Absorber and method for producing the same

Abstract

The application discloses an absorber and a preparation method thereof. The absorber comprises a substrate layer, a metal film layer arranged on the substrate layer, nanowires arranged on the metal film layer, and at least one disc layer arranged on the metal film layer and around the circumference of the nanowires. The disc layer comprises metal nanorings and dielectric nanorings, and the metal nanorings and the dielectric nanorings are alternately and sequentially stacked. The absorber of the application can significantly reduce the manufacturing difficulty, has a simpler structure, increases the absorption bandwidth, and improves the light absorption performance by arranging the nanowires on the metal film layer and arranging the disc layer outside the nanowires and using the nanowires to provide a support structure. Furthermore, the deposition of the disc layer with the metal nanorings and the dielectric nanorings alternately and sequentially stacked can change the wave band of the absorption peak, realize the adjustability of a periodic unit, and improve the overall performance of the absorber.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric device manufacturing, and more particularly to an absorber and a preparation method thereof. BACKGROUND

[0002] The existing absorber has a relatively narrow absorption bandwidth. At present, the absorption bandwidth of the absorber is usually expanded by the following three methods:

[0003] The first method is to couple multiple size metal resonators to generate multiple resonances by constructing resonators of different sizes on the same structural unit to achieve wideband absorption. However, integrating multiple resonators in one structural unit greatly increases the size of the structure. In addition, this method cannot achieve ultra-wideband absorption in the full range from visible light to mid-infrared waveband.

[0004] The second method is to stack multiple layers of metal-dielectric-metal resonators in the vertical direction to form a conical structure. However, due to the complex structure of such absorbers, high requirements are placed on their manufacturing technology, and the multi-layer stacking of different size structures increases their period and height, making it difficult to adjust the spectral range.

[0005] The third method is to embed nanoparticles into a dielectric matrix to achieve wideband absorption. However, due to the agglomeration of nanoparticles in harsh environments, even with a protective layer, the nanoparticles will suffer thermal deformation, affecting the performance and structural stability of the absorber. SUMMARY

[0006] An object of the present application is to provide a new technical solution for an absorber and a preparation method thereof, which can at least solve the problems of complex absorber structure, difficult manufacturing, and relatively narrow sound absorption bandwidth in the prior art.

[0007] In a first aspect, the present application provides an absorber, comprising: a substrate layer; a metal thin film layer disposed on the substrate layer; a nanowire disposed on the metal thin film layer; and at least one disc layer disposed on the metal thin film layer and surrounding the nanowire in the circumferential direction, the disc layer comprising metal nanorings and dielectric nanorings, the metal nanorings and the dielectric nanorings being alternately stacked.

[0008] Optionally, the disc layer is a plurality of disc layers, and the plurality of disc layers are stacked and gradually decrease in radial size in a direction away from the metal thin film layer.

[0009] Optionally, the diameters of the metal nanorings and the dielectric nanorings in each disc layer are the same, and the nanowire is located at the center of the disc layer to configure the absorber into a symmetrical structure.

[0010] Optionally, the number of the disc layers is 2-8, the number of the metal nanorings in each of the disc layers is 2-8, and the number of the dielectric nanorings is 1-8.

[0011] Optionally, the thickness of the metal nanorings is 5-200 nm, and the thickness of the dielectric nanorings is 5-500 nm.

[0012] Optionally, the diameter of the metal nanorings is 100-5000 nm, and the diameter of the dielectric nanorings is 100-5000 nm.

[0013] Optionally, the material of the metal nanorings is gold, silver, copper, titanium or tungsten, and the material of the dielectric nanorings is aluminum oxide, silicon dioxide or zinc sulfide.

[0014] Optionally, the absorber further comprises a protective layer arranged on the side of the disc layer away from the substrate layer.

[0015] Optionally, the material of the protective layer is aluminum oxide, hafnium oxide or tungsten, and the thickness of the protective layer is 2-100 nm.

