阅读说明：本技术 一种软x射线滤光片及其制备方法和用途 (Soft X-ray optical filter and preparation method and application thereof ) 是由 孟建伟 翁祖谦 于 2021-08-24 设计创作，主要内容包括：本发明涉及X射线探测应用领域,特别是涉及一种软X射线滤光片及其制备方法和用途。本发明所提供的软X射线滤光片,包括石墨烯支撑层,所述石墨烯支撑层表面涂覆有铝膜。本申请所提供的软X射线滤光片采用了石墨烯作为铝膜的支撑结构,使得能量在277eV附近的光子,其透过率可达到90％以上,克服了现有滤光片对该能量范围透过率底的问题,而对于能量范围在400-1000eV的光子,其最低透过率更是达到95％以上,尤其是能量大于1000eV的光子,几乎完全透过。(The invention relates to the field of X-ray detection application, in particular to a soft X-ray filter and a preparation method and application thereof. The soft X-ray filter provided by the invention comprises a graphene supporting layer, wherein an aluminum film is coated on the surface of the graphene supporting layer. The soft X-ray filter provided by the application adopts the graphene as a supporting structure of the aluminum film, so that the transmittance of photons with the energy near 277eV can reach more than 90%, the problem of low transmittance of the existing filter in the energy range is solved, and the lowest transmittance of the photons with the energy range of 400-plus-1000 eV is more than 95%, particularly, the photons with the energy more than 1000eV are almost completely transmitted.)

1. The soft X-ray filter comprises a graphene supporting layer, wherein an aluminum film is coated on the surface of the graphene supporting layer.

2. The soft X-ray filter according to claim 1, wherein the graphene support layer has a thickness of 0.35 to 0.7 nm.

3. The soft X-ray filter according to claim 1, wherein the aluminum film has a thickness of 10 to 50 nm.

4. The soft X-ray filter according to claim 1, wherein the soft X-ray filter further comprises a frame structure, the graphene support layer being secured to the frame structure.

5. The soft X-ray filter according to claim 1, wherein the soft X-ray filter has a transmittance of 80% or more for photons having an energy of 200 to 1000 eV;

and/or the soft X-ray filter has a passing rate of more than or equal to 95% for photons with energy of 400-1000 eV.

6. The method for producing a soft X-ray filter according to any one of claims 1 to 5, comprising: and forming an aluminum film on the surface of the graphene support layer.

7. The method according to claim 6, wherein the method for forming the aluminum film on the surface of the graphene support layer is selected from a physical vapor deposition method.

8. The method of claim 7, wherein the physical vapor deposition process is selected from the group consisting of electron beam evaporation.

9. The method of claim 6, further comprising: and fixing the graphene support layer on the frame structure.

10. The method of claim 9, wherein the frame structure is made of silicon.

Technical Field

The invention relates to the field of X-ray detection application, in particular to a soft X-ray filter and a preparation method and application thereof.

Background

In X-ray detection applications, it is generally desirable to filter light of a certain wavelength band or to allow X-rays of a certain wavelength band to pass through. For example, in the soft X-ray band, a filter is generally installed in front of the detector to allow only photons in an energy range of 100 to 1000eV to pass through, thereby shielding the influence of visible light on the detection result. The traditional optical filter uses a polymer film of paraxylene as a supporting structure, and then a layer of metal aluminum film is plated on the film, thereby realizing the functions of filtering visible light and transmitting soft X-rays. However, the polymer of p-xylene has a strong absorption effect near 277-400 eV of energy, so that the transmittance in the energy range is very low, and the measurement result of the detector is influenced. For example, when we need to perform a spectroscopic analysis of carbon in a sample, we cannot measure a useful sample signal because the characteristic line energy of carbon is around 277eV, which is just absorbed by the p-xylene polymer. In addition, the thickness of the p-xylene polymer is generally in the micrometer range, and the thick film has obvious blocking effect on soft X-rays, and even photons with the energy of 400eV (energy which is frequently detected in the nitrogen fixing reaction process), the transmittance is only 10%. It can thus be seen that the disadvantages of conventional soft X-ray filters severely limit the detection and application of the detector in the soft X-ray band.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a soft X-ray filter, a method of manufacturing the same, and a use thereof, which solve the problems of the prior art.

To achieve the above and other related objects, an aspect of the present invention provides a soft X-ray filter including a graphene support layer having an aluminum film coated on a surface thereof.

In some embodiments of the invention, the thickness of the graphene support layer is 0.35-0.7 nm.

In some embodiments of the present invention, the thickness of the aluminum film is 10 to 50 nm.

In some embodiments of the present invention, the soft X-ray filter further comprises a frame structure, and the graphene support layer is fixed on the frame structure.

