Two-dimensional ferroelectric photovoltaic polarimeter, manufacturing method thereof and polarized light detection method

Abstract

The invention relates to a two-dimensional ferroelectric photovoltaic polarimeter, a manufacturing method thereof and a polarized light detection method. The two-dimensional ferroelectric photovoltaic polarimeter comprises: a substrate; the supporting layer is arranged on the substrate, and steps are formed by the two sides, in the width direction, of the supporting layer and the substrate respectively; the ferroelectric layer comprises a first electrode region, a first strain gradient region, a connecting region, a second strain gradient region and a second electrode region which are sequentially connected in the width direction, the connecting region is stacked on the supporting layer, the first electrode region and the second electrode region are arranged on the substrate, and the ferroelectric layer is made of a two-dimensional material; the first strain gradient region and the second strain gradient region are both used for realizing a bulk photovoltaic effect; an electrode pattern including a first electrode electrically connected to the first electrode region and a second electrode electrically connected to the second electrode region; the first light transmission part is used for transmitting light to the first strain gradient region; and a second light transmission part for transmitting light to the second strain gradient region. The two-dimensional ferroelectric photovoltaic polarimeter can be used for polarized light detection.

Description

Technical Field

[0001] The present application relates to the technical field of photodetectors, in particular to a two-dimensional ferroelectric photovoltaic polarimeter, a manufacturing method thereof, and a polarized light detection method. Background Art

[0002] A photodetector can convert an optical signal into an electrical signal. Photodetectors are widely used in radar guidance, spectral analysis, photographic imaging, and optical communication fields. In recent years, with the rapid development of fields such as artificial intelligence and the Internet of Things, higher requirements have been put forward for the low power consumption and multi-function of photodetectors. The inherent characteristics of the optical field, such as polarization, intensity, and wavelength, provide multi-dimensional optical information for many applications, including but not limited to environmental monitoring, thermal imaging, medical diagnosis, and free space communication. The simultaneous detection of such multi-dimensional optical information provides multiple degrees of freedom for accurately identifying different targets in complex environments and performing multiple forms of tasks in parallel. However, it is difficult to identify the information of light.

[0003] Regarding the polarization characteristics of light, traditional polarimeters need to arrange a series of optoelectronic components in series along the optical path, including lenses, prisms, polarizers, wave plates, filters, photodetectors, and mechanical components, etc. Traditional polarimeters are bulky, with complex technological steps, difficult to miniaturize and integrate, and the extensive use of optical components results in a relatively high cost.

[0004] In a photovoltaic polarization detector, two anisotropic semiconductor materials are required to form a heterojunction so that it can work without an external electric field. Generally, by using the anisotropy of semiconductor materials, the detection of the angle of simple linearly polarized light can be achieved, but to further achieve the detection of multiple polarization states, a complex optical system generally needs to be designed. Although in some technologies, the design of artificial metasurfaces can replace traditional optical systems, its essence is still the superposition of a grating module and a photodetector, and the design of a photovoltaic polarimeter based on artificial metasurfaces will be more complex.

[0005] In addition, a polarization detector requires an additional power meter to decouple the relationship between optical power and polarization angle. Since light with a polarization angle of θ and light with a polarization angle of 180° - θ have the same detection value, the two kinds of light cannot be distinguished. Summary of the Invention

[0006] Based on this, it is necessary to provide a two-dimensional ferroelectric photovoltaic polarimeter, a manufacturing method thereof, and a polarized light detection method for at least one of the above problems.

[0007] In a first aspect, the present application provides a two-dimensional ferroelectric photovoltaic polarimeter, which includes: a substrate; a support layer disposed on the substrate, with steps formed between the two sides of the support layer in the width direction and the substrate respectively; a ferroelectric layer including a first electrode region, a first strain gradient region, a connection region, a second strain gradient region, and a second electrode region connected in sequence in the width direction, the connection region being stacked on the support layer, the first electrode region and the second electrode region being disposed on the substrate, and the material of the ferroelectric layer being a two-dimensional material, such that both the first strain gradient region and the second strain gradient region are used to achieve the bulk photovoltaic effect; an electrode pattern including a first electrode electrically connected to the first electrode region and a second electrode electrically connected to the second electrode region; a first light transmission part for transmitting light to the first strain gradient region; and a second light transmission part for transmitting light to the second strain gradient region.

[0008] By setting the cooperation between the support layer and the substrate, the first strain gradient region and the second strain gradient region are defined in the ferroelectric layer. At the same time, the first light transmission part and the second light transmission part are respectively arranged corresponding to the first strain gradient region and the second strain gradient region, so that light with the same characteristics can be respectively irradiated onto the first strain gradient region and the second strain gradient region, enabling the two-dimensional ferroelectric photovoltaic polarimeter to output different currents for light with the same polarization characteristics when used for detection.