[0016] In the second aspect, the application provides a preparation method of an absorber, which is used for preparing the absorber described in the above embodiments, and the preparation method comprises the following steps:

[0017] S1, arranging a metal thin film layer on a substrate layer;

[0018] S2, depositing a dielectric layer on the metal thin film layer and etching the dielectric layer to obtain a nanowire;

[0019] S3, sequentially arranging a protective layer and a limiting layer on the outer periphery of the nanowire in sequence, and the protective layer is located between the nanowire and the limiting layer;

[0020] S4, etching the side of the limiting layer away from the metal thin film layer and etching the protective layer to form a deposition space between the nanowire and the limiting layer;

[0021] S5, sequentially and alternately depositing a metal nanoring and a dielectric nanoring with a preset thickness in the deposition space to form a disc layer.

[0022] S6, etching the excess limiting layer to form the absorber.

[0023] Optionally, the preparation method further comprises repeating steps S3, S4 and S5 to deposit a plurality of disc layers arranged in layers in the deposition space, and the radial dimension of the plurality of disc layers in the direction away from the metal thin film layer gradually decreases.

[0024] Optionally, the method for preparing the absorber further comprises:

[0025] S7, depositing a protective layer on the disc layer.

[0026] The absorber of the present application, by arranging nanowires on the metal film layer, arranging disc layers outside the nanowires, and providing support structure by the nanowires, can significantly reduce the manufacturing difficulty, make the structure simpler, increase the absorption bandwidth, and improve the light absorption performance. And by depositing the disc layer which is alternately stacked by metal nanorings and dielectric nanorings, the wave band where the absorption peak is located can be changed, the adjustability of a periodic unit is realized, and the overall performance of the absorber is improved.

[0027] Other features of the present application, and their advantages, will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0029] Figure 1 is a cross-sectional view of the absorber of the embodiment of the present application;

[0030] Figure 2 is a top view of the absorber of the embodiment of the present application;

[0031] Figure 3 is a flowchart of the method for preparing the absorber of the embodiment of the present application;

[0032] Figure 4 is another flowchart of the method for preparing the absorber of the embodiment of the present application;

[0033] Figure 5 is another flowchart of the method for preparing the absorber of the embodiment of the present application;

[0034] Figure 6 is an absorption spectrum of the absorber of the embodiment of the present application;

[0035] Figure 7 is another absorption spectrum of the absorber of the embodiment of the present application;

[0036] Figure 8 is another absorption spectrum of the absorber of the embodiment of the present application.

[0037] Reference signs:

[0038] Absorber 100;

[0039] Substrate layer 10;

[0040] metal thin film layer 20;

[0041] nanowire 30; dielectric layer 31;

[0042] disc layer 40; metal nanoring 401; dielectric nanoring 402; first disc 41; second disc 42; third disc 43; fourth disc 44;

[0043] protective layer 50;

[0044] limiting layer 60;

[0045] deposition space 70. DETAILED DESCRIPTION

[0046] Various exemplary embodiments of the present application will now be described in detail with reference to the figures. It should be noted that the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0047] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the application its application or uses.

[0048] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein, but should be considered as part of the specification, where appropriate.

[0049] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0050] It should be noted that like reference numerals and letters refer to like items throughout the several views of the drawings, and that discussion of one item in a drawing does not preclude further discussion of that item in subsequent drawings.

[0051] In the description of the present application, the terms "first", "second", and the like, if any, can expressly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more unless otherwise specified. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", in general, means an "or" relationship between the front and rear associated objects.

[0052] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] The absorber 100 according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0055] like Figure 1 and Figure 2 As shown, the absorber 100 according to an embodiment of the present invention includes a substrate layer 10, a metal thin film layer 20, nanowires 30 and at least one disk layer 40.

[0056] Specifically, a metal thin film layer 20 is disposed on a substrate layer 10, and nanowires 30 are disposed on the metal thin film layer 20. At least one disk layer 40 is disposed on the metal thin film layer 20, and the disk layer 40 is arranged around the circumference of the nanowires 30. The disk layer 40 includes a metal nanoring 401 and a dielectric nanoring 402, which are alternately stacked in sequence.

[0057] In other words, the absorber 100 according to the embodiments of the present invention is an ultra-wideband, metamaterial absorber 100, which can be used in many fields such as chemical sensing, solar energy collection, solar thermal photovoltaic, thermal emitters, and photoelectric detection. This absorber 100 can maintain high light absorption efficiency over a wide wavelength range, and has very important application value in fields such as photovoltaics, photodetectors, solar vapor generation, and mechanical resonance manipulation.

