Photoelectric detection heterojunction, photoelectric detection device and preparation method and application thereof

Abstract

The invention discloses a photoelectric detection heterojunction, a photoelectric detection device and a preparation method and application thereof. The photoelectric detection heterojunction comprises a Van der Waals heterojunction formed by stacking a black phosphorus layer and a second-type Weel semimetal material layer. According to the technical scheme provided by the invention, the Van der Waals heterojunction photodetector based on black phosphorus-second class of Weel semimetal (BP-II WSM) is constructed, and the influence of parameters such as different types of II WSM materials, device structures, external electric fields, excitation light wavelengths and energy on device performances such as detection range, responsivity, response speed, quantum efficiency and detection rate is researched. The BP-II WSM Van der Waals heterojunction infrared photoelectric detector which has the excellent performance of giving consideration to broadband response, especially aiming at far infrared bands, being high in room temperature responsivity, high in response speed and the like is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-nano electronic and optoelectronic devices, and particularly relates to a photoelectric detection heterojunction, a photoelectric detection device and a preparation method and application thereof. BACKGROUND

[0002] Infrared photoelectric detectors are widely used in many important fields of national economy and national defense industry, including remote sensing, industrial automatic control, medical treatment, environmental monitoring, infrared imaging, missile guidance, military communication, etc., and have become one of the hotspots of research and development in the field of national defense and industry. High-performance infrared photoelectric detectors rely on photosensitive materials with sensitive response to long-wave and very long-wave and high mobility.

[0003] Traditional infrared photoelectric detectors include photoconductive quantum well materials of GaAs / AlGaAs system and photovoltaic quantum well materials of InAs / InGaSb and InAs / InAsSb system, and narrow-bandgap semiconductor materials represented by III-V compound, although these traditional semiconductor materials are currently internationally recognized as infrared detection materials with relatively ideal performance, and many technologies have gone from the laboratory to practical application, but there are also some shortcomings and deficiencies, mainly including: first, generally relying on low-temperature operation, resulting in high use cost, complex operation and strong environmental dependence; second, limited by the band gap, the photoelectric detection capability of traditional semiconductor materials can only cover the near-infrared wavelength region, and the detection capability in the far-infrared wavelength band is limited. In addition, the traditional semiconductor material photoelectric detector also has the limitations of low photon utilization rate, toxic materials, complex processing technology, and difficulty in meeting the needs of flexible wearable devices, making it more and more difficult to meet the development requirements of the next generation of high-performance new infrared photoelectric detectors.

[0004] In recent years, two-dimensional semiconductor materials as a new type of atomic layer crystal, due to its excellent physical properties, in the application of photoelectric detector shows outstanding potential and irreplaceable advantages: rich energy band structure, so that the detection response wavelength can cover the ultraviolet to far infrared; two-dimensional material and infrared detector based on two-dimensional material heterojunction at room temperature can realize high light response and high detection rate; perfect atomic crystal structure makes it has high carrier mobility; surface without dangling bond makes it easy to integrate with other materials. Graphene is the most representative two-dimensional semiconductor material in the world, due to its zero band gap characteristics, so that the graphene photoelectric detector has wide band detection range, ultrafast response speed. However, the higher dark current and lower light absorption rate lead to the low photoelectric response of graphene. Transition metal dichalcogenide (TMDs) material has intrinsic band gap and high light absorption rate, which can effectively suppress the dark current and improve the response of photoelectric detector. However, the narrow band gap (1.2-1.8eV) of TMDs material leads to its detection range covering only to near infrared band, and the lower carrier mobility also leads to its slower response speed. Therefore, the application development of two-dimensional material in photoelectric detector needs to consider both wide band coverage and high photoelectric response performance.

[0005] Black phosphorus (BP) has a tunable direct band gap (0.3-1.5eV) with thickness, which fills the gap between graphene and TMDs, so that black phosphorus can cover a wider detection wavelength range from visible light to mid-infrared band. In addition, black phosphorus has excellent carrier transport characteristics, with a room temperature hole mobility of more than 103cm2 / Vs, which is much higher than that of other two-dimensional materials such as TMDs, which is beneficial to the transport of photo-generated carriers and the acquisition of high response speed. However, due to the limitation of band gap, the detection range of black phosphorus can only cover the mid-infrared band (~4μm), which limits its detection ability in the far-infrared band.