[0009] The two-dimensional ferroelectric photovoltaic polarimeter according to the embodiments of the present application can be used for polarized light detection, achieving accurate measurement of the polarization angle; it can also be used for decoupling the optical power and the polarization angle, realizing multi-functional integration. The two-dimensional ferroelectric photovoltaic polarimeter has a simple structure, can avoid additional optical elements; it can operate without an external electric field power supply; and its size structure is small, reaching the order of hundreds of micrometers.

[0010] In some embodiments, the material of the ferroelectric layer includes binary niobium oxyhalide. Exemplarily, the material of the support layer includes at least one of h-BN, silicon nitride, silicon oxide, and aluminum nitride.

[0011] With such a setting, the anisotropy of the binary niobium oxyhalide is relatively large, and the error of the polarization test of the two-dimensional ferroelectric photovoltaic polarimeter is small. The two-dimensional ferroelectric photovoltaic polarimeter can be used to detect light in the wavelength range of 300 nm to 450 nm. The support layer has insulation; it can ensure the support performance and limit the strain gradient of the ferroelectric layer.

[0012] In some embodiments, the material of the ferroelectric layer is NbOBr2 with the b-axis parallel to the width direction.

[0013] With such a setting, the performance of the two-dimensional ferroelectric photovoltaic polarimeter is good.

[0014] In some embodiments, the thickness range of the ferroelectric layer is from 30 nm to 50 nm. Exemplarily, the thickness range of the support layer is from 80 nm to 200 nm.

[0015] With such a setting, it is easy to manufacture and can also ensure good use performance.

[0016] Exemplarily, the size range of the support layer in the width direction is from 6 μm to 20 μm. Exemplarily, the first optical transmission portion is closer to the support layer relative to the first electrode, and the second optical transmission portion is closer to the support layer relative to the second electrode.

[0017] With such a setting, the first strain gradient region and the second strain gradient region can have a relatively high strain gradient, and light can irradiate at positions with relatively large stress.

[0018] In some embodiments, the first optical transmission portion and the second optical transmission portion are respectively optical waveguides disposed on the substrate, and the two-dimensional ferroelectric photovoltaic polarimeter further includes an upper cladding covering the optical waveguides.

[0019] With such a setting, the manufacturing process of the two-dimensional ferroelectric photovoltaic polarimeter can be compatible with the silicon optical chip process and is easy to integrate.

[0020] In some embodiments, the two-dimensional ferroelectric photovoltaic polarimeter further includes an input optical path, a current acquisition circuit, and a processor. The input optical path is respectively coupled to the first optical transmission portion and the second optical transmission portion. The current acquisition circuit is electrically connected to the electrode pattern, and the processor is electrically connected to the current acquisition circuit. The processor is configured to: calculate the polarization angle of the polarized light according to the response current of the first strain gradient region and the response current of the second strain gradient region, and calculate the optical power.

[0021] With such a setting, the two-dimensional ferroelectric photovoltaic polarimeter can transmit the same light to the first strain gradient region and the second strain gradient region respectively; can accurately obtain the polarization angle and can obtain the optical power.

[0022] In a second aspect, the present application provides a method for manufacturing a two-dimensional ferroelectric photovoltaic polarimeter. The method includes: providing a substrate; forming a first optical transmission portion and a second optical transmission portion; setting a support layer, and forming steps on both sides of the support layer in the width direction with the substrate respectively; disposing a ferroelectric layer on the support layer and the substrate, wherein the ferroelectric layer includes a first electrode region, a first strain gradient region, a connection region, a second strain gradient region, and a second electrode region connected in sequence along the width direction. The connection region is stacked on the support layer, the first electrode region and the second electrode region are disposed on the substrate, the material of the ferroelectric layer is a two-dimensional material, and both the first strain gradient region and the second strain gradient region are used to realize the bulk photovoltaic effect; the first optical transmission portion is used to transmit light to the first strain gradient region, the second optical transmission portion is used to transmit light to the second strain gradient region; and forming an electrode pattern, the electrode pattern includes a first electrode electrically connected to the first electrode region and a second electrode electrically connected to the second electrode region.

[0023] The manufacturing method of the embodiments of the present application can manufacture a two-dimensional ferroelectric photovoltaic polarimeter.

