silicon dioxide layer.

[0037] In the present invention, the size of the silicon / silicon dioxide substrate is preferably 0.5 - 0.7 cm × 0.5 - 0.7 cm.

[0038] In the present invention, the metal bottom electrode layer preferably includes a stacked chromium metal layer and a gold metal layer. The chromium metal layer is preferably loaded on the surface of the substrate.

[0039] In the present invention, the thickness of the chromium metal layer is preferably 3 - 15 nm, more preferably 5 - 12 nm, and even more preferably 7 - 10 nm. The thickness of the gold metal layer is preferably 40 - 100 nm, more preferably 56 - 84 nm, and even more preferably 65 - 75 nm, specifically 65, 70, 75, or 80 nm.

[0040] In the present invention, the metal bottom electrode layer is preferably "T"-shaped, more preferably including an end region and a middle region. The end region is the vertical part for contact. Both the end region and the middle region are provided on the surface of the substrate. The middle region is the horizontal part for easy testing. In the present invention, the size of the end region is preferably 30 - 100 μm × 30 - 100 μm. In the present invention, the width of the middle region is preferably 0.5 - 0.8 mm, specifically 0.5, 0.6, 0.7, or 0.8 mm. The present invention has no special limitation on the length of the middle region, as long as it is less than the length of the substrate and does not contact the indium tin oxide layer. In a specific embodiment of the present invention, the length of the middle region is preferably 0.5 mm.

[0041] In the present invention, the thickness of the two-dimensional semiconductor material layer is preferably 20 - 200 nm, more preferably 40 - 160 nm, still more preferably 55 - 110 nm, and specifically can be 59.7 or 102.8 nm; the thickness of the two-dimensional semiconductor material layer is equal to the cavity thickness of the optical microcavity.

[0042] In the present invention, the material of the two-dimensional semiconductor material layer preferably includes transition metal chalcogenides.

[0043] In the present invention, the transition metal chalcogenides preferably include one or more of molybdenum disulfide, tungsten disulfide, and tungsten diselenide.

[0044] In the present invention, the thickness of the indium tin oxide layer is preferably 10 - 100 nm, more preferably 40 - 70 nm, still more preferably 50 - 60 nm.

[0045] In the present invention, the indium tin oxide layer is preferably cubic in shape. In the present invention, the length and width of the indium tin oxide layer are preferably 30 - 100 μm × 30 - 100 μm, and specifically can be 50 μm × 50 μm or 60 μm × 60 μm.

[0046] In the present invention, the two-dimensional semiconductor material layer, the metal bottom electrode layer, and the indium tin oxide layer form an optical microcavity, achieving enhanced light response of the vertical structure two-dimensional high-speed photodetector.

[0047] In the present invention, the cavity thickness of the optical microcavity is preferably the response wavelength / 4 × refractive index.

[0048] In the present invention, the response wavelength is preferably 405 - 800 nm.

[0049] The present invention also provides a method for preparing the vertical structure two-dimensional high-speed photodetector according to the above technical solution, including the following steps:

[0050] Deposit on a substrate to form a metal bottom electrode layer;

[0051] Transfer a two-dimensional semiconductor material onto the metal bottom electrode layer to form a two-dimensional semiconductor material layer;

[0052] Deposit on the surface of the two-dimensional semiconductor material layer to form an indium tin oxide layer, obtaining the vertical structure two-dimensional high-speed photodetector.

[0053] In the present invention, deposit on a substrate to form a metal bottom electrode layer.

[0054] In the present invention, the substrate is preferably cleaned before use, and the cleaning preferably includes sequentially using acetone, isopropyl alcohol, and deionized water.

[0055] The present invention preferably uses electron beam lithography technology to expose the metal bottom electrode region on the substrate and perform development processing, then sequentially evaporates chromium and gold using a thermal evaporation device to obtain the metal bottom electrode layer, and finally uses acetone, isopropyl alcohol, and deionized water to strip the remaining photoresist in sequence.

[0056] In the present invention, the preparation method of the metal bottom electrode layer is preferably thermal evaporation deposition. In the present invention, the deposition rate of the thermal evaporation deposition is preferably independently 0.1 to 0.5 Å / s, specifically it can be 0.1, 0.2, 0.3, 0.4, or 0.5 Å / s. The present invention has no special limitation on the process of the thermal evaporation deposition, and the process well-known to those skilled in the art can be adopted.