In some embodiments of the invention, the soft X-ray filter has a transmittance of more than or equal to 80% for photons with energy of 200-1000 eV;

and/or the soft X-ray filter has a passing rate of more than or equal to 95% for photons with energy of 400-1000 eV.

Another aspect of the present invention provides a method for preparing the soft X-ray filter, including: and forming an aluminum film on the surface of the graphene support layer.

In some embodiments of the present invention, the method for forming an aluminum film on the surface of the graphene support layer is selected from a physical vapor deposition method.

In some embodiments of the invention, the physical vapor deposition process is selected from electron beam evaporation.

In some embodiments of the invention, further comprising: and fixing the graphene support layer on the frame structure.

In some embodiments of the present invention, the frame structure is made of silicon.

Drawings

FIG. 1 is a schematic diagram of a process for manufacturing a soft X-ray filter in example 1 of the present invention.

Fig. 2 is a schematic view of graphene transferred to the surface of an open-pore silicon wafer in example 1 of the present invention.

Fig. 3 is a schematic view of a graphene surface with an aluminum film deposited thereon in embodiment 1 of the present invention.

FIG. 4 is a schematic diagram showing comparison of measured signals of CCD before and after adding the filter in example 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, and other advantages and effects of the present invention will be apparent to those skilled in the art from the disclosure of the present specification.

For the sake of brevity, only some numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form a range not explicitly recited, and any lower limit may be combined with other lower limits to form a range not explicitly recited, as well as any upper limit may be combined with any other upper limit to form a range not explicitly recited. Also, although not explicitly recited, each point or individual value between endpoints of a range is encompassed within the range. Thus, each point or individual value can form a range not explicitly recited as its own lower or upper limit in combination with any other point or individual value or in combination with other lower or upper limits.

In the description herein, it is to be noted that, unless otherwise specified, "above" and "below" are inclusive, and "one or more" of "plural" means two or more.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies illustrative embodiments. At various points throughout this application, guidance is provided through a series of embodiments that can be used in various combinations. In various embodiments, the list is merely a representative group and should not be construed as exhaustive.

The invention provides a soft X-ray filter which comprises a graphene supporting layer, wherein an aluminum film is coated on the surface of the graphene supporting layer. The soft X-ray filter is based on a graphene support structure, an aluminum film in the soft X-ray filter can basically and completely block visible light from transmitting, the filter has higher transmittance for photons in a specific energy range on the whole, and the transmittance of the soft X-ray can be well ensured.

In the soft X-ray filter that this application provided, the supporting layer of graphite alkene mainly is as the bearing structure in the soft X-ray filter, and it has fine toughness and light transmissivity, can be used for as the carrier, adopts graphite alkene as the bearing structure of aluminium membrane, can effectively improve the transmissivity of photon. The graphene support layer generally needs to have a suitable thickness, for example, the thickness of the graphene support layer may be 0.35-0.7 nm, 0.35-0.4 nm, 0.4-0.45 nm, 0.45-0.5 nm, 0.5-0.55 nm, 0.55-0.6 nm, 0.6-0.65 nm, or 0.65-0.7 nm.

In the soft X-ray filter provided by the application, the aluminum film is mainly used as a component for blocking visible light in the soft X-ray filter, the aluminum film can be used for basically and completely blocking the visible light, and meanwhile, the transmittance of soft X-rays is ensured. The aluminum film generally needs to have a suitable thickness, for example, the thickness of the aluminum film may be 10 to 50nm, 10 to 15nm, 15 to 20nm, 20 to 25nm, 25 to 30nm, 30 to 35nm, 35 to 40nm, 40 to 45nm, or 45 to 50 nm.

The soft X-ray filter provided by the application can further comprise a frame structure. The shape of the frame structure is not particularly limited, and is mainly suitable for supporting and unfolding a soft X-ray filter, and allowing light to be filtered (e.g., X-rays, etc.) to pass through the soft X-ray filter and undergo filtering. For example, the frame structure may include a window through which light passes, and the soft X-ray filter may be spread out and laid in the window. For another example, the frame structure may be made of silicon.

The soft X-ray filter provided by the application can enable the passing rate of photons with the energy of 200-1000 eV to be more than or equal to 80%, the passing rate of photons with the energy of 400-1000eV to be more than or equal to 95%, and the photons with the energy of more than or equal to 1000eV can almost completely penetrate through the soft X-ray filter. The method of calculating the photon passage rate should be known to the person skilled in the art and can be obtained, for example, from the calculation tools available from the official networks of the Lorentsbury laboratory of America, see in particular https:// henke.