[0024] In a third aspect, the present application provides a method for detecting polarized light. This detection method utilizes the aforementioned two-dimensional ferroelectric photovoltaic polarimeter or the two-dimensional ferroelectric photovoltaic polarimeter obtained by the steps of the aforementioned manufacturing method. The detection method includes: transmitting a first polarized light to a first strain gradient region through a first light transmission part to obtain a first current; transmitting a second polarized light to a second strain gradient region through a second light transmission part to obtain a second current, wherein the polarization characteristics of the second polarized light are the same as those of the first polarized light; and obtaining a polarization angle based on the first current and the second current.

[0025] The detection method according to the embodiments of the present application is easy to implement, can obtain an accurate polarization angle, and can distinguish between the polarization angle θ and the polarization angle 180° - θ.

[0026] In some embodiments, the method for detecting polarized light further includes: obtaining an optical power based on the first current and the second current.

[0027] With such a setting, the detection method can synchronously decouple the optical power, and the steps are simple.

[0028] In some embodiments, the step of obtaining the polarization angle includes: obtaining the polarization angle by using the polarization angle mapping relationship of the two-dimensional ferroelectric photovoltaic polarimeter. Exemplarily, the step of obtaining the polarization angle includes: obtaining the polarization angle by using the polarized light characteristic equation of the two-dimensional ferroelectric photovoltaic polarimeter.

[0029] With such a setting, the polarization angle can be obtained quickly. The method for detecting polarized light can obtain the polarization angle quickly and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of a two-dimensional ferroelectric photovoltaic polarimeter according to one or more embodiments;

[0031] Figure 2 is a schematic top view of a two-dimensional ferroelectric photovoltaic polarimeter according to one or more embodiments;

[0032] Figure 3 is a schematic flowchart of a method for manufacturing a two-dimensional ferroelectric photovoltaic polarimeter according to one or more embodiments;

[0033] Figure 4 is a schematic structural relationship diagram of a two-dimensional ferroelectric photovoltaic polarimeter according to one or more embodiments;

[0034] Figure 5 is a two-dimensional photocurrent curve diagram of a two-dimensional ferroelectric photovoltaic polarimeter according to one or more embodiments;

[0035] Figure 6Schematic flowchart of a method for detecting polarized light according to one or more embodiments.

[0036] Description of reference numerals: 1, substrate; 11, semiconductor layer; 12, insulating layer; 2, support layer; 3, ferroelectric layer; 31, first electrode region; 32, first strain gradient region; 33, connection region; 34, second strain gradient region; 35, second electrode region; 4, electrode pattern; 41, first electrode; 42, second electrode; 50, upper cladding; 51, first light transmission part; 52, second light transmission part;

[0037] 100, two-dimensional ferroelectric photovoltaic polarimeter; 200, input optical path; 300, current acquisition circuit; 400, processor. Detailed implementation manners

[0038] To make the above objects, features, and advantages of the present application more apparent and understandable, the following describes the detailed implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments of the disclosed implementation manners below.

[0039] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "perpendicular", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0040] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0041] In addition, terms such as "first", "second", "third", etc. are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. Exemplarily, the first direction may also be referred to as the second direction, and the second direction may also be referred to as the first direction. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0042] In the present application, unless otherwise clearly defined and limited, terms such as "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a flexible connection or a rigid connection along at least one direction; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, or there may be an intermediate medium while being directly connected, and it may also be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. Terms such as "installed", "set", "fixed", etc. can be understood in a broad sense as a connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0043] The terms "layer" and "region" used in the present application refer to a part of the material that includes a certain area and has a certain thickness. The layer can extend horizontally, vertically, and / or along a conical surface. The layer can be a region of a uniform or non-uniform continuous structure, and its thickness perpendicular to the extension direction may not be greater than the thickness of the continuous structure. The layer can include multiple layers, which can be multiple stacked layers or multiple layers extending discretely. The shapes of various regions and layers in the drawings, as well as their relative sizes and positional relationships, are only exemplary, and may actually deviate due to manufacturing tolerances or technical limitations, and can be adjusted according to actual needs.

[0044] Reference Figure 1 , Figure 1 shows a two-dimensional ferroelectric photovoltaic polarimeter in an embodiment of the present application. In an exemplary embodiment, the two-dimensional ferroelectric photovoltaic polarimeter 100 includes a substrate 1, a support layer 2, a ferroelectric layer 3, an electrode pattern 4, a first light transmission part 51, and a second light transmission part 52.

[0045] For convenience of description, a spatial rectangular coordinate system XYZ is established. The substrate 1 may include a semiconductor layer 11 and an insulating layer 12 stacked along the Z-axis direction. The material of the semiconductor layer 11 may include silicon. The material of the insulating layer 12 may include silicon dioxide. The insulating layer 12 may include an upper layer and a lower layer.