[0058] See Figure 1 and Figure 2The absorber 100 of this embodiment mainly consists of a substrate layer 10, a metal thin film layer 20, nanowires 30, and at least one disk layer 40. The substrate layer 10 can be a metal or dielectric that provides support, such as gold, silver, copper, silicon, alumina, or silicon dioxide. The metal thin film layer 20 can be disposed on the substrate layer 10, and the substrate layer 10 is grown on the substrate layer 10. The metal thin film layer 20 can be made of common metals, such as gold, silver, copper, titanium, or tungsten, and its thickness can be greater than or equal to 100 nm.

[0059] Nanowires 30 can be disposed on the metal thin film layer 20. Nanowires 30 can be made of materials such as silicon, alumina, or silicon dioxide. A dielectric layer 31, such as silicon, alumina, or silicon dioxide, can be deposited on the metal thin film layer 20. Then, the dielectric layer 31 can be etched to obtain nanowires 30 on the metal thin film layer 20. Nanowires 30 can serve as a support structure for the absorber 100, which helps reduce manufacturing difficulty in subsequent fabrication processes, increases the absorption bandwidth of the absorber 100, and improves the light absorption performance of the absorber 100.

[0060] like Figure 1 and Figure 2 As shown, at least one disk layer 40 is disposed on the metal thin film layer 20, and the disk layer 40 is disposed around the circumference of the nanowire 30. The disk layer 40 can surround the nanowire 30, and the nanowire 30 can provide support for the fabrication of the disk layer 40, reducing the manufacturing difficulty. The disk layer 40 is mainly composed of metal nanorings 401 and dielectric nanorings 402, which are alternately stacked. By depositing a disk layer 40 composed of alternately stacked metal nanorings 401 and dielectric nanorings 402, the wavelength of the absorption peak can be changed, achieving the adjustability of a periodic unit, realizing ultra-wideband absorption from visible light to long-wave far-infrared wavelengths, and effectively improving the overall performance of the absorber 100.

[0061] Therefore, in the absorber 100 according to the embodiment of the present invention, nanowires 30 are disposed on the metal thin film layer 20, and a disk layer 40 is disposed outside the nanowires 30. The nanowires 30 provide a support structure, which significantly reduces manufacturing difficulty, simplifies the structure, increases the absorption bandwidth, and improves light absorption performance. Furthermore, by depositing a disk layer 40 composed of alternating layers of metal nanorings 401 and dielectric nanorings 402, the wavelength band of the absorption peak can be changed, achieving adjustability of a periodic unit and improving the overall performance of the absorber 100.

[0062] According to one embodiment of the present invention, there are multiple disk layers 40, which are stacked together, and the radial dimensions of the multiple disk layers 40 gradually decrease in the direction away from the metal thin film layer 20.

[0063] That is, as shown in Figure 1 and Figure 2 The disc layer 40 can be multiple, multiple disc layers 40 can be stacked, and the radial dimension of the multiple disc layers 40 gradually decreases in the direction away from the metal film layer 20. By changing the number, size and distribution of the disc layer 40, etc., the wave band where the absorption peak is located can be changed to achieve the adjustability of a periodic unit. In the application, a plurality of disc layers 40 of different sizes can be provided on an absorber 100, and the number of disc layers 40 and the number of stacked metal nanorings 401 and dielectric nanorings 402 in the disc layer 40 can be specifically set according to actual needs, and the application does not specifically limit this.

[0064] According to an embodiment of the application, the diameters of the metal nanorings 401 and the dielectric nanorings 402 in each disc layer 40 are the same, and the nanowire 30 is located at the center of the disc layer 40 to construct the absorber 100 into a symmetric structure.

[0065] In other words, referring to Figure 1 and Figure 2 The diameters of the metal nanorings 401 and the dielectric nanorings 402 in each disc layer 40 are the same. The nanowire 30 is arranged at the center of the disc layer 40, and each disc layer 40 is arranged annularly around the center line of the nanowire 30 to construct the absorber 100 into a symmetric structure, so that the absorber 100 has the advantage of polarization insensitivity.