[0057] In a specific embodiment of the present invention, the preparation of the metal bottom electrode layer preferably includes the following steps: using electron beam lithography technology to expose the metal bottom electrode region on the silicon / silicon dioxide substrate and perform development processing, and then sequentially depositing a chromium metal layer and a gold metal layer by means of thermal evaporation deposition.

[0058] After forming the metal bottom electrode layer, the present invention transfers the two-dimensional semiconductor material onto the metal bottom electrode layer to form a two-dimensional semiconductor material layer.

[0059] In the present invention, the preparation of the two-dimensional semiconductor material preferably includes the following steps: using the mechanical exfoliation method to exfoliate a two-dimensional semiconductor material with uniform thickness and flat surface from a bulk transition metal chalcogenide crystal.

[0060] The present invention preferably first transfers the two-dimensional semiconductor material onto polydimethylsiloxane, and then transfers the two-dimensional semiconductor material from the polydimethylsiloxane onto the metal bottom electrode layer on the transfer stage.

[0061] The present invention has no special limitation on the mechanical exfoliation method and the transfer process, and the process well-known to those skilled in the art can be adopted.

[0062] In the present invention, it is preferred to transfer the two-dimensional semiconductor material to the end region of the metal bottom electrode layer to form the two-dimensional semiconductor material layer.

[0063] After forming the two-dimensional semiconductor material layer, the present invention deposits on the surface of the two-dimensional semiconductor material layer to form an indium tin oxide layer, thereby obtaining the vertical structure two-dimensional high-speed photodetector.

[0064] In the present invention, the preparation method of the indium tin oxide layer is preferably magnetron sputtering deposition or ion beam sputtering deposition; the deposition rate of the magnetron sputtering deposition or ion beam sputtering deposition is independently preferably 0.1 to 0.5 Å / s, specifically it can be 0.1, 0.2, 0.3, 0.4 or 0.5 Å / s. The present invention has no special limitation on the process of the magnetron sputtering deposition or ion beam sputtering deposition, and the process well-known to those skilled in the art can be adopted.

[0065] In a specific embodiment of the present invention, the preparation of the indium tin oxide layer preferably includes the following steps:

[0066] Using electron beam lithography technology to expose the indium tin oxide top electrode area on the two-dimensional semiconductor material layer and perform development treatment, using magnetron sputtering deposition or ion beam sputtering deposition to prepare the indium tin oxide layer, and finally sequentially using acetone, isopropyl alcohol and deionized water to strip the remaining photoresist to obtain the vertical structure two-dimensional high-speed photodetector.

[0067] The present invention also provides the application of the vertical structure two-dimensional high-speed photodetector described in the above technical solution in high-speed optoelectronic devices.

[0068] The present invention has no special limitation on the specific implementation manner of the application, and the process well-known to those skilled in the art can be adopted.

[0069] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0070] Example 1

[0071] Successively use acetone, isopropyl alcohol and deionized water to clean the silicon / silicon dioxide substrate (where the thickness of the silicon layer is 500 μm, the thickness of the silicon dioxide layer is 280 nm, and the substrate size is 0.6 cm × 0.6 cm) to obtain the cleaned silicon / silicon dioxide substrate;

[0072] Use electron beam lithography technology to expose the metal bottom electrode area on the cleaned silicon / silicon dioxide substrate and perform development treatment, and then use thermal evaporation deposition to sequentially deposit a chromium metal layer with a thickness of 10 nm and a gold metal layer with a thickness of 70 nm, and the deposition rates are both 0.3 Å / s to obtain the metal bottom electrode layer (where the size of the end area is 50 μm × 50 μm, and the length of the middle area is 0.5 mm and the width is 0.5 mm), and then successively use acetone, isopropyl alcohol and deionized water to strip the remaining photoresist;

[0073] Using the mechanical exfoliation method, a tungsten disulfide thin sheet with uniform thickness and flat surface (thickness of 102.8 nm) was exfoliated from a bulk tungsten disulfide crystal, and then the tungsten disulfide thin sheet was transferred onto the cut polydimethylsiloxane;

[0074] The metal bottom electrode layer was fixed on the transfer stage, and the tungsten disulfide thin sheet was transferred from the polydimethylsiloxane onto the metal bottom electrode layer;