[0046] Exemplarily, the first optical transmission portion 51 and the second optical transmission portion 52 are disposed on the substrate 1. The first optical transmission portion 51 and the second optical transmission portion 52 may be embedded in the upper layer of the insulating layer 12. The two-dimensional ferroelectric photovoltaic polarimeter 100 may further include an upper cladding layer 50. The first optical transmission portion 51 and the second optical transmission portion 52 are configured as optical waveguides. The upper cladding layer 50 helps the optical waveguide to transmit light well.

[0047] The support layer 2 is disposed on the substrate 1 along the Z-axis direction. Exemplarily, it is stacked on the upper cladding layer 50. Refer to Figure 2 , the width direction of the support layer 2 may be parallel to the X-axis direction, the width direction may be referred to as the first direction, and the length direction may be referred to as the second direction. The dimension of the support layer 2 in the width direction may be smaller than the dimension of the support layer 2 in the length direction, and the support layer 2 may be rectangular but not limited thereto. The left and right sides of the support layer 2 may be parallel.

[0048] The material of the support layer 2 may include h-BN, and the two side edges of the support layer 2 in the width direction can resist compression. Optionally, the material of the support layer 2 may include at least one of silicon nitride, silicon oxide, and aluminum nitride. These materials have insulation properties and can be processed into the required patterns by a patterning process. The support layer 2 can ensure the support performance and limit the strain gradient of the ferroelectric layer 3.

[0049] Steps are respectively formed between the two sides of the support layer 2 in the width direction and the substrate 1. The left and right sides of the support layer 2 may be vertical planes along the Z-axis direction, or there may be a certain deviation. When configuring the support layer 2, the first optical transmission portion 51 and the second optical transmission portion 52 can be located on both sides of the support layer 2 along the X-axis direction.

[0050] The ferroelectric layer 3 is disposed on the support layer 2 and the substrate 1. The dimension of the ferroelectric layer 3 in the X-axis direction is larger than the dimension of the support layer 2, and both ends protrude from the support layer 2. The ferroelectric layer 3 includes a first electrode region 31, a first strain gradient region 32, a connection region 33, a second strain gradient region 34, and a second electrode region 35 that are sequentially connected along the width direction of the support layer 2.

[0051] The connection region 33 is stacked on the support layer 2. Both the first electrode region 31 and the second electrode region 35 are lower than the connection region 33. For example, they are disposed on the substrate 1 or the upper cladding layer 50. The sinking of the first electrode region 31 and the second electrode region 35 is due to gravity, and there may also be forced sinking by an external force.

[0052] The electrode pattern 4 includes a first electrode 41 and a second electrode 42. The first electrode 41 is electrically connected to the first electrode region 31. For example, it is stacked on the first electrode region 31 and can press down the first electrode region 31. The second electrode 42 is electrically connected to the second electrode region 35. For example, it is stacked on the second electrode region 35 and can press down the second electrode region 35.

[0053] The material of the ferroelectric layer 3 is a two-dimensional material. The portion of the ferroelectric layer 3 connected between the first electrode region 31 and the connection region 33 becomes the first strain gradient region 32, and the portion of the ferroelectric layer 3 connected between the connection region 33 and the second electrode region 35 becomes the second strain gradient region 34. Both the first strain gradient region 32 and the second strain gradient region 34 are used to achieve the bulk photovoltaic effect. Optionally, the material of the ferroelectric layer 3 includes two-dimensional transition metal chalcogenides or binary niobium oxyhalides, ensuring that both the first strain gradient region 32 and the second strain gradient region 34 are used to achieve the flexoelectric photovoltaic effect.

[0054] Specifically, by setting the support layer 2 to cooperate with the substrate 1, the first strain gradient region 32 and the second strain gradient region 34 are defined in the ferroelectric layer 3. Since the bending directions of the first strain gradient region 32 and the second strain gradient region 34 are different, their strain gradients are also different. When the flexoelectric photovoltaic effect is generated under illumination, photocurrents with opposite directions can be generated.

[0055] The first light transmission part 51 is used to transmit polarized light to the first strain gradient region 32, and can output a first current without an external electric field power supply; while the second light transmission part 52 is used to transmit another portion of polarized light to the second strain gradient region 34. Although this portion of polarized light has the same polarization angle as the previous portion of polarized light, the second current output by the two-dimensional ferroelectric photovoltaic polarimeter 100 is different from the first current.

[0056] By designing two strain gradient regions to receive light respectively, when the two-dimensional ferroelectric photovoltaic polarimeter 100 is used for detection, it can output different currents for light with the same polarization characteristics. The two-dimensional ferroelectric photovoltaic polarimeter 100 according to the embodiment of the present application can be used in polarized light detection and realizes accurate measurement of the polarization angle.