[0066] According to an embodiment of the application, the number of disc layers 40 can be 2-8, the number of metal nanorings 401 in each disc layer 40 can be 2-8, and the number of dielectric nanorings 402 can be 1-8. The radial dimension of different disc layers 40 gradually decreases in the direction away from the metal film layer 20. By providing 1-4 disc layers 40 of different sizes, the wave band where the absorption peak is located can be changed to achieve the adjustability of a periodic unit. Ultra-wideband absorption from visible light to long-wave far infrared band is achieved, effectively improving the overall performance of the absorber 100.

[0067] In the application, by providing different numbers of metal nanorings 401 and dielectric nanorings 402 in each disc layer 40, the wave band where the absorption peak is located can be changed to achieve the adjustability of a periodic unit. Ultra-wideband absorption from visible light to long-wave far infrared band is achieved, effectively improving the overall performance of the absorber 100.

[0068] In some embodiments of the present application, the thickness of the metal nanoring 401 can be 5-200 nm, and the thickness of the dielectric nanoring 402 can be 5-500 nm. The diameter of the metal nanoring 401 can be 100-5000 nm, and the diameter of the dielectric nanoring 402 can be 100-5000 nm. The material of the metal nanoring 401 can be gold, silver, copper, titanium, tungsten or the like, and the material of the dielectric nanoring 402 can be aluminum oxide, silicon dioxide or zinc sulfide or the like. By setting appropriate thickness and diameter of the metal nanoring 401 and the dielectric nanoring 402, the wave band where the absorption peak is located can be changed, the adjustability of a periodic unit is realized, and the absorption bandwidth of the absorber 100 is expanded. The materials of the metal nanoring 401 and the dielectric nanoring 402 are abundant and easy to obtain, which is conducive to reducing the manufacturing cost of the absorber 100.

[0069] In some embodiments of the present application, the absorber 100 further comprises a protective layer arranged on the side of the disc layer 40 away from the substrate layer 10. The material of the protective layer can be aluminum oxide, hafnium oxide or tungsten, and the thickness of the protective layer can be 2-100 nm.

[0070] In other words, the absorber 100 further comprises a protective layer arranged on the side of the disc layer 40 away from the substrate layer 10. A layer of protective layer with refractory dielectric is covered on the outer surface of the absorber 100 to protect the absorber 100. The material of the protective layer can be refractory material such as aluminum oxide, hafnium oxide or tungsten, and the thickness of the protective layer can be 2-100 nm. By covering a layer of protective layer with refractory dielectric on the outer surface of the absorber 100, permanent deformation of the device in high temperature environment can be avoided, the chemical stability and thermal stability of the device are improved, the working temperature that the absorber 100 can be applied to is improved, and the application range is wider.

[0071] In summary, according to the absorber 100 of the embodiments of the present application, the nanowire 30 is arranged on the metal thin film layer 20, and the disc layer 40 is arranged outside the nanowire 30. The support structure is provided by the nanowire 30, the manufacturing difficulty is significantly reduced, the structure is simpler, the absorption bandwidth is increased, and the light absorption performance is improved. By depositing the disc layer 40 in which the metal nanoring 401 and the dielectric nanoring 402 are alternately stacked, the wave band where the absorption peak is located can be changed, the adjustability of a periodic unit is realized, and the overall performance of the absorber 100 is improved. The chemical stability and thermal stability of the absorber 100 are good, the working temperature that the absorber 100 can be applied to is improved, and the application range is wider.

[0072] The absorber 100 of the present application will be described below in conjunction with specific embodiments.

[0073] Embodiment one:

[0074] AsFigure 1 and Figure 2 As shown in the figure, the absorber 100 of the ultra-wideband metamaterial of the present application comprises, from bottom to top, a substrate layer 10, a metal film layer 20 and a nanowire 30. The nanowire 30 can be wrapped with a plurality of disc layers 40, which are respectively a first disc 41, a second disc 42, a third disc 43 and a fourth disc 44. The first disc 41 is closely connected with the metal film layer 20. The first disc 41 is composed of metal nanorings 401 and dielectric nanorings 402 of different sizes in multiple layers alternately.