[0006] Type-II Weyl topological semimetals (II WSMs) are a novel class of topological quantum state materials characterized by unique magnetotransport properties, a topologically nontrivial zero-bandgap structure, and ultrahigh carrier mobility resulting from the linear dispersion relation of energy bands in three-dimensional momentum space. Their extremely broad spectral absorption range makes them promising candidates for overcoming the limitations of conventional photodetectors and promising applications in broadband infrared photodetection, presenting new opportunities for improving photodetector performance. Although only a small number of type-II Weyl semimetals have been studied as photosensitive materials for optoelectronic devices, some groundbreaking advances have been made in the field of photodetection. Their zero bandgap and high carrier mobility endow type-II Weyl semimetals with ultrawide spectral detection and fast response, offering promising applications in room-temperature broadband photodetection, particularly in the mid- and far-infrared regions. However, the zero bandgap nature of Weyl semimetals leads to significant dark current even at low external bias voltages, and their quantum efficiency is low. These drawbacks limit device performance, particularly the on / off ratio and responsivity.

[0007] The second type of Weyl semimetal photodetectors reported above are mostly photoconductive. These devices are prone to rapid recombination of photogenerated carriers in the transmission channel, resulting in high dark current and low quantum efficiency, limiting their response performance. Therefore, there is a strong demand for fast charge separation mechanisms in semimetal materials. Generally speaking, excellent photodetectors should have high responsivity, wide-band response, room-temperature response, and fast response speed, but these are difficult to achieve with either a single two-dimensional material or a single semimetal. Summary of the Invention

[0008] In view of the deficiencies in the prior art, the present invention aims to provide a photoelectric detection heterojunction, a photoelectric detection device, and a preparation method and application thereof.

[0009] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0010] In a first aspect, the present invention provides a photodetection heterojunction comprising a van der Waals heterojunction formed by stacking a black phosphorus layer and a second-type Weyl semimetal material layer.

[0011] In a second aspect, the present invention further provides a photodetection device comprising the above-mentioned photodetection heterojunction, a first electrode, and a second electrode;

[0012] The first electrode is in electrical contact with the black phosphorus layer in the photodetection heterojunction, and the second electrode is in electrical contact with the second type Weyl semi-metal material layer in the photodetection heterojunction.

[0013] In a third aspect, the present invention further provides a method for preparing a photoelectric detection device, comprising:

[0014] obtaining an independent black phosphorus layer and a second type of Weyl semimetal material layer through micro-peeling;

[0015] forming a photoelectric detection heterojunction by sequentially stacking the black phosphorus layer and the second type of Weyl semimetal material layer on the surface of the substrate through dry transfer;

[0016] forming a first electrode and a second electrode at corresponding positions on the surface of the substrate to obtain a photoelectric detection device.

[0017] In a fourth aspect, the present application also provides the application of the photoelectric detection device in the photoelectric detection in the far infrared wave band.

[0018] Based on the above technical solution, compared with the prior art, the beneficial effects of the present application at least include:

[0019] The technical solution provided by the present application constructs a van der Waals heterojunction photo detector based on black phosphorus-second type of Weyl semimetal (BP-II WSM), studies the influence of different types of II WSM materials, device structures, applied electric fields, excitation light wavelengths and energy parameters on the device performance such as detection range, responsivity, response speed, quantum efficiency and detection rate, and obtains a BP-II WSM van der Waals heterojunction infrared photoelectric detector with excellent performance such as wide wave band response (especially for far infrared wave band), high responsivity at room temperature, and fast response speed.

[0020] The above description is only a summary of the technical solution of the present application, in order to enable those skilled in the art to more clearly understand the technical means of the present application, and can be implemented according to the content of the description, as follows. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a band structure schematic diagram of a black phosphorus layer and a second type of Weyl semimetal material layer in different contact states and light states provided by a typical embodiment of the present application;

[0022] Figure 2 is a construction and testing process schematic diagram of a photoelectric detection device provided by a typical embodiment of the present application;

[0023] Figure 3 is a structure schematic diagram of a photoelectric detection device provided by a typical embodiment of the present application. DETAILED DESCRIPTION

[0024] In view of the deficiencies in the prior art, the present inventors have long-term research and a large number of practices, and have proposed the technical solution of the present application. The technical solution, its implementation process and principles will be further explained as follows.

[0025] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description.