[0057] The two-dimensional ferroelectric photovoltaic polarimeter 100 has a simple structure, does not require additional optical elements to achieve the polarization angle detection function, and does not require a heterojunction to achieve the photovoltaic detection function, greatly realizing the miniaturization and multi-functional integration of the polarimeter. It uses the linear polarization sensitivity of the strain gradient region to achieve polarization detection; it uses the bulk photovoltaic effect to work without an external electric field power supply; and its size structure is small, reaching the micron level.

[0058] Reference Figure 3 This application provides a method 1000 for manufacturing a two-dimensional ferroelectric photovoltaic polarimeter, which may include steps S101 to S105.

[0059] Step S101, providing a substrate 1. The substrate 1 in this step can be a prefabricated substrate. The structure obtained in each step can be the prefabricated structure for the subsequent step. The thickness of the substrate 1 can be 300 nm. In the substrate 1, a silicon dioxide layer is formed on the silicon layer.

[0060] Step S102: Form a first optical transmission part 51 and a second optical transmission part 52.

[0061] Exemplarily, this method can be used to manufacture a two-dimensional ferroelectric photovoltaic polarimeter 100 as Figure 1 shown. Specifically, an optical transmission part can be formed on a substrate 1. The substrate 1 can be 3 μm thick. Step S102 can include: depositing 200 nm of silicon nitride by plasma-enhanced chemical vapor deposition; then spin-coating a photoresist on the surface of the silicon nitride film, patterning the required waveguide pattern using electron beam lithography technology, and etching the silicon nitride layer using a reactive ion etching system after development to achieve pattern transfer, so as to obtain the first optical transmission part 51 and the second optical transmission part 52 made of silicon nitride material; then depositing 200 nm of silicon oxide by plasma-enhanced chemical vapor deposition to fill the surface and obtain an insulating layer 12; after removing the photoresist on the surface of the silicon nitride layer, depositing a 1-μm-thick silicon oxide on the substrate 1 and the silicon nitride layer as an upper cladding 50. The upper cladding 50 covers at least the silicon nitride layer as a waveguide upper cladding.

[0062] The insulating layer 12 can be composed of a silicon oxide layer of a prefabricated substrate and the deposited silicon oxide. In other embodiments, it can also be only based on the prefabricated substrate; or it is formed on the semiconductor layer 11 during the manufacturing process.

[0063] In some other embodiments, step S102 may not be executed first, but step S103 may be executed.

[0064] Step S103: Set a support layer 2. A rectangular h-BN nanosheet can be set on the substrate 1 through a dry transfer process. Exemplarily, it is between the upper cladding 50, the first optical transmission part 51 and the second optical transmission part 52. Stepped portions are respectively formed between the two sides of the support layer 2 in the width direction and the substrate 1. Exemplarily, a stepped portion is formed with the upper cladding 50.

[0065] Step S104: Set a ferroelectric layer 3 on the support layer 2 and the substrate 1. The NbOBr2 nanosheet can be set on the h-BN nanosheet by using a dry transfer process. The h-BN nanosheet has a certain height, and its two edges apply stress to the NbOBr2 nanosheet, forming two high-stress regions, namely a first strain gradient region 32 and a second strain gradient region 34. These two regions respectively correspond to the first optical transmission part 51 and the second optical transmission part 52, and are used to receive the transmitted light to achieve the bulk photovoltaic effect, serving as two measurement regions of the two-dimensional ferroelectric photovoltaic polarimeter 100. Under the action of the support layer 2, the ferroelectric layer 3 can be divided into five regions connected in sequence in the width direction. The connection region 33 is stacked on the support layer 2, and the first electrode region 31 and the second electrode region 35 can be set on the substrate 1.

[0066] Step S105: Form an electrode pattern 4. Specifically, the first electrode 41 and the second electrode 42 can be formed synchronously. First, a 10-nm-thick titanium (Ti) layer can be deposited, and then a 40-nm-thick gold (Au) layer can be deposited. The composite metal layer can have an ohmic contact with the ferroelectric layer 3, having good electrical conductivity to output a current signal, and also having good structural strength and a long service life.

[0067] The manufacturing method according to the embodiments of the present application can manufacture the two-dimensional ferroelectric photovoltaic polarimeter 100. The method 1000 for manufacturing the two-dimensional ferroelectric photovoltaic polarimeter can be compatible with the silicon optical chip process, is easy to integrate, and is easy to implement.

[0068] Combined Figure 4 as shown Figure 4 The two-dimensional ferroelectric photovoltaic polarimeter in the embodiments of the present application is shown. The two-dimensional ferroelectric photovoltaic polarimeter 100 can be manufactured based on the foregoing method, wherein step S102 is executed after step S104.