[0075] Specifically, the thickness of the metal film layer 20 is 200 nm, and the length and width are both 3000 nm. The thickness of the metal nanorings 401 on the first disc 41 is 15 nm, and the thickness of the dielectric nanorings 402 is 140 nm. The diameter of the metal nanorings 401 and the dielectric nanorings 402 is both 2900 nm, and the number of the metal nanorings 401 and the dielectric nanorings 402 is both 5. The diameter of the metal nanorings 401 and the dielectric nanorings 402 on the second disc 42 is both 2300 nm, and the number of the metal nanorings 401 and the dielectric nanorings 402 is both 5. The diameter of the metal nanorings 401 and the dielectric nanorings 402 on the third disc 43 is both 1700 nm, and the number of the metal nanorings 401 and the dielectric nanorings 402 is both 5. The diameter of the metal nanorings 401 and the dielectric nanorings 402 on the fourth disc 44 is both 1100 nm, and the number of the metal nanorings 401 and the dielectric nanorings 402 is both 5. The diameter of the nanowire 30 is 500 nm, and the height is 2720 nm.

[0076] The substrate layer 10 is made of silicon, the metal film layer 20 is made of gold, the metal nanorings 401 are made of titanium, the dielectric nanorings 402 are made of zinc sulfide, and the nanowire 30 is made of silicon.

[0077] The absorption performance of the absorber 100 of the ultra-wideband metamaterial of the present application is shown in the figure. Figure 6 The structure can realize impedance matching with the incident electromagnetic wave, so that the energy can enter the absorber 100 well. The electromagnetic wave is gradually dissipated through the Fabry-Perot resonance and slow light effect generated by the internal resonant cavity. The absorber 100 can realize an absorption wavelength range of 400 nm to 17 μm, and the average absorption efficiency is 98.8%.

[0078] Example Two:

[0079] The difference from Example One is that the number of the metal nanorings 401 on each disc layer 40 in the absorber 100 is 2, and the number of the dielectric nanorings 402 is 1.

[0080] The absorption performance of the ultra-wideband metamaterial absorber 100 of the present application is shown in Figure 7 When the number of metal nanorings 401 and dielectric nanorings 402 decreases, the length of the resonant cavity inside the corresponding nanorings decreases, and the energy cannot be fully consumed by oscillation inside the resonant cavity, resulting in a decrease in absorption efficiency. Through simulation calculation, the ultra-wideband metamaterial absorber 100 can achieve an average absorption efficiency of 89.9% in the absorption wavelength range of 400 nm to 17 μm.

[0081] Example Three

[0082] The difference from Example One is that the number of metal nanorings 401 and dielectric nanorings 402 on each disc in the absorber 100 is 6.

[0083] The absorption performance of the absorber 100 is shown in Figure 8 When the number of metal nanorings 401 and dielectric nanorings 402 increases, the impedance of the absorber 100 changes, resulting in poor impedance matching between the incident electromagnetic wave and the structure, and the electromagnetic wave cannot completely enter the structure, causing the absorption efficiency to gradually decrease. Through simulation calculation, the ultra-wideband metamaterial absorber 100 can achieve an average absorption efficiency of 98.4% in the absorption wavelength range of 400 nm to 17 μm.

[0084] Example Four

[0085] The difference from Example One is that after the absorber 100 is manufactured, a layer of 5 nm aluminum oxide is deposited on the surface as a protective layer by atomic layer deposition technology. Aluminum oxide can protect the thermal stability of the device at high temperature, avoid oxidation of the device surface, and improve the chemical stability of the device. In addition, the addition of aluminum oxide has no effect on the absorption efficiency.

[0086] Through simulation calculation, the ultra-wideband metamaterial absorber 100 can achieve an average absorption efficiency of 98.9% in the absorption wavelength range of 400 nm to 17 μm.

[0087] Example Five

[0088] The difference from Example One is that the number of metal nanorings 401 and dielectric nanorings 402 on each disc in the absorber 100 is 8. When the number of metal nanorings 401 and dielectric nanorings 402 increases, the impedance of the absorber 100 changes, resulting in poor impedance matching between the incident electromagnetic wave and the structure, and the electromagnetic wave cannot completely enter the structure, causing the absorption efficiency to gradually decrease. The absorption efficiency of the absorber 100 can reach about 98%.