[0075] Again, using electron beam lithography technology, the indium tin oxide top electrode region was exposed on the tungsten disulfide thin sheet and developed, and then an indium tin oxide layer with a thickness of 50 nm (length and width dimensions of 50 μm × 50 μm) was deposited by ion beam sputtering deposition at a deposition rate of 0.3 Å / s. Then, acetone, isopropyl alcohol, and deionized water were used in sequence to strip the remaining photoresist, obtaining the vertical structure two-dimensional high-speed photodetector; the schematic cross-sectional structure diagram of the obtained vertical structure two-dimensional high-speed photodetector is as Figure 1 shown, and the top view of the obtained vertical structure two-dimensional high-speed photodetector is as Figure 2 shown. Figure 3 is the optical microscope image of the vertical structure two-dimensional high-speed photodetector obtained in Example 1. Figures 1 - 3 In it, 1 is the silicon / silicon dioxide substrate, 2 is the metal bottom electrode layer, 3 is the tungsten disulfide thin sheet, and 4 is the indium tin oxide layer.

[0076] Figure 4 is the dark state voltage-current curve graph of the vertical structure two-dimensional high-speed photodetector obtained in Example 1. From Figure 4 it can be seen that under the working condition of an applied voltage of 0 V, the vertical structure two-dimensional high-speed photodetector provided by the present invention has an extremely low dark current, as low as 10 -11 A magnitude.

[0077] Figure 5 is the transient response test graph of the vertical structure two-dimensional high-speed photodetector obtained in Example 1 under the incidence of a 520 nm laser. From Figure 5 it can be seen that under the working conditions of an applied voltage of 0 V and an incident laser wavelength of 520 nm, the rise and fall times of the vertical structure two-dimensional high-speed photodetector are 404 ns and 24 ns respectively, indicating its application prospects in the field of high-speed photodetector devices.

[0078] Figure 6 is the power-dependent photocurrent response characteristic graph of the vertical structure two-dimensional high-speed photodetector obtained in Example 1 under the incidence of a 630 nm laser. From Figure 6It can be seen that under the working conditions of an applied voltage of 0 V and an incident laser wavelength of 630 nm, the linear correlation coefficient between the photocurrent and the incident optical power is 0.94, showing excellent linear response characteristics dependent on power.

[0079] Figure 7 For the vertical structure two-dimensional high-speed photodetector obtained in Example 1 from Figure 6 The responsivity test chart at different optical powers obtained when the vertical structure two-dimensional high-speed photodetector is irradiated with 630 nm laser calculated from Figure 7 It can be seen that under the enhancement effect of the optical microcavity, when the incident laser wavelength of the vertical structure two-dimensional high-speed photodetector is 630 nm and the applied voltage is 0 V, the optical responsivity reaches the highest value of 375 mA / W at an optical power of 0.4 μW.

[0080] Example 2

[0081] The silicon / silicon dioxide substrate (where the silicon layer thickness is 500 μm, the silicon dioxide layer thickness is 280 nm, and the substrate size is 0.6 cm × 0.6 cm) is cleaned successively with acetone, isopropanol, and deionized water to obtain the cleaned silicon / silicon dioxide substrate;

[0082] The metal bottom electrode area is exposed on the cleaned silicon / silicon dioxide substrate using electron beam lithography technology and developed, and then a chromium metal layer with a thickness of 15 nm and a gold metal layer with a thickness of 80 nm are deposited successively by thermal evaporation deposition at a deposition rate of 0.3 Å / s to obtain the metal bottom electrode layer (where the size of the end area is 70 μm × 70 μm, and the length of the middle area is 0.5 mm and the width is 0.6 mm);

[0083] A tungsten disulfide thin sheet with uniform thickness and flat surface (thickness of 59.7 nm) is exfoliated from a bulk tungsten disulfide crystal using the mechanical exfoliation method, and then the tungsten disulfide thin sheet is transferred to the cut polydimethylsiloxane;

[0084] The metal bottom electrode layer is fixed on the transfer stage, and the tungsten disulfide thin sheet is transferred from the polydimethylsiloxane to the metal bottom electrode layer;

[0085] The indium tin oxide top electrode area is exposed on the tungsten disulfide thin sheet again using electron beam lithography technology and developed, and then an indium tin oxide layer with a thickness of 60 nm (length and width dimensions of 60 μm × 60 μm) is deposited by ion beam sputtering deposition at a deposition rate of 0.3 Å / s to obtain the vertical structure two-dimensional high-speed photodetector.