[0069] In the two-dimensional ferroelectric photovoltaic polarimeter 100 of some embodiments, the support layer 2 is disposed on the substrate 1; the first light transmission part 51 and the second light transmission part 52 can be optical fibers respectively, and are used to transmit light to the first strain gradient region 32 and the second strain gradient region 34 respectively.

[0070] The first light transmission part 51 can be closer to the support layer 2 relative to the first electrode 41, and the second light transmission part 52 can be closer to the support layer 2 relative to the second electrode 42. In the ferroelectric layer 3, the stress of the part close to the edge of the support layer 2 is greater, and light can irradiate at a position with a higher strain gradient, which is beneficial to detection.

[0071] The first light transmission part 51 and the second light transmission part 52 can be symmetrically disposed relative to the support layer 2, or can deviate from each other.

[0072] The thickness range of the support layer 2 is from 80 nm to 200 nm, such as 100 nm, 150 nm, 180 nm. The support layer 2 provides sufficient height for the bending of the ferroelectric layer 3 and can ensure the support effect. Exemplarily, the size range of the support layer 2 in the width direction is from 6 μm to 20 μm, such as 8 μm, 10 μm, 12 μm, 14 μm, 16 μm or 18 μm. The distance between the two edges of the support layer 2 affects the distance between the two high-stress regions in the ferroelectric layer 3 and ensures the good formation of each high-stress region.

[0073] The thickness of the ferroelectric layer 3 ranges from 30 nm to 50 nm, for example, 40 nm. This thickness refers to the actual thickness at each location along the two-dimensional material. The two-dimensional material is not too thin, ensuring a strong flexoelectric photovoltaic effect, which is beneficial for measuring current; the two-dimensional material is not too thick, avoiding difficulty in bending and ensuring easy manufacturing. The ferroelectric layer 3 can be supported by the support layer 2 with a width of 6 μm to 20 μm, and higher stress can be formed on both sides. In some cases, the size of the connection region 33 can approach zero; or it can be considered that there is also a certain stress in the connection region 33.

[0074] In some other embodiments, the stress levels on both sides of the ferroelectric layer 3 can be different. The main thing is to ensure that the strain gradients are opposite; along the extension direction of the two-dimensional material, it is generally parallel to the width direction of the support layer 2.

[0075] In some other embodiments, the middle region of the ferroelectric layer 3 is concave downward while the two side regions are warped upward, forming a strain gradient region.

[0076] The material of the ferroelectric layer 3 can be a two-dimensional transition metal oxide. In this way, the two-dimensional ferroelectric photovoltaic polarimeter 100 has a longer working wavelength. Optionally, the material of the ferroelectric layer 3 is MOS2, and the working wavelength range is from 405 nm to 980 nm.

[0077] The material of the ferroelectric layer 3 can include binary niobium oxyhalides. The anisotropy of binary niobium oxyhalides is relatively large, and the error of polarization testing by the two-dimensional ferroelectric photovoltaic polarimeter 100 is relatively small. The two-dimensional ferroelectric photovoltaic polarimeter 100 can be used to detect light in the wavelength range of 300 nm to 450 nm. The material of the ferroelectric layer 3 can be NbOBr2, with a larger anisotropy ratio, and the error of polarization testing will be relatively small. The two-dimensional ferroelectric photovoltaic polarimeter 100 can be used to detect light in the ultraviolet band with a wavelength range of 300 nm to 405 nm. The material of the ferroelectric layer 3 can be NbOBr2 with the b-axis parallel to the width direction, and the performance of the two-dimensional ferroelectric photovoltaic polarimeter 100 is good.

[0078] Reference Figure 4 , in some embodiments, the two-dimensional ferroelectric photovoltaic polarimeter 100 further includes an input optical path 200 and a current acquisition circuit 300. The input optical path 200 is respectively coupled to the first light transmission part 51 and the second light transmission part 52, and can successively transmit the same light to the two light output parts. The current acquisition circuit 300 is electrically connected to the electrode pattern 4, for example, collecting current from the first electrode 41, while the second electrode 42 is grounded.

[0079] The two-dimensional ferroelectric photovoltaic polarimeter 100 may further include a processor 400. The processor 400 is electrically connected to the current acquisition circuit 300. The processor 400 is configured to calculate the polarization angle of the polarized light according to the response current of the first strain gradient region 32 and the response current of the second strain gradient region 34. The processor 400 is further configured to calculate the optical power. The two-dimensional ferroelectric photovoltaic polarimeter 100 can transmit the same light to the first strain gradient region 32 and the second strain gradient region 34 respectively; can accurately obtain the polarization angle; and can obtain the optical power.