[0089] Example Six

[0090] The difference from the embodiment one is that the absorber 100 is provided with two disc layers 40, and the number of the metal nanorings 401 and the dielectric nanorings 402 in each disc layer 40 is 2. When the number of the disc layers 40 and the number of the metal nanorings 401 and the dielectric nanorings 402 in the disc layer 40 are appropriately reduced, the absorber 100 can also maintain an absorption efficiency of about 98%.

[0091] Embodiment seven

[0092] The difference from the embodiment one is that the number of the disc layers 40 is 8. When the number of the disc layers 40 is increased, the impedance of the absorber 100 changes, resulting in that the incident electromagnetic wave cannot be well impedance-matched with the structure, the electromagnetic wave cannot completely enter the inside of the structure, and the absorption efficiency gradually decreases. The absorption efficiency of the absorber 100 can reach about 98%.

[0093] Test method: The absorption efficiency curves of the above embodiments 1-7 are obtained by testing the transmission and reflection spectrum of the device (the absorber 100). Since the test spectrum band is wide, different optical test systems can be used in different bands. After testing, the measured spectrum is spliced to obtain the spectral diagram of the entire band of the device. In the 0.2-2.5um band range, a spectrophotometer coupled with an integrating sphere is used for testing. In the 2.5-20um band range, a spectrometer is used for testing.

[0094] According to a second aspect of the present application, a preparation method of an absorber 100 is provided for preparing the absorber 100 in the above embodiments, as shown in the figure, the preparation method comprises: Figures 3 to 5 S1, a metal film layer 20 is arranged on a substrate layer 10;

[0095] S2, a dielectric layer 31 is deposited on the metal film layer 20, and the dielectric layer 31 is etched to obtain a nanowire 30;

[0096] S3, a protective layer 50 and a limiting layer 60 are sequentially arranged on the outer periphery of the nanowire 30 in sequence, and the protective layer 50 is located between the nanowire 30 and the limiting layer 60;

[0097] S4, the side of the limiting layer 60 away from the metal film layer 20 is etched, and the protective layer 50 is etched to form a deposition space 70 between the nanowire 30 and the limiting layer 60;

[0098] S5, metal nanorings 401 and dielectric nanorings 402 with a predetermined thickness are alternately deposited in the deposition space 70 to form a disc layer 40.

[0099] S5, metal nanorings 401 and dielectric nanorings 402 with a predetermined thickness are alternately deposited in the deposition space 70 to form a disc layer 40.

[0100] S6, etching the excess limiting layer 60 to form the absorber 100.

[0101] In other words, referring to Figures 3 to 5 In the preparation method of the absorber 100 in the embodiment of the present application, first, the metal thin film layer 20 can be grown on the substrate layer 10. Then, the dielectric layer 31 is deposited on the metal thin film layer 20, and the dielectric layer 31 is etched to obtain the nanowire 30 or nanowire array (see Figure 3 Then, as shown in Figure 3 and Figure 4 , the protective layer 50 and the limiting layer 60 can be sequentially grown outside the nanowire 30, the protective layer 50 can be a silicon dioxide layer, and the limiting layer 60 can be a polycarbonate layer. The protective layer 50 is located between the nanowire 30 and the limiting layer 60. Then, the side of the limiting layer 60 away from the metal thin film layer 20 is etched, the polycarbonate layer on the top of the silicon dioxide layer is removed, and the protective layer 50 is etched to facilitate the formation of the deposition space 70 between the nanowire 30 and the limiting layer 60. Then, the metal nanorings 401 and the dielectric nanorings 402 of a predetermined thickness can be alternately deposited in the deposition space 70 to prepare the disc layer 40. Finally, the excess limiting layer 60 and the residual material on the top of the nanowire 30 are etched to form the absorber 100.

[0102] In the present application, multiple disc layers 40 can be deposited according to actual needs, referring to Figure 5 During the deposition of each disc layer 40, steps S3, S4, and S5 can be repeated. By changing the materials, sizes, distribution conditions, and number of the metal nanorings 401 and the dielectric nanorings 402, the waveband of the absorption peak can be changed to achieve the adjustability of a periodic unit.

[0103] The preparation method of the absorber 100 of the present application is easier to manufacture than the prior art, has a longer light absorption bandwidth, and has better light absorption performance. In addition, by depositing different numbers of metal nanorings 401 and dielectric nanorings 402, the absorption wavelength and the manufacturing difficulty can be changed to improve the practical application potential of the device.