[0026] Moreover, the term "exemplary" is used herein to mean serving as an example, instance, or illustration. Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0027] As shown in FIG. 1, the present application provides a photodetector heterojunction, which includes a van der Waals heterojunction formed by stacking a black phosphorus layer and a second type of Weyl semimetal material layer. Figures 1-3

[0028] As to the specific material selection, in some embodiments, the second type of Weyl semimetal material layer includes any one of WTe2 (tungsten ditelluride), MoTe2 (molybdenum ditelluride), TaIrTe4 (tantalum iridium telluride), TaRhTe4 (tantalum rhodium telluride), TaRuTe4 (tantalum ruthenium telluride), NbIrTe4 (niobium iridium telluride), or a combination of two or more thereof, and is not limited thereto.

[0029] As to the structural size, in some embodiments, the thickness of the black phosphorus layer can be 5-100 nm.

[0030] In some embodiments, the thickness of the second type of Weyl semimetal material layer can be 10-100 nm.

[0031] Based on the material characteristics and structural characteristics of the above heterojunction, in some embodiments, the response wavelength of the infrared photodetector heterojunction is in the far infrared band.

[0032] The heterojunction photovoltaic device with built-in electric field is more advantageous than the photoconductive device in terms of dark current and noise suppression, and can obtain a better detection response signal-to-noise ratio. By constructing a van der Waals (vdW) heterojunction, the noise of infrared detection can be reduced due to the absence of surface dangling bonds. Another advantage is that the two materials can be stacked into a heterojunction without considering the stringent conditions such as lattice matching. On the one hand, the advantages of the two materials can be combined, and on the other hand, there is a great degree of freedom in the selection of stacked materials, and various devices with richer performance can be constructed. Therefore, the van der Waals heterojunction shows great application potential in many fields such as logic devices, optical detection devices, photovoltaic devices, etc.

[0033] ​However, the current II WSM and two-dimensional semiconductor material to build van der Waals heterojunction has been reported, the photoelectric detection performance of the device is better than that of pure two-dimensional semiconductor material or semimetal material, such as TaIrTe4 / MoS2 van der Waals heterojunction photodetector, the dark current is effectively suppressed, under 635nm laser irradiation, the dark current is only 0.2pA, the zero bias self-driven response is realized, the responsivity reaches 750mA / W, and the imaging detection function is also realized. Compared with pure WSe2 photodetector, the response cutoff wavelength of TaIrTe4 / WSe2 heterojunction photodetector is extended, and there is obvious response under 808nm laser irradiation, and the responsivity, external quantum efficiency and detectivity are 4.7A / W, 727% and 6x10 11 Jones, and the polarization photodetection function is also realized. WTe2 / MoS2 van der Waals heterojunction photodetector realizes the detection from visible light to near infrared light (400nm-1050nm), which not only reduces the power consumption, but also improves the sensitivity, and can detect weaker infrared light signals. Interestingly, under 1050nm laser irradiation, the device shows abnormal photoelectric response, which is related to the unique energy band structure of semimetal WTe2. Although the device performance of the above-mentioned second type WSM and two-dimensional semiconductor material stacked van der Waals heterojunction photodetector has been improved, the detection cutoff wavelength of the device is still limited to the near infrared band, and the response in the mid-infrared and far-infrared bands is weak or even almost no response, far from the limit of the second type WSM material.

[0034] The inventors believe that the two-dimensional materials in the above reports are TMDs materials, and the carrier mobility of TMDs is relatively low, which may lead to low photoconductivity gain (G). The photoconductivity gain is proportional to the light responsivity (sensitivity), which may be the reason why the TMDs / II WSM heterojunction photodetector has weak or almost no response in the mid-infrared and far-infrared bands. In the family of two-dimensional materials, black phosphorus has a wide spectral response from visible light to mid-infrared (4μm) band; more than 10 3 cm 2 High carrier mobility; high current on-off ratio; excellent light absorption rate and other advantages, the second type of Weyl semimetal and black phosphorus are stacked to form a van der Waals heterojunction, please continue to refer to Figure 1As shown, due to the difference in Fermi level of the two materials, electrons will diffuse from the material with high Fermi level to the material with low Fermi level until the Fermi levels of the two materials reach equilibrium. Due to the diffusion of carriers, a depletion layer will be formed at the interface of the semiconductor and the semimetal material, and an internal electric field is formed in the depletion layer. The photogenerated electron-hole pairs can be effectively separated by the internal electric field, thereby suppressing the dark current and noise; on the other hand, the high carrier mobility of black phosphorus can improve the photoconductivity gain of the device, thereby improving the responsivity (sensitivity) of the device and achieving the ultimate detection range (far-infrared band) of the device; in addition, compared with other two-dimensional materials, the high carrier mobility of BP is also conducive to obtaining a faster response speed of the device. In addition, the BP and II WSM van der Waals heterojunction belongs to the photovoltaic type, which is conducive to realizing a self-driven low-power photodetector, and the BP and II WSM materials both have good light absorption rate, anisotropy and other advantages, therefore, the application creatively constructs the van der Waals heterojunction of BP and II WSM materials to realize high-performance mid-to-far infrared photodetection, achieving the effect of "1+1>2".