[0080] The two-dimensional ferroelectric photovoltaic polarimeter 100 may further include a memory, and the memory may be electrically connected to the processor 400. The memory can store computer programs for the processor 400 to execute, and can also be used to store the measured data and the calculated results.

[0081] Reference Figure 5 , using the two-dimensional ferroelectric photovoltaic polarimeter 100 to measure polarized light with different polarization angles, when the polarized light is incident on the first strain gradient region 32, the light input 1 acquisition current (unit: A) can be obtained, and when the same polarized light is incident on the second strain gradient region 34, the light input 2 acquisition current can be obtained. Exemplarily, Figure 4 In [reference], the first electrode 41 is located on the left side along the X-axis direction, and the second electrode 42 is located on the right side along the X-axis direction. The left side direction can be defined as the positive X-axis direction, and at this time, the 0° deflection angle of the polarized light can be defined as along the left side direction.

[0082] Facing two kinds of polarized light with polarization angles θ and 180° - θ, the two-dimensional ferroelectric photovoltaic polarimeter 100 of the embodiment of the present application will measure two different reference data points. Furthermore, for each reference data point, it corresponds to polarized light with a uniquely confirmed polarization angle, and the polarization angles θ and 180° - θ will not be confused. Figure 5 Only some reference data points are shown in [reference], and fewer or more reference data can be measured.

[0083] Reference Figure 6 , the present application provides a method 2000 for detecting polarized light. The method 2000 for detecting polarized light can use the aforementioned two-dimensional ferroelectric photovoltaic polarimeter 100 or the two-dimensional ferroelectric photovoltaic polarimeter 100 obtained by the steps of the aforementioned manufacturing method.

[0084] The method 2000 for detecting polarized light may include a step S110 of measuring reference data. In some other embodiments, this step S110 can be executed in advance, for example, regarded as a step of the manufacturing method, and the reference data is written into the memory.

[0085] Exemplarily, the method 2000 for detecting polarized light includes steps S201 to S203.

[0086] Step S201: Transmit the first polarized light to the first strain gradient region 32 through the first optical transmission part 51 to obtain a first current.

[0087] Step S202: Transmit the second polarized light to the second strain gradient region 34 through the second optical transmission part 52 to obtain a second current. The polarization characteristic of the second polarized light is the same as that of the first polarized light. Optionally, the first polarized light and the second polarized light have the same characteristics, for example, the front and rear sections of the same polarized light beam. Step S201 and step S202 are not carried out simultaneously, and the order is not limited.

[0088] Step S203: Obtain the polarization angle according to the first current and the second current. Exemplarily, the steps of obtaining the polarization angle include: obtaining the polarization angle by using the polarization angle mapping relationship of the two-dimensional ferroelectric photovoltaic polarimeter 100. Refer to Figure 5 , after the abscissa and ordinate are respectively confirmed, the corresponding polarization angle can be mapped according to the coordinate point. The detection method of the embodiment of the present application is easy to execute, can obtain an accurate polarization angle, and can distinguish the polarization angle θ and the polarization angle 180° - θ.

[0089] Exemplarily, the steps of obtaining the polarization angle may include: obtaining the polarization angle by using the polarized light characteristic equation of the two-dimensional ferroelectric photovoltaic polarimeter 100. The equation may be:

[0090] ;

[0091] ;

[0092] Wherein, is the first current, is the second current, , , , are respectively coefficients based on the two-dimensional ferroelectric photovoltaic polarimeter 100, which can be obtained according to the reference data and are known quantities when using this equation for calculation. By solving the equation, the polarization angle can be obtained; in addition, the optical power of the polarized light can also be obtained by solving the equation. The detection method of the embodiment of the present application can quickly obtain the polarization angle. The method 2000 for detecting polarized light can quickly and accurately obtain the polarization angle.

[0093] Refer to Figure 6 , the method 2000 for detecting polarized light further includes step S204: obtaining the optical power according to the first current and the second current. This detection method can synchronously decouple the optical power, and the steps are simple. The two-dimensional ferroelectric photovoltaic polarimeter 100 can be used to decouple the optical power and the polarization angle, realizing multi-functional integration.

[0094] The technical features of the above-disclosed embodiments can be combined arbitrarily. For the sake of brevity in description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0095] In the above-disclosed embodiments, unless otherwise clearly specified and limited, the execution order of each step is not restricted. For example, they can be executed in parallel or in different orders successively. The sub-steps of each step can also be executed alternately. Various forms of the process can be used, and steps can also be reordered, added, or deleted, as long as the desired results of the technical solution provided in this application can be achieved. This application does not impose any restrictions here.

[0096] The above-disclosed embodiments only represent several implementation manners of this application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent protection scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the patent protection scope required by this application. Therefore, the patent protection scope of this application shall be subject to the appended claims.