[0104] According to an embodiment of the present application, the preparation method of the absorber 100 further comprises:

[0105] Steps S3, S4, and S5 are repeated, and multiple disc layers 40 can be deposited in the deposition space 70, and the radial size of the multiple disc layers 40 gradually decreases in the direction away from the metal thin film layer 20. The present application can deposit multiple disc layers 40 according to actual needs, referring to Figure 5During the deposition of each disc layer 40, steps S3, S4 and S5 can be repeated. By changing the materials, sizes, distribution conditions and numbers of the metal nanorings 401 and the dielectric nanorings 402, the wave band of the absorption peak can be changed, and the adjustability of a periodic unit can be realized.

[0106] Optionally, the number of the metal nanorings 401 in each deposited disc layer 40 is 2-6, and the number of the dielectric nanorings 402 is 1-6, and the metal nanorings 401 and the dielectric nanorings 402 in each disc layer 40 are alternately and sequentially stacked. The number of the disc layers 40 can be 1-4, and the radial sizes of the different disc layers 40 gradually decrease in the direction away from the metal film layer 20. The number of the metal nanorings 401 in each disc layer 40 can be 2-6, and the number of the dielectric nanorings 402 can be 1-6, and the metal nanorings 401 and the dielectric nanorings 402 in each disc layer 40 are alternately and sequentially stacked. By setting 1-4 disc layers 40 with different sizes, and setting different numbers of the metal nanorings 401 and the dielectric nanorings 402 in each disc layer 40, the wave band of the absorption peak can be changed, and the adjustability of a periodic unit can be realized. The super-wideband absorption from visible light to long-wave far infrared can be realized, and the overall performance of the absorber 100 can be effectively improved.

[0107] According to an embodiment of the present application, the preparation method of the absorber 100 further comprises:

[0108] S7, depositing a protective layer on the disc layer 40.

[0109] That is, after etching the residual material on the top of the nanowire 30 and the excess limiting layer 60, a refractory dielectric protective layer is arranged on the outer surface of the disc layer 40 or the outer surface of the overall structure of the absorber 100, so as to protect the absorber 100, avoid permanent deformation of the device in a high-temperature environment, improve the chemical stability and thermal stability of the device, improve the working temperature of the absorber 100, and have a wider application range.

[0110] The preparation method of the absorber 100 of the present application will be described below in combination with specific embodiments.

[0111] Referring to Figures 3 to 5 , the steps of Embodiment One mainly include:

[0112] 1. A silicon wafer is selected as the substrate layer 10, and the metal film layer 20 is grown on the substrate layer 10. Specifically, an electron beam evaporation or a magnetron sputtering method can be used. A 5 μm-thick silicon layer is deposited on the metal film layer 20. Specifically, an electron beam evaporation or a magnetron sputtering method can be used.

[0113] 2. The ordered silicon nanowire array can be prepared by using a template method, and can be formed by using a polystyrene ball template, an aluminum oxide template, a silicon dioxide template, a photoresist template or the like. The diameter of the obtained silicon nanowire is 500 nm.

[0114] 3. A 2.9-micron-thick silicon dioxide layer (a protective layer 50) is grown outside the nanowire 30 through a sol-gel process, and then a polycarbonate layer (a limiting layer 60) is grown outside the silicon dioxide layer through spin coating.

[0115] 4. The surface excess polycarbonate is removed by using an oxygen plasma etching machine, and the silicon dioxide layer is exposed. A wet etching process is used to drop hydrofluoric acid solution on the surface of the sample to remove the silicon dioxide layer.

[0116] 5. A 15-nm-thick titanium layer (a metal nanoring 401) and a 140-nm-thick zinc sulfide layer (a dielectric nanoring 402) are alternately deposited in sequence through electron beam evaporation or magnetron sputtering. The number of layers of the titanium layer and the zinc sulfide layer can each be 2 layers.

[0117] 6. Step 3 is repeated, the surface excess polycarbonate is removed by using an oxygen plasma etching machine, and the silicon dioxide layer is exposed. A dry etching process is used to remove the silicon dioxide layer by using hydrofluoric acid gas.

[0118] 7. Step 5 is repeated, and the excess polycarbonate and the structure on the top of the silicon nanowire 6 are removed by using an oxygen plasma etching machine and metal-assisted chemical etching.