[0035] Further, the second aspect of the embodiment of the application also provides a photodetector device, which comprises the photodetection heterojunction, the first electrode and the second electrode provided by any of the above-mentioned embodiments; the first electrode is in electrical contact with the black phosphorus layer in the photodetection heterojunction, and the second electrode is in electrical contact with the second type of Weyl semimetal material layer in the photodetection heterojunction.

[0036] More specifically, in some embodiments, the photodetector device further comprises a substrate, and the photodetection heterojunction, the first electrode and the second electrode are all formed on the surface of the substrate; the black phosphorus layer comprises a first surface and a second surface opposite to each other, the first surface faces the substrate, and the second surface is in direct contact with the second type of Weyl semimetal material layer.

[0037] As for the specific structural features, in some embodiments, the second surface of the black phosphorus layer comprises a first region and a second region, the second type of Weyl semimetal material layer is arranged in the first region, and the second region is an exposed region.

[0038] In addition, as for the specific material selection of other structures, the substrate can include silicon, silicon carbide, sapphire, quartz and the like, and is not limited thereto; the materials of the first electrode and the second electrode can include gold, chromium, nickel, titanium, copper and the like, and are not limited thereto.

[0039] In order to obtain the above-mentioned device, the third aspect of the embodiment of the application also provides a preparation method of a photodetector device, which comprises the following steps:

[0040] An independent black phosphorus layer and a second type of Weyl semimetal material layer are obtained by microexfoliation.

[0041] The black phosphorus layer and the second type Weyl semimetal material layer are stacked in sequence on the substrate surface by dry transfer to form a photoelectric detection heterojunction.

[0042] A first electrode and a second electrode are formed at corresponding positions on the surface of the substrate to obtain a photodetection device.

[0043] In some embodiments, the micro-exfoliation and dry transfer are both performed in a rare gas atmosphere with a purity of 99.999% or higher.

[0044] The technical route of the above technical solution is as follows Figure 2 As shown in the figure: First, BP-II WSM van der Waals heterojunctions were stacked on a substrate by micromechanical lift-off and positioned dry transfer, and the thickness, crystal quality, etc. of the material were characterized; then, BP-II WSM van der Waals heterojunction electrical and photoelectric detection devices were prepared by micro-nanofabrication methods such as photolithography and metal evaporation; secondly, the electrical and photoelectric detection performance of BP-II WSM van der Waals heterojunction devices were studied, and the relationship between parameters such as material type and thickness, contact electrode material, external electric field, and test environment temperature and performance such as carrier mobility, on-off ratio, response range, responsivity, response speed, quantum efficiency, detectivity, signal-to-noise ratio, and dark current was explored.

[0045] As some typical application examples of the above technical solutions, the specific preparation and characterization processes are as follows:

[0046] First, thin films were obtained from BP and II WSM materials (Td-WTe2, Td-MoTe2, Td-TaIrTe4, etc.) by micromechanical exfoliation. Thin film materials with different thicknesses ranging from a few nanometers to tens of nanometers were selected using atomic force microscopy. The BP and II WSM films were then stacked onto the substrate using a positioned dry transfer method to construct a van der Waals heterojunction, such as Figure 3 As shown. In order to ensure the cleanliness between the material surface and the interface, operations such as material stripping and stacking will be carried out in a glove box with a high-purity argon atmosphere (purity 99.999%) to obtain the best device performance. The thickness, crystal structure, elemental composition, surface potential and work function of the material are analyzed by characterization methods such as Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction spectroscopy (XRD), and Kelvin probe force microscopy (KPFM). Then, the device is prepared by micro-nano processing methods such as photolithography and metal evaporation. The electrical properties of the device, such as carrier mobility and switching ratio, are studied. The photoelectric detection performance of the device, such as response range, responsivity, response speed, quantum efficiency, detection rate, signal-to-noise ratio, dark current, etc., are studied.