[0086] Figure 8 The dark state voltage-current curve graph of the vertical structure two-dimensional high-speed photodetector obtained in Example 2, fromFigure 8 It can be seen that under the working condition of an applied voltage of 0 V, the vertical-structure two-dimensional high-speed photodetector provided by the present invention has an extremely low dark current, as low as 10 -11 in the order of magnitude of A.

[0087] Figure 9 Fig. is the transient response test diagram of the vertical-structure two-dimensional high-speed photodetector obtained in Example 2 under the incidence of a 520-nm laser. From Figure 9 it can be seen that under the working conditions of an applied voltage of 0 V and an incident laser wavelength of 520 nm, the rise and fall times of the vertical-structure two-dimensional high-speed photodetector are 430 ns and 20 ns respectively, indicating its application prospects in the field of high-speed photodetection devices.

[0088] Figure 10 Fig. is the power-dependent photocurrent response characteristic diagram of the vertical-structure two-dimensional high-speed photodetector obtained in Example 2 under the incidence of a 630-nm laser. From Figure 10 it can be seen that under the working conditions of an applied voltage of 0 V and an incident laser wavelength of 630 nm, the linear correlation coefficient between its photocurrent and the incident optical power is 0.87, showing excellent power-dependent linear response characteristics.

[0089] Figure 11 Fig. is the responsivity test diagram of the vertical-structure two-dimensional high-speed photodetector obtained in Example 2 at different optical powers under the incidence of a 630-nm laser, which is Figure 10 calculated. From Figure 11 it can be seen that under the enhancement effect of the optical microcavity, under the working conditions of an incident laser wavelength of 630 nm and an applied voltage of 0 V, the optical responsivity of the vertical-structure two-dimensional high-speed photodetector reaches the highest value of 14 mA / W at an optical power of 4.45 μW.

[0090] The above is only the preferred embodiment of the present invention and does not impose any form of limitation on the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A vertical-structure two-dimensional high-speed photodetector, characterized in that, It includes a substrate, a metal bottom electrode layer, a two-dimensional semiconductor material layer, and an indium tin oxide layer that are sequentially stacked.

2. The vertical-structure two-dimensional high-speed photodetector according to claim 1, wherein The thickness of the two-dimensional semiconductor material layer is 20 - 200 nm.

3. The vertical structure two-dimensional high-speed photodetector according to claim 1 or 2, characterized in that, The material of the two-dimensional semiconductor material layer includes transition metal chalcogenides.

4. The vertical-structure two-dimensional high-speed photodetector according to claim 3, wherein The transition metal chalcogenides include one or more of molybdenum disulfide, tungsten disulfide, and tungsten diselenide.

5. The vertical structure two-dimensional high-speed photodetector according to claim 1, wherein The thickness of the indium tin oxide layer is 10 - 100 nm.

6. The vertical-structure two-dimensional high-speed photodetector according to claim 1, wherein The metal bottom electrode layer includes a chromium metal layer and a gold metal layer that are stacked, and the chromium metal layer is loaded on the surface of the substrate.

7. The vertical-structure two-dimensional high-speed photodetector according to claim 6, characterized in that The thickness of the chromium metal layer is 3 - 15 nm, and the thickness of the gold metal layer is 40 - 100 nm.

8. The vertical structure two-dimensional high-speed photodetector according to claim 1, wherein The substrate is a silicon / silicon dioxide substrate. The thickness of the silicon layer in the silicon / silicon dioxide substrate is 500 μm, and the thickness of the silicon dioxide layer is 280 - 300 nm. The metal bottom electrode layer is loaded on the surface of the silicon dioxide layer.

9. The preparation method of the vertical-structure two-dimensional high-speed photodetector according to any one of claims 1 to 8, characterized in that, It includes the following steps: Form a metal bottom electrode layer on the substrate by deposition. Transfer the two-dimensional semiconductor material onto the metal bottom electrode layer to form a two-dimensional semiconductor material layer. Deposit on the surface of the two-dimensional semiconductor material layer to form an indium tin oxide layer, and obtain the vertical structure two-dimensional high-speed photodetector.

10. Application of the vertical structure two-dimensional high-speed photodetector according to claim 9 in high-speed optoelectronic devices.

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