[0119] 8. A 5-nm-thick aluminum oxide protective layer is covered by using atomic layer deposition, and finally the absorber 100 of the present application is obtained.

[0120] The preparation method of the absorber 100 according to the embodiment of the present application is simple and has low difficulty, can effectively increase the absorption bandwidth, improve the light absorption performance and has good stability. And by depositing the disc layer 40 in which the metal nanoring 401 and the dielectric nanoring 402 are alternately stacked in sequence, the wave band where the absorption peak is located can be changed, the adjustability of a periodic unit is realized, and the overall performance of the absorber 100 is improved.

[0121] Of course, the specific working principle of the absorber 100 can be understood and realized by those skilled in the art, and will not be described in detail in the present application.

[0122] While certain specific embodiments of the application have been described in detail herein for the purposes of exemplification and to provide a thorough and enabling disclosure, it will be understood that the application is not limited to the particular embodiments described. Any modifications of the methods and materials described herein, which come within the scope and spirit of the application, are to be considered within the scope of the application. The scope of the application is to be determined by the claims appended hereto, which are to be construed in accordance with the principles of patent law.

Claims

1. An absorber, characterized in that, include: basal layer; A metal thin film layer, wherein the metal thin film layer is disposed on the substrate layer; Nanowires, wherein the nanowires are disposed on the metal thin film layer; At least one disk layer is disposed on the metal thin film layer and the disk layer is arranged around the circumference of the nanowire, with the top of the nanowire exposed in the disk layer; the disk layer includes at least one metal nanoring and at least one dielectric nanoring, and the at least one metal nanoring and the at least one dielectric nanoring are alternately stacked in sequence.

2. The absorber according to claim 1, characterized in that, There are multiple disk layers, which are stacked on top of each other, and the radial dimensions of the multiple disk layers gradually decrease in the direction away from the metal film layer.

3. The absorber according to claim 1, characterized in that, The metal nanorings and dielectric nanorings within each of the disk layers have the same diameter, and the nanowires are located at the center of the disk layers to construct the absorber into a symmetrical structure.

4. The absorber according to claim 1, characterized in that, The number of disk layers is 2-8, and the number of metal nanorings in each disk layer is 2-8, and the number of dielectric nanorings is 1-8.

5. The absorber according to claim 1, characterized in that, The thickness of the metal nanoring is 5-200 nm, the thickness of the dielectric nanoring is 5-500 nm, the diameter of the metal nanoring is 100-5000 nm, and the diameter of the dielectric nanoring is 100-5000 nm.

6. The absorber according to claim 1, characterized in that, The metal nanorings are made of gold, silver, copper, titanium or tungsten, and the dielectric nanorings are made of alumina, silicon dioxide or zinc sulfide.

7. The absorber according to claim 1, characterized in that, Also includes: A protective layer is disposed on the side of the disk layer opposite to the base layer.

8. The absorber according to claim 7, characterized in that, The protective layer is made of aluminum oxide, hafnium oxide, or tungsten, and its thickness is 2-100 nm.

9. A method for preparing an absorber, used to prepare an absorber as described in any one of claims 1-8, characterized in that, The preparation method includes: S1. A metal thin film layer is formed on the substrate layer; S2. Deposit a dielectric layer on the metal thin film layer and etch the dielectric layer to obtain nanowires; S3. A protective layer and a limiting layer are sequentially disposed on the outer periphery of the nanowire, wherein the protective layer is located between the nanowire and the limiting layer. S4. Etch the side of the limiting layer away from the metal thin film layer, and etch the protective layer to form a deposition space between the nanowire and the limiting layer; S5. Metal nanorings and dielectric nanorings of a predetermined thickness are sequentially and alternately deposited in the deposition space to form a disk layer. S6. Etch away the excess limiting layer to form the absorber.

10. The method for preparing the absorber according to claim 9, characterized in that, Also includes: Repeat steps S3, S4 and S5 to deposit multiple stacked disk layers in the deposition space, wherein the radial dimension of the multiple disk layers gradually decreases in the direction away from the metal thin film layer.

11. The method for preparing the absorber according to claim 9, characterized in that, Also includes: S7. Deposit a protective layer on the disk layer.

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