[0047] Of course, if other various equivalent ways are adopted to prepare the same material, structure and function device, it also belongs to the implementation range of the present application.

[0048] In a typical embodiment, the obtained device has a room temperature carrier mobility greater than 10 3 cm 2 Vs, a switching ratio greater than 10 4 , a detection wavelength cutoff range of 10 μm, and a room temperature responsivity of greater than 1 A / W, a response time faster than 50 μs, and a noise equivalent power of ~ 10 pW / Hz 1 / 2 , and has an imaging detection function.

[0049] Further, based on the above technical solution, the present application also provides the application of the photoelectric detection device provided by any of the above embodiments in far-infrared waveband photoelectric detection.

[0050] The technical solutions of the present application will be further described in detail below through several embodiments combined with the drawings. However, the selected embodiments are only used to illustrate the present application, and do not limit the scope of the present application.

[0051] Embodiment 1

[0052] This embodiment illustrates the preparation and characterization process of a photoelectric detection device, as follows:

[0053] In a high-purity argon atmosphere, thin films of BP and Td-WTe2 materials are obtained by micro-mechanical exfoliation method, and then 10 nanometer thick film materials are selected by atomic force microscope, and the BP and Td-WTe2 material thin films are stacked on a silicon carbide substrate to construct a van der Waals heterojunction by using a positioning dry transfer method.

[0054] Then, the first electrode and the second electrode with gold material are formed by photolithography mask and metal evaporation.

[0055] The thickness, crystal structure, element composition, surface potential and work function of the material are analyzed by Raman spectrometer (Raman), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectrometer (XPS), X-ray diffraction spectrum (XRD), Kelvin probe force microscope (KPFM) and other characterization means.

[0056] The photoelectric detection device obtained in this embodiment has a detection wavelength range of 1-10 μm, and in this wavelength range, the device has a room temperature carrier mobility of the order of 10 3 cm 2 Vs, a switching ratio greater than 10 4 , and a room temperature responsivity of greater than 1 A / W, a response time faster than 50 μs, and a noise equivalent power of ~ 10 pW / Hz1 / 2 .

[0057] Compared with some existing van der Waals heterojunctions, the black phosphorus-second type Weyl semimetal van der Waals heterojunction infrared photodetector provided in the embodiment has the advantage of a wider detection wavelength range. For example, the performance of some existing graphene / WTe2heterojunction devices is obtained under irradiation at a wavelength of about 1550 nm, which belongs to the near-infrared band. The performance of the device provided in the embodiment is measured under mid-infrared (3 μm-10 μm) laser irradiation, and the range of the response wavelength is quite different.

[0058] Embodiment 2

[0059] The embodiment is basically the same as Embodiment 1, and the main difference is that:

[0060] The second type Weyl semimetal material is replaced by MoTe2material, the thickness of the two layers of thin films is adjusted to about 30 nm, the substrate material is replaced by sapphire, and the electrode material is replaced by copper.

[0061] The obtained device still has excellent photoelectric detection performance under mid-infrared. The photoelectric detection device obtained in the embodiment has a detection wavelength range of 1-10 μm, and in this wavelength range, the room-temperature carrier mobility of the device reaches the order of magnitude of 1100 cm 2 Vs, the on-off ratio is greater than 10 5 , the room-temperature responsivity reaches greater than 1 A / W, the response time is faster than 40 μs, and the noise equivalent power is about 8 pW / Hz 1 / 2 .

[0062] Embodiment 3

[0063] The embodiment is basically the same as Embodiment 1, and the main difference is that:

[0064] The second type Weyl semimetal material is replaced by TaRhTe4material, the thickness of the two layers of thin films is adjusted to about 50 nm, the substrate material is replaced by silicon, and the electrode material is replaced by nickel.

[0065] The obtained device still has excellent photoelectric detection performance under mid-infrared. The photoelectric detection device obtained in the embodiment has a detection wavelength range of 1-10 μm, and in this wavelength range, the room-temperature carrier mobility of the device reaches the order of magnitude of 900 cm 2 Vs, the on-off ratio is greater than 10 5 , the room-temperature responsivity reaches greater than 1 A / W, the response time is faster than 50 μs, and the noise equivalent power is about 12 pW / Hz 1 / 2 .

[0066] Embodiment 4

[0067] This embodiment is substantially the same as embodiment 1, with the main differences being:

[0068] The second type of Weyl semimetal material is replaced with NbIrTe4 material, the substrate material is replaced with quartz, and the electrode material is replaced with titanium.