Claims

1. A two-dimensional ferroelectric photovoltaic polarimeter, characterized in that, Comprising: A substrate; A support layer disposed on the substrate, with steps formed between the two sides of the support layer along the width direction and the substrate respectively; A ferroelectric layer including a first electrode region, a first strain gradient region, a connection region, a second strain gradient region, and a second electrode region connected in sequence along the width direction. The connection region is stacked on the support layer, the first electrode region and the second electrode region are disposed on the substrate, and the material of the ferroelectric layer is a two-dimensional material, such that both the first strain gradient region and the second strain gradient region are used to achieve the bulk photovoltaic effect; An electrode pattern including a first electrode electrically connected to the first electrode region and a second electrode electrically connected to the second electrode region; A first light transmission portion for transmitting light to the first strain gradient region; And A second light transmission portion for transmitting light to the second strain gradient region.

2. The two-dimensional ferroelectric photovoltaic polarimeter according to claim 1, characterized in that, The material of the ferroelectric layer includes binary niobium oxyhalide; the material of the support layer includes at least one of h-BN, silicon nitride, silicon oxide, and aluminum nitride.

3. The two-dimensional ferroelectric photovoltaic polarimeter according to claim 2, wherein The material of the ferroelectric layer is NbOBr2 with the b-axis parallel to the width direction.

4. The two-dimensional ferroelectric photovoltaic polarimeter according to claim 1, wherein The thickness range of the ferroelectric layer is from 30 nm to 50 nm; the thickness range of the support layer is from 80 nm to 200 nm, and the size range of the support layer along the width direction is from 6 μm to 20 μm; the first light transmission portion is closer to the support layer relative to the first electrode, and the second light transmission portion is closer to the support layer relative to the second electrode.

5. The two-dimensional ferroelectric photovoltaic polarimeter according to claim 1, wherein The first light transmission portion and the second light transmission portion are respectively optical waveguides disposed on the substrate, and the two-dimensional ferroelectric photovoltaic polarimeter further includes an upper cladding covering the optical waveguides.

6. The two-dimensional ferroelectric photovoltaic polarimeter according to any one of claims 1 to 5, characterized in that, It further includes an input optical path, a current acquisition circuit, and a processor. The input optical path is respectively coupled to the first light transmission portion and the second light transmission portion, the current acquisition circuit is electrically connected to the electrode pattern, and the processor is electrically connected to the current acquisition circuit. The processor is configured to: calculate the polarization angle of polarized light based on the response current of the first strain gradient region and the response current of the second strain gradient region, and calculate the optical power.

7. A method for manufacturing a two-dimensional ferroelectric photovoltaic polarimeter, characterized in that, Comprising: Providing a substrate; Forming a first light transmission portion and a second light transmission portion; Setting a support layer, with steps formed between the two sides of the support layer along the width direction and the substrate respectively; Disposing a ferroelectric layer on the support layer and the substrate, wherein the ferroelectric layer includes a first electrode region, a first strain gradient region, a connection region, a second strain gradient region, and a second electrode region connected in sequence along the width direction. The connection region is stacked on the support layer, the first electrode region and the second electrode region are disposed on the substrate, and the material of the ferroelectric layer is a two-dimensional material, such that both the first strain gradient region and the second strain gradient region are used to achieve the bulk photovoltaic effect; the first light transmission portion is used to transmit light to the first strain gradient region, and the second light transmission portion is used to transmit light to the second strain gradient region; and Forming an electrode pattern, the electrode pattern including a first electrode electrically connected to the first electrode region and a second electrode electrically connected to the second electrode region.

8. A method for detecting polarized light, characterized in that, A two-dimensional ferroelectric photovoltaic polarimeter obtained by using the two-dimensional ferroelectric photovoltaic polarimeter according to any one of claims 1 to 6 or the steps of the method according to claim 7, the method comprising: Transmitting a first polarized light to the first strain gradient region through the first light transmission part to obtain a first current; Transmitting a second polarized light to the second strain gradient region through the second light transmission part to obtain a second current, wherein the polarization characteristic of the second polarized light is the same as that of the first polarized light; and Obtaining a polarization angle according to the first current and the second current.

9. The method for detecting polarized light according to claim 8, wherein, Further comprising: Obtaining an optical power according to the first current and the second current.

10. The method for detecting polarized light according to claim 8 or claim 9, characterized in that, The step of obtaining the polarization angle comprises: Obtaining the polarization angle by using the polarization angle mapping relationship of the two-dimensional ferroelectric photovoltaic polarimeter, or obtaining the polarization angle by using the polarized light characteristic equation of the two-dimensional ferroelectric photovoltaic polarimeter.

Images