A second aspect of the present invention provides a method for manufacturing a soft X-ray filter provided by the first aspect of the present invention, including: and forming an aluminum film on the surface of the graphene support layer. Generally, an aluminum film may be formed on the surface of the fixed graphene support layer by a physical vapor deposition method (e.g., electron beam evaporation) or the like.

In the preparation method of the soft X-ray filter provided by the present application, the method may further include: and fixing the graphene support layer on the frame structure. The graphene support layer may be transferred to be fixed on the frame structure by a suitable method selected by those skilled in the art. For example, the graphene support layer may be placed in a suitable liquid phase (e.g., water, etc.) such that the graphene support layer is sufficiently spread apart and attached to the frame structure and sufficiently dried to provide the graphene support layer secured to the frame structure. In addition, if necessary, the graphene support layer may also be appropriately washed to remove other substances (e.g., PMMA part, etc.) on the surface thereof.

The soft X-ray filter provided by the application adopts the graphene as a supporting structure of the aluminum film, so that the transmittance of photons with the energy near 277eV can reach more than 90%, the problem of low transmittance of the existing filter in the energy range is solved, and the lowest transmittance of the photons with the energy range of 400-plus-1000 eV is more than 95%, particularly, the photons with the energy more than 1000eV are almost completely transmitted. In addition, the soft X-ray filter can adopt a silicon wafer as a supporting frame in the preparation process, is compatible with the existing semiconductor process, is beneficial to realizing batch production and customized processing, and has good industrialization prospect.

The present application is further illustrated by the following examples, which are not intended to limit the scope of the present application.

Example 1

A method of manufacturing the soft X-ray filter is described with reference to fig. 1.

And cutting and opening the silicon wafer by using femtosecond laser, processing the size of the opening part according to the requirement of a user, and supporting the upper graphene and the metal film by using the processed silicon wafer user as a frame. The aperture portion primarily serves as a window for X-rays to pass through. The silicon wafer used in the examples had a size of 20mm × 20mm, and a hole having a size of 10mm × 10mm was formed in the middle of the silicon wafer, thereby forming a frame for supporting a thin film (see step 1 in fig. 1).

Cleaning the surface of the silicon wafer with the opening with deionized water, drying at high temperature, floating the graphene coated with PMMA on the water surface, slowly fishing up the floating objects with the silicon wafer to enable the floating objects to be attached to the surface of the silicon wafer, and then drying to remove the water on the surface. The PMMA part of the surface was removed by soaking in an acetone solution for 30 minutes. And (4) drying after cleaning, and transferring the graphene to the surface of the silicon wafer (refer to step 2 in fig. 1). A physical representation of the transfer of graphene to the surface of the open-pore silicon wafer is shown in fig. 2. As can be seen from fig. 2, graphene can be firmly attached to the surface of the silicon wafer under intermolecular force, and graphene at the small hole is suspended to form a good window.

And (3) evaporating a layer of metal aluminum film with the thickness of about 40-50 nm on the surface of the graphene by using an electron beam evaporation technology, wherein the growth rate of the film is controlled to be about 2-3 nm/min (refer to step 3 in figure 1). A physical diagram of the graphene surface after being coated with an aluminum film by an e-book evaporation technique is shown in fig. 3. As can be seen from fig. 3, the aluminum film is well attached to the surface of the graphene, and can be roughly seen under the light of the lamp, and the filter can well block the transmission of the visible light.

In order to test the actual effect of the soft X-ray filter, the prepared filter is placed in a soft X-ray emission spectrometer, a titanium target X-ray source is used as a signal source, the characteristic energy of the titanium target X-ray source is 528eV, and a CCD detector is used for testing. The working principle of the X-ray source is that a tungsten filament lamp is used for generating hot electrons, and then the hot electrons bombard a titanium target under the action of an external electric field to generate characteristic X-rays, so that the visible light generated by the tungsten filament lamp is necessarily accompanied in the whole X-ray generation process. FIG. 4 is a comparison graph of measured signals of a CCD before and after adding a filter. Where FIGS. 4(a) and (c) are graphs of signals measured by a CCD detector before the filter is added, it can be seen that the intensity of the strongest part of the signal is about 3500; FIGS. 4(b) and (d) are the signals measured after adding filters. After the filter is added, the signal intensity is obviously reduced, and the strongest part of the signal is only about 370. The signal for the middle rectangular structure in FIG. 4(b) is the geometry of the X-ray source. By contrast, the signal in fig. 4(a) is mainly from the visible light emitted from the filament, while fig. 4(b) is a signal measured from soft X-rays generated by the titanium target, with a minimum intensity of 260, close to the background noise of the CCD detector. Therefore, the filter has good filtering effect on visible light, and can ensure that the soft X-ray has high transmittance.

In conclusion, the present invention effectively overcomes various disadvantages of the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.