[0069] The photoelectric detection performance of the device obtained in this embodiment is still excellent in the mid-to-far infrared. The photoelectric detection performance of the device obtained in this embodiment is still excellent in the mid-to-far infrared. The detection wavelength range of the photoelectric detection device obtained in this embodiment is 1-10μm. In this wavelength range, the room temperature carrier mobility of the device reaches 1000cm 2 / Vs level, the on / off ratio is greater than 10 6 , and the room temperature response reaches greater than 2A / W, the response time is faster than 50μs, and the noise equivalent power is ~10pW / Hz 1 / 2 .

[0070] Based on the above implementation cases, it can be clearly seen that the present invention stacks BP and the second type WSM material to construct a van der Waals heterojunction. BP has the advantages of room temperature mid-infrared response and fast response, but the detection range is limited to the mid-infrared band; the II WSM material has the advantages of wide-band response and ultrafast response, but the dark current and noise are relatively large. The present invention innovatively selects black phosphorus and the second type WSM to construct the van der Waals heterojunction. On the one hand, the built-in electric field at the interface of the BP and II WSM van der Waals heterojunction is used to separate the photogenerated electron-hole pairs, thereby suppressing the dark current and noise; on the other hand, the high carrier mobility of BP is used to increase the photoconductivity gain of the device, thereby improving the responsivity (sensitivity) of the device and achieving the detection limit of IIWSM (far-infrared band); in addition, BP has a higher carrier mobility, which is also conducive to the device obtaining a faster response speed. Therefore, the construction of the BP-II WSM van der Waals heterojunction can not only give full play to the advantages of each material in mid- and far-infrared detection, but also overcome the shortcomings of the two materials, achieving the effect of "1+1>2", thereby preparing an infrared light detector with excellent performance such as wide-band detection, high responsivity, room temperature response, fast response, self-driven low power consumption, etc., thus overcoming the shortcomings of traditional semiconductor materials and new two-dimensional material infrared photodetectors.

[0071] It should be understood that the above embodiments are merely illustrative of the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent variations or modifications made in accordance with the spirit and substance of the present invention are intended to be encompassed within the scope of protection of the present invention.

Claims

1. A photodetection heterojunction, characterized in that: The invention comprises a van der Waals heterojunction formed by stacking a black phosphorus layer and a second type Weyl semimetal material layer.

2. The photodetection heterojunction according to claim 1, wherein: The second type Weyl semi-metal material layer includes any one or a combination of two or more of WTe2, MoTe2, TaIrTe4, TaRhTe4, TaRuTe4, and NbIrTe4.

3. The photodetection heterojunction according to claim 1, wherein: The thickness of the black phosphorus layer is 5-100 nm; And / or, the thickness of the second-type Weyl semi-metal material layer is 10-100 nm.

4. The photodetection heterojunction according to claim 1, wherein: The response wavelength of the infrared photoelectric detection heterojunction is in the far infrared band.

5. A photoelectric detection device, characterized in that: comprising the photodetection heterojunction according to any one of claims 1 to 4, a first electrode and a second electrode; The first electrode is in electrical contact with the black phosphorus layer in the photodetection heterojunction, and the second electrode is in electrical contact with the second type Weyl semi-metal material layer in the photodetection heterojunction.

6. The photodetection device according to claim 5, wherein: It also includes a substrate, wherein the photodetection heterojunction, the first electrode and the second electrode are all formed on the surface of the substrate; The black phosphorus layer includes a first surface and a second surface facing each other, the first surface faces the substrate, and the second surface is in direct contact with the second-type Weyl semi-metal material layer.

7. The photodetection device according to claim 6, wherein: The second surface of the black phosphorus layer includes a first area and a second area. The second type Weyl semi-metal material layer is applied in the first area, and the second area is an exposed area.

8. A method for preparing a photoelectric detection device, characterized in that: include: An independent black phosphorus layer and a second type Weyl semimetal material layer are obtained by micro-exfoliation; stacking the black phosphorus layer and the second type Weyl semimetal material layer on the substrate surface in sequence by dry transfer to form a photoelectric detection heterojunction; A first electrode and a second electrode are formed at corresponding positions on the surface of the substrate to obtain a photodetection device.

9. The preparation method according to claim 8, characterized in that The micro-stripping and dry transfer are both performed in a rare gas atmosphere with a purity of more than 99.999%.

10. Use of the photoelectric detection device according to any one of claims 5 to 7 in photoelectric detection in the far infrared